2,801 research outputs found

    Effect of Prescribed Fire and Mechanical Treatments on Northern Bobwhite Occupancy in Mesic Pine Flatwoods

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    We examined whether roller-chopping, mowing, and prescribed fire used to restore groundcover in pine flatwoods habitats affected northern bobwhite (Colinus virginianus; hereafter, bobwhite) occupancy. We surveyed bobwhites using repeated point counts (n = 3), April–June each year, to determine response to prescribed fire and mechanical treatments on Osceola National Forest (Osceola, 78 plots) and St. Sebastian River Preserve State Park (Sebastian, 11 plots) in Florida, USA, 2013–2019. We measured groundcover each year at randomly placed transects within 200-m radius point-count plots. To assess the importance of management covariates, we fit single season occupancy models to predict occupancy (ψ) and detection (p). Detection probability was 0.12 (standard error [SE] = 0.05) and 0.35 (SE = 0.05) on Osceola and Sebastian, respectively. Modeled occupancy on both sites was best predicted by presence of roller-chopping, years since fire, and year. Predicted occupancy was highest on plots with 1 year since fire (Osceola, 0.22 [SE = 0.10]; Sebastian, 0.67 [SE = 0.18]). Predicted occupancy was higher on roller-chopped plots (Osceola, 0.33 [SE = 0.15]; Sebastian, 0.85 [SE = 0.15]) than on mowed (Osceola, 0.08 [SE = 0.03]) or untreated plots (Osceola, 0.07 [SE = 0.03]; Sebastian, 0.38 [SE = 0.34]). Roller-chopping and fire reduced density of palmetto (Seranoa spp.)-shrub vegetation and increased grasses and forbs. To increase bobwhite occupancy and improve habitat suitability of degraded mesic pine flatwoods, we recommend roller-chopping and a 2-year fire frequency

    Flexibility in Faculty Work-Life Policies at Medical Schools in the Big Ten Conference

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    Purpose: Women lag behind men in several key academic indicators, such as advancement, retention, and securing leadership positions. Although reasons for these disparities are multifactorial, policies that do not support work-life integration contribute to the problem. The objective of this descriptive study was to compare the faculty work-life policies among medical schools in the Big Ten conference. Methods: Each institution's website was accessed in order to assess its work-life policies in the following areas: maternity leave, paternity leave, adoption leave, extension of probationary period, part-time appointments, part-time benefits (specifically health insurance), child care options, and lactation policy. Institutions were sent requests to validate the online data and supply additional information if needed. Results: Each institution received an overall score and subscale scores for family leave policies and part-time issues. Data were verified by the human resources office at 8 of the 10 schools. Work-life policies varied among Big Ten schools, with total scores between 9.25 and 13.5 (possible score: 0–21; higher scores indicate greater flexibility). Subscores were not consistently high or low within schools. Conclusions: Comparing the flexibility of faculty work-life policies in relation to other schools will help raise awareness of these issues and promote more progressive policies among less progressive schools. Ultimately, flexible policies will lead to greater equity and institutional cultures that are conducive to recruiting, retaining, and advancing diverse faculty

    A proteomic approach to identify endosomal cargoes controlling cancer invasiveness

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    We have previously shown that Rab17 - a small GTPase associated with epithelial polarity - is specifically suppressed by ERK2 signalling to promote an invasive phenotype. However, the mechanisms through which Rab17 loss permits invasiveness, and the endosomal cargoes that are responsible for mediating this are not known. Using quantitative mass spectrometry-based proteomics, we have found that knockdown of Rab17 leads to highly selective reduction in the cellular levels of a v-SNARE (Vamp8). Moreover, proteomics and immunofluorescence indicate that Vamp-8 is associated with Rab17 at late endosomes. Reduced levels of Vamp8 promote transition between ductal carcinoma in situ (DCIS) and a more invasive phenotype. We developed an unbiased proteomic approach to elucidate the complement of receptors that redistributes between endosomes and the plasma membrane, and have pin-pointed neuropilin-2 (NRP2) as a key pro-invasive cargo of Rab17/Vamp8-regulated trafficking. Indeed, reduced Rab17 or Vamp8 levels lead to increased mobilisation of NRP2-containing late endosomes and upregulated cell surface expression of NRP2. Finally, we show that NRP2 is required for the basement membrane disruption which accompanies transition between DCIS and a more invasive phenotype

    Measuring human rights abuse from access to information requests

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    Existing measures of human rights abuses are often only available at the country-year level. Several more fine-grained measures exhibit spatio-temporal inaccuracies or reporting biases due to the primary sources upon which they rely. To address these challenges, and to increase the diversity of available human rights measures more generally, this study provides the first quantitative effort to measure human rights abuses from textual records of citizen-government interactions. Using a dataset encompassing over 1.5 million access-to-information (ATI) requests made to the Mexican federal government from June 2003 onward, supervised classification is used to identify the subset of these requests that pertain to human rights abuses of various types. The results from this supervised machine learning exercise are validated against (i) gold standard ATI requests pertaining to past human rights abuses in Mexico and (ii) several accepted external measures of sub-national and sub-annual human rights abuses. In doing so, we demonstrate that the measurement of human rights abuses from citizen-submitted ATI request texts can provide measures of human rights abuse that exhibit both high validity and notable spatio-temporal specificity, relative to existent human rights datasets and variables

    Gas-Phase Deposition of Gold Nanoclusters to Produce Heterogeneous Glycerol Oxidation Catalysts

