548 research outputs found

    Conserving the Stage: Climate Change and the Geophysical Underpinnings of Species Diversity

    Get PDF
    Conservationists have proposed methods for adapting to climate change that assume species distributions are primarily explained by climate variables. The key idea is to use the understanding of species-climate relationships to map corridors and to identify regions of faunal stability or high species turnover. An alternative approach is to adopt an evolutionary timescale and ask ultimately what factors control total diversity, so that over the long run the major drivers of total species richness can be protected. Within a single climatic region, the temperate area encompassing all of the Northeastern U.S. and Maritime Canada, we hypothesized that geologic factors may take precedence over climate in explaining diversity patterns. If geophysical diversity does drive regional diversity, then conserving geophysical settings may offer an approach to conservation that protects diversity under both current and future climates. Here we tested how well geology predicts the species diversity of 14 US states and three Canadian provinces, using a comprehensive new spatial dataset. Results of linear regressions of species diversity on all possible combinations of 23 geophysical and climatic variables indicated that four geophysical factors; the number of geological classes, latitude, elevation range and the amount of calcareous bedrock, predicted species diversity with certainty (adj. R2 = 0.94). To confirm the species-geology relationships we ran an independent test using 18,700 location points for 885 rare species and found that 40% of the species were restricted to a single geology. Moreover, each geology class supported 5–95 endemic species and chi-square tests confirmed that calcareous bedrock and extreme elevations had significantly more rare species than expected by chance (P<0.0001), strongly corroborating the regression model. Our results suggest that protecting geophysical settings will conserve the stage for current and future biodiversity and may be a robust alternative to species-level predictions

    A Simple Scoring System to Differentiate between Relapse and Re-Infection in Patients with Recurrent Melioidosis

    Get PDF
    Melioidosis is a serious infectious disease caused by the Gram-negative bacterium, Burkholderia pseudomallei. This organism is present in the environment in areas where melioidosis is endemic (most notably East Asia and Northern Australia), and infection is acquired following bacterial inoculation or inhalation. Despite prolonged oral eradicative treatment, recurrent melioidosis occurs in approximately 10% of survivors of acute melioidosis. Recurrent melioidosis can be caused by relapse (failure of initial eradicative treatment) or re-infection with a new infection. The aim of this study was to develop a simple scoring system to distinguish between re-infection and relapse, since this has implications for antimicrobial treatment of the recurrent episode, but telling the two apart normally requires bacterial genotyping. A prospective study of melioidosis patients in NE Thailand conducted between 1986 and 2005 identified 141 patients with recurrent melioidosis. Of these, 92 patients had relapse and 49 patients had re-infection as confirmed by genotyping techniques. We found that relapse was associated with previous inadequate treatment and shorter time to clinical features of recurrence, while re-infection was associated with renal insufficiency and presentation during the rainy season. A simple scoring index to help distinguish between relapse and re-infection was developed to provide important bedside information where rapid bacterial genotyping is unavailable. Guidelines are provided on how this scoring system could be implemented

    Differences in the gas and dust distribution in the transitional disk of a sun-like young star, PDS 70

    Get PDF
    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordThe American Astronomical Society. All rights reserved. We present ALMA 0.87 mm continuum, HCO + J = 4-3 emission line, and CO J = 3-2 emission line data of the disk of material around the young, Sun-like star PDS 70. These data reveal the existence of a possible two-component transitional disk system with a radial dust gap of 0.″42 ±0.″05, an azimuthal gap in the HCO + J = 4-3 moment zero map, as well as two bridge-like features in the gas data. Interestingly these features in the gas disk have no analog in the dust disk making them of particular interest. We modeled the dust disk using the Monte Carlo radiative transfer code HOCHUNK3D using a two-disk component. We find that there is a radial gap that extends from 15 to 60 au in all grain sizes, which differs from previous work.This work is supported supported by the NASA XRP grants NNX17AF88G and NNX16AJ75G. MC thanks the support from the Centro de Astrofísica de Valparaíso. S.K. acknowledges support from an STFC Rutherford Fellowship (ST/J004030/1) and ERC Starting Grant (Grant Agreement No. 639889). This work is supported by the Astrobiology Center Program of National Institutes of Natural Sciences (NINS) (Grant Number: AB281013) and by MEXT KAKENHI No. 17K05399 (EA). Y.H. is currently supported by Jet Propulsion Laboratory, California Institute of Technology, under a contract from NASA. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2015.1.00888.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, In

    Functional assessment of older patients in the emergency department: comparison between standard instruments, medical records and physicians' perceptions

    Get PDF
    BACKGROUND: We evaluated the accuracy of physician recognition of functional status impairment in older emergency departments (ED) patients. In particular, we evaluated the accuracy of medical records (a comparison of the information in the medical record with the functional status based on proxy interviews), and the accuracy of physician knowledge (a comparison of the information obtained from the responsible physician with the functional status based on proxy interviews). METHODS: Cross-sectional study on 101 frail older patients selected at random from among those attending ED, their ED physicians, and respondents. The study was conducted at ED in four general university teaching hospitals in a city, from July through November 2003. Functional data shown on patients' medical records were compared against functional data obtained from respondents (family members), using Kendall's Tau-b statistic. In addition patients' Katz Indices (which assesses six basic activities of daily living – basic ADL) based on interviews with ED physicians were compared against those obtained from respondents, using the coefficient of concordance weighted kappa (κ). Each patient and his respondent were paired with a single physician. RESULTS: The correlation between information on dependence for basic ADL obtained from medical records and that furnished by respondents, was 0.41 (95% CI 0.27–0.55). Concordance between the respective Katz Indices obtained from physicians and respondents was 0.47 (95% CI 0.38–0.57). CONCLUSION: Older subjects' functional status is not properly assessed by emergency department physicians

