953 resultados para Recent Positive Selection
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The silvopastoral system is a viable technological alternative to extensive cattle grazing, however, for it to be successful, forage grass genotypes adapted to reduced light need to be identified. The objective of this study was to select progenies of Panicum maximum tolerant to low light conditions for use in breeding programs and to study the genetic control and performance of some traits associated with shade tolerance. Six full-sib progenies were evaluated in full sun, 50% and 70% of light reduction in pots and subjected to cuttings. Progeny genotypic values (GV) increased with light reduction in relation to plant height (H) and specific leaf area (SLA). The traits total dry mass accumulation (DM) and leaf dry mass accumulation (LDM) had GV higher in 50% shade and intermediate in 70% shade. The GV of tiller number (TIL) and root dry mass accumulation (RDM) decreased with light reduction. The highest positive correlations were obtained for the traits H and RDM with SLA and DM; the highest negative correlations were between TIL and SLA and RDM, and H and LDM. The progenies showed higher tolerance to 50% light reduction and, among them, two stood out and will be used in breeding programs. It was also found that it is not necessary to evaluate some traits under all light conditions. All traits had high broad sense heritability and high genotypic correlation between progenies in all light intensities. There is genetic difference among the progenies regarding the response to different light intensities, which will allow selection for shade tolerance
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Electrocardiography (ECG) biometrics is emerging as a viable biometric trait. Recent developments at the sensor level have shown the feasibility of performing signal acquisition at the fingers and hand palms, using one-lead sensor technology and dry electrodes. These new locations lead to ECG signals with lower signal to noise ratio and more prone to noise artifacts; the heart rate variability is another of the major challenges of this biometric trait. In this paper we propose a novel approach to ECG biometrics, with the purpose of reducing the computational complexity and increasing the robustness of the recognition process enabling the fusion of information across sessions. Our approach is based on clustering, grouping individual heartbeats based on their morphology. We study several methods to perform automatic template selection and account for variations observed in a person's biometric data. This approach allows the identification of different template groupings, taking into account the heart rate variability, and the removal of outliers due to noise artifacts. Experimental evaluation on real world data demonstrates the advantages of our approach.
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RESUMO - Com tanto ruído informativo e peças de informação incompletas e descontextualizadas, relativos ao controlo da tuberculose em Portugal, a chegarem ao cidadão e aos profissionais de saúde, não é fácil que eles disponham do conhecimento necessário ao desempenho dos respectivos papéis nesse controlo. O presente artigo pretende contribuir para um ganho real em conhecimento quanto (1) ao progresso no controlo da tuberculose em Portugal, enquadrado na evolução desse controlo noutras regiões pertinentes, e (2) aos aspectos do conhecimento disponível e da intervenção na população portuguesa que suscitem especial atenção, para melhoria no futuro imediato. Tem como estratégia integrar, e elevar ao nível de conhecimento, a informação disponibilizada nas fontes mais credíveis e pertinentes, valorizada no contexto da validade das mesmas fontes e da coerência dos diversos componentes. Relata o resultado de um exercício independente de apreciação crítica, com uma perspectiva epidemiológica. São observados: a situação actual, sobretudo a relativa aos anos de 2006 e 2007, e o desempenho do Programa Nacional de Controlo da Tuberculose (PNT), ambos relativizados à evolução recente e ao panorama internacional. O exercício de observação e revisão independentes baseia-se numa selecção de informação oficial e segue o mesmo método de abordagem que a O.M.S. faz nos seus relatórios anuais, à semelhança de outros exercícios já antes realizados. O controlo da tuberculose tem prosseguido a sua tímida, mas firme, evolução favorável, aproximando-se do nível já conseguido nos países seus vizinhos da Europa Ocidental. Em 2007, Portugal contribuiu para os 9 milhões de casos novos anuais, estimados no mundo, com 2916 casos notificados. A este número corresponde a taxa de incidência notificada de 25,7 por 100 000 habitantes e uma redução de 14% em relação ao ano anterior. Esta evolução afigura-se animadora, ainda que seja desejável um impacte mais acentuado do PNT, conforme é de esperar considerando o grau de desenvolvimento do País. A taxa de detecção de casos novos estimada é elevada e continua uma das melhores da Europa Ocidental — o que desfavorece artificialmente a imagem notificada do País, relativamente aos países com pior capacidade de detecção. A taxa de sucesso terapêutico melhorou de novo, situando- -se acima da meta de 85% preconizada pela O.M.S, para um bom controlo da tuberculose. Uma das consequências importantes é que se consegue um melhor aproveitamento da detecção habitualmente alcançada. O conhecimento no seu conjunto