1,267 research outputs found

    Manual para construção de um secador de frutas a nível do produtor rural.

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    Descrição do equipamento. Processamento. Vantagens. Desempenho do equipamento. Relação do material para a construção do equipamento.bitstream/item/65373/1/CTAA-DOCUMENTOS-06-MANUAL-PARA-CONSTRUCAO-DE-UM-SECADOR-DE-FRUTAS-A-NIVEL-DO-PRODUTOR-RURAL-FL-02.pd

    Pherotype Polymorphism in Streptococcus pneumoniae Has No Obvious Effects on Population Structure and Recombination.

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    Natural transformation in the Gram-positive pathogen Streptococcus pneumoniae occurs when cells become "competent," a state that is induced in response to high extracellular concentrations of a secreted peptide signal called competence stimulating peptide (CSP) encoded by the comC locus. Two main CSP signal types (pherotypes) are known to dominate the pherotype diversity across strains. Using 4,089 fully sequenced pneumococcal genomes, we confirm that pneumococcal populations are highly genetically structured and that there is significant variation among diverged populations in pherotype frequencies; most carry only a single pherotype. Moreover, we find that the relative frequencies of the two dominant pherotypes significantly vary within a small range across geographical sites. It has been variously proposed that pherotypes either promote genetic exchange among cells expressing the same pherotype, or conversely that they promote recombination between strains bearing different pherotypes. We attempt to distinguish these hypotheses using a bioinformatics approach by estimating recombination frequencies within and between pherotypes across 4,089 full genomes. Despite underlying population structure, we observe extensive recombination between populations; additionally, we found significantly higher (although marginal) rates of genetic exchange between strains expressing different pherotypes than among isolates carrying the same pherotype. Our results indicate that pherotypes do not restrict, and may even slightly facilitate, recombination between strains; however, these marginal effects suggest the more likely possibility that the cause of CSP polymorphism lies outside of its effects on transformation. Our results suggest that the CSP balanced polymorphism does not causally underlie population differentiation. Therefore, when strains carrying different pherotypes encounter one another during cocolonization, genetic exchange can occur without restriction

    Cerebrospinal fluid shunting for the management of cryptococcal meningitis: a scoping review

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    Objective: This scoping review aimed to describe studies that evaluate the management of cryptococcal meningitis (CM) using cerebrospinal fluid (CSF) shunts, types of shunts used, and clinically relevant patient outcomes. Methods: We searched in the following databases: PubMed, Web of Science/Core collection, Embase, the Cochrane Library, and clinicaltrials.gov on 1 April 2022. We included two-arm and one-arm cohort studies that evaluated clinically relevant patient outcomes. Case reports were used to describe the type of CSF shunts used and the rationale behind its selection. The selection and extraction processes were independently performed by two authors. Results: This study included 20 cohort studies and 26 case reports. Only seven cohort studies compared two groups. Ventriculoperitoneal shunt was the most commonly used type of shunt (82.1%). The main indications for placing a shunt were persistently high opening pressure (57.1%) and persisting neurological symptoms or deterioration (54.3%). Cohort studies suggest that patients with shunt showed improvement in some outcomes such as neurological symptoms and hospital stay length. The most common shunt complications were post-operative fever (1–35.6%) and shunt obstruction (7–16%). Conclusion: CSF shunts may improve some clinically relevant outcomes in patients with CM, but the evidence is very uncertain.Revisión por pare

    Percepción de estudiantes, sobre las implicancias éticas de las prácticas clínicas odontológicas durante su formación de grado

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    El odontólogo como profesional de la salud, para responder en forma integral a las necesidades sociales, debe disponer, no sólo de “un saber saber” y un “saber hacer”, sino también de un "saber ser", en el desempeño profesional. La formación universitaria aporta al desarrollo moral en el que se afianza la práctica profesional. El presente trabajo tuvo como objetivo conocer la percepción de estudiantes, sobre las implicancias éticas de las prácticas clínicas odontológicas durante su formación de grado. Desde un abordaje cualitativo se indagó sobre situaciones o experiencias vivenciadas por estudiantes durante el trayecto formativo de la práctica clínica odontológica, en que se hayan planteado conflictos o dilemas éticos y aspectos relacionados Se realizaron entrevistas en profundidad a estudiantes que durante 2018, cursaban el ciclo profesional de la carrera de odontología de la UNC. El análisis de la información realizado por el método comparativo constante, puso en evidencia que durante algunas prácticas clínicas se presentan situaciones de implicancia ética, que se resuelven frecuentemente, sin sustento teórico ni metodológico, de manera fortuita priorizando la exigencia académica. La capacitación docente en el área de bioética, podría fortalecer una formación más reflexiva e integral, que incluya competencias para tomar decisiones basadas en saberes éticosEspecialización en Docencia Universitari

    Neck circumference and clustered cardiovascular risk factors in children and adolescents: Cross-sectional study

