115 results on '"Stella, A. L."'
Search Results
2. sj-pdf-1-wso-10.1177_17474930231182018 – Supplemental material for Occult contrast retention post-thrombectomy on 24-h follow-up dual-energy CT: Associations and impact on imaging analysis
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Pham, Jenny, Gan, Calvin, Dabboucy, Jasmin, Stella, Damien L, Dowling, Richard, Yan, Bernard, Bush, Steven, Williams, Cameron, Mitchell, Peter J, Desmond, Patricia, Thijs, Vincent, Asadi, Hamed, Brooks, Mark, Maingard, Julian, Jhamb, Ash, Pavlin-Premrl, Davor, Campbell, Bruce CV, and Ng, Felix C
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FOS: Clinical medicine ,Cardiology ,Medicine ,110904 Neurology and Neuromuscular Diseases - Abstract
Supplemental material, sj-pdf-1-wso-10.1177_17474930231182018 for Occult contrast retention post-thrombectomy on 24-h follow-up dual-energy CT: Associations and impact on imaging analysis by Jenny Pham, Calvin Gan, Jasmin Dabboucy, Damien L Stella, Richard Dowling, Bernard Yan, Steven Bush, Cameron Williams, Peter J Mitchell, Patricia Desmond, Vincent Thijs, Hamed Asadi, Mark Brooks, Julian Maingard, Ash Jhamb, Davor Pavlin-Premrl, Bruce CV Campbell and Felix C Ng in International Journal of Stroke
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- 2023
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3. Expression of a human cDNA in moss results in spliced mRNAs and fragmentary protein isoforms
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Bugra Oezdemir, Sebastian N. W. Hoernstein, Oguz Top, Ralf Reski, Stella W. L. Milferstaedt, Eva L. Decker, and Nico van Gessel
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Gene isoform ,Messenger RNA ,DNA, Complementary ,biology ,Functional protein ,Expression systems ,QH301-705.5 ,RNA Splicing ,Diseases ,Molecular engineering in plants ,Physcomitrella patens ,biology.organism_classification ,Plants, Genetically Modified ,Article ,Bryopsida ,Cell biology ,Complementary DNA ,RNA splicing ,Humans ,Protein Isoforms ,RNA, Messenger ,Biology (General) ,Gene - Abstract
Production of biopharmaceuticals relies on the expression of mammalian cDNAs in host organisms. Here we show that the expression of a human cDNA in the moss Physcomitrium patens generates the expected full-length and four additional transcripts due to unexpected splicing. This mRNA splicing results in non-functional protein isoforms, cellular misallocation of the proteins and low product yields. We integrated these results together with the results of our analysis of all 32,926 protein-encoding Physcomitrella genes and their 87,533 annotated transcripts in a web application, physCO, for automatized optimization. A thus optimized cDNA results in about twelve times more protein, which correctly localizes to the ER. An analysis of codon preferences of different production hosts suggests that similar effects occur also in non-plant hosts. We anticipate that the use of our methodology will prevent so far undetected mRNA heterosplicing resulting in maximized functional protein amounts for basic biology and biotechnology., Top et al. report the expression of a human blood-clotting factor IX-encoding cDNA in the moss Physcomitrium patens and demonstrate that in addition to the unspliced full-length transcript, the splicing machinery produced several different transcripts, and thus different protein isoforms, which the authors designate as heterosplicing. The authors present a web application, physCO, to automatize the process of P. patens-specific codon optimization, a tool that can assist in maximized functional protein amounts for biotechnology.
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- 2021
4. Absence of precursor incommensurate charge order in electronic nematic Ba0.35Sr0.65Ni2As2
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John Collini, Sangjun Lee, Stella X.-L. Sun, Chris Eckberg, Daniel J. Campbell, Peter Abbamonte, and Johnpierre Paglione
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- 2022
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5. Supersite at Iqaluit: The Canadian Arctic Weather Science Project
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Jason A. Milbrandt, Robert W. Crawford, Armin Deghan, Paul Joe, Gabrielle Gascon, Barbara Casati, Zen Mariani, Stella M. L. Melo, Kevin Strawbridge, and William R. Burrows
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Atmospheric Science ,Geography ,Arctic ,Climatology - Published
- 2020
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6. The Canadian Arctic Weather Science Project: Introduction to the Iqaluit Site
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Zen Mariani, Armin Deghan, Robert W. Crawford, Paul Joe, Barbara Casati, Jason A. Milbrandt, Stella M. L. Melo, Gabrielle Gascon, Kevin Strawbridge, and William R. Burrows
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Atmospheric Science ,Arctic ,business.industry ,Operational monitoring ,Environmental resource management ,Climate change ,Environmental science ,business - Abstract
The goal of the Canadian Arctic Weather Science (CAWS) project is to conduct research into the future operational monitoring and forecasting programs of Environment and Climate Change Canada in the Arctic where increased economic and recreational activities are expected with enhanced transportation and search and rescue requirements. Due to cost, remoteness and vast geographical coverage, the future monitoring concept includes a combination of space-based observations, sparse in situ surface measurements, and advanced reference sites. A prototype reference site has been established at Iqaluit, Nunavut (63°45'N, 68°33'W), that includes a Ka-band radar, water vapor lidars (both in-house and commercial versions), multiple Doppler lidars, ceilometers, radiation flux, and precipitation sensors. The scope of the project includes understanding of the polar processes, evaluating new technologies, validation of satellite products, validation of numerical weather prediction systems, development of warning products, and communication of their risk to a variety of users. This contribution will provide an overview of the CAWS project to show some preliminary results and to encourage collaborations.
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- 2020
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7. Multiple Charge Density Waves and Superconductivity Nucleation at Antiphase Domain Walls in the Nematic Pnictide Ba1−xSrxNi2As2
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Chris Eckberg, Eduardo Fradkin, Johnpierre Paglione, Matteo Mitrano, Peter Abbamonte, Xuefei Guo, Stella X.-L. Sun, Sangjun Lee, and John Collini
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Superconductivity ,Quantum phase transition ,Physics ,Condensed matter physics ,Lattice (group) ,Center (category theory) ,General Physics and Astronomy ,Order (ring theory) ,Charge (physics) ,Coupling (probability) ,01 natural sciences ,010305 fluids & plasmas ,Condensed Matter::Superconductivity ,0103 physical sciences ,010306 general physics ,Charge density wave - Abstract
How superconductivity interacts with charge or nematic order is one of the great unresolved issues at the center of research in quantum materials. ${\mathrm{Ba}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{Ni}}_{2}{\mathrm{As}}_{2}$ (BSNA) is a charge ordered pnictide superconductor recently shown to exhibit a sixfold enhancement of superconductivity due to nematic fluctuations near a quantum phase transition (at ${x}_{c}=0.7$) [1]. The superconductivity is, however, anomalous, with the resistive transition for $0.4lxl{x}_{c}$ occurring at a higher temperature than the specific heat anomaly. Using x-ray scattering, we discovered a new charge density wave (CDW) in BSNA in this composition range. The CDW is commensurate with a period of two lattice parameters, and is distinct from the two CDWs previously reported in this material [1,2]. We argue that the anomalous transport behavior arises from heterogeneous superconductivity nucleating at antiphase domain walls in this CDW. We also present new data on the incommensurate CDW, previously identified as being unidirectional [2], showing that it is a rotationally symmetric ``$4Q$'' state with ${C}_{4}$ symmetry. Our study establishes BSNA as a rare material containing three distinct CDWs, and an exciting test bed for studying coupling between CDW, nematic, and SC orders.
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- 2021
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8. Multiple Charge Density Waves and Superconductivity Nucleation at Antiphase Domain Walls in the Nematic Pnictide Ba_{1-x}Sr_{x}Ni_{2}As_{2}
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Sangjun, Lee, John, Collini, Stella X-L, Sun, Matteo, Mitrano, Xuefei, Guo, Chris, Eckberg, Johnpierre, Paglione, Eduardo, Fradkin, and Peter, Abbamonte
- Abstract
How superconductivity interacts with charge or nematic order is one of the great unresolved issues at the center of research in quantum materials. Ba_{1-x}Sr_{x}Ni_{2}As_{2} (BSNA) is a charge ordered pnictide superconductor recently shown to exhibit a sixfold enhancement of superconductivity due to nematic fluctuations near a quantum phase transition (at x_{c}=0.7) [1]. The superconductivity is, however, anomalous, with the resistive transition for 0.4xx_{c} occurring at a higher temperature than the specific heat anomaly. Using x-ray scattering, we discovered a new charge density wave (CDW) in BSNA in this composition range. The CDW is commensurate with a period of two lattice parameters, and is distinct from the two CDWs previously reported in this material [1,2]. We argue that the anomalous transport behavior arises from heterogeneous superconductivity nucleating at antiphase domain walls in this CDW. We also present new data on the incommensurate CDW, previously identified as being unidirectional [2], showing that it is a rotationally symmetric "4Q" state with C_{4} symmetry. Our study establishes BSNA as a rare material containing three distinct CDWs, and an exciting test bed for studying coupling between CDW, nematic, and SC orders.
- Published
- 2021
9. Multiple charge density waves and superconductivity nucleation at antiphase domain walls in the nematic pnictide Ba$_{1-x}$Sr$_{x}$Ni$_{2}$As$_{2}$
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Lee, Sangjun, Collini, John, Sun, Stella X. -L., Mitrano, Matteo, Guo, Xuefei, Eckberg, Chris, Paglione, Johnpierre, Fradkin, Eduardo, and Abbamonte, Peter
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Superconductivity (cond-mat.supr-con) ,Condensed Matter - Strongly Correlated Electrons ,Strongly Correlated Electrons (cond-mat.str-el) ,Condensed Matter - Superconductivity ,Condensed Matter::Superconductivity ,FOS: Physical sciences ,Condensed Matter::Strongly Correlated Electrons - Abstract
How superconductivity interacts with charge or nematic order is one of the great unresolved issues at the center of research in quantum materials. Ba$_{1-x}$Sr$_{x}$Ni$_{2}$As$_{2}$ (BSNA) is a charge ordered pnictide superconductor recently shown to exhibit a six-fold enhancement of superconductivity due to nematic fluctuations near a quantum phase transition (at $x_c=0.7$). The superconductivity is, however, anomalous, with the resistive transition for $0.4 < x< x_c$ occurring at a higher temperature than the specific heat anomaly. Using x-ray scattering, we discovered a new charge density wave (CDW) in BSNA in this composition range. The CDW is commensurate with a period of two lattice parameters, and is distinct from the two CDWs previously reported in this material. We argue that the anomalous transport behavior arises from heterogeneous superconductivity nucleating at antiphase domain walls in this CDW. We also present new data on the incommensurate CDW, previously identified as being unidirectional, showing that is a rotationally symmetric, "4$Q$" state with $C_4$ symmetry. Our study establishes BSNA as a rare material containing three distinct CDWs, and an exciting testbed for studying coupling between CDW, nematic, and SC orders., 5 pages, 5 figures + supplemental material document
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- 2021
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10. Absence of precursor incommensurate charge order in electronic nematic Ba0.35Sr0.65Ni2As2
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Collini, John, Lee, Sangjun, Sun, Stella X. -L., Eckberg, Chris, Campbell, Daniel, Lynn, Jeffrey W., Abbamonte, Peter, and Paglione, Johnpierre
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Superconductivity (cond-mat.supr-con) ,Condensed Matter - Strongly Correlated Electrons ,Strongly Correlated Electrons (cond-mat.str-el) ,Condensed Matter - Superconductivity ,FOS: Physical sciences - Abstract
Recent discoveries of charge order and electronic nematic order in the iron-based superconductors and cuprates have pointed towards the possibility of nematic and charge fluctuations playing a role in the enhancement of superconductivity. The Ba1-xSrxNi2As2 system, closely related in structure to the BaFe2As2 system, has recently been shown to exhibit both types of ordering without the presence of any magnetic order. We report single crystal X-ray diffraction, resistance transport measurements, and magnetization of \BaSrLate, providing evidence that the previously reported incommensurate charge order with wavevector $(0,0.28,0)_{tet}$ in the tetragonal state of \BaNi~vanishes by this concentration of Sr substitution together with nematic order. Our measurements suggest that the nematic and incommensurate charge orders are closely tied in the tetragonal state, and show that the $(0,0.33,0)_{tri}$ charge ordering in the triclinic phase of BaNi2As2 evolves to become $(0,0.5,0)_{tri}$ charge ordering at $x$=0.65 before vanishing at $x$=0.71., Comment: 4 pages, 3 figures
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- 2021
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11. Enhanced Electron-Phonon Coupling for Charge-Density-Wave Formation in La1.8−xEu0.2SrxCuO4+δ
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Ignace Jarrige, Alexander Zakrzewski, Gregory MacDougall, Matteo Mitrano, Andi Barbour, Thomas A. Johnson, Ali Husain, Valentina Bisogni, Yingying Peng, Peter Abbamonte, and Stella X.-L. Sun
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Physics ,Superconductivity ,Condensed matter physics ,Phonon ,General Physics and Astronomy ,Order (ring theory) ,Charge (physics) ,Coupling (probability) ,01 natural sciences ,Condensed Matter::Superconductivity ,0103 physical sciences ,Condensed Matter::Strongly Correlated Electrons ,Cuprate ,Absorption (logic) ,010306 general physics ,Charge density wave - Abstract
Charge density wave (CDW) correlations are prevalent in all copper-oxide superconductors. While CDWs in conventional metals are driven by coupling between lattice vibrations and electrons, the role of the electron-phonon coupling (EPC) in cuprate CDWs is strongly debated. Using Cu ${L}_{3}$ edge resonant inelastic x-ray scattering, we study the CDW and Cu-O bond-stretching phonons in the stripe-ordered cuprate ${\mathrm{La}}_{1.8\ensuremath{-}x}{\mathrm{Eu}}_{0.2}{\mathrm{Sr}}_{x}{\mathrm{CuO}}_{4+\ensuremath{\delta}}$. We investigate the interplay between charge order and EPC as a function of doping and temperature and find that the EPC is enhanced in a narrow momentum region around the CDW ordering vector. By detuning the incident photon energy from the absorption resonance, we extract an EPC matrix element at the CDW ordering vector of $M\ensuremath{\simeq}0.36\text{ }\text{ }\mathrm{eV}$, which decreases to $M\ensuremath{\simeq}0.30\text{ }\text{ }\mathrm{eV}$ at high temperature in the absence of the CDW. Our results suggest a feedback mechanism in which the CDW enhances the EPC which, in turn, further stabilizes the CDW.
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- 2020
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12. Deep learning in finance and banking: A literature review and classification
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Junyi Chai, Stella P. L. Cho, and Jian Huang
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Finance ,0209 industrial biotechnology ,Data processing ,Public Administration ,business.industry ,Computer science ,Deep learning ,02 engineering and technology ,General Business, Management and Accounting ,020901 industrial engineering & automation ,Human resource management ,Research community ,0202 electrical engineering, electronic engineering, information engineering ,Key (cryptography) ,Preprocessor ,020201 artificial intelligence & image processing ,Artificial intelligence ,business - Abstract
Deep learning has been widely applied in computer vision, natural language processing, and audio-visual recognition. The overwhelming success of deep learning as a data processing technique has sparked the interest of the research community. Given the proliferation of Fintech in recent years, the use of deep learning in finance and banking services has become prevalent. However, a detailed survey of the applications of deep learning in finance and banking is lacking in the existing literature. This study surveys and analyzes the literature on the application of deep learning models in the key finance and banking domains to provide a systematic evaluation of the model preprocessing, input data, and model evaluation. Finally, we discuss three aspects that could affect the outcomes of financial deep learning models. This study provides academics and practitioners with insight and direction on the state-of-the-art of the application of deep learning models in finance and banking.
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- 2020
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13. Government involvement in banking systems and economic growth: a comparison across countries
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Tina T. He, Stella P. L. Cho, and Wilson X. B. Li
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German ,Economics and Econometrics ,Government ,Sociology and Political Science ,Economy ,Political science ,Political Science and International Relations ,language ,China ,language.human_language - Abstract
This study investigates 92 countries of different legal origins, including 25 English origin, 44 French origin, 11 Scandinavian and German origin, and 12 socialist origin countries. Compare...
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- 2019
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14. Resonant Soft X-Ray Scattering from Stripe-Ordered La2−xBaxCuO4 Detected by a Transition-Edge Sensor Array Detector
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Sangjun Lee, William B. Doriese, Fanny Rodolakis, Young Il Joe, Kelsey M. Morgan, Yizhi Fang, Jessica L. McChesney, Joel N. Ullom, Gilberto De La Pena, Joseph W. Fowler, Daniel S. Swetz, Leila R. Vale, Peter Abbamonte, and Stella X.-L. Sun
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Physics ,Superconductivity ,Degree (graph theory) ,Scattering ,Resolution (electron density) ,General Physics and Astronomy ,Resonance ,Order (ring theory) ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,0103 physical sciences ,Transition edge sensor ,Atomic physics ,010306 general physics ,0210 nano-technology ,Energy (signal processing) - Abstract
Resonant soft x-ray scattering (RSXS) is a leading probe of valence-band order in materials best known for detecting charge-density-wave order in copper-oxide superconductors. One of the biggest limitations on the RSXS technique is the presence of a severe fluorescence background, which, like the RSXS cross section itself, is enhanced under resonant conditions. This background prevents the study of weak signals such as diffuse scattering from glassy or fluctuating order that is spread widely over momentum space. Recent advances in superconducting transition-edge-sensor (TES) detectors have led to major improvements in energy resolution and detection efficiency in the soft x-ray range. Here, we perform a RSXS study of stripe-ordered ${\mathrm{La}}_{2\ensuremath{-}x}{\mathrm{Ba}}_{x}{\mathrm{Cu}\mathrm{O}}_{4}$ at the $\mathrm{Cu}$ ${L}_{3/2}$ edge (932.2 eV) using a TES detector with 1.5-eV resolution, to evaluate its utility for mitigating the fluorescence-background problem. We find that, for suitable degree of detuning from the resonance, the TES rejects the fluorescence background, leading to a five to ten times improvement in the statistical quality of the data compared to an equivalent, energy-integrated measurement. We conclude that a TES presents a promising approach to reducing background in RSXS studies and may lead to discoveries in materials exhibiting valence-band order that is fluctuating or glassy.
