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14,282 results on '"T. Lehmann"'

12. Findings from T. Lehmann and Co-Researchers in the Area of Arthropod Structure and Development Described [The visual system of Thelyphonida (whip scorpions): Support for Arachnopulmonata]

Subjects
Architecture, Phylogeny, Editors, Social science research, Biological sciences, Health
Abstract

2019 JUN 25 (NewsRx) -- By a News Reporter-Staff News Editor at Life Science Weekly -- Current study results on Life Science Research - Arthropod Structure and Development have been [...]

Published
2019

16. Factors influencing GPs’ perception of specialised palliative homecare (SPHC) importance – results of a cross-sectional study

Author

K. Stichling, M. Krause, B. Ditscheid, M. Hach, M. Jansky, M. Kaufmann, T. Lehmann, W. Meißner, F. Nauck, W. Schneider, S. Schulz, H. C. Vollmar, U. Wedding, J. Bleidorn, A. Freytag, and the SAVOIR Study Group

Subjects
General practice, Primary palliative care, Specialised palliative homecare, Home care service, Surveys and questionnaires, Cross-sectional survey, Special situations and conditions, RC952-1245
Abstract

Abstract Background General Practitioners (GPs) are the main providers of primary palliative care (PPC). At the same time they are the main initiators of specialised palliative homecare (SPHC). In Germany, little is known about factors which influence GPs in their involvement of SPHC. Aim of our study is to identify factors that drive GPs to give value to and involve SPHC. Methods A cross-sectional survey was performed. In 2018, questionnaires were mailed to 6000 randomly selected GPs from eight German federal states, focusing on the extent of GPs’ palliative care activities and their involvement of SPHC. Results With a response rate of 19.4% and exclusion of GPs working in SPHC-teams, n = 1026 questionnaires were appropriate for analysis. GPs valued SPHC support as the most “important/very important” for both “technical/invasive treatment measures” (95%) and availability outside practice opening hours (92%). The most relevant factor influencing perceived SPHC-importance was GPs’ self-reported extent of engagement in palliative care (β = − 0.283; CI 95% = − 0.384;−0.182), followed by the perceived quality of utilised SPHC (β = 0.119; CI 95% = 0.048;0.190), involvement in treatment of palliative patients after SPHC initiation (β = 0.088; CI 95% = 0.042;0.134), and conviction that palliative care should be a central part of GPs’ work (β = − 0.062; CI 95% = − 0.116;−0.008). Perceived SPHC-importance is also associated with SPHC-referrals (β =0.138; p

Published
2020
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19. Does Pentaerytrithyltetranitrate reduce fetal growth restriction in pregnancies complicated by uterine mal-perfusion? Study protocol of the PETN-study: a randomized controlled multicenter-trial

Author

T. Groten, T. Lehmann, E. Schleußner, and for the PETN Study Group

Subjects
Fetal growth restriction, Abnormal uterine Doppler, Nitric oxide (NO-) donors, Pentaerytrithyltetranitrate (PETN), Perinatal death, Gynecology and obstetrics, RG1-991
Abstract

Abstract Background Affecting approximately 10% of pregnancies, fetal growth restriction (FGR), is the most important cause of perinatal mortality and morbidity. Impaired placental function and consequent mal-perfusion of the placenta is the leading cause of FGR. Although, screening for placental insufficiency based on uterine artery Doppler measurement is well established, there is no treatment option for pregnancies threatened by FGR. The organic nitrate pentaerithrityl tetranitrate (PETN) is widely used for the treatment of cardiovascular disease and has been shown to have protective effects on human endothelial cells. In a randomized placebo controlled pilot-study our group could demonstrate a risk reduction of 39% for the development of FGR, and FGR or death, by administering PETN to patients with impaired uterine artery Doppler at mid gestation. To confirm these results a prospective randomized placebo controlled double-blinded multicentre trial was now initiated. Method The trial has been initiated in 14 centres in Germany. Inclusion criteria are abnormal uterine artery Doppler, defined by mean PI > 1.6, at 190 to 226 weeks of gestation in singleton pregnancies. Included patients will be monitored in 4-week intervals. Primary outcome measures are development of FGR (birth weight

Published
2019
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22. Mycobacterium tuberculosis Affects Protein and Lipid Content of Circulating Exosomes in Infected Patients Depending on Tuberculosis Disease State

Author

Fantahun Biadglegne, Johannes R. Schmidt, Kathrin M. Engel, Jörg Lehmann, Robert T. Lehmann, Anja Reinert, Brigitte König, Jürgen Schiller, Stefan Kalkhof, and Ulrich Sack

Subjects
exosomes, lipids, proteins, Mycobacterium tuberculosis, plasma, tuberculosis, Biology (General), QH301-705.5
Abstract

Tuberculosis (TB), which is caused by the bacterium Mycobacterium tuberculosis (Mtb), is still one of the deadliest infectious diseases. Understanding how the host and pathogen interact in active TB will have a significant impact on global TB control efforts. Exosomes are increasingly recognized as a means of cell-to-cell contact and exchange of soluble mediators. In the case of TB, exosomes are released from the bacillus and infected cells. In the present study, a comprehensive lipidomics and proteomics analysis of size exclusion chromatography-isolated plasma-derived exosomes from patients with TB lymphadenitis (TBL) and treated as well as untreated pulmonary TB (PTB) was performed to elucidate the possibility to utilize exosomes in diagnostics and knowledge building. According to our findings, exosome-derived lipids and proteins originate from both the host and Mtb in the plasma of active TB patients. Exosomes from all patients are mostly composed of sphingomyelins (SM), phosphatidylcholines, phosphatidylinositols, free fatty acids, triacylglycerols (TAG), and cholesterylesters. Relative proportions of, e.g., SMs and TAGs, vary depending on the disease or treatment state and could be linked to Mtb pathogenesis and dormancy. We identified three proteins of Mtb origin: DNA-directed RNA polymerase subunit beta (RpoC), Diacyglycerol O-acyltransferase (Rv2285), and Formate hydrogenase (HycE), the latter of which was discovered to be differently expressed in TBL patients. Furthermore, we discovered that Mtb infection alters the host protein composition of circulating exosomes, significantly affecting a total of 37 proteins. All TB patients had low levels of apolipoproteins, as well as the antibacterial proteins cathelicidin, Scavenger Receptor Cysteine Rich Family Member (SSC5D), and Ficolin 3 (FCN3). When compared to healthy controls, the protein profiles of PTB and TBL were substantially linked, with 14 proteins being co-regulated. However, adhesion proteins (integrins, Intercellular adhesion molecule 2 (ICAM2), CD151, Proteoglycan 4 (PRG4)) were shown to be more prevalent in PTB patients, while immunoglobulins, Complement component 1r (C1R), and Glutamate receptor-interacting protein 1 (GRIP1) were found to be more abundant in TBL patients, respectively. This study could confirm findings from previous reports and uncover novel molecular profiles not previously in focus of TB research. However, we applied a minimally invasive sampling and analysis of circulating exosomes in TB patients. Based on the findings given here, future studies into host–pathogen interactions could pave the way for the development of new vaccines and therapies.

