cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Contact Inequality -- First Contact Will Likely Be With An Older Civilization
Creators: name: Kipping, David
name: Frank, Adam
name: Scharf, Caleb
Publisher: name: arXiv
Year: 2020
Subjects: subject: Popular Physics (physics.pop-ph)
subject: FOS: Physical sciences

description: First contact with another civilization, or simply another intelligence of some kind, will likely be quite different depending on whether that intelligence is more or less advanced than ourselves. If we assume that the lifetime distribution of intelligences follows an approximately exponential distribution, one might naively assume that the pile-up of short-lived entities dominates any detection or contact scenario. However, it is argued here that the probability of contact is proportional to the age of said intelligence (or possibly stronger), which introduces a selection effect. We demonstrate that detected intelligences will have a mean age twice that of the underlying (detected + undetected) population, using the exponential model. We find that our first contact will most likely be with an older intelligence, provided that the maximum allowed mean lifetime of the intelligence population, $τ_{\rm max}$, is $>e$ times larger than our own. Older intelligences may be rare but they disproportionality contribute to first contacts, introducing what we call a 'contact inequality', analogous to wealth inequality. This reasoning formalizes intuitional arguments and highlights that first contact would likely be one-sided, with ramifications for how we approach SETI.
description: Published in the International Journal of Astrobiology. Formatted with aastex6.2
Competition, Reputation and Cheating
Creators: name: Vanin, Paolo
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2009
Subjects: SECS-P/01 Economia politica

description: Under repeated market interaction, reputation and competition may drive out of the market those firms that do not comply with their quality promises. One may thus presume that competitive pressure improves average market quality. This paper shows that the opposite may be true in an endogenous entry, repeated interaction, linear demand oligopoly model, in which introductory prices may be used as quality signals. Cheating firms may enter the market, fool even rational consumers, and exit the market when discovered, implying a failure of the basic reputation mechanism and an increasing time path of prices. Markets for closer substitutes tend to have a lower initial average quality and less trusting consumers, whereas the number of competitors has no clear relationship with average quality.
On the political economy of income redistribution and crime
Creators: name: Imrohoroglu, Ayse
name: Merlo, Antonio
name: Rupert, Peter
name: Imrohoroglu, Ayse
name: Merlo, Antonio
name: Rupert, Peter
Publisher: name: Unknown
Year: 1996
Subjects: Political Economy

description: In this paper we consider a general equilibrium model where heterogeneous agents specialize either in legitimate market activities or in criminal activities and majority rule determines the share of income redistributed and the expenditures devoted to the apprehension of criminals. We calibrate our model to the U.S. economy in 1990, and we conduct simulation exercises to evaluate the effectiveness of expenditures on police protection and income redistribution at reducing crime. We find that while expenditures on police protection reduce crime, it is possible for the crime rate to increase with redistribution. We also show that economies that adopt relatively more generous redistribution policies may have either higher or lower crime rates than economies with relatively less generous redistribution policies, depending on the characteristics of their wage distribution and on the efficiency of their apprehension technology.
Observation of Strong Quantum Depletion in a Gaseous Bose-Einstein Condensate
Creators: name: Xu, K.
name: Liu, Y.
name: Miller, D. E.
name: Chin, J. K.
name: Setiawan, W.
name: Ketterle, W.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We studied quantum depletion in a gaseous Bose-Einstein condensate. An optical lattice enhanced the atomic interactions and modified the dispersion relation resulting in strong quantum depletion. The depleted fraction was directly observed as a diffuse background in the time-of-flight images. Bogoliubov theory provided a semi-quantitative description for our observations of depleted fractions in excess of 50%.
description: Replaced with accepted version in PRL
Competition, Reputation and Compliance
Creators: name: Vanin, Paolo
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2009
Subjects: SECS-P/01 Economia politica

description: This paper displays a linear demand oligopoly model, in which firms endogenously decide whether to enter the market and whether to specialize on high or low quality products, and then repeatedly interact to sell experience goods.
It shows that the intuition that low and rising prices grant compliance with quality promises extends to this setting, provided that high quality is sufficiently important to buyers.
The pharmacology of nucleoside analogues in herpesvirus infection
Creators: name: Smyrnis, Elie Mario
Publisher: name: University of British Columbia
Year: 2009

