376 research outputs found

    The identity of Chelodina oblonga Gray 1841 (Testudines Chelidae) reassessed

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    FIGURE 2. Illustration of Chelodina oblonga by Gray (1841), based on BMNH 1947.3.5.89. Compare with photographs of the same specimen in Figure 1.Published as part of Shea, Glenn, Thomson, Scott & Georges, Arthur, 2020, The identity of Chelodina oblonga Gray 1841 (Testudines: Chelidae) reassessed, pp. 419-437 in Zootaxa 4779 (3) on page 423, DOI: 10.11646/zootaxa.4779.3.9, http://zenodo.org/record/397482

    Developing a faculty learning community grounded in the science of how people learn: A Year-Long, Faculty-Led Teaching and Learning Seminar.

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    This chapter describes a multiyear professional development effort undertaken by a learning and teaching center at a liberal arts college. As part of its founding mandate, the center helps faculty improve teaching by paying attention to the current literature about how people learn. This core commitment of our center is pursued through support of a year‐long faculty seminar. Now in its fourth year, the seminar has had a significant impact on its faculty participants and their thinking about teaching and learning. Moreover, the seminar has seeded a number of teaching and assessment initiatives at the college

    A Delphi Consensus to Identify Perioperative Antibiotic Prescribing Best Practices in Mohs Surgery

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    Abstract: Surgical site infections (SSI) make a significant global contribution to morbidity, mortality, and cost while remaining one of the most preventable causes of healthcare-associated infection. Perioperative antibiotics are a mainstay of prevention, but antibiotics are also associated with cost, risk, and increasing resistance. Dermatology is responsible for more oral antibiotic prescriptions than any other discipline. Despite a trend toward conservative prescribing practices and antibiotic stewardship in dermatology overall, antibiotic prescriptions in dermatologic surgery continue to increase, with a notable rise in short-term perioperative prescribing. There is currently a lack of evidence-based perioperative antibiotic prescribing guidelines within the dermatology literature. Evidence supports the need for specific, up-to-date recommendations regarding antibiotic management in the setting of dermatologic surgery. This QI project aims to review and synthesize current recommendations in the literature and identify best practices for developing standardized, appropriate use criteria for perioperative use of antibiotics in dermatologic surgery

    SOX17 Regulates Conversion of Human Fibroblasts Into Endothelial Cells and Erythroblasts by Dedifferentiation Into CD34+ Progenitor Cells

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    BACKGROUND: The mechanisms underlying the dedifferentiation and lineage conversion of adult human fibroblasts into functional endothelial cells have not yet been fully defined. Furthermore, it is not known whether fibroblast dedifferentiation recapitulates the generation of multipotent progenitors during embryonic development, which give rise to endothelial and hematopoietic cell lineages. Here we established the role of the developmental transcription factor SOX17 in regulating the bilineage conversion of fibroblasts by the generation of intermediate progenitors. METHODS: CD34+ progenitors were generated after the dedifferentiation of human adult dermal fibroblasts by overexpression of pluripotency transcription factors. Sorted CD34+ cells were transdifferentiated into induced endothelial cells and induced erythroblasts using lineage-specific growth factors. The therapeutic potential of the generated cells was assessed in an experimental model of myocardial infarction. RESULTS: Induced endothelial cells expressed specific endothelial cell surface markers and also exhibited the capacity for cell proliferation and neovascularization. Induced erythroblasts expressed erythroid surface markers and formed erythroid colonies. Endothelial lineage conversion was dependent on the upregulation of the developmental transcription factor SOX17, whereas suppression of SOX17 instead directed the cells toward an erythroid fate. Implantation of these human bipotential CD34+ progenitors into nonobese diabetic/severe combined immunodeficiency (NOD-SCID) mice resulted in the formation of microvessels derived from human fibroblasts perfused with mouse and human erythrocytes. Endothelial cells generated from human fibroblasts also showed upregulation of telomerase. Cell implantation markedly improved vascularity and cardiac function after myocardial infarction without any evidence of teratoma formation. CONCLUSIONS: Dedifferentiation of fibroblasts to intermediate CD34+ progenitors gives rise to endothelial cells and erythroblasts in a SOX17-dependent manner. These findings identify the intermediate CD34+ progenitor state as a critical bifurcation point, which can be tuned to generate functional blood vessels or erythrocytes and salvage ischemic tissue

    Dehydration entropy drives liquid-liquid phase separation by molecular crowding

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    Liquid-liquid phase separation occurs in cells and can be induced in artificial systems, but the mechanism of the effect of molecular crowders is unclear. Here dehydration entropy-driven phase separation of model charged polymers lacking any chemical complexity or hydrophobicity is shown to be enhanced by polyethylene glycol. Complex coacervation driven liquid-liquid phase separation (LLPS) of biopolymers has been attracting attention as a novel phase in living cells. Studies of LLPS in this context are typically of proteins harboring chemical and structural complexity, leaving unclear which properties are fundamental to complex coacervation versus protein-specific. This study focuses on the role of polyethylene glycol (PEG)-a widely used molecular crowder-in LLPS. Significantly, entropy-driven LLPS is recapitulated with charged polymers lacking hydrophobicity and sequence complexity, and its propensity dramatically enhanced by PEG. Experimental and field-theoretic simulation results are consistent with PEG driving LLPS by dehydration of polymers, and show that PEG exerts its effect without partitioning into the dense coacervate phase. It is then up to biology to impose additional variations of functional significance to the LLPS of biological systems.11Ysciescopu

    A New Small-Bodied Species of Bavayia (Reptilia: Squamata: Diplodactylidae) from Southeastern New Caledonia.

