69 resultados para Cocoon


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We explore the influence of the choice of attenuation factor on Katz centrality indices for evolving communication networks. For given snapshots of a network observed over a period of time, recently developed communicability indices aim to identify best broadcasters and listeners in the network. In this article, we looked into the sensitivity of communicability indices on the attenuation factor constraint, in relation to spectral radius (the largest eigenvalue) of the network at any point in time and its computation in the case of large networks. We proposed relaxed communicability measures where the spectral radius bound on attenuation factor is relaxed and the adjacency matrix is normalised in order to maintain the convergence of the measure. Using a vitality based measure of both standard and relaxed communicability indices we looked at the ways of establishing the most important individuals for broadcasting and receiving of messages related to community bridging roles. We illustrated our findings with two examples of real-life networks, MIT reality mining data set of daily communications between 106 individuals during one year and UK Twitter mentions network, direct messages on Twitter between 12.4k individuals during one week.

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Earthworms are significant ecosystem engineers and are an important component of the diet of many vertebrates and invertebrates, so the ability to predict their distribution and abundance would have wide application in ecology, conservation and land management. Earthworm viability is known to be affected by the availability and quality of food resources, soil water conditions and temperature, but has not yet been modelled mechanistically to link effects on individuals to field population responses. Here we present a novel model capable of predicting the effects of land management and environmental conditions on the distribution and abundance of Aporrectodea caliginosa, the dominant earthworm species in agroecosystems. Our process-based approach uses individual based modelling (IBM), in which each individual has its own energy budget. Individual earthworm energy budgets follow established principles of physiological ecology and are parameterised for A. caliginosa from experimental measurements under optimal conditions. Under suboptimal conditions (e.g. food limitation, low soil temperatures and water contents) reproduction is prioritised over growth. Good model agreement to independent laboratory data on individual cocoon production and growth of body mass, under variable feeding and temperature conditions support our representation of A. caliginosa physiology through energy budgets. Our mechanistic model is able to accurately predict A. caliginosa distribution and abundance in spatially heterogeneous soil profiles representative of field study conditions. Essential here is the explicit modelling of earthworm behaviour in the soil profile. Local earthworm movement responds to a trade-off between food availability and soil water conditions, and this determines the spatiotemporal distribution of the population in the soil profile. Importantly, multiple environmental variables can be manipulated simultaneously in the model to explore earthworm population exposure and effects to combinations of stressors. Potential applications include prediction of the population-level effects of pesticides and changes in soil management e.g. conservation tillage and climate change.

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This paper investigates the feasibility of using approximate Bayesian computation (ABC) to calibrate and evaluate complex individual-based models (IBMs). As ABC evolves, various versions are emerging, but here we only explore the most accessible version, rejection-ABC. Rejection-ABC involves running models a large number of times, with parameters drawn randomly from their prior distributions, and then retaining the simulations closest to the observations. Although well-established in some fields, whether ABC will work with ecological IBMs is still uncertain. Rejection-ABC was applied to an existing 14-parameter earthworm energy budget IBM for which the available data consist of body mass growth and cocoon production in four experiments. ABC was able to narrow the posterior distributions of seven parameters, estimating credible intervals for each. ABC’s accepted values produced slightly better fits than literature values do. The accuracy of the analysis was assessed using cross-validation and coverage, currently the best available tests. Of the seven unnarrowed parameters, ABC revealed that three were correlated with other parameters, while the remaining four were found to be not estimable given the data available. It is often desirable to compare models to see whether all component modules are necessary. Here we used ABC model selection to compare the full model with a simplified version which removed the earthworm’s movement and much of the energy budget. We are able to show that inclusion of the energy budget is necessary for a good fit to the data. We show how our methodology can inform future modelling cycles, and briefly discuss how more advanced versions of ABC may be applicable to IBMs. We conclude that ABC has the potential to represent uncertainty in model structure, parameters and predictions, and to embed the often complex process of optimizing an IBM’s structure and parameters within an established statistical framework, thereby making the process more transparent and objective.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The health transition experienced in Brazilian health care model requires a metamorphosis in human and society, placing new demands on health and education. The Faculty of Science, Culture and Extension of Rio Grande do Norte (Facex), aware of their responsibilities to the Health System, which brings the principle of comprehensiveness as its structural axis, dared to implement a course of nursing in complex thinking and Experiential Pedagogy Humanescente with curriculum inter / transdisciplinary. For deployment of proprosta was not enough to reform thinking of educators, there was a need corporalizar new teaching practices that are aimed at the integral formation of human beings. In this context, emerged the workshop on Human Education autopoietic, self-forming area of the educator, where he developed an Action Research Existential (PA-E) which enabled experience, describe and analyze how the human autopoietic educators could contribute to the practice educational humanescente transdisciplinary curriculum project. Were worked out in meetings, knowledge necessary to practice the transdisciplinary 1st Meeting - learn to create; 2nd Meeting - learn to recognize the laws of nature with emphasis on complexity theory, 3rd Meeting - learn to organize, 4th meeting - namely autoestruturar themselves; 5th Meeting - know how to choose, 6th Meeting - knowing innovate 7th Meeting - namely exchange. Next an autobiographical perspective, we chose the metaphorical possibility to narrate the ways and strategies covered by the author and apprentice in the company of the Little Prince de Saint-Exupery, in search of a sensible pedagogical practice complex, which promotes re-enchant transdisicplinar education. The route involved five methodological connections: a literature review which relate to training for care in undergraduate nursing: the study of learning processes that drive the formation humanopoiética, emphasizing the relationship that involves the complexity and embodiment in the educational process transdisciplinary, highlighting the analysis of what is to learn from the findings of biosciences and recent cognitive theories of Maturana and Varela, the description of the interdisciplinary curriculum of the nursing course of Facex and Training Workshop, Human autopoietic, with emphasis on Experiential Education Humanescente; the report of seven meetings of the Workshops (cocoon), recording the experiences and listening to educators (luminescent butterflies), the final reflections with learning opportunized. Experientiality lived through, the expressions and words, educators say the influence of workshops for their teaching practices, highlighting it as a space for selforganizing, creating, learning and enchantment, and can identify the workshop as a place of transformation necessary for deployment an interdisciplinary curriculum. The knowledge emerging from the study indicate the need for permanent spaces of self, in which the educator learns from its body, between cognitive processes and vital, and in the experiences of their formative process the opportunity to act on the dimensions of knowing and being