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- 2020
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15. An Overview of Surface-Based Precipitation Observations at Environment and Climate Change Canada
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Rodica Nitu, Alex Zucconi, Stella M. L. Melo, Qian Li, Jeffery Hoover, Eva Mekis, Norman Donaldson, and Janti Reid
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Atmospheric Science ,Data processing ,Service (systems architecture) ,010504 meteorology & atmospheric sciences ,Meteorology ,0208 environmental biotechnology ,Climate change ,Context (language use) ,02 engineering and technology ,Oceanography ,Snow ,01 natural sciences ,020801 environmental engineering ,law.invention ,Work (electrical) ,law ,Environmental science ,Precipitation ,Radar ,0105 earth and related environmental sciences - Abstract
The objective of this paper is to provide an overview of the present status and procedures related to surface precipitation observations at Environment and Climate Change Canada (ECCC). This work was done to support the ongoing renewal of observation systems and networks at the Meteorological Service of Canada. The paper focusses on selected parameters, namely, accumulated precipitation, precipitation intensity, precipitation type, rainfall, snowfall, and radar reflectivity. Application-specific user needs and requirements are defined and captured by World Meteorological Organization (WMO) Expert Teams at the international level by Observing Systems Capability Analysis and Review (OSCAR) and WMO Integrated Global Observing System (WIGOS), and by ECCC user engagement initiatives within the Canadian context. The precipitation-related networks of ECCC are separated into those containing automatic instruments, those with human (manual) observers, and the radar network. The unique characteristics and d...
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- 2018
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16. Evidence for photoinduced sliding of the charge-order condensate in La1.875Ba0.125CuO4
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Sangjun Lee, G. D. Gu, John Schneeloch, Matteo Mitrano, Young Il Joe, Scott F. Wandel, Alexander H. Reid, William F. Schlotter, Nigel Goldenfeld, Minhui Zhu, Ali Husain, Peter Abbamonte, Giacomo Coslovich, Stella X.-L. Sun, Tim Brandt van Driel, and Gilberto de la Peña Munoz
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Superconductivity ,Materials science ,Field (physics) ,Condensed matter physics ,Lattice (group) ,Order (ring theory) ,Charge (physics) ,02 engineering and technology ,Electron ,021001 nanoscience & nanotechnology ,01 natural sciences ,Condensed Matter::Superconductivity ,0103 physical sciences ,010306 general physics ,0210 nano-technology ,Quantum ,Charge density wave - Abstract
Electrons and holes in quantum materials often self-organize into ordered electronic phases, such as charge or spin density waves. These states are widely regarded as competing with superconductivity, and achieving their control could lead to higher superconducting transition temperatures. By using ultrafast optical and soft x-ray pulses, here, the authors observe a novel sliding state of the charge density wave in the cuprate superconductor La${}_{1.875}$Ba${}_{0.125}$CuO${}_{4}$, in which the condensate translates with respect to the lattice due to the ultrafast pump field.
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- 2019
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17. Ultrafast time-resolved x-ray scattering reveals diffusive charge order dynamics in La 2– x Ba x CuO 4
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Young Il Joe, John Schneeloch, Gilberto de la Peña Munoz, Alexander H. Reid, G. D. Gu, Scott F. Wandel, Minhui Zhu, Luca V. Delacrétaz, Ali Husain, Peter Abbamonte, Giacomo Coslovich, Nigel Goldenfeld, Stella X.-L. Sun, Sean A. Hartnoll, Tim Brandt van Driel, Matteo Mitrano, William F. Schlotter, and Sangjun Lee
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Superconductivity ,Physics ,Multidisciplinary ,Condensed matter physics ,Scattering ,Charge (physics) ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Topological defect ,Condensed Matter::Superconductivity ,Picosecond ,Pairing ,0103 physical sciences ,Cuprate ,010306 general physics ,0210 nano-technology ,Quantum tunnelling - Abstract
Charge order is universal among high-Tc cuprates, but its relation to superconductivity is unclear. While static order competes with superconductivity, dynamic order may be favorable and even contribute to Cooper pairing. Using time-resolved resonant soft x-ray scattering at a free-electron laser, we show that the charge order in prototypical La2−xBaxCuO4 exhibits transverse fluctuations at picosecond time scales. These sub–millielectron volt excitations propagate by Brownian-like diffusion and have an energy scale remarkably close to the superconducting Tc. At sub–millielectron volt energy scales, the dynamics are governed by universal scaling laws defined by the propagation of topological defects. Our results show that charge order in La2−xBaxCuO4 exhibits dynamics favorable to the in-plane superconducting tunneling and establish time-resolved x-rays as a means to study excitations at energy scales inaccessible to conventional scattering techniques.
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- 2019
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18. Unconventional Charge Density Wave Order in the Pnictide Superconductor Ba(Ni1−xCox)2As2
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Gilberto De La Pena, Sangjun Lee, Daniel Campbell, Matteo Mitrano, Johnpierre Paglione, Jun-Sik Lee, Yizhi Fang, Peter Abbamonte, John Collini, Chris Eckberg, F. M. F. de Groot, Hoyoung Jang, and Stella X.-L. Sun
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Superconductivity ,Physics ,High-temperature superconductivity ,General Physics and Astronomy ,Order (ring theory) ,Fermi surface ,Triclinic crystal system ,law.invention ,Crystallography ,law ,Condensed Matter::Superconductivity ,Antiferromagnetism ,Condensed Matter::Strongly Correlated Electrons ,Pnictogen ,Charge density wave - Abstract
$\mathrm{Ba}({\mathrm{Ni}}_{1\ensuremath{-}x}{\mathrm{Co}}_{x}{)}_{2}{\mathrm{As}}_{2}$ is a structural homologue of the pnictide high temperature superconductor, $\mathrm{Ba}({\mathrm{Fe}}_{1\ensuremath{-}x}{\mathrm{Co}}_{x}{)}_{2}{\mathrm{As}}_{2}$, in which the Fe atoms are replaced by Ni. Superconductivity is highly suppressed in this system, reaching a maximum ${T}_{c}=2.3\text{ }\text{ }\mathrm{K}$, compared to 24 K in its iron-based cousin, and the origin of this ${T}_{c}$ suppression is not known. Using x-ray scattering, we show that $\mathrm{Ba}({\mathrm{Ni}}_{1\ensuremath{-}x}{\mathrm{Co}}_{x}{)}_{2}{\mathrm{As}}_{2}$ exhibits a unidirectional charge density wave (CDW) at its triclinic phase transition. The CDW is incommensurate, exhibits a sizable lattice distortion, and is accompanied by the appearance of $\ensuremath{\alpha}$ Fermi surface pockets in photoemission [B. Zhou et al., Phys. Rev. B 83, 035110 (2011)], suggesting it forms by an unconventional mechanism. Co doping suppresses the CDW, paralleling the behavior of antiferromagnetism in iron-based superconductors. Our study demonstrates that pnictide superconductors can exhibit competing CDW order, which may be the origin of ${T}_{c}$ suppression in this system.
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- 2019
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19. Unconventional Charge Density Wave Order in the Pnictide Superconductor Ba(Ni1-xCox)(2)As-2
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Lee, Sangjun, de la Pena, Gilberto, Sun, Stella X-L, Mitrano, Matteo, Fang, Yizhi, Jang, Hoyoung, Lee, Jun-Sik, Eckberg, Chris, Campbell, Daniel, Collini, John, Paglione, Johnpierre, de Groot, F. M. F., Abbamonte, Peter, Sub Inorganic Chemistry and Catalysis, and Inorganic Chemistry and Catalysis
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Taverne - Abstract
Ba(Ni1−xCox)2As2 is a structural homologue of the pnictide high temperature superconductor, Ba(Fe1−xCox)2As2, in which the Fe atoms are replaced by Ni. Superconductivity is highly suppressed in this system, reaching a maximum Tc=2.3 K, compared to 24 K in its iron-based cousin, and the origin of this Tc suppression is not known. Using x-ray scattering, we show that Ba(Ni1−xCox)2As2 exhibits a unidirectional charge density wave (CDW) at its triclinic phase transition. The CDW is incommensurate, exhibits a sizable lattice distortion, and is accompanied by the appearance of α Fermi surface pockets in photoemission [B. Zhou et al., Phys. Rev. B 83, 035110 (2011)], suggesting it forms by an unconventional mechanism. Co doping suppresses the CDW, paralleling the behavior of antiferromagnetism in iron-based superconductors. Our study demonstrates that pnictide superconductors can exhibit competing CDW order, which may be the origin of Tc suppression in this system.
- Published
- 2019
20. Unconventional Charge Density Wave Order in the Pnictide Superconductor Ba(Ni1-xCox)(2)As-2
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Lee, Sangjun, de la Pena, Gilberto, Sun, Stella X-L, Mitrano, Matteo, Fang, Yizhi, Jang, Hoyoung, Lee, Jun-Sik, Eckberg, Chris, Campbell, Daniel, Collini, John, Paglione, Johnpierre, de Groot, F. M. F., Abbamonte, Peter, Sub Inorganic Chemistry and Catalysis, and Inorganic Chemistry and Catalysis
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Taverne - Abstract
Ba(Ni1−xCox)2As2 is a structural homologue of the pnictide high temperature superconductor, Ba(Fe1−xCox)2As2, in which the Fe atoms are replaced by Ni. Superconductivity is highly suppressed in this system, reaching a maximum Tc=2.3 K, compared to 24 K in its iron-based cousin, and the origin of this Tc suppression is not known. Using x-ray scattering, we show that Ba(Ni1−xCox)2As2 exhibits a unidirectional charge density wave (CDW) at its triclinic phase transition. The CDW is incommensurate, exhibits a sizable lattice distortion, and is accompanied by the appearance of α Fermi surface pockets in photoemission [B. Zhou et al., Phys. Rev. B 83, 035110 (2011)], suggesting it forms by an unconventional mechanism. Co doping suppresses the CDW, paralleling the behavior of antiferromagnetism in iron-based superconductors. Our study demonstrates that pnictide superconductors can exhibit competing CDW order, which may be the origin of Tc suppression in this system.
- Published
- 2019
21. State of the Climate in 2018
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Ades, M., Adler, R., Aldeco, Laura S., Alejandra, G., Alfaro, Eric J., Aliaga-Nestares, Vannia, Allan, Richard P., Allan, Rob, Alves, Lincoln M., Amador, Jorge A., Andersen, J. K., Anderson, John, Arndt, Derek S., Arosio, C., Arrigo, Kevin, Azorin-Molina, César, Bardin, M. Yu, Barichivich, Jonathan, Barreira, Sandra, Baxter, Stephen, Beck, H. E., Becker, Andreas, Bell, Gerald D., Bellouin, Nicolas, Belmont, M., Benedetti, Angela, Benedict, Imme, Bernhard, G. H., Berrisford, Paul, Berry, David I., Bettio, Lynette, Bhatt, U. S., Biskaborn, B. K., Bissolli, Peter, Bjella, Kevin L., Bjerke, J. K., Blake, Eric S., Blenkinsop, Stephen, Blunden, Jessica, Bock, Olivier, Bosilovich, Michael G., Boucher, Olivier, Box, J. E., Boyer, Tim, Braathen, Geir, Bringas, Francis G., Bromwich, David H., Brown, Alrick, Brown, R., Brown, Timothy J., Buehler, S. A., Cáceres, Luis, Calderón, Blanca, Camargo, Suzana J., Campbell, Jayaka D., Campos Diaz, Diego A., Cappelen, J., Carrea, Laura, Carrier, Seth B., Carter, Brendan R., Castro, Anabel Y., Cetinic, Ivona, Chambers, Don P., Chen, Lin, Cheng, Lijing, Cheng, Vincent Y.S., Christiansen, Hanne H., Christy, John R., Chung, E. S., Claus, Federico, Clem, Kyle R., Coelho, Caio A.S., Coldewey-Egbers, Melanie, Colwell, Steve, Cooper, Owen R., Cosca, Cathy, Covey, Curt, Coy, Lawrence, Dávila, Cristina P., Davis, Sean M., de Eyto, Elvira, de Jeu, Richard A.M., De Laat, Jos, Decharme, B., Degasperi, Curtis L., Degenstein, Doug, Demircan, Mesut, Derksen, C., Dhurmea, K. R., Di Girolamo, Larry, Diamond, Howard J., Diaz, Eliecer, Diniz, Fransisco A., Dlugokencky, Ed J., Dohan, Kathleen, Dokulil, Martin T., Dolman, A. Johannes, Domingues, Catia M., Domingues, Ricardo, Donat, Markus G., Dorigo, Wouter A., Drozdov, D. S., Druckenmiller, Matthew L., Dunn, Robert J.H., Durre, Imke, Dutton, Geoff S., Elkharrim, M., Elkins, James W., Epstein, H. E., Espinoza, Jhan C., Famiglietti, James S., Farrell, Sinead L., Fausto, R. S., Feely, Richard A., Feng, Z., Fenimore, Chris, Fettweis, X., Fioletov, Vitali E., Flemming, Johannes, Fogt, Ryan L., Forbes, B. C., Foster, Michael J., Francis, S. D., Franz, Bryan A., Frey, Richard A., Frith, Stacey M., Froidevaux, Lucien, Ganter, Catherine, Garforth, J., Gerland, Sebastian, Gilson, John, Gleason, Karin, Gobron, Nadine, Goetz, S., Goldenberg, Stanley B., Goni, Gustavo, Gray, Alison, Grooß, Jens Uwe, Gruber, Alexander, Gu, Guojun, Guard, Charles Chip P., Gupta, S. K., Gutiérrez, Dimitri, Haas, Christian, Hagos, S., Hahn, Sebastian, Haimberger, Leo, Hall, Brad D., Halpert, Michael S., Hamlington, Benjamin D., Hanna, E., Hanssen-Bauer, I., Harris, Ian, Hazeleger, Wilco, He, Q., Heidinger, Andrew K., Heim, Richard R., Hemming, D. L., Hendricks, Stefan, Hernández, Rafael, Hersbach, H. E., Hidalgo, Hugo G., Ho, Shu Peng Ben, Holmes, R. M., Hu, Chuanmin, Huang, Boyin, Hubbard, Katherine, Hubert, Daan, Hurst, Dale F., Ialongo, Iolanda, Ijampy, J. A., Inness, Antje, Isaac, Victor, Isaksen, K., Ishii, Masayoshi, Jeffries, Martin O., Jevrejeva, Svetlana, Jia, G., Jiménez, C., Jin, Xiangze, John, Viju, Johnsen, Bjørn, Johnson, Gregory C., Johnson, Kenneth S., Johnson, Bryan, Jones, Philip D., Jumaux, Guillaume, Kabidi, Khadija, Kaiser, J. W., Karaköylü, Erdem M., Karlsen, S. R., Karnauskas, Mandy, Kato, Seiji, Kazemi, A. Fazl, Kelble, Christopher, Keller, Linda M., Kennedy, John, Kholodov, A. L., Khoshkam, Mahbobeh, Kidd, R., Killick, Rachel, Kim, Hyungjun, Kim, S. J., King, A. D., King, Brian A., Kipling, Z., Klotzbach, Philip J., Knaff, John A., Korhonen, Johanna, Korshunova, Natalia N., Kramarova, Natalya A., Kratz, D. P., Kruger, Andries, Kruk, Michael C., Krumpen, Thomas, Labbé, L., Ladd, C., Lakatos, Mónika, Lakkala, Kaisa, Lander, Mark A., Landschützer, Peter, Landsea, Chris W., Lareau, Neil P., Lavado-Casimiro, Waldo, Lazzara, Matthew A., Lee, T. C., Leuliette, Eric, L’heureux, Michelle, Li, Bailing, Li, Tim, Lieser, Jan L., Lim, J. Y., Lin, I. I., Liu, Hongxing, Locarnini, Ricardo, Loeb, Norman G., Long, Craig S., López, Luis A., Lorrey, Andrew M., Loyola, Diego, Lumpkin, Rick, Luo, Jing Jia, Luojus, K., Lyman, John M., Malkova, G. V., Manney, Gloria L., Marchenko, S. S., Marengo, José