862 research outputs found

    Extensive local adaptation within the chemosensory system following Drosophila melanogaster's global expansion.

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    How organisms adapt to new environments is of fundamental biological interest, but poorly understood at the genetic level. Chemosensory systems provide attractive models to address this problem, because they lie between external environmental signals and internal physiological responses. To investigate how selection has shaped the well-characterized chemosensory system of Drosophila melanogaster, we have analysed genome-wide data from five diverse populations. By couching population genomic analyses of chemosensory protein families within parallel analyses of other large families, we demonstrate that chemosensory proteins are not outliers for adaptive divergence between species. However, chemosensory families often display the strongest genome-wide signals of recent selection within D. melanogaster. We show that recent adaptation has operated almost exclusively on standing variation, and that patterns of adaptive mutations predict diverse effects on protein function. Finally, we provide evidence that chemosensory proteins have experienced relaxed constraint, and argue that this has been important for their rapid adaptation over short timescales

    Graph Creation, Visualisation and Transformation

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    We describe a tool to create, edit, visualise and compute with interaction nets - a form of graph rewriting systems. The editor, called GraphPaper, allows users to create and edit graphs and their transformation rules using an intuitive user interface. The editor uses the functionalities of the TULIP system, which gives us access to a wealth of visualisation algorithms. Interaction nets are not only a formalism for the specification of graphs, but also a rewrite-based computation model. We discuss graph rewriting strategies and a language to express them in order to perform strategic interaction net rewriting

    Meissner state in finite superconducting cylinders with uniform applied magnetic field

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    We study the magnetic response of superconductors in the presence of low values of a uniform applied magnetic field. We report measurements of DC magnetization and AC magnetic susceptibility performed on niobium cylinders of different length-to-radius ratios, which show a dramatic enhance of the initial magnetization for thin samples, due to the demagnetizing effects. The experimental results are analyzed by applying a model that calculates the magnetic response of the superconductor, taking into account the effects of the demagnetizing fields. We use the results of magnetization and current and field distributions of perfectly diamagnetic cylinders to discuss the physics of the demagnetizing effects in the Meissner state of type-II superconductors.Comment: Accepted to be published in Phys. Rev. B; 15 pages, 7 ps figure

    An intrusive method for film thickness measurement on smooth horizontal tubes for subcooled water

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    Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.Falling film evaporation technique is widely used in different applications such as in heat exchangers in desalination devices, absorption/desorption-type chillers, OTEC (ocean thermal energy conversion primer), petrochemical, and chemical process industries, just to mention a few industries. However, in spite of numerous studies the complete understanding is not totally clear yet, even some basic phenomena such as the behavior the film thickness and its relationship with the heat and mass transfer coefficients. The objective of the present work is present the study of an intrusive method for measuring a descending film thickness employing subcooled water as the working fluid at atmospheric conditions. The method used a novel configuration (leverage effect) in which a micrometer reading has its precision improved. As a needle tip touches the liquid film, an electrical current flows in signalizing the tip position and, consequently, the film thickness. The current proposal presents an accuracy 22% when compared with the theoretical result of Nusselt.cf201

    Outward-inward information flux in an opinion formation model on different topologies

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    A simple model of opinion formation dynamics in which binary-state agents make up their opinions due to the influence of agents in a local neighborhood is studied using different network topologies. Each agent uses two different strategies, the Sznajd rule with a probability qq and the Galam majority rule (without inertia) otherwise; being qq a parameter of the system. Initially, the binary-state agents may have opinions (at random) against or in favor about a certain topic. The time evolution of the system is studied using different network topologies, starting from different initial opinion densities. A transition from consensus in one opinion to the other is found at the same percentage of initial distribution no matter which type of network is used or which opinion formation rule is used.Comment: 11 pages including figures. To appear in Physica

    Influência da profundidade de plantio na propagação do gladíolo (Gladiolus grandiflorus) andr. cv. Snow Princess

