865 research outputs found

    Eye evolution simulation with a genetic algorithm based on the hypothesis of Nilsson and Pelger

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    The present work addresses for the first time the simulation of the evolution of an elemental eye by means of a simple genetic algorithm. The problem of the gradual evolution of a structure as complex as the eye was raised by Darwin, being still at the beginning of the 21st century a source of controversy between creationists and evolutionists. Taking as a starting point the paper of Nilsson and Pelger and their hypothesis that the evolution of the eye can be studied if we limit ourselves to its optical geometry, we show how eye evolution could take place gradually applying the principle of natural selection. Our model is limited to studying how an array of photosensitive epithelial cells is bent gradually to achieve a camera obscura

    Convolution Neural Network Models for Acute Leukemia Diagnosis

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    Acute leukemia is a cancer-related to a bone marrow abnormality. It is more common in children and young adults. This type of leukemia generates unusual cell growth in a short period, requiring a quick start of treatment. Acute Lymphoid Leukemia (ALL) and Acute Myeloid Leukemia (AML) are the main responsible for deaths caused by this cancer. The classification of these two leukemia types on blood slide images is a vital process of and automatic system that can assist doctors in the selection of appropriate treatment. This work presents a convolutional neural networks (CNNs) architecture capable of differentiating blood slides with ALL, AML and Healthy Blood Slides (HBS). The experiments were performed using 16 datasets with 2,415 images, and the accuracy of 97.18% and a precision of 97.23% were achieved. The proposed model results were compared with the results obtained by the state of the art methods, including also based on CNNs. (c) 2020 IEEE

    Efficacy of proteolytic enzyme bromelain on health outcomes after third molar surgery. Systematic review and meta-analysis of randomized clinical trials

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    Bromelain is a cysteine protease isolated from pineapple with a range of biological properties including platelet aggregation inhibition and anti-inflammatory effects. Recent studies have evaluated the clinical implications of bromelain in reducing postoperative inflammatory complications after third molar surgery, but the results are contrasting. This systematic review and meta-analysis evaluated the effects of bromelain on health outcomes in patients submitted to third molar surgery. The study was conducted following the PRISMA statement. Searches were conducted in six electronic databases and Google Scholar from inception to May 2018. The following elements were used to define eligibility criteria: (1) population: patients undergoing third molar surgery; (2) intervention and controls: bromelain vs placebo or no-treatment control group; (3) outcomes: quality of life, postoperative pain, rescue analgesic consumption, facial swelling, and trismus; and (4) study type: randomized clinical trials (RCTs). Treatment effects were defined as weighted (WMD) or standardized mean difference (SMD) and 95%CIs. Six RCTs were included in the meta-analysis. There was large effect size of bromelain on improving physical appearance (SMD -0.77, CI% 95 -1.11 to -0.42), social isolation (SMD -0.97, CI% 95 -1.74 to -0.21), and sleep quality (SMD -1.19, CI% 95 -1.97 to -0.40) during the first postoperative week. Differences in pain intensity were found during the first 24h (SMD -0.49, CI 95% -0.82 to -0.17) and 7 days after surgery (SMD -0.52, CI 95% -0.79 to -0.24). No evidence was found that bromelain was effective in reducing trismus and facial swelling. The currently available evidence suggests that bromelain has a beneficial effect in reducing pain and has a positive impact on patient quality of life after third molar surgery. However, therapeutic advances for the use of bromelain need a high level of evidence and further head-to-head RCTs are needed to inform clinical choices

    Neuroinfection survey at a neurological ward in a Brazilian tertiary teaching hospital

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    OBJECTIVES: This study was undertaken to characterize the neuroinfection profile in a tertiary neurological ward. INTRODUCTION: Neuroinfection is a worldwide concern and bacterial meningitis, tetanus and cerebral malaria have been reported as the commonest causes in developing countries. METHODS: From 1999 to 2007, all patients admitted to the Neurology Ward of Hospital das Clínicas, São Paulo University School of Medicine because of neuroinfection had their medical records reviewed. Age, gender, immunological status, neurological syndrome at presentation, infectious agent and clinical outcome were recorded. RESULTS: Three hundred and seventy four cases of neuroinfectious diseases accounted for 4.2% of ward admissions and the identification of infectious agent was successful in 81% of cases. Mean age was 40.5 + 13.4 years, 63.8% were male, 19.7% were immunocompromised patients and meningoencephalitis was the most common clinical presentation despite infectious agent. Viruses and bacteria were equally responsible for 29.4% of neuroinfectious diseases; parasitic, fungal and prion infections accounted for 28%, 9.6% and 3.5% respectively. Human immunodeficiency virus (HIV), herpes simplex virus 1 (HSV1), Mycobacterium tuberculosis, Treponema pallidum, Taenia solium, Schistosoma mansoni, Cryptococcus neoformans and Histoplasma capsulatum were the more common infectious pathogens in the patients. Infection mortality rate was 14.2%, of which 62.3% occurred in immunocompetent patients. CONCLUSION: Our institution appeared to share some results with developed and developing countries. Comparison with literature may be considered as quality control to health assistance

