2,249 results on '"Sieverding, A."'
Search Results
2. Production of 44Ti and iron-group nuclei in the ejecta of 3D neutrino-driven supernovae
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Sieverding, Andre, Kresse, Daniel, and Janka, Hans-Thomas
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Astrophysics - High Energy Astrophysical Phenomena - Abstract
The radioactive isotopes of 44Ti and 56Ni are important products of explosive nucleosynthesis, which play a key role for supernova (SN) diagnostics and were detected in several nearby young SN remnants. However, most SN models based on non-rotating single stars predict yields of 44Ti that are much lower than the values inferred from observations. We present, for the first time, the nucleosynthesis yields from a self-consistent three-dimensional (3D) SN simulation of an approximately 19 Msun progenitor star that reaches an explosion energy comparable to that of SN 1987A and that covers the evolution of the neutrino-driven explosion until more than 7 seconds after core bounce. We find a significant enhancement of the Ti/Fe yield compared to recent spherically symmetric (1D) models and demonstrate that the long-time evolution is crucial to understand the efficient production of 44Ti due to the non-monotonic temperature and density histories of ejected mass elements. Additionally, we identify characteristic signatures of the nucleosynthesis in proton-rich ejecta, in particular high yields of 45Sc and 64Zn., Comment: 12 pages, 7 Figures, accepted for publication in ApJL
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- 2023
3. A Modular Ontology for MODS -- Metadata Object Description Schema
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Rayan, Rushrukh, Shimizu, Cogan, Sieverding, Heidi, and Hitzler, Pascal
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Computer Science - Computation and Language ,Computer Science - Artificial Intelligence - Abstract
The Metadata Object Description Schema (MODS) was developed to describe bibliographic concepts and metadata and is maintained by the Library of Congress. Its authoritative version is given as an XML schema based on an XML mindset which means that it has significant limitations for use in a knowledge graphs context. We have therefore developed the Modular MODS Ontology (MMODS-O) which incorporates all elements and attributes of the MODS XML schema. In designing the ontology, we adopt the recent Modular Ontology Design Methodology (MOMo) with the intention to strike a balance between modularity and quality ontology design on the one hand, and conservative backward compatibility with MODS on the other.
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- 2023
4. The $\gamma$-process nucleosynthesis in core-collapse supernovae. I. A novel analysis of $\gamma$-process yields in massive stars
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Roberti, L., Pignatari, M., Psaltis, A., Sieverding, A., Mohr, P., Fülöp, Zs., and Lugaro, M.
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Astrophysics - Solar and Stellar Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Nuclear Theory - Abstract
The $\gamma$-process nucleosynthesis in core-collapse supernovae is generally accepted as a feasible process for the synthesis of neutron-deficient isotopes beyond iron. However, crucial discrepancies between theory and observations still exist: the average production of $\gamma$-process yields from massive stars are too low to reproduce the solar distribution in galactic chemical evolution calculations, and the yields of the Mo and Ru isotopes are by a further factor of 10 lower than the yields of the other $\gamma$-process nuclei. We investigate the $\gamma$-process in 5 sets of core-collapse supernova models published in literature with initial masses 15, 20, and 25 M$_{\odot}$ at solar metallicity. We compared the $\gamma$-process overproduction factors from the different models. To highlight the possible effect of nuclear physics input, we also considered 23 ratios of two isotopes close to each other in mass, relative to their solar values. Further, we investigated the contribution of C-O shell mergers in the supernova progenitors as an additional site of the $\gamma$-process. Our analysis shows that a large scatter among the different models exists for both the $\gamma$-process integrated yields and the isotopic ratios. We found only 10 ratios that agree with their solar values, all the others differ by at least a factor of 3 from the solar values in all the considered sets of models. The $\gamma$-process within C-O shell mergers mostly influence the isotopic ratios that involve intermediate and heavy proton-rich isotopes with $\rm A>100$., Comment: Accepted for publication in A&A. 20 pages, 17 figures
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- 2023
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5. Production of $p$-nuclei from $r$-process seeds: the $\nu r$-process
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Xiong, Zewei, Martínez-Pinedo, Gabriel, Just, Oliver, and Sieverding, Andre
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Astrophysics - High Energy Astrophysical Phenomena ,Nuclear Experiment ,Nuclear Theory - Abstract
We present a new nucleosynthesis process that may take place on neutron-rich ejecta experiencing an intensive neutrino flux. The nucleosynthesis proceeds similarly to the standard $r$-process, a sequence of neutron-captures and beta-decays, however with charged-current neutrino absorption reactions on nuclei operating much faster than beta-decays. Once neutron capture reactions freeze-out the produced $r$-process neutron-rich nuclei undergo a fast conversion of neutrons into protons and are pushed even beyond the $\beta$-stability line producing the neutron-deficient $p$-nuclei. This scenario, which we denote as the $\nu r$-process, provides an alternative channel for the production of $p$-nuclei and the short-lived nucleus $^{92}$Nb. We discuss the necessary conditions posed on the astrophysical site for the $\nu r$-process to be realized in nature. While these conditions are not fulfilled by current neutrino-hydrodynamic models of $r$-process sites, future models, including more complex physics and a larger variety of outflow conditions, may achieve the necessary conditions in some regions of the ejecta., Comment: 5 pages, 4 figures, published in PRL, including the Supplemental Material
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- 2023
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6. Marital quality in a context of displacement: the role of union formation characteristics among Syrian refugee and Jordanian youth
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Torrisi, Orsola and Sieverding, Maia
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- 2024
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7. Marital quality in a context of displacement: the role of union formation characteristics among Syrian refugee and Jordanian youth
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Orsola Torrisi and Maia Sieverding
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Demography. Population. Vital events ,HB848-3697 - Abstract
Abstract Marital quality is an important determinant of well-being and is related to how unions are formed. Both processes of union formation and marital relationships may be influenced by stressful conditions, including insecurity and displacement. We leverage unique representative data on young Syrian refugees in Jordan to learn more about the interplay between displacement, union formation characteristics and marital quality. Through comparisons with youth from the Jordanian host population, we assess the role of key contextual predictors of marital quality, such as consanguinity and young people’s role in choosing their spouse, with a focus on gender differences. We measure marital quality with six separate items capturing aspects of equality, respect and interpersonal communication and a unidimensional scale identified through exploratory factor analysis. Results show that consanguinity, marital duration and number of children are generally unrelated to marital quality in both populations. In contrast, involvement in spouse choice emerges as the strongest predictor, with both Syrians and Jordanians in family-arranged unions experiencing lower-quality marriages. Among Syrians, women suffer more from lower marital quality, especially when arranged unions happen at a young age, and marriages formed after displacement to Jordan appear more fragile. The study is one of the first to explore predictors of marital quality in a non-Western, conflict-affected population. The findings emphasise the importance of the demographic study of family dynamics in situations of insecurity and displacement moving beyond a narrow focus on marriage timing to cover a wider range of marriage outcomes related to family well-being.