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Análogos do hormônio juvenil (AHJ) têm sido testados como reguladores de crescimento de Bombyx mori L., com vistas ao incremento da produção de casulos. Esses produtos, quando aplicados em doses adequadas, prolongam o período larval. Os efeitos da aplicação de AHJ podem variar com o produto, a linhagem e o momento de aplicação. Este estudo teve por objetivo avaliar o efeito da aplicação tópica, em diferentes momentos, de três análogos do hormônio juvenil sobre o crescimento dos insetos e a produção de seda da linhagem brasileira C115xN108 do bicho-da-seda. Os produtos piriproxifem, metoprene e fenoxicarbe foram aplicados em larvas do bicho-da-seda a 24h, 48h, 72h e 96h após o início do quinto ínstar (HQI) e seus efeitos sobre características biológicas larvais e adultas e a produção de seda foram avaliados. Independentemente do momento de aplicação, os três produtos afetaram todos os parâmetros avaliados. A reserva de nutrientes acumulada durante o período larval prolongado dos insetos tratados foi destinada ao crescimento das glândulas sericígenas e, também, convertida em peso corporal, com conseqüentes incrementos na produção de seda. Aplicações entre 48 e 72 HQI provocaram os maiores incrementos na biomassa e na produção de casulos de B. mori. Variações no momento de aplicação de 24h e 96h não influenciaram a emergência ou a oviposição de adultos de B. mori, nem a viabilidade dos ovos.

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The great majority of analytical models for extragalactic radio sources suppose self-similarity and can be classified into three types: I, II and III. We have developed a model that represents a generalization of most models found in the literature and showed that these three types are particular cases. The model assumes that the area of the head of the jet varies with the jet size according to a power law and the jet luminosity is a function of time. As it is usually done, the basic hypothesis is that there is an equilibrium between the pressure exerted both by the head of the jet and the cocoon walls and the ram pressure of the ambient medium. The equilibrium equations and energy conservation equation allow us to express the size and width of the source and the pressure in the cocoon as a power law and find the respective exponents. All these assumptions can be used to calculate the evolution of the source size, width and radio luminosity. This can then be compared with the observed width-size relation for radio lobes and the power-size (P-D) diagram of both compact (GPS and CSS) and extended sources from the 3CR catalogue. In this work we introduce two important improvement as compared with a previous work: (1)We have put together a larger sample of both compact and extended radio sources

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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We estimated the number of larval instars of the ant Ectatomma vizottoi (Ectatomminae), by measuring the maximum width of the head capsules of 208 larvae and the morphology of the immature stages (eggs, larvae and pupae) and adults. There are three larval instars during the post-embryonic development. The reproductive eggs are dark brown. Hairs are present beginning with the first instar, are uniformly distributed over the larval body, and do not vary in length in the three instars. Pupae are protected by a light-brown silk cocoon. Adults of the worker and queen castes can be differentiated by size.