    Is anodal transcranial direct current stimulation a potential ergogenic resource for muscle strength and effort perception? A critical review

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    Nas últimas décadas, vários estudos estão investigando a dose-resposta ideal em termos de frequência, intensidade e volume de treinamento para alcançar o aumento da força muscular, tanto em atletas quanto em não atletas. A dose-resposta é fundamental para a prescrição do treinamento, uma vez que sua manipulação equivocada pode acarretar alto risco de desenvolvimento de lesões por esforços repetitivos, bem como pelo não desenvolvimento da força esperada. Em indivíduos com nível avançado de treinamento de força, é extremamente importante aumentar sua intensidade e volume de treinamento. Nesse sentido, com os avanços encontrados na área de treinamento de força e a necessidade de novas estratégias para otimizar ganhos de força, um novo método vem ganhando força na literatura, a estimulação transcraniana por corrente contínua (ETCC). Portanto, o objetivo deste estudo é analisar criticamente os efeitos do ETCC como potencial recurso ergogênico para a realização de força muscular e percepção de esforço, bem como se seu uso é ético ou não. Para tanto, foram pesquisadas as bases de dados Pubmed/Medline, ISI Web of Knowledge e Scielo, apenas em inglês, e com as palavras-chave: força muscular, resistência muscular, estimulação transcraniana por corrente contínua, ETCC. Nós comparamos o efeito do ETCC anódico (ETCC-a) com uma condição sham/controle nos resultados de ETCC para força muscular e percepção de esforço força muscular e percepção de esforço. Nenhum estudo menciona efeitos colaterais negativos da intervenção. Os dados mostram diferenças entre os estudos que investigam os estudos de avaliação da força muscular e resistência muscular, em termos do uso bem sucedido de ETCC. Estudos que investigaram a eficiência do ETCC na melhora da força muscular demonstraram efeitos positivos do ETCC-a em 66,7% dos parâmetros testados. Amaioria dos dados mostra consistentemente a influência do ETCC-a na força muscular, mas não no desempenho de resistênciaEn las últimas décadas, diversos estudios están investigando la dosis-respuesta ideal en cuanto a la frecuencia, intensidad y volumen de entrenamiento para alcanzar el aumento de fuerza muscular, sea en atletas y no atletas. La dosis-respuesta es fundamental para la prescripción de entrenamiento, pues su manipulación equivocada puede llevar a un alto de riesgo de desarrollo de lesiones por esfuerzo repetitivo, así como para el no desarrollo de la fuerza esperada. En sujetos con nivel avanzado de entrenamiento de fuerza es extremadamente importante aumentar su intensidad y volumen de entrenamiento. En este sentido, con los avances encontrados en el área de entrenamiento de fuerza y la necesidad de nuevas estrategias para optimizar las ganancias de fuerza, un nuevo método está ganando fuerza en la literatura, la estimulación transcraneal por corriente continua (ETCC). Por lo tanto, el objetivo del presente estudio es analizar de forma crítica los efectos de la ETCC como potencial recurso ergogénico al desempeño de fuerza muscular y percepción de esfuerzo, así como si su uso es ético o no. Por lo tanto, se realizó una búsqueda en las bases de datos Pubmed/Medline, ISI Web of Knowledge y Scielo, solamente en inglés y con las palabras clave: fuerza muscular, resistencia muscular, estimulación transcraneal de corriente continua, ETCC. Comparamos el efecto de la ETCC anódica (ETCC-a) a una condición sham/control sobre los resultados de la fuerza muscular y percepción de esfuerzo. Ningún estudio menciona efectos secundarios negativos de la intervención. Los datos muestran diferencias entre los estudios que investigan la fuerza muscular y los estudios de evaluación de resistencia muscular, en lo que se refiere al uso exitoso de la ETCC. Los estudios que investigan la eficiencia de la ETCC en la mejora de la fuerza muscular demuestran efectos positivos de la ETCC-a en el 66,7% de los parámetros probados. La mayoría de los datos muestran consistentemente influencia de la ETCC-a en la fuerza muscular, pero no en el rendimiento de resistencia.In the last decades, several studies are investigating the optimal dose-response in terms of frequency, intensity and volume of training to achieve increased muscle strength in both athletes and non-athletes. Dose-response is critical to the prescription of training, since its mismanagement may pose a high risk of developing repetitive strain injuries as well as failure to develop the expected strength. In individuals with advanced level of strength training, it is extremely important to increase their intensity and training volume. In this sense, with the advances in the area of strength training and the need for new strategies to optimize force gains, a new method is gaining strength in the literature, the transcranial direct current stimulation (tDCS). Therefore, the purpose of this study is to critically analyze the effects of tDCS as a potential ergogenic resource for achieving muscle strength and perceived exertion, as well as whether its use is ethical or not. To do so, we searched the databases Pubmed/Medline, ISI Web of Knowledge and Scielo, in English only, and with the keywords: muscle strength, muscular endurance, transcranial direct current stimulation, tDCS. We compared the effect of anodic tDCS (a-tDCS) with a sham/control condition on muscle strength and perceived exertion results. No study mentions the negative side effects of the intervention. The data show differences between studies investigating studies of muscle strength and muscle endurance in terms of the successful use of tDCS. Studies that investigated tDCS efficiency in improving muscle strength demonstrated positive effects of a-tDCS on 66.7% of the parameters tested. Most data consistently show the influence of a-tDCS on muscle strength, but not on resistance performance.info:eu-repo/semantics/publishedVersio