Published
2022
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24. Studies from T. Lehmann and Co-Researchers Yield New Data on Neurons

Subjects
Neurons -- Reports, Biological sciences, Health
Abstract

A new study, 'Wiring a periscope--ocelli, retinula axons, visual neuropils and the ancestrality of sea spiders,' is now available. 'The Pycnogonida or sea spiders are cryptic, eight-legged arthropods with four [...]

Published
2012

27. The Konservat-Lagerstätte Menat (Paleocene; France) – an overview and new insights

Author

S. WEDMANN, D. UHL, T. LEHMANN, R. GARROUSTE, A. NEL, B. GOMEZ, K. SMITH, and S. F.K. SCHAAL

Subjects
Menat, Paleocene, Konservat-Lagerstätte, Plants, Insects, Vertebrates, Science, Geology, QE1-996.5
Abstract

The Konservat-Lagerstätte Menat (Puy-de-Dôme, France) is an outstanding archive of a Paleocene ecosystem, which was deposited in a former maar lake. Excavations during the last century have yielded an extensive flora and fauna record, therefore an overview of the current state of paleontological investigations is given in this paper. Additionally, new results based on excavations from the years 2012 to 2014 are presented. The preservation of organic matter differed strongly between excavation sites, probably influenced by weathering processes. The stratigraphic succession consists mostly of organic-rich clays, intercalated with hard, silicified claystones. In 2013 and 2014 both impression and compression fossils were collected from different outcrops. Compression fossils from organic-rich clays were exceptionally well-preserved and included three-dimensional plant remains. A new database on insect paleobiodiversity was compiled. The occurrence of charcoal in almost all horizons investigated suggests that paleowildfires were frequent during the Paleocene in the vicinity of the paleolake. The results confirm the high potential of the Konservat-Lagerstätte Menat for future paleontological research.

Published
2018

29. Logistics and maintenance research activities for DONES facility

Author

F. Arranz, T. Lehmann, F. Rauscher, G. Fischer, S. Koehler, J. Garrido, M. Rouret, and D. Sanchez-Herranz

Subjects
Nuclear Energy and Engineering, Maintenance, Mechanical Engineering, Intralogistics simulation, General Materials Science, DONES, Logistics, ddc:620, Engineering & allied operations, Civil and Structural Engineering
Abstract

DONES is planned to operate on a continuous basis with only two beam stop periods per year for maintenance. The planned operational availability is 70 %, which calls for a carefully analyzed preventive maintenance. The purpose of the research is to propose a realistic and comprehensive logistics and maintenance plan. All the maintenance activities are included in a Maintenance Matrix based on the Plant Breakdown Structure of the project. This is the basis for the creation of a maintenance plan that will lead to a Work Schedule. Special mention within this matrix will be given to those Maintenance operations that must be included in order to comply with regulation. The need of replacement of components impose some requirements on the dimensions of architec tural features of the main building such as doors, airlocks, corridors and shipping bays. To enable these re placements, the flow of materials has been developed and analyzed by an intralogistics simulation with AnyLogic. The results of this simulation lead to modifications on either the building or the components such that the replacements are feasible. The periodic replacement of an activated component has been analyzed using FMEA methodology resulting in proposals for the plant equipment designers as well as the remote handling equipment designers. Virtual reality simulations are used for a staged approach to the maintenance operation. The simulation of the HEBT scraper helped to define in detail each step or the maintenance operation. This tool has proven to be very useful to prompt changes in both the plant equipment design and the remote handling equipment. Also, the procedure of the operation itself can be refined and optimized. The conclusion of the research activities is the contribution to the definition of the building, plant equipment and achievement of the target availability., European Commission 101052200

Published
2023

33. The SPIRou legacy survey

Author

P. Fouqué, E. Martioli, J.-F. Donati, L. T. Lehmann, B. Zaire, S. Bellotti, E. Gaidos, J. Morin, C. Moutou, P. Petit, S. H. P. Alencar, L. Arnold, É. Artigau, T.-Q. Cang, A. Carmona, N. J. Cook, P. Cortés-Zuleta, P. I. Cristofari, X. Delfosse, R. Doyon, G. Hébrard, L. Malo, C. Reylé, and C. Usher

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, FOS: Physical sciences, Astronomy and Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics - Earth and Planetary Astrophysics
Abstract

Context. The rotation period of stars is an important parameter together with mass, radius, and effective temperature. It is an essential parameter for any radial velocity monitoring, as stellar activity can mimic the presence of a planet at the stellar rotation period. Several methods exist to measure it, including long sequences of photometric measurements or temporal series of stellar activity indicators. Aims. Here, we use the circular polarization in near-infrared spectral lines for a sample of 43 quiet M dwarfs and compare the measured rotation periods to those obtained with other methods. Methods. From Stokes V spectropolarimetric sequences observed with SPIRou at the Canada-France-Hawaii Telescope and the data processed with the APERO pipeline, we computed the least-squares deconvolution profiles using different masks of atomic stellar lines with known Landé factor appropriate to the effective temperature of the star. We derived the longitudinal magnetic field to examine its possible variation in 50 to 200 observations of each star. To determine the stellar rotation period, we applied a Gaussian process regression, enabling us to determine the rotation period of stars with evolving longitudinal field. Results. We were able to measure a rotation period for 27 of the 43 stars of our sample. The rotation period was previously unknown for 8 of these stars. Our rotation periods agree well with periods found in the literature based on photometry and activity indicators, and we confirm that near-infrared spectropolarimetry is an important tool for measuring rotation periods, even for magnetically quiet stars. Furthermore, we computed the ages for 20 stars of our sample using gyrochronology.