A., Marin, Dora, Marquardt Collow, Allison B., Marra, John J., Marszelewski, Wlodzimierz, Martens, B., Martínez-Güingla, Rodney, Massom, Robert A., May, Linda, Mayer, Michael, Mazloff, Matthew, McBride, Charlotte, McCabe, M., McClelland, J. W., McEvoy, Daniel J., McGree, Simon, McVicar, Tim R., Mears, Carl A., Meier, Walt, Meijers, Andrew, Mekonnen, Ademe, Mengistu Tsidu, G., Menzel, W. Paul, Merchant, Christopher J., Meredith, Michael P., Merrifield, Mark A., Miller, Ben, Miralles, Diego G., Misevicius, Noelia, Mitchum, Gary T., Mochizuki, Y., Monselesan, Didier, Montzka, Stephen A., Mora, Natali, Morice, Colin, Mosquera-Vásquez, Kobi, Mostafa, Awatif E., Mote, T., Mudryk, L., Mühle, Jens, Mullan, A. Brett, Müller, Rolf, Myneni, R., Nash, Eric R., Nauslar, Nicholas J., Nerem, R. Steven, Newman, Paul A., Nicolas, Julien P., Nieto, Juan José, Noetzli, Jeannette, Osborn, Tim J., Osborne, Emily, Overland, J., Oyunjargal, Lamjav, Park, T., Pasch, Richard J., Pascual Ramírez, Reynaldo, Pastor Saavedra, Maria Asuncion, Paterson, Andrew M., Pearce, Petra R., Pelto, Mauri S., Perovich, Don, Petropavlovskikh, Irina, Pezza, Alexandre B., Phillips, C., Phillips, David, Phoenix, G., Pinty, Bernard, Pitts, Michael, Po-Chedley, S., Polashenski, Chris, Preimesberger, W., Purkey, Sarah G., Quispe, Nelson, Rajeevan, Madhavan, Rakotoarimalala, C. L., Ramos, Andrea M., Ramos, Isabel, Randel, W., Raynolds, M. K., Reagan, James, Reid, Phillip, Reimer, Christoph, Rémy, Samuel, Revadekar, Jayashree V., Richardson, A. D., Richter-Menge, Jacqueline, Ricker, Robert, Ripaldi, A., Robinson, David A., Rodell, Matthew, Rodriguez Camino, Ernesto, Romanovsky, Vladimir E., Ronchail, Josyane, Rosenlof, Karen H., Rösner, Benajamin, Roth, Chris, Rozanov, A., Rusak, James A., Rustemeier, Elke, Rutishäuser, T., Sallée, Jean Baptiste, Sánchez-Lugo, Ahira, Santee, Michelle L., Sawaengphokhai, P., Sayouri, Amal, Scambos, Ted A., Scanlon, T., Scardilli, Alvaro S., Schenzinger, Verena, Schladow, S. Geoffey, Schmid, Claudia, Schmid, Martin, Schoeneich, P., Schreck, Carl J., Selkirk, H. B., Sensoy, Serhat, Shi, Lei, Shiklomanov, A. I., Shiklomanov, Nikolai I., Shimpo, A., Shuman, Christopher A., Siegel, David A., Sima, Fatou, Simmons, Adrian J., Smeets, C. J.P.P., Smith, Adam, Smith, Sharon L., Soden, B., Sofieva, Viktoria, Sparks, T. H., Spence, Jacqueline, Spencer, R. G.M., Spillane, Sandra, Srivastava, A. K., Stabeno, P. J., Stackhouse, Paul W., Stammerjohn, Sharon, Stanitski, Diane M., Steinbrecht, Wolfgang, Stella, José L., Stengel, M., Stephenson, Tannecia S., Strahan, Susan E., Streeter, Casey, Streletskiy, Dimitri A., Sun-Mack, Sunny, Suslova, A., Sutton, Adrienne J., Swart, Sebastiann, Sweet, William, Takahashi, Kenneth S., Tank, S. E., Taylor, Michael A., Tedesco, M., Thackeray, S. J., Thompson, Philip R., Timbal, Bertrand, Timmermans, M. L., Tobin, Skie, Tømmervik, H., Tourpali, Kleareti, Trachte, Katja, Tretiakov, M., Trewin, Blair C., Triñanes, Joaquin A., Trotman, Adrian R., Tschudi, Mark, Tye, Mari R., van As, D., van de Wal, R. S.W., van der A, Ronald J., van der Schalie, Robin, van der Schrier, Gerard, van der Werf, Guido R., van Heerwaarden, Chiel, Van Meerbeeck, Cedric J., Verburg, Piet, Vieira, G., Vincent, Lucie A., Vömel, Holger, Vose, Russell S., Walker, D. A., Walsh, J. E., Wang, Bin, Wang, Hui, Wang, Lei, Wang, M., Wang, Mengqiu, Wang, Ray, Wang, Sheng Hung, Wanninkhof, Rik, Watanabe, Shohei, Weber, Mark, Webster, Melinda, Weerts, Albrecht, Weller, Robert A., Westberry, Toby K., Weyhenmeyer, Gesa A., Widlansky, Matthew J., Wijffels, Susan E., Wilber, Anne C., Wild, Jeanette D., Willett, Kate M., Wong, Takmeng, Wood, E. F., Woolway, R. Iestyn, Xue, Yan, Yin, Xungang, Yu, Lisan, Zambrano, Eduardo, Zeyaeyan, Sadegh, Zhang, Huai Min, Zhang, Peiqun, Zhao, Guanguo, Zhao, Lin, Zhou, Xinjia, Zhu, Zhiwei, Ziemke, Jerry R., Ziese, Markus, Andersen, Andrea, Griffin, Jessicca, Hammer, Gregory, Love-Brotak, S. Elizabeth, Misch, Deborah J., Riddle, Deborah B., Veasey, Sara W., Processus et interactions de fine échelle océanique (PROTEO), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Océan et variabilité du climat (VARCLIM), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Berry, David, Jevrejeva, Svetlana, King, Brian, and Domingues, Catia
- Subjects
Surface (mathematics) ,Atmospheric Science ,Materials science ,010504 meteorology & atmospheric sciences ,0207 environmental engineering ,Mineralogy ,[PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph] ,02 engineering and technology ,01 natural sciences ,ComputingMethodologies_DOCUMENTANDTEXTPROCESSING ,SDG 13 - Climate Action ,SDG 14 - Life Below Water ,020701 environmental engineering ,GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries) ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences - Abstract
In 2018, the dominant greenhouse gases released into Earth's atmosphere-carbon dioxide, methane, and nitrous oxide-continued their increase. The annual global average carbon dioxide concentration at Earth's surface was 407.4 ± 0.1 ppm, the highest in the modern instrumental record and in ice core records dating back 800 000 years. Combined, greenhouse gases and several halogenated gases contribute just over 3 W m−2 to radiative forcing and represent a nearly 43% increase since 1990. Carbon dioxide is responsible for about 65% of this radiative forcing. With a weak La Niña in early 2018 transitioning to a weak El Niño by the year's end, the global surface (land and ocean) temperature was the fourth highest on record, with only 2015 through 2017 being warmer. Several European countries reported record high annual temperatures. There were also more high, and fewer low, temperature extremes than in nearly all of the 68-year extremes record. Madagascar recorded a record daily temperature of 40.5°C in Morondava in March, while South Korea set its record high of 41.0°C in August in Hongcheon. Nawabshah, Pakistan, recorded its highest temperature of 50.2°C, which may be a new daily world record for April. Globally, the annual lower troposphere temperature was third to seventh highest, depending on the dataset analyzed. The lower stratospheric temperature was approximately fifth lowest. The 2018 Arctic land surface temperature was 1.2°C above the 1981-2010 average, tying for third highest in the 118-year record, following 2016 and 2017. June's Arctic snow cover extent was almost half of what it was 35 years ago. Across Greenland, however, regional summer temperatures were generally below or near average. Additionally, a satellite survey of 47 glaciers in Greenland indicated a net increase in area for the first time since records began in 1999. Increasing permafrost temperatures were reported at most observation sites in the Arctic, with the overall increase of 0.1°-0.2°C between 2017 and 2018 being comparable to the highest rate of warming ever observed in the region. On 17 March, Arctic sea ice extent marked the second smallest annual maximum in the 38-year record, larger than only 2017. The minimum extent in 2018 was reached on 19 September and again on 23 September, tying 2008 and 2010 for the sixth lowest extent on record. The 23 September date tied 1997 as the latest sea ice minimum date on record. First-year ice now dominates the ice cover, comprising 77% of the March 2018 ice pack compared to 55% during the 1980s. Because thinner, younger ice is more vulnerable to melting out in summer, this shift in sea ice age has contributed to the decreasing trend in minimum ice extent. Regionally, Bering Sea ice extent was at record lows for almost the entire 2017/18 ice season. For the Antarctic continent as a whole, 2018 was warmer than average. On the highest points of the Antarctic Plateau, the automatic weather station Relay (74°S) broke or tied six monthly temperature records throughout the year, with August breaking its record by nearly 8°C. However, cool conditions in the western Bellingshausen Sea and Amundsen Sea sector contributed to a low melt season overall for 2017/18. High SSTs contributed to low summer sea ice extent in the Ross and Weddell Seas in 2018, underpinning the second lowest Antarctic summer minimum sea ice extent on record. Despite conducive conditions for its formation, the ozone hole at its maximum extent in September was near the 2000-18 mean, likely due to an ongoing slow decline in stratospheric chlorine monoxide concentration. Across the oceans, globally averaged SST decreased slightly since the record El Niño year of 2016 but was still far above the climatological mean. On average, SST is increasing at a rate of 0.10° ± 0.01°C decade−1 since 1950. The warming appeared largest in the tropical Indian Ocean and smallest in the North Pacific. The deeper ocean continues to warm year after year. For the seventh consecutive year, global annual mean sea level became the highest in the 26-year record, rising to 81 mm above the 1993 average. As anticipated in a warming climate, the hydrological cycle over the ocean is accelerating: dry regions are becoming drier and wet regions rainier. Closer to the equator, 95 named tropical storms were observed during 2018, well above the 1981-2010 average of 82. Eleven tropical cyclones reached Saffir-Simpson scale Category 5 intensity. North Atlantic Major Hurricane Michael's landfall intensity of 140 kt was the fourth strongest for any continental U.S. hurricane landfall in the 168-year record. Michael caused more than 30 fatalities and $25 billion (U.S. dollars) in damages. In the western North Pacific, Super Typhoon Mangkhut led to 160 fatalities and $6 billion (U.S. dollars) in damages across the Philippines, Hong Kong, Macau, mainland China, Guam, and the Northern Mariana Islands. Tropical Storm Son-Tinh was responsible for 170 fatalities in Vietnam and Laos. Nearly all the islands of Micronesia experienced at least moderate impacts from various tropical cyclones. Across land, many areas around the globe received copious precipitation, notable at different time scales. Rodrigues and Réunion Island near southern Africa each reported their third wettest year on record. In Hawaii, 1262 mm precipitation at Waipā Gardens (Kauai) on 14-15 April set a new U.S. record for 24-h precipitation. In Brazil, the city of Belo Horizonte received nearly 75 mm of rain in just 20 minutes, nearly half its monthly average. Globally, fire activity during 2018 was the lowest since the start of the record in 1997, with a combined burned area of about 500 million hectares. This reinforced the long-term downward trend in fire emissions driven by changes in land use in frequently burning savannas. However, wildfires burned 3.5 million hectares across the United States, well above the 2000-10 average of 2.7 million hectares. Combined, U.S. wildfire damages for the 2017 and 2018 wildfire seasons exceeded $40 billion (U.S. dollars).
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- 2019
- Full Text
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22. Unconventional Charge Density Wave Order in the Pnictide Superconductor Ba(Ni_{1-x}Co_{x})_{2}As_{2}
- Author
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Sangjun, Lee, Gilberto, de la Peña, Stella X-L, Sun, Matteo, Mitrano, Yizhi, Fang, Hoyoung, Jang, Jun-Sik, Lee, Chris, Eckberg, Daniel, Campbell, John, Collini, Johnpierre, Paglione, F M F, de Groot, and Peter, Abbamonte
- Abstract
Ba(Ni_{1-x}Co_{x})_{2}As_{2} is a structural homologue of the pnictide high temperature superconductor, Ba(Fe_{1-x}Co_{x})_{2}As_{2}, in which the Fe atoms are replaced by Ni. Superconductivity is highly suppressed in this system, reaching a maximum T_{c}=2.3 K, compared to 24 K in its iron-based cousin, and the origin of this T_{c} suppression is not known. Using x-ray scattering, we show that Ba(Ni_{1-x}Co_{x})_{2}As_{2} exhibits a unidirectional charge density wave (CDW) at its triclinic phase transition. The CDW is incommensurate, exhibits a sizable lattice distortion, and is accompanied by the appearance of α Fermi surface pockets in photoemission [B. Zhou et al., Phys. Rev. B 83, 035110 (2011)PRBMDO1098-012110.1103/PhysRevB.83.035110], suggesting it forms by an unconventional mechanism. Co doping suppresses the CDW, paralleling the behavior of antiferromagnetism in iron-based superconductors. Our study demonstrates that pnictide superconductors can exhibit competing CDW order, which may be the origin of T_{c} suppression in this system.
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- 2018
23. State of the climate in 2017
- Author
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Abernethy, R., Ackerman, Steven A., Adler, R., Albanil Encarnación, Adelina, Aldeco, Laura S., Alfaro, Eric J., Aliaga-Nestares, Vannia, Allan, Richard P., Allan, Rob, Alves, Lincoln M., Amador, Jorge A., Anderson, John, Andreassen, L. M., Argüez, Anthony, Armitage, C., Arndt, Derek S., Avalos, Grinia, Azorin-Molina, César, Báez, Julián, Bardin, M. Yu, Barichivich, Jonathan, Baringer, Molly O., Barreira, Sandra, Baxter, Stephen, Beck, H. E., Becker, Andreas, Bedka, Kristopher M., Behe, Carolina, Bell, Gerald D., Bellouin, Nicolas, Belmont, M., Benedetti, Angela, Bernhard, G. H., Berrisford, Paul, Berry, David I., Bhatt, U. S., Bissolli, Peter, Bjerke, J., Blake, Eric S., Blenkinsop, Stephen, Blunden, Jessica, Bolmgren, K., Bosilovich, Michael G., Boucher, Olivier, Bouchon, Marilú, Box, J. E., Boyer, Tim, Braathen, Geir O., Bromwich, David H., Brown, R., Buehler, S., Bulygina, Olga N., Burgess, D., Calderón, Blanca, Camargo, Suzana J., Campbell, Ethan C., Campbell, Jayaka D., Cappelen, J., Carrea, Laura, Carter, Brendan R., Castro, Anabel, Chambers, Don P., Cheng, Lijing, Christiansen, Hanne H., Christy, John R., Chung, E. S., Clem, Kyle R., Coelho, Caio A.S., Coldewey-Egbers, Melanie, Colwell, Steve, Cooper, Owen R., Copland, L., Costanza, Carol, Covey, Curt, Coy, Lawrence, Cronin, T., Crouch, Jake, Cruzado, Luis, Daniel, Raychelle, Davis, Sean M., Davletshin, S. G., De Eyto, Elvira, De Jeu, Richard A.M., De La Cour, Jacqueline L., De Laat, Jos, De Gasperi, Curtis L., Degenstein, Doug, Deline, P., Demircan, Mesut, Derksen, C., Dewitte, Boris, Dhurmea, R., Di Girolamo, Larry, Diamond, Howard J., Dickerson, C., Dlugokencky, Ed J., Dohan, Kathleen, Dokulil, Martin T., Dolman, A. Johannes, Domingues, Catia M., Domingues, Ricardo, Donat, Markus G., Dong, Shenfu, Dorigo, Wouter A., Drozdov, D. S., Dunn, Robert J.H., Durre, Imke, Dutton, Geoff S., Eakin, C. Mark, El Kharrim, M., Elkins, James W., Epstein, H. E., Espinoza, Jhan C., Famiglietti, James S., Farmer, J., Farrell, S., Fauchald, P., Fausto, R. S., Feely, Richard A., Feng, Z., Fenimore, Chris, Fettweis, X., Fioletov, Vitali E., Flemming, Johannes, Fogt, Ryan L., Folland, Chris, Forbes, B. C., Foster, Michael J., Francis, S. D., Franz, Bryan A., Frey, Richard A., Frith, Stacey M., Froidevaux, Lucien, Ganter, Catherine, Geiger, Erick