1,707 research outputs found

    Conservation genetics and phylogeography of endangered and endemic shrub Tetraena mongolica (Zygophyllaceae) in Inner Mongolia, China

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    <p>Abstract</p> <p>Background</p> <p><it>Tetraena mongolica </it>(Zygophyllaceae), an endangered endemic species in western Inner Mongolia, China. For endemic species with a limited geographical range and declining populations, historical patterns of demography and hierarchical genetic structure are important for determining population structure, and also provide information for developing effective and sustainable management plans. In this study, we assess genetic variation, population structure, and phylogeography of <it>T. mongolica </it>from eight populations. Furthermore, we evaluate the conservation and management units to provide the information for conservation.</p> <p>Results</p> <p>Sequence variation and spatial apportionment of the <it>atp</it>B-<it>rbc</it>L noncoding spacer region of the chloroplast DNA were used to reconstruct the phylogeography of <it>T. mongolica</it>. A total of 880 bp was sequenced from eight extant populations throughout the whole range of its distribution. At the cpDNA locus, high levels of genetic differentiation among populations and low levels of genetic variation within populations were detected, indicating that most seed dispersal was restricted within populations.</p> <p>Conclusions</p> <p>Demographic fluctuations, which led to random losses of genetic polymorphisms from populations, due to frequent flooding of the Yellow River and human disturbance were indicated by the analysis of BEAST skyline plot. Nested clade analysis revealed that restricted gene flow with isolation by distance plus occasional long distance dispersal is the main evolutionary factor affecting the phylogeography and population structure of <it>T</it>. <it>mongolica</it>. For setting a conservation management plan, each population of <it>T</it>. <it>mongolica </it>should be recognized as a conservation unit.</p

    Clinical Characteristics and Risk Factors for Mortality in Patients with Meningitis Caused by Staphylococcus aureus and Vancomycin Minimal Inhibitory Concentrations Against These Isolates

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    Background/PurposeBacterial meningitis caused by Staphylococcus aureus is uncommon but has a high mortality rate. The aims of this study were to better understand the clinical manifestations of S. aureus meningitis, to identify the risk factors for mortality in the affected patients, and to determine the levels of vancomycin minimal inhibitory concentrations (MICs) against these pathogens.MethodsA retrospective study of patients with S. aureus meningitis hospitalized between December 2000 and December 2008 was made, and vancomycin MICs against S. aureus isolates was determined using Etest.ResultsAmong 37 patients with S. aureus meningitis, fever was most commonly observed. Twenty-six patients (70.3%) had received prior neurosurgery, and 24 (64.9%) patients were suffering from methicillin-resistant S. aureus (MRSA) infections. The vancomycin MIC of 2 μg/mL was found in 23 (74.2%) of 31 S. aureus isolates available for testing. Excluding three patients who did not receive antibiotics for their S. aureus meningitis the mortality rate was 35.3% in the 34 remaining patients, with concurrent infective endocarditis an independent risk factor for mortality (odds ratio = 21.00; 95% confidence interval, 1.834-240.515; p = 0.01).ConclusionPatients with S. aureus meningitis and concurrent infective endocarditis were at a higher risk of mortality. A vancomycin MIC of 2 μg/mL against a substantial number of S. aureus isolates that grew from the cerebrospinal fluid suggests the importance of obtaining trough vancomycin concentrations of 15-20 μg/mL for the treatment of MRSA meningitis

    Iterative Scale-Up ExpansionIoU and Deep Features Association for Multi-Object Tracking in Sports

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    Multi-object tracking algorithms have made significant advancements due to the recent developments in object detection. However, most existing methods primarily focus on tracking pedestrians or vehicles, which exhibit relatively simple and regular motion patterns. Consequently, there is a scarcity of algorithms that address the tracking of targets with irregular or non-linear motion, such as multi-athlete tracking. Furthermore, popular tracking algorithms often rely on the Kalman filter for object motion modeling, which fails to track objects when their motion contradicts the linear motion assumption of the Kalman filter. Due to this reason, we proposed a novel online and robust multi-object tracking approach, named Iterative Scale-Up ExpansionIoU and Deep Features for multi-object tracking. Unlike conventional methods, we abandon the use of the Kalman filter and propose utilizing the iterative scale-up expansion IoU. This approach achieves superior tracking performance without requiring additional training data or adopting a more robust detector, all while maintaining a lower computational cost compared to other appearance-based methods. Our proposed method demonstrates remarkable effectiveness in tracking irregular motion objects, achieving a score of 75.3% in HOTA. It outperforms all state-of-the-art online tracking algorithms on the SportsMOT dataset, covering various kinds of sport scenarios

    Fatal myocardial microabscesses caused by methicillin-resistant Staphylococcus aureus in a burn patient

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    AbstractBacteremia- or sepsis-associated myocardial abscess is often an incidental postmortem diagnosis in patients who die of overwhelming septicemia. Myocardial abscess is more rarely the immediate cause of death as a consequence of abscess rupture or the cause of arrhythmia. We report a 66-year-old female who succumbed to sudden cardiac death with a hemodynamically stable methicillin-resistant Staphylococcus aureus (MRSA) bacteremia, while in recovery after an accidental thermal burn. Autopsy revealed extensive myocardial abscesses and an abscess in the pineal gland. Myocardial microabscesses should be considered a rare cause of sudden cardiac death in patients with hemodynamically stable MRSA bacteremia

    MiniSUPERB: Lightweight Benchmark for Self-supervised Speech Models

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    Self-supervised learning (SSL) is a popular research topic in speech processing. Successful SSL speech models must generalize well. SUPERB was proposed to evaluate the ability of SSL speech models across many speech tasks. However, due to the diversity of tasks, the evaluation process requires huge computational costs. We present MiniSUPERB, a lightweight benchmark that efficiently evaluates SSL speech models with comparable results to SUPERB while greatly reducing the computational cost. We select representative tasks and sample datasets and extract model representation offline, achieving 0.954 and 0.982 Spearman's rank correlation with SUPERB Paper and SUPERB Challenge, respectively. In the meanwhile, the computational cost is reduced by 97% in regard to MACs (number of Multiply-ACcumulate operations) in the tasks we choose. To the best of our knowledge, this is the first study to examine not only the computational cost of a model itself but the cost of evaluating it on a benchmark

    The Non-linear Relationship between Muscle Voluntary Activation Level and Voluntary Force Measured by the Interpolated Twitch Technique

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    Interpolated twitch technique (ITT) is a non-invasive method for assessing the completeness of muscle activation in clinical settings. Voluntary activation level (VA), measured by ITT and estimated by a conventional linear model, was reported to have a non-linear relationship with true voluntary contraction force at higher activation levels. The relationship needs to be further clarified for the correct use by clinicians and researchers. This study was to established a modified voluntary activation (modified VA) and define a valid range by fitting a non-linear logistic growth model. Eight healthy male adults participated in this study. Each subject performed three sets of voluntary isometric ankle plantar flexions at 20, 40, 60, 80 and 100% maximal voluntary contraction (MVC) with real-time feedback on a computer screen. A supramaximal electrical stimulation was applied on tibia nerve at rest and during contractions. The estimated VA was calculated for each contraction. The relationship between the estimated VA and the actual voluntary contraction force was fitted by a logistic growth model. The result showed that according to the upper and lower limit points of the logistic curve, the valid range was between the 95.16% and 10.55% MVC. The modified VA estimated by this logistic growth model demonstrated less error than the conventional model. This study provided a transfer function for the voluntary activation level and defined the valid range which would provide useful information in clinical applications
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