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- 2024
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8. Tracer particles for core-collapse supernova nucleosynthesis: The advantages of moving backward
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Sieverding, Andre, Waldrop, Preston G., Harris, J. Austin, Hix, W. Raphael, Lentz, Eric J., Bruenn, Stephen W., and Messer, O. E. Bronson
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Astrophysics - Solar and Stellar Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
After decades, the theoretical study of core-collapse supernova explosions is moving from parameterized, spherically symmetric models to increasingly realistic multi-dimensional simulations. Obtaining nucleosynthesis yields based on such multi-dimensional core-collapse supernova (CCSN) simulations, however, is not straightforward and frequently tracer particles are employed. Tracer particles may be tracked in situ during the simulation, but often they are reconstructed in a post-processing step based on the information saved during the hydrodynamics simulation. Reconstruction can be done in a number of ways and here we compare the approaches of backward and forward integration of the equations of motion to the results based on inline particle trajectories. We find that both methods agree reasonably well with the inline results for isotopes for which a large number of particles contribute. However, for rarer isotopes that are produced only by a small number of particle trajectories, deviations can be large. For our setup, we find that backward integration leads to a better agreement with the inline particles by more accurately reproducing the conditions following freeze-out from nuclear statistical equilibrium, because the establishment of nuclear statistical equilibrium erases the need for detailed trajectories at earlier times. Based on our results, if inline tracers are unavailable, we recommend backward reconstruction, to the point when nuclear statistical equilibrium last applied, with an interval between simulation snapshots of at most 1 ms for nucleosynthesis post-processing., Comment: 23 pages, 18 figures, sumitted to ApJ
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- 2022
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9. Comparison of the Core-Collapse Evolution of Two Nearly Equal Mass Progenitors
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Bruenn, Stephen W., Sieverding, Andre, Lentz, Eric J., Sukhbold, Tuguldur, Hix, W. Raphael, Huk, Leah N., Harris, J. Austin, Messer, O. E. Bronson, and Mezzacappa, Anthony
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Astrophysics - Solar and Stellar Astrophysics - Abstract
We compare the core-collapse evolution of a pair of 15.8 $M_\odot$ stars with significantly different internal structures, a consequence of bimodal variability exhibited by massive stars during their late evolutionary stages. The 15.78 and 15.79 $M_\odot $ progenitors have core masses of 1.47 and 1.78 $M_\odot$ and compactness parameters $\xi_{1.75}$ of 0.302 and 0.604. The core collapse simulations are carried out in 2D to nearly 3 s post-bounce and show substantial differences in the times of shock revival and explosion energies. The 15.78 $M_\odot$ model explodes promptly at 120 ms post-bounce when a strong density decrement at the Si--Si/O shell interface encounters the stalled shock. The 15.79 $M_\odot$ model, which lacks the density decrement, takes 100 ms longer to explode but ultimately produces a more powerful explosion. Larger mass accretion rate of the 15.79 $M_\odot$ model during the first 0.8 s post-bounce results in larger $\nu_{e}$/$\bar \nu_{e}$ luminosities and rms energies. The $\nu_{e}$/$\bar \nu_{e}$ luminosities and rms energies arising from the inner core are also larger in the 15.79 $M_\odot$ model throughout due to the larger negative temperature gradient of this core due to greater adiabatic compression. Larger luminosities and rms energies in the 15.79 $M_\odot$ model and a flatter and higher density heating region, result in more energy deposition behind the shock and more ejected matter with higher enthalpy. We find the ejected $^{56}$Ni mass of the 15.79 $M_\odot$ model is more than double that of the 15.78 $M_\odot$ model. Most of the ejecta in both models is moderately proton-rich, though counterintuitively the highest electron fraction ($Y_e=0.61$) ejecta in either model is in the less energetic 15.78 $M_\odot$ model while the lowest electron fraction ($Y_e=0.45$) ejecta in either model is in the 15.79 $M_\odot$ model., Comment: 24 pages; Accepted for publication in ApJ
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- 2022
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10. Carbon footprint of South Dakota dairy production system and assessment of mitigation options
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Naranjo, Anna M, Sieverding, Heidi, Clay, David, and Kebreab, Ermias
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Agricultural ,Veterinary and Food Sciences ,Environmental Management ,Environmental Sciences ,Climate Action ,Responsible Consumption and Production ,Animals ,Carbon Footprint ,Manure ,South Dakota ,Dairying ,Greenhouse Gases ,Milk ,Methane ,Greenhouse Effect ,General Science & Technology - Abstract
Livestock production contributes to greenhouse gas (GHG) emissions. However, there is a considerable variability in the carbon footprint associated with livestock production. Site specific estimates of GHG emissions are needed to accurately focus GHG emission reduction efforts. A holistic approach must be taken to assess the environmental impact of livestock production using appropriate geographical scale. The objective of this study was to determine baseline GHG emissions from dairy production in South Dakota using a life cycle assessment (LCA) approach. A cradle-to-farm gate LCA was used to estimate the GHG emissions to produce 1 kg of fat and protein corrected milk (FPCM) in South Dakota. The system boundary was divided into feed production, farm management, enteric methane, and manure management as these activities are the main contributors to the overall GHG emissions. The production of 1 kg FPCM in South Dakota dairies was estimated to emit 1.23 kg CO2 equivalents. The major contributors were enteric methane (46%) and manure management (32.7%). Feed production and farm management made up 14.1 and 7.2%, respectively. The estimate is similar to the national average but slightly higher than the California dairy system. The source of corn used in the dairies influences the footprint. For example, South Dakota corn had fewer GHG emissions than grain produced and transported in from Iowa. Therefore, locally and more sustainably sourced feed input will contribute to further reducing the environmental impacts. Improvements in efficiency of milk production through better genetics, nutrition animal welfare and feed production are expected to further reduce the carbon footprint of South Dakota dairies. Furthermore, anaerobic digesters will reduce emissions from manure sources.
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- 2023
11. Factors affecting farmer perceived challenges towards precision agriculture
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Wang, Tong, Jin, Hailong, and Sieverding, Heidi L.
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- 2023
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12. The role of low-lying resonances for $^{10}$Be(p,$\alpha$) reaction rate and implications for the formation of the Solar System
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Sieverding, A., Randhawa, J. S., Zetterberg, D., deBoer, R. J., Ahn, T., Mancino, R., Martinez-Pinedo, G., and Hix, W. R.
