565 research outputs found

    The h-index in Australian Astronomy

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    The Hirsch (2005) h-index is now widely used as a metric to compare individual researchers. To evaluate it in the context of Australian Astronomy, the h-index for every member of the Astronomical Society of Australia (ASA) is found using NASA's Astrophysics Data System Bibliographic Services (ADS). Percentiles of the h-index distribution are detailed for a variety of categories of ASA members, including students. This enables a list of the top ten Australian researchers by h-index to be produced. These top researchers have h-index values in the range 53<h<77, which is less than that recently reported for the American Astronomical Society Membership. We suggest that membership of extremely large consortia such as SDSS may partially explain the difference. We further suggest that many student ASA members with large h-index values have probably already received their Ph.D.'s and need to upgrade their ASA membership status. To attempt to specify the h-index distribution relative to opportunity, we also detail the percentiles of its distribution by years since Ph.D. award date. This shows a steady increase in h-index with seniority, as can be expected.Comment: Accepted for publication in the Publications of the Astronomical Society of Australi

    Differing preferences of Antarctic soil nematodes for microbial prey

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    We tested the preferences of three nematode taxa, Geomonhystera villosa, Plectus spp. and Teratocephalus spp., extracted from moss at Signy Island in the Maritime Antarctic, for two microalgae, three microfungi and six heterotrophic bacteria, each also from soils at Signy Island. Choice test experiments on water agar medium, in which nematodes were enumerated in wells containing microbes at 24 and 48 h, indicated that there were differing preferences between nematodes for distinct prey. G. villosa was significantly attracted to the alga Chlorella cf. minutissima and the fungus Mortierella hyalina, and was more attracted to all algae and fungi than either of the other two nematodes. Both G. villosa and Teratocephalus spp. were attracted to an actinobacterium. Plectus spp. were significantly attracted to the alga Stichococcus bacillaris and bacteria with close taxonomic affinities to Arthrobacter, Pseudomonas and Polaromonas. Experiments using 0.5 μm diameter fluorescent beads indicated significantly increased ingestion by nematodes in the presence of each of these microbes compared with controls, except by Plectus spp. in the presence of S. bacillaris. We conclude that complex trophic interactions may occur in apparently simple Antarctic soil food webs

    A Renormalisation group for TCSA

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    We discuss the errors introduced by level truncation in the study of boundary renormalisation group flows by the Truncated Conformal Space Approach. We show that the TCSA results can have the qualitative form of a sequence of RG flows between different conformal boundary conditions. In the case of a perturbation by the field phi(13), we propose a renormalisation group equation for the coupling constant which predicts a fixed point at a finite value of the TCSA coupling constant and we compare the predictions with data obtained using TBA equations.Comment: 11 pages, 7 figures, talk presented by G Watts at the workshop "Integrable Models and Applications: from Strings to Condensed Matter", Santiago de Compostela, Spain, 12-16 September 200

    Kentucky’s Primary Care Workforce: Current Status and Output of New Trainees January 2020 Update

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    Primary care is the backbone of American healthcare. Primary care (PC) physicians are especially cost-effective in preventing and managing illness and disability, and prolonging years of quality life. They also contribute significantly to the economy of their communities. Primary care shortages across the Commonwealth are severe. Kentucky ranks 43rd in the USA for its number of PC physicians per 100,000 people. The Commonwealth would have to add 246 primary care physicians annually to reach the US median by the end of 2029. Kentucky produces and retains only about 55 new PC physicians per year, recruiting 55 to 60 more from out of state. This total of 110 – 115 new physicians falls short of the 124 PC physicians that must be added annually to avoid worsening our shortage, and far below the 246 PC physicians that Kentucky would need to add each year to reach the US median in the coming decade

    Kentucky’s Primary Care Workforce Shortages 2016 - 2025 and Recommendations for Increasing the Production of Primary Care Physicians for Kentucky

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    An excerpt from the executive summary: Kentucky and the nation face severe shortages of primary care (PC) physicians. PC physicians are essential to cost-effective healthcare. Kentucky ranks 40th among the United States in its PC physician workforce per 100,000 people, with 2,696 practicing PC physicians statewide. The purposes of this white paper are to: Present up-to-date data and information about the primary care workforce in Kentucky Describe current trainee pipelines that supply new primary care physicians to Kentucky Recommend strategies and tactics for improving the primary care physician workforc

    Meteorites and the RNA World: Synthesis of Nucleobases in Carbonaceous Planetesimals and the Role of Initial Volatile Content

