cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Competing Formate- and Carbon Dioxide-Utilizing Prokaryotes in an Anoxic Methane-Emitting Fen Soil
Creators: name: Hunger, Sindy
name: Schmidt, Oliver
name: Hilgarth, Maik
name: Horn, Marcus A.
name: Kolb, Steffen
name: Conrad, Ralf
name: Drake, Harold L.
Publisher: name: Washington, DC [u.a.] : American Soc. for Microbiology
Year: 2011
Subjects: subject: Anaerobiosis
subject: Biodiversity
subject: Carbon Dioxide
subject: Carbon Isotopes
subject: Cluster Analysis
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: Methanogenesis in wetlands is dependent on intermediary substrates derived from the degradation of biopolymers. Formate is one such substrate and is stimulatory to methanogenesis and acetogenesis in anoxic microcosms of soil from the fen Schlöppnerbrunnen. Formate dissimilation also yields CO2 as a potential secondary substrate. The objective of this study was to resolve potential differences between anaerobic formateand CO2-utilizing prokaryotes of this fen by stable isotope probing. Anoxic soil microcosms were pulsed daily with low concentrations of [13C]formate or 13CO2 (i.e., [13C]bicarbonate). Taxa were evaluated by assessment of 16S rRNA genes, mcrA (encoding the alpha-subunit of methyl-coenzyme M reductase), and fhs (encoding formyltetrahydrofolate synthetase). Methanogens, acetogens, and formate-hydrogen lyase-containing taxa appeared to compete for formate. Genes affiliated with Methanocellaceae, Methanobacteriaceae, Acetobacteraceae, and Rhodospirillaceae were 13C enriched (i.e., labeled) in [13C]formate treatments, whereas genes affiliated with Methanosarcinaceae, Conexibacteraceae, and Solirubrobacteraceae were labeled in 13CO2 treatments. [13C]acetate was enriched in [13C]formate treatments, but labeling of known acetogenic taxa was not detected. However, several phylotypes were affiliated with acetogen-containing taxa (e.g., Sporomusa). Methanosaetaceae-affiliated methanogens appeared to participate in the consumption of acetate. Twelve and 58 family-level archaeal and bacterial 16S rRNA phylotypes, respectively, were detected, approximately half of which had no isolated representatives. Crenarchaeota constituted half of the detected archaeal 16S rRNA phylotypes. The results highlight the unresolved microbial diversity of the fen Schlöppnerbrunnen, suggest that differing taxa competed for the same substrate, and indicate that Methanocellaceae, Methanobacteriaceae, Methanosarcinaceae, and Methanosaetaceae were linked to the production of methane, but they do not clearly resolve the taxa responsible for the apparent conversion of formate to acetate. © 2011, American Society for Microbiology.
Complex Plasmas as a Model for the Quark-Gluon-Plasma Liquid
Creators: name: Thoma, Markus H.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The quark-gluon plasma, possibly created in ultrarelativistic heavy-ion collisions, is a strongly interacting many-body parton system. By comparison with strongly coupled electromagnetic plasmas (classical and non-relativistic) it is concluded that the quark-gluon plasma could be in the liquid phase. As an example for a strongly coupled plasma, complex plasmas, which show liquid and even solid phases, are discussed briefly. Furthermore, methods based on correlation functions for confirming and investigating the quark-gluon-plasma liquid are presented. Finally, consequences of the strong coupling, in particular a cross section enhancement in accordance with experimental observations at RHIC, are discussed.
description: 8 pages, 4 figures, contribution to the Quark Matter 2005 proceedings
PRESERVATION AND MAINTENANCE OF VIRUS-FREE CLONAL CITRUS GERMPLASM AT THE NATIONAL CLONAL GERMPLASM REPOSITORY FOR CITRUS, RIVERSIDE, CALIFORNIA
Creators: name: Williams, T.E.
name: Williams, T.E.
Publisher: name: Unknown
Year: 1990
Subjects: Crop Production/Industries
Research and Development/Tech Change/Emerging Technologies

description: The United States Department of Agriculture's National Clonal Germplasm Repository for Citrus is currently establishing a virus-free clonal germplasm collection of 830 accessions of citrus and related Aurantioideae genera at its Riverside, California, facility with the objective of reducing genetic vulnerability of the crop and providing a source of virus-free clonal germplasm to researchers worldwide. Emphasis of the collection centers on the acquisition and ex-situ preservation, maintenance, evaluation and distribution of genera, species and cultivars representing the widest possible genetic diversity with the citrus subfamily. The Repository plan includes a comprehensive program of genetic characterization, pathogen detection and elimination, pest management, propagation in a controlled and protected environment, and documentation. All accessions are evaluated for trueness-to-type using leaf isozymes and characterized for 58 descriptors. Research is expanding into RFLPs for the development of an usable genomic map. The pathogen detection program evaluates accession for 9 virus and viroid and 2 bacterial diseases. Infected accessions receive shoot-tip micrografting and thermotherapy to eliminate pathogens. All accessions are maintained as potted trees in aphid-proof screen- or greenhouses. Citrus seed, pollen and buds are being investigated for extended preservation under lowtemperature and cryostorage. Research investigations into in vitro culturing of explants have begun. A complete computerbased record of each accession is maintained on site and in the USDA-ARS Germplasm Resources Information Network (GRIN).
Persistent Identification of Instruments.
Creators: name: Stocker, Markus
name: Darroch, Louise
name: Krahl, Rolf
name: Habermann, Ted
name: Devaraju, Anusuriya
name: Schwardmann, Ulrich
name: D'Onofrio, Claudio
name: Häggström, Ingemar
Publisher: name: UNESCO/IOC
Year: 2020
Subjects: subject: Persistent Identification
subject: Instruments
subject: Metadata
subject: DOI
subject: Handle
subject: Parameter Discipline::Cross-discipline
subject: Data Management Practices::Metadata management
subject: Data Management Practices::Data transmission/networking