F., Gerland, S., Gilson, John, Gobron, Nadine, Goldenberg, Stanley B., Gomez, Andrea M., Goni, Gustavo, Grooß, Jens Uwe, Gruber, Alexander, Guard, Charles P., Gugliemin, Mario, Gupta, S. K., Gutiérrez, Dimitri, Haas, C., Hagos, S., Hahn, Sebastian, Haimberger, Leo, Hall, Brad D., Halpert, Michael S., Hamlington, Benjamin D., Hanna, E., Hansen, K., Hanssen-Bauer, L., Harris, Ian, Hartfield, Gail, Heidinger, Andrew K., Heim, Richard R., Helfrich, S., Hemming, D. L., Hendricks, S., Hernández, Rafael, Hernández, Sosa Marieta, Heron, Scott F., Heuzé, C., Hidalgo, Hugo G., Ho, Shu Peng, Hobbs, William R., Horstkotte, T., Huang, Boyin, Hubert, Daan, Hueuzé, Céline, Hurst, Dale F., Ialongo, Iolanda, Ibrahim, M. M., Ijampy, J. A., Inness, Antje, Isaac, Victor, Isaksen, K., Ishii, Masayoshi, Jacobs, Stephanie J., Jeffries, Martin O., Jevrejeva, Svetlana, Jiménez, C., Jin, Xiangze, John, Viju, Johns, William E., Johnsen, Bjørn, Johnson, Bryan, Johnson, Gregory C., Johnson, Kenneth S., Jones, Philip D., Jumaux, Guillaume, Kabidi, Khadija, Kaiser, J. W., Karaköylü, Erdem M., Kato, Seiji, Kazemi, A., Keller, Linda M., Kennedy, John, Kerr, Kenneth, Khan, M. S., Kholodov, A. L., Khoshkam, Mahbobeh, Killick, Rachel, Kim, Hyungjun, Kim, S. J., Klotzbach, Philip J., Knaff, John A., Kohler, J., Korhonen, Johanna, Korshunova, Natalia N., Kramarova, Natalya, Kratz, D. P., Kruger, Andries, Kruk, Michael C., Krumpen, T., Ladd, C., Lakatos, Mónika, Lakkala, Kaisa, Lander, Mark A., Landschützer, Peter, Landsea, Chris W., Lankhorst, Matthias, Lavado-Casimiro, Waldo, Lazzara, Matthew A., Lee, S. E., Lee, T. C., Leuliette, Eric, L'Heureux, Michelle, Li, Tim, Lieser, Jan L., Lin, I. I., Mears, Carl A., Liu, Gang, Li, Bailing, Liu, Hongxing, Locarnini, Ricardo, Loeb, Norman G., Long, Craig S., López, Luis A., Lorrey, Andrew M., Loyola, Diego, Lumpkin, Rick, Luo, Jing Jia, Luojus, K., Luthcke, S., Macias-Fauria, M., Malkova, G. V., Manney, Gloria L., Marcellin, Vernie, Marchenko, S. S., Marengo, José A., Marín, Dora, Marra, John J., Marszelewski, Wlodzimierz, Martens, B., Martin, A., Martínez, Alejandra G., Martínez-Güingla, Rodney, Martínez-Sánchez, Odalys, Marsh, Benjamin L., Lyman, John M., Massom, Robert A., May, Linda, Mayer, Michael, Mazloff, Matthew, McBride, Charlotte, McCabe, M. F., McCarthy, Mark, Meier, W., Meijers, Andrew J.S., Mekonnen, Ademe, Mengistu Tsidu, G., Menzel, W. Paul, Merchant, Christopher J., Meredith, Michael P., Merrifield, Mark A., Miller, Ben, Miralles, Diego G., Mitchum, Gary T., Mitro, Sukarni, Moat, Ben, Mochizuki, Y., Monselesan, Didier, Montzka, Stephen A., Mora, Natalie, Morice, Colin, Mosquera-Vásquez, Kobi, Mostafa, Awatif E., Mote, T., Mudryk, L., Mühle, Jens, Mullan, A. Brett, Müller, Rolf, Myneni, R., Nash, Eric R., Nerem, R. Steven, Newman, L., Newman, Paul A., Nielsen-Gammon, John W., Nieto, Juan José, Noetzli, Jeannette, Noll, Ben E., O'Neel, S., Osborn, Tim J., Osborne, Emily, Overland, J., Oyunjargal, Lamjav, Park, T., Pasch, Richard J., Pascual-Ramírez, Reynaldo, Pastor Saavedra, Maria Asuncion, Paterson, Andrew M., Paulik, Christoph, Pearce, Petra R., Peltier, Alexandre, Pelto, Mauri S., Peng, Liang, Perkins-Kirkpatrick, Sarah E., Perovich, Don, Petropavlovskikh, Irina, Pezza, Alexandre B., Phillips, C., Phillips, David, Phoenix, G., Pinty, Bernard, Pinzon, J., Po-Chedley, S., Polashenski, C., Purkey, Sarah G., Quispe, Nelson, Rajeevan, Madhavan, Rakotoarimalala, C., Rayner, Darren, Raynolds, M. K., Reagan, James, Reid, Phillip, Reimer, Christoph, Rémy, Samuel, Revadekar, Jayashree V., Richardson, A. D., Richter-Menge, Jacqueline, Ricker, R., Rimmer, Alon, Robinson, David A., Rodell, Matthew, Rodriguez Camino, Ernesto, Romanovsky, Vladimir E., Ronchail, Josyane, Rosenlof, Karen H., Rösner, Benjamin, Roth, Chris, Roth, David Mark, Rusak, James A., Rutishäuser, T., Sallée, Jean Bapiste, Sánchez-Lugo, Ahira, Santee, Michelle L., Sasgen, L., Sawaengphokhai, P., Sayad, T. A., Sayouri, Amal, Scambos, Ted A., Scanlon, T., Schenzinger, Verena, Schladow, S. Geoffrey, Schmid, Claudia, Schmid, Martin, Schreck, Carl J., Selkirk, H. B., Send, Uwe, Sensoy, Serhat, Sharp, M., Shi, Lei, Shiklomanov, Nikolai I., Shimaraeva, Svetlana V., Siegel, David A., Silow, Eugene, Sima, Fatou, Simmons, Adrian J., Skirving, William J., Smeed, David A., Smeets, C. J.P.P., Smith, Adam, Smith, Sharon L., Soden, B., Sofieva, Viktoria, Sparks, T. H., Spence, Jacqueline M., Spillane, Sandra, Srivastava, A. K., Stackhouse, Paul W., Stammerjohn, Sharon, Stanitski, Diane M., Steinbrecht, Wolfgang, Stella, José L., Stengel, M., Stephenson, Kimberly, Stephenson, Tannecia S., Strahan, Susan, Streletskiy, Dimitri A., Strong, Alan E., Sun-Mack, Sunny, Sutton, Adrienne J., Swart, Sebastiaan, Sweet, William, Takahashi, Kenneth S., Tamar, Gerard, Taylor, Michael A., Tedesco, M., Thackeray, S. J., Thoman, R. L., Thompson, Philip, Thomson, L., Thorsteinsson, T., Timbal, Bertrand, Timmermans, M. L., TImofeyev, Maxim A., Tirak, Kyle V., Tobin, Skie, Togawa, H., Tømmervik, H., Tourpali, Kleareti, Trachte, Katja, Trewin, Blair C., Triñanes, Joaquin A., Trotman, Adrian R., Tschudi, M., Tucker, C. J., Tye, Mari R., Van As, D., Van De Wal, R. S.W., Van Der Ronald, J. A., Van Der Schalie, Robin, Van Der Schrier, Gerard, Van Der Werf, Guido R., Van Meerbeeck, Cedric J., Velden, Christopher S., Velicogna, I., Verburg, Piet, Vickers, H., Vincent, Lucie A., Vömel, Holger, Vose, Russell S., Wagner, Wolfgang, Walker, D. A., Walsh, J., Wang, Bin, Wang, Junhong, Wang, Lei, Wang, M., Wang, Ray, Wang, Sheng Hung, Wanninkhof, Rik, Watanabe, Shohei, Weber, Mark, Webster, M., Weller, Robert A., Westberry, Toby K., Weyhenmeyer, Gesa A., Whitewood, Robert, Widlansky, Matthew J., Wiese, David N., Wijffels, Susan E., Wilber, Anne C., Wild, Jeanette D., Willett, Kate M., Willis, Josh K., Wolken, G., Wong, Takmeng, Wood, E. F., Wood, K., Woolway, R. Iestyn, Wouters, B., Xue, Yan, Yin, Xungang, Yoon, Huang, York, A., Yu, Lisan, Zambrano, Eduardo, Zhang, Huai Min, Zhang, Peiqun, Zhao, Guanguo, Zhao, Lin, Zhu, Zhiwei, Ziel, R., Ziemke, Jerry R., Ziese, Markus G., Griffin, Jessicca, Hammer, Gregory, Love-Brotak, S. Elizabeth, Misch, Deborah J., Riddle, Deborah B., Slagle, Mary, Sprain, Mara, Veasey, Sara W., McVicar, Tim R., Sub Dynamics Meteorology, Sub Soft Condensed Matter, LS Religiewetenschap, Sub Atmospheric physics and chemistry, Zonder bezoldiging NED, LS Taalverwerving, Leerstoel Tubergen, Afd Chemical Biology and Drug Discovery, Hafd Faculteitsbureau GW, Afd Pharmacology, Dep IRAS, Marine and Atmospheric Research, and OFR - Religious Studies
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Atmospheric Science - Abstract
In 2017, the dominant greenhouse gases released into Earth's atmosphere-carbon dioxide, methane, and nitrous oxide-reached new record highs. The annual global average carbon dioxide concentration at Earth's surface for 2017 was 405.0 ± 0.1 ppm, 2.2 ppm greater than for 2016 and the highest in the modern atmospheric measurement record and in ice core records dating back as far as 800 000 years. The global growth rate of CO2 has nearly quadrupled since the early 1960s. With ENSO-neutral conditions present in the central and eastern equatorial Pacific Ocean during most of the year and weak La Niña conditions notable at the start and end, the global temperature across land and ocean surfaces ranked as the second or third highest, depending on the dataset, since records began in the mid-to-late 1800s. Notably, it was the warmest non-El Niño year in the instrumental record. Above Earth's surface, the annual lower tropospheric temperature was also either second or third highest according to all datasets analyzed. The lower stratospheric temperature was about 0.2°C higher than the record cold temperature of 2016 according to most of the in situ and satellite datasets. Several countries, including Argentina, Uruguay, Spain, and Bulgaria, reported record high annual temperatures. Mexico broke its annual record for the fourth consecutive year. On 27 January, the temperature reached 43.4°C at Puerto Madryn, Argentina-the highest temperature recorded so far south (43°S) anywhere in the world. On 28 May in Turbat, western Pakistan, the high of 53.5°C tied Pakistan's all-time highest temperature and became the world-record highest temperature for May. In the Arctic, the 2017 land surface temperature was 1.6°C above the 1981-2010 average, the second highest since the record began in 1900, behind only 2016. The five highest annual Arctic temperatures have all occurred since 2007. Exceptionally high temperatures were observed in the permafrost across the Arctic, with record values reported in much of Alaska and northwestern Canada. In August, high sea surface temperature (SST) records were broken for the Chukchi Sea, with some regions as warm as +11°C, or 3° to 4°C warmer than the longterm mean (1982-present). According to paleoclimate studies, today's abnormally warm Arctic air and SSTs have not been observed in the last 2000 years. The increasing temperatures have led to decreasing Arctic sea ice extent and thickness. On 7 March, sea ice extent at the end of the growth season saw its lowest maximum in the 37-year satellite record, covering 8% less area than the 1981-2010 average. The Arctic sea ice minimum on 13 September was the eighth lowest on record and covered 25% less area than the long-term mean. Preliminary data indicate that glaciers across the world lost mass for the 38th consecutive year on record; the declines are remarkably consistent from region to region. Cumulatively since 1980, this loss is equivalent to slicing 22 meters off the top of the average glacier. Antarctic sea ice extent remained below average for all of 2017, with record lows during the first four months. Over the continent, the austral summer seasonal melt extent and melt index were the second highest since 2005, mostly due to strong positive anomalies of air temperature over most of the West Antarctic coast. In contrast, the East Antarctic Plateau saw record low mean temperatures in March. The year was also distinguished by the second smallest Antarctic ozone hole observed since 1988. Across the global oceans, the overall long-term SST warming trend remained strong. Although SST cooled slightly from 2016 to 2017, the last three years produced the three highest annual values observed; these high anomalies have been associated with widespread coral bleaching. The most recent global coral bleaching lasted three full years, June 2014 to May 2017, and was the longest, most widespread, and almost certainly most destructive such event on record. Global integrals of 0-700-m and 0-2000-m ocean heat content reached record highs in 2017, and global mean sea level during the year became the highest annual average in the 25-year satellite altimetry record, rising to 77 mm above the 1993 average. In the tropics, 2017 saw 85 named tropical storms, slightly above the 1981-2010 average of 82. The North Atlantic basin was the only basin that featured an above-normal season, its seventh most active in the 164-year record. Three hurricanes in the basin were especially notable. Harvey produced record rainfall totals in areas of Texas and Louisiana, including a storm total of 1538.7 mm near Beaumont, Texas, which far exceeds the previous known U.S. tropical cyclone record of 1320.8 mm. Irma was the strongest tropical cyclone globally in 2017 and the strongest Atlantic hurricane outside of the Gulf of Mexico and Caribbean on record with maximum winds of 295 km h-1. Maria caused catastrophic destruction across the Caribbean Islands, including devastating wind damage and flooding across Puerto Rico. Elsewhere, the western North Pacific, South Indian, and Australian basins were all particularly quiet. Precipitation over global land areas in 2017 was clearly above the long-term average. Among noteworthy regional precipitation records in 2017, Russia reported its second wettest year on record (after 2013) and Norway experienced its sixth wettest year since records began in 1900. Across India, heavy rain and flood-related incidents during the monsoon season claimed around 800 lives. In August and September, above-normal precipitation triggered the most devastating floods in more than a decade in the Venezuelan states of Bolívar and Delta Amacuro. In Nigeria, heavy rain during August and September caused the Niger and Benue Rivers to overflow, bringing floods that displaced more than 100 000 people. Global fire activity was the lowest since at least 2003; however, high activity occurred in parts of North America, South America, and Europe, with an unusually long season in Spain and Portugal, which had their second and third driest years on record, respectively. Devastating fires impacted British Columbia, destroying 1.2 million hectares of timber, bush, and grassland, due in part to the region's driest summer on record. In the United States, an extreme western wildfire season burned over 4 million hectares; the total costs of $18 billion tripled the previous U.S. annual wildfire cost record set in 1991.
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- 2018
24. Unconventional Charge Density Wave Order in the Pnictide Superconductor Ba(Ni$_{1-x}$Co$_x$)$_2$As$_2$
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Lee, Sangjun, de la Pena, Gilberto, Sun, Stella X. -L., Mitrano, Matteo, Fang, Yizhi, Jang, Hoyoung, Lee, Jun-Sik, Eckberg, Chris, Campbell, Daniel, Collini, John, Paglione, Johnpierre, de Groot, F. M. F., and Abbamonte, Peter
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Condensed Matter - Strongly Correlated Electrons ,Strongly Correlated Electrons (cond-mat.str-el) ,Condensed Matter::Superconductivity ,FOS: Physical sciences ,Condensed Matter::Strongly Correlated Electrons - Abstract
Ba(Ni$_{1-x}$Co$_x$)$_2$As$_2$ is a structural homologue of the pnictide high temperature superconductor, Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$, in which the Fe atoms are replaced by Ni. Superconductivity is highly suppressed in this system, reaching a maximum $T_c$ = 2.3 K, compared to 24 K in its iron-based cousin, and the origin of this $T_c$ suppression is not known. Using x-ray scattering, we show that Ba(Ni$_{1-x}$Co$_x$)$_2$As$_2$ exhibits a unidirectional charge density wave (CDW) at its triclinic phase transition. The CDW is incommensurate, exhibits a sizable lattice distortion, and is accompanied by the appearance of $\alpha$ Fermi surface pockets in photoemission [B. Zhou et al., Phys. Rev. B 83, 035110 (2011)], suggesting it forms by an unconventional mechanism. Co doping suppresses the CDW, paralleling the behavior of antiferromagnetism in iron-based superconductors. Our study demonstrates that pnictide superconductors can exhibit competing CDW order, which may be the origin of $T_c$ suppression in this system.
