987 resultados para Abstnt with out leave
Resumo:
Past studies into the roles of testosterone in birds have focused on species that occur in temperate regions. In such species, plasma testosterone levels are high during the establishment of territories in the spring and are associated with increased aggression. In contrast to most temperate species, tropical birds frequently defend territories year-round, during which time territoriality often occurs in a nonsexual context. The few studies that have been carried out on tropical birds show lower levels of circulating testosterone than occur in their temperate counterparts. In some year-round territorial tropical species, testosterone and aggression are dissociated, while in other species testosterone still plays a role in regulating aggression. This study examined the relationship between aggression and plasma testosterone levels in a year-round territorial, subtropical population of the buff-banded rail with characteristics typical of tropical species. Peak testosterone levels were substantially lower than those found in temperate species. Males displayed a seasonal peak in plasma testosterone level when their partners were most likely to be fertile. At other times, testosterone levels were mostly undetectable, despite year-round territoriality. We found that T levels increased with courtship behavior but showed no relationship with aggression, supporting the hypothesis that dissociation between testosterone and territoriality may be widespread among tropical avian taxa. (C) 2003 Elsevier Science (USA). All rights reserved.
Resumo:
Adiabatic self-heating tests were carried out on five New Zealand coal samples ranging in rank from lignite to high-volatile bituminous. Kinetic parameters of oxidation were obtained front the self-heating curves assuming Arrhenius behaviour. The activation energy E (kJ mol(-1)) and the pre-exponential factor A (s(-1)) were determined in the temperature range of 70-140 degreesC. The activation energy exhibited a definite rank relationship with a minimum E of 55 kJ mol(-1) occurring at a Suggate rank of similar to6.2 corresponding to subbituminous C. Either side of this rank there was a noticeable increase in the activation energy indicating lower reactivity of the coal. A similar rank trend was also observed in the R-70 self-heating rate index values that were taken from the initial portion of the self-heating curve front 40 to 70 degreesC. From these results it is clear that the adiabatic method is capable of providing reliable kinetic parameters of coal oxidation.
Resumo:
In standard cylindrical gradient coils consisting of a single layer of wires, a limiting factor in achieving very large magnetic field gradients is the rapid increase in coil resistance with efficiency. This is a particular problem in small-bore scanners, such as those used for MR microscopy. By adopting a multi-layer design in which the coil wires are allowed to spread out into multiple layers wound at increasing radii, a more favourable scaling of resistance with efficiency is achieved, thus allowing the design of more powerful gradient coils with acceptable resistance values. Previously this approach has been applied to the design of unshielded, longitudinal, and transverse gradient coils. Here, the multi-layer approach has been extended to allow the design of actively shielded multi-layer gradient coils, and also to produce coils exhibiting enhanced cooling characteristics. An iterative approach to modelling the steady-state temperature distribution within the