3,734 research outputs found

    Potholes and molehills: bias in the diagnostic performance of diffusion-tensor imaging in concussion

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    PURPOSE: To investigate the extent of bias in a clinical study involving pothole analysis of diffusion-tensor imaging (DTI) data used to quantify white matter lesion load in diseases with a heterogeneous spatial distribution of pathologic findings, such as mild traumatic brain injury (TBI), and create a mathematical model of the bias. MATERIALS AND METHODS: Use of the same reference population to define normal findings and make comparisons with a patient group introduces bias, which potentially inflates reported diagnostic performance. In this institutional review board-approved prospective observational cohort study, DTI data were obtained in 20 patients admitted to the emergency department with mild TBI and in 16 control subjects. Potholes and molehills were defined as clusters of voxels with fractional anisotropy values more than 2 standard deviations below and above the mean of the corresponding voxels in the reference population, respectively. The number and volume of potholes and molehills in the two groups were compared by using a Mann-Whitney U test. RESULTS: Standard analysis showed significantly more potholes in mild TBI than in the control group (102.5 +/- 34.3 vs 50.6 +/- 28.9, P \u3c .001). Repeat analysis by using leave-one-out cross-validation decreased the apparent difference in potholes between groups (mild TBI group, 102.5 +/- 34.3; control group, 93.4 +/- 27.2; P = .369). It was demonstrated that even with 100 subjects, this bias can decrease the voxelwise false-positive rate by more than 30% in the control group. CONCLUSION: The pothole approach to neuroimaging data may introduce bias, which can be minimized by independent training and test groups or cross-validation methods. This bias is sufficient to call into question the previously reported diagnostic performance of DTI for mild TBI

    Interactive Sonification of Grid-based Games

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    Nickerson LV, Hermann T. Interactive Sonification of Grid-based Games. In: Proceedings of the Audio Mostly Conference - A Conference on Interaction with Sound. Piteå, Sweden: Interactive Institute - Sonic Studio Piteå; 2008: 27-34.This paper presents novel designs for the sonification (auditory representation) of data from grid-based games such as Connect Four, Sudoku and others, motivated by the search for effective auditory representations that are useful for visually-impaired users as well as to support overviews in case that the visual sense is already otherwise allocated. Grid-based games are ideal to develop sonification strategies since they offer the advantage of providing an excellent test environment to evaluate the designs by measuring details of the interaction, learning, performance of the users, etc. We present in detail two new playable sonification-based audio games, and finally discuss how the approaches might generalise to general grid-based interactive exploration, e.g. for spreadsheet data

    Fiber-Reinforced Epoxy Composites and Methods of Making Same Without the Use of Oven or Autoclave

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    Method embodiments for producing a fiber-reinforced epoxy composite comprise providing a mold defining a shape for a composite, applying a fiber reinforcement over the mold, covering the mold and fiber reinforcement thereon in a vacuum enclosure, performing a vacuum on the vacuum enclosure to produce a pressure gradient, insulating at least a portion of the vacuum enclosure with thermal insulation, infusing the fiber reinforcement with a reactive mixture of uncured epoxy resin and curing agent under vacuum conditions, wherein the reactive mixture of uncured epoxy resin and curing agent generates exothermic heat, and producing the fiber-reinforced epoxy composite having a glass transition temperature of at least about 100.degree. C. by curing the fiber reinforcement infused with the reactive mixture of uncured epoxy resin and curing agent by utilizing the exothermically generated heat, wherein the curing is conducted inside the thermally insulated vacuum enclosure without utilization of an external heat source or an external radiation source

    PACAP-38 Signaling in \u3ci\u3eTetrahymena thermophila\u3c/i\u3e Involves NO and cGMP

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    Chemorepellents are signaling molecules, which have been shown to be important for mammalian neuronal development, and are presumed to have a role in protozoan defense. Tetrahymena thermophila represent a good model system in which to study repellents because of their ease of use in biochemical, behavioral, electrophysiological, and genetic analyses. In this study, we have used Tetrahymena as a model in which to study the chemorepellent, PACAP. Using behavioral and biochemical (EIA) assays, we have found that the NO/cGMP pathway plays an important role in PACAP signaling. An increase in intracellular calcium is also critical for PACAP avoidance, which appears to be mediated through a pertussis toxin-sensitive G-protein