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Astrophysics - High Energy Astrophysical Phenomena - Abstract
Evidence for the presence of short-lived radioactive isotopes when the Solar System formed is preserved in meteorites, providing insights into the conditions at the birth of our Sun. A low-mass core-collapse supernova had been postulated as a candidate for the origin of $^{10}$Be, reinforcing the idea that a supernova triggered the formation of the Solar System. We present a detailed study of the production of $^{10}$Be by the $\nu$ process in supernovae, which is very sensitive to the reaction rate of the major destruction channel, $^{10}$Be(p,$\alpha$)$^{7}$Li. With data from recent nuclear experiments that show the presence of a resonant state in $^{11}$B at $\approx$~193 keV, we derive new values for the $^{10}$Be(p,$\alpha$)$^{7}$Li reaction rate which are significantly higher than previous estimates. We show that, with the new $^{10}$Be(p,$\alpha$)$^{7}$Li reaction rate, a low mass CCSN is unlikely to produce enough $^{10}$Be to explain the observed $^{10}$Be/ $^{9}$Be ratio in meteorites, even for a wide range of neutrino spectra considered in our models. These findings point towards spallation reactions induced by solar energetic particles in the early Solar System as the origin of $^{10}$Be., Comment: 12 pages, 9 Figures, 4 Tables. Submitted to Physical Review C
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- 2022
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13. Comparison between core-collapse supernova nucleosynthesis and meteoric stardust grains: investigating magnesium, aluminium, and chromium
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Hartogh, Jacqueline den, Petö, Maria K., Lawson, Thomas, Sieverding, Andre, Brinkman, Hannah, Pignatari, Marco, and Lugaro, Maria
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Astrophysics - Solar and Stellar Astrophysics - Abstract
Isotope variations of nucleosynthetic origin among Solar System's solid samples are well documented, yet the origin of these variations is still uncertain. The observed variability of \iso{54}Cr among materials formed in different regions of the proto-planetary disk has been attributed to variable amounts of presolar chromium-rich oxide (chromite) grains, which exist within the meteoritic stardust inventory and most likely originated from some type of supernova explosions. To investigate if core-collapse supernovae (CCSNe) could be the site of origin of these grains, we analyse yields of CCSN models of stars with initial mass 15, 20 and 25 M$_{\odot}$, and solar metallicity. We present an extensive abundance data set of the Cr, Mg, and Al isotopes as a function of enclosed mass. We find cases in which the explosive C-ashes produce a composition in good agreement with the observed \iso{54}Cr/\iso{52}Cr and \iso{53}Cr/\iso{52}Cr ratios as well as the \iso{50}Cr/\iso{52}Cr ratios. Taking into account that the signal at atomic mass 50 could also originate from \iso{50}Ti, the ashes of explosive He-burning also match the observed ratios. Addition of material from the He ashes (enriched in Al and Cr relative to Mg to simulate the make-up of chromite grains) to the Solar System composition may reproduce the observed correlation between Mg and Cr anomalies, while material from the C-ashes does not present significant Mg anomalies together with Cr isotopic variations. In all cases, non-radiogenic, stable Mg isotope variations dominate over the variations expected from \iso{26}Al., Comment: Accepted for publication in ApJ Data available at https://doi.org/10.5281/zenodo.5822654
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- 2022
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14. Vascular rehabilitation in children with chronic intestinal failure reduces the risk of central-line associated bloodstream infections and catheter replacements
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Hilberath, Johannes, Sieverding, Ludger, Urla, Cristian, Michel, Jörg, Busch, Andreas, Tsiflikas, Ilias, Slavetinsky, Christoph, Hartleif, Steffen, Schunn, Matthias, Winkler, Franziska, Riegger, Franziska, Fuchs, Jörg, Sturm, Ekkehard, and Warmann, Steven
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- 2024
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15. Do root interactions between wheat and non-mycorrhizal ancestral plants influence fungal activity and soil quality in an Andisol?
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Castillo, Claudia, Solano, Jaime, Aguilera, Paula, Debouzy, Sacha, Catalan, Rocio, Ruiz, Antonieta, deSouza, Pedro M., Sieverding, Ewald, and Borie, Fernando
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- 2023
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16. Gender differences in the intention to get vaccinated against COVID-19: a systematic review and meta-analysis
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Zintel, Stephanie, Flock, Charlotte, Arbogast, Anna Lisa, Forster, Alice, von Wagner, Christian, and Sieverding, Monika
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- 2023
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17. The Radioactive Nuclei $^{\textbf{26}}$Al and $^{\textbf{60}}$Fe in the Cosmos and in the Solar System
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Diehl, Roland, Lugaro, Maria, Heger, Alexander, Sieverding, Andre, Tang, Xiaodong, Li, KuoAng, Li, Ertao, Doherty, Carolyn L., Krause, Martin G. H., Wallner, Anton, Prantzos, Nikos, Brinkman, Hannah E., Hartogh, Jaqueline W. den, Wehmeyer, Benjamin, López, Andrés Yagüe, Pleintinger, Moritz M. M., Banerjee, Projjval, and Wang, Wei
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Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - Solar and Stellar Astrophysics ,Nuclear Experiment ,Nuclear Theory - Abstract
The cosmic evolution of the chemical elements from the Big Bang to the present time is driven by nuclear fusion reactions inside stars and stellar explosions. A cycle of matter recurrently re-processes metal-enriched stellar ejecta into the next generation of stars. The study of cosmic nucleosynthesis and of this matter cycle requires the understanding of the physics of nuclear reactions, of the conditions at which the nuclear reactions are activated inside the stars and stellar explosions, of the stellar ejection mechanisms through winds and explosions, and of the transport of the ejecta towards the next cycle, from hot plasma to cold, star-forming gas. Due to the long timescales of stellar evolution, and because of the infrequent occurrence of stellar explosions, observational studies are challenging. Due to their radioactive lifetime of million years, the 26Al and 60Fe isotopes are suitable to characterise simultaneously the processes of nuclear fusion reactions and of interstellar transport. We describe and discuss the nuclear reactions involved in the production and destruction of 26Al and 60Fe, the key characteristics of the stellar sites of their nucleosynthesis and their interstellar journey after ejection from the nucleosynthesis sites. We connect the theoretical astrophysical aspects to the variety of astronomical messengers, from stardust and cosmic-ray composition measurements, through observation of gamma rays produced by radioactivity, to material deposited in deep-sea ocean crusts and to the inferred composition of the first solids that have formed in the Solar System. We show that considering measurements of the isotopic ratio of 26Al to 60Fe eliminate some of the unknowns when interpreting astronomical results, and discuss the lessons learned from these two isotopes on cosmic chemical evolution., Comment: 51 pages, 44 figures; review from an ISSI workshop series; accepted for publication in PASA
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- 2021
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18. Author Correction: Integrative genetic analysis illuminates ALS heritability and identifies risk genes
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Megat, Salim, Mora, Natalia, Sanogo, Jason, Roman, Olga, Catanese, Alberto, Alami, Najwa Ouali, Freischmidt, Axel, Mingaj, Xhuljana, De Calbiac, Hortense, Muratet, François, Dirrig-Grosch, Sylvie, Dieterle, Stéphane, Van Bakel, Nick, Müller, Kathrin, Sieverding, Kirsten, Weishaupt, Jochen, Andersen, Peter Munch, Weber, Markus, Neuwirth, Christoph, Margelisch, Markus, Sommacal, Andreas, Van Eijk, Kristel R., Veldink, Jan H., Lautrette, Géraldine, Couratier, Philippe, Camuzat, Agnès, Le Ber, Isabelle, Grassano, Maurizio, Chio, Adriano, Boeckers, Tobias, Ludolph, Albert C., Roselli, Francesco, Yilmazer-Hanke, Deniz, Millecamps, Stéphanie, Kabashi, Edor, Storkebaum, Erik, Sellier, Chantal, and Dupuis, Luc
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- 2023
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19. Integrative genetic analysis illuminates ALS heritability and identifies risk genes
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Megat, Salim, Mora, Natalia, Sanogo, Jason, Roman, Olga, Catanese, Alberto, Alami, Najwa Ouali, Freischmidt, Axel, Mingaj, Xhuljana, De Calbiac, Hortense, Muratet, François, Dirrig-Grosch, Sylvie, Dieterle, Stéphane, Van Bakel, Nick, Müller, Kathrin, Sieverding, Kirsten, Weishaupt, Jochen, Andersen, Peter Munch, Weber, Markus, Neuwirth, Christoph, Margelisch, Markus, Sommacal, Andreas, Van Eijk, Kristel R., Veldink, Jan H., Lautrette, Géraldine, Couratier, Philippe, Camuzat, Agnès, Le Ber, Isabelle, Grassano, Maurizio, Chio, Adriano, Boeckers, Tobias, Ludolph, Albert C., Roselli, Francesco, Yilmazer-Hanke, Deniz, Millecamps, Stéphanie, Kabashi, Edor, Storkebaum, Erik, Sellier, Chantal, and Dupuis, Luc
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- 2023
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20. Intersecting social-ecological vulnerabilities to and lived experiences of sexually transmitted infections among Syrian refugee women in Lebanon: A qualitative study.
