5,041 research outputs found
Low-dimensional affine synchronizing groups
Tese de mestrado em Matemática, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2012The synchronization property emerged from finite state automata and transformation semigroup theory. Synchronizing permutation groups were introduced by Arnold and Steinberg to study the Cerný Conjecture. In this thesis we study the synchronization property in affine permutation groups of low-dimensions. J.E. Pin proved that one-dimensional affine groups are synchronizing. Hence our main results concern affine groups in dimension 2. We used the characterization given by Neumann of synchronization using graph theory, which relies on the study of the equality between the clique number and the chromatic number of certain graphs invariant under the actions of a group, called the suitability property. It turned out that some of such graphs for two-dimensional affine groups have an interesting geometry and are part of a widely studied class of graphs, the generalized Paley graphs. Further, we used the properties of the theta-function defined by Lovász connected to eigenvalues of a graph to obtain a necessary condition for the suitability in edge-transitive and vertex-transitive graphs. In this thesis we stated a criterion to decide if a generalized Paley graph is suitable. Then we used the tools referred to above and we presented conditions for twodimensional affine groups to be synchronizing.A propriedade de sincronização surgiu no contexto da teoria de autómatos e semigrupos de transformaçãoo. Arnold and Steinberg definiram os grupos de permutação sincronizantes com o objectivo de estudar a Conjectura de Cerný por outra perspectiva. Nesta tese estudamos a propriedade de sincronização em grupos afins de pequenas dimensões. Dado que J.E. Pin provou que os grupos afins de dimensão 1 são sempre sincronizantes, os resultados principais desta tese aplicam-se a grupos afins bidimensionais. Peter Neumann estudou os grupos sincronizantes usando teoria de grafos. Esta caracterização consiste no estudo de grafos invariantes sobre a acção de um grupo e em determinar se os seus números cromático e de clique coincidem. Descobrimos que alguns grafos invariantes sobre a acção de grupos afinns bidimensionais tinham uma geometria simétrica e que faziam parte de uma classe amplamente estudada de grafos, conhecidos como grafos de Paley generalizados. Como ferramenta extra, estudámos a função-teta, um número invariante num grafo, que foi definida por Lovász. Esta função possui uma caracterização que utiliza os valores próprios da matriz de adjacência do grafo e que nos permitiu concluir uma condição suficiente para a igualdade no número cromático e de clique em grafos cujo grupo de automorfismos é transitivo nas arestas e nos vértices. Nesta tese estabelecemos um critério para a igualdade no número cromático e de clique nos grafos de Paley generalizados e usámos esse resultado, bem como as ferramentas anteriormente referidas, para obter uma caracterização dos grupos afins bidimensionais sincronizantes
Crescimento foliar em Xylopia aromatica (Lam) Mart. (Annonaceae): implicações sobre a palatabilidade para lagartas de Stenoma scitiorella Walker 1864 (Lepidoptera: Elachistidae)
Variations in specific foliar mass and water content, nitrogen, soluble carbohydrates and tannins were studied during the growth and maturation processes of the Xylopia aromatica leaves, to determine the effects of such alterations on the herbivory of Stenoma scitiorella caterpillars. This work was carried out in the physiognomy of the typical cerrado of the Parque Estadual de Vassununga, Gleba Pé-de Gigante, Santa Rita do Passa Quatro, São Paulo State, Brazil. While nutritional quality (water and nitrogen) decreases during expansion and maturation of Xylopia aromatica leaves, the chemical (tannins) and physical (sclerophylly) defenses are raised. In agreement with the observations on herbivory, the results support the hypothesis that the reduction in palatability and increase in chemical defenses of Xylopia aromatica leaves account for the caterpillars' preference for young expanding leaves.Com o objetivo de avaliar os efeitos do crescimento e do amadurecimento de folhas de Xylopia aromatica sob o ataque de lagartas de Stenoma scitiorella, foram estudados a variação da área, massa foliar específica, bem como os teores de água, nitrogênio, hidratos de carbono e taninos durante estes processos. O trabalho foi desenvolvido numa fisionomia de cerrado stricto sensu na Gleba Pé-de-Gigante do Parque Estadual de Vassununga, localizado no município de Santa Rita do Passa Quatro, Estado de São Paulo, Brasil. A expansão e o amadurecimento das folhas de Xylopia aromatica resultaram na redução da qualidade nutricional e no aumento de defesas químicas e físicas. Concordando com as observações realizadas sobre a herbivoria, os resultados permitem supor que a redução na palatabilidade das folhas pode explicar a preferência das lagartas por folhas jovens ainda no início do processo de expansão.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Fauna used in popular medicine in Northeast Brazil