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    Objective Early detection of cardiovascular disease (CVD) risk factors, such as obesity, is crucial to prevent adverse long-term effects on individuals'' health. Therefore, the aims were: (1) to explore the robustness of neck circumference (NC) as a predictor of CVD and examine its association with numerous anthropometric and body composition indices and (2) to release sex and age-specific NC cut-off values to classify youths as overweight/obese. Design Cross-sectional study. Setting 23 primary schools and 17 secondary schools from Spain. Participants 2198 students (1060 girls), grades 1-4 and 7-10. Measures Pubertal development, anthropometric and body composition indices, systolic and diastolic blood pressure (SBP and DBP, respectively), cardiorespiratory fitness, blood sampling triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), glucose and inflammatory markers. Homoeostasis model assessment (HOMA-IR) and cluster of CVD risk factors were calculated. Results NC was positively correlated with all anthropometric and body composition indices. NC was negatively associated with maximum oxygen consumption (R 2 =0.231, p<0.001 for boys; R 2 =0.018, p<0.001 for girls) and positively associated with SBP, DBP, TC/HDL-c, TG, HOMA, complement factors C-3 and C-4, leptin, adiponectin and clustered CVD risk factor in both sexes (R 2 from 0.035 to 0.353, p<0.01 for boys; R 2 from 0.024 to 0.215, p<0.001 for girls). Moreover, NC was positively associated with serum C reactive protein, LDL-c and visfatin only in boys (R 2 from 0.013 to 0.107, p<0.05). Conclusion NC is a simple, low-cost and practical screening tool of excess of upper body obesity and CVD risk factors in children and adolescents. Paediatricians can easily use it as a screening tool for overweight/obesity in children and adolescents. For this purpose, sex and age-specific thresholds to classify children and adolescents as normal weight or overweight/obese are provided

    Precision Electron-Beam Polarimetry using Compton Scattering at 1 GeV

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    We report on the highest precision yet achieved in the measurement of the polarization of a low energy, O\mathcal{O}(1 GeV), electron beam, accomplished using a new polarimeter based on electron-photon scattering, in Hall~C at Jefferson Lab. A number of technical innovations were necessary, including a novel method for precise control of the laser polarization in a cavity and a novel diamond micro-strip detector which was able to capture most of the spectrum of scattered electrons. The data analysis technique exploited track finding, the high granularity of the detector and its large acceptance. The polarization of the 180 μ180~\muA, 1.161.16~GeV electron beam was measured with a statistical precision of <<~1\% per hour and a systematic uncertainty of 0.59\%. This exceeds the level of precision required by the \qweak experiment, a measurement of the vector weak charge of the proton. Proposed future low-energy experiments require polarization uncertainty <<~0.4\%, and this result represents an important demonstration of that possibility. This measurement is also the first use of diamond detectors for particle tracking in an experiment.Comment: 9 pages, 7 figures, published in PR

    Climate drives fire synchrony but local factors control fire regime change in northern Mexico

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    The occurrence of wildfire is influenced by a suite of factors ranging from “top-down” influences (e.g., climate) to “bottom-up” localized influences (e.g., ignitions, fuels, and land use). We carried out the first broad-scale assessment of wildland fire patterns in northern Mexico to assess the relative influence of top-down and bottom-up drivers of fire in a region where frequent fire regimes continued well into the 20th century. Using a network of 67 sites, we assessed (1) fire synchrony and the scales at which synchrony is evident, (2) climate drivers of fire, and (3) asynchrony in fire regime changes. We found high fire synchrony across northern Mexico between 1750 and 2008, with synchrony highest at distances oscillations, especially El Niño-Southern Oscillation, were important drivers of fire synchrony. However, bottom-up factors modified fire occurrence at smaller spatial scales, with variable local influence on the timing of abrupt, unusually long fire-free periods starting between 1887 and 1979 CE. Thirty sites lacked these fire-free periods. In contrast to the neighboring southwestern United States, many ecosystems in northern Mexico maintain frequent fire regimes and intact fire–climate relationships that are useful in understanding climate influences on disturbance across scales of space and time

    Testing for Complementarity: Glyphosate Tolerant Soybeans and Conservation Tillage

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    Many decisions in agriculture are made over combinations of inputs and/or practices that may form a technology system linked through complementarity. The presence of complementarity among producer decisions can have far-reaching implications for market outcomes and for the effectiveness of policies intended to influence them. Identifying complementarity relations, however, is made difficult by the presence of unobserved heterogeneity. Drawing on recent methodological advances, in this paper we develop a test for complementarity between glyphosate tolerant soybeans and conservation tillage that overcomes certain limitations of previous studies. Specifically, we develop a structural discrete choice framework of joint soybean-tillage adoption that explicitly models both complementarity and the correlation induced by unobserved heterogeneity. The model is estimated with a large unbalanced panel of farm-level choices spanning the 1998–2011 period. We find that glyphosate tolerant soybeans and conservation tillage are complementary practices. In addition, our estimation shows that farm operation scale promotes the adoption of both conservation tillage and glyphosate tolerant seed, and that all of higher fuel prices, more droughty conditions, and soil erodibility increase use of conservation tillage. We apply our results to simulate annual adoption rates for both conservation tillage and no-tillage in a scenario without glyphosate tolerant soybeans available as a choice. We find that the adoption of conservation tillage and no-tillage have been about 10% and 20% higher, respectively, due to the advent of glyphosate tolerant soybeans
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