description: Instruments play an essential role in creating research data. Given the importance of instruments and associated metadata to the assessment of data quality and data reuse, globally unique, persistent and resolvable identification of instruments is crucial. The Research Data Alliance Working Group Persistent Identification of Instruments (PIDINST) developed a community-driven solution for persistent identification of instruments which we present and discuss in this paper. Based on an analysis of 10 use cases, PIDINST developed a metadata schema and prototyped schema implementation with DataCite and ePIC as representative persistent identifier infrastructures and with HZB (Helmholtz-Zentrum Berlin für Materialien und Energie) and BODC (British Oceanographic Data Centre) as representative institutional instrument providers. These implementations demonstrate the viability of the proposed solution in practice. Moving forward, PIDINST will further catalyse adoption and consolidate the schema by addressing new stakeholder requirements.
Generation of pure-state single photons with high heralding efficiency by using a three-stage nonlinear interferometer
Creators: name: Li, Jiamin
name: Su, Jie
name: Cui, Liang
name: Xie, Tianqi
name: Ou, Z. Y.
name: Li, Xiaoying
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We experimentally study a fiber-based three-stage nonlinear interferometer and demonstrate its application in generating heralded single photons with high efficiency and purity by spectral engineering. We obtain a heralding efficiency of 90% at a brightness of 0.039 photons/pulse. The purity of the source is checked by two-photon Hong-Ou-Mandel interference with a visibility of 95%+-6% (after correcting Raman scattering and multi-pair events). Our investigation indicates that the heralded source of single photons produced by the three-stage nonlinear interferometer has the advantages of high purity, high heralding efficiency, high brightness, and flexibility in wavelength and bandwidth selection.
description: 5 pages, 4 figures
title: Aspects of confused speech: a study of verbal interaction between confused and normal speakers
Creators: name: Shakespeare, Pamela
Publisher: name: The Open University
Year: 1996

description: This ethnographic study examines talk between normal and confused speakers. Most data derive from loosely structured research interviews, but use is also made of data from household situations. The analysis draws on theoretical traditions which examine everyday social interaction. From this perspective, confused speakers represent a case of naturally occurring deviance which allows for the investigation of 'normal talk' and how speakers deal with its absence. I focus on minimally active, moderately active, and very active confused speakers. All deviate from what ordinary members would commonsensically describe as normal, appropriate talk for the circumstances, in both what they say and how they talk. None of these groups can handle their own biographies, or routine common-sense knowledge, as effectively as ordinary members. However, minimally active speakers abrogate responsibility for context-sensitivity; moderately active speakers seem aware of context issues but may not act in a context-renewing way; while very active speakers seem not to be influenced by contextual issues but maintain a highly active part in the conversation. Normal speakers may take over the management of context for confused speakers, model context-sensitive talk, or withdraw their full participation. Frequently these strategies promote reasonably normal conversational appearances, but they do not entirely make good the impaired identity of confused speakers. My analysis suggests the definition of normal talk is constrained by how participants jointly construct social occasions. Normal speakers appreciate issues of context, acknowledging how it shapes and renews conversation. Confused speakers tend not to be context-sensitive in these ways, and their difficulties in this respect and in the generation of an identity appropriate to the event, creates problems within the conversation both for them and for others.
title: Being given a diagnosis of dementia: the experiences of people with dementia and people who care for someone with dementia
Creators: name: Taylor, Rachel Jane
Publisher: name: The Open University
Year: 1996