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Sasha Abdallah Fahme, Sara Chehab, Carmen Helen Logie, Ghina Mumtaz, Daniel Fitzgerald, Jennifer Alzos Downs, Jocelyn DeJong, and Maia Sieverding
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Public aspects of medicine ,RA1-1270 - Abstract
Conflict-affected women and girls living in protracted forced displacement settings are vulnerable to sexually transmitted infections (STIs). Yet, little is known about the risk factors for and lived experiences of STIs in complex humanitarian settings, particularly in the Middle East and North Africa, where STIs have long been understudied. This qualitative study adapts the social ecological model to characterize the multi-level risks for and lived experiences of STIs among Syrian refugee women resettled in an urban refugee camp in Beirut, Lebanon. Adopting a community-based sampling strategy, community health workers, who were refugee women from the camp, recruited and conducted in-depth interviews (IDIs) with 30 adult Syrian refugee women. Data were analyzed using an interpretative phenomenological approach and thematically organized according to the levels of the social ecological model. We identified a confluence of individual, interpersonal, community-based, and societal vulnerabilities to STIs, including extreme poverty and insecurity, patriarchal gender norms, stigma, sexual exploitation and trafficking, poor healthcare accessibility, intimate partner violence, including marital rape, transactional sex, sexual harassment, social isolation, and internalized stigma. Participants described experiencing bothersome symptoms and sequelae of advanced and untreated STIs in the setting of limited access to health services and challenges with engaging their partners in STI treatment, largely due to STI stigma. These novel findings suggest dynamic, interrelated social and health disparities across all social ecological levels influencing refugee women's sexual health, including their risk of STIs. Comprehensive, multi-sectorial interventions, which transcend traditional public health methods and which adopt a sexual well-being approach, are urgently needed to address systemic and intrapersonal violence against refugee women, examine and mitigate the burden of STIs, and ensure sexual justice and health equity in this protracted forced displacement setting.
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- 2024
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21. A Modular Ontology for MODS - Metadata Object Description Schema.
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Rushrukh Rayan, Cogan Shimizu, Heidi Sieverding, and Pascal Hitzler
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- 2023
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22. Author Correction: Integrative genetic analysis illuminates ALS heritability and identifies risk genes
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Salim Megat, Natalia Mora, Jason Sanogo, Olga Roman, Alberto Catanese, Najwa Ouali Alami, Axel Freischmidt, Xhuljana Mingaj, Hortense De Calbiac, François Muratet, Sylvie Dirrig-Grosch, Stéphane Dieterle, Nick Van Bakel, Kathrin Müller, Kirsten Sieverding, Jochen Weishaupt, Peter Munch Andersen, Markus Weber, Christoph Neuwirth, Markus Margelisch, Andreas Sommacal, Kristel R. Van Eijk, Jan H. Veldink, Project Mine Als Sequencing Consortium, Géraldine Lautrette, Philippe Couratier, Agnès Camuzat, Isabelle Le Ber, Maurizio Grassano, Adriano Chio, Tobias Boeckers, Albert C. Ludolph, Francesco Roselli, Deniz Yilmazer-Hanke, Stéphanie Millecamps, Edor Kabashi, Erik Storkebaum, Chantal Sellier, and Luc Dupuis
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Science - Published
- 2023
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23. Impact of Dark Photon Emission on Massive Star Evolution and Pre-Supernova Neutrino Signal
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Sieverding, A., Rrapaj, E., Guo, G., and Qian, Y. -Z.
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Astrophysics - Solar and Stellar Astrophysics ,High Energy Physics - Phenomenology - Abstract
We study the effects of additional cooling due to the emission of a dark matter candidate particle, the dark photon, on the final phases of the evolution of a $15\,M_\odot$ star and resulting modifications of the pre-supernova neutrino signal. For a substantial portion of the dark photon parameter space the extra cooling speeds up Si burning, which results in a reduced number of neutrinos emitted during the last day before core collapse. This reduction can be described by a systematic acceleration of the relevant timescales and the results can be estimated semi-analytically in good agreement with the numerical simulations. Outside the semi-analytic regime we find more complicated effects. In a narrow parameter range, low-mass dark photons lead to an increase of the number of emitted neutrinos because of additional shell burning episodes that delay core collapse. Furthermore, relatively strong couplings produce a thermonuclear runaway during O burning, which could result in a complete disruption of the star but requires more detailed simulations to determine the outcome. Our results show that pre-supernova neutrino signals are a potential probe of the dark photon parameter space., Comment: 14 pages, 14 figures, submitted to ApJ
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- 2021
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24. Improving Sleep Among Teachers: an Implementation-Intention Intervention
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Schmidt, Laura I., Steenbock, Lisa M., and Sieverding, Monika
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- 2023
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25. Nucleosynthesis of an $11.8\,M_\odot$ Supernova with 3D Simulation of the Inner Ejecta: Overall Yields and Implications for Short-Lived Radionuclides in the Early Solar System
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Sieverding, Andre, Mueller, Bernhard, and Qian, Yong-Zhong
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Astrophysics - High Energy Astrophysical Phenomena - Abstract
Based on a 3D supernova simulation of an $11.8\,M_\odot$ progenitor model with initial solar composition, we study the nucleosynthesis using tracers covering the innermost $0.1\,M_\odot$ of the ejecta. These ejecta are mostly proton-rich and contribute significant amounts of $^{45}$Sc and $^{64}$Zn. The production of heavier isotopes is sensitive to the electron fraction and hence the neutrino emission from the proto-neutron star. The yields of these isotopes are rather uncertain due to the approximate neutrino transport used in the simulation. In order to obtain the total yields for the whole supernova, we combine the results from the tracers with those for the outer layers from a suitable 1D model. Using the yields of short-lived radionuclides (SLRs), we explore the possibility that an $11.8\,M_\odot$ supernova might have triggered the formation of the solar system and provided some of the SLRs measured in meteorites. In particular, we discuss two new scenarios that can account for at least the data on $^{41}$Ca, $^{53}$Mn, and $^{60}$Fe without exceeding those on the other SLRs., Comment: 16 pages, 9 Figures, 4 Tables
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- 2020
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26. Potential Impact of Fast Flavor Oscillations on Neutrino-driven Winds and Their Nucleosynthesis
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Xiong, Zewei, Sieverding, Andre, Sen, Manibrata, and Qian, Yong-Zhong
