125 research outputs found

    Why discrepancies in searching the conservation biology literature matter

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    Conservation biologists seek as much information as possible for evidence-based conservation actions, so they have a special concern for variations in literature retrieval. We assessed the significance for biological conservation of differences in literature retrieval across databases by comparing five simple subject searches in Scopus, Web of Science (WoS) (comparing two different subscriptions), Web of Science (Core Collection) (WosCC) (comparing two different subscriptions) and Google Scholar (GS). The efficiency of a search (the number of references retrieved by a database as a percentage of the total number retrieved across all databases) ranged from 5% to 92%. Different subscriptions to WoS and WoSCC returned different numbers of references. Additionally, we asked 114 conservation biologists which databases they used, their awareness of differing search options within databases and their awareness of different subscription options. The four most widely used databases were GS (88%), WoS (59%), WoSCC (58%) and Scopus (27%). Most respondents (≥ 65%) were unsure about specific features in databases, although 66% knew of the service GS Citations, and 76% agreed that GS retrieved grey literature effectively. Respondents' publication history did not influence their responses. Researchers seeking comprehensive literature reviews should consult multiple databases, with online searches using GS important for locating books, book chapters and grey literature. Comparative evaluations of publication outputs of researchers or departments are susceptible to variations in content between databases and different subscriptions of the same database, so researchers should justify the databases used and, if applicable, the subscriptions. Students value convenience over thoroughness in literature searches, so relevant education is needed

    Disordered Hubbard Model with Attraction: Coupling Energy of Cooper Pairs in Small Clusters

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    We generalize the Cooper problem to the case of many interacting particles in the vicinity of the Fermi level in the presence of disorder. On the basis of this approach we study numerically the variation of the pair coupling energy in small clusters as a function of disorder. We show that the Cooper pair energy is strongly enhanced by disorder, which at the same time leads to the localization of pairs.Comment: revtex, 5 pages, 6 figure

    Charge symmetry breaking via rho-omega mixing from model quark-gluon dynamics

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    The quark-loop contribution to the ρ0ω\rho^0-\omega mixing self-energy function is calculated using a phenomenologically successful QCD-based model field theory in which the ρ0\rho^0 and ω\omega mesons are composite qˉq\bar{q}q bound states. In this calculation the dressed quark propagator, obtained from a model Dyson-Schwinger equation, is confining. In contrast to previous studies, the meson-qˉq\bar{q}q vertex functions are characterised by a strength and range determined by the dynamics of the model; and the calculated off-mass-shell behaviour of the mixing amplitude includes the contribution from the calculated diagonal meson self-energies. The mixing amplitude is shown to be very sensitive to the small isovector component of dynamical chiral symmetry breaking. The spacelike quark-loop mixing-amplitude generates an insignificant charge symmetry breaking nuclear force.Comment: 11 Pages, 3 figures uuencoded and appended to this file, REVTEX 3.0. ANL-PHY-7718-TH-94, KSUCNR-004-94. [!! PostScript file format corrected. Retrieve by anonymous ftp from theory.phy.anl.gov (130.202.20.190), directory pub: mget wpfig*.ps Three files.

    On the existence of a Bose Metal at T=0

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    This paper aims to justify, at a microscopic level, the existence of a two-dimensional Bose metal, i.e. a metallic phase made out of Cooper pairs at T=0. To this end, we consider the physics of quantum phase fluctuations in (granular) superconductors in the absence of disorder and emphasise the role of two order parameters in the problem, viz. phase order and charge order. We focus on the 2-d Bose Hubbard model in the limit of very large fillings, i.e. a 2-d array of Josephson junctions. We find that the algebra of phase fluctuations is that of the Euclidean group E2E_{2} in this limit, and show that the model is equivalent to two coupled XY models in (2+1)-d, one corresponding to the phase degrees of freedom, and the other the charge degrees of freedom. The Bose metal, then, is the phase in which both these degrees of freedom are disordered(as a result of quantum frustration). We analyse the model in terms of its topological excitations and suggest that there is a strong indication that this state represents a surface of critical points, akin to the gapless spin liquid states. We find a remarkable consistency of this scenario with certain low-T_c thin film experiments.Comment: 16 pages, 2 figure

    Alterations to nuclear architecture and genome behavior in senescent cells.

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    The organization of the genome within interphase nuclei, and how it interacts with nuclear structures is important for the regulation of nuclear functions. Many of the studies researching the importance of genome organization and nuclear structure are performed in young, proliferating, and often transformed cells. These studies do not reveal anything about the nucleus or genome in nonproliferating cells, which may be relevant for the regulation of both proliferation and replicative senescence. Here, we provide an overview of what is known about the genome and nuclear structure in senescent cells. We review the evidence that nuclear structures, such as the nuclear lamina, nucleoli, the nuclear matrix, nuclear bodies (such as promyelocytic leukemia bodies), and nuclear morphology all become altered within growth-arrested or senescent cells. Specific alterations to the genome in senescent cells, as compared to young proliferating cells, are described, including aneuploidy, chromatin modifications, chromosome positioning, relocation of heterochromatin, and changes to telomeres

    Dense Stellar Populations: Initial Conditions

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    This chapter is based on four lectures given at the Cambridge N-body school "Cambody". The material covered includes the IMF, the 6D structure of dense clusters, residual gas expulsion and the initial binary population. It is aimed at those needing to initialise stellar populations for a variety of purposes (N-body experiments, stellar population synthesis).Comment: 85 pages. To appear in The Cambridge N-body Lectures, Sverre Aarseth, Christopher Tout, Rosemary Mardling (eds), Lecture Notes in Physics Series, Springer Verla

    Comparative Advertising Wars: An Historical Analysis of Their Causes and Consequences

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    This historical study contributes to the extensive literature on comparative advertising by examining the causes and consequences of comparative advertising wars; that is, when one advertiser responds to a direct or implied attack by another advertiser. Primary and secondary sources consist of articles published in historic and contemporary marketing and advertising trade journals, such as Printers’ Ink, Advertising & Selling, and Advertising Age. The findings reveal that well-publicized advertising wars occurred frequently between major U.S. advertisers throughout the twentieth century and into the twenty-first, and that they most often occurred in product and service markets characterized by intense competition. Many, if not most, advertisers’ principal motive for responding to a comparative advertising attack has been emotional rather than rational. The findings also reveal that advertising wars often became increasingly hostile, leading to negative consequences for all combatants, as well as a broad and negative social consequence in the form of potentially misleading advertising.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
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