description: The pharmacological aspect of anti-herpesvirus (HHV) research has entered a new era concomitant with the introduction of the nucleoside analogue-class of antiviral agent. Recent accession to the specificity of these agents has provided not only substantial improvements in the treatment and prophylaxis of many different HHV infections, but to enhancements in the methods used to diagnose and further study these virus-induced illnesses as well. The disparate applications of such compounds are perhaps best illustrated by the thymidine kinase (tk-dependent anti-HHV nucleoside analogues -- agents which, by virtue of their selective uptake and metabolism, have been used both chemotherapeutically and as molecular indicators of the virus itself. It is clear that a fundamental principle in determining an antiviral's pharmacotherapeutic relevance and of gauging its potential as a diagnostic indicator of disease lies in the ability to accurately detect and quantitate these agents in complex biological matrices. In the present study, radioiodinated 1-β-D-arabino-furanosyl- E-5-(2-iodovinyl)uracil ([*I]-IVaraU) was used to develop an autoradiographic technique (PA/IP) that rapidly and accurately demonstrated thetk- (and thymidylate kinase)-dependent metabolism of this antiviral agent. [*I]-IVaraU-PA/ IP was also used to detect antiviral-resistant HHV variants in somatic cell cultures, to examine the growth of HSV in primary cultures of mammalian CNS glial cells and to demonstrate the uptake and metabolism of 9-(4-hydroxy-3-hydroxy-methylbut- 1-yl)guanine (PCV) in a human neural (SW) cell line. We further demonstrate limited in vivo utility of [*I]-IVaraU for detecting HHV in tissue autoradiographs of CNS sections prepared from a rabbit encephalitis model. The use of this agent as a radiodiagnostic indicator of HSE in intact animals using external gamma camera imaging, however, was found to be largely unreliable. Finally, techniques in ESI mass spectrometry (both independent from and in combination with RP-IP HPLC - including the development of requisite volatile buffer systems) were used to determine that the PCV-TP synthesized by HSV(tk+) type 1-infected-PCV (10 μM and 1 µM)-treated SW cells after a 6 H drug treatment to be 11500 pmole•(106)-1 and 2440 pmole•(1O6)-1 SW cells, respectively, and that the intracellular stability of PCV-TP in this culture system was roughly 16.5 H. These determinations were made by monitoring the nucleotide→ortho/pyrophosphate transitions. We conclude that this technique can be developed further, into a method for monitoring the therapeutic efficacy of this and possibly other antiviral compounds.
A Stochastic Optimal Control Model of Pollution Abatement
Creators: name: Dragone, Davide
name: Lambertini, Luca
name: Leitmann, George
name: Palestini, Arsen
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2009
Subjects: SECS-P/01 Economia politica

description: We model a dynamic monopoly with environmental externalities,investigating the adoption of a tax levied on the firm's instantaneous contribution to the accumulation of pollution. The latter process is subject to a shock, which is i.i.d. across instants. We prove the existence of an optimal tax rate such that the monopoly replicates the same steady state welfare level as under social planning. Yet, the corresponding output level, R&D investment for environmental friendly technologies and surplus distribution necessarily differ from the socially optimal ones.
Is Competition for FDI Bad for Regional Welfare?
Creators: name: Amerighi, Oscar
name: De Feo, Giuseppe
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2009
Subjects: SECS-P/01 Economia politica

description: We investigate the impact on regional welfare of policy competition for FDI when a multinational firm can strategically react to differences in statutory corporate tax rates and shift taxable profits to lower-tax jurisdictions. We show that competing governments may have an incentive to tax discriminate between domestic and multinational firms even in the presence of profit shifting opportunities for the latter. In particular, tax competition leads to higher welfare for the region as a whole than lump-sum subsidy competition when the difference in statutory corporate tax rates and/or their average is high enough. We also find that policy competition increases regional welfare by changing the firm's investment decision when profit shifting motivations might induce the firm to locate in the least profitable country.
title: Bernhard Hübler
title: 1835-1912
titleType: Subtitle
Creators: name: Huber, Max
Publisher: name: Schulthess & Co.
Year: 1912
Subjects: subject: 920 Biografien, Genealogie, Insignien
subject: Nachruf
subject: Hübler, Bernhard
subject: Cottbus

description: Separat-Abdruck aus der Schweizerischen Juristen-Zeitung, IX. Jahrg., Heft 1
Essays in Family Business
Creators: name: Tetzlaff, Elizabeth
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2024
Subjects: Family Business
Enterprising Families
Social Constructionism
Sensemaking-Sensegiving
Symbolic Interactionism
Organizational Culture
Family Leaders
Mental Health

