813 research outputs found

    Population genetic evidence for sex-specific dispersal in an inbred social spider

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    A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author's publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Dispersal in most group-living species ensures gene flow among groups, but in cooperative social spiders, juvenile dispersal is suppressed and colonies are highly inbred. It has been suggested that such inbred sociality is advantageous in the short term, but likely to lead to extinction or reduced speciation rates in the long run. In this situation, very low levels of dispersal and gene flow among colonies may have unusually important impacts on fitness and persistence of social spiders. We investigated sex-specific differences in dispersal and gene flow among colonies, as reflected in the genetic structure within colonies and populations of the African social spider Stegodyphus dumicola Pocock, 1898 (Eresidae). We used DNA fingerprinting and mtDNA sequence data along with spatial mapping of colonies to compare male and female patterns of relatedness within and among colonies at three study sites. Samples were collected during and shortly after the mating season to detect sex-specific dispersal. Distribution of mtDNA haplotypes was consistent with proliferation of social nests by budding and medium- to long-distance dispersal by ballooning females. Analysis of molecular variance and spatial autocorrelation analyses of AFLPs showed high levels of genetic similarity within colonies, and STRUCTURE analyses revealed that the number of source populations contributing to colonies ranged from one to three. We also showed significant evidence of male dispersal among colonies at one site. These results support the hypothesis that in social spiders, genetic cohesion among populations is maintained by long-distance dispersal of female colony founders. Genetic diversity within colonies is maintained by colony initiation by multiple dispersing females, and adult male dispersal over short distances. Male dispersal may be particularly important in maintaining gene flow among colonies in local populations

    A Relational Model for Environmental and Water Resources Data

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    Environmental observations are fundamental to hydrology and water resources, and the way these data are organized and manipulated either enables or inhibits the analyses that can be performed. The Observations Data Model presented here provides a new and consistent format for the storage and retrieval of point environmental observations in a relational database designed to facilitate integrated analysis of large data sets collected by multiple investigators. Within this data model, observations are stored with sufficient ancillary information (metadata) about the observations to allow them to be unambiguously interpreted and to provide traceable heritage from raw measurements to useable information. The design is based upon a relational database model that exposes each single observation as a record, taking advantage of the capability in relational database systems for querying based upon data values and enabling cross‐dimension data retrieval and analysis. This paper presents the design principles and features of the Observations Data Model and illustrates how it can be used to enhance the organization, publication, and analysis of point observations data while retaining a simple relational format. The contribution of the data model to water resources is that it represents a new, systematic way to organize and share data that overcomes many of the syntactic and semantic differences between heterogeneous data sets, thereby facilitating an integrated understanding of water resources based on more extensive and fully specified information

    NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

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    Incluye contenido parcial de los autoresAbstract.Mammalian carnivores are considered a key group in maintaining ecologicalhealth and can indicate potential ecological integrity in landscapes where they occur. Carni-vores also hold high conservation value and their habitat requirements can guide managementand conservation plans. The order Carnivora has 84 species from 8 families in the Neotropicalregion: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; andUrsidae. Herein, we include published and unpublished data on native terrestrial Neotropicalcarnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTRO-PICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data wereobtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organi-zations, and private consultants. Data were collected using several methods including cameratrapping, museum collections, roadkill, line transect, and opportunistic records. Literature(peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated inthis compilation. Most of the data set consists of detection data entries (n=79,343; 79.7%) butalso includes non-detection data (n=20,262; 20.3%). Of those, 43.3% also include count data(n=43,151). The information available in NEOTROPICAL CARNIVORES will contribute tomacroecological, ecological, and conservation questions in multiple spatio-temporal perspec-tives. As carnivores play key roles in trophic interactions, a better understanding of their distri-bution and habitat requirements are essential to establish conservation management plans andsafeguard the future ecological health of Neotropical ecosystems. Our data paper, combinedwith other large-scale data sets, has great potential to clarify species distribution and relatedecological processes within the Neotropics. There are no copyright restrictions and no restric-tion for using data from this data paper, as long as the data paper is cited as the source of theinformation used. We also request that users inform us of how they intend to use the data