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    A profundidade de plantio dos cormilhos influi na produção e qualidade do material de propagação. Em maiores profundidades, o peso médio por unidade produzida é maior. Para produzir bulbos dos tipos jumbo até o tipo 5, a profundidade de 7,3 cm foi a melhor. A profundidade de 5,6 cm foi melhor para quantidade. Maiores profundidades produzem menor cormilhos.The depth of planting cormels has influence on production and quality of propagation material. In bigger depth the average weight per unity planted is bigger. For production of corms type: jumbo untill type 5 the depth of 7.3 cm was the best one. The depth of 5.6 cm was the best for quality. Bigger depth produce less cormels

    Propagação do gladíolo (Gladiolus grandiflorus) andr. cv. Snow Princess: produção de material de propagação e flores pelos bulbos tipo jumbo e tipo 1

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    Corms of 2nd cycle, type jumbo with 84 g/unity and type 1 with 35 g/unity were compared. It was verified that: type jumbo had better profit in the production of: weight of corms, number of corms, lenght of stipe, lenght of spike and stipe of better quality. The type number 1 showed better profit for weight of corms planted by weight of corms and cormels harvest.Bulbos de 2° ciclo, tipo jumbo, com 84 g/unidade e tipo 1, com 35 g/unidade, foram comparados. Verificou-se que: o tipo jumbo teve melhor rendimento de: peso de bulbos; número de bulbos; comprimento da haste floral; comprimento da espiga floral e hastes florais de melhor qualidade. Otipo 1 apresentou melhor rendimento para peso de bulbos plantados por peso de bulbos e cormilhos colhidos

    Propagação do gladíolo (Gladioius grandiflorus) andr. cv. Snow Princess: comportamento de seis tipos de materiais vegetativos, na produção de flores e material de propagação

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    Corms of the same cycle, with near weight and size, presented resembling behaviour for production of flowers, corms and cormels. Greater corms, type 1and 2showed better profit of flowers, corms and cormels than others types, decreasing this profit with the reduction of the size of corms per unity planted. In function of planted weight, the smallest units showed better profit.Bulbos de mesmo ciclo, com pesos e tamanhos próximos, apresentaram comportamentos semelhantes para a produção de flores, bulbos e cormilhos. Os bulbos maiores, tipos 1 e 2, tiveram melhor rendimento de flores, bulbos e cormilhos que os demais tipos, decrescendo esse rendimento com a redução do tamanho dos bulbos por unidade plantada. Em função do peso plantado, as unidades menores apresentaram melhor desempenho

    Dietary inflammatory index and prevalence of overweight and obesity in Brazilian graduates from the Cohort of Universities of Minas Gerais (CUME project)

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    Objectives: The aim of this study was to evaluate the independent association of the dietary inflammatory index (DII ) score with overweight and obesity in Brazilian participants of the Cohort of Universities of Minas Gerais (CUME project). Methods: This was a cross-sectional study consisting of 3,151 graduates and postgraduates (2197 women) with a mean (SD) age of 36.3 y (§9.4 y). Sociodemographic characteristics, lifestyle, and anthropometric data were assessed via online self-reported questionnaire. Additionally, a validated food frequency questionnaire with 144 food items was used to generate energy-adjusted DII (E-DIITM) scores, which evaluated the inflammatory potential of the diet. Results: The prevalence of overweight and obesity were 28.2% and 11%, respectively. Participants in the highest E-DII quartile (most proinflammatory diet) were more likely to be smokers/former smokers; sedentary; and consumers of red and ultra-processed meats, fats and oils (excluding olive oil), bottled fruit juices and soft drinks, sugars, sweets, and higher overall caloric intake, compared with the first quartile of E-DII. Both men and women in the fourth E-DII quartile had the highest prevalence of overweight and obesity (prevalence ratio [PR], 1.35; 95% confidence interval [CI], 1.14 1.59 and PR, 1.97; 95% CI, 1.20 3.22, respectively, in men; PR, 1.38; 95% CI, 1.17 to 1.65 and PR, 1.95; 95% CI, 1.31 2.90, respectively, in women). Conclusion: The most proinflammatory dietary pattern was associated with a higher prevalence of overweight and obesity and other unhealthy lifestyles including being sedentary, smoking, and consuming a obesogenic diet
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