description: This study explores the issues raised for people with dementia and their carers when they receive a diagnosis of dementia. Previous research suggests that more people with dementia than other serious illnesses such as cancer will not be told their diagnosis. The implications of this for the way that people with dementia adjust psychologically to their situation are reviewed. It is suggested that the complex illness concept and the particular nature of dementia as an illness influence communication about it The research had three groups of participants. Twenty-six people caring for a relative with dementia completed a short survey. Two people with dementia and seven people caring for someone with dementia were interviewed face-to-face to gather in-depth information about their experiences of receiving and coping with a diagnosis. Grounded theory was used to analyse the interviews and a descriptive summary of the survey was produced. The survey confirmed that many people with dementia do not get told their diagnosis. The interviews described the issues raised for people with dementia, such as the feelings raised for them by having dementia and highlighted their ways of coping with dementia. The interviews with carers suggested that if sharing was an issue, the carers tried to strike a balance between remaining honest and protecting the person from the implications of the knowledge. Maintaining a sense of hope for the person seemed to be very important. A critical discussion of the methodology is presented. The implications for future research and the clinical relevance of the research are also discussed.
Gut-Associated Denitrification and In Vivo Emission of Nitrous Oxide by the Earthworm Families Megascolecidae and Lumbricidae in New Zealand
Creators: name: Wüst, Pia K.
name: Horn, Marcus A.
name: Henderson, Gemma
name: Janssen, Peter H.
name: Rehm, Bernd H.A.
name: Drake, Harold L.
Publisher: name: Washington, DC [u.a.] : American Soc. for Microbiology
Year: 2009
Subjects: subject: Acetylene
subject: Animals
subject: Bacterial Proteins
subject: Carbohydrates
subject: Carboxylic Acids
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: Previous studies have documented the capacity of European earthworms belonging to the family Lumbricidae to emit the greenhouse gas nitrous oxide (N2O), an activity attributed primarily to the activation of ingested soil denitrifiers. To extend the information base to earthworms in the Southern Hemisphere, four species of earthworms in New Zealand were examined for gut-associated denitrification. Lumbricus rubellus and Aporrectodea rosea (introduced species of Lumbricidae) emitted N2O, whereas emission of N2O by Octolasion cyaneum (an introduced species of Lumbricidae) and emission of N2O by Octochaetus multiporus (a native species of Megascolecidae) were variable and negligible, respectively. Exposing earthworms to nitrite or nitrate and acetylene significantly increased the amount of N2O emitted, implicating denitrification as the primary source of N2O and indicating that earthworms emitted dinitrogen (N2) in addition to N2O. The alimentary canal displayed a high capacity to produce N 2O when it was supplemented with nitrite, and alimentary canal contents contained large amounts of carbohydrates and organic acids indicative of fermentation (e.g., succinate, acetate, and formate) that could serve as sources of reductant for denitrification. nosZ encodes a portion of the terminal oxidoreductase used in denitrification. The nosZ sequences detected in the alimentary canals of L. rubellus and O. multiporus were similar to those retrieved from soil and were distantly related to sequences of uncultured soil bacteria and genera common in soils (i.e., Bradyrhizobium, Azospirillum, Rhodopseudomonas, Rhodospirillum, Pseudomonas, Oligotropha, and Sinorhizobium). These findings (i) suggest that the capacity to emit N2O and N 2 is a general trait of earthworms and not geographically restricted, (ii) indicate that species belonging to different earthworm families (i.e., Megascolecidae and Lumbricidae) may not have equal capacities to emit N 2O, and (iii) also corroborate previous findings that link this capacity to denitrification in the alimentary canal. Copyright © 2009, American Society for Microbiology. All Rights Reserved.
Total antioxidant capacity, vitamin A and E, and fatty acid content of human milk
Creators: name: Tijerina Saenz, Alexandra
Publisher: name: University of British Columbia
Year: 2011

description: Total antioxidant capacity (TAC) of human milk was used as a measurement to evaluate milk oxidative stability. The Oxygen Radical Absorbance Capacity (ORAC) assay was used to measure oxidative stability of human milk based on the advantages of the method, the photostability of the fluorescent probe fluorescein (FL), and the specificity for antioxidant activity against peroxyl radicals. The present study consisted of two sections; firstly to standardize and validate the ORACFL assay for use in determining TAC of human milk and second to determine potential relationships between different nutritional components and TAC levels o f mature human milk. The ORACFL assay was standardized and validated by determining the linearity, precision and accuracy of the assay and by determining an optimal dilution for human milk. Good linearity (R²>0.990) and precision (2.2%) were achieved and the assay accuracy was 95.4%, which was obtained by the recovery of Trolox standard after experimental analysis. Six different milk dilutions were used to evaluate milk TAC and a dilution of 200x was chosen for routine ORACFL analyses. A convenience sample consisting of human milk samples (n=77) was obtained from Canadian women at month 1 postnatally. Contents of milk fatty acids (FA), vitamin A (alltrans-retinol), vitamin E (α-tocopherol, [formula omitted]-tocopherol, and [formula omitted]-tocopherol), and TAC were measured and the biological activity of vitamin E and a total fatty acid unsaturation index (UI) were calculated. A total o f 60 milk samples were used in the final analyses, due to the presence of 17 samples with TAC values below detectable levels. According to the results, TAC of mature human milk was positively attributed to milk α-tocopherol (r= 0.439, p<0.001). Higher contents of α-tocopherol significantly increased milk oxidative stability. On the other hand, different contents of vitamin A or fatty acids or UI had no effect on milk TAC. These results suggested that oxidative stability of mature human milk could reflect the complex sum of different antioxidants and/or mechanisms, but confirmed the importance of the presence of antioxidants, such as vitamin E , in protecting against free radical-induced lipid peroxidation reactions.
Effects of microplastic ingestion on hydrogen production and microbiomes in the gut of the terrestrial isopod Porcellio scaber
Creators: name: Hink, Linda
name: Holzinger, Anja
name: Sandfeld, Tobias
name: Weig, Alfons R.
name: Schramm, Andreas
name: Feldhaar, Heike
name: Horn, Marcus A.
Publisher: name: Cold Spring Harbor : Cold Spring Harbor Laboratory
Year: 2022
Subjects: subject: Animals
subject: Eating
subject: Isopoda
subject: Microbiota
subject: Microplastics
subject: Plastics
subject: Polyesters
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: Microplastic (MP) pollution is an environmental burden. MP enters food webs via ingestion by macrofauna, including isopods (Porcellio scaber) in terrestrial ecosystems. However, MP-effects on the host and its gut microbiome are largely unknown. We tested the hypothesis that biodegradable (polylactic acid, PLA) and non-biodegradable (polyethylene terephthalate, PET polystyrene, PS) MP have contrasting effects on P. scaber mediated by changes of the associated gut microbiome. Although the isopods avoided food containing PS, isopod fitness after eight-week MP-exposure was unaffected. Qualitative and quantitative 16S rRNA gene and 16S rRNA analyses of gut microbiomes indicated general MP effects, MP-type specific indicator taxa, and stimulation by PLA compared to MP-free controls. Isopods emitted hydrogen, and its production increased and decreased after PLA-food and PET- or PS-food ingestion, respectively, relative to controls as indicated by microsensor measurements. Gut pH was unaffected by MP. We identified the gut of P. scaber as significant mobile source of reductant for soil microbiomes likely due to Enterobacteriaceae related fermentation activities that were stimulated by lactate generated during PLA-degradation. The findings suggest negative effects of PET and PS on gut fermentation, modulation of isopod hydrogen emissions by MP pollution, and the potential of MP to affect terrestrial food webs.
ISOZYMES REVEAL GENETIC RELATIONSHIPS IN BANANA GERMPLASM
Creators: name: Manshardt, R.M.
name: Lebot, V.
name: Aradhya, K.M.
name: Manshardt, R.M.
name: Lebot, V.
name: Aradhya, K.M.
Publisher: name: Unknown
Year: 1990
Subjects: Crop Production/Industries
Research and Development/Tech Change/Emerging Technologies

