22 research outputs found

    New material of Coryphomys buehleri Schaub, 1937, and description of a second species of the genus.

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    80 p. : ill. (some col.), maps ; 26 cm. Issued July 21, 2010.Large collections of fragmentary animal bones excavated from archaeological contexts in East Timor between 1968 and 2002 provide new material referable to the recently extinct, gigantic murine genus Coryphomys. We document the upper and lower dentition and palatal anatomy of C. buehleri Schaub, 1937, and identify and name a second species of Coryphomys, based on differences in molar size and morphology and skeletal robusticity. Alternative interpretations of the observed morphological and metric variability (sexual dimorphism, resource-based polymorphism, sample heterochroneity) are each carefully assessed and rejected, and we conclude that the genus comprised two species of approximately similar body size. Preserved cranial elements of both species of Coryphomys feature a high degree of anatomical specialization, including an unusual elaboration of the maxillary sinus complex. Though the specialized anatomy of Coryphomys invites consideration of its phylogenetic relationships, this exercise is hindered by a demonstrable high level of homoplasy (i.e., multiple, independent evolutionary losses and gains) in many of the key craniodental features traditionally surveyed within Murinae, while other features are insufficiently well surveyed for broad-scale analysis. Nevertheless, our comparisons highlight two potentially related lineages among the geographically proximate Murinae - the Philippine Phloeomyini and the Australo-Papuan Hydromyini. The remains of Coryphomys are relatively scarce in all the archaeological samples, but distributional evidence suggests that both species of Coryphomys were found primarily in upland habitats. Late Pleistocene samples document their former presence at lower elevations, possibly reflecting cooler climatic conditions at that time

    Giant bandicoot.

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    41 p. : ill., map ; 26 cm. "September 14, 2010."The giant bandicoot, Peroryctes broadbenti (Ramsay, 1879), is represented in museum collections by 23 specimens collected at 12 localities in the lowlands of the southeastern peninsula (the "Papuan Peninsula") of Papua New Guinea. Available data on P. broadbenti are reviewed, including its comparative anatomy and morphological variability, taxonomic relationships, geographic and elevational distribution, dietary and reproductive traits, and conservation status. Despite previous confusion between this species and P. raffrayana (Milne-Edwards, 1878), the two species are readily distinguished by a suite of external, cranial, and dental characters. Diagnostic characters are enumerated and illustrated, and comparisons drawn with other New Guinean bandicoots. Generic distinction of Peroryctes Thomas, 1906, in cranial morphology from other New Guinean bandicoots is also reviewed. A striking degree of sexual dimorphism is documented in both body size and dentition for P. broadbenti; these comparisons are set in context by a review of sexual dimorphism among bandicoots in general

    Isolation and Characterization of Human Trophoblast Side-Population (SP) Cells in Primary Villous Cytotrophoblasts and HTR-8/SVneo Cell Line

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    Recently, numerous studies have identified that immature cell populations including stem cells and progenitor cells can be found among “side-population” (SP) cells. Although SP cells isolated from some adult tissues have been reported elsewhere, isolation and characterization of human trophoblast SP remained to be reported. In this study, HTR-8/SVneo cells and human primary villous cytotrophoblasts (vCTBs) were stained with Hoechst 33342 and SP and non-SP (NSP) fractions were isolated using a cell sorter. A small population of SP cells was identified in HTR-8/SVneo cells and in vCTBs. SP cells expressed several vCTB-specific markers and failed to express syncytiotrophoblast (STB) or extravillous cytotrophopblast (EVT)-specific differentiation markers. SP cells formed colonies and proliferated on mouse embryonic fibroblast (MEF) feeder cells or in MEF conditioned medium supplemented with heparin/FGF2, and they also showed long-term repopulating property. SP cells could differentiate into both STB and EVT cell lineages and expressed several differentiation markers. Microarray analysis revealed that IL7R and IL1R2 were exclusively expressed in SP cells and not in NSP cells. vCTB cells sorted as positive for both IL7R and IL1R2 failed to express trophoblast differentiation markers and spontaneously differentiated into both STB and EVT in basal medium. These features shown by the SP cells suggested that IL7R and IL1R2 are available as markers to detect the SP cells and that vCTB progenitor cells and trophoblast stem cells were involved in the SP cell population

