539 research outputs found

    Effects of supplemental food on the habitat selected by Mastomys natalensis (Muridae: Rodentia) in a subtropical grassland in Swaziland

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    Mastomys natalensis, the multimammate mouse, was live-trapped on six grids varying in vegetative cover and vegetation height between June 1996 and May 1997. There were three treatments, each with two replicates: reduced cover, reduced cover with supplementary food and control. The numbers of M. natalensis on the grids with reduced cover were lower than those on the control. Food supplementation, however, significantly increased numbers on one of the replicates. There were also significant differences in the number and proportion of resident and adult mice among the grids. The grids with reduced cover supported a population with a lower number and proportion of adult and resident mice than those on the control. In contrast, despite the reduced cover on the food supplemented grids, the population on one of the these grids exhibited a higher number and proportion of adult and resident mice than those on the control. Mastomys natalensis appears to select patches with greater vegetative cover but it will abandon cover in the presence of an abundant food source

    The digestive tract of Macroscelides proboscideus and the effects of diet quality on gut dimensions

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    The digestive anatomy of the round-eared elephant shrew, Macroscelides proboscideus, was investigated. The gut combines features indicative of both insectivory and herbivory. The stomach is a unilocular glandular sac. The caecum is an elongate blind-ending pouch, and houses a diverse microflora. The colon is well developed (25% of gut length). Digestive anatomy supports Kerley's (1995) contention that M. proboscideus is a true omnivore. The gut dimensions of M. proboscideus responded to differences in food quality, animals fed a high fibre diet exhibiting greater caecal capacity than those fed a low fibre diet. This hindgut plasticity is likely to compensate for short-term changes in food quality

    Diet of serval Felis serval in a highland region of Natal

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    Serval Felis serval diet was determined using faecal analysis. A combination of quantification techniques best illustrated the relative importance of various prey species. Small mammals (Rodentia and Insectívora) accounted for 94% of prey item occurrences. Otomys irroratus was the most important prey species in terms of biomass and number. There was no evidence for servals eating lambs or other medium-sized mammals in the study area

    Group sizes of oribis in different habitats

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    Data collected on group sizes of the oribi Ourebia ourebi at midland elevations in Natal, South Africa, were compared with available data from montane (Drakensberg) and tropical (East Africa) grasslands. Mean group sizes were lowest in montane grassland and highest in tropical grassland. In the montane areas adults occurred mainly in pairs or as single animals, whereas small harem herds predominated in tropical grassland, while the organization at midland areas was intermediate. It is suggested that the social organization of the oribi is influenced by habitat suitability, and availability and quality of food during winter. This hypothesis is discussed in relation to the three areas considered

    Book Reviews

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    Book Review 1Book Title: Pheromones of Social BeesBook Author: John B. FreeChapman & Hall, 1987. 218 pp.Book Review 2Book Title: Insects - PlantsBook Authors: V. Labeyrie et alDr. W. Junk Publishers, The Hague, 1987. 459 pp.Book Review 3Book Title: The Ecology of Woodland Rodents: Bank voles and wood miceBook Authors: Edited by J.R. Flowerdew, J. Gurnell & J.H.W GippsThe Zoological Society of London. Clarendon Press, Oxford, 1985. 418 pp.Book Review 4Book Title: Visual behavior in salamandersBook Author: Gerhard RothSpringer-Verlag, Berlin, 1987. 301 pp.Book Review 5Book Title: Digestive Physiology and Nutrition of MarsupialsBook Author: Ian D. HumeMonographs on Marsupial Biology. Cambridge University Press, 1982. 256 pp.Book Review 6Book Title: Neurobiology and Behavior of HoneybeesBook Authors: Edited by Randolf Menzel & Alison MercerSpringer-Verlag, 1987.334 pp.Book Review 7Book Title: Ecology and Productivity of an African Wetland SystemBook Author: G.A. EllenbroekDr W. Junk Publishers, Dordrecht, 1987. 267 pagesBook Review 8Book Title: Biological Surveys of Estuaries and Coasts Estuarine and Brackish Water Sciences Association HandbookBook Authors: Edited by J.M. Baker & W.J. WolffCambridge University Press, 1987. 449 pp.Book Review 9Book Title: Caste Differentiation in Social InsectsBook Authors: Edited by J.A.L. Watson, S.M. Okot-Kotber & C.H. NoirotPergamon Press, Oxford, 1985. 399 pp.Book Review 10Book Title: Sistematica, filogenia y biogeografia de la subfamilia Gibbiinae (Coleoptera, Ptinidae)Book Author: Xavier BellésTreballs del Museu de Zoologia, 1985, No.3, Barcelona. 94 pp.Book Review 11Book Title: A Biologist's Advanced MathematicsBook Author: D.R. CaustonAllen & Unwin, London 326 pp.Book Review 12 Book Title: Reproduction in Mammals: 5 Manipulating reproductionBook Authors: Edited by C.R. Austin & R.V. ShortCambridge University Press, London, New York, New Rochelle, Melbourne, Sydney. 235 pp.Book Review 13Book Title: Vertebrate Fetal MembranesBook Author: Harland W. MossmanMacmillan press, 1987. 383 pp.Book Review 14Book Title: Avian Physiology (Fourth edition)Book Author: Edited by P.O. SturkieSpringer-Verlag, New York, 1986. 516 pp