description: Isozyme variation was analyzed in a collection of banana cultivars to clarify genetic relationships among clones and to determine the affinities of Hawaiian bananas of early Polynesian introduction to other cultivated types. Enzymes were extracted from fresh young leaf tissues in modified Bousquet buffer at 4° C and separated by starch gel electrophoresis. Polymorphic enzymes, including ACO, MDH, PGI, and PGM, were well resolved in a continuous histidine citrate (pH 6.5) buffer system after 7 hr of electrophoresis at 15 V/cm. Isozyme variation was analyzed by cluster analysis, and the resulting groups generally corresponded well with the classification of Simmonds (1959) based on morphology. Three groups of Hawaiian cultivars were evident in this study. They were distinct from other clones and corresponded completely with a traditional classification, based on morphology, which distinguished ^Iholena', 'Maia Maoli' and 'Popoulu' groups. Cluster analysis placed the Hawaiian bananas squarely among the AAB cultivars, supporting Simmond's estimation of the genomic constitution of 'Maia Maoli' and 'Popoulu' cultivars, but contradicting his assignment of 'Iholena' bananas to the AAA group.
Old and new examples of surfaces of general type with $p_g=0$
Creators: name: Kulikov, Vik. S.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14J10

description: Surfaces of general type with geometric genus $p_g=0$, which can be given as Galois covering of the projective plane branched over an arrangement of lines with Galois group $G=(\mathbb Z/q\mathbb Z)^k$, where $k\geq 2$ and $q$ is a prime number, are investigated. The classical Godeaux surface, Campedelli surfaces, Burniat surfaces, and a new surface $X$ with $K_X^2=6$ and $(\mathbb Z/3\mathbb Z)^3\subset {Tors} (X)$ can be obtained as such coverings. It is proved that the group of automorphisms of a generic surface of the Campedelli type is isomorphic to $(\mathbb Z/2\mathbb Z)^3$. The irreducible components of the moduli space containing the Burniat surfaces are described. It is shown that the Burniat surface $S$ with $K_S^2=2$ has the torsion group ${Tors} (S)\simeq (\mathbb Z/2\mathbb Z)^3$, (therefore, it belongs to the family of the Campedelli surfaces), i.e., the corresponding statement in the papers of C. Peters "On certain examples of surfaces with $p_g=0$" in Nagoya Math. J. {\bf 66} (1977), and I. Dolgachev "Algebraic surfaces with $q=p_g=0$" in {\it Algebraic surfaces}, Liguori, Napoli (1977), and in the book of W. Barth, C. Peters, A. Van de Ven "Compact complex surfaces", p. 237, about the torsion group of the Burniat surface $S$ with $K_S^2=2$ is not correct.
DETECTION OF CYTOPLASMIC VARIABILITY IN Musa USING CHLOROPLAST DNA RFLPs
Creators: name: Gawel, N.
name: Jarret, R.L.
name: Gawel, N.
name: Jarret, R.L.
Publisher: name: Unknown
Year: 1990
Subjects: Crop Production/Industries
Research and Development/Tech Change/Emerging Technologies