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- 2018
25. State of the climate in 2016
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Aaron-Morrison, A. P., Ackerman, S. A., Adams, N. G., Adler, R. F., Albanil, A., Alfaro, E. J., Allan, R., Alves, L. M., Amador, J. A., Andreassen, L. M., Arendt, A., Arévalo, J., Arndt, D. S., Arzhanova, N. M., Aschan, M. M., Azorin-Molina, C., Banzon, V., Bardin, M. U., Barichivich, J., Baringer, M. O., Barreira, S., Baxter, S., Bazo, J., Becker, A., Bedka, K. M., Behrenfeld, M. J., Bell, G. D., Belmont, M., Benedetti, A., Bernhard, G., Berrisford, P., Berry, D. I., Bettolli, M. L., Bhatt, U. S., Bidegain, M., Bill, B. D., Billheimer, S., Bissolli, P., Blake, E. S., Blunden, J., Bosilovich, M. G., Boucher, O., Boudet, D., Box, J. E., Boyer, T., Braathen, G. O., Bromwich, D. H., Brown, R., Bulygina, O. N., Burgess, D., Calderón, B., Camargo, S. J., Campbell, J. D., Cappelen, J., Carrasco, G., Carter, B. R., Chambers, D. P., Chandler, E., Christiansen, H. H., Christy, J. R., Chung, D., Chung, E. S., Cinque, K., Clem, K. R., Coelho, C. A., Cogley, J. G., Coldewey-Egbers, M., Colwell, S., Cooper, O. R., Copland, L., Cosca, C. E., Cross, J. N., Crotwell, M. J., Crouch, J., Davis, S. M., Eyto, E., Jeu, R. A. M., Laat, J., Degasperi, C. L., Degenstein, D., Demircan, M., Derksen, C., Destin, D., Di Girolamo, L., Di Giuseppe, F., Diamond, H. J., Dlugokencky, E. J., Dohan, K., Dokulil, M. T., Dolgov, A. V., Dolman, A. J., Domingues, C. M., Donat, M. G., Dong, S., Dorigo, W. A., Dortch, Q., Doucette, G., Drozdov, D. S., Ducklow, H., Dunn, R. J. H., Durán-Quesada, A. M., Dutton, G. S., Ebrahim, A., Elkharrim, M., Elkins, J. W., Espinoza, J. C., Etienne-Leblanc, S., Evans, T. E., Famiglietti, J. S., Farrell, S., Fateh, S., Fausto, R. S., Fedaeff, N., Feely, R. A., Feng, Z., Fenimore, C., Fettweis, X., Fioletov, V. E., Flemming, J., Fogarty, C. T., Fogt, R. L., Folland, C., Fonseca, C., Fossheim, M., Foster, M. J., Fountain, A., Francis, S. D., Franz, B. A., Frey, R. A., Frith, S. M., Froidevaux, L., Ganter, C., Garzoli, S., Gerland, S., Gobron, N., Goldenberg, S. B., Gomez, R. S., Goni, G., Goto, A., Grooß, J. U., Gruber, A., Guard, C. C., Gugliemin, M., Gupta, S. K., Gutiérrez, J. M., Hagos, S., Hahn, S., Haimberger, L., Hakkarainen, J., Hall, B. D., Halpert, M. S., Hamlington, B. D., Hanna, E., Hansen, K., Hanssen-Bauer, I., Harris, I., Heidinger, A. K., Heikkilä, A., Heil, A., Heim, R. R., Hendricks, S., Hernández, M., Hidalgo, H. G., Hilburn, K., Ho, S. P. B., Holmes, R. M., Hu, Z. Z., Huang, B., Huelsing, H. K., Huffman, G. J., Hughes, C., Hurst, D. F., Ialongo, I., Ijampy, J. A., Ingvaldsen, R. B., Inness, A., Isaksen, K., Ishii, M., Jevrejeva, S., Jiménez, C., Jin, X., Johannesen, E., John, V., Johnsen, B., Johnson, B., Johnson, G. C., Jones, P. D., Joseph, A. C., Jumaux, G., Kabidi, K., Kaiser, J. W., Kato, S., Kazemi, A., Keller, L. M., Kendon, M., Kennedy, J., Kerr, K., Kholodov, A. L., Khoshkam, M., Killick, R., Kim, H., Kim, S. J., Kimberlain, T. B., Klotzbach, P. J., Knaff, J. A., Kobayashi, S., Kohler, J., Korhonen, J., Korshunova, N. N., Kovacs, K. M., Kramarova, N., Kratz, D. P., Kruger, A., Kruk, M. C., Kudela, R., Kumar, A., Lakatos, M., Lakkala, K., Lander, M. A., Landsea, C. W., Lankhorst, M., Lantz, K., Lazzara, M. A., Lemons, P., Leuliette, E., L’heureux, M., Lieser, J. L., Lin, I. I., Liu, H., Liu, Y., Locarnini, R., Loeb, N. G., Lo Monaco, C., Long, C. S., López Álvarez, L. A., Lorrey, A. M., Loyola, D., Lumpkin, R., Luo, J. J., Luojus, K., Lydersen, C., Lyman, J. M., Maberly, S. C., Maddux, B. C., Malheiros Ramos, A., Malkova, G. V., Manney, G., Marcellin, V., Marchenko, S. S., Marengo, J. A., Marra, J. J., Marszelewski, W., Martens, B., Martínez-Güingla, R., Massom, R. A., Mata, M. M., Mathis, J. T., May, L., Mayer, M., Mazloff, M., Mcbride, C., Mccabe, M. F., Mccarthy, M., Mcclelland, J. W., Mcgree, S., Mcvicar, T. R., Mears, C. A., Meier, W., Meinen, C. S., Mekonnen, A., Menéndez, M., Mengistu Tsidu, G., Menzel, W. P., Merchant, C. J., Meredith, M. P., Merrifield, M. A., Metzl, N., Minnis, P., Miralles, D. G., Mistelbauer, T., Mitchum, G. T., Monselesan, D., Monteiro, P., Montzka, S. A., Morice, C., Mote, T., Mudryk, L., Mühle, J., Mullan, A. B., Nash, E. R., Naveira-Garabato, A. C., Nerem, R. S., Newman, P. A., Nieto, J. J., Noetzli, J., O’neel, S., Osborn, T. J., Overland, J., Oyunjargal, L., Parinussa, R. M., Park, E. H., Parker, D., Parrington, M., Parsons, A. R., Pasch, R. J., Pascual-Ramírez, R., Paterson, A. M., Paulik, C., Pearce, P. R., Pelto, M. S., Peng, L., Perkins-Kirkpatrick, S. E., Perovich, D., Petropavlovskikh, I., Pezza, A. B., Phillips, D., Pinty, B., Pitts, M. C., Pons, M. R., Porter, A. O., Primicerio, R., Proshutinsky, A., Quegan, S., Quintana, J., Rahimzadeh, F., Rajeevan, M., Randriamarolaza, L., Razuvaev, V. N., Reagan, J., Reid, P., Reimer, C., Rémy, S., Renwick, J. A., Revadekar, J. V., Richter-Menge, J., Riffler, M., Rimmer, A., Rintoul, S., Robinson, D. A., Rodell, M., Rodríguez Solís, J. L., Romanovsky, V. E., Ronchail, J., Rosenlof, K. H., Roth, C., Rusak, J. A., Sabine, C. L., Sallée, J. B., Sánchez-Lugo, A., Santee, M. L., Sawaengphokhai, P., Sayouri, A., Scambos, T. A., Schemm, J., Schladow, S. G., Schmid, C., Schmid, M., Schmidtko, S., Schreck, C. J., Selkirk, H. B., Send, U., Sensoy, S., Setzer, A., Sharp, M., Shaw, A., Shi, L., Shiklomanov, A. I., Shiklomanov, N. I., Siegel, D. A., Signorini, S. R., Sima, F., Simmons, A. J., Smeets, C. J. P. P., Smith, S. L., Spence, J. M., Srivastava, A. K., Stackhouse, P. W., Stammerjohn, S., Steinbrecht, W., Stella, J. L., Stengel, M., Stennett-Brown, R., Stephenson, T. S., Strahan, S., Streletskiy, D. A., Sun-Mack, S., Swart, S., Sweet, W., Talley, L. D., Tamar, G., Tank, S. E., Taylor, M. A., Tedesco, M., Teubner, K., Thoman, R. L., Thompson, P., Thomson, L., Timmermans, M. L., Maxim Timofeyev, Tirnanes, J. A., Tobin, S., Trachte, K., Trainer, V. L., Tretiakov, M., Trewin, B. C., Trotman, A. R., Tschudi, M., As, D., Wal, R. S. W., A, R. J., Schalie, R., Schrier, G., Werf, G. R., Meerbeeck, C. J., Velicogna, I., Verburg, P., Vigneswaran, B., Vincent, L. A., Volkov, D., Vose, R. S., Wagner, W., Wåhlin, A., Wahr, J., Walsh, J., Wang, C., Wang, J., Wang, L., Wang, M., Wang, S. H., Wanninkhof, R., Watanabe, S., Weber, M., Weller, R. A., Weyhenmeyer, G. A., Whitewood, R., Wijffels, S. E., Wilber, A. C., Wild, J. D., Willett, K. M., Williams, M. J. M., Willie, S., Wolken, G., Wong, T., Wood, E. F., Woolway, R. I., Wouters, B., Xue, Y., Yamada, R., Yim, S. Y., Yin, X., Young, S. H., Yu, L., Zahid, H., Zambrano, E., Zhang, P., Zhao, G., Zhou, L., Ziemke, J. R., Love-Brotak, S. E., Gilbert, K., Maycock, T., Osborne, S., Sprain, M., Veasey, S. W., Ambrose, B. J., Griffin, J., Misch, D. J., Riddle, D. B., Young, T., Macias Fauria, M, Blunden, J, Arndt, D, Earth and Climate, Faculty of Earth and Life Sciences, Clinical Developmental Psychology, Climate Change and Landscape Dynamics, and Molecular Cell Physiology
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Meteor (satellite) ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,0208 environmental biotechnology ,02 engineering and technology ,01 natural sciences ,020801 environmental engineering ,Geography ,13. Climate action ,Climatology ,SDG 13 - Climate Action ,SDG 14 - Life Below Water ,0105 earth and related environmental sciences - Abstract
In 2016, the dominant greenhouse gases released into Earth's atmosphere-carbon dioxide, methane, and nitrous oxide-continued to increase and reach new record highs. The 3.5 +/- 0.1 ppm rise in global annual mean carbon dioxide from 2015 to 2016 was the largest annual increase observed in the 58-year measurement record. The annual global average carbon dioxide concentration at Earth's surface surpassed 400 ppm (402.9 +/- 0.1 ppm) for the first time in the modern atmospheric measurement record and in ice core records dating back as far as 800000 years. One of the strongest El Nino events since at least 1950 dissipated in spring, and a weak La Nina evolved later in the year. Owing at least in part to the combination of El Nino conditions early in the year and a long-term upward trend, Earth's surface observed record warmth for a third consecutive year, albeit by a much slimmer margin than by which that record was set in 2015. Above Earth's surface, the annual lower troposphere temperature was record high according to all datasets analyzed, while the lower stratospheric temperature was record low according to most of the in situ and satellite datasets. Several countries, including Mexico and India, reported record high annual temperatures while many others observed near-record highs. A week-long heat wave at the end of April over the northern and eastern Indian peninsula, with temperatures surpassing 44 degrees C, contributed to a water crisis for 330 million people and to 300 fatalities. In the Arctic the 2016 land surface temperature was 2.0 degrees C above the 1981-2010 average, breaking the previous record of 2007, 2011, and 2015 by 0.8 degrees C, representing a 3.5 degrees C increase since the record began in 1900. The increasing temperatures have led to decreasing Arctic sea ice extent and thickness. On 24 March, the sea ice extent at the end of the growth season saw its lowest maximum in the 37-year satellite record, tying with 2015 at 7.2% below the 1981-2010 average. The September 2016 Arctic sea ice minimum extent tied with 2007 for the second lowest value on record, 33% lower than the 1981-2010 average. Arctic sea ice cover remains relatively young and thin, making it vulnerable to continued extensive melt. The mass of the Greenland Ice Sheet, which has the capacity to contribute similar to 7 m to sea level rise, reached a record low value. The onset of its surface melt was the second earliest, after 2012, in the 37-year satellite record. Sea surface temperature was record high at the global scale, surpassing the previous record of 2015 by about 0.01 degrees C. The global sea surface temperature trend for the 21st century-to-date of +0.162 degrees C decade(-1) is much higher than the longer term 1950-2016 trend of +0.100 degrees C decade(-1). Global annual mean sea level also reached a new record high, marking the sixth consecutive year of increase. Global annual ocean heat content saw a slight drop compared to the record high in 2015. Alpine glacier retreat continued around the globe, and preliminary data indicate that 2016 is the 37th consecutive year of negative annual mass balance. Across the Northern Hemisphere, snow cover for each month from February to June was among its four least extensive in the 47-year satellite record. Continuing a pattern below the surface, record high temperatures at 20-m depth were measured at all permafrost observatories on the North Slope of Alaska and at the Canadian observatory on northernmost Ellesmere Island. In the Antarctic, record low monthly surface pressures were broken at many stations, with the southern annular mode setting record high index values in March and June. Monthly high surface pressure records for August and November were set at several stations. During this period, record low daily and monthly sea ice extents were observed, with the November mean sea ice extent more than 5 standard deviations below the 1981-2010 average. These record low sea ice values contrast sharply with the record high values observed during 2012-14. Over the region, springtime Antarctic stratospheric ozone depletion was less severe relative to the 1991-2006 average, but ozone levels were still low compared to pre-1990 levels. Closer to the equator, 93 named tropical storms were observed during 2016, above the 1981-2010 average of 82, but fewer than the 101 storms recorded in 2015. Three basins-the North Atlantic, and eastern and western North Pacific-experienced above-normal activity in 2016. The Australian basin recorded its least active season since the beginning of the satellite era in 1970. Overall, four tropical cyclones reached the Saffir-Simpson category 5 intensity level. The strong El Nino at the beginning of the year that transitioned to a weak La Nina contributed to enhanced precipitation variability around the world. Wet conditions were observed throughout the year across southern South America, causing repeated heavy flooding in Argentina, Paraguay, and Uruguay. Wetter-than-usual conditions were also observed for eastern Europe and central Asia, alleviating the drought conditions of 2014 and 2015 in southern Russia. In the United States, California had its first wetter-than-average year since 2012, after being plagued by drought for several years. Even so, the area covered by drought in 2016 at the global scale was among the largest in the post-1950 record. For each month, at least 12% of land surfaces experienced severe drought conditions or worse, the longest such stretch in the record. In northeastern Brazil, drought conditions were observed for the fifth consecutive year, making this the longest drought on record in the region. Dry conditions were also observed in western Bolivia and Peru; it was Bolivia's worst drought in the past 25 years. In May, with abnormally warm and dry conditions already prevailing over western Canada for about a year, the human-induced Fort McMurray wildfire burned nearly 590000 hectares and became the costliest disaster in Canadian history, with $3 billion (U.S. dollars) in insured losses.
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- 2017
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26. Molecular characterization of Neisseria gonorrhoeae on non-cultured specimens from multiple anatomic sites
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Carannante, A., Ghisetti, V., Conte, I. D., Gregori, G., Stella, M. L., Vacca, P., Simonetta, D. R., and Stefanelli, P.
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Adult ,Male ,drug resistance ,sequence analysis ,typing ,Microbial Sensitivity Tests ,Sequence Analysis, DNA ,dna ,Neisseria gonorrhoeae ,ng-mast ,Anti-Bacterial Agents ,Gonorrhea ,Young Adult ,neisseria gonorrhoeae ,non-cultured specimens ,adult ,anti-bacterial agents ,drug resistance, bacterial ,female ,genitalia ,gonorrhea ,humans ,male ,microbial sensitivity tests ,nucleic acid amplification techniques ,sequence analysis, dna ,young adult ,Drug Resistance, Bacterial ,Humans ,bacterial ,Female ,Genitalia ,Nucleic Acid Amplification Techniques - Abstract
The aim of this study was to molecularly characterize Neisseria gonorrhoeae on non-cultured specimens collected from multiple anatomic sites. N. gonorrhoeae multiantigen sequence typing (NG-MAST) together with the gene sequence analysis of antimicrobial resistance (AMR) target genes were used.Seventeen genital and extra-genital samples from eight patients (7 were men who have sex with men, MSM, and 1 women who have sex with men, WSM) with gonorrhoea symptoms were analyzed. For 7, of the 8 patients, conventional culture method has been used to identify gonorrhoea. All the samples were tested with the rapid molecular method CEPHEID. Amplification and sequencing of porB and tbpB, to identify the Sequence Type (ST) by NG-MAST, and penA, mtrR, porB1b, ponA genes were also performed. Antimicrobial susceptibility by Etest, for the available culture positive samples, was carried out.For 7 patients the ST was obtained and for 6 the complete sequence analysis of the AMR target genes was also defined. For the majority of them, samples collected from multiple sites (oropharynx, rectum, vaginal and urethra) confirm the presence of the same gonorrhoea strain. In particular, for 5 patients the same STs and changes in the AMR target genes were identified.Molecular characterization on non-cultured or culture negative specimens for gonorrhoea can successfully be applied directly to genital and extra-genital samples. Thus permit to identify the presence of the same strain in patients with gonorrhoea infection in multiple anatomic sites and to predict the antimicrobial susceptibility pattern.
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- 2017
27. State of the Climate in 2016: Southern South America
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Bidegain, Mario, Stella, Jose L., Bettolli, Maria Laura, and Quintana, Juan
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purl.org/becyt/ford/1 [https] ,purl.org/becyt/ford/1.5 [https] ,PRECIPITATION ,SOUTH AMERICA ,Meteorología y Ciencias Atmosféricas ,TEMPERATURE ,CIENCIAS NATURALES Y EXACTAS ,Ciencias de la Tierra y relacionadas con el Medio Ambiente - Abstract
Fil: Bidegain, Mario. Instituto Uruguayo de Meteorologia; Uruguay Fil: Stella, Jose L.. Ministerio de Defensa. Secretaria de Planeamiento. Servicio Meteorológico Nacional; Argentina Fil: Bettolli, Maria Laura. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Quintana, Juan. Dirección Meteorológica de Chile; Chile
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- 2017
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28. New nitric oxide (NO) nightglow measurements with SPICAM/MEx as a tracer of Mars upper atmosphere circulation and comparison with LMD-MGCM model prediction: Evidence for asymmetric hemispheres
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Jean-Loup Bertaux, Kimberly Strong, Marie-Ève Gagné, Francisco Gonzalez-Galindo, Franck Montmessin, and Stella M. L. Melo
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Martian ,010504 meteorology & atmospheric sciences ,Airglow ,Mars Exploration Program ,Atmosphere of Mars ,Atmospheric sciences ,01 natural sciences ,Atmosphere ,Mars general circulation model ,Geophysics ,13. Climate action ,Space and Planetary Science ,Geochemistry and Petrology ,0103 physical sciences ,Earth and Planetary Sciences (miscellaneous) ,Thermosphere ,Spectroscopy ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences - Abstract
[1] We report observations of NO nightglow with the Spectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars (SPICAM) experiment on board the Mars Express (MEx) spacecraft. NO molecules emit an ultraviolet photon when N and O atoms (produced at high altitude in the thermosphere) recombine. Therefore, this emission is a tracer of the atmospheric dynamics in the lower thermosphere where O and N atoms are produced, and below, in the altitude region 50–100 km where the emission is detected. A new retrieval method has been developed to analyze the measurements from this instrument in the stellar occultation mode without slit and retrieve the absolute brightness of the emission. We present the results from the processing of more than 2000 orbits, providing the first global latitude-season distribution of the emission, established over three Martian years. The results are globally consistent with previously available measurements of dedicated limb nightglow obtained during the first Martian year of MEx (MY27). We compared the ensemble of both data sets with the predictions of the Laboratoire de Meteorologie Dynamique Mars General Circulation Model (LMD-MGCM), with the addition of the full chemistry of N atoms. We find an overall agreement between the observed and modeled airglow intensities, but discrepancies are also found. The frequency and magnitude of the NO airglow observations show important asymmetries between the Northern and the Southern Hemispheres. There is no detection of emission near the poles during equinox conditions, while the model predicts that it should be most intense because of a circulation with two descending branches at the poles.
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- 2013
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29. Observation of a Charge Density Wave Incommensuration Near the Superconducting Dome in CuxTiSe2
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Ken Finkelstein, Sangjun Lee, Jacob Ruff, Stephan Rosenkranz, Anshul Kogar, Stella X.-L. Sun, Goran Karapetrov, Yizhi Fang, G. A. de la Peña, Peter Abbamonte, and David B. Lioi
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Diffraction ,Physics ,Superconductivity ,Work (thermodynamics) ,Condensed matter physics ,Intercalation (chemistry) ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Copper ,Dome (geology) ,chemistry ,Condensed Matter::Superconductivity ,0103 physical sciences ,Condensed Matter::Strongly Correlated Electrons ,010306 general physics ,0210 nano-technology ,Charge density wave ,Phase diagram - Abstract
X-ray diffraction was employed to study the evolution of the charge density wave (CDW) in Cu_{x}TiSe_{2} as a function of copper intercalation in order to clarify the relationship between the CDW and superconductivity. The results show a CDW incommensuration arising at an intercalation value coincident with the onset of superconductivity at around x=0.055(5). Additionally, it was found that the charge density wave persists to higher intercalant concentrations than previously assumed, demonstrating that the CDW does not terminate inside the superconducting dome. A charge density wave peak was observed in samples up to x=0.091(6), the highest copper concentration examined in this study. The phase diagram established in this work suggests that charge density wave incommensuration may play a role in the formation of the superconducting state.