aponta para que o grau de controlo possa e deva realmente ser melhorado, sendo imperiosa a discriminação positiva das áreas geográficas e dos grupos populacionais em que tende a concentrar-se a emergência de maior número de casos e de resistências aos medicamentos. Deverão assim ser reforçados selectivamente tanto os meios de detecção e de intervenção clínica, como a qualidade da organização local da intervenção, para o cumprimento efectivo da estratégia DOTS. Enquanto programa vertical que atravessa os diversos níveis do sistema de cuidados de saúde, o desempenho do PNT sofre os efeitos das atribulações desses serviços, sobretudo os de cuidados primários, funcionando como uma «situação-marcadora» quanto ao desempenho do sistema de saúde. A evidência é de que é nesta primeira linha de cuidados que se decide o sucesso na detecção e no tratamento dos casos de tuberculose, reflectindo-se também aí o grau de desenvolvimento social e os comportamentos das populações, por sua vez determinantes do risco de doença e do sucesso terapêutico. ------------------- ABSTRACT - It is not easy that both the citizen and health professionals get enabled with the required knowledge, in order do play the corresponding roles in the control of tuberculosis, considering all the information noise and incomplete, out of context information pieces about the subject, that reach them. This paper is envisaging to contribute for a real gain in knowledge, regarding: (1) the progress in tuberculosis control in Portugal, framed by the evolution of such control in other pertinent regions and (2) the available knowledge and intervention aspects in the Portuguese population that require a special attention, for improvement. The article’s strategy is to integrate, and raise to a knowledge level, information provided by the most accredited and pertinent sources, interpreted as a function of the validity context of the same sources and of the coherence of the several components. Two aspects are observed: the current situation, in particular concerning years 2006 and 2007, and the performance of the National Programme for the Tuberculosis Control (PNT), both made relative to the recent evolution and to the international panorama. This independent observation and revision exercise is based on a selection of official information and follows the same approach that the World Health Organization (W.H.O.) uses in its annual reports, like other similar exercises previously undertaken. The control of tuberculosis is evolving in a shy, but firm, fashion, getting closer to the level already attained by the neighbor countries, in Western Europe. Portugal has contributed with 2916 new notified cases, to the 9 million annual cases estimated in the world, in 2007. This number corresponds to an incidence rate, for notified cases, of 25.7 per 100000 population, and to a reduction of 14% in one year. Such evolution seems encouraging, although a greater impact of PNT is desirable, as expected in relation to the degree of the Country development. Estimated new cases detection rate is high and keeps being one of the best in Western Europe — and this artificially disadvantages the notified image of the Country, as compared with other countries having a worst detection capacity. Treatment success rate has improved again and it is above the 85% target proposed by W.H.O., so that a good control of the disease is achieved. One of the important consequences is a better use of the attained detection. Altogether, knowledge suggests that the degree of control can and must be in fact better; and that a positive discrimination of geographic areas and population groups, in which a greater number of new cases and drug resistances tend to concentrate, is mandatory. Therefore, either clinical detection and intervention resources, or the quality of the local intervention organization have to be reinforced, if a total fulfillment of DOTS strategy is to be obtained. As a vertical programme that crosses the several levels of the health care system, PNT performance suffers the effects of services tribulations, mainly primary care, thus acting as a «markersituation » as to this system performance. Evidence shows that it is in this first line of care that success in both detection and treatment of tuberculosis cases is decided; and that this level also reveals the degree of social developmen
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SUMMARY Background. Disseminated histoplasmosis is common in AIDS patients with advanced immunosuppression in Ceará, Northeastern Brazil. The goal of this study was to determine the prevalence of Histoplasma infection in patients with HIV/AIDS living in Fortaleza, the capital of Ceará. Methods. Intradermal tests with histoplasmin (mycelial phase) were performed in 161 HIV patients with CD4 ≥ 350 cells/mm 3 . Evidence of recent illness was evaluated with immunodiffusion (ID) tests in 76 of these individuals. Results. A total of 11.8% of patients reacted to histoplasmin and 2.63% had ID test positive to Histoplasma. The presence of mango trees (Mangifera indica) in the patient neighborhood (OR = 2.870; 95% CI = 1.081-7.617; p = 0.040) and past activity involving soil (OR = 2.834; 95% CI = 1.045-7.687; p = 0.045) or visits to a farm (OR = 3.869; 95% CI = 1.189-12.591; p = 0.033) were significantly associated with Histoplasma infection. Conclusions. Patients with HIV living in Fortaleza have an expressive prevalence of infection with Histoplasma.