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Astrophysics - High Energy Astrophysical Phenomena - Abstract
The wind driven by the intense neutrino emission from a protoneutron star (PNS) is an important site for producing nuclei heavier than the Fe group. Because of certain features in the neutrino angular distributions, the so-called fast flavor oscillations may occur very close to the PNS surface, effectively resetting the neutrino luminosities and energy spectra that drive the wind. Using the unoscillated neutrino emission characteristics from two core-collapse supernova simulations representative of relevant progenitors at the lower and higher mass end, we study the potential effects of fast flavor oscillations on neutrino-driven winds and their nucleosynthesis. We find that such oscillations can increase the total mass loss by factors up to ~ 1.5-1.7 and lead to significantly more proton-rich conditions. The latter effect can greatly enhance the production of 64Zn and the so-called light p-nuclei 74Se, 78Kr, and 84Sr. Implications for abundances in metal-poor stars, Galactic chemical evolution in general, and isotopic anomalies in meteorites are discussed., Comment: 12 pages, 7 figures, 2 tables, submitted to ApJ
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- 2020
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27. Understanding farmer views of precision agriculture profitability in the U.S. Midwest
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Wang, Tong, Jin, Hailong, Sieverding, Heidi, Kumar, Sandeep, Miao, Yuxin, Rao, Xudong, Obembe, Oladipo, Mirzakhani Nafchi, Ali, Redfearn, Daren, and Cheye, Stephen
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- 2023
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28. Integrative genetic analysis illuminates ALS heritability and identifies risk genes
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Salim Megat, Natalia Mora, Jason Sanogo, Olga Roman, Alberto Catanese, Najwa Ouali Alami, Axel Freischmidt, Xhuljana Mingaj, Hortense De Calbiac, François Muratet, Sylvie Dirrig-Grosch, Stéphane Dieterle, Nick Van Bakel, Kathrin Müller, Kirsten Sieverding, Jochen Weishaupt, Peter Munch Andersen, Markus Weber, Christoph Neuwirth, Markus Margelisch, Andreas Sommacal, Kristel R. Van Eijk, Jan H. Veldink, Project Mine Als Sequencing Consortium, Géraldine Lautrette, Philippe Couratier, Agnès Camuzat, Isabelle Le Ber, Maurizio Grassano, Adriano Chio, Tobias Boeckers, Albert C. Ludolph, Francesco Roselli, Deniz Yilmazer-Hanke, Stéphanie Millecamps, Edor Kabashi, Erik Storkebaum, Chantal Sellier, and Luc Dupuis
- Subjects
Science - Abstract
Abstract Amyotrophic lateral sclerosis (ALS) has substantial heritability, in part shared with fronto-temporal dementia (FTD). We show that ALS heritability is enriched in splicing variants and in binding sites of 6 RNA-binding proteins including TDP-43 and FUS. A transcriptome wide association study (TWAS) identified 6 loci associated with ALS, including in NUP50 encoding for the nucleopore basket protein NUP50. Independently, rare variants in NUP50 were associated with ALS risk (P = 3.71.10−03; odds ratio = 3.29; 95%CI, 1.37 to 7.87) in a cohort of 9,390 ALS/FTD patients and 4,594 controls. Cells from one patient carrying a NUP50 frameshift mutation displayed a decreased level of NUP50. Loss of NUP50 leads to death of cultured neurons, and motor defects in Drosophila and zebrafish. Thus, our study identifies alterations in splicing in neurons as critical in ALS and provides genetic evidence linking nuclear pore defects to ALS.
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- 2023
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29. Intercropping wheat with ancestral non-mycorrhizal crops in a volcanic soil at early growth stage
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Castillo, Claudia, Solano, Jaime, Collinao, Mauricio, Catalan, Rocio, Campos, Pedro, Aguilera, Paula, Sieverding, Ewald, and Borie, Fernando
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- 2022
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30. Substituting a randomised placebo control group with a historical placebo control in an endometriosis pain trial: a case study re-evaluating trial data using historical control data from another trial
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Marius Sieverding, Christoph Gerlinger, and Christian Seitz
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Medicine - Abstract
Objective The substitution of an in-study control population with a historical control (HC) population is considered a viable option for reducing the necessary recruitment of control patients. However, it is necessary to evaluate whether this method is applicable to studies on indications targeting endometriosis-associated pelvic pain (EAPP). This study aims to evaluate the potential bias in the results of an EAPP study with an HC arm.Methods For this case study, we re-evaluated data from a randomised, placebo-controlled trial using dienogest daily to treat EAPP with an HC arm based on data from a second randomised, placebo-controlled trial in the same indication. Propensity Score (PS) matching was used to match between the treatment and HC arm on all baseline variables. To evaluate the effect of matching on the introduced bias, we evaluated efficacy parameters with the full treatment and control group, as well as the matched group.Results The difference between means (placebo minus treatment) in change in pain, as measured on the Visual Analogue Scale from baseline to end of treatment, deviates in the comparison treatment/pool of HC (7.15 (0.22 to 14.08)) from the overall in-study group (reference: 11.89 (6.06 to 17.73)). After PS matching on the baseline variables, the difference between means (11.79 (4.09 to 19.5)) is close to the reference.Conclusions Using HC with PS matching has proven to be useful in the setting of treating EAPP, while emphasis must be given to the selection mechanism and the underlying assumptions. This case study has shown that even for studies which are very similar in design, heterogeneity and between-study variations are present. With the use of an HC arm, it was possible to reproduce similar results than in the original study, while the PS matching improved the comparability considerably. For the main endpoint, PS matching could reproduce the original study results.Trial registration number NCT00225199, NCT00185341
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- 2023
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31. Rate of dark photon emission from electron positron annihilation in massive stars
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Rrapaj, Ermal, Sieverding, Andre, and Qian, Yong-Zhong
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High Energy Physics - Phenomenology ,Astrophysics - Solar and Stellar Astrophysics - Abstract
We calculate the rate of production of dark photons from electron-positron pair annihilation in hot and dense matter characteristic of supernova progenitors. Given the non-linear dependence of the emission rate on the dark photon mass and current astrophysical constraints on the dark photon parameter space, we focus on the mass range of 1--10 MeV. For the conditions under consideration both mixing with the in-medium photon and plasma effects on the electron dispersion relation are non-negligible and are explored in detail. We perform our calculations to the leading order in the fine-structure constant. Transverse and longitudinal photon modes are treated separately given their different dispersion relations. We consider the implications for the evolution of massive stars when dark photons decay either into particles of the standard model or of the dark sector., Comment: 6 pages, 4 figures