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O objetivo deste trabalho foi avaliar se a suplementação da dieta do bicho-da-seda com extrato hidrossolúvel de soja (EHS) interfere na produção de casulos e no consumo de folhas de amoreira (Morus alba L.) de diferentes cultivares pelas lagartas. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 4x5, com quatro cultivares de amoreira ('IZ64', 'IZ56/4', 'FM86' e 'FMSM') e cinco dietas (folhas não tratadas, folhas umedecidas com água, folhas enriquecidas com EHS, em três níveis: suplementação da dieta com 5, 10 e 20% de PB). O EHS foi aspergido sobre as folhas, tendo a água como agente dispersante. O consumo foi verificado pela diferença entre a quantidade de folhas fornecidas e a quantidade não consumida pelas lagartas. A ingestão de alimento apresentou-se de forma quadrática, diminuindo à medida que o EHS foi adicionado à dieta. Houve interação dos fatores cultivar e dieta. O fornecimento de folhas de amoreira com acréscimo proteico de 10% por meio do EHS melhorou a qualidade dos casulos do bicho-da-seda com a utilização das cultivares 'IZ56/4' e 'FMSM'. A pulverização de EHS nas folhas da cultivar 'IZ64' prejudicou a produção de casulos. Lagartas do bicho-da-seda, alimentadas com folhas de amoreira sem suplementação, produziram cascas séricas mais pesadas com folhas das cultivares 'IZ64' e 'FMSM'. A aspersão de água nas folhas incrementou o peso de cascas séricas produzidas a partir da cultivar 'FM86'. A suplementação da dieta com EHS diminui o consumo da lagarta do bicho-da-seda. A aplicação de EHS influencia a produção de casulos em função da cultivar utilizada.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Worker larvae of Melipona rufiventris, M. quadrifasciata and M. compressipes were treated topically with juvenile hormone (JH) during the cocoon-spinning phase. Examination of the tergites of the queens obtained following JH application showed induced differentiation into adults with full female (queen) traits. Melipona workers had tergal glands only in tergite II, whereas natural and JH-induced queens had tergal glands in tergite II plus additional glands in at least one other of tergites Ill to VII.

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A number of amphibians and reptiles have cyclic behavior, becoming inactive with the coming of the dry season. In South America this pattern of activity is common, particularly in savannah-like vegetation. During the dry season amphibians burrow into the mud or soil, and either form a cocoon or increase the osmotic concentration of body fluids to reduce evaporative water loss. Some phyllomedusid tree frogs coat their body surface with skin secretion and excrete uric acid to minimize water loss. Reptiles also retreat into shelter deep enough to avoid temperature fluctuation during estivation or reduce metabolic response to temperature. Reduction of temperature sensitivity of the metabolism seems to be a strategy common to estivating amphibians and reptiles. Despite seasonal change of the environment, some species of reptiles are active all year round.

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The cocoon, produced by most holometabolous insects, is built with silk that is usually produced by the larval salivary gland. Although this silk has been widely studied in the Lepidoptera, its composition and macromolecular arrangement remains unknown in the Hymenoptera. The macromolecular array patterns of the silk in the larval salivary gland of some meliponids, wasps, and ants were analyzed with polarized-light microscopy, and they were compared with those of Bombyx mori (Lepidoptera). There is a birefringent secretion in the glandular lumen of all larvae, due to filamentous structural proteins that display anisotropy. The silk in the distal, middle and proximal regions of the secretory portion of Formicidae and Vespidae glands presented a lattice optical pattern. We found a different pattern in the middle secretory portion of the Meliponini, with a zigzag rather than a lattice pattern. This indicates that the biopolymer fibers begin their macromolecular reorganization at this glandular region, different from the Formicidae and the Vespidae, in which the zigzag optical pattern was only found at the lateral duct. Probably, the mechanism of silk production in the Hymenoptera is a characteristic inherited from a common ancestor of Vespoidea and Sphecoidea; the alterations in the pattern observed in the Meliponini could be a derived characteristic in the Hymenoptera. We found no similarity in the macromolecular reorganization patterns of the silk between the Hymenoptera species and the silkworm.