    Specifications of standards in systems and synthetic biology: Status and developments in 2020

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    This special issue of the Journal of Integrative Bioinformatics presents papers related to the 10th COMBINE meeting together with the annual update of COMBINE standards in systems and synthetic biology

    Detection of Potential Transit Signals in the First Three Quarters of Kepler Mission Data

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    We present the results of a search for potential transit signals in the first three quarters of photometry data acquired by the Kepler Mission. The targets of the search include 151,722 stars which were observed over the full interval and an additional 19,132 stars which were observed for only 1 or 2 quarters. From this set of targets we find a total of 5,392 detections which meet the Kepler detection criteria: those criteria are periodicity of the signal, an acceptable signal-to-noise ratio, and a composition test which rejects spurious detections which contain non-physical combinations of events. The detected signals are dominated by events with relatively low signal-to-noise ratio and by events with relatively short periods. The distribution of estimated transit depths appears to peak in the range between 40 and 100 parts per million, with a few detections down to fewer than 10 parts per million. The detected signals are compared to a set of known transit events in the Kepler field of view which were derived by a different method using a longer data interval; the comparison shows that the current search correctly identified 88.1% of the known events. A tabulation of the detected transit signals, examples which illustrate the analysis and detection process, a discussion of future plans and open, potentially fruitful, areas of further research are included

    Evaluation of Microorganisms Cultured from Injured and Repressed Tissue Regeneration Sites in Endangered Giant Aquatic Ozark Hellbender Salamanders

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    Investigation into the causes underlying the rapid, global amphibian decline provides critical insight into the effects of changing ecosystems. Hypothesized and confirmed links between amphibian declines, disease, and environmental changes are increasingly represented in published literature. However, there are few long-term amphibian studies that include data on population size, abnormality/injury rates, disease, and habitat variables to adequately assess changes through time. We cultured and identified microorganisms isolated from abnormal/injured and repressed tissue regeneration sites of the endangered Ozark Hellbender, Cryptobranchus alleganiensis bishopi, to discover potential causative agents responsible for their significant decline in health and population. This organism and our study site were chosen because the population and habitat of C. a. bishopi have been intensively studied from 1969–2009, and the abnormality/injury rate and apparent lack of regeneration were established. Although many bacterial and fungal isolates recovered were common environmental organisms, several opportunistic pathogens were identified in association with only the injured tissues of C.a. bishopi. Bacterial isolates included Aeromonas hydrophila, a known amphibian pathogen, Granulicetella adiacens, Gordonai terrae, Stenotrophomonas maltophilia, Aerococcus viridans, Streptococcus pneumoniae and a variety of Pseudomonads, including Pseudomonas aeruginosa, P. stutzeri, and P. alcaligenes. Fungal isolates included species in the genera Penicillium, Acremonium, Cladosporium, Curvularia, Fusarium, Streptomycetes, and the Class Hyphomycetes. Many of the opportunistic pathogens identified are known to form biofilms. Lack of isolation of the same organism from all wounds suggests that the etiological agent responsible for the damage to C. a. bishopi may not be a single organism. To our knowledge, this is the first study to profile the external microbial consortia cultured from a Cryptobranchid salamander. The incidence of abnormalities/injury and retarded regeneration in C. a. bishopi may have many contributing factors including disease and habitat degradation. Results from this study may provide insight into other amphibian population declines

    Effectiveness and cost effectiveness of pharmacist input at the ward level: a systematic review and meta-analysis