description: Family businesses are important contributors to capitalist economies yet transferring the business from one generation to the next continues to have a high failure rate. The literature consistently shows that the owning family is a significant contributing factor that shapes succession and other organizational outcomes. Previous research studying the business family has focused on the firm to infer the family's influence, falling short of apprehending how the family shapes the family business. To address this gap, the three essays in this dissertation use a family-first approach to better understand how families differ in the ways they view, interpret, and make sense of their family business. The focus of the project is to critically examine how individual family members attribute meaning to the family business and how business families interactions create shared meaning that influence how they shape the family business. I begin with a critical review paper that used symbolic interactionism and sensemaking-sensegiving to show that authority, culture, and discourse are social processes that influence the meaning of the family business and family members' behaviour in the family business. Next, I examined how families made sense of change triggers when managing their family enterprise culture. Finally, I examined interdisciplinary literature to explore how mental health conditions of family leaders can act as a trigger of change that impacts the family and the family business. To conclude, these three essays offer hindsight, insight, and foresight into how capturing how business family members create shared meaning can enrich our understanding of differences across family businesses.
Spitzer observations of the Hyades: Circumstellar debris disks at 625 Myr of age
Creators: name: Cieza, Lucas
name: Cochran, William D.
name: Augereau, Jean-Charles
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We use the Spitzer Space Telescope to search for infrared excess at 24, 70, and 160 micron due to debris disks around a sample of 45 FGK-type members of the Hyades cluster. We supplement our observations with archival 24 and 70 micron Spitzer data of an additional 22 FGK-type and 11 A-type Hyades members in order to provide robust statistics on the incidence of debris disks at 625 Myr of age an era corresponding to the late heavy bombardment in the Solar System. We find that none of the 67 FGK-type stars in our sample show evidence for a debris disk, while 2 out of the 11 A-type stars do so. This difference in debris disk detection rate is likely to be due to a sensitivity bias in favor of early-type stars. The fractional disk luminosity, L_dust/L*, of the disks around the two A-type stars is ~4.0E-5, a level that is below the sensitivity of our observations toward the FGK-type stars. However, our sensitivity limits for FGK-type stars are able to exclude, at the 2-sigma level, frequencies higher than 12% and 5% of disks with L_dust/L* > 1.0E-4 and L_dust/L* > 5.0E-4, respectively. We also use our sensitivity limits and debris disk models to constrain the maximum mass of dust, as a function of distance from the stars, that could remain undetected around our targets.
description: 33 pages, 11 figures, accepted by ApJ
Class elicitation session
Creators: name: O'Hagan, Zachary James
name: Rolle, Nicholas Revett
name: Russell, Kamala Rose
name: Sande, Hannah Leigh
name: Zapana Almanza, Hector
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2016
Subjects: Aymara language

description: Wh-questions (NR); distant vs. recent past (ZO); verbal morphology in imperatives (KR); relative clauses (HS)
The Spin Periods and Rotational Profiles of Neutron Stars at Birth
Creators: name: Ott, Christian D.
name: Burrows, Adam
name: Thompson, Todd A.
name: Livne, Eli
name: Walder, Rolf
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present results from an extensive set of one- and two-dimensional radiation-hydrodynamic simulations of the supernova core collapse, bounce, and postbounce phases, and focus on the protoneutron star (PNS) spin periods and rotational profiles as a function of initial iron core angular velocity, degree of differential rotation, and progenitor mass. For the models considered, we find a roughly linear mapping between initial iron core rotation rate and PNS spin. The results indicate that the magnitude of the precollapse iron core angular velocities is the single most important factor in determining the PNS spin. Differences in progenitor mass and degree of differential rotation lead only to small variations in the PNS rotational period and profile. Based on our calculated PNS spins, at ~ 200-300 milliseconds after bounce, and assuming angular momentum conservation, we estimate final neutron star rotation periods. We find periods of one millisecond and shorter for initial central iron core periods of below ~ 10 s. This is appreciably shorter than what previous studies have predicted and is in disagreement with current observational data from pulsar astronomy. After considering possible spindown mechanisms that could lead to longer periods we conclude that there is no mechanism that can robustly spin down a neutron star from ~ 1 ms periods to the "injection" periods of tens to hundreds of milliseconds observed for young pulsars. Our results indicate that, given current knowledge of the limitations of neutron star spindown mechanisms, precollapse iron cores must rotate with periods around 50-100 seconds to form neutron stars with periods generically near those inferred for the radio pulsar population.
description: 31 pages, including 20 color figures. High-resolution figures available from the authors upon request. Accepted to ApJ
title: Dr. Eduard Killias
title: eine biographische Skizze
titleType: Subtitle
Creators: name: Lorenz, Paul
Publisher: name: Gebrüder Casanova
Year: 1892
Subjects: subject: 920 Biografien, Genealogie, Insignien
subject: Nachruf
subject: Killias, Eduard
subject: Chur

description: Sonderdruck aus dem XXXV. Jahresbericht der naturforschenden Gesellschaft Graubünden in Chur
Disorder Induced Localized States in Graphene
Creators: name: Pereira, Vitor M.
name: Guinea, F.
name: Santos, J. M. B. Lopes dos
name: Peres, N. M. R.
name: Neto, A. H. Castro
Publisher: name: arXiv
Year: 2005
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We consider the electronic structure near vacancies in the half-filled honeycomb lattice. It is shown that vacancies induce the formation of localized states. When particle-hole symmetry is broken, localized states become resonances close to the Fermi level. We also study the problem of a finite density of vacancies, obtaining the electronic density of states, and discussing the issue of electronic localization in these systems. Our results also have relevance for the problem of disorder in d-wave superconductors.
description: Replaced with published version. 4 pages, 4 figures. Fig. 1 was revised
Do Ecopassages Affect Daily Movements and Home Ranges of Blanding's Turtles (Emydoidea blandingii)?
Creators: name: O'Halloran, Andrea
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2024
Subjects: Road Ecology
Management
Species at risk
Home Range
Reptile
Mitigation Solutions
Wildlife Passages
Blanding's Turtles
Movement