- Published
- 2019
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32. The $\nu$-process with fully time-dependent supernova neutrino emission spectra
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Sieverding, Andre, Martínez-Pinedo, Gabriel, Langanke, Karlheinz, Bollig, Robert, Janka, Hans-Thomas, and Heger, Alexander
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Astrophysics - High Energy Astrophysical Phenomena - Abstract
The neutrino process that occurs in the outer stellar shells during a supernova explosion and involves neutrino-nucleus reactions produces a range of rare, stable and radioactive isotopes. We improve previous $\nu$-process studies by using, for the first time, the time-dependent neutrino emission spectra, as predicted from supernova simulations, rather than a simplified parametric description modeled after the neutron-star cooling phase. In particular, our calculations use time-dependent neutrino spectra for all neutrino species, consider their deviation from a Fermi-Dirac distribution and account for the neutrino emission from the neutrino burst and accretion phases. We find that the time-dependent treatment of the neutrino emission spectra results in higher yields for the selected nuclei produced by the $\nu$~process as compared to previous studies and also compared to the approximation of assuming constant neutrino energies corresponding to the time-averaged mean energy radiated in each species. The effect is largest for nuclides produced by charged-current reactions. Our results reflect the dynamical competition between neutrino-induced reactions and the effect of the shock passage through the star. By varying the neutrino burst luminosity and the duration of the accretion phase, we study the impact of these early emission phases and their uncertainties on the $\nu$-process nucleosynthesis. We find that the deviation of the neutrino spectra from a Fermi-Dirac distribution calculated in supernova simulations has a negligible effect on the $\nu$-process yields., Comment: 16 pages, 8 figures, 2 tables, submitted to the Astrophysical Journal
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- 2019
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33. Neutrino nucleosynthesis: An overview
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Langanke, Karlheinz, Martinez-Pinedo, Gabriel, and Sieverding, Andre
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Astrophysics - High Energy Astrophysical Phenomena ,Nuclear Theory - Abstract
Neutrinos produced during a supernova explosion induce reactions on abundant nuclei in the outer stellar shells and contribute in this way to the synthesis of the elements in the Universe. This neutrino nucleosynthesis process has been identified as an important contributor to the origin of $^7$Li, $^{11}$B,$^{19}$F, $^{138}$La, and $^{180}$Ta, but also to the long-lived radionuclides $^{22}$Na and $^{26}$Al, which are both key isotopes for $\gamma$-ray astronomy. The manuscript summarizes the recent progress achieved in simulations of neutrino nucleosynthesis., Comment: 7 pages, 2 figures
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- 2019
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34. Mass Measurements of Neutron-Rich Gallium Isotopes Refine Production of Nuclei of the First r-Process Abundance Peak in Neutron Star Merger Calculations
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Reiter, M. P., Andrés, S. Ayet San, Nikas, S., Lippuner, J., Andreoiu, C., Babcock, C., Barquest, B. R., Bollig, J., Brunner, T., Dickel, T., Dilling, J., Dillmann, I., Dunling, E., Gwinner, G., Graham, L., Hornung, C., Klawitter, R., Kootte, B., Kwiatkowski, A. A., Lan, Y., Lascar, D., Leach, K. G., Leistenschneider, E., Martínez-Pinedo, G., McKay, J. E., Paul, S. F., Plaß, W. R., Roberts, L., Schatz, H., Scheidenberger, C., Sieverding, A., Steinbrügge, R., Thompson, R., Wieser, M. E., Will, C., and Welch, D.
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Nuclear Experiment ,Astrophysics - High Energy Astrophysical Phenomena ,Nuclear Theory - Abstract
We report mass measurements of neutron-rich Ga isotopes $^{80-85}$Ga with TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN). The measurements determine the masses of $^{80-83}$Ga in good agreement with previous measurements. The masses of $^{84}$Ga and $^{85}$Ga were measured for the first time. Uncertainties between $25-48$ keV were reached. The new mass values reduce the nuclear uncertainties associated with the production of A $\approx$ 84 isotopes by the \emph{r}-process for astrophysical conditions that might be consistent with a binary neutron star (BNS) merger producing a blue kilonova. Our nucleosynthesis simulations confirm that BNS merger may contribute to the first abundance peak under moderate neutron-rich conditions with electron fractions $Y_e=0.35-0.38$.
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- 2018
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35. The effects of political protests on youth human capital and well-being in Egypt
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Liu, Jenny, Modrek, Sepideh, and Sieverding, Maia
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Economics ,Applied Economics ,Human Society ,Clinical Research ,Pediatric ,Behavioral and Social Science ,Basic Behavioral and Social Science ,Good Health and Well Being ,Peace ,Justice and Strong Institutions ,Adolescent ,Adolescent Behavior ,Adult ,Child ,Child Behavior ,Civil Disorders ,Egypt ,Female ,Health Status ,Humans ,Male ,Politics ,Young Adult ,Human capital ,Mental health ,Young adults ,Transition to adulthood ,Political protests ,Medical and Health Sciences ,Studies in Human Society ,Public Health ,Health sciences ,Human society - Abstract
Protests are one of the most common expressions of modern political conflict, and the wave of demonstrations that marked the onset of the Arab Spring contributed to a global increase in protest activity. Yet few studies have examined the effects of exposure to protests on population well-being even though such exposure may have profound and lasting effects, especially if experienced at critical stages of development over the life course. The aim of our study is to estimate the effects of exposure to political protests on the human capital accumulation and well-being of youth during the tumultuous political transition experienced in Egypt from 2011 to 2014. For a nationally representative panel of youth captured in the 2009 and 2013/2014 waves of the Survey of Young People in Egypt (SYPE), we exploit exogenous geospatial variation in the occurrence of political protests from the Armed Conflict Location & Event Data (ACLED) Project to estimate individual-level changes in social trust, uncertainty, education, and health outcomes for youth exposed to protests. In our panel, 31.1% of the sample lived in districts where riots or protests occurred. Exposure to protests increased overall perceptions of uncertainty about the future. Young men ever exposed to protests were slightly more likely to report good overall health, but experienced sizable worsening in mental health compared to young women ever exposed. Differences by own and family participation in protest events were found for perceptions of uncertainty and mental health. In the aftermath of the Arab Spring and other mass protest movements around the globe, these findings highlight the importance of examining the population-level impacts of different forms of political conflict, particularly as substantial numbers of youth in Middle East and North Africa and elsewhere progress to adulthood under conditions of political instability.