Published
2023
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34. Plio-Pleistocene aardvarks (Mammalia, Tubulidentata) from East Africa

Author

T. Lehmann

Subjects
Paleontology, QE701-760
Abstract

The Tubulidentata are unique among mammals for being the only order represented nowadays by a single living species, Orycteropus afer: the aardvark. Nevertheless, it is one of the least studied mammalian orders. Aardvarks are currently distributed all over sub-Saharan Africa, but the fossil record extends their spatial range to Europe and Asia. The earliest known Tubulidentata are ca. 20 million years old. About 14 species and three to four genera have been recognised so far, but since the late Pliocene, aardvarks have only been represented by a single genus and are restricted to Africa. The extant aardvark is the only species of Tubulidentata with a large distribution area, i.e. the African continent. There are three known Plio-Pleistocene African species of aardvark: Orycteropus afer (Pallas, 1766), O. crassidens MacInnes, 1956, and O. djourabensis Lehmann et al., 2004. Fossils of these species have been discovered in North-Africa, Kenya, and Chad respectively. The present study is focused on the aardvark material found in the Plio-Pleistocene of East Africa (Ethiopia, Kenya). New specimens from Asa Issie (Ethiopia) and East Turkana (Kenya) are described, and published ones are re-examined in the light of the latest discoveries. This study demonstrates that Kenyan specimens identified as O. crassidens are in fact representatives of the Chadian O. djourabensis. Moreover, additional material from Ethiopia and Kenya shows a close relationship with the latter species too. The presence of specimens of O. djourabensis in Chad and in Kenya during the Plio-Pleistocene implies that this taxon is the oldest-known species of aardvark to have experienced a continental dispersal. It also shows that Tubulidentates were able to cross Africa from east-west during Plio-Pleistocene times, despite the presence of the Rift Valley. It is however not possible to infer the centre of origin of O. djourabensis. Finally, this study suggests that two species of aardvark might have co-existed in Kenya during the early Pleistocene.doi:10.1002/mmng.200800003

Published
2008
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36. Continuous table tennis is associated with processing in frontal brain areas: an EEG approach

Author

Anton Visser, D. Büchel, T. Lehmann, and J. Baumeister

Subjects
Young Adult, Cognition, General Neuroscience, Tennis, Brain, Humans, Electroencephalography, Frontal Lobe
Abstract

Coordinative challenging exercises in changing environments referred to as open-skill exercises seem to be beneficial on cognitive function. Although electroencephalographic research allows to investigate changes in cortical processing during movement, information about cortical dynamics during open-skill exercise is lacking. Therefore, the present study examines frontal brain activation during table tennis as an open-skill exercise compared to cycling exercise and a cognitive task. 21 healthy young adults conducted three blocks of table tennis, cycling and n-back task. Throughout the experiment, cortical activity was measured using 64-channel EEG system connected to a wireless amplifier. Cortical activity was analyzed calculating theta power (4–7.5 Hz) in frontocentral clusters revealed from independent component analysis. Repeated measures ANOVA was used to identify within subject differences between conditions (table tennis, cycling, n-back; p p ηp2 = 0.35) and frontocentral (p ηp2 = 0.39) brain areas. Post-hoc tests revealed increased theta power in table tennis compared to cycling in frontal brain areas (p d = 1.42). In frontocentral brain areas, theta power was significant higher in table tennis compared to cycling (p d = 1.03) and table tennis compared to the cognitive task (p d = 1.06). Increases in theta power during continuous table tennis may reflect the increased demands in perception and processing of environmental stimuli during open-skill exercise. This study provides important insights that support the beneficial effect of open-skill exercise on brain function and suggest that using open-skill exercise may serve as an intervention to induce activation of the frontal cortex.

Published
2021

40. Erratum to: The effectiveness of the paclitaxel-coated Luminor® balloon catheter versus an uncoated balloon catheter in superficial femoral and popliteal arteries in preventing vessel restenosis or reocclusion: study protocol for a randomized controlled trial

Author

U. Teichgräber, R. Aschenbach, D. Scheinert, T. Zeller, K. Brechtel, M. Thieme, E. Blessing, M. Treitl, M. Lichtenberg, P. von Flotow, B. Vogel, M. Werk, V. Riambau, A. Wienke, T. Lehmann, and S. Sixt

Subjects
Medicine (General), R5-920
Published
2017
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41. Phenotyping in the era of genomics:MaTrics– a digital character matrix to document mammalian phenotypic traits coded numerically

Author

G. Unterhitzenberger, M. Rudolf, P. Wehner, Michael Hiller, C. Stefen, Peter Giere, F. Wagner, C. Schiffmann, T. Lehmann, I. Ruf, Heiko Stuckas, L. Vogt, M. Asztalos, P. Grobe, N. Thier, B. Peters, R. Hofmann, M. Jaehde, Sylvia Ortmann, and U. Laechele

Subjects
Comparative genomics, Ecology (disciplines), Trait, Mammalogy, Genomics, Computational biology, Phenotypic trait, Information repository, Biology, Genome
Abstract

A new and uniquely structured matrix of mammalian phenotypes,MaTrics(MammalianTraits for Comparative Genomics) is presented in a digital form. By focussing on mammalian species for which genome assemblies are available,MaTricsprovides an interface between mammalogy and comparative genomics.MaTricswas developed as part of a project to link phenotypic differences between mammals to differences in their genomes usingForward Genomics.Apart from genomes this approach requires information on homologous phenotypes that are numerically encoded (presence-absence; multistate character coding*) in a matrix.MaTricsprovides these data, links them to at least one reference (e.g., literature, photographs, histological sections, CT-scans, or museum specimens) and makes them available in a machine actionable NEXUS-format. By making the data computer readable,MatTricsopens a new way for digitizing collections. Currently,MaTricscovers 147 mammalian species and includes 207 characters referring to structure, morphology, physiology, ecology and ethology. Researching these traits revealed substantial knowledge gaps, highlighting the need for substantial phenotyping efforts in the genomic era. Using the trait information documented inMaTrics, previous Forward Genomics screens identified changes in genes that are associated with various phenotypes, ranging from fully-aquatic lifestyle to dietary specializations. These results motivate the continuous expansion of phenotype information, both by filling research gaps or by adding additional taxa and traits.MaTricsis digitally available online within the data repository Morph·D·Base (www.morphdbase.de).