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    Prebiotic molecules, fundamental building blocks for the origin of life, have been found in carbonaceous chondrites. The exogenous delivery of these organic molecules onto the Hadean Earth could have sparked the polymerization of the first RNA molecules in Darwinian ponds during wet-dry cycles. Here, we investigate the formation of the RNA and DNA nucleobases adenine, uracil, cytosine, guanine, and thymine inside parent body planetesimals of carbonaceous chondrites. An up-to-date thermochemical equilibrium model coupled with a 1D thermodynamic planetesimal model is used to calculate the nucleobase concentrations. Different from the previous study (Pearce & Pudritz 2016), we assume initial volatile concentrations more appropriate for the formation zone of carbonaceous chondrite parent bodies. This represents more accurately cosmochemical findings that these bodies have formed inside the inner, ∼2−5 au\sim 2\mathrm{-}5\,\mathrm{au}, warm region of the solar system. Due to these improvements, our model represents the concentrations of adenine and guanine measured in carbonaceous chondrites. Our model did not reproduce per se the measurements of uracil, cytosine, and thymine in these meteorites. This can be explained by transformation reactions between nucleobases and potential decomposition of thymine. The synthesis of prebiotic organic matter in carbonaceous asteroids could be well explained by a combination of i) radiogenic heating, ii) aqueous chemistry involving a few key processes at a specific range of radii inside planetesimals where water can exist in the liquid phase, and iii) a reduced initial volatile content (H2_2, CO, HCN, CH2_2O) of the protoplanetary disk material in the parent body region compared to the outer region of comets.Comment: Accepted for publication in The Astrophysical Journal. 30 pages, 9 figures (all colored). Supporting figure sets are available at https://doi.org/10.6084/m9.figshare.2154514

    The Holocene retreat dynamics and stability of Petermann Glacier in northwest Greenland

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    Submarine glacial landforms in fjords are imprints of the dynamic behaviour of marine-terminating glaciers and are informative about their most recent retreat phase. Here we use detailed multibeam bathymetry to map glacial landforms in Petermann Fjord and Nares Strait, northwestern Greenland. A large grounding-zone wedge (GZW) demonstrates that Petermann Glacier stabilised at the fjord mouth for a considerable time, likely buttressed by an ice shelf. This stability was followed by successive backstepping of the ice margin down the GZW’s retrograde backslope forming small retreat ridges to 680 m current depth (∼730–800 m palaeodepth). Iceberg ploughmarks occurring somewhat deeper show that thick, grounded ice persisted to these water depths before final breakup occurred. The palaeodepth limit of the recessional moraines is consistent with final collapse driven by marine ice cliff instability (MICI) with retreat to the next stable position located underneath the present Petermann ice tongue, where the seafloor is unmapped

    SARS-CoV-2 (COVID-19) Vaccine Intentions in Kentucky

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    Background: At the time of our writing, the COVID-19 pandemic continues to cause significant disruption to daily lives. In Kentucky, the burdens from this disease are higher, and vaccination rates for COVID-19 are lower, in comparison to the U.S. as a whole. Understanding vaccine intentions across key subpopulations is critical to increasing vaccination rates. Purpose: This study explores COVID-19 vaccine intentions in Kentucky across demographic subpopulations and also investigates the influences on vaccine intention of attitudes and beliefs about COVID-19. Methods: A population-based survey of 1,459 Kentucky adults was conducted between January 26 and March 20, 2021, with over-sampling of black/African American and Latino/a residents, using online and telephonic modalities. Descriptive statistics characterize the sample and overall vaccine intentions and beliefs. Multivariable linear regression models probed relationships between demographics and vaccination intentions, as well as relationships between vaccination beliefs and vaccination intention. Results: Of the 1,299 unvaccinated respondents, 53% reported intent to get vaccinated, 16% had not decided, and 31% felt they would not get vaccinated. Lower vaccination intention was independently associated with age, lower educational attainment, black/African American race, lower income, Republican political affiliation, rural residence, and several beliefs: low vaccine safety, low vaccine efficacy, the rapidity of vaccine development, and mistrust of vaccine producers. Implications: Increasing COVID-19 vaccination rates will help end this pandemic. Findings from this study can be used to tailor information campaigns aimed at helping individuals make informed decisions about COVID-19 vaccination

    Designing and implementing an assay for the detection of rare and divergent NRPS and PKS clones in European, Antarctic and Cuban soils

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    The ever increasing microbial resistome means there is an urgent need for new antibiotics. Metagenomics is an underexploited tool in the field of drug discovery. In this study we aimed to produce a new updated assay for the discovery of biosynthetic gene clusters encoding bioactive secondary metabolites. PCR assays targeting the polyketide synthases (PKS) and non-ribosomal peptide synthetases (NRPS) were developed. A range of European soils were tested for their biosynthetic potential using clone libraries developed from metagenomic DNA. Results revealed a surprising number of NRPS and PKS clones with similarity to rare Actinomycetes. Many of the clones tested were phylogenetically divergent suggesting they were fragments from novel NRPS and PKS gene clusters. Soils did not appear to cluster by location but did represent NRPS and PKS clones of diverse taxonomic origin. Fosmid libraries were constructed from Cuban and Antarctic soil samples; 17 fosmids were positive for NRPS domains suggesting a hit rate of less than 1 in 10 genomes. NRPS hits had low similarities to both rare Actinobacteria and Proteobacteria; they also clustered with known antibiotic producers suggesting they may encode for pathways producing novel bioactive compounds. In conclusion we designed an assay capable of detecting divergent NRPS and PKS gene clusters from the rare biosphere; when tested on soil samples results suggest the majority of NRPS and PKS pathways and hence bioactive metabolites are yet to be discovere
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