- Published
- 2019
36. Understanding farmers’ perception of extreme weather events and adaptive measures
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Etumnu, Chinonso, Wang, Tong, Jin, Hailong, Sieverding, Heidi L., Ulrich-Schad, Jessica D., and Clay, David
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- 2023
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37. Using wearables to promote physical activity in old age: Feasibility, benefits, and user friendliness
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Schmidt, Laura I., Jansen, Carl-Philipp, Depenbusch, Johanna, Gabrian, Martina, Sieverding, Monika, and Wahl, Hans-Werner
- Published
- 2022
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38. An investigation of Jordan’s fertility stall and resumed decline : The role of proximate determinants
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Krafft, Caroline, Kula, Elizabeth, and Sieverding, Maia
- Published
- 2021
39. Thoracic lymphatic anomalies in patients with univentricular hearts: correlation of morphologic findings in isotropic T2-weighted MRI with the outcome after fontan palliation
- Author
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Anja Hanser, Michael Hofbeck, Melanie Hofmeister, Petros Martirosian, Andreas Hornung, Michael Esser, Fritz Schick, Renate Kaulitz, Jörg Michel, Konstantin Nikolaou, Jürgen Schäfer, Christian Schlensak, and Ludger Sieverding
- Subjects
TCPC ,fontan circulation ,thoracic and cervical lymphatic abnormalities ,T2-weighted CMR ,univentricular cardiac disease ,failing fontan circulation ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
ObjectivesIn this study we examined the correlation between the extent of thoracic lymphatic anomalies in patients after surgical palliation by total cavopulmonary connection (TCPC) and their outcome in terms of clinical and laboratory parameters.Materials and methodsWe prospectively examined 33 patients after TCPC with an isotropic heavily T2-weighted MRI sequence on a 3.0 T scanner. Examinations were performed after a solid meal, slice thickness of 0.6 mm, TR of 2400 ms, TE of 692 ms, FoV of 460 mm, covering thoracic and abdominal regions. Findings of the lymphatic system were correlated with clinical and laboratory parameters obtained at the annual routine check-up.ResultsEight patients (group 1) showed type 4 lymphatic abnormalities. Twentyfive patients (group 2) presented less severe anomalies (type 1–3). In the treadmill CPET, group 2 reached step 7.0;6.0/8.0 vs. 6.0;3.5/6.8 in group 1 (p = 0.006*) and a distance of 775;638/854 m vs. 513;315/661 m (p = 0.006*). In the laboratory examinations, group 2 showed significantly lower levels of AST, ALT and stool calprotectin as compared to group 1. There were no significant differences in NT-pro-BNP, total protein, IgG, lymphocytes or platelets, but trends. A history of ascites showed 5/8 patients in group 1 vs. 4/25 patients in group 2 (p = 0.02*), PLE occurred in 4/8 patient in group 1 vs. 1/25 patients in group 2 (p = 0.008*).ConclusionIn the long-term follow-up after TCPC, patients with severe thoracic and cervical lymphatic abnormalities showed restrictions in exercise capacity, higher liver enzymes and an increased rate of symptoms of imminent Fontan-failure such as ascites and PLE.
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- 2023
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40. Carbon supply elasticity and determinants of farmer carbon farming decisions
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Wang, Tong, primary, Jin, Hailong, additional, Clay, David, additional, Sieverding, Heidi L., additional, and Cheye, Stephen, additional
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- 2024
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41. Production of p Nuclei from r -Process Seeds: The νr Process
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Xiong, Zewei, primary, Martínez-Pinedo, Gabriel, additional, Just, Oliver, additional, and Sieverding, Andre, additional
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- 2024
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42. Understanding farmers’ adoption of diversified crop rotations in South Dakota, USA: an examination of the roles of sense of place and social responsibility
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Avemegah, Edem, primary, Bennett, Elizabeth A., additional, Ulrich-Schad, Jessica D., additional, Wang, Tong, additional, Eaton, Weston M., additional, Sieverding, Heidi L., additional, Westhoff, Shaina, additional, and Clay, David E., additional
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- 2024
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43. Assessing the Impact of Community Center Interventions on Social Cohesion in Conflict-Affected Areas of Tripoli
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Addam, Ahmad, primary and Sieverding, Maia, additional
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- 2024
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44. Impact and Determinants of Structural Barriers on Physical Activity in People with Cancer
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Depenbusch, Johanna, Wiskemann, Joachim, Haussmann, Alexander, Tsiouris, Angeliki, Schmidt, Laura, Ungar, Nadine, Sieverding, Monika, and Steindorf, Karen
- Published
- 2022
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45. The $\nu$ process in the light of an improved understanding of supernova neutrino spectra
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Sieverding, A., Martínez-Pinedo, G., Huther, L., Langanke, K., and Heger, A.
- Subjects
Astrophysics - High Energy Astrophysical Phenomena ,Nuclear Theory - Abstract
We study the neutrino-induced production of nuclides in explosive supernova nucleosynthesis for progenitor stars with solar metallicity including neutrino nucleus reactions for all nuclei with charge numbers $Z < 76$ with average neutrino energies in agreement with modern Supernova simulations. Considering progenitors with initial main sequence masses between 13~M$_\odot$ and 30~M$_\odot$, we find a significant production of $^{11}$B, $^{138}$La, and $^{180}$Ta by neutrino nucleosynthesis, despite the significantly reduced neutrino energies. The production of $^{19}$F turns out to be more sensitive to the progenitor mass and structure than to the $\nu$ process. With our complete set of cross sections we have identified effects of the $\nu$~process on several stable nuclei including $^{33}$S, $^{40}$Ar, $^{41}$K, $^{59}$Co, and $^{113}$In at the 10\% level. Neutrino-induced reactions contribute to a similar extent to the production of radioactive ${}^{26}$Al and increase the yield of $^{22}$Na by 50\%. Future $\gamma$~ray astronomy missions may reach the precision at which the contribution from the $\nu$~process becomes relevant. We find that the production of $^{22}$Na by the $\nu$~process could explain the Ne-E(L) component of meteoritic graphite grains. The $\nu$~process enhances the yield of $^{36}$Cl and we point out that the resulting $^{36}$Cl/$^{35}$Cl ratio is in agreement with the values infrerred for the early solar system. Our extended set of neutrino-nucleus interactions also allows us to exclude any further effects of the $\nu$ process on stable nuclei and to quantify the effects on numerous, hitherto unconsidered radioactive nuclei, e.g., $^{36}$Cl, $^{72}$As, $^{84}$Rb, and $^{88}$Y., Comment: 18 pages, 14 figures, 3 tables; submitted to ApJ
- Published
- 2018
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46. Mass Measurements of Neutron-Deficient Y, Zr, and Nb Isotopes and Their Impact on $rp$ and $\nu p$ Nucleosynthesis Processes
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Xing, Y. M., Li, K. A., Zhang, Y. H., Zhou, X. H., Wang, M., Litvinov, Yu. A., Blaum, K., Wanajo, S., Kubono, S., Martínez-Pinedo, G., Sieverding, A., Chen, R. J., Shuai, P., Fu, C. Y., Yan, X. L., Huang, W. J., Xu, X., Tang, X. D., Xu, H. S., Bao, T., Chen, X. C., Gao, B. S., He, J. J., Lam, Y. H., Li, H. F., Liu, J. H., Ma, X. W., Mao, R. S., Si, M., Sun, M. Z., Tu, X. L., Wang, Q., Yang, J. C., Yuan, Y. J., Zeng, Q., Zhang, P., Zhou, X., Zhan, W. L., Litvinov, S., Audi, G., Uesaka, T., Yamaguchi, Y., Yamaguchi, T., Ozawa, A., Fröhlich, C., Rauscher, T., Thielemann, F. -K., Sun, B. H., Sun, Y., Dai, A. C., and Xu, F. R.
- Subjects
Nuclear Experiment ,Astrophysics - Solar and Stellar Astrophysics - Abstract
Using isochronous mass spectrometry at the experimental storage ring CSRe in Lanzhou, the masses of $^{82}$Zr and $^{84}$Nb were measured for the first time with an uncertainty of $\sim 10$ keV, and the masses of $^{79}$Y, $^{81}$Zr, and $^{83}$Nb were re-determined with a higher precision. %The latter differ significantly from their literature values. The latter are significantly less bound than their literature values. Our new and accurate masses remove the irregularities of the mass surface in this region of the nuclear chart. Our results do not support the predicted island of pronounced low $\alpha$ separation energies for neutron-deficient Mo and Tc isotopes, making the formation of Zr-Nb cycle in the $rp$-process unlikely. The new proton separation energy of $^{83}$Nb was determined to be 490(400)~keV smaller than that in the Atomic Mass Evaluation 2012. This partly removes the overproduction of the $p$-nucleus $^{84}$Sr relative to the neutron-deficient molybdenum isotopes in the previous $\nu p$-process simulations.