Published
2021
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42. Deep underground neutrino experiment (DUNE) near detector conceptual design report

Author

Abud, A.A. Abi, B. Acciarri, R. Acero, M.A. Adamov, G. Adams, D. Adinolfi, M. Aduszkiewicz, A. Ahmad, Z. Ahmed, J. Alion, T. Monsalve, S.A. Alrashed, M. Alt, C. Alton, A. Amedo, P. Anderson, J. Andreopoulos, C. Andrews, M.P. Andrianala, F. Andringa, S. Anfimov, N. Ankowski, A. Antonova, M. Antusch, S. Aranda-Fernandez, A. Ariga, A. Arnold, L.O. Arroyave, M.A. Asaadi, J. Aurisano, A. Aushev, V. Autiero, D. Ayala-Torres, M. Azfar, F. Back, A. Back, H. Back, J.J. Backhouse, C. Baesso, P. Bagaturia, I. Bagby, L. Balasubramanian, S. Baldi, P. Baller, B. Bambah, B. Barao, F. Barenboim, G. Barker, G.J. Barkhouse, W. Barnes, C. Barr, G. Monarca, J.B. Barros, N. Barrow, J.L. Basharina-Freshville, A. Bashyal, A. Basque, V. Belchior, E. Battat, J.B.R. Battisti, F. Bay, F. Alba, J.L.B. Beacom, J.F. Bechetoille, E. Behera, B. Bellantoni, L. Bellettini, G. Bellini, V. Beltramello, O. Belver, D. Benekos, N. Neves, F.B. Berkman, S. Bernardini, P. Berner, R.M. Berns, H. Bertolucci, S. Betancourt, M. Rodríguez, A.B. Bhattacharjee, M. Bhuller, S. Bhuyan, B. Biagi, S. Bian, J. Biassoni, M. Biery, K. Bilki, B. Bishai, M. Bitadze, A. Blake, A. Blaszczyk, F.D.M. Blazey, G.C. Blucher, E. Boissevain, J. Bolognesi, S. Bolton, T. Bomben, L. Bonesini, M. Bongrand, M. Bonini, F. Booth, A. Booth, C. Bordoni, S. Borkum, A. Boschi, T. Bostan, N. Bour, P. Bourgeois, C. Boyd, S.B. Boyden, D. Bracinik, J. Braga, D. Brailsford, D. Brandt, A. Bremer, J. Brew, C. Brianne, E. Brice, S.J. Brizzolari, C. Bromberg, C. Brooijmans, G. Brooke, J. Bross, A. Brunetti, G. Brunetti, M. Buchanan, N. Budd, H. Cagnoli, I. Caiulo, D. Calafiura, P. Calcutt, J. Calin, M. Calvez, S. Calvo, E. Caminata, A. Campanelli, M. Cankocak, K. Caratelli, D. Carini, G. Carlus, B. Carniti, P. Terrazas, I.C. Carranza, H. Carroll, T. Castaño Forero, J.F. Castillo, A. Castromonte, C. Catano-Mur, E. Cattadori, C. Cavalier, F. Cavanna, F. Centro, S. Cerati, G. Cervelli, A. Villanueva, A.C. Chalifour, M. Chappell, A. Chardonnet, E. Charitonidis, N. Chatterjee, A. Chattopadhyay, S. Chen, H. Chen, M. Chen, Y. Chen, Z. Cherdack, D. Chi, C. Childress, S. Chiriacescu, A. Chisnall, G. Cho, K. Choate, S. Chokheli, D. Choubey, S. Christensen, A. Christian, D. Christodoulou, G. Chukanov, A. Church, E. Cicero, V. Clarke, P. Coan, T.E. Cocco, A.G. Coelho, J.A.B. Conley, E. Conley, R. Conrad, J.M. Convery, M. Copello, S. Corwin, L. Cremaldi, L. Cremonesi, L. Crespo-Anadón, J.I. Cristaldo, E. Cross, R. Cudd, A. Cuesta, C. Cui, Y. Cussans, D. Dabrowski, M. Dalager, O. Da Motta, H. Da Silva Peres, L. David, C. David, Q. Davies, G.S. Davini, S. Dawson, J. De, K. De Almeida, R.M. Debbins, P. De Bonis, I. Decowski, M.P. De Gouvêa, A. De Holanda, P.C. De Icaza Astiz, I.L. Deisting, A. De Jong, P. Delbart, A. Delepine, D. Delgado, M. Dell’Acqua, A. De Lurgio, P. De Mello Neto, J.R.T. De Muth, D.M. Dennis, S. Densham, C. Deptuch, G.W. De Roeck, A. De Romeri, V. De Souza, G. Dharmapalan, R. Diaz, F. Díaz, J.S. Di Domizio, S. Di Giulio, L. Ding, P. Di Noto, L. Distefano, C. Diurba, R. Diwan, M. Djurcic, Z. Dokania, N. Dolan, S. Dolinski, M.J. Domine, L. Douglas, D. Douillet, D. Drake, G. Drielsma, F. Duchesneau, D. Duffy, K. Dunne, P. Durkin, T. Duyang, H. Dvornikov, O. Dwyer, D.A. Dyshkant, A.S. Eads, M. Earle, A. Edmunds, D. Eisch, J. Emberger, L. Emery, S. Ereditato, A. Escobar, C.O. Eurin, G. Evans, J.J. Ewart, E. Ezeribe, A.C. Fahey, K. Falcone, A. Farnese, C. Farzan, Y. Felix, J. Carneiro Da Silva, M.F. Fernandez-Martinez, E. Fernandez Menendez, P. Ferraro, F. Fields, L. Filthaut, F. Fiorentini, A. Fitzpatrick, R.S. Flanagan, W. Fleming, B. Flight, R. Forero, D.V. Fowler, J. Fox, W. Franc, J. Francis, K. Franco, D. Freeman, J. Freestone, J. Fried, J. Friedland, A. Fuess, S. Furic, I. Furmanski, A.P. Gabrielli, A. Gago, A. Gallagher, H. Gallas, A. Gallego-Ros, A. Gallice, N. Galymov, V. Gamberini, E. Gamble, T. Gandhi, R. Gandrajula, R. Gao, F. Gao, S. Garcia-Gamez, D. García-Peris, M.