    Book Reviews

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    Book Review 1Book Title: Early Life Histories of Fishes: New Developmental, Ecological and Evolutionary PerspectivesBook Author: Edited by E.K. BalonDr W. Junk, Dordrecht. 280 pp.Book Review 2Book Title: Comparative Aspects of Extracellular Acid-base BalanceBook Author: J.P. TruchotSpringer, 1987. 248 pp. 51 figures.Book Review 3Book Title: Insect Flight: Dispersal and MigrationBook Author: Edited by W. DanthanarayanaSpringer-Verlag, Berlin, 1986. 289 pp.Book Review 4Book Title:  The Mammalian Herbivore Stomach. Comparative Anatomy, Function and EvolutionBook Author: Peter LangerGustav Fischer, Stuttgart, 1988. 557 pages, 246 figures and 72 tablesBook Review 5Book Title:  Biology of the Integument. Vol. 2: VertebratesBook Authors: Edited by J. Bereiter-Hahn, A.G. Matoltsy & K.S. RichardsSpringer, Berlin, 1986. 855 pp.Book Review 6Book Title:  Advances in the Biology of Turbellarians and related PlatyhelminthesBook Author: Edited by Seth TylerDr. W. Junk Publishers, 1986. 357 pages; 253 figuresBook Review 7Book Title: Evolutionary Physiological EcologyBook Author: Edited by P. CalowCambridge University Press, Cambridge. 239 pp.Book Review 8Book Title: DragonfliesBook Author: Peter L. MillerCambridge University Press, Cambridge, New York and Melbourne, 1987. 84 pp

    Density correlations and dynamical Casimir emission of Bogoliubov phonons in modulated atomic Bose-Einstein condensates

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    We present a theory of the density correlations that appear in an atomic Bose-Einstein condensate as a consequence of the dynamical Casimir emission of pairs of Bogoliubov phonons when the atom-atom scattering length is modulated in time. Different regimes as a function of the temporal shape of the modulation are identified and a simple physical picture of the phenomenon is discussed. Analytical expressions for the density correlation function are provided for the most significant limiting cases. This theory is able to explain some unexpected features recently observed in numerical calculations of Hawking radiation from analog black holes

    Genetic effects on liver chromatin accessibility identify disease regulatory variants

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    Identifying the molecular mechanisms by which genome-wide association study (GWAS) loci influence traits remains challenging. Chromatin accessibility quantitative trait loci (caQTLs) help identify GWAS loci that may alter GWAS traits by modulating chromatin structure, but caQTLs have been identified in a limited set of human tissues. Here we mapped caQTLs in human liver tissue in 20 liver samples and identified 3,123 caQTLs. The caQTL variants are enriched in liver tissue promoter and enhancer states and frequently disrupt binding motifs of transcription factors expressed in liver. We predicted target genes for 861 caQTL peaks using proximity, chromatin interactions, correlation with promoter accessibility or gene expression, and colocalization with expression QTLs. Using GWAS signals for 19 liver function and/or cardiometabolic traits, we identified 110 colocalized caQTLs and GWAS signals, 56 of which contained a predicted caPeak target gene. At the LITAF LDL-cholesterol GWAS locus, we validated that a caQTL variant showed allelic differences in protein binding and transcriptional activity. These caQTLs contribute to the epigenomic characterization of human liver and help identify molecular mechanisms and genes at GWAS loci

    Partial wave analysis of the reaction gamma p -> p omega$ and the search for nucleon resonances

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    An event-based partial wave analysis (PWA) of the reaction gamma p -> p omega has been performed on a high-statistics dataset obtained using the CLAS at Jefferson Lab for center-of-mass energies from threshold up to 2.4 GeV. This analysis benefits from access to the world's first high precision spin density matrix element measurements, available to the event-based PWA through the decay distribution of omega-> pi+ pi - pi0. The data confirm the dominance of the t-channel pi0 exchange amplitude in the forward direction. The dominant resonance contributions are consistent with the previously identified states F[15](1680) and D[13](1700) near threshold, as well as the G[17](2190) at higher energies. Suggestive evidence for the presence of a J(P)=5/2(+) state around 2 GeV, a "missing" state, has also been found. Evidence for other states is inconclusive

    Multiplicity dependence of inclusive J/psi production at midrapidity in pp collisions at root s=13 TeV

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    Measurements of the inclusive J/psi yield as a function of charged-particle pseudorapidity density dN(ch)/d eta in pp collisions at root s = 13 TeV with ALICE at the LHC are reported. The J/psi meson yield is measured at midrapidity (vertical bar y vertical bar <0.9) in the dielectron channel, for events selected based on the charged-particle multiplicity at midrapidity (vertical bar eta vertical bar <1) and at forward rapidity (-3.7 <eta <-1.7 and 2.8 <eta <5.1); both observables are normalized to their corresponding averages in minimum bias events. The increase of the normalized J/psi yield with normalized dN(ch)/d eta is significantly stronger than linear and dependent on the transverse momentum. The data are compared to theoretical predictions, which describe the observed trends well, albeit not always quantitatively. (C) 2020 European Organization for Nuclear Research. Published by Elsevier B.V.Peer reviewe
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