    Stress and coping in sport

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    O estresse é entendido como um desequilíbrio substancial entre uma demanda e a capacidade de resposta, sob condições em que a falha em satisfazer a exigência tem consequências significativas. No esporte, esse assunto tem sido alvo de estudos a mais de quarenta anos, con- tudo, ainda há muito o que se entender sobre esse complexo tema. Assim, o objetivo dessa pesquisa foi realizar uma revisão sistemática de literatura sobre o estresse e coping no esporte, identificando as principais teorias, suas evoluções ao longo dos anos e as formas efi- cientes de investigação. Para a análise, consultamos as bases de da- dos: Google® acadêmico, Science Direct e Scielo, buscando por livros, teses, dissertações e artigos relacionados ao tema. Como resultados, destacamos o estudo de Balbinotti et al. (2013) que propôs uma nova classificação de coping, e o Modelo Transacional Cognitivo, Motivacio- nal e Relacional (Lazarus, 1991; Lazarus & Folkman, 1984), que verifica o processo de adaptação dos atletas ao contexto esportivo. Fletcher e Fletcher (2005) e Gomes (2014) também contribuíram para o desen- volvimento do Modelo de Lazarus, considerando as emoções presen- tes ao fim do processo cognitivo.Stress is seen as a substantal imbalance between demand and responsiveness, under conditons where failure to meet the requirement has signifcant consequences. In sports, this issue has been investgated over forty years, however, there is stll much to understand about this complex topic. This research aimed to conduct a systematc review of literature on stress and coping in sport, identfying the main theories, their evoluton over the years and the efcient forms of research. For the analysis, we consulted the databases: Academic Google®, Science Direct and Scielo, searching for books, theses, dissertatons and papers related to the topic. As result, we highlight the study Balbinot et al. (2013) who proposed a new classifcaton of coping, and the Transactonal Stress Model (Lazarus, 1991, Lazarus & Folkman, 1984), which verifes the process of adaptaton of athletes to the sportng context. Fletcher and Fletcher (2005) and Gomes (2014) also contributed to the development of Lazarus Model in an emoton perspectve.info:eu-repo/semantics/publishedVersio

    Foliar C, N, and P stoichiometry characterize successful plant ecological strategies in the Sonoran Desert

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    Ecological processes are centered to water availability in drylands; however, less known nutrient stoichiometry can help explain much of their structure and ecological interactions. Here we look to the foliar stoichiometry of carbon (C), nitrogen (N), and phosphorus (P) of 38 dominant plant species from the Sonoran Desert, grouped in four different functional types to describe ecological characteristics and processes. We found that foliar N, C:N, C:P, and N:P stoichiometric ratios, but not P, were higher than those known to most other ecosystems and indicate P but not N limitations in leaves. Biological N fixers (BNF) had even higher leaf N concentrations, but bio-elemental concentrations and stoichiometry ratios were not different to other non-N-fixing legume species which underscores the need to understand the physiological mechanisms for high N, and to how costly BNF can succeed in P-limiting drylands environments. Stoichiometry ratios, and to lesser extent elemental concentrations, were able to characterize BNF and colonizing strategies in the Sonoran Desert, as well as explain leaf attribute differences, ecological processes, and biogeochemical niches in this dryland ecosystem, even when no direct reference is made to other water-limitation strategies
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