<p>Abstract</p> <p>Background</p> <p>Animal-based remedies constitute an integral part of Brazilian Traditional Medicine. Due to its long history, zootherapy has in fact become an integral part of folk medicine both in rural and urban areas of the country. In this paper we summarize current knowledge on zootherapeutic practices in Northeast of Brazil, based on information compiled from ethnobiological scientific literature.</p> <p>Methods</p> <p>In order to examine the diversity of animals used in traditional medicine in Northeast of Brazil, all available references or reports of folk remedies based on animals sources were examined. 34 sources were analyzed. Only taxa that could be identified to species level were included in assessment of medicinal animal species. Scientific names provided in publications were updated.</p> <p>Results</p> <p>The review revealed that at least 250 animal species (178 vertebrates and 72 invertebrates) are used for medicinal purposes in Northeast of Brazil. The inventoried species comprise 10 taxonomic categories and belong to 141 Families. The groups with the greatest number of species were fishes (n = 58), mammals (n = 47) and reptiles (n = 37). The zootherapeutical products are used for the treatment of different illnesses. The most widely treated condition were asthma, rheumatism and sore throat, conditions, which had a wide variety of animals to treat them with. Many animals were used for the treatment of multiple ailments. Beyond the use for treating human diseases, zootherapeutical resources are also used in ethnoveterinary medicine</p> <p>Conclusion</p> <p>The number of medicinal species catalogued was quite expressive and demonstrate the importance of zootherapy as alternative therapeutic in Northeast of Brazil. Although widely diffused throughout Brazil, zootherapeutic practices remain virtually unstudied. There is an urgent need to examine the ecological, cultural, social, and public health implications associated with fauna usage, including a full inventory of the animal species used for medicinal purposes and the socio-cultural context associated with their consumption.</p
Detec??o autom?tica de exsudatos e microaneurismas em imagens de retinopatia diab?tica utilizando o algoritmo bioinspirado na col?nia artificial de abelhas e processamento digital de imagens
O diagn?stico da retinopatia diab?tica, em imagens do fundo do olho, impulsionou o desenvolvimento de algoritmos de processamento que fossem capazes de identificar e classificar patologias automaticamente. As t?cnicas de processamento digital de imagens, aplicadas a medicina, facilitam a visualiza??o e identifica??o de patologias a partir de minimiza??o de artefatos indesej?veis nas imagens. O objetivo do presente trabalho consiste em implementar pelo m?todo baseado na col?nia artificial de abelhas (Artificial Bee Colony - ABC), para adetec??o de exsudatos, e o uso de t?cnicas de processamento digital de imagens para facilitar nos processos de detec??o e classifica??o das microaneurismas. Como sinais de entrada para os algoritmos, foram utilizadas as imagens do banco de dados da Diaretdb1. T?cnicas de pr?-processamento foram utilizadas para realizar a exclus?o do disco ?ptico (proje??o luminosa decorrente dos exames de fundoscopia), e uma m?scara foi proposta para encontrar nas imagens a patologia, com base na forma e tamanho da mesma. Para a avalia??o dos algoritmos desenvolvidos foram utilizadas as taxas de sensibilidade, especificidade e acur?cia das imagens. Na detec??o dos exsudatos os valores coletados ap?s o pos-processamento foram
85% de sensibilidade, 92% de especificidade e 96% de acur?cia. Na detec??o e classifica ??o das microaneurismas, os testes retornaram 75% de sensibilidade, 99% de especificidade e 98% de acur?cia. Conforme as imagens resultantes dos processos de detec??o, foram identificados 52 pacientes com a presen?a de exsudatos em compara??o com o banco de dados que diagnosticaram 48 pacientes com a doen?a. O algoritmo de classifica??o detectou a evid?ncia de microaneurismas em 75 pacientes e o banco de dados diagnosticou a patologia em 71
A zooterapia popular no Estado da Bahia: registro de novas espécies animais utilizadas como recursos medicinais
Relação entre humanos e primatas (Sapajus sp.) às margens do Rio São Francisco, Nordeste, Brasil
The recurrent alterations of natural habitats promoted by humans increase their proximity to
the wild fauna, which favors, among other things, the interactions between humans and