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- 2017
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30. How fast does the clock of Finance run? - A time-definition enforcing scale invariance and quantifying overnights
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Caraglio, Michele, Baldovin, Fulvio, and Stella, Attilio L.
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FOS: Economics and business ,Statistical Finance (q-fin.ST) ,Quantitative Finance - Computational Finance ,Statistical Mechanics (cond-mat.stat-mech) ,Physics - Data Analysis, Statistics and Probability ,FOS: Physical sciences ,Quantitative Finance - Statistical Finance ,Computational Finance (q-fin.CP) ,Data Analysis, Statistics and Probability (physics.data-an) ,Condensed Matter - Statistical Mechanics - Abstract
A symmetry-guided definition of time may enhance and simplify the analysis of historical series with recurrent patterns and seasonalities. By enforcing simple-scaling and stationarity of the distributions of returns, we identify a successful protocol of time definition in Finance. The essential structure of the stochastic process underlying the series can thus be analyzed within a most parsimonious symmetry scheme in which multiscaling is reduced in the quest of a time scale additive and independent of moment-order in the distribution of returns. At the same time, duration of periods in which markets remain inactive are properly quantified by the novel clock, and the corresponding (e.g., overnight) returns are consistently taken into account for financial applications., 9 pages, 8 figures
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- 2016
31. A simple framework for modelling the photochemical response to solar spectral irradiance variability in the stratosphere
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Simon Chabrillat, Stella M. L. Melo, Sébastien Viscardy, R. Muncaster, M. S. Bourqui, and Paul Charbonneau
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Solar minimum ,Atmospheric Science ,Coefficient of determination ,Linear model ,Irradiance ,Perturbation (astronomy) ,Atmospheric sciences ,Photochemistry ,Solar irradiance ,lcsh:QC1-999 ,lcsh:Chemistry ,lcsh:QD1-999 ,Climatology ,Ozone layer ,Environmental science ,Stratosphere ,lcsh:Physics - Abstract
The stratosphere is thought to play a central role in the atmospheric response to solar irradiance variability. Recent observations suggest that the spectral solar irradiance (SSI) variability involves significant time-dependent spectral variations, with variable degrees of correlation between wavelengths, and new reconstructions are being developed. In this paper, we propose a simplified modelling framework to characterise the effect of short term SSI variability on stratospheric ozone. We focus on the pure photochemical effect, for it is the best constrained one. The photochemical effect is characterised using an ensemble simulation approach with multiple linear regression analysis. A photochemical column model is used with interactive photolysis for this purpose. Regression models and their coefficients provide a characterisation of the stratospheric ozone response to SSI variability and will allow future inter-comparisons between different SSI reconstructions. As a first step in this study, and to allow comparison with past studies, we take the representation of SSI variability from the Lean (1997) solar minimum and maximum spectra. First, solar maximum-minimum response is analysed for all chemical families and partitioning ratios, and is compared with past studies. The ozone response peaks at 0.18 ppmv (approximately 3%) at 37 km altitude. Second, ensemble simulations are regressed following two linear models. In the simplest case, an adjusted coefficient of determination R2 larger than 0.97 is found throughout the stratosphere using two predictors, namely the previous day's ozone perturbation and the current day's solar irradiance perturbation. A better accuracy (R2 larger than 0.9992) is achieved with an additional predictor, the previous day's solar irradiance perturbation. The regression models also provide simple parameterisations of the ozone perturbation due to SSI variability. Their skills as proxy models are evaluated independently against the photochemistry column model. The bias and RMS error of the best regression model are found smaller than 1% and 15% of the ozone response, respectively. Sensitivities to initial conditions and to magnitude of the SSI variability are also discussed.
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- 2012
32. The Solar Spectral Irradiance as a Function of the Mg ii Index for Atmosphere and Climate Modelling
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Werner Schmutz, Gérard Thuillier, Alexander Shapiro, Matthew T. DeLand, Stella M. L. Melo, David Bolsée, STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Science Systems and Applications, Inc. [Lanham] (SSAI), Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), and Canadian Space Agency (CSA)
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010504 meteorology & atmospheric sciences ,[SDE.MCG]Environmental Sciences/Global Changes ,Irradiance ,Solar irradiance ,01 natural sciences ,7. Clean energy ,Standard deviation ,Spectral line ,Atmosphere ,0103 physical sciences ,Calibration ,010303 astronomy & astrophysics ,SOLSPEC ,0105 earth and related environmental sciences ,Remote sensing ,Physics ,Neutron monitor ,[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,Astronomy and Astrophysics ,ATLAS ,[PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,Wavelength ,Solar spectrum reconstruction ,[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology ,13. Climate action ,Space and Planetary Science ,Mg ii index - Abstract
We present a new method to reconstruct the solar spectrum irradiance in the Ly α – 400 nm region, and its variability, based on the Mg ii index and neutron-monitor measurements. Measurements of the solar spectral irradiance available in the literature have been made with different instruments at different times and different spectral ranges. However, climate studies require harmonised data sets. This new approach has the advantage of being independent of the absolute calibration and aging of the instruments. First, the Mg ii index is derived using solar spectra from Ly α (121 nm) to 410 nm measured from 1978 to 2010 by several space missions. The variability of the spectra with respect to a chosen reference spectrum as a function of time and wavelength is scaled to the derived Mg ii index. The set of coefficients expressing the spectral variability can be applied to the chosen reference spectrum to reconstruct the solar spectra within a given time frame or Mg ii index values. The accuracy of this method is estimated using two approaches: direct comparison with particular cases where solar spectra are available from independent measurements, and calculating the standard deviation between the measured spectra and their reconstruction. From direct comparisons with measurements we obtain an accuracy of about 1 to 2%, which degrades towards Ly α. In a further step, we extend our solar spectral-irradiance reconstruction back to the Maunder Minimum introducing the relationship between the Mg ii index and the neutron-monitor data. Consistent measurements of the Mg ii index are not available prior to 1978. However, we remark that over the last three solar cycles, the Mg ii index shows strong correlation with the modulation potential determined from the neutron-monitor data. Assuming that this correlation can be applied to the past, we reconstruct the Mg ii index from the modulation potential back to the Maunder Minimum, and obtain the corresponding solar spectral-irradiance reconstruction back to that period. As there is no direct measurement of the spectral irradiance for this period we discuss this methodology in light of the other proposed approaches available in the literature. The use of the cosmogenic-isotope data provides a major advantage: it provides information about solar activity over several thousands years. Using technology of today, we can calibrate the solar irradiance against activity and thus reconstruct it for the times when cosmogenic-isotope data are available. This calibration can be re-assessed at any time, if necessary.
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- 2012
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33. Middle atmosphere response to the solar cycle in irradiance and ionizing particle precipitation
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Stella M. L. Melo, Victor Fomichev, Ilya Usoskin, K. Semeniuk, John C. McConnell, and C. Fu
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Physics ,Solar minimum ,Atmospheric Science ,Sunspot ,Radiative forcing ,Atmospheric sciences ,Solar maximum ,Solar irradiance ,lcsh:QC1-999 ,Solar cycle ,lcsh:Chemistry ,Atmosphere ,lcsh:QD1-999 ,Climatology ,Physics::Space Physics ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Stratosphere ,lcsh:Physics ,Physics::Atmospheric and Oceanic Physics - Abstract
The impact of NOx and HOx production by three types of energetic particle precipitation (EPP), auroral zone medium and high energy electrons, solar proton events and galactic cosmic rays on the middle atmosphere is examined using a chemistry climate model. This process study uses ensemble simulations forced by transient EPP derived from observations with one-year repeating sea surface temperatures and fixed chemical boundary conditions for cases with and without solar cycle in irradiance. Our model results show a wintertime polar stratosphere ozone reduction of between 3 and 10 % in agreement with previous studies. EPP is found to modulate the radiative solar cycle effect in the middle atmosphere in a significant way, bringing temperature and ozone variations closer to observed patterns. The Southern Hemisphere polar vortex undergoes an intensification from solar minimum to solar maximum instead of a weakening. This changes the solar cycle variation of the Brewer-Dobson circulation, with a weakening during solar maxima compared to solar minima. In response, the tropical tropopause temperature manifests a statistically significant solar cycle variation resulting in about 4 % more water vapour transported into the lower tropical stratosphere during solar maxima compared to solar minima. This has implications for surface temperature variation due to the associated change in radiative forcing.
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- 2011
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34. Equity, social determinants and public health programmes - the case of oral health
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Stella Y. L. Kwan and Poul Erik Petersen
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medicine.medical_specialty ,Economic growth ,business.industry ,Public health ,Public Health, Environmental and Occupational Health ,Health services research ,International health ,Health equity ,Health promotion ,Health care ,medicine ,Social determinants of health ,business ,General Dentistry ,Health policy - Abstract
The WHO Commission on Social Determinants of Health issued the 2008 report 'Closing the gap within a generation - health equity through action on the social determinants of health' in response to the widening gaps, within and between countries, in income levels, opportunities, life expectancy, health status, and access to health care. Most individuals and societies, irrespective of their philosophical and ideological stance, have limits as to how much unfairness is acceptable. In 2010, WHO published another important report on 'Equity, Social Determinants and Public Health Programmes', with the aim of translating knowledge into concrete, workable actions. Poor oral health was flagged as a severe public health problem. Oral disease and illness remain global problems and widening inequities in oral health status exist among different social groupings between and within countries. The good news is that means are available for breaking poverty and reduce if not eliminate social inequalities in oral health. Whether public health actions are initiated simply depends on the political will. The Ottawa Charter for Health Promotion (1986) and subsequent charters have emphasized the importance of policy for health, healthy environments, healthy lifestyles, and the need for orientation of health services towards health promotion and disease prevention. This report advocates that oral health for all can be promoted effectively by applying this philosophy and some major public health actions are outlined.
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- 2011
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35. The Shape of the Solar Limb: Models and Observations
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Stella M. L. Melo, M. Haberreiter, C. I. Short, Djelloul Djafer, Sabatino Sofia, Gérard Thuillier, Jennyfer Claudel, Werner Schmutz, Alexander Shapiro, N. Mein, STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Tamanrasset (CRAAG), Centre de Recherche en Astronomie Astrophysique et Géophysique (CRAAG), Unité de Recherche Appliquée en Energies Renouvelables (URAER), Ministère de l'Enseignement Supérieur et de la Recherche Scientifique [Algérie] (MESRS), Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC), Observatoire de Paris - Site de Paris (OP), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Canadian Space Agency (CSA), Saint Mary's University [Halifax], Department of Astronomy [New Haven], and Yale University [New Haven]
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010504 meteorology & atmospheric sciences ,Opacity ,Continuum (design consultancy) ,01 natural sciences ,symbols.namesake ,Optics ,0103 physical sciences ,Radiative transfer ,Astrophysics::Solar and Stellar Astrophysics ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Physics ,Sunspot ,integumentary system ,[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,business.industry ,Empirical modelling ,Astronomy and Astrophysics ,[PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,Computational physics ,Fraunhofer lines ,Wavelength ,Space and Planetary Science ,Inflection point ,Physics::Space Physics ,symbols ,Astrophysics::Earth and Planetary Astrophysics ,business - Abstract
International audience; In this paper we compare observed, empirical, and modelled solar limb profiles and discuss their potential use to derive physical properties of the solar atmosphere. The PHOENIX, SolMod3D, and COSI radiative transfer codes as well as VAL-C models are used to calculate the solar limb shape under different assumptions. The main properties of each model are shown. The predicted limb shape as a function of wavelength for different features on the solar disk, such as quiet Sun, sunspots, and faculae, is investigated. These models provide overall consistent limb shapes with some discrepancies that are discussed here in terms of differences in solar atmosphere models, opacities, and the algorithms used to derive the solar limb profile. Our analysis confirms that the most common property of all models is limb shapes that are much steeper than what is observed, or predicted by the available empirical models. Furthermore, we have investigated the role of the Fraunhofer lines within the spectral domain used for the solar limb measurements. Our results show that the presence of the Fraunhofer lines significantly displaces the limb inflection point from its position estimated assuming only the photospheric continuum. The PICARD satellite, launched on 15 June 2010, will provide measurements of the limb shape at several wavelengths. This work shows that the precision of these measurements allows for discrimination among the available models.
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- 2010
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36. O desafio da coordenação e seus impactos sobre a competitividade de cadeias e sistemas agroindustriais Challenge of coordenation and its impacts on the competitiveness between chains and agribusiness systems
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Maria Stella B. L. de Melo Saab, Marcos Fava Neves, and Leandro Del Grande Cláudio
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coordenação ,cadeias ,carnes ,competitiveness ,coordination ,meats ,agribusiness systems ,chains ,sistemas agroindustriais ,lcsh:Animal culture ,competitividade ,lcsh:SF1-1100 - Abstract
Este artigo pretende apresentar alguns dos conceitos de coordenação de sistemas agroindustriais (SAGs) e de competitividade entre cadeias, mais especificamente as cadeias de carnes (bovinos, suínos e aves). Em seguida, são analisados alguns exemplos recentes de diferentes formas de coordenação de SAGs e como elas afetam a competitividade entre as cadeias.This paper intends to present some of the concepts of coordination of agribusiness systems (AGSs) and of competitiveness between chains, specifically meat chains (beef, pork and chicken meat). Then, some recent examples of different forms of coordination of AGSs are analysed and also how they affect competitiveness between the chains.
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- 2009
37. World Health Organization global oral health strategies for oral health promotion and disease prevention in the twenty-first century
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Poul Erik Petersen and Stella Y. L. Kwan
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medicine.medical_specialty ,business.industry ,Public health ,Incidence (epidemiology) ,Public Health, Environmental and Occupational Health ,Dentistry ,Developing country ,medicine.disease ,Obesity ,stomatognathic diseases ,Health promotion ,Acquired immunodeficiency syndrome (AIDS) ,Environmental health ,Tooth loss ,medicine ,medicine.symptom ,business ,Developed country - Abstract
Despite great improvements in oral health in the past decades, oral disease remains a major public health problem worldwide. The burden of oral disease is particularly high among the disadvantaged population groups in both developing and developed countries. The pattern of oral disease reflects distinct risk profiles across countries that are related to living conditions, lifestyles, environmental factors, and the availability and accessibility of oral health services. In several developing countries, people at large do not benefit from preventive oral health programmes. It is expected that the incidence of dental caries will increase in the near future in many of these countries as a result of growing consumption of sugars and inadequate exposure to fluorides. With the rising use of tobacco in developing countries, the risk of periodontal disease, tooth loss and oral cancer may therefore increase. Several oral diseases are linked to non-communicable chronic diseases or conditions that share common risk factors, such as diabetes, obesity and cancer. Similarly, general diseases often have oral manifestations (e.g. diabetes or HIV/AIDS).
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- 2009
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38. Validation of NO2 and NO from the Atmospheric Chemistry Experiment (ACE)
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Marco Ridolfi, James R. Drummond, Valéry Catoire, G. P. Stiller, Gloria L. Manney, Stella M. L. Melo, David W. T. Griffith, Florence Goutail, Matthias Schneider, Filip Vanhellemont, Craig S. Haley, Nicholas B. Jones, James E. Taylor, Piera Raspollini, T. E. Kerzenmacher, Andreas Richter, C. T. McElroy, Jean-Pierre Pommereau, Jason Zou, Donal P. Murtagh, Chris A. McLinden, Joseph M. Zawodny, Michael Höpfner, R. L. Batchelor, Caroline R. Nowlan, F. Nichitiu, I. Kramer, Nathalie Huret, C. D. Boone, Gwenaël Berthet, C. Tétard, J. Kar, John P. Burrows, Otto Schrems, Thorsten Warneke, Thomas Blumenstock, Bernd Funke, Leonard K. Amekudzi, F. Hendrick, Denis Dufour, M. A. Wolff, E. Dupuy, Cora E. Randall, Colette Brogniez, S. Mikuteit, M. Toohey, M. Silicani, Manuel López-Puertas, E. J. Llewellyn, Klaus Bramstedt, J. Dodion, Kim Strong, Didier Fussen, Peter F. Bernath, Justus Notholt, C. Piccolo, Samuel Brohede, and Kaley A. Walker
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Atmospheric Science ,010504 meteorology & atmospheric sciences ,Spectrometer ,Atmospheric sciences ,7. Clean energy ,01 natural sciences ,Occultation ,SCIAMACHY ,010309 optics ,Troposphere ,13. Climate action ,Atmospheric chemistry ,0103 physical sciences ,Nadir ,Sunrise ,Stratosphere ,0105 earth and related environmental sciences ,Remote sensing - Abstract
Vertical profiles of NO2 and NO have been obtained from solar occultation measurements by the Atmospheric Chemistry Experiment (ACE), using an infrared Fourier Transform Spectrometer (ACE-FTS) and (for NO2) an ultraviolet-visible-near-infrared spectrometer, MAESTRO (Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation). In this paper, the quality of the ACE-FTS version 2.2 NO2 and NO and the MAESTRO version 1.2 NO2 data are assessed using other solar occultation measurements (HALOE, SAGE II, SAGE III, POAM III, SCIAMACHY), stellar occultation measurements (GOMOS), limb measurements (MIPAS, OSIRIS), nadir measurements (SCIAMACHY), balloon-borne measurements (SPIRALE, SAOZ) and ground-based measurements (UV-VIS, FTIR). Time differences between the comparison measurements were reduced using either a tight coincidence criterion, or where possible, chemical box models. ACE-FTS NO2 and NO and the MAESTRO NO2 are generally consistent with the correlative data. The ACE-FTS and MAESTRO NO2 volume mixing ratio (VMR) profiles agree with the profiles from other satellite data sets to within about 20% between 25 and 40 km, with the exception of MIPAS ESA (for ACE-FTS) and SAGE II (for ACE-FTS (sunrise) and MAESTRO) and suggest a negative bias between 23 and 40 km of about 10%. MAESTRO reports larger VMR values than the ACE-FTS. In comparisons with HALOE, ACE-FTS NO VMRs typically (on average) agree to ±8% from 22 to 64 km and to +10% from 93 to 105 km, with maxima of 21% and 36%, respectively. Partial column comparisons for NO2 show that there is quite good agreement between the ACE instruments and the FTIRs, with a mean difference of +7.3% for ACE-FTS and +12.8% for MAESTRO.