description: Global biodiversity has been decreasing at an alarming rate due to factors such as over-exploitation of species, habitat loss, and fragmentation. A major contributor to habitat loss and fragmentation is road development. Massive road networks span our landscapes and contribute to loss of biodiversity in many ways, such as road mortality. Mitigation techniques, such as ecopassages and exclusion fencing, are implemented across the world to reduce road mortality, though few studies have explored their effectiveness at maintaining movement. Within the Canadian Nuclear Laboratories (CNL) in Chalk River, Ontario, Canada, there is a small population of Blanding's turtles (Emydoidea blandingii), a federally protected species. In 2014/15, a radiotelemetry study was conducted to assess habitat use and movement patterns of this species at CNL. Seven ecopassages and exclusion fencing were installed along the main access roads following this study. I wished to determine whether the installation of ecopassages at CNL has improved habitat connectivity and spatial distribution of Blanding's turtles. Thus, I repeated the radiotelemetry study after the installation of the ecopassages. Movement patterns and home ranges were not significantly impacted by ecopassage presence, however, population spatial distribution decreased after ecopassage installation. Considering the widespread use of ecopassages by animals, these findings highlight the need for further investigation into the effectiveness of ecopassages for reptiles prior to continued application of this road mitigation strategy.
Matching conditions for a brane of arbitrary codimension
Creators: name: Charmousis, Christos
name: Zegers, Robin
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present matching conditions for distributional sources of arbitrary codimension in the context of Lovelock gravity. Then we give examples, treating maximally symmetric distributional p-branes, embedded in flat, de Sitter and anti-de Sitter spacetime. Unlike Einstein theory, distributional defects of locally smooth geometry and codimension greater than 2 are demonstrated to exist in Lovelock theories. The form of the matching conditions depends on the parity of the brane codimension. For odd codimension, the matching conditions involve discontinuities of Chern-Simons forms and are thus similar to junction conditions for hypersurfaces. For even codimension, the bulk Lovelock densities induce intrinsic Lovelock densities on the brane. In particular, this results in the appearance of the induced Einstein tensor for p>2. For the matching conditions we present, the effect of the bulk is reduced to an overall topological solid angle defect which sets the Planck scale on the brane and to extrinsic curvature terms. Moreover, for topological matching conditions and constant solid angle deficit, we find that the equations of motion are obtained from an exact p+1 dimensional action, which reduces to an induced Lovelock theory for large codimension. In essence, this signifies that the distributional part of the Lovelock bulk equations can naturally give rise to induced gravity terms on a brane of even co-dimension. We relate our findings to recent results on codimension 2 branes.
description: Published version, 40 pages, 2 figures (1 extra), added explanatory comments and remarks. Examples section altered
Sexual Assault Disclosure: Exploring the Disclosure Experiences of Women Who Have Been Sexually Assaulted
Creators: name: Bogaert, Holiday
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2024
Subjects: Sexual assault
Rape myth
Disclosure
Ideology
Violence
Gender norms

description: Sexual assault is severely underreported in today's society. Despite extensive research on sexual assault statistics and reporting rates, limited attention has been given to women's experiences of disclosure. Additionally, factors contributing to these experiences have not been highlighted. In response to this deficit, this thesis seeks to understand the experiences of women who disclose sexual assault to informal or formal support and the contexts surrounding disclosure. To do this, the following research question was answered: What ideologies and ideological assumptions, gendered norms, patriarchal norms, and violence, are present during and after women disclose their instances of sexual assault, and how does this shape their experiences of disclosure? Furthermore, what effect do these assumptions have on women's experiences of disclosure and after disclosure, change is self-perspective, lasting violence, etc.?
KwARG: Parsimonious reconstruction of ancestral recombination graphs with recurrent mutation
Creators: name: Ignatieva, Anastasia
name: Lyngsø, Rune B.
name: Jenkins, Paul A.
name: Hein, Jotun
Publisher: name: arXiv
Year: 2020
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: FOS: Biological sciences