Á. Gardiner, S. Gastler, D. Ge, G. Gelli, B. Gendotti, A. Gent, S. Ghorbani-Moghaddam, Z. Gibin, D. Gil-Botella, I. Gilligan, S. Girerd, C. Giri, A.K. Gnani, D. Gogota, O. Gold, M. Gollapinni, S. Gollwitzer, K. Gomes, R.A. Gomez Bermeo, L.V. Gomez Fajardo, L.S. Gonnella, F. Gonzalez-Cuevas, J.A. Gonzalez-Diaz, D. Gonzalez-Lopez, M. Goodman, M.C. Goodwin, O. Goswami, S. Gotti, C. Goudzovski, E. Grace, C. Graham, M. Gran, R. Granados, E. Granger, P. Grant, A. Grant, C. Gratieri, D. Green, P. Greenler, L. Greer, J. Griffith, W.C. Groh, M. Grudzinski, J. Grzelak, K. Gu, W. Guarino, V. Guenette, R. Guerard, E. Guerzoni, M. Guglielmi, A. Guo, B. Guthikonda, K.K. Gutierrez, R. Guzowski, P. Guzzo, M.M. Gwon, S. Habig, A. Hadavand, H. Haenni, R. Hahn, A. Haiston, J. Hamacher-Baumann, P. Hamernik, T. Hamilton, P. Han, J. Harris, D.A. Hartnell, J. Harton, J. Hasegawa, T. Hasnip, C. Hatcher, R. Hatfield, K.W. Hatzikoutelis, A. Hayes, C. Hazen, E. Heavey, A. Heeger, K.M. Heise, J. Hennessy, K. Henry, S. Hernandez Morquecho, M.A. Herner, K. Hertel, L. Hewes, J. Higuera, A. Hill, T. Hillier, S.J. Himmel, A. Hoff, J. Hohl, C. Holin, A. Hoppe, E. Horton-Smith, G.A. Hostert, M. Hourlier, A. Howard, B. Howell, R. Huang, J. Huang, J. Hugon, J. Iles, G. Ilic, N. Iliescu, A.M. Illingworth, R. Ingratta, G. Ioannisian, A. Isenhower, L. Itay, R. Izmaylov, A. Jackson, S. Jain, V. James, E. Jargowsky, B. Jediny, F. Jena, D. Jeong, Y.S. Jesús-Valls, C. Ji, X. Jiang, L. Jiménez, S. Jipa, A. Johnson, R. Johnston, N. Jones, B. Jones, S.B. Judah, M. Jung, C.K. Junk, T. Jwa, Y. Kabirnezhad, M. Kaboth, A. Kadenko, I. Kakorin, I. Kamiya, F. Kaneshige, N. Karagiorgi, G. Karaman, G. Karcher, A. Karolak, M. Karyotakis, Y. Kasai, S. Kasetti, S.P. Kashur, L. Kazaryan, N. Kearns, E. Keener, P. Kelly, K.J. Kemp, E. Kemularia, O. Ketchum, W. Kettell, S.H. Khabibullin, M. Khotjantsev, A. Khvedelidze, A. Kim, D. King, B. Kirby, B. Kirby, M. Klein, J. Koehler, K. Koerner, L.W. Kohn, S. Koller, P.P. Kolupaeva, L. Kordosky, M. Kosc, T. Kose, U. Kostelecký, V.A. Kothekar, K. Krennrich, F. Kreslo, I. Kudenko, Y. Kudryavtsev, V.A. Kulagin, S. Kumar, J. Kumar, P. Kumar, R. Kunze, P. Kurita, N. Kuruppu, C. Kus, V. Kutter, T. Lambert, A. Land, B. Lande, K. Lane, C.E. Lang, K. Langford, T. Larkin, J. Lasorak, P. Last, D. Lastoria, C. Laundrie, A. Laurenti, G. Lawrence, A. Lazanu, I. Lazur, R. Le, T. Leardini, S. Learned, J. Lebrun, P. Lecompte, T. Lehmann Miotto, G. Lehnert, R. Leigui De Oliveira, M.A. Leitner, M. Li, L. Li, S.W. Li, T. Li, Y. Liao, H. Lin, C.S. Lin, Q. Lin, S. Lister, A. Littlejohn, B.R. Liu, J. Lockwitz, S. Loew, T. Lokajicek, M. Lomidze, I. Long, K. Loo, K. Lorca, D. Lord, T. Losecco, J.M. Louis, W.C. Lu, X.-G. Luk, K.B. Luo, X. Lurkin, N. Lux, T. Luzio, V.P. Macfarlane, D. Machado, A.A. Machado, P. Macias, C.T. Macier, J.R. Maddalena, A. Madera, A. Madigan, P. Magill, S. Mahn, K. Maio, A. Major, A. Maloney, J.A. Mandrioli, G. Mandujano, R.C. Maneira, J. Manenti, L. Manly, S. Mann, A. Manolopoulos, K. Manrique Plata, M. Manyam, V.N. Manzanillas, L. Marchan, M. Marchionni, A. Marciano, W. Marfatia, D. Mariani, C. Maricic, J. Marie, R. Marinho, F. Marino, A.D. Marsden, D. Marshak, M. Marshall, C.M. Marshall, J. Marteau, J. Martin-Albo, J. Martinez, N. Martinez Caicedo, D.A. Martynenko, S. Mason, K. Mastbaum, A. Masud, M. Matsuno, S. Matthews, J. Mauger, C. Mauri, N. Mavrokoridis, K. Mawby, I. Mazza, R. Mazzacane, A. Mazzucato, E. McAskill, T. McCluskey, E. McConkey, N. McFarland, K.S. McGrew, C. McNab, A. Mefodiev, A. Mehta, P. Melas, P. Mena, O. Menary, S. Mendez, H. Méndez, D.P. Menegolli, A. Meng, G. Messier, M.D. Metcalf, W. Mettler, T. Mewes, M. Meyer, H. Miao, T. Michna, G. Miedema, T. Migenda, J. Mikola, V. Milincic, R. Miller, W. Mills, J. Milne, C. Mineev, O. Miranda, O.G. Miryala, S. Mishra, C.S. Mishra, S.R. Mislivec, A. Mladenov, D. Mocioiu, I. Moffat, K. Moggi, N. Mohanta, R. Mohayai, T.A. Mokhov, N. Molina, J. Molina Bueno, L. Montanari, A. Montanari, C. Montanari, D. Montagna, E. Montano Zetina, L.M. Moon, J. Mooney, M. Moor, A.F. Moreno, D. Morris, C. Mossey, C. Motuk, E. Moura, C.A. Mousseau, J. Mu, W. Mualem, L. Mueller, J. Muether, M. Mufson, S. Muheim, F. Muir, A. Mulhearn, M. Munford, D. Muramatsu, H. Murphy, S. Musser, J. Nachtman, J. Nagu, S. Nalbandyan, M. Nandakumar, R. Naples, D. Narita, S. Navas-Nicolás, D. Navrer-Agasson, A. Nayak, N. Nebot-Guinot, M. Negishi, K. Nelson, J.K. Nesbit, J. Nessi, M. Newbold, D. Newcomer, M. Newhart, D. Newton, H. Niccolo, M. Nichol, R. Nicolas-Arnaldos, F. Nicoletta, M. Niner, E. Nishimura, K. Norman, A. Norrick, A. Northrop, R. Novella, P. Nowak, J.A. Oberling, M. Ochoa-Ricoux, J.P. Olivares Del