198 research outputs found

    Modelagem matemática da dinâmica temporal do HLB.

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    RESUMO: O Huanglongbing (HLB) e considerado atualmente a mais grave doença da citricultura nacional, devido aos enormes prejuízos econômicos que pode causar. Este trabalho apresenta um modelo matemático epidemiológico para avaliar a evolução temporal da doença considerando o sistema planta (citros) - inseto vetor (Diaphorina citri). Com base na literatura determinou-se faixas de variacao para os parâmetros biológicos do modelo. A partir da criação de cenários de simulação verificou-se numericamente algumas condições que favorecem a evolução da doença.SBIAgro 2011

    A Cellular Automata Model for Citrus Variagated Chlorosis

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    A cellular automata model is proposed to analyze the progress of Citrus Variegated Chlorosis epidemics in S\~ao Paulo oranges plantation. In this model epidemiological and environmental features, such as motility of sharpshooter vectors which perform L\'evy flights, hydric and nutritional level of plant stress and seasonal climatic effects, are included. The observed epidemics data were quantitatively reproduced by the proposed model varying the parameters controlling vectors motility, plant stress and initial population of diseased plants.Comment: 10 pages, 10 figures, Scheduled tentatively for the issue of: 01Nov0

    Effect of the displacement rate and inclination angle in steel fiber pullout tests

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    This paper summarizes the results obtained in an experimental campaign on the effect of the displacement pullout rate and the inclination angle of the steel fiber pullout tests. For that purpose, specimens were obtained from a self-compacting concrete with a compressive strength of 86 MPa. In the experimental program, hooked-end steel fibers of 0.75 mm diameter and 60 mm length were used. Tests were executed with both hooked-end fibers, and smooth fibers obtained from the former by cutting the hooked end. For both type of fibers, their embedment length into concrete was 20 mm, and the influence of fiber inclination angle toward the load direction was investigated by adopting values of 0∘, 30∘ and 60∘. The tests were performed at displacement rates of 0.01, 0.1 and 1 mm/s. The results have shown that the peak pullout load increased with the inclination angle, in particular for the smooth series. Furthermore, higher displacement rates led to a higher energy absorption capacity for the pullout of the smooth fibers, while the energy absorption remained almost stable for hooked-end fibers.project BIA2015-68678-C2-1-R. M. Tarifa appreciates the financial support from the Department of Applied Mechanics and Project Engineering, UCLM (2018), and from the Programa propio de I+D+i de la Universidad Politécnica de Madrid para realizar estancias de investigación internacional igual o superior a un mes (2019), to do two stays at the University of Minho, Guimarães, Portugal. E. Poveda acknowledges the funding from the International Campus of Excellence CYTEMA and the University of Castilla-La Mancha, throughout Ayudas para estancias en universidades y centros de investigación en el extranjero en 2019 en el ámbito del plan propio de investigación susceptibles de cofinanciación por el Fondo Europeo de Desarrollo Regional (FEDER), Programa 010100021 to fund her stays in the University of Minho during 2018 and 2019, respectively. The authors thank the support of the Department of Civil Engineering and the Laboratory of the Structural Division (LEST), University of Minh

    Intervencoes Psicossociais para Promocao da Saude do Homen em Unidade de Saude da Familia = Psychosocial interventions to promote Men's Health in Family Health Centers = Intervenciones Psicosociales para la Promocion de la Salud del Hombre en Centros de Salud de la Familia

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    This study on professional experience aims to contribute insights to answer the question, how can we promote men's health in Primary Health Care (PHC)? We describe two health interventions implemented in a Family Health Center, FHC (Brazilian PHC main facility), in Vitória, Brazil: the "Saturday Health Actions" and the "Group of Men." Each "Saturday Health Action" occurs every three months on a Saturday morning, lasts for four hours, and includes recreational activities and health education sessions (for example, discussions about sexually transmitted diseases). The "Group of Men" occurs weekly, lasts only for 1 h 15 min, and includes health education sessions (for example, discussions about alcohol problems) and psychotherapeutic workshops. Between September 2011 and July 2013, the interventions approached around 230 men from lower social classes. The concepts of comprehensive clinic and psychotherapeutic attitude are used to encourage the subjective expression of participants and their co-responsibility with the health-sickness process. Among the results, we highlight the increase in the participation of male patients in the FHC, the improvement of care delivered to chronic conditions (especially hypertension, diabetes, and alcohol problems/alcoholism), and the strengthening of harm reduction behaviors. We conclude that the interventions reported are useful in dealing with challenges related to Men's Health

    Standardized and reproducible measurement of decision-making in mice

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    Progress in science requires standardized assays whose results can be readily shared, compared, and reproduced across laboratories. Reproducibility, however, has been a concern in neuroscience, particularly for measurements of mouse behavior. Here we show that a standardized task to probe decision-making in mice produces reproducible results across multiple laboratories. We designed a task for head-fixed mice that combines established assays of perceptual and value-based decision making, and we standardized training protocol and experimental hardware, software, and procedures. We trained 140 mice across seven laboratories in three countries, and we collected 5 million mouse choices into a publicly available database. Learning speed was variable across mice and laboratories, but once training was complete there were no significant differences in behavior across laboratories. Mice in different laboratories adopted similar reliance on visual stimuli, on past successes and failures, and on estimates of stimulus prior probability to guide their choices. These results reveal that a complex mouse behavior can be successfully reproduced across multiple laboratories. They establish a standard for reproducible rodent behavior, and provide an unprecedented dataset and open-access tools to study decision-making in mice. More generally, they indicate a path towards achieving reproducibility in neuroscience through collaborative open-science approaches

    An Organic Spin Crossover Material in Water from a Covalently Linked Radical Dyad

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    A covalently linked viologen radical cation dyad acts as a reversible thermomagnetic switch in water. Cycling between diamagnetic and paramagnetic forms by heating and cooling is accompanied by changes in optical and magnetic properties with high radical fidelity. Thermomagnetic switches in water may eventually find use as novel biological thermometers and in temperature-responsive organic materials where the changes in properties originate from a change in electronic spin configuration rather than a change in structure

    Reaching the Hard-to-Reach: A Probability Sampling Method for Assessing Prevalence of Driving under the Influence after Drinking in Alcohol Outlets

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    Drinking alcoholic beverages in places such as bars and clubs may be associated with harmful consequences such as violence and impaired driving. However, methods for obtaining probabilistic samples of drivers who drink at these places remain a challenge – since there is no a priori information on this mobile population – and must be continually improved. This paper describes the procedures adopted in the selection of a population-based sample of drivers who drank at alcohol selling outlets in Porto Alegre, Brazil, which we used to estimate the prevalence of intention to drive under the influence of alcohol. The sampling strategy comprises a stratified three-stage cluster sampling: 1) census enumeration areas (CEA) were stratified by alcohol outlets (AO) density and sampled with probability proportional to the number of AOs in each CEA; 2) combinations of outlets and shifts (COS) were stratified by prevalence of alcohol-related traffic crashes and sampled with probability proportional to their squared duration in hours; and, 3) drivers who drank at the selected COS were stratified by their intention to drive and sampled using inverse sampling. Sample weights were calibrated using a post-stratification estimator. 3,118 individuals were approached and 683 drivers interviewed, leading to an estimate that 56.3% (SE = 3,5%) of the drivers intended to drive after drinking in less than one hour after the interview. Prevalence was also estimated by sex and broad age groups. The combined use of stratification and inverse sampling enabled a good trade-off between resource and time allocation, while preserving the ability to generalize the findings. The current strategy can be viewed as a step forward in the efforts to improve surveys and estimation for hard-to-reach, mobile populations
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