description: The reconstruction of possible histories given a sample of genetic data in the presence of recombination and recurrent mutation is a challenging problem, but can provide key insights into the evolution of a population. We present KwARG, which implements a parsimony-based greedy heuristic algorithm for finding plausible genealogical histories (ancestral recombination graphs) that are minimal or near-minimal in the number of posited recombination and mutation events. Given an input dataset of aligned sequences, KwARG outputs a list of possible candidate solutions, each comprising a list of mutation and recombination events that could have generated the dataset; the relative proportion of recombinations and recurrent mutations in a solution can be controlled via specifying a set of 'cost' parameters. We demonstrate that the algorithm performs well when compared against existing methods. The software is made available on GitHub.
description: 18 pages, 12 figures; accepted for publication in Bioinformatics
Voltage dependence of Landau-Lifshitz-Gilbert damping of a spin in a current driven tunnel junction
Creators: name: Katsura, Hosho
name: Balatsky, Alexander V.
name: Nussinov, Zohar
name: Nagaosa, Naoto
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We present a theory of Landau-Lifshitz-Gilbert damping $α$ for a localized spin ${\vec S}$ in the junction coupled to the conduction electrons in both leads under an applied volatege $V$. We find the voltage dependence of the damping term reflecting the energy dependence of the density of states. We find the effect is linear in the voltage and cotrolled by particle-hole asymmetry of the leads.
description: 6 pages, 3 figures
Deriving the mass distribution of M87 from globular clusters
Creators: name: Wu, Xiaoan
name: Tremaine, Scott
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We describe a maximum-likelihood method for determining the mass distribution in spherical stellar systems from the radial velocities of a population of discrete test particles. The method assumes a parametric form for the mass distribution and a non-parametric two-integral distribution function. We apply the method to a sample of 161 globular clusters in M87. We find that the mass within 32 kpc is $(2.4\pm0.6)\times 10^{12} $M${_\odot}$, and the exponent of the density profile $ρ\propto r^{-α}$ in the range 10-100 kpc is $α=1.6\pm0.4$.The energy distribution suggests a few kinematically distinct groups of globular clusters. The anisotropy of the globular-cluster velocity distribution cannot be determined reliably with the present data. Models fitted to an NFW potential yield similar mass estimates but cannot constrain the concentration radius $r_c$ in the range 10-500 kpc.
description: 32 pages, 12 figures, accepted to publish in ApJ
Vers une compréhension phénoménologique du stress traumatique secondaire en milieu de psychiatrie légale
Creators: name: Seyer-Forget, Charlène
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2024
Subjects: Psychiatrie légale
Trauma secondaire
Infirmières

description: Les écrits scientifiques indiquent invariablement que le personnel infirmier exerçant en milieux psychiatriques est particulièrement à risque de subir des actes de violence, notamment de la part des patients qui y sont hospitalisés. Le projet de recherche repose sur le besoin de comprendre comment le personnel infirmier, exposé à des conditions pouvant mener au stress traumatique secondaire (STS), administre des soins en concordance (ou non) avec les principes éthiques à leurs patients alors que ces derniers viennent de commettre une agression sur une tierce personne (un collègue). Le cadre théorique utilisé pour cette recherche s'appuie sur les travaux de Kristeva, Goffman, Foucault et Lazarus et Folkman. L'analyse interprétative phénoménologique est le devis méthodologique retenu pour analyser et interpréter les éléments contextuels que l'infirmière vit et subit alors qu'elle est confrontée régulièrement au phénomène du STS dans son milieu de pratique. Le vécu phénoménologique des infirmiers et infirmières partagés par les participants de cette étude peut être regroupé sous trois catégories soit 1) les éléments culturels du contexte psycho légal sécuritaire, 2) l'agression et ses conséquences et 3) les stratégies déployées pour gérer les conséquences de l'agression. Les résultats de l'étude ont permis de constater en quoi la qualité des soins est sous optimale en milieu psycho légal sécuritaire. Des éléments individuels, interpersonnels, culturels et systémiques interfèrent dans les processus relationnels et affectent les soins infirmiers prodigués. Les stratégies que les infirmières de cette étude utilisent pour assurer des soins de qualité auprès des patients agresseurs sont axées sur la rationalisation, les émotions, l'action, le système et sont utilisées par les infirmières afin d'actualiser leur rôle professionnel et ce malgré des dommages collatéraux important pour elles-mêmes. La gestion de l'émotion et de sa cause, l'abjection, est une priorité pour les infirmières en milieu psycho légal sécuritaire dans un contexte qui tend à invalider leur vécu émotionnel. Des stratégies primaires, secondaires et tertiaires doivent être déployées afin de soutenir les infirmières et leurs collègues dans des situations de soins émotionnellement exigeantes pouvant engendrer des traumatismes.
An Explanation for the soft X-ray excess in AGN
Creators: name: Crummy, J
name: Fabian, AC
name: Gallo, L
name: Ross, RR
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a large sample of type 1 active galactic nuclei (AGN) spectra taken with XMM-Newton, and fit them with both the conventional model (a power law and black body) and the relativistically-blurred photoionized disc reflection model of Ross and Fabian (2005). We find the disc reflection model is a better fit. The disc reflection model successfully reproduces the continuum shape, including the soft excess, of all the sources. The model also reproduces many features that would conventionally be interpreted as absorption edges. We are able to use the model to infer the properties of the sources; specifically that the majority of black holes in the sample are strongly rotating and that there is a deficit in sources with an inclination > 70 degrees. We conclude that the disc reflection model is an important tool in the study of AGN X-ray spectra.
description: 16 pages, MNRAS accepted
An efficient piperazine-based tertiary poly(amic acid) heterogeneous catalyst to prepare pyrrolidinone scaffolds
Creators: name: Dewi, Rita Sharmila
name: Zaharani, Lia
name: Johan, Mohd Rafie
name: Khaligh, Nader Ghaffari
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Biochemistry
subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Plant Biology
subject: Virology