Campo, A. Olivier, A. Olshevskiy, A. Onel, Y. Onishchuk, Y. Ott, J. Pagani, L. Pakvasa, S. Palacio, G. Palamara, O. Palestini, S. Paley, J.M. Pallavicini, M. Palomares, C. Palomino-Gallo, J.L. Pantic, E. Paolone, V. Papadimitriou, V. Papaleo, R. Papanestis, A. Paramesvaran, S. Parke, S. Parsa, Z. Parvu, M. Pascoli, S. Pasqualini, L. Pasternak, J. Pater, J. Patrick, C. Patrizii, L. Patterson, R.B. Patton, S.J. Patzak, T. Paudel, A. Paulos, B. Paulucci, L. Pavlovic, Z. Pawloski, G. Payne, D. Pec, V. Peeters, S.J.M. Pennacchio, E. Penzo, A. Peres, O.L.G. Perry, J. Pershey, D. Pessina, G. Petrillo, G. Petta, C. Petti, R. Piastra, F. Pickering, L. Pietropaolo, F. Plunkett, R. Poling, R. Pons, X. Poonthottathil, N. Poppi, F. Pordes, S. Porter, J. Potekhin, M. Potenza, R. Potukuchi, B.V.K.S. Pozimski, J. Pozzato, M. Prakash, S. Prakash, T. Prince, S. Pugnere, D. Qian, X. Queiroga Bazetto, M.C. Raaf, J.L. Radeka, V. Rademacker, J. Radics, B. Rafique, A. Raguzin, E. Rai, M. Rajaoalisoa, M. Rakhno, I. Rakotonandrasana, A. Rakotondravohitra, L. Ramachers, Y.A. Rameika, R. Ramirez Delgado, M.A. Ramson, B. Rappoldi, A. Raselli, G. Ratoff, P. Raut, S. Razakamiandra, R.F. Real, J.S. Rebel, B. Reggiani-Guzzo, M. Rehak, T. Reichenbacher, J. Reitzner, S.D. Rejeb Sfar, H. Renshaw, A. Rescia, S. Resnati, F. Reynolds, A. Riccio, C. Riccobene, G. Rice, L.C.J. Ricol, J. Rigamonti, A. Rigaut, Y. Rivera, D. Rochester, L. Roda, M. Rodrigues, P. Rodriguez Alonso, M.J. Rodriguez Bonilla, E. Rodriguez Rondon, J. Rosauro-Alcaraz, S. Rosenberg, M. Rosier, P. Roskovec, B. Rossella, M. Rout, J. Roy, P. Roy, S. Rubbia, A. Rubbia, C. Rubio, F.C. Russell, B. Ruterbories, D. Saakyan, R. Sacerdoti, S. Safford, T. Sahay, R. Sahu, N. Sala, P. Samios, N. Samoylov, O. Sanchez, M.C. Sanders, D.A. Sankey, D. Santana, S. Santos-Maldonado, M. Saoulidou, N. Sapienza, P. Sarasty, C. Sarcevic, I. Savage, G. Savinov, V. Scaramelli, A. Scarff, A. Scarpelli, A. Schaffer, T. Schellman, H. Schlabach, P. Schmitz, D. Scholberg, K. Schukraft, A. Segreto, E. Sensenig, J. Seong, I. Sergi, A. Sgalaberna, D. Shaevitz, M.H. Shafaq, S. Shamma, M. Sharankova, R. Sharma, H.R. Sharma, R. Shaw, T. Shepherd-Themistocleous, C. Shin, S. Shooltz, D. Shrock, R. Simard, L. Simon, F. Simos, N. Sinclair, J. Sinev, G. Singh, J. Singh, J. Singh, V. Sipos, R. Sippach, F.W. Sirri, G. Sitraka, A. Siyeon, K. Skarpaas, K. Smith, A. Smith, E. Smith, P. Smolik, J. Smy, M. Snider, E.L. Snopok, P. Soares Nunes, M. Sobel, H. Soderberg, M. Solano Salinas, C.J. Söldner-Rembold, S. Soleti, S. Solomey, N. Solovov, V. Sondheim, W.E. Sorel, M. Soto-Oton, J. Sousa, A. Soustruznik, K. Spagliardi, F. Spanu, M. Spitz, J. Spooner, N.J.C. Spurgeon, K. Staley, R. Stancari, M. Stanco, L. Stanley, R. Stein, R. Steiner, H.M. Stewart, J. Stillwell, B. Stock, J. Stocker, F. Stokes, T. Strait, M. Strauss, T. Striganov, S. Stuart, A. Suarez, J.G. Sullivan, H. Summers, D. Surdo, A. Susic, V. Suter, L. Sutera, C.M. Svoboda, R. Szczerbinska, B. Szelc, A.M. Talaga, R. Tanaka, H.A. Oregui, B.T. Tapper, A. Tariq, S. Tatar, E. Tayloe, R. Teklu, A.M. Tenti, M. Terao, K. Ternes, C.A. Terranova, F. Testera, G. Thea, A. Thompson, J.L. Thorn, C. Timm, S.C. Todd, J. Tonazzo, A. Torbunov, D. Torti, M. Tortola, M. Tortorici, F. Totani, D. Toups, M. Touramanis, C. Tosi, N. Travaglini, R. Trevor, J. Trilov, S. Trzaska, W.H. Tsai, Y.T. Tsamalaidze, Z. Tsang, K.V. Tsverava, N. Tufanli, S. Tull, C. Tyley, E. Tzanov, M. Uchida, M.A. Urheim, J. Usher, T. Uzunyan, S. Vagins, M.R. Vahle, P. Valdiviesso, G.A. Valencia, E. Valerio, P. Vallari, Z. Valle, J.W.F. Vallecorsa, S. Van Berg, R. Van De Water, R.G. Varanini, F. Vargas, D. Varner, G. Vasel, J. Vasina, S. Vasseur, G. Vaughan, N. Vaziri, K. Ventura, S. Verdugo, A. Vergani, S. Vermeulen, M.A. Verzocchi, M. Vicenzi, M. Vieira De Souza, H. Vignoli, C. Vilela, C. Viren, B. Vrba, T. Wachala, T. Waldron, A.V. Wallbank, M. Wang, H. Wang, J. Wang, L. Wang, M.H.L.S. Wang, Y. Wang, Y. Warburton, K. Warner, D. Wascko, M. Waters, D. Watson, A. Weatherly, P. Weber, A. Weber, M. Wei, H. Weinstein, A. Wenman, D. Wetstein, M. White, A. Whitehead, L.H. Whittington, D. Wilking, M.J. Wilkinson, C. Williams, Z. Wilson, F. Wilson, R.J. Wolcott, J. Wongjirad, T. Wood, A. Wood, K. Worcester, E. Worcester, M. Wret, C. Wu, W. Wu, W. Xiao, Y. Yandel, E. Yang, G. Yang, K. Yang, S. Yang, T. Yankelevich, A. Yershov, N. Yonehara, K. Young, T. Yu, B. Yu, H. Yu, J. Yuan, W. Zaki, R. Zalesak, J. Zambelli, L. Zamorano, B. Zani, A. Zazueta, L. Zeit, G. Zeller, G.P. Zennamo, J. Zeug, K. Zhang, C. Zhao, M. Zhivun, E. Zhu, G. Zilberman, P. Zimmerman, E.D. Zito, M. Zucchelli, S. Zuklin, J. Zutshi, V. Zwaska, R. DUNE Collaboration