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    v. ill. 23 cm.QuarterlyA new species of diplodactylid genus Bavayia, B. goroensis, is described from the Plaine des Lacs region of the Province Sud, New Caledonia. The new gecko is the smallest member of the Bavayia cyclura clade (49 mm snout-vent length) and, based on a molecular phylogeny, is basal within this group. It differs from other members of this group in its much smaller size, more gracile body, and lower number of precloacal pores and subdigital lamellae. The new species is known from only two locations, one of which is adjacent to extensive nickel mining operations. Because of its limited distribution and the direct and indirect threats posed by the proximity of mining to one of the populations, the species is here regarded as ‘‘Endangered.’

    Speciation in the mountains and dispersal by rivers: Molecular phylogeny of Eulamprus water skinks and the biogeography of Eastern Australia

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    Aim: To develop a robust phylogeny for the iconic Australian water skinks (Eulamprus) and to explore the influence of landscape evolution of eastern Australia on phylogeographic patterns. Location: Eastern and south-eastern Australia. Methods: We used Sanger methods to sequence a mitochondrial DNA (mtDNA) locus for 386 individuals across the five Eulamprus species to elucidate phylogeographic structure. We also sequenced a second mtDNA locus and four nuclear DNA (nDNA) loci for a subset of individuals to help inform our sampling strategy for next-generation sequencing. Finally, we generated an anchored hybrid enrichment (AHE) approach to sequence 378 loci for 25 individuals representing the major lineages identified in our Sanger dataset. These data were used to resolve the phylogenetic relationships among the species using coalescent-based species tree inference in *BEAST and ASTRAL. Results: The relationships between Eulamprus species were resolved with a high level of confidence using our AHE dataset. In addition, our extensive mtDNA sampling revealed substantial phylogeographic structure in all species, with the exception of the geographically highly restricted E. leuraensis. Ratios of patristic distances (mtDNA/nDNA) indicate on average a 30-fold greater distance as estimated using the mtDNA locus ND4. Main conclusions: The major divergences between lineages strongly support previously identified biogeographic barriers in eastern Australia based on studies of other taxa. These breaks appear to correlate with regions where the Great Escarpment is absent or obscure, suggesting topographic lowlands and the accompanying dry woodlands are a major barrier to dispersal for water skinks. While some river corridors, such as the Hunter Valley, were likely historically dry enough to inhibit the movement of Eulamprus populations, our data indicate that others, such as the Murray and Darling Rivers, are able to facilitate extensive gene flow through the vast arid and semi-arid lowlands of New South Wales and South Australia. Comparing the patristic distances between the mitochondrial and AHE datasets highlights the continued value in analysing both types of data.Australian Research Counci

    Proximity effect at superconducting Sn-Bi2Se3 interface

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    We have investigated the conductance spectra of Sn-Bi2Se3 interface junctions down to 250 mK and in different magnetic fields. A number of conductance anomalies were observed below the superconducting transition temperature of Sn, including a small gap different from that of Sn, and a zero-bias conductance peak growing up at lower temperatures. We discussed the possible origins of the smaller gap and the zero-bias conductance peak. These phenomena support that a proximity-effect-induced chiral superconducting phase is formed at the interface between the superconducting Sn and the strong spin-orbit coupling material Bi2Se3.Comment: 7 pages, 8 figure

    Heavy Quarks and Heavy Quarkonia as Tests of Thermalization

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    We present here a brief summary of new results on heavy quarks and heavy quarkonia from the PHENIX experiment as presented at the "Quark Gluon Plasma Thermalization" Workshop in Vienna, Austria in August 2005, directly following the International Quark Matter Conference in Hungary.Comment: 8 pages, 5 figures, Quark Gluon Plasma Thermalization Workshop (Vienna August 2005) Proceeding

    Production of phi mesons at mid-rapidity in sqrt(s_NN) = 200 GeV Au+Au collisions at RHIC

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    We present the first results of meson production in the K^+K^- decay channel from Au+Au collisions at sqrt(s_NN) = 200 GeV as measured at mid-rapidity by the PHENIX detector at RHIC. Precision resonance centroid and width values are extracted as a function of collision centrality. No significant variation from the PDG accepted values is observed. The transverse mass spectra are fitted with a linear exponential function for which the derived inverse slope parameter is seen to be constant as a function of centrality. These data are also fitted by a hydrodynamic model with the result that the freeze-out temperature and the expansion velocity values are consistent with the values previously derived from fitting single hadron inclusive data. As a function of transverse momentum the collisions scaled peripheral.to.central yield ratio RCP for the is comparable to that of pions rather than that of protons. This result lends support to theoretical models which distinguish between baryons and mesons instead of particle mass for explaining the anomalous proton yield.Comment: 326 authors, 24 pages text, 23 figures, 6 tables, RevTeX 4. To be submitted to Physical Review C as a regular article. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm
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