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    Background Pharmacists play important role in ensuring timely care delivery at the ward level. The optimal level of pharmacist input, however, is not clearly defined. Objective To systematically review the evidence that assessed the outcomes of ward pharmacist input for people admitted with acute or emergent illness. Methods The protocol and search strategies were developed with input from clinicians. Medline, EMBASE, Centre for Reviews and Dissemination, The Cochrane Library, NHS Economic Evaluations, Health Technology Assessment and Health Economic Evaluations databases were searched. Inclusion criteria specified the population as adults and young people (age >16 years) who are admitted to hospital with suspected or confirmed acute or emergent illness. Only randomised controlled trials (RCTs) published in English were eligible for inclusion in the effectiveness review. Economic studies were limited to full economic evaluations and comparative cost analysis. Included studies were quality-assessed. Data were extracted, summarised. and meta-analysed, where appropriate. Results Eighteen RCTs and 7 economic studies were included. The RCTs were from USA (n=3), Sweden (n=2), Belgium (n=2), China (n=2), Australia (n=2), Denmark (n=2), Northern Ireland, Norway, Canada, UK and Netherlands. The economic studies were from UK (n=2), Sweden (n=2), Belgium and Netherlands. The results showed that regular pharmacist input was most cost effective. It reduced length-of-stay (mean= -1.74 days [95% CI: -2.76, -0.72], and increased patient and/or carer satisfaction (Relative Risk (RR) =1.49 [1.09, 2.03] at discharge). At £20,000 per quality-adjusted life-year (QALY)-gained cost-effectiveness threshold, it was either cost-saving or cost-effective (Incremental Cost Effectiveness Ratio (ICER) =£632/ QALY-gained). No evidence was found for 7-day pharmacist presence. Conclusions Pharmacist inclusion in the ward multidisciplinary team improves patient safety and satisfaction and is cost-effective when regularly provided throughout the ward stay. Research is needed to determine whether the provision of 7-day service is cost-effective.Peer reviewe

    Detection and Confirmation of Ractopamine and Its Metabolites in Horse Urine after Paylean® Administration

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    We have investigated the detection, confirmation, and metabolism of the beta-adrenergic agonist ractopamine administered as Paylean to the horse. A Testing Components Corporation enzyme-linked imunosorbent assay (ELISA) kit for ractopamine displayed linear response between 1.0 and 100 ng/ml, with an 1-50 of 10 ng/ml, and an effective screening limit of detection of 50 ng/mL. The kit was readily able to detect ractopamine equivalents in unhydrolyzed urine up to 24 h following a 300-mg oral dose. Gas chromatography-mass spectrometry (GC-MS) confirmation comprised glucuronidase treatment, solid-phase extraction, and trimethylsilyl derivatization, with selected-ion monitoring of ractopamine-tris(trimethylsilane) (TMS) m/z 267, 250, 179, and 502 ions. Quantitation was elaborated in comparison to a 445 Mw isoxsuprine-bis(TMS) internal standard monitored simultaneously. The instrumental limit of detection, defined as that number of ng on column for which signal-to-noise ratios for one or more diagnostic ions fell below a value of three, was 0.1 ng, corresponding to roughly 5 ng/mL in matrix. Based on the quantitation ions for ractopamine standards extracted from urine, standard curves showed a linear response for ractopamine concentrations between 10 and 100 ng/mL with a correlation coefficient r \u3e 0.99, whereas standards in the concentration range of 10-1000 ng/mL were fit to a second-order regression curve with r \u3e 0.99. The lower limit of detection for ractopamine in urine, defined as the lowest concentration at which the identity of ractopamine could be confirmed by comparison of diagnostic MS ion ratios, ranged between 25 and 50 ng/mL. Urine concentration of parent ractopamine 24 h post-dose was measured at 360 ng/mL by GC-MS after oral administration of 300 mg. Urinary metabolites were identified by electrospray ionization (+) tandem quadrupole mass spectrometry and were shown to include glucuronide, methyl, and mixed methyl-glucuronide conjugates. We also considered the possibility that an unusual conjugate added 113 amu to give an observed m/z 415 [M+H] species or two times 113 amu to give an m/z 528 [M+H] species with a daughter ion mass spectrum related to the previous one. Sulfate and mixed methyl-sulfate conjugates were revealed following glucuronidase treatment, suggesting that sulfation occurs in combination with glucuronidation. We noted a paired chromatographic peak phenomenon of apparent ractopamine metabolites appearing as doublets of equivalent intensity with nearly identical mass spectra on GC-MS and concluded that this phenomenon is consistent with Paylean being a mixture of RR, RS, SR, and SS diastereomers of ractopamine. The results suggest that ELISA-based screening followed by glucuronide hydrolysis, parent drug recovery, and TMS derivatization provide an effective pathway for detection and GC-MS confirmation of ractopamine in equine urine
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