Subjects
Physics::Instrumentation and Detectors, High Energy Physics::Experiment
Abstract

The Deep Underground Neutrino Experiment (DUNE) is an international, world-class experiment aimed at exploring fundamental questions about the universe that are at the forefront of astrophysics and particle physics research. DUNE will study questions pertaining to the preponderance of matter over antimatter in the early universe, the dynamics of supernovae, the subtleties of neutrino interaction physics, and a number of beyond the Standard Model topics accessible in a powerful neutrino beam. A critical component of the DUNE physics program involves the study of changes in a powerful beam of neutrinos, i.e., neutrino oscillations, as the neutrinos propagate a long distance. The experiment consists of a near detector, sited close to the source of the beam, and a far detector, sited along the beam at a large distance. This document, the DUNE Near Detector Conceptual Design Report (CDR), describes the design of the DUNE near detector and the science program that drives the design and technology choices. The goals and requirements underlying the design, along with projected performance are given. It serves as a starting point for a more detailed design that will be described in future documents. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Published
2021

44. The magnetic field vector of the Sun-as-a-star – II. Evolution of the large-scale vector field through activity cycle 24

Author

Aline A. Vidotto, Alexei A. Pevtsov, Moira Jardine, L. T. Lehmann, Science & Technology Facilities Council, and University of St Andrews. School of Physics and Astronomy

Subjects
Scale (ratio), Library science, 01 natural sciences, Surface magnetism, Physics::Plasma Physics, analytical [Methods], 0103 physical sciences, QB Astronomy, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Magnetic topology, QC, QB, Physics, Solar observatory, 010308 nuclear & particles physics, DAS, Astronomy and Astrophysics, QC Physics, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Magnetic fields, Physics::Space Physics, Activity cycle, Vector field, Astrophysics::Earth and Planetary Astrophysics, Partial support
Abstract

In the present work, we investigate how the large-scale magnetic field of the Sun, in its three vector components, has evolved during most of cycle 24, from 2010 Jan to 2018 Apr. To filter out the small-scale field of the Sun, present in high-resolution synoptic maps, we use a spherical harmonic decomposition method, which decomposes the solar field in multipoles with different l degrees. By summing together the low-l multipoles, we reconstruct the large-scale field at a resolution similar to observed stellar magnetic fields, which allows the direct comparison between solar and stellar magnetic maps. During cycle 24, the `Sun-as-a-star' magnetic field shows a polarity reversal in the radial and meridional components, but not in the azimuthal component. The large-scale solar field remains mainly poloidal with > 70% of its energy contained in the poloidal component. During its evolution, the large-scale field is more axisymmetric and more poloidal when near minima in sunspot numbers, and with a larger intensity near maximum. There is a correlation between toroidal energy and sunspot number, which indicates that spot fields are major contributors to the toroidal large-scale energy of the Sun. The solar large-scale magnetic properties fit smoothly with observational trends of stellar magnetism reported in See et al. The toroidal (Etor) and poloidal (Epol) energies are related as Etor ~Epol^{1.38 \pm 0.04}. Similar to the stellar sample, the large-scale field of the Sun shows a lack of toroidal non-axisymmetric field., Comment: 11 pages, 9 figures, 3 tables. Accepted to MNRAS

Published
2018
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45. Influence of different nucleation layers on the initial grain structure of multicrystalline silicon ingots

Author

C. Kranert, I. Kupka, T. Lehmann, Matthias Trempa, Jochen Friedrich, Christian Reimann, and Publica

Subjects
010302 applied physics, Materials science, Nucleation, 02 engineering and technology, Surface finish, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Grain size, Inorganic Chemistry, Crystallography, 0103 physical sciences, Materials Chemistry, Surface roughness, Grain boundary, Wetting, Ingot, Composite material, 0210 nano-technology, Grain boundary strengthening
Abstract