description: Given the abundance of functional groups, meso- and macro-pores, and a high surface area, the piperazine-based poly(amic acid) was employed as a heterogeneous catalyst in the multicomponent reaction to prepare pyrrolidinone scaffolds in a green solvent, acting as a medium for mass transfer and crystallization solvent. The important parameters of the reaction were investigated to find the optimal reaction conditions. A conversion of 100% was obtained at reflux conditions within 30–100 min using a catalytic amount of 200 mg of piperazine-based poly(amic acid) per 2 mmol of reactants (100 mg of cat./1 mmol of reactant). The piperazine-based poly(amic acid) exhibited high recyclability and the recovered catalyst could be used in successive runs without worthy loss in its activity. This work revealed the catalytic activity of the piperazine-based poly(amic acid) as a promising functional polymeric heterogeneous catalyst for organic synthesis.
Design, synthesis and structural studies of oxathiepine, benzo[b][1, 4]thiazine and quinolin-4-ol derivative based on 3-bromo-4-hydroxy-7-methoxyquinolin-2-one
Creators: name: Hassanien, Alaa E.
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Biotechnology
subject: Chemical Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified
subject: Information Systems not elsewhere classified
subject: Inorganic Chemistry
subject: FOS: Chemical sciences
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology

description: 4-Hydroxy-7-methoxyquinolin-2-one (1) and its derivative 3-bromo-4-hydroxy-7-methoxyquinolin-2-one (2) serve as valuable intermediates for the synthesis of advanced hetero-compounds. The reactivity of compound (2) has been verified through multiple substitution reactions. Their reactions with 2-mercaptoacetic acid, 3-mercaptopropanoic acid, or 2-aminobenzoic acid resulted in the corresponding hetero-compounds with high yields. The synthesized compounds underwent thorough examination via elemental and spectral analyses. Additionally, DFT calculations confirmed their structures in accordance with spectral investigations. Furthermore, the study delved into the global chemical reactivity parameters.
The incidence of post-harvest problems among small farmers surveyed in three regions of the Limpopo Province
Creators: name: Randela, Rendani
name: Randela, Rendani
Publisher: name: Unknown
Year: 2003
Subjects: Crop Production/Industries

description: High yielding varieties and new production technology have vastly increased the world's agricultural production and provided rural incomes and affordable food for large parts of the population. While production research has received considerable attention, until recently, post harvest activities have not received much attention. Post harvest research has significant contribution towards the alleviation of poverty, food insecurity and the sustainable use of resources. The objective of the paper is to assess the post-harvest constraints affecting main staple grain crops in three regions of the Limpopo Province. Some of the most common post harvest constraints revealed by the study are, weevils, rodents and transport for produce from the field to home Chemical, biological and indigenous control measures are used by the smallholder farmers to alleviate some of the post harvest constraints. The results of the study seem to indicate that more research work should be done especially on the use of indigenous knowledge towards the alleviation of post harvest constraints.
Comparative advantage of organic wheat production in the Western Cape
Creators: name: Mahlanza, B.
name: Mendes, E.
name: Vink, Nick
name: Mahlanza, B.
name: Mendes, E.
name: Vink, Nick
Publisher: name: Unknown
Year: 2003
Subjects: Crop Production/Industries

description: In a context in which the framework of agricultural policy and business is changing radically the objective of the government and farmers should be to support the development of systems that look likely to be winners in the future. As a result this paper uses a Policy Analysis Matrix (PAM) to determine whether wheat production would have a comparative advantage if produced under organic practices. The paper starts by analysing the comparative advantage of wheat under conventional practices, and later contrasts conventional with organic practices. The results of the analyses mainly indicate a comparative advantage for wheat grown under organic practices especially when the social cost benefit ratio (SCB) is incorporated into the analyses. This is because the domestic resource cost (DRC) criterion that is used by the PAM is confirmed to understate the social profitability of systems that use domestic factors intensively like organic wheat systems and favours systems that use less of these factors like conventional systems. The results also show the existence of distortions in the market even if wheat were to be produced under organic practises, although these are shown to be less than for wheat produced under conventional practices.
Deoxygenation of benzylphenyl sulfones using 1,2-bis(diphenylphosphino)ethane (dppe)/NBS under metal-free conditions
Creators: name: Joshi, Asha
name: Singh, Sandeep
name: Iqbal, Zafar
name: Rai, Prachi
name: De, Saroj Ranjan
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Biochemistry
subject: Medicine
subject: Pharmacology
subject: Environmental Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Astronomical and Space Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Developmental Biology
subject: Marine Biology
subject: Science Policy