    Investigation of hospital discharge cases and SARS-CoV-2 introduction into Lothian care homes

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    Background The first epidemic wave of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in Scotland resulted in high case numbers and mortality in care homes. In Lothian, over one-third of care homes reported an outbreak, while there was limited testing of hospital patients discharged to care homes. Aim To investigate patients discharged from hospitals as a source of SARS-CoV-2 introduction into care homes during the first epidemic wave. Methods A clinical review was performed for all patients discharges from hospitals to care homes from 1st March 2020 to 31st May 2020. Episodes were ruled out based on coronavirus disease 2019 (COVID-19) test history, clinical assessment at discharge, whole-genome sequencing (WGS) data and an infectious period of 14 days. Clinical samples were processed for WGS, and consensus genomes generated were used for analysis using Cluster Investigation and Virus Epidemiological Tool software. Patient timelines were obtained using electronic hospital records. Findings In total, 787 patients discharged from hospitals to care homes were identified. Of these, 776 (99%) were ruled out for subsequent introduction of SARS-CoV-2 into care homes. However, for 10 episodes, the results were inconclusive as there was low genomic diversity in consensus genomes or no sequencing data were available. Only one discharge episode had a genomic, time and location link to positive cases during hospital admission, leading to 10 positive cases in their care home. Conclusion The majority of patients discharged from hospitals were ruled out for introduction of SARS-CoV-2 into care homes, highlighting the importance of screening all new admissions when faced with a novel emerging virus and no available vaccine

    SARS-CoV-2 Omicron is an immune escape variant with an altered cell entry pathway

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    Vaccines based on the spike protein of SARS-CoV-2 are a cornerstone of the public health response to COVID-19. The emergence of hypermutated, increasingly transmissible variants of concern (VOCs) threaten this strategy. Omicron (B.1.1.529), the fifth VOC to be described, harbours multiple amino acid mutations in spike, half of which lie within the receptor-binding domain. Here we demonstrate substantial evasion of neutralization by Omicron BA.1 and BA.2 variants in vitro using sera from individuals vaccinated with ChAdOx1, BNT162b2 and mRNA-1273. These data were mirrored by a substantial reduction in real-world vaccine effectiveness that was partially restored by booster vaccination. The Omicron variants BA.1 and BA.2 did not induce cell syncytia in vitro and favoured a TMPRSS2-independent endosomal entry pathway, these phenotypes mapping to distinct regions of the spike protein. Impaired cell fusion was determined by the receptor-binding domain, while endosomal entry mapped to the S2 domain. Such marked changes in antigenicity and replicative biology may underlie the rapid global spread and altered pathogenicity of the Omicron variant

    A review of Microhydromys (Rodentia, Murinae), with description of a new species from southern New Guinea. (American Museum novitates, no. 3676)

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    22 p. : ill. (some col.), map ; 26 cm. "March 4, 2010." Includes bibliographical references (p. 19-22).The murine rodent genus Microhydromys Tate and Archbold, 1941, includes the smallest of the native rodents of New Guinea and is the rarest Australo-Papuan rodent genus preserved in world museums. We discuss the morphological characteristics of Microhydromys and diagnose two species in the genus: M. richardsoni Tate and Archbold, 1941, distributed over northern New Guinea, and M. argenteus, n. sp., recorded from three localities in southern New Guinea. The only other species previously classified in the genus--Microhydromys musseri Flannery, 1989--is re-allocated to the genus Pseudohydromys Rümmler, 1934. The little available information relating to their biology indicates the species of Microhydromys to be terrestrial inhabitants of foothill and lower montane forest formations and probably naturally rare in those environments
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