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Dissertation presented to obtain the Ph.D degree in Biology
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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
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Introduction Despite the great advances in serological testing for transfusion-transmitted infections, the selection of blood donors by blood bank operators remains the only way to avoid transmission within the testing window period. Part of this selection is the self-exclusion form, on which the donors can exclude their blood from donation without any explanation. This study assessed the clinical and epidemiological characteristics related to positivity for viral hepatitis and to the use of the confidential self-exclusion (CSE) form. Methods This transversal study analyzed the data collected from blood donors' files in a hospital in Southern Brazil. Univariate and multivariate analyses identified the clinical and epidemiological variables related to positive serologies of viral hepatitis and to whether the donor was self-excluded. Results Of the 3,180 donors included in this study, 0.1% tested positive for HBsAg, 2.1% for anti-HBc, and 0.9% for anti-HCV. When the 93 donors with positive serologies for viral hepatitis were compared with those who were negative, a greater proportion of the positive serology group was found to have had a history of blood transfusions (OR=4.908; 95%CI=1.628 - 14.799; p<0.01), had repeatedly donated (OR=2.147; 95%CI=1.236 - 3.729; p<0.01), and used the CSE form for self-exclusion (OR=7.139; 95%CI=2.045 - 24.923; p<0.01). No variables were independently associated with self-exclusion. Conclusions A history of blood transfusion, repeated donations, and self-exclusion are factors that should be considered during viral hepatitis screenings in blood banks.
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AbstractPhage display is a high-throughput subtractive proteomic technology used for the generation and screening of large peptide and antibody libraries. It is based on the selection of phage-fused surface-exposed peptides that recognize specific ligands and demonstrate desired functionality for diagnostic and therapeutic purposes. Phage display has provided unmatched tools for controlling viral, bacterial, fungal, and parasitic infections, and allowed identification of new therapeutic targets to treat cancer, metabolic diseases, and other chronic conditions. This review presents recent advancements in serodiagnostics and prevention of leishmaniasis -an important tropical parasitic disease- achieved using phage display for the identification of novel antigens with improved sensitivity and specificity. Our focus is on theranostics of visceral leishmaniasis with the aim to develop biomarker candidates exhibiting both diagnostic and therapeutic potential to fight this important, yet neglected, tropical disease.
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Novel input modalities such as touch, tangibles or gestures try to exploit human's innate skills rather than imposing new learning processes. However, despite the recent boom of different natural interaction paradigms, it hasn't been systematically evaluated how these interfaces influence a user's performance or whether each interface could be more or less appropriate when it comes to: 1) different age groups; and 2) different basic operations, as data selection, insertion or manipulation. This work presents the first step of an exploratory evaluation about whether or not the users' performance is indeed influenced by the different interfaces. The key point is to understand how different interaction paradigms affect specific target-audiences (children, adults and older adults) when dealing with a selection task. 60 participants took part in this study to assess how different interfaces may influence the interaction of specific groups of users with regard to their age. Four input modalities were used to perform a selection task and the methodology was based on usability testing (speed, accuracy and user preference). The study suggests a statistically significant difference between mean selection times for each group of users, and also raises new issues regarding the “old” mouse input versus the “new” input modalities.
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Modeling clays have been used in several ecological experiments and have proved to be an important tool to variables control. The objective of our study was to determine if fruit color in isolated and grouped displays influences the fruit selection by birds in the field using artificial fruits. Data were collected in six plots distributed homogeneously in 3 km long trails with a minimum distance of 0.5 km. We used a paired experimental design to establish our experiments, so that all treatments were available to the local bird community in each plot. Overall, red was more pecked than brown and white. Isolated red and brown displays were significantly more pecked than others display. Even though our study was conducted in small spatial scales, artificial fruits appeared to be efficient in register fruit consumption attempts by bird. Although inconclusive about selective forces that sharp the dynamics of fruit color polymorphisms and choice by frugivorous birds, our findings corroborate recent studies wherein birds showed preferences by high- over low-contrast fruit signals.
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Dissertação de mestrado Internacional em Sustentabilidade do Ambiente Construído
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Statin treatment in association with physical exercise practice can substantially reduce cardiovascular mortality risk of dyslipidemic individuals, but this practice is associated with myopathic event exacerbation. This study aimed to present the most recent results of specific literature about the effects of statins and its association with physical exercise on skeletal musculature. Thus, a literature review was performed using PubMed and SciELO databases, through the combination of the keywords “statin” AND “exercise” AND “muscle”, restricting the selection to original studies published between January 1990 and November 2013. Sixteen studies evaluating the effects of statins in association with acute or chronic exercises on skeletal muscle were analyzed. Study results indicate that athletes using statins can experience deleterious effects on skeletal muscle, as the exacerbation of skeletal muscle injuries are more frequent with intense training or acute eccentric and strenuous exercises. Moderate physical training, in turn, when associated to statins does not increase creatine kinase levels or pain reports, but improves muscle and metabolic functions as a consequence of training. Therefore, it is suggested that dyslipidemic patients undergoing statin treatment should be exposed to moderate aerobic training in combination to resistance exercises three times a week, and the provision of physical training prior to drug administration is desirable, whenever possible.
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This comment corrects the errors in the estimation process that appear in Martins (2001). The first error is in the parametric probit estimation, as the previously presented results do not maximize the log-likelihood function. In the global maximum more variables become significant. As for the semiparametric estimation method, the kernel function used in Martins (2001) can take on both positive and negative values, which implies that the participation probability estimates may be outside the interval [0,1]. We have solved the problem by applying local smoothing in the kernel estimation, as suggested by Klein and Spady (1993).