description: Concerns over yield declines in bananas and plantain^ uue to the spread of Black Sigatoka disease in Musa have drawn attention to the collection of Musa germplasm and its use in conventional and biotechnological improvement programs. This report demonstrates the use of chloroplast DNA (cpDNA) restriction fragment length polymorphisms (RFLPs) for differentiating cytoplasms of various Musa clones. DNA was extracted from lyophilized leaf blade tissue and digested with either Eco RI, Hind III, Bam HI or Pst I. Southern blots onto nylon membranes were probed using radioactively labeled heterologous orchid and lettuce cpDNA fragments. Among the 14 Musa clones examined, a single M. balbisiana and four M. acuminata-type cytoplasms were differentiated. The ability to distinguish between cytoplasms and to place plants within a cytoplasmic grouping demonstrates the usefulness of RFLP technology in evaluating diversity and determining the ancestry of Musa clones.
Effect of salt stress on aerobic methane oxidation and associated methanotrophs; a microcosm study of a natural community from a non-saline environment
Creators: name: Ho, Adrian
name: Mo, Yongliang
name: Lee, Hyo Jung
name: Sauheitl, Leopold
name: Jia, Zhongjun
name: Horn, Marcus A.
Publisher: name: Amsterdam [u.a.] : Elsevier
Year: 2018
Subjects: subject: Global-change
subject: NaCl-Amendment
subject: pmoA
subject: Rice paddy
subject: Salinization
subject: Dewey Decimal Classification::500 | Naturwissenschaften::590 | Tiere (Zoologie)
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie
subject: Dewey Decimal Classification::500 | Naturwissenschaften::540 | Chemie

description: We investigated the response of aerobic methane oxidation and the associated methanotrophs to salt-stress in a NaCl gradient ranging from 0 M (un-amended reference) to 0.6 M NaCl (seawater salinity) using a rice paddy soil as a model system. Salt-stress significantly inhibited methanotrophic activity at > 0.3 M NaCl at 0.6 M NaCl amendment, methanotrophic activity fully ceased. MiSeq sequencing of the pmoA gene and group-specific qPCR analyses revealed that type Ia methanotroph (Methylobacter) appeared to be favored under salinity up to 0.3 M NaCl, increasing in numerical abundance, while the type Ib was adversely affected. This suggests niche differentiation within members of the gammaproteobacterial methanotrophs. Overall, rice paddy soil methanotrophs showed remarkable resistance to salt-stress.
title: FS Maria S. Merian - Fahrtbericht/Cruise report MSM 04-1
title: meridional overturning variability experiment (MOVE 2006), Fort de France- Fort de France, 02.12. - 21.12.2006
titleType: AlternativeTitle
Creators: name: Müller, Thomas J.
Publisher: name: IFM-GEOMAR, Kiel
Year: 2008

description: report
Should I Stay or Should I Go? Turnover among Public School Teachers and Principals
Creators: name: Marvel, John D.
Publisher: name: American University
Year: 2023

description: This dissertation uses data on public school teachers and principals to address three related research questions: 1. How do the predictors of turnover intention and actual turnover differ? 2. How do managerial constraints--in particular, constraints on public managers' ability to dismiss poorly performing employees--affect managers' turnover intentions and actual turnover decisions? 3. How do policymakers' efforts to induce bureaucrats' compliance with formal policy goals affect bureaucrats' turnover intentions? The dissertation comprises five chapters--an introduction, three empirical analyses (each of which will address one of the research questions listed above), and a conclusion. The first two empirical chapters use nationally representative, large-N data and non-experimental research designs to address their respective empirical questions. The third empirical chapter uses information collected from 12 semi-structured interviews with current and former public school teachers in the Washington, DC metropolitan area.Below, I begin with a discussion of why public employee turnover deserves analytical attention. The simplest justification for the dissertation is that turnover is costly to organizations, making the identification of its antecedents a worthwhile exercise. In my first empirical chapter, I illustrate how the use of turnover intention as a proxy for actual turnover in large-N research can produce misleading public management prescriptions. I do this using nationally representative data on public school teachers. In the dissertation's second empirical chapter, I transition to a focus on public school principals. Given that public school principals constitute a large class of public managers, it is useful to make them the focus of an analysis that tests whether managerial constraints are associated with managerial turnover decisions. Finally, in the dissertation's third empirical chapter, I narrow my analytical focus to teachers in the Washington, DC, public school system in order to more deeply explore the reasons underlying public sector employees' turnover behavior. I conclude with a discussion of the dissertation's implications for public management theory and public management prescription.
Acoustic horizons in axially symmetric relativistic accretion
Creators: name: Abraham, Hrvoje
name: Bilic, Neven
name: Das, Tapas K.
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Transonic accretion onto astrophysical objects is a unique example of analogue black hole realized in nature. In the framework of acoustic geometry we study axially symmetric accretion and wind of a rotating astrophysical black hole or of a neutron star assuming isentropic flow of a fluid described by a polytropic equation of state. In particular we analyze the causal structure of multitransonic configurations with two sonic points and a shock. Retarded and advanced null curves clearly demonstrate the presence of the acoustic black hole at regular sonic points and of the white hole at the shock. We calculate the analogue surface gravity and the Hawking temperature for the inner and the outer acoustic horizons.
description: 29 pages, 12 figures, significantly revised, sections on phonon propagation, phonon quantization, non-axisymmetric accretion and acoustic superradiance added, references added; to appear in Class. Quant. Grav. without section 2.4 which has been kept here for pedagogical reasons; section 2.4 slightly altered, misprints corrected
Should I Stay or Should I Go? Turnover among Public School Teachers and Principals
Creators: name: Marvel, John D.
Publisher: name: ProQuest
Year: 2023
Subjects: classificationCode: 39
subject: Education
classificationCode: 3904
subject: Specialist studies in education

