3,835 research outputs found
Efficient depletion of host DNA contamination in malaria clinical sequencing.
The cost of whole-genome sequencing (WGS) is decreasing rapidly as next-generation sequencing technology continues to advance, and the prospect of making WGS available for public health applications is becoming a reality. So far, a number of studies have demonstrated the use of WGS as an epidemiological tool for typing and controlling outbreaks of microbial pathogens. Success of these applications is hugely dependent on efficient generation of clean genetic material that is free from host DNA contamination for rapid preparation of sequencing libraries. The presence of large amounts of host DNA severely affects the efficiency of characterizing pathogens using WGS and is therefore a serious impediment to clinical and epidemiological sequencing for health care and public health applications. We have developed a simple enzymatic treatment method that takes advantage of the methylation of human DNA to selectively deplete host contamination from clinical samples prior to sequencing. Using malaria clinical samples with over 80% human host DNA contamination, we show that the enzymatic treatment enriches Plasmodium falciparum DNA up to ∼9-fold and generates high-quality, nonbiased sequence reads covering >98% of 86,158 catalogued typeable single-nucleotide polymorphism loci
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Cutting performance comparison of low-kickback saw chain
Kickback is the leading cause of the most severe and traumatic chainsaw-related injuries. As a result, safety standards require chainsaw manufacturers to produce low-kickback saw chain. In order to understand the tradeoffs in current state-of-the-art saw chain, a comparison study was conducted on a custom test apparatus using four different saw chains, all with the same cutter geometry but different low-kickback chain features. Two modes of cutting were studied: nose-clear down bucking and boring. Cutting performance for boring with a chainsaw has not been studied previously. Regression modeling was used to generate cutting force and cutting efficiency trend lines for each of the different saw chains and cutting modes. In nose-clear down bucking, it was found that operator effort and cutting efficiency of a low-kickback chain with bumper drive links was of near-equal performance to that of a non-low-kickback chain (having no low-kickback features). In boring, all types of low-kickback saw chain elements required markedly higher operator effort and had lower cutting efficiency that of non-lowkickback saw chain. Furthermore, a substantial difference in cutting forces was found between differing designs of bumper drive link elements in both nose-clear down bucking and boring, highlighting the importance of proper bumper link geometry. Using these results and considering that the boring mode of operation is for experienced users, the casual chainsaw operator should always prioritize safety by using a low-kickback saw chain while professional users should select the chain that best suits their current cutting needs
Any health care reform must allow continuation of robust Medicaid Buy-In programs for working people with disabilities
National health care reform must meet the unique health care needs of people with disabilities. However, obtaining health care coverage for a person with disabilities can be challenging in an employer-based health insurance environment. The final healthcare reform act must ensure that working people with disabilities retain the options they currently have to participate; any legislation should embed Medicaid Buy-in cocerage and provide states the flexibility they need to support individuals with disabilities in employmen
A Flexible Platform for Biofeedback-driven Control and Personalization of Electrical Nerve Stimulation Therapy
Electrical vagus nerve stimulation is a treatment alternative for many epileptic and depressed patients whose symptoms are not well managed with pharmaceutical therapy. However, the fixed stimulus, open loop dosing mechanism limits its efficacy and precludes major advances in the quality of therapy. A real-time, responsive form of vagus nerve stimulation is needed to control nerve activation according to therapeutic need. This personalized approach to therapy will improve efficacy and reduce the number and severity of side effects. We present autonomous neural control, a responsive, biofeedback-driven approach that uses the degree of measured nerve activation to control stimulus delivery. We demonstrate autonomous neural control in rats, showing that it rapidly learns how to most efficiently activate any desired proportion of vagal A, B, and/or C fibers over time. This system will maximize efficacy by minimizing patient response variability and by minimizing therapeutic failures resulting from longitudinal decreases in nerve activation with increasing durations of treatment. The value of autonomous neural control equally applies to other applications of electrical nerve stimulation
Optical resonance imaging: An optical analog to MRI with sub-diffraction-limited capabilities