description: An efficient route for the chemoselective deoxygenation of benzylphenyl sulfones to the corresponding sulfides has been developed using a mixture of 1,2-bis(diphenylphosphino)ethane(dppe) and NBS as an effective promoter. This is the first development on the deoxygenation of diverse benzylphenyl sulfones under metal-free conditions. The mild reaction conditions, formation of the water soluble by-product and tolerance of a wide range of functional groups promote its broad applications in organic synthesis.
Impedance of a sphere oscillating in an elastic medium with and without slip
Creators: name: Norris, Andrew N.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The dynamic impedance of a sphere oscillating in an elastic medium is considered. Oestreicher's formula for the impedance of a sphere bonded to the surrounding medium can be expressed simply in terms of three lumped impedances associated with the displaced mass and the longitudinal and transverse waves. If the surface of the sphere slips while the normal velocity remains continuous, the impedance formula is modified by adjusting the definition of the transverse impedance to include the interfacial impedance.
description: 10 pages, 2 figures
Current jumps in flat band ladders with Dzyaloshinskii-Moriya interactions
Creators: name: Acevedo, S.
name: Pujol, P.
name: Lamas, C. A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Localized magnons states, due to flat bands in the spectrum, is an intensely studied phenomenon and can be found in many frustrated magnets of different spatial dimensionality. The presence of Dzyaloshinskii-Moriya (DM) interactions may change radically the behavior in such systems. In this context, we study a paradigmatic example of a one-dimensional frustrated antiferromagnet, the sawtooth chain in the presence of DM interactions. Using both path integrals methods and numerical Density Matrix Renormalization Group, we revisit the physics of localized magnons and determine the consequences of the DM interaction on the ground state. We have studied the spin current behavior, finding three different regimes. First, a Luttinger-liquid regime where the spin current shows a step behavior as a function of parameter $D$, at a low magnetic field. Increasing the magnetic field, the system is in the Meissner phase at the $m = 1/2$ plateau, where the spin current is proportional to the DM parameter. Finally, further increasing the magnetic field and for finite $D$ there is a small stiffness regime where the spin current shows, at fixed magnetization, a jump to large values at $D = 0$, a phenomenon also due to the flat band.
Gravitational-wave physics with Cosmic Explorer: limits to low-frequency sensitivity
Creators: name: Hall, Evan D.
name: Kuns, Kevin
name: Smith, Joshua R.
name: Bai, Yuntao
name: Wipf, Christopher
name: Biscans, Sebastien
name: Adhikari, Rana X
name: Arai, Koji
name: Ballmer, Stefan
name: Barsotti, Lisa
name: Chen, Yanbei
name: Evans, Matthew
name: Fritschel, Peter
name: Harms, Jan
name: Kamai, Brittany
name: Rollins, Jameson Graef
name: Shoemaker, David
name: Slagmolen, Bram
name: Weiss, Rainer
name: Yamamoto, Hiro
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Cosmic Explorer (CE) is a next-generation ground-based gravitational-wave observatory concept, envisioned to begin operation in the 2030s, and expected to be capable of observing binary neutron star and black hole mergers back to the time of the first stars. Cosmic Explorer's sensitive band will extend below 10 Hz, where the design is predominantly limited by geophysical, thermal, and quantum noises. In this work, thermal, seismic, gravity-gradient, quantum, residual gas, scattered-light, and servo-control noises are analyzed in order to motivate facility and vacuum system design requirements, potential test mass suspensions, Newtonian noise reduction strategies, improved inertial sensors, and cryogenic control requirements. Our analysis shows that with improved technologies, Cosmic Explorer can deliver a strain sensitivity better than $10^{-23}/\mathrm{Hz}^{1/2}$ down to 5 Hz. Our work refines and extends previous analysis of the Cosmic Explorer concept and outlines the key research areas needed to make this observatory a reality.
description: 24 pages, 19 figures; expanded discussion of residual gas and quantum noises, and updated scattered light estimates
Cosmic (super)string constraints from 21 cm radiation
Creators: name: Khatri, Rishi
name: Wandelt, Benjamin D.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We calculate the contribution of cosmic strings arising from a phase transition in the early universe, or cosmic superstrings arising from brane inflation, to the cosmic 21 cm power spectrum at redshifts z > 30. Future experiments can exploit this effect to constrain the cosmic string tension Gu and probe virtually the entire brane inflation model space allowed by current observations. Although current experiments with a collecting area of ~ 1 km^2 will not provide any useful constraints, future experiments with a collecting area of 10^4-10^6 km^2 covering the cleanest 10% of the sky can in principle constrain cosmic strings with tension Gu > 10^(-10) to 10^(-12) (superstring/phase transition mass scale >10^13 GeV).
description: Accepted for publication in PRL
Weibel Filament Decay and Thermalization in Collisionless Shocks and Gamma-Ray Burst Afterglows
Creators: name: Milosavljevic, Milos
name: Nakar, Ehud
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Models for the synchrotron emission of gamma-ray burst afterglows suggest that the magnetic field is generated in the shock wave that forms as relativistic ejecta plow through the circum-burst medium. Transverse Weibel instability efficiently generates magnetic fields near equipartition with the post-shock energy density. The detailed saturated state of the instability, as seen in particle-in-cell simulations, consists of magnetically self-pinched current filaments. The filaments are parallel to the direction of propagation of the shock and are about a plasma skin depth in radius, forming a quasi--two-dimensional structure. We use a rudimentary analytical model to argue that the Weibel filaments are unstable to a kink-like mode, which destroys their quasi--two-dimensional structure. For wavelengths longer than than the skin depth, the instability grows at the rate equal to the speed of light divided by the wavelength. We calculate the transport of collisionless test particles in the filaments experiencing the instability and show that the particles diffuse in energy. This diffusion marks the beginning of thermalization in the shock transition layer, and causes initial magnetic field decay as particles escape from the filaments. We discuss the implications of these results for the structure of the shock and the polarization of the afterglow.
description: 6 pages, 1 figure
Generating random quantum channels
Creators: name: Kukulski, Ryszard
name: Nechita, Ion
name: Pawela, Łukasz
name: Puchała, Zbigniew
name: Życzkowski, Karol
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Several techniques of generating random quantum channels, which act on the set of $d$-dimensional quantum states, are investigated. We present three approaches to the problem of sampling of quantum channels and show under which conditions they become mathematically equivalent, and lead to the uniform, Lebesgue measure on the convex set of quantum operations. We compare their advantages and computational complexity and demonstrate which of them is particularly suitable for numerical investigations. Additional results focus on the spectral gap and other spectral properties of random quantum channels and their invariant states. We compute mean values of several quantities characterizing a given quantum channel, including its unitarity, the average output purity and the $2$-norm coherence of a channel, averaged over the entire set of the quantum channels with respect to the uniform measure. An ensemble of classical stochastic matrices obtained due to super-decoherence of random quantum stochastic maps is analyzed and their spectral properties are studied using the Bloch representation of a classical probability vector.
description: 29 pages, 7 figures
Study of $Zγ$ events and limits on anomalous $ZZγ$ and $Zγγ$ couplings in ppbar collisions at $sqrt(s) = 1.96$ TeV
Creators: name: D0 Collaboration
name: Abazov, V. M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We present a measurement of the Zγproduction cross section and limits on anomalous ZZγand Zγγcouplings for form-factor scales of Lambda = 750 and 1000 GeV. The measurement is based on 138 (152) candidate events in the eeγ(μμγ) final state using 320 (290) pb^{-1} of ppbar collisions at \sqrt{s} = 1.96 TeV. The 95% C.L. limits on real and imaginary parts of individual anomalous couplings are |h_{10,30}^{Z}|<0.23, |h_{20,40}^{Z}|<0.020, |h_{10,30}^γ|<0.23, and |h_{20,40}^γ|<0.019 for Lambda = 1000 GeV.
description: submitted to Phys. Rev. Letters
Stochastic maize production technology and production risk analysis in Dadar district, East Ethiopia
Creators: name: Fufa, B.
name: Hassan, Rashid M.
name: Fufa, B.
name: Hassan, Rashid M.
Publisher: name: Unknown
Year: 2003
Subjects: Crop Production/Industries