description: This dissertation uses data on public school teachers and principals to address three related research questions: 1. How do the predictors of turnover intention and actual turnover differ? 2. How do managerial constraints--in particular, constraints on public managers' ability to dismiss poorly performing employees--affect managers' turnover intentions and actual turnover decisions? 3. How do policymakers' efforts to induce bureaucrats' compliance with formal policy goals affect bureaucrats' turnover intentions? The dissertation comprises five chapters--an introduction, three empirical analyses (each of which will address one of the research questions listed above), and a conclusion. The first two empirical chapters use nationally representative, large-N data and non-experimental research designs to address their respective empirical questions. The third empirical chapter uses information collected from 12 semi-structured interviews with current and former public school teachers in the Washington, DC metropolitan area.Below, I begin with a discussion of why public employee turnover deserves analytical attention. The simplest justification for the dissertation is that turnover is costly to organizations, making the identification of its antecedents a worthwhile exercise. In my first empirical chapter, I illustrate how the use of turnover intention as a proxy for actual turnover in large-N research can produce misleading public management prescriptions. I do this using nationally representative data on public school teachers. In the dissertation's second empirical chapter, I transition to a focus on public school principals. Given that public school principals constitute a large class of public managers, it is useful to make them the focus of an analysis that tests whether managerial constraints are associated with managerial turnover decisions. Finally, in the dissertation's third empirical chapter, I narrow my analytical focus to teachers in the Washington, DC, public school system in order to more deeply explore the reasons underlying public sector employees' turnover behavior. I conclude with a discussion of the dissertation's implications for public management theory and public management prescription.
Necroplanetology: Simulating the Tidal Disruption of Differentiated Planetary Material Orbiting WD 1145+017
Creators: name: Duvvuri, Girish M.
name: Redfield, Seth
name: Veras, Dimitri
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The WD 1145+017 system shows irregular transit features that are consistent with the tidal disruption of differentiated asteroids with bulk densities $< 4$ g cm$^{-3}$ and bulk masses $\lesssim 10^{21}$ kg (Veras et al., 2017; arXiv:1610.06926). We use the open-source N-body code REBOUND (Rein and Liu, 2011; arXiv:1110.4876) to simulate this disruption with different internal structures: varying the core volume fraction, mantle/core density ratio, and the presence/absence of a thin low-density crust. We allow the rubble pile to partially disrupt and capture lightcurves at a specific point during the disruption at cadences comparable to those from ground-based photometry. As a proof-of-concept we show that varying these structural parameters have observationally distinguishable effects on the transit light curve as the asteroid is disrupted and compare the simulation-generated lightcurves to data from Gary et al., 2017 (arXiv:1608.00026). With the caveat that our simulations do not model the sublimation in detail or account for its effects on orbital evolution, we find that a low core fraction and low mantle/core density ratio asteroid is most consistent with the stable transit feature present for multiple weeks circa April 2016 (referred to as G6121 in Gary et al., 2017 (arXiv:1608.00026) and A1 in Hallakoun et al., 2017 (arXiv:1702.05483). Connecting tidal disruption simulations to photometry suggests characteristics for the interior structure and composition of an exoplanetary body, information that is only possible because we are observing the death of the planetary system in action. All-sky survey missions such as TESS and LSST will be able to detect other systems like WD 1145+017, creating a sample of subjects for a new subfield of planetary science: necroplanetology.
description: Accepted for publication in the Astrophysical Journal on the 11th of March, 2020. 14 pages, 3 figures, 2 tables. Pre-proofs
title: The contribution of reorganised motor pathways to recovery of arm and hand function after stroke
Creators: name: Turton, Ailie Jean
Publisher: name: The Open University
Year: 1996