We propose here optical resonance imaging (ORI), a direct optical analog to magnetic resonance imaging (MRI). The proposed pulse sequence for ORI maps space to time and recovers an image from a heterodyne-detected third-order nonlinear photon echo measurement. As opposed to traditional photon echo measurements, the third pulse in the ORI pulse sequence has significant pulse-front tilt that acts as a temporal gradient. This gradient couples space to time by stimulating the emission of a photon echo signal from different lateral spatial locations of a sample at different times, providing a widefield ultrafast microscopy. We circumvent the diffraction limit of the optics by mapping the lateral spatial coordinate of the sample with the emission time of the signal, which can be measured to high precision using interferometric heterodyne detection. This technique is thus an optical analog of MRI, where magnetic-field gradients are used to localize the spin-echo emission to a point below the diffraction limit of the radio-frequency wave used. We calculate the expected ORI signal using 15 fs pulses and 87° of pulse-front tilt, collected using f/2 optics and find a two-point resolution 275 nm using 800 nm light that satisfies the Rayleigh criterion. We also derive a general equation for resolution in optical resonance imaging that indicates that there is a possibility of superresolution imaging using this technique. The photon echo sequence also enables spectroscopic determination of the input and output energy. The technique thus correlates the input energy with the final position and energy of the exciton
Rapid weed adaptation and range expansion in response to agriculture over the past two centuries
North America has experienced a massive increase in cropland use since 1800, accompanied more recently by the intensification of agricultural practices. Through genome analysis of present-day and historical samples spanning environments over the past two centuries, we studied the effect of these changes in farming on the extent and tempo of evolution across the native range of the common waterhemp (Amaranthus tuberculatus), a now pervasive agricultural weed. Modern agriculture has imposed strengths of selection rarely observed in the wild, with notable shifts in allele frequency trajectories since agricultural intensification in the 1960s. An evolutionary response to this extreme selection was facilitated by a concurrent human-mediated range shift. By reshaping genome-wide diversity across the landscape, agriculture has driven the success of this weed in the 21st century
Aquilegia, Vol. 13 No. 2, March-April 1989: Newsletter of the Colorado Native Plant Society
https://epublications.regis.edu/aquilegia/1045/thumbnail.jp
Classification of Aerosol Retrievals from Spaceborne Polarimetry Using a Multiparameter Algorithm
In this presentation, we demonstrate application of a new aerosol classification algorithm to retrievals from the POLDER-3 polarimter on the PARASOL spacecraft. Motivation and method: Since the development of global aerosol measurements by satellites and AERONET, classification of observed aerosols into several types (e.g., urban-industrial, biomass burning, mineral dust, maritime, and various subtypes or mixtures of these) has proven useful to: understanding aerosol sources, transformations, effects, and feedback mechanisms; improving accuracy of satellite retrievals and quantifying assessments of aerosol radiative impacts on climate
Copernicus Climate Change Service (C3S) Global Satellite Observations of Atmospheric Carbon Dioxide and Methane
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Single nucleotide polymorphisms in the fatty acid binding protein 4, fatty acid synthase and stearoyl-CoA desaturase genes influence carcass characteristics of tropical crossbred beef steers
This study explored the identification of single nucleotide polymorphisms (SNP) in fatty acid binding protein 4 (FABP4), stearoyl-CoA desaturase (SCD), and fatty acid synthase (FASN) genes that may influence the carcass traits of tropical crossbred beef cattle. The hypothesis tested was that SNP in the FABP4, SCD, and FASN genes are associated with chiller-assessed carcass traits of tropically adapted northern Australian crossbred beef cattle. Fifty Bos indicus and Bos taurus crossbred steers were backgrounded on either buffel grass only, or buffel grass and desmanthus mixed pastures for 147 days and finished in a commercial feedlot for 110 days. Steers were slaughtered within 48 h of leaving the feedlot within a lairage period not exceeding 12 h and carcasses graded 12 h after slaughter. Next-generation sequencing of the FASN, FABP4, and SCD genes identified multiple SNP loci that were correlated and significantly associated with carcass traits. The FABP4 g.44677205A>G locus was significantly associated with hump height and correlated with loin eye muscle area (EMA; p A locus was associated with subcutaneous fat depth and marbling score (p < 0.05). The CC genotype had a higher subcutaneous fat depth and marbling score (p < 0.05) than the AA genotype. Significant correlations were observed between carcass marbling score and subcutaneous fat depth within the FASN SNP locus (p < 0.05). Therefore, the hypothesis that SNP in the FABP4, SCD, and FASN genes are associated with chiller-assessed carcass traits of tropically adapted northern Australian crossbred beef cattle was accepted. These findings suggest that SNP in the FABP4, SCD, and FASN genes may be used in carcass grading and meat quality improvement through marker-assisted selection of northern Australian crossbred beef cattle
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