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- 2008
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39. Summertime stratospheric processes at northern mid-latitudes: comparisons between MANTRA balloon measurements and the Canadian Middle Atmosphere Model
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B. J. Williams-Rioux, Kimberly Strong, C. T. McElroy, J. de Grandpré, J. R. Olson, David W. Tarasick, P. F. Fogal, Stella M. L. Melo, Jonathan Davies, Frank J. Murcray, Charles McLandress, Ronald D. Blatherwick, K. Semeniuk, Theodore G. Shepherd, and John C. McConnell
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Mantra ,Atmospheric Science ,Middle latitudes ,Climatology ,Environmental science ,Satellite ,Atmospheric model ,Atmospheric sciences ,Stratosphere ,Late summer - Abstract
In this paper we report on a study conducted using the Middle Atmospheric Nitrogen TRend Assessment (MANTRA) balloon measurements of stratospheric constituents and temperature and the Canadian Middle Atmosphere Model (CMAM). Three different kinds of data are used to assess the inter-consistency of the combined dataset: single profiles of long-lived species from MANTRA 1998, sparse climatologies from the ozonesonde measurements during the four MANTRA campaigns and from HALOE satellite measurements, and the CMAM climatology. In doing so, we evaluate the ability of the model to reproduce the measured fields and to thereby test our ability to describe mid-latitude summertime stratospheric processes. The MANTRA campaigns were conducted at Vanscoy, Saskatchewan, Canada (52° N, 107° W) in late August and early September of 1998, 2000, 2002 and 2004. During late summer at mid-latitudes, the stratosphere is close to photochemical control, providing an ideal scenario for the study reported here. From this analysis we find that: (1) reducing the value for the vertical diffusion coefficient in CMAM to a more physically reasonable value results in the model better reproducing the measured profiles of long-lived species; (2) the existence of compact correlations among the constituents, as expected from independent measurements in the literature and from models, confirms the self-consistency of the MANTRA measurements; and (3) the 1998 measurements show structures in the chemical species profiles that can be associated with transport, adding to the growing evidence that the summertime stratosphere can be much more disturbed than anticipated. The mechanisms responsible for such disturbances need to be understood in order to assess the representativeness of the measurements and to isolate long-term trends.
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- 2008
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40. Environmental Aspects of Domestic Cat Care and Management: Implications for Cat Welfare
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Stella, Judith L. and Croney, Candace C.
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Article Subject - Abstract
Domestic cats (Felis silvestris catus) are the most commonly kept companion animals in the US with large populations of owned (86 million), free-roaming (70 million), research (13,000), and shelter (2-3 million) cats. Vast numbers of cats are maintained in homes and other facilities each year and are reliant on humans for all of their care. Understanding cat behavior and providing the highest quality environments possible, including positive human-cat interactions, based on research could help improve the outcomes of biomedical research, shelter adoptions, and veterinary care, as well as overall cat welfare. Often, however, cats’ needs are inadequately met in homes and some aspects may also not be well met in research colonies and shelters, despite the fact that similar problems are likely to be encountered in all of these environments. This paper provides a brief overview of common welfare challenges associated with indoor housing of domestic cats. Essential considerations for cage confinement are reviewed, along with implications of poor cat coping, such as weakening of the human-animal bond and relinquishment to shelters. The important role that environmental management plays in cat behavior and welfare outcomes is explored along with the need for additional research in key areas.
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- 2016
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41. Observation of a Charge Density Wave Incommensuration Near the Superconducting Dome in CuxTiSe2
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Kogar, Anshul, de la Pena, Gilberto A., Lee, Sangjun, Fang, Yizhi, Sun, Stella X. -L., Lioi, David B., Karapetrov, Goran, Finkelstein, Kenneth D., Ruff, Jacob P. C., Abbamonte, Peter, and Rosenkranz, Stephan
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Superconductivity (cond-mat.supr-con) ,Condensed Matter - Strongly Correlated Electrons ,Strongly Correlated Electrons (cond-mat.str-el) ,Condensed Matter - Superconductivity ,Condensed Matter::Superconductivity ,FOS: Physical sciences ,Condensed Matter::Strongly Correlated Electrons - Abstract
X-ray diffraction was employed to study the evolution of the charge density wave (CDW) in CuxTiSe2 as a function of copper intercalation in order to clarify the relationship between the CDW and superconductivity. The results show a CDW incommensuration arising at an intercalation value coincident with the onset of superconductivity at around x=0.055(5). Additionally, it was found that the charge density wave persists to higher intercalant concentrations than previously assumed, demonstrating that the CDW does not terminate inside the superconducting dome. A charge density wave peak was observed in samples up to x=0.091(6), the highest copper concentration examined in this study. The phase diagram established in this work suggests that charge density wave incommensuration may play a role in the formation of the superconducting state., Comment: 5 pages, 4 figures
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- 2016
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42. Structure and conformational analysis of CFC-113 by density functional theory calculations and FTIR spectroscopy
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Karine Le Bris, Jason C. Ng, Kimberly Strong, and Stella M. L. Melo
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Materials science ,Enthalpy ,Molecular physics ,Atomic and Molecular Physics, and Optics ,Vibration ,Nuclear magnetic resonance ,Molecular geometry ,Normal mode ,Rectangular potential barrier ,Density functional theory ,Physical and Theoretical Chemistry ,Fourier transform infrared spectroscopy ,Conformational isomerism ,Spectroscopy - Abstract
Altitude-resolved volume mixing ratio profiles of CFC-113 have recently become available on a global scale with the Atmospheric Chemistry Experiment (ACE) satellite mission. However, the accuracy of the retrieval is currently limited by the uncertainties on the spectroscopic parameters of CFC-113. This paper reports on the geometrical structure, harmonic frequencies and intensities in the mid-infrared region of the two conformers of CFC-113 and the evaluation of whether theoretical calculations reproduce measurements. The calculations are performed using density functional theory at the B3LYP/6-311+G(3df) level. The molecular geometry parameters, the enthalpy difference and the potential barrier between conformers are calculated. The harmonic frequency of the normal modes of vibration are presented and accurately compared to experimental data. Overtones and combination bands are assigned in the 1200– 2500 cm � 1 region.
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- 2007
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43. Lightning-produced NO2 observed by two ground-based UV-visible spectrometers at Vanscoy, Saskatchewan in August 2004
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Florence Goutail, Chris A. McLinden, Kim Strong, A. Fraser, and Stella M. L. Melo
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Lightning detection ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,Thunder ,Meteorology ,media_common.quotation_subject ,Doppler radar ,Storm ,Atmospheric sciences ,01 natural sciences ,Lightning ,law.invention ,010309 optics ,Flash (photography) ,13. Climate action ,law ,Sky ,0103 physical sciences ,Thunderstorm ,Environmental science ,0105 earth and related environmental sciences ,media_common - Abstract
Ground-based measurements of ozone and NO2 differential slant columns by the SAOZ (Système d'Analyse par Observations Zénithales) and UT-GBS (University of Toronto Ground-Based Spectrometer) instruments during the MANTRA 2004 field campaign are presented herein. During the afternoon of 28 August, a thunderstorm passed over the instruments, which were installed at Vanscoy, Saskatchewan (52° N, 107° W). Enhanced differential slant columns of ozone and NO2 were observed by both instruments during the storm, with maximum values of two and 25 times the expected clear sky columns, respectively. The enhanced ozone differential slant columns are primarily due to the longer path traversed by the solar radiation caused by multiple scattering inside the thick cloud layer associated with the thunderstorm. The enhanced NO2 columns are partly attributed to NOx production by lightning. Two new methods are used to separate the NO2 enhancements into contributions from the longer path length and production by lightning. Combining the observed excess NO2 with lightning flash data from the Canadian Lightning Detection Network and Environment Canada Doppler radar measurements, the production of NO2 molecules per lightning flash is determined. Using these two methods, the best estimate of the production rate is found to be (7.88±2.52)×1026 molecules NO2/flash from the UT-GBS and (6.81±2.17)×1026 molecules NO2/flash from SAOZ. These results are consistent with the range of previous estimates reported in the literature.
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- 2007
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44. State of the Climate in 2014
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Aaron-Morrison, Arlene P., Ackerman, Steven A., Adams, Nicolaus G., Adler, Robert F., Albanil, Adelina, Alfaro, E. J., Allan, Rob, Alves, Lincoln M., Amador, Jorge A., Andreassen, L. M., Arendt, A., Arévalo, Juan, Arndt, Derek S., Arzhanova, N. M., Aschan, M. M., Azorin-Molina, César, Banzon, Viva, Bardin, M. U., Barichivich, Jonathan, Baringer, Molly O., Barreira, Sandra, Baxter, Stephen, Bazo, Juan, Becker, Andreas, Bedka, Kristopher M., Behrenfeld, Michael J., Bell, Gerald D., Belmont, M., Benedetti, Angela, Bernhard, G., Berrisford, Paul, Berry, David I., Bettolli, María L., Bhatt, U. S., Bidegain, Mario, Bill, Brian D., Billheimer, Sam, Bissolli, Peter, Blake, Eric S., Blunden, Jessica, Bosilovich, Michael G., Boucher, Olivier, Boudet, Dagne, Box, J. E., Boyer, Tim, Braathen, Geir O., Bromwich, David H., Brown, R., Bulygina, Olga N., Burgess, D., Calderón, Blanca, Camargo, Suzana J., Campbell, Jayaka D., Cappelen, J., Carrasco, Gualberto, Carter, Brendan R., Chambers, Don P., Chandler, Elise, Christiansen, Hanne H., Christy, John R., Chung, Daniel, Chung, E. S., Cinque, Kathy, Clem, Kyle R., Coelho, Caio A., Cogley, J. G., Coldewey-Egbers, Melanie, Colwell, Steve, Cooper, Owen R., Copland, L., Cosca, Catherine E., Cross, Jessica N., Crotwell, Molly J., Crouch, Jake, Davis, Sean M., De Eyto, Elvira, De Jeu, Richard A.M., De Laat, Jos, Degasperi, Curtis L., Degenstein, Doug, Demircan, M., Derksen, C., Destin, Dale, Di Girolamo, Larry, Di Giuseppe, F., Diamond, Howard J., Dlugokencky, Ed J., Dohan, Kathleen, Dokulil, Martin T., Dolgov, A. V., Dolman, A. Johannes, Domingues, Catia M., Donat, Markus G., Dong, Shenfu, Dorigo, Wouter A., Dortch, Quay, Doucette, Greg, Drozdov, D. S., Ducklow, Hugh, Dunn, Robert J.H., Durán-Quesada, Ana M., Dutton, Geoff S., Ebrahim, A., Elkharrim, M., Elkins, James W., Espinoza, Jhan C., Etienne-Leblanc, Sheryl, Evans, Thomas E., Famiglietti, James S., Farrell, S., Fateh, S., Fausto, Robert S., Fedaeff, Nava, Feely, Richard A., Feng, Z., Fenimore, Chris, Fettweis, X., Fioletov, Vitali E., Flemming, Johannes, Fogarty, Chris T., Fogt, Ryan L., Folland, Chris, Fonseca, C., Fossheim, M., Foster, Michael J., Fountain, Andrew, Francis, S. D., Franz, Bryan A., Frey, Richard A., Frith, Stacey M., Froidevaux, Lucien, Ganter, Catherine, Garzoli, Silvia, Gerland, S., Gobron, Nadine, Goldenberg, Stanley B., Gomez, R. Sorbonne, Goni, Gustavo, Goto, A., Grooß, J. U., Gruber, Alexander, Guard, Charles Chip, Gugliemin, Mauro, Gupta, S. K., Gutiérrez, J. M., Hagos, S., Hahn, Sebastian, Haimberger, Leo, Hakkarainen, J., Hall, Brad D., Halpert, Michael S., Hamlington, Benjamin D., Hanna, E., Hansen, K., Hanssen-Bauer, I., Harris, Ian, Heidinger, Andrew K., Heikkilä, A., Heil, A., Heim, Richard R., Hendricks, S., Hernández, Marieta, Hidalgo, Hugo G., Hilburn, Kyle, Ho, Shu Peng Ben, Holmes, R. M., Hu, Zeng Zhen, Huang, Boyin, Huelsing, Hannah K., Huffman, George J., Hughes, C., Hurst, Dale F., Ialongo, I., Ijampy, J. A., Ingvaldsen, R. B., Inness, Antje, Isaksen, K., Ishii, Masayoshi, Jevrejeva, Svetlana, Jiménez, C., Jin, Xiangze, Johannesen, E., John, Viju, Johnsen, B., Johnson, Bryan, Johnson, Gregory C., Jones, Philip D., Joseph, Annie C., Jumaux, Guillaume, Kabidi, Khadija, Kaiser, Johannes W., Kato, Seiji, Kazemi, A., Keller, Linda M., Kendon, Mike, Kennedy, John, Kerr, Kenneth, Kholodov, A. L., Khoshkam, Mahbobeh, Killick, Rachel, Kim, Hyungjun, Kim, S. J., Kimberlain, Todd B., Klotzbach, Philip J., Knaff, John A., Kobayashi, Shinya, Kohler, J., Korhonen, Johanna, Korshunova, Natalia N., Kovacs, K. M., Kramarova, Natalya, Kratz, D. P., Kruger, Andries, Kruk, Michael C., Kudela, Raphael, Kumar, Arun, Lakatos, M., Lakkala, K., Lander, Mark A., Landsea, Chris W., Lankhorst, Matthias, Lantz, Kathleen, Lazzara, Matthew A., Lemons, P., Leuliette, Eric, L’Heureux, Michelle, Lieser, Jan L., Lin, I. I., Liu, Hongxing, Liu, Yinghui, Locarnini, Ricardo, Loeb, Norman G., Lo Monaco, Claire, Long, Craig S., López Álvarez, Luis Alfonso, Lorrey, Andrew M., Loyola, Diego, Lumpkin, Rick, Luo, Jing Jia, Luojus, K., Lydersen, C., Lyman, John M., Maberly, Stephen C., Maddux, Brent C., Malheiros Ramos, Andrea, Malkova, G. V., Manney, G., Marcellin, Vernie, Marchenko, S. S., Marengo, José A., Marra, John J., Marszelewski, Wlodzimierz, Martens, B., Martínez-Güingla, Rodney, Massom, Robert A., Mata, Mauricio M., Mathis, Jeremy T., May, Linda, Mayer, Michael, Mazloff, Matthew, McBride, Charlotte, McCabe, M. F., McCarthy, M., McClelland, J. W., McGree, Simon, McVicar, Tim R., Mears, Carl A., Meier, W., Meinen, Christopher S., Mekonnen, A., Menéndez, Melisa, Mengistu Tsidu, G., Menzel, W. Paul, Merchant, Christopher J., Meredith, Michael P., Merrifield, Mark A., Metzl, N., Minnis, Patrick, Miralles, Diego G., Mistelbauer, T., Mitchum, Gary T., Monselesan, Didier, Monteiro, Pedro, Montzka, Stephen A., Morice, Colin, Mote, T., Mudryk, L., Mühle, Jens, Mullan, A. Brett, Nash, Eric R., Naveira-Garabato, Alberto C., Nerem, R. Steven, Newman, Paul A., Nieto, Juan José, Noetzli, Jeannette, O’Neel, S., Osborn, Tim J., Overland, J., Oyunjargal, Lamjav, Parinussa, Robert M., Park, E. Hyung, Parker, David, Parrington, M., Parsons, A. Rost, Pasch, Richard J., Pascual-Ramírez, Reynaldo, Paterson, Andrew M., Paulik, Christoph, Pearce, Petra R., Pelto, Mauri S., Peng, Liang, Perkins-Kirkpatrick, Sarah E., Perovich, D., Petropavlovskikh, Irina, Pezza, Alexandre B., Phillips, David, Pinty, Bernard, Pitts, Michael C., Pons, M. R., Porter, Avalon O., Primicerio, R., Proshutinsky, A., Quegan, Sean, Quintana, Juan, Rahimzadeh, Fatemeh, Rajeevan, Madhavan, Randriamarolaza, L., Razuvaev, Vyacheslav N., Reagan, James, Reid, Phillip, Reimer, Christoph, Rémy, Samuel, Renwick, James A., Revadekar, Jayashree V., Richter-Menge, J., Riffler, Michael, Rimmer, Alon, Rintoul, Steve, Robinson, David A., Rodell, Matthew, Rodríguez Solís, José L., Romanovsky, Vladimir E., Ronchail, Josyane, Rosenlof, Karen H., Roth, Chris, Rusak, James A., Sabine, Christopher L., Sallée, Jean Bapiste, Sánchez-Lugo, Ahira, Santee, Michelle L., Sawaengphokhai, P., Sayouri, Amal, Scambos, Ted A., Schemm, Jae, Schladow, S. Geoffrey, Schmid, Claudia, Schmid, Martin, Schmidtko, Sunke, Schreck, Carl J., Selkirk, H. B., Send, Uwe, Sensoy, Serhat, Setzer, Alberto, Sharp, M., Shaw, Adrian, Shi, Lei, Shiklomanov, A. I., Shiklomanov, Nikolai I., Siegel, David A., Signorini, Sergio R., Sima, Fatou, Simmons, Adrian J., Smeets, C. J.P.P., Smith, Sharon L., Spence, Jaqueline M., Srivastava, A. K., Stackhouse, Paul W., Stammerjohn, Sharon, Steinbrecht, Wolfgang, Stella, José L., Stengel, Martin, Stennett-Brown, Roxann, Stephenson, Tannecia S., Strahan, Susan, Streletskiy, D. A., Sun-Mack, Sunny, Swart, Sebastiaan, Sweet, William, Talley, Lynne D., Tamar, Gerard, Tank, S. E., Taylor, Michael A., Tedesco, M., Teubner, Katrin, Thoman, R. L., Thompson, Philip, Thomson, L., Timmermans, M. L., Tirnanes, Joaquin A., Tobin, Skie, Trachte, Katja, Trainer, Vera L., Tretiakov, M., Trewin, Blair C., Trotman, Adrian R., Tschudi, M., Van As, D., Van De Wal, R. S.W., van der A., Ronald J., Van Der Schalie, Robin, Van Der Schrier, Gerard, Van Der Werf, Guido R., Van Meerbeeck, Cedric J., Velicogna, I., Verburg, Piet, Vigneswaran, Bala, Vincent, Lucie A., Volkov, Denis, Vose, Russell S., Wagner, Wolfgang, Wåhlin, Anna, Wahr, J., Walsh, J., Wang, Chunzai, Wang, Junhong, Wang, Lei, Wang, M., Wang, Sheng Hung, Wanninkhof, Rik, Watanabe, Shohei, Weber, Mark, Weller, Robert A., Weyhenmeyer, Gesa A., Whitewood, Robert, Wijffels, Susan E., Wilber, Anne C., Wild, Jeanette D., Willett, Kate M., Williams, Michael J.M., Willie, Shem, Wolken, G., Wong, Takmeng, Wood, E. F., Woolway, R. Iestyn, Wouters, B., Xue, Yan, Yamada, Ryuji, Yim, So Young, Yin, Xungang, Young, Steven H., Yu, Lisan, Zahid, H., Zambrano, Eduardo, Zhang, Peiqun, Zhao, Guanguo, Zhou, Lin, Ziemke, Jerry R., Love-Brotak, S. Elizabeth, Gilbert, Kristin, Maycock, Tom, Osborne, Susan, Sprain, Mara, Veasey, Sara W., Ambrose, Barbara J., Griffin, Jessicca, Misch, Deborah J., Riddle, Deborah B., Young, Teresa, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), ICOS-ATC (ICOS-ATC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Earth and Climate