description: Stroke often disrupts the descending motor pathways controlling the upper limb with severe consequences for patients' hand function. Although some recover they are often slow and clumsy when using the affected hand. The mechanism underlying recovery is an unsettled question. Transcranial magnetic stimulation (TMS) was used to determine the changes in the connectivity and function of the corticospinal tract (CST) that are associated with improved motor performance in the recovering arm and hand. The study comprised four parts: 1. Task dependency of responses to TMS in recovered stroke patients. Eight patients, who had recovered some degree of hand function were tested for task dependence of short-latency EMG responses to TMS. Normal subjects were also tested. 2. Longitudinal investigation of recovery of voluntary movement of arm and hand after stroke. The relationship between the recovery of hand and arm function in a group of acute stroke patients (n=21) and the presence of short latency contralateral and ipsilateral EMG responses to TMS in four different upper limb muscles was investigated. 3. Ipsilateral responses in normal subjects. The results of the longitudinal study prompted further investigation of the presence of ipsilateral responses in proximal and distal muscles in fifteen normal subjects. 4. The contribution of CS input to production of force in proximal and distal upper limb muscles. Because patients did not always have responses to TMS in recovered proximal muscles, two further studies were carried out to clarify the contribution of CS input to production of force in proximal and distal upper limb muscles. First, the effect of voluntary contraction on response amplitudes in deltoid, biceps and ID1 were compared. Second, the effect of increasing stimulus intensity on recruitment of low threshold motor units was assessed for deltoid and ID1. In addition the change in response amplitude with increasing voluntary activity in the affected and unaffected shoulder muscles of three patients were compared.
Das Leben findet einen Weg : Erzeugung von Wasserstoff durch Mikroorganismen
Creators: name: Horn, Marcus A.
name: Rüppel, Nadine
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2022
Subjects: subject: Energieversorgung
subject: Transformation
subject: Erneuerbare Energien
subject: Energiewende
subject: Dewey Decimal Classification::300 | Sozialwissenschaften, Soziologie, Anthropologie::330 | Wirtschaft::333 | Boden- und Energiewirtschaft::333,7 | Natürliche Ressourcen, Energie und Umwelt

description: [no abstract available]
Influence of Laser Intensity Fluctuation on Single-Cesium Atom Trapping Lifetime in a 1064-nm Microscopic Optical Tweezer
Creators: name: Sun, Rui
name: Wang, Xin
name: Zhang, Kong
name: He, Jun
name: Wang, Junmin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: An optical tweezer composed of a strongly focused single-spatial-mode Gaussian beam of a red-detuned 1064-nm laser can confine a single-cesium (Cs) atom at the strongest point of the light intensity. We can use this for coherent manipulation of single-quantum bits and single-photon sources. The trapping lifetime of the atoms in the optical tweezers is very short due to the impact of the background atoms, the laser intensity fluctuation of optical tweezer and the residual thermal motion of the atoms. In this paper, we analyzed the influence of the background pressure, the trap frequency of optical tweezers and the parametric heating of the optical tweezer on the atomic trapping lifetime. Combined with the external feedback loop based on an acousto-optical modulator (AOM), the intensity fluctuation of the 1064-nm laser in the time domain was suppressed from $\pm$ 3.360$\%$ to $\pm$ 0.064$\%$, and the suppression bandwidth reached approximately 33 kHz. The trapping lifetime of a single Cs atom in the microscopic optical tweezer was extended from 4.04 s to 6.34 s.
description: 9 pages, 17 figures
Power Corrections to e+e- Dijet Event Shapes
Creators: name: Berger, Carola F.
name: Sterman, George
Publisher: name: arXiv
Year: 2003
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We discuss a class of event shapes for e+e- dijet events that include the thrust as a special case. Large logarithmic corrections to the corresponding cross sections can be resummed to all logarithmic orders at leading power. However, irrespective of the order up to which the perturbative expansion is calculated, it has to be supplemented by nonperturbative corrections due to its at best asymptotic nature. We find that the leading power corrections are universal for the class of event shapes discussed here. Based on these findings, we provide sample numerical predictions for the distributions of the new event shapes.
description: 3 pages, 1 figure; presented by C.F. Berger at the International Europhysics Conference on High-Energy Physics (HEP 2003), Aachen, Germany, 17-23 July 2003
Denitrification in soil aggregate analogues-effect of aggregate size and oxygen diffusion
Creators: name: Schlüter, Steffen
name: Henjes, Sina
name: Zawallich, Jan
name: Bergaust, Linda
name: Horn, Marcus A.
name: Ippisch, Olaf
name: Vogel, Hans-Jörg
name: Dörsch, Peter
Publisher: name: Lausanne : Frontiers Media S.A.
Year: 2018
Subjects: subject: Agrobacterium tumefaciens
subject: Anoxic aggregate centers
subject: Denitrification kinetics
subject: Greenhouse gas emissions
subject: Microbial hotspots
subject: Microsites
subject: Physically-based modeling
subject: Dewey Decimal Classification::300 | Sozialwissenschaften, Soziologie, Anthropologie::330 | Wirtschaft::333 | Boden- und Energiewirtschaft::333,7 | Natürliche Ressourcen, Energie und Umwelt