nonhuman primates. Ethnoprimatology studies these interactions, taking into account that
they have been occuring for a long period of time. It is important to understand the
perceptions and attitudes of the residents of the Vila Nobre neighborhood in the city of Paulo
Afonso, State of Bahia, in relation to the Galician capuchin monkeys (Sapajus sp.) in order to
clarify the socio-environmental factors of this relationship. Thus, to characterize the residents'
perceptions and attitudes regarding the recent occurrence of the Galician capuchin monkey,
the present study aims at the identification of conflicts and their possible causes. The study
was conducted through semi-structured interviews as well as informal conversations with
local residents between May 2012 and July 2015. Respondents were residents of the
neighborhood since their childhood. All interviewees (N = 21) stated that these monkeys had
never occurred in the neighborhood before 2011. The great majority of the interviewees
(95.4%) associate the occurrence of the monkeys with local fruit plantations. The monkeys
invade orchards, feeding on all cultivated items, and when unsatisfied, they invade residences
in search of food. In response, some residents (14.2%) adopted aggressive measures towards
the invading monkeys. All interviewees consider the Galician capuchin monkeys important to
nature. The interactions between the human beings and the Galician capuchin monkeys are
generally peaceful as positive feelings stand out to the negative ones. Therefore, the scenario
is favorable to the adoption of environmental educational aimed at the protection of the
Galician capuchin monkeys and their habitat, as well as the protection of the residents and
their residences, providing improvements in the cohabitation relationship between humans
and primate
Life course factors associated with metabolically healthy obesity: a protocol for the systematic review of longitudinal studies.
BACKGROUND: There is heterogeneity among obese individuals, as some appear to have healthier metabolic profiles and decreased health risks. These individuals are defined as metabolically healthy obese (MHO), whilst those with unhealthy metabolic profiles are defined as metabolically unhealthy obese (MUO). To date, most research on MHO has been cross-sectional or focused on disease prognosis. However, longitudinal studies are required to provide greater insight into the life course factors that contribute to the development of MHO. This study aims to systematically review longitudinal studies investigating the association between life course exposures and future MHO status. METHODS: Electronic databases (MEDLINE, SCOPUS, and Web of Science) will be searched using a trialled search strategy. Studies will be included following a double-screening process according to inclusion criteria to assess eligibility. Studies eligible for inclusion will include those that have a longitudinal observational design where a life course exposure occurred or was measured at least 1 year before the outcome, investigate a human study population, are published in English after 1956, and investigate the association between ≥ 1 life course exposure and ≥ 1 outcome that reflects a measure of cardiometabolic resilience to obesity. Accepted life course exposures will include body size, body composition, pubertal development, smoking, diet, physical activity, sedentary behaviour, and psychosocial stress. The primary measure of cardiometabolic resilience to obesity will be MHO as an outcome (at follow-up). Studies investigating the development of cardiometabolic risk factors in an obese group without specifying MHO will also be accepted, such as the development of the metabolic syndrome (MetS) in an obese group. Key results of included studies will be tabulated, and a narrative synthesis will be conducted. DISCUSSION: This will be the first systematic review to summarise the literature on the life course correlates of MHO. Importantly, it may highlight which modifiable lifestyle factors could be targeted to delay the onset of cardiometabolic complications among the obese. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42017057992
Characterisation of large changes in wind power for the day-ahead market using a fuzzy logic approach