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0106 biological sciences ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,010604 marine biology & hydrobiology ,Perspective (graphical) ,15. Life on land ,01 natural sciences ,El Niño Southern Oscillation ,13. Climate action ,Climatology ,SDG 13 - Climate Action ,Environmental science ,SDG 14 - Life Below Water ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences - Abstract
Most of the dozens of essential climate variables monitored each year in this report continued to follow their long-term trends in 2014, with several setting new records. Carbon dioxide, methane, and nitrous oxide-the major greenhouse gases released into Earth's atmosphere-once again all reached record high average atmospheric concentrations for the year. Carbon dioxide increased by 1.9 ppm to reach a globally averaged value of 397.2 ppm for 2014. Altogether, 5 major and 15 minor greenhouse gases contributed 2.94 W m-2 of direct radiative forcing, which is 36% greater than their contributions just a quarter century ago. Accompanying the record-high greenhouse gas concentrations was nominally the highest annual global surface temperature in at least 135 years of modern record keeping, according to four independent observational analyses. The warmth was distributed widely around the globe's land areas, Europe observed its warmest year on record by a large margin, with close to two dozen countries breaking their previous national temperature records; many countries in Asia had annual temperatures among their 10 warmest on record; Africa reported above-average temperatures across most of the continent throughout 2014; Australia saw its third warmest year on record, following record heat there in 2013; Mexico had its warmest year on record; and Argentina and Uruguay each had their second warmest year on record. Eastern North America was the only major region to observe a below-average annual temperature. But it was the oceans that drove the record global surface temperature in 2014. Although 2014 was largely ENSO-neutral, the globally averaged sea surface temperature (SST) was the highest on record. The warmth was particularly notable in the North Pacific Ocean where SST anomalies signaled a transition from a negative to positive phase of the Pacific decadal oscillation. In the winter of 2013/14, unusually warm water in the northeast Pacific was associated with elevated ocean heat content anomalies and elevated sea level in the region. Globally, upper ocean heat content was record high for the year, reflecting the continued increase of thermal energy in the oceans, which absorb over 90% of Earth's excess heat from greenhouse gas forcing. Owing to both ocean warming and land ice melt contributions, global mean sea level in 2014 was also record high and 67 mm greater than the 1993 annual mean, when satellite altimetry measurements began. Sea surface salinity trends over the past decade indicate that salty regions grew saltier while fresh regions became fresher, suggestive of an increased hydrological cycle over the ocean expected with global warming. As in previous years, these patterns are reflected in 2014 subsurface salinity anomalies as well. With a now decade-long trans-basin instrument array along 26°N, the Atlantic meridional overturning circulation shows a decrease in transport of-4.2 ± 2.5 Sv decade-1. Precipitation was quite variable across the globe. On balance, precipitation over the world's oceans was above average, while below average across land surfaces. Drought continued in southeastern Brazil and the western United States. Heavy rain during April-June led to devastating floods in Canada's Eastern Prairies. Above-normal summer monsoon rainfall was observed over the southern coast of West Africa, while drier conditions prevailed over the eastern Sahel. Generally, summer monsoon rainfall over eastern Africa was above normal, except in parts of western South Sudan and Ethiopia. The south Asian summer monsoon in India was below normal, with June record dry. Across the major tropical cyclone basins, 91 named storms were observed during 2014, above the 1981-2010 global average of 82. The Eastern/Central Pacific and South Indian Ocean basins experienced significantly above-normal activity in 2014; all other basins were either at or below normal. The 22 named storms in the Eastern/Central Pacific was the basin's most since 1992. Similar to 2013, the North Atlantic season was quieter than most years of the last two decades with respect to the number of storms, despite the absence of El Niño conditions during both years. In higher latitudes and at higher elevations, increased warming continued to be visible in the decline of glacier mass balance, increasing permafrost temperatures, and a deeper thawing layer in seasonally frozen soil. In the Arctic, the 2014 temperature over land areas was the fourth highest in the 115-year period of record and snow melt occurred 20-30 days earlier than the 1998-2010 average. The Greenland Ice Sheet experienced extensive melting in summer 2014. The extent of melting was above the 1981-2010 average for 90% of the melt season, contributing to the second lowest average summer albedo over Greenland since observations began in 2000 and a record-low albedo across the ice sheet for August. On the North Slope of Alaska, new record high temperatures at 20-m depth were measured at four of five permafrost observatories. In September, Arctic minimum sea ice extent was the sixth lowest since satellite records began in 1979. The eight lowest sea ice extents during this period have occurred in the last eight years. Conversely, in the Antarctic, sea ice extent countered its declining trend and set several new records in 2014, including record high monthly mean sea ice extent each month from April to November. On 20 September, a record large daily Antarctic sea ice extent of 20.14 × 106 km2 occurred. The 2014 Antarctic stratospheric ozone hole was 20.9 million km2 when averaged from 7 September to 13 October, the sixth smallest on record and continuing a decrease, albeit statistically insignificant, in area since 1998.
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- 2015
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45. The hierarchical cluster analysis of oral health attitudes and behaviour using the Hiroshima University - Dental Behavioural Inventory (HU-DBI) among final year dental students in 17 countries
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Argy Polychronopoulou, Martin Kinirons, Stefano Petti, Maria do Carmo Matias Freire Goiâs, Stella Y. L. Kwan, Kang-Ju Kim, Eino Honkala, De-Yu Hu, Patcharawan Srisilapanan, Matthias Kalwitzki, Kevin Hak‐Kong Yip, Gérard Lévy, Takashi Komabayashi, F. A. C. Wright, Dominique Declerck, Makoto Kawamura, Linda S. Centore, and Ilana Eli
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Cross-Cultural Comparison ,Asia ,Health Behavior ,Students, Dental ,Dentistry ,Oral Health ,Oral health ,Dental education ,Northern ireland ,Oral hygiene ,Overall response rate ,Surveys and Questionnaires ,Cluster Analysis ,Humans ,Medicine ,Dental Care ,China ,General Dentistry ,business.industry ,Oral Hygiene ,Cross-cultural studies ,Europe ,South american ,business ,Attitude to Health ,Brazil ,Demography - Abstract
Objective: To explore and describe international oral health attitudes/behaviours among final year dental students. Methods: Validated translated versions of the Hiroshima University—Dental Behavioural Inventory (HU—DBI) questionnaire were administered to 1,096 final-year dental students in 17 countries. Hierarchical cluster analysis was conducted within the data to detect patterns and groupings. Results: The overall response rate was 72%. The cluster analysis identified two main groups among the countries. Group 1 consisted of twelve countries: one Oceanic (Australia), one Middle-Eastern (Israel), seven European (Northern Ireland, England, Finland, Greece, Germany, Italy, and France) and three Asian (Korea, Thailand and Malaysia) countries. Group 2 consisted of five countries: one South American (Brazil), one European (Belgium) and three Asian (China, Indonesia and Japan) countries. The percentages of ‘agree’ responses in three HU—DBI questionnaire items were significantly higher in Group 2 than in Group 1. They include: “I worry about the colour of my teeth.”; “I have noticed some white sticky deposits on my teeth.”; and “I am bothered by the colour of my gums.” Conclusion: Grouping the countries into international clusters yielded useful information for dentistry and dental education.
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- 2006
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46. Using airglow measurements to observe gravity waves in the Martian atmosphere
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J. C. McConnell, Kimberly Strong, Michael J. Taylor, A. Garcia-Munoz, O. Chiu, David L. Huestis, Tom G. Slanger, Ian C. McDade, Stella M. L. Melo, and Robert P. Lowe
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Atmospheric Science ,Gravitational wave ,Astrophysics::Instrumentation and Methods for Astrophysics ,Airglow ,Aerospace Engineering ,Astronomy and Astrophysics ,Atmosphere of Mars ,Astrobiology ,law.invention ,Orbiter ,Geophysics ,Space and Planetary Science ,law ,Computer Science::Computer Vision and Pattern Recognition ,Physics::Space Physics ,General Earth and Planetary Sciences ,Astrophysics::Earth and Planetary Astrophysics ,Gravity wave ,Geology ,Planetary exploration - Abstract
In this paper, we present the first results of model simulations of the airglow response to gravity waves propagating in the Martian atmosphere. This modeling activity has been done in support of the development of two systems to monitor gravity wave activity in the Martian atmosphere through the measurement of contrast in the images of selected airglow features: a zenith-sky imaging system (MARES-Ground) designed to operate from the ground, and an orbiter-based imaging system (MARES-GWIM). Both systems are also briefly described here as well.
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- 2006
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47. Retrieval of stratospheric NO2vertical profiles from ground‐based zenith‐sky DOAS measurements: Results for the MANTRA 1998 field campaign
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Eugene Rozanov, Matt Bassford, Stella M. L. Melo, Kimberly Strong, T. Egorova, C. T. McElroy, and K. E. Preston
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Atmosphere ,Atmospheric Science ,Meteorology ,Ozone layer ,Environmental science ,Sunrise ,Environmental pollution ,Sunset ,Oceanography ,Stratosphere ,Wind speed ,Zenith - Abstract
The importance of measurements of the vertical distribution of odd nitrogen in studies of ozone chemistry and climate change has long being recognized. In this paper, we use the optimal estimation method developed by Rodgers (1976, 1990) to retrieve NO2 vertical profiles from slant column observations made with a portable ultraviolet (UV)‐visible zenith‐sky spectrometer operated on the ground during the Middle Atmosphere Nitrogen TRend Assessment (MANTRA) balloon campaign carried out at Vanscoy, Saskatchewan, Canada (52°N, 107°W), from 18 to 25 August 1998. Late summer was chosen for the campaign because the stratospheric zonal wind velocity changes sign at that time. Under such conditions the stratospheric winds are at a minimum, leaving the stratosphere in a dynamically quiescent state and closer to photochemical control (Fahey et al., 2001; Fioletov and Shepherd, 2003). The NO2 profile retrieved from the ground‐based observations is compared with the co‐located and simultaneous NO2 profile mea...
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- 2005
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48. MANTRA ‐ A Balloon Mission to Study the Odd‐Nitrogen Budget of the Stratosphere
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Y. J. Rochon, A. Jofre, Jacek W. Kaminski, Stella M. L. Melo, Frank J. Murcray, J. R. Olson, C. Laurin, Caroline R. Nowlan, Robert O. Hall, James R. Drummond, E. Forsberg, Ronald D. Blatherwick, J. J. Kosters, Debra Wunch, P. F. Fogal, Volodya Savastiouk, Brendan M. Quine, S. Werchohlad, Clive Midwinter, H. Wu, Chris A. McLinden, Kimberly Strong, C. T. McElroy, M.R. Bassford, Brian Solheim, S. Brown, D. Sommerfeldt, K. Menzies, Jonathan Davies, D. J. Chartrand, D. V. Barton, George V. Bailak, A. Ullberg, and J. C. McConnell
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Atmospheric sounding ,Atmospheric Science ,Altitude ,Meteorology ,Atmospheric chemistry ,Ozone layer ,Northern Hemisphere ,Environmental science ,Environmental pollution ,Oceanography ,Balloon ,Stratosphere - Abstract
The Middle Atmosphere Nitrogen TRend Assessment (MANTRA) series of high‐altitude balloon flights is being undertaken to investigate changes in the concentrations of northern hemisphere mid‐latitude stratospheric ozone, and of nitrogen and chlorine compounds that play a role in ozone chemistry. Four campaigns have been carried out to date, all from Vanscoy, Saskatchewan, Canada (52°01'N, 107°02'W, 511.0 m). The first MANTRA mission took place in August 1998, with the balloon flight on 24 August 1998 being the first Canadian launch of a large high‐altitude balloon in about fifteen years. The balloon carried a payload of instruments to measure atmospheric composition, and made measurements from a float altitude of 32–38 km for one day. Three of these instruments had been flown on the Stratoprobe flights of the Atmospheric Environment Service (now the Meteorological Service of Canada) in the 1970s and early 1980s, providing a link to historical data predating the onset of mid‐latitude ozone loss. The...
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- 2005
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49. Gas phase UV and IR absorption spectra of CF3CH2CH2OH and F(CF2CF2)xCH2CH2OH (x=2, 3, 4)
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Naomi L. Stock, R. Dumoulin, Scott A. Mabury, J.A. Misner, L. Castera, Timothy J. Wallington, Michael D. Hurley, R.L. Waterland, Kimberly Strong, and Stella M. L. Melo
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Ir absorption ,Chemistry ,Organic Chemistry ,Photodissociation ,Analytical chemistry ,Infrared spectroscopy ,Biochemistry ,Diluent ,Spectral line ,Gas phase ,Inorganic Chemistry ,Environmental Chemistry ,Physical and Theoretical Chemistry ,Experimental methods ,Spectral resolution - Abstract
The UV and IR spectra of CF 3 CH 2 CH 2 OH and F(CF 2 CF 2 ) x CH 2 CH 2 OH ( x = 2, 3, 4) were investigated using computational and experimental techniques. Computational methods were used to show that CF 3 CH 2 CH 2 OH and F(CF 2 CF 2 ) x CH 2 CH 2 OH ( x = 2, 3) have UV absorption in the region 140–175 nm. Photolysis is therefore not a significant environmental loss mechanism for fluorinated alcohols. Experimental methods were used to record IR spectra for CF 3 CH 2 CH 2 OH and F(CF 2 CF 2 ) x CH 2 CH 2 OH ( x = 2, 3, 4) at spectral resolutions of 0.004–0.5 cm −1 with, and without, 700 Torr of air diluent. There was no discernable effect of total pressure or spectral resolution over the range studied. Calculated IR spectra agreed well with those measured experimentally, and were used to assign the IR spectra.
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- 2005
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50. Airglow on Mars: Some model expectations for the OH Meinel bands and the O IR atmospheric band
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A. García Muñoz, Ian C. McDade, J. C. McConnell, and Stella M. L. Melo
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Atmosphere ,Materials science ,Space and Planetary Science ,Excited state ,Photodissociation ,Vibrational energy relaxation ,Radiative transfer ,Airglow ,Astronomy and Astrophysics ,Mars Exploration Program ,Atomic physics ,Atmospheric sciences ,Sudden death - Abstract
This work presents model calculations of the diurnal airglow emissions from the OH Meinel bands and the O2 IR atmospheric band in the neutral atmosphere of Mars. A time-dependent photochemical model of the lower atmosphere below 80 km has been developed for this purpose. Special emphasis is placed on the nightglow emissions because of their potential to characterize the atomic oxygen profile in the 50–80 km region. Unlike on Earth, the OH Meinel emission rates are very sensitive to the details of the vibrational relaxation pathway. In the sudden death and collisional cascade limits, the maximum OH Meinel column intensities for emissions originating from a fixed upper vibrational level are calculated to be about 300 R, for transitions v ′ = 9 → v ′ ⩽ 8 , and 15,000 R, for transitions v ′ = 1 → v ′ = 0 , respectively. During the daytime the 1.27 μm emission from O2( a Δ g 1 ), primarily formed from ozone photodissociation, is of the order of MegaRayleighs (MR). Due to the long radiative lifetime of O2( a Δ g 1 ), a luminescent remnant of the dayglow extends to the dark side for about two hours. At night, excited molecular oxygen is expected to be produced through the three body reaction O + O + CO2. The column emission of this nighttime component of the airglow is estimated to amount to 25 kR. Both nightglow emissions, from the OH Meinel bands and the O2 IR atmospheric band, overlap in the 50–80 km region. Photodissociation of CO2 in the upper atmosphere and the subsequent transport of the atomic oxygen produced to the emitting layer are revealed as key factors in the nightglow emissions from these systems. The Mars 5 upper constraint for the product [H][O3] is revised on the basis of more recent values for the emission probabilities and collisional deactivation coefficients.
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- 2005
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