description: Soil-borne nitrous oxide (N2O) emissions have a high spatial and temporal variability which is commonly attributed to the occurrence of hotspots and hot moments for microbial activity in aggregated soil. Yet there is only limited information about the biophysical processes that regulate the production and consumption of N2O on microscopic scales in undisturbed soil. In this study, we introduce an experimental framework relying on simplified porous media that circumvents some of the complexities occuring in natural soils while fully accounting for physical constraints believed to control microbial activity in general and denitrification in particular. We used this framework to explore the impact of aggregate size and external oxygen concentration on the kinetics of O2 consumption, as well as CO2 and N2O production. Model aggregates of different sizes (3.5 vs. 7 mm diameter) composed of porous, sintered glass were saturated with a defined growth medium containing roughly 109 cells ml-1 of the facultative anaerobic, nosZ-deficient denitrifier Agrobacterium tumefaciens with N2O as final denitrification product and incubated at five different oxygen levels (0-13 vol-%). We demonstrate that the onset of denitrification depends on the amount of external oxygen and the size of aggregates. Smaller aggregates were better supplied with oxygen due to a larger surface-to-volume ratio, which resulted in faster growth and an earlier onset of denitrification. In larger aggregates, the onset of denitrification was more gradual, but with comparably higher N2O production rates once the anoxic aggregate centers were fully developed. The normalized electron flow from the reduced carbon substrate to N-oxyanions (edenit-/etotal- ratio) could be solely described as a function of initial oxygen concentration in the headspace with a simple, hyperbolic model, for which the two empirical parameters changed with aggregate size in a consistent way. These findings confirm the important role of soil structure on N2O emissions from denitrification by shaping the spatial patterns of microbial activity and anoxia in aggregated soil. Our dataset may serve as a benchmark for constraining or validating spatially explicit, biophysical models of denitrification in aggregated soil. © 2018 Schlüter, Henjes, Zawallich, Bergaust, Horn, Ippisch, Vogel and Dörsch.
Effects of thyroid inhibition and rearing temperature on zebrafish development
Creators: name: Reider, Masha
Publisher: name: American University
Year: 2023

description: Zebrafish development is a complex process that is highly dependent on the thyroid system. The purpose of this study was to examine the effects of thyroid hormone deprivation and rearing temperature on embryonic development. Embryos were exposed to different concentrations of methimazole (MMI), a known thyroid inhibitor, and maintained at either 28oC or 31oC. Changes in growth were assessed by determining changes in 4 parameters: eye size, inter-eye distance, body length, and spinal curvature. Initial experiments tested the effects of three MMI concentrations (0.1mM, 0,2mM, and 0.3mM) at three developmental ages (50, 60, and 72 hours postfertilization; hpf). Results from this study identified 60-72hpf as a critical developmental window for thyroid inhibitor sensitivity and 0.3mM as the MMI concentration that gave the most consistent results. Consequently, subsequent experiments exposed embryos to 0.3mM beginning at 0-1hpf. Embryos were removed from treatment hourly between 60 and 72hpf and placed in control water where they were allowed to develop until 72hpf, at which time they were euthanized and fixed for later analysis. Results of morphological measurements indicated a significant temperature effect for all growth parameters examined (p < 0.01), and that the embryonic thyroid system is functioning and capable of feedback mechanisms as early as 66 hpf. Further, we found that MMI significantly affected the development of retinal layers, where both temperature and MMI exposure caused significant effects at 72 hpf.
Effects of thyroid inhibition and rearing temperature on zebrafish development
Creators: name: Reider, Masha
Publisher: name: ProQuest
Year: 2023
Subjects: classificationCode: 52
subject: Psychology
subject: FOS: Psychology

description: Zebrafish development is a complex process that is highly dependent on the thyroid system. The purpose of this study was to examine the effects of thyroid hormone deprivation and rearing temperature on embryonic development. Embryos were exposed to different concentrations of methimazole (MMI), a known thyroid inhibitor, and maintained at either 28oC or 31oC. Changes in growth were assessed by determining changes in 4 parameters: eye size, inter-eye distance, body length, and spinal curvature. Initial experiments tested the effects of three MMI concentrations (0.1mM, 0,2mM, and 0.3mM) at three developmental ages (50, 60, and 72 hours postfertilization; hpf). Results from this study identified 60-72hpf as a critical developmental window for thyroid inhibitor sensitivity and 0.3mM as the MMI concentration that gave the most consistent results. Consequently, subsequent experiments exposed embryos to 0.3mM beginning at 0-1hpf. Embryos were removed from treatment hourly between 60 and 72hpf and placed in control water where they were allowed to develop until 72hpf, at which time they were euthanized and fixed for later analysis. Results of morphological measurements indicated a significant temperature effect for all growth parameters examined (p < 0.01), and that the embryonic thyroid system is functioning and capable of feedback mechanisms as early as 66 hpf. Further, we found that MMI significantly affected the development of retinal layers, where both temperature and MMI exposure caused significant effects at 72 hpf.
Off-Center Carbon Ignition in Rapidly Rotating, Accreting Carbon-Oxygen White Dwarfs
Creators: name: Saio, Hideyuki
name: Nomoto, Ken'ichi
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study the effect of stellar rotation on the carbon ignition in a carbon-oxygen white dwarf accreting CO-rich matter. Including the effect of the centrifugal force of rotation, we have calculated evolutionary models up to the carbon ignition for various accretion rates. The rotation velocity at the stellar surface is set to be the Keplerian velocity. The angular velocity in the stellar interior has been determined by taking into account the transport of angular momentum due to turbulent viscosity. We have found that an off-center carbon ignition occurs even when the effect of stellar rotation is included if the accretion rate is sufficiently high; the critical accretion rate for the off-center ignition is hardly changed by the effect of rotation. Rotation, however, delays the ignition;i.e., the mass coordinate of the ignition layer and the total mass at the ignition are larger than those for the corresponding no-rotating model. The result supports our previous conclusion that a double-white dwarf merger would not be a progenitor of a SN Ia.
description: 18 pages, 6 figures; To appear in the Astrophysical Journal, 1 November 2004, V615 issue