The grain structure of high-performance (HP) multicrystalline silicon (mc-Si) is characterized by a small initial grain size with randomly oriented grains and a high length fraction of random grain boundaries. However, the remaining unmelted feedstock at the ingot bottom used as seeding layer for achieving the HP mc-Si properties in the standard crystallization procedure causes yield loss. To overcome this disadvantage, the influence of wetting angle, and surface roughness of non-Si nucleation layers at the crucible bottom on the grain structure properties of mc-Si ingots with a weight of 14.5 kg was investigated and compared to classical HP mc-Si. For that purpose, SiC and SiO 2 nucleation layers realized by spraying and embedding of particles with different sizes resulting in different surface morphologies and wetting angles were studied. Nucleation on rough layers of both materials with a root mean square roughness value greater than 100 µm yielded an initially fine grain structure comparable to HP mc-Si. This did not necessarily result in a random orientation distribution and high length fraction of random grain boundaries. Nucleation on SiC layers caused random grain boundary length fractions between 20 and 30% and non-uniform grain distributions. But, nucleation on SiO 2 layers yielded increased random grain boundary length fractions between 50 and 70% and homogenous grain distributions, both values are similar to HP mc-Si. These differences are discussed in terms of the thermal conductivity of the different nucleation layers.

Published
2017
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46. Ethnicity, Health Literacy, and Outcomes in Heart Failure

Author

Stephanie M.G. Williams, Joseph T. Lehmann, Ali Kirresh, and Mahmood Ahmad

Subjects
Gerontology, business.industry, Ethnic group, Health literacy, 030204 cardiovascular system & hematology, medicine.disease, Confidence interval, 03 medical and health sciences, 0302 clinical medicine, Increased risk, Relative risk, Heart failure, Medicine, 030212 general & internal medicine, Cardiology and Cardiovascular Medicine, business
Abstract

We were interested to read the study by Fabbri et al. ([1][1]), a meta-analysis which investigated the association between health literacy and outcomes in heart failure patients. The study demonstrated an increased risk of death (risk ratio [RR]: 1.41; 95% confidence interval [CI]: 1.06 to 1.88)

Published
2020
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47. Measuring stellar magnetic helicity density

Author

Duncan H. Mackay, Moira Jardine, L. T. Lehmann, Aline A. Vidotto, Colin P. Folsom, Victor See, Sandra V. Jeffers, Stephen C. Marsden, Rim Fares, Julien Morin, K. Lund, J.-F. Donati, Pascal Petit, University of St Andrews [Scotland], University of Exeter, Trinity College Dublin, Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), United Arab Emirates University, Institut für Astrophysik [Göttingen], Georg-August-University [Göttingen], University of Southern Queensland (USQ), Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Science & Technology Facilities Council, European Research Council, University of St Andrews. School of Physics and Astronomy, and University of St Andrews. Applied Mathematics

Subjects
Stellar mass, FOS: Physical sciences, Astrophysics, 01 natural sciences, Power law, methods: analytical, Magnetic helicity, analytical [Methods], 0103 physical sciences, QB Astronomy, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Sun: magnetic fields, Solar and Stellar Astrophysics (astro-ph.SR), QB, Physics, Magnetic energy, 010308 nuclear & particles physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], stars: magnetic field, DAS, Astronomy and Astrophysics, Helicity, Magnetic field, Solar cycle, magnetic field [Stars], Stars, magnetic fields [Sun], Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics
Abstract

Helicity is a fundamental property of a magnetic field but to date it has only been possible to observe its evolution in one star - the Sun. In this paper we provide a simple technique for mapping the large-scale helicity density across the surface of any star using only observable quantities: the poloidal and toroidal magnetic field components (which can be determined from Zeeman-Doppler imaging) and the stellar radius. We use a sample of 51 stars across a mass range of 0.1-1.34 M$_\odot$ to show how the helicity density relates to stellar mass, Rossby number, magnetic energy and age. We find that the large-scale helicity density increases with decreasing Rossby number $R_o$, peaking at $R_o \simeq 0.1$, with a saturation or decrease below that. For both fully- and partially-convective stars we find that the mean absolute helicity density scales with the mean squared toroidal magnetic flux density according to the power law: $|\langle{h\,}\rangle|$ $\propto$ $\langle{\rm{B_{tor}}^2_{}\,\rangle}^{0.86\,\pm\,0.04}$. The scatter in this relation is consistent with the variation across a solar cycle, which we compute using simulations and observations across solar cycles 23 and 24 respectively. We find a significant decrease in helicity density with age., 11 pages, 7 figures

Published
2020
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48. How much do underestimated field strengths from Zeeman-Doppler imaging affect spin-down torque estimates?

Author

Victor See, Sean P. Matt, L. T. Lehmann, and Adam J. Finley

Subjects
Physics, Angular momentum, Field (physics), 010308 nuclear & particles physics, Flux, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Zeeman–Doppler imaging, 01 natural sciences, Magnetic field, Stars, Dipole, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Spin-½
Abstract

Numerous attempts to estimate the rate at which low-mass stars lose angular momentum over their lifetimes exist in the literature. One approach is to use magnetic maps derived from Zeeman-Doppler imaging (ZDI) in conjunction with so-called "braking laws". The use of ZDI maps has advantages over other methods because it allows information about the magnetic field geometry to be incorporated into the estimate. However, ZDI is known to underestimate photospheric field strengths due to flux cancellation effects. Recently, Lehmann et al. (2018) conducted synthetic ZDI reconstructions on a set of flux transport simulations to help quantify the amount by which ZDI underestimates the field strengths of relatively slowly rotating and weak activity solar-like stars. In this paper, we evaluate how underestimated angular momentum-loss rate estimates based on ZDI maps may be. We find that they are relatively accurate for stars with strong magnetic fields but may be underestimated by a factor of up to $\sim$10 for stars with weak magnetic fields. Additionally, we re-evaluate our previous work that used ZDI maps to study the relative contributions of different magnetic field modes to angular momentum-loss. We previously found that the dipole component dominates spin-down for most low-mass stars. This conclusion still holds true even in light of the work of Lehmann et al. (2018)., Comment: 8 pages, 3 figures, 1 table, accepted for publication by ApJ

Published
2020
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