    Burkholderia pseudomallei Is Spatially Distributed in Soil in Northeast Thailand

    Get PDF
    Melioidosis is a severe infection caused by the environmental bacterium Burkholderia pseudomallei. Soil sampling is important to identify geographic regions where humans and animals are at risk of exposure. The purpose of this study was to examine a factor that has a major bearing on the accuracy of soil sampling: the spatial distribution of B. pseudomallei in soil of a specified sampling site. Soil sampling was performed using a fixed-interval grid of 100 sampling points in each of two sites (disused land and rice field) in northeast Thailand, and the presence and amount of B. pseudomallei determined using culture. Mapping of the presence and B. pseudomallei count demonstrated that samples taken from areas adjacent to sampling points that were culture positive (negative) for B. pseudomallei were also likely to be culture positive (negative), and samples taken from areas adjacent to sampling points with a high (low) B. pseudomallei count were also likely to yield a high (low) count (spatial autocorrelation). These data were used as the basis for highlighting several pitfalls in current approaches to soil sampling, together with a discussion of the suitability of a range of sampling strategies in different geographical locations and for different study objectives

    New Forearm Elements Discovered of Holotype Specimen Australovenator wintonensis from Winton, Queensland, Australia

    Get PDF
    New skeletal elements are reported of the holotype specimen Australovenator wintonensis, from the type locality, near Winton, central western Queensland. New elements include left and right humeri, right radius, right radiale, right distal carpal 1, near complete right metacarpal I, left manual phalanx II-1, left manual phalanx II-2, near complete left manual phalanx II-3 and a left manual phalanx III-3. These new elements combined with those previously described are compared against other neovenatorids

    Evaluating the impact of MEDLINE filters on evidence retrieval: study protocol

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Rather than searching the entire MEDLINE database, clinicians can perform searches on a filtered set of articles where relevant information is more likely to be found. Members of our team previously developed two types of MEDLINE filters. The 'methods' filters help identify clinical research of high methodological merit. The 'content' filters help identify articles in the discipline of renal medicine. We will now test the utility of these filters for physician MEDLINE searching.</p> <p>Hypothesis</p> <p>When a physician searches MEDLINE, we hypothesize the use of filters will increase the number of relevant articles retrieved (increase 'recall,' also called sensitivity) and decrease the number of non-relevant articles retrieved (increase 'precision,' also called positive predictive value), compared to the performance of a physician's search unaided by filters.</p> <p>Methods</p> <p>We will survey a random sample of 100 nephrologists in Canada to obtain the MEDLINE search that they would first perform themselves for a focused clinical question. Each question we provide to a nephrologist will be based on the topic of a recently published, well-conducted systematic review. We will examine the performance of a physician's unaided MEDLINE search. We will then apply a total of eight filter combinations to the search (filters used in isolation or in combination). We will calculate the recall and precision of each search. The filter combinations that most improve on unaided physician searches will be identified and characterized.</p> <p>Discussion</p> <p>If these filters improve search performance, physicians will be able to search MEDLINE for renal evidence more effectively, in less time, and with less frustration. Additionally, our methodology can be used as a proof of concept for the evaluation of search filters in other disciplines.</p

    Materials Characterization Using Acoustic Nonlinearity Parameters and Harmonic Generation: Effects of Crystalline and Amorphous Structures

    Get PDF
    The importance of nonlinearity in the description of material behavior is gaining widespread attention. Nonlinearity plays a major, if not dominating, role in a number of material properties. For example, properties that are important in engineering design such as thermal expansion or the pressure dependence of optical refraction are inherently nonlinear [1]. New assembley techniques such as the use of ultrasonic gauges to determine the loading of critical fasteners depend upon nonlinear properties of the fasteners [2]. Areas of considerable fundamental interest in nonlinearity include lattice dynamics [3], radiation stress in solids [4,5], and nonlinear optics [6

    Search for CP violation in D+→ϕπ+ and D+s→K0Sπ+ decays

    Get PDF
    A search for CP violation in D + → ϕπ + decays is performed using data collected in 2011 by the LHCb experiment corresponding to an integrated luminosity of 1.0 fb−1 at a centre of mass energy of 7 TeV. The CP -violating asymmetry is measured to be (−0.04 ± 0.14 ± 0.14)% for candidates with K − K + mass within 20 MeV/c 2 of the ϕ meson mass. A search for a CP -violating asymmetry that varies across the ϕ mass region of the D + → K − K + π + Dalitz plot is also performed, and no evidence for CP violation is found. In addition, the CP asymmetry in the D+s→K0Sπ+ decay is measured to be (0.61 ± 0.83 ± 0.14)%
    corecore