description: A stochastic production technology that allows risk effects of factor inputs was estimated for maize farmers in Ethiopia. The results suggested that the promoted improved maize technology exhibits constant returns to scale whereas non-adopters use decreasing returns to scale technology. The study showed that timely planting is critical for maize yield stability among both adopters and non-adopters and suggests the importance of using oxen and higher efforts to achieve that. Nevertheless, the results showed that most of the factors under the control of the farmers do not offer powerful explanation to maize yield variability compared to natural factors such as rainfall, frost, pests and diseases.
Patterns of access to rural service infrastructure: the case of farming households in Limpopo Province
Creators: name: Makhura, Moraka Nakedi
name: Wasike, W.S.K.
name: Makhura, Moraka Nakedi
name: Wasike, W.S.K.
Publisher: name: Unknown
Year: 2003
Subjects: Community/Rural/Urban Development

description: Inadequate infrastructure is a major development challenges in developing countries. This paper applies factor analysis to determine the pattern of access to rural service infrastructure on 158 farming households in the Limpopo Province. The nine components of access to service infrastructure (distance to Polokwane, nearest town, local government, hospital, magistrate office, post office, traditional authority, district agricultural offices and extension service) were subjected to factor analysis. The results support the concept of centre-periphery pattern of service infrastructure development. Polokwane is a major centre in the Province, and provide a composite of services. Its peripheries are regions, which have towns as centres. Health, local government and postal services are mainly found in such regional centres. The district centres provide mainly agricultural and justice services. Finally, local centres provide services of traditional authorities, agriculture and postal services. These patterns have major implication for infrastructure development policy and programs. They also need to be considered in current crafting of institutions for rural economic development.