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    Gold nanoparticles prepared by colloidal methods are effective catalysts for selective glycerol oxidation under basic conditions. Large-scale synthesis of catalysts by wet chemical methods leads to large amounts of waste and can result in polymer or salt residues remaining on the catalyst. In contrast, gas-phase cluster deposition (cluster beam deposition) offers a solvent-free method to synthesize controlled nanoparticles/clusters. We show that the deposition of bare gas-phase gold clusters onto carbon powder leads to a catalyst comparable to that prepared by colloidal methods. This shows the feasibility of the synthesis method to produce oxidation catalysts with reduced waste

    Southern California margin benthic foraminiferal assemblages record recent centennial-scale changes in oxygen minimum zone

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    Microfossil assemblages provide valuable records to investigate variability in continental margin biogeochemical cycles, including dynamics of the oxygen minimum zone (OMZ). Analyses of modern assemblages across environmental gradients are necessary to understand relationships between assemblage characteristics and environmental factors. Five cores were analyzed from the San Diego margin (32∘42′00′′ N, 117∘30′00′′ W; 300–1175 m water depth) for core top benthic foraminiferal assemblages to understand relationships between community assemblages and spatial hydrographic gradients as well as for down-core benthic foraminiferal assemblages to identify changes in the OMZ through time. Comparisons of benthic foraminiferal assemblages from two size fractions (63–150 and \u3e150 µm) exhibit similar trends across the spatial and environmental gradient or in some cases exhibit more pronounced spatial trends in the \u3e150 µm fraction. A range of species diversity exists within the modern OMZ (1.910–2.586 H, Shannon index), suggesting that diversity is not driven by oxygenation alone. We identify two hypoxic-associated species (B. spissa and U. peregrina), one oxic-associated species (G. subglobosa) and one OMZ edge-associated species (B. argentea). Down-core analysis of indicator species reveals variability in the upper margin of the OMZ (528 m water depth) while the core of the OMZ (800 m) and below the OMZ (1175 m) remained stable in the last 1.5 kyr. We document expansion of the upper margin of the OMZ beginning 400 BP on the San Diego margin that is synchronous with other regional records of oxygenation

    A signal sequence suppressor mutant that stabilizes an assembled state of the twin arginine translocase

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    The twin-arginine protein translocation (Tat) system mediates transport of folded proteins across the cytoplasmic membrane of bacteria and the thylakoid membrane of chloroplasts. The Tat system of Escherichia coli is made up of TatA, TatB and TatC components. TatBC comprise the substrate receptor complex, and active Tat translocases are formed by the substrate-induced association of TatA oligomers with this receptor. Proteins are targeted to TatBC by signal peptides containing an essential pair of arginine residues. We isolated substitutions, locating to the transmembrane helix of TatB that restored transport activity to Tat signal peptides with inactivating twin arginine substitutions. A subset of these variants also suppressed inactivating substitutions in the signal peptide binding site on TatC. The suppressors did not function by restoring detectable signal peptide binding to the TatBC complex. Instead, site specific crosslinking experiments indicate that the suppressor substitutions induce conformational change in the complex and movement of the TatB subunit. The TatB F13Y substitution was associated with the strongest suppressing activity, even allowing transport of a Tat substrate lacking a signal peptide. In vivo analysis using a TatA-YFP fusion showed that the TatB F13Y substitution resulted in signal peptide independent assembly of the Tat translocase. We conclude that Tat signal peptides play roles in substrate targeting and in triggering assembly of the active translocase

    Changes in presentations with features potentially indicating cancer in primary care during the COVID-19 pandemic:a retrospective cohort study

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    OBJECTIVES: To investigate how the COVID-19 pandemic affected the number of people aged 50+ years presenting to primary care with features that could potentially indicate cancer, and to explore how reporting differed by patient characteristics and in face-to-face vs remote consultations. DESIGN, SETTING AND PARTICIPANTS: A retrospective cohort study of general practitioner (GP), nurse and paramedic primary care consultations in 21 practices in South-West England covering 123 947 patients. The models compared potential cancer indicators reported in April–July 2019 with April–July 2020. MAIN OUTCOME MEASURES: Potential indicators of cancer were identified using code lists for symptoms, signs, test results and diagnoses listed in the National Institute for Health and Care Excellence suspected cancer referral guidance (NG12). RESULTS: During April–July 2019, 17% of registered patients aged 50+ years reported a potential cancer indicator in a consultation with a GP or nurse. During April–July 2020, this reduced to 11% (incidence rate ratio (IRR) 0.64, 95% CI 0.62 to 0.67, p<0.001). Reductions in potential cancer indicators were stable across age group, sex, ethnicity, index of multiple deprivation quintile and shielding status, but less marked in patients with mental health conditions than without (IRR 0.75, 95% CI 0.72 to 0.79, interaction p<0.001). Proportions of GP consultations with potential indicators of cancer reduced between 2019 and 2020 for face-to-face consultations (IRR 0.84, 95% CI 0.76 to 0.92, p<0.001) and increased for remote consultations (IRR 1.17, 95% CI 1.07 to 1.29, p=0.001), although it remained lower in remote consulting than face-to-face in April–July 2020. This difference was greater for nurse/paramedic consultations (face-to-face: IRR 0.61, 95% CI 0.44 to 0.83, p=0.002; remote: IRR 1.60, 95% CI 1.10 to 2.333, p=0.014). CONCLUSION: The number of patients consulting with presentations that could potentially indicate cancer reduced during the first wave of the COVID-19 pandemic. Patients should be encouraged to continue contacting primary care for persistent signs and symptoms, and GPs and nurses should be encouraged to probe patients for further information during remote consulting, in the absence of non-verbal cues
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