    Fossil Carder Bee's nest from the Hominin locality of Taung, South Africa

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    The Buxton-Norlim Limeworks southwest of Taung, South Africa, is renowned for the discovery of the first Australopithecus africanus fossil, the ‘Taung Child’. The hominin was recovered from a distinctive pink calcrete that contains an abundance of invertebrate ichnofauna belonging to the Coprinisphaera ichnofacies. Here we describe the first fossil bee’s nest, attributed to the ichnogenus Celliforma, from the Plio-Pleistocene of Africa. Petrographic examination of a cell lining revealed the preservation of an intricate organic matrix lined with the calcitic casts of numerous plant trichomes–a nesting behaviour unique to the modern-day carder bees (Anthidiini). The presence of Celliforma considered alongside several other recorded ichnofossils can be indicative of a dry, savannah environment, in agreement with recent work on the palaeoenvironment of Plio-Pleistocene southern Africa. Moreover, the occurrence of ground-nesting bees provides further evidence that the pink calcrete deposits are of pedogenic origin, rather than speleogenic origin as has previously been assumed. This study demonstrates the potential value of insect trace fossils as palaeoenvironmental indicators

    Acute gamma-secretase inhibition of nonhuman primate CNS shifts amyloid precursor protein (APP) metabolism from amyloid-beta production to alternative APP fragments without amyloid-beta rebound

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    The accumulation of amyloid beta (Aβ) in Alzheimer’s disease is caused by an imbalance of production and clearance, which leads to increased soluble Aβ species and extracellular plaque formation in the brain. Multiple Aβ-lowering therapies are currently in development: an important goal is to characterize the molecular mechanisms of action and effects on physiological processing of Aβ, as well as other amyloid precursor protein (APP) metabolites, in models which approximate human Aβ physiology. To this end, we report the translation of the human in vivo stable-isotope-labeling kinetics (SILK) method to a rhesus monkey cisterna magna ported (CMP) nonhuman primate model, and use the model to test the mechanisms of action of a γ-secretase inhibitor (GSI). A major concern of inhibiting the enzymes which produce Aβ (β- and γ-secretase) is that precursors of Aβ may accumulate and cause a rapid increase in Aβ production when enzyme inhibition discontinues. In this study, the GSI MK-0752 was administered to conscious CMP rhesus monkeys in conjunction with in vivo stable isotope labeling, and dose-dependently reduced newly generated CNS Aβ. In contrast to systemic Aβ metabolism, CNS Aβ production was not increased after the GSI was cleared. These results indicate that most of the CNS APP was metabolized to products other than Aβ, including C-terminal truncated forms of Aβ: 1–14, 1–15 and 1–16; this demonstrates an alternative degradation pathway for CNS amyloid precursor protein during γ-secretase inhibition

    Drawing Phylogenetic Trees

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    We present linear-time algorithms for drawing phylogenetic trees in radial and circular representations. In radial drawings given edge lengths (representing evolutionary distances) are preserved, but labels (names of taxons represented in the leaves) need to be adjusted, whereas in circular drawings labels are perfectly spread out, but edge lengths adjusted. Our algorithms produce drawings that are unique solutions to reasonable criteria and assign to each subtree a wedge of its own. The linear running time is particularly interesting in the circular case, because our approach is a special case of Tutte s barycentric layout algorithm involving the solution of a system of linear equations

    Some information theoretic optimality criteria for general classification

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43197/1/11004_2005_Article_BF02045962.pd

    The Antiquity and Evolutionary History of Social Behavior in Bees

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    A long-standing controversy in bee social evolution concerns whether highly eusocial behavior has evolved once or twice within the corbiculate Apidae. Corbiculate bees include the highly eusocial honey bees and stingless bees, the primitively eusocial bumble bees, and the predominantly solitary or communal orchid bees. Here we use a model-based approach to reconstruct the evolutionary history of eusociality and date the antiquity of eusocial behavior in apid bees, using a recent molecular phylogeny of the Apidae. We conclude that eusociality evolved once in the common ancestor of the corbiculate Apidae, advanced eusociality evolved independently in the honey and stingless bees, and that eusociality was lost in the orchid bees. Fossil-calibrated divergence time estimates reveal that eusociality first evolved at least 87 Mya (78 to 95 Mya) in the corbiculates, much earlier than in other groups of bees with less complex social behavior. These results provide a robust new evolutionary framework for studies of the organization and genetic basis of social behavior in honey bees and their relatives
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