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- 2018
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47. #Fighteverycrisis: A psychological perspective on motivators of the support of mitigation measures in the climate crisis and the COVID-19 pandemic
- Author
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Wallis, Hannah, Sieverding, Theresa, Schmidt, Karolin, and Matthies, Ellen
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- 2022
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48. Interventional closure of a bronchopleural fistula in a 2 year old child with detachable coils
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Winfried Baden, Michael Hofbeck, Steven W. Warmann, Juergen F. Schaefer, and Ludger Sieverding
- Subjects
Pneumonia ,Pleural empyema ,Bronchopleural fistula ,Coil occlusion ,Interventional bronchoscopy ,Pediatrics ,RJ1-570 - Abstract
Abstract Background Bronchopleural fistula (BPF) is a severe complication following pneumonia or pulmonary surgery, resulting in persistent air leakage (PAL) and pneumothorax. Surgical options include resection, coverage of the fistula by video-assisted thoracoscopic surgery (VATS), or pleurodesis. Interventional bronchoscopy is preferred in complex cases and involves the use of sclerosants, sealants and occlusive valve devices. Case presentation A 2.5-year-old girl was admitted to our hospital with persistent fever, cough and dyspnoea. Clinical and radiological examination revealed right-sided pneumonia and pleural effusion. The child was started on antibiotics, and the effusion was drained by pleural drainage. Following removal of the chest tube, the child developed tension pneumothorax. Despite insertion of a new drain, the air leak persisted. Thoracoscopic debridement with placement of another new drain was performed after 4 weeks, without abolishment of the air leak. Bronchoscopy with bronchography revealed a BPF in right lung segment 3 (right upper-lobe anterior bronchus). We opted for an interventional approach that was performed under general anaesthesia during repeat bronchoscopy. Following bronchographic visualisation of the fistula, a 2.7 French microcatheter was placed in right lung segment 3 (upper lobe), allowing occlusion of the fistula by successive implantation of 4 detachable high-density packing volume coils, which were placed into the fistula. Subsequent bronchography revealed no evidence of residual leakage, and the chest tube was removed 2 days later. The chest X-ray findings normalized, and follow-up over 4 years was uneventful. Conclusions Bronchoscopic superselective occlusion of BPF using detachable high-density packing large-volume coils was a successful minimally invasive therapeutic intervention performed with minimal trauma in this child and has not been reported thus far. In our small patient, the short interventional time, localized intervention and minimal damage in the lung seemed superior to the corresponding outcomes of surgical lobectomy or pleurodesis in a young growing lung, enabling normal development of the surrounding tissue. Follow-up over 4 years did not show any side effects and was uneventful, with normal lung-function test results to date.
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- 2022
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49. Introducing the subcutaneous depot medroxyprogesterone acetate injectable contraceptive via social marketing: lessons learned from Nigeria's private sector.
- Author
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Liu, Jenny, Schatzkin, Eric, Omoluabi, Elizabeth, Fajemisin, Morenike, Onuoha, Chidinma, Erinfolami, Temitope, Ayodeji, Kazeem, Ogunmola, Saliu, Shen, Jennifer, Diamond-Smith, Nadia, and Sieverding, Maia
- Subjects
Humans ,Contraceptive Agents ,Female ,Injections ,Subcutaneous ,Contraception Behavior ,Private Sector ,Social Marketing ,Adult ,Delivery of Health Care ,Nigeria ,Female ,Young Adult ,Medroxyprogesterone Acetate ,Community-based distribution ,Injectable contraceptive ,Private sector ,Social marketing ,Subcutaneous depot medroxyprogesterone acetate ,Clinical Research ,Basic Behavioral and Social Science ,Health Services ,Behavioral and Social Science ,Good Health and Well Being ,Clinical Sciences ,Paediatrics and Reproductive Medicine ,Public Health and Health Services ,Obstetrics & Reproductive Medicine - Abstract
ObjectivesThe subcutaneous depot medroxyprogesterone acetate (DMPA-SC) injectable contraceptive was introduced in South West Nigeria in 2015 through private sector channels. The introduction included community-based distribution and was supported by a social marketing approach. From program monitoring and evaluation, aimed at understanding performance, market reach and other process measures, we identify lessons learned to inform future scale-up efforts.MethodsWe synthesized the findings from a core set of key performance indicators collected through different methods: (1) implementer performance indicators, (2) phone survey of DMPA-SC users (n=541) with a follow-up after 3 months (n=342) and (3) in-depth interviews with 57 providers and 42 users of DMPA-SC.ResultsDistribution of DMPA-SC to private providers was concentrated in states with large urban populations. A shift toward focusing on high-volume family planning facilities coincided with a rapid increase in distribution in late 2016. Users reached in the phone survey were generally older and married with children; few were under age 25. Users and providers reported favorable opinions of DMPA-SC. Many users reported choosing DMPA-SC due to recommendations from providers and friends, and the hope of experiencing reduced side effects compared to other methods. While users reported positive experiences interacting with community-based distributors, the delivery model encountered a number of challenges - high turnover, low motivation, lack of an appropriate compensation package and logistical costs - and was ultimately disbanded.ConclusionsIn the DMPA-SC introductory program in Nigeria, distribution was amplified when focused on high-volume contraceptive providers. Although community-based distribution can be one effective service delivery model for reaching underserved populations, more consideration for balancing cost recovery and public health goals through private sector approaches are needed in the context of South West Nigeria. Additional communications and outreach efforts are needed to reach younger, unmarried users with contraceptive services.
- Published
- 2018
50. Production of 44Ti and Iron-group Nuclei in the Ejecta of 3D Neutrino-driven Supernovae
- Author
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Andre Sieverding, Daniel Kresse, and Hans-Thomas Janka
- Subjects
Core-collapse supernovae ,Supernova remnants ,Gamma-ray sources ,Explosive nucleosynthesis ,Nucleosynthesis ,Astrophysics ,QB460-466 - Abstract
The radioactive isotopes ^44 Ti and ^56 Ni are important products of explosive nucleosynthesis, which play a key role in supernova (SN) diagnostics and have been detected in several nearby young SN remnants. However, most SN models based on nonrotating single stars predict yields of ^44 Ti that are much lower than the values inferred from observations. We present, for the first time, the nucleosynthesis yields from a self-consistent three-dimensional SN simulation of a ∼19 M _⊙ progenitor star that reaches an explosion energy comparable to that of SN 1987A and that covers the evolution of the neutrino-driven explosion until more than 7 s after core bounce. We find a significant enhancement of the Ti/Fe yield compared to recent spherically symmetric (1D) models and demonstrate that the long-time evolution is crucial to understanding the efficient production of ^44 Ti due to the nonmonotonic temperature and density history of the ejected material. Additionally, we identify characteristic signatures of the nucleosynthesis in proton-rich ejecta, in particular high yields of ^45 Sc and ^64 Zn.
- Published
- 2023
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- View/download PDF
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