Wind power has become one of the renewable resources with a major growth in the electricity market. However, due to its inherent variability, forecasting techniques are necessary for the optimum scheduling of the electric grid, specially during ramp events. These large changes in wind power may not be captured by wind power point forecasts even with very high resolution Numerical Weather Prediction (NWP) models. In this paper, a fuzzy approach for wind power ramp characterisation is presented. The main benefit of this technique is that it avoids the binary definition of ramp event, allowing to identify changes in power out- put that can potentially turn into ramp events when the total percentage of change to be considered a ramp event is not met. To study the application of this technique, wind power forecasts were obtained and their corresponding error estimated using Genetic Programming (GP) and Quantile Regression Forests. The error distributions were incorporated into the characterisation process, which according to the results, improve significantly the ramp capture. Results are presented using colour maps, which provide a useful way to interpret the characteristics of the ramp events
Ultra-processed food consumption and obesity in the Australian adult population
Background: Rapid simultaneous increases in ultra-processed food sales and obesity prevalence have been observed worldwide, including in Australia. Consumption of ultra-processed foods by the Australian population was previously shown to be systematically associated with increased risk of intakes of nutrients outside levels recommended for the prevention of obesity. This study aims to explore the association between ultra-processed food consumption and obesity among the Australian adult population and stratifying by age group, sex and physical activity level. Methods: A cross-sectional analysis of anthropometric and dietary data from 7411 Australians aged ≥20 years from the National Nutrition and Physical Activity Survey 2011–2012 was performed. Food consumption was evaluated through 24-h recall. The NOVA system was used to identify ultra-processed foods, i.e. industrial formulations manufactured from substances derived from foods and typically added of flavours, colours and other cosmetic additives, such as soft drinks, confectionery, sweet or savoury packaged snacks, microwaveable frozen meals and fast food dishes. Measured weight, height and waist circumference (WC) data were used to calculate the body mass index (BMI) and diagnosis of obesity and abdominal obesity. Regression models were used to evaluate the association of dietary share of ultra-processed foods (quintiles) and obesity indicators, adjusting for socio-demographic variables, physical activity and smoking. Results: Significant (P-trend ≤ 0.001) direct dose–response associations between the dietary share of ultra-processed foods and indicators of obesity were found after adjustment. In the multivariable regression analysis, those in the highest quintile of ultra-processed food consumption had significantly higher BMI (0.97 kg/m2; 95% CI 0.42, 1.51) and WC (1.92 cm; 95% CI 0.57, 3.27) and higher odds of having obesity (OR = 1.61; 95% CI 1.27, 2.04) and abdominal obesity (OR = 1.38; 95% CI 1.10, 1.72) compared with those in the lowest quintile of consumption. Subgroup analyses showed that the trend towards positive associations for all obesity indicators remained in all age groups, sex and physical activity level. Conclusion: The findings add to the growing evidence that ultra-processed food consumption is associated with obesity and support the potential role of ultra-processed foods in contributing to obesity in Australia
Heterogeneities in leishmania infantum infection : using skin parasite burdens to identify highly infectious dogs
Background: The relationships between heterogeneities in host infection and infectiousness (transmission to arthropod vectors) can provide important insights for disease management. Here, we quantify heterogeneities in Leishmania infantum parasite numbers in reservoir and non-reservoir host populations, and relate this to their infectiousness during natural infection. Tissue parasite number was evaluated as a potential surrogate marker of host transmission potential.
Methods: Parasite numbers were measured by qPCR in bone marrow and ear skin biopsies of 82 dogs and 34 crab-eating foxes collected during a longitudinal study in Amazon Brazil, for which previous data was available on infectiousness (by xenodiagnosis) and severity of infection.
Results: Parasite numbers were highly aggregated both between samples and between individuals. In dogs, total parasite abundance and relative numbers in ear skin compared to bone marrow increased with the duration and severity of infection. Infectiousness to the sandfly vector was associated with high parasite numbers; parasite number in skin was the best predictor of being infectious. Crab-eating foxes, which typically present asymptomatic infection and are non-infectious, had parasite numbers comparable to those of non-infectious dogs.
Conclusions: Skin parasite number provides an indirect marker of infectiousness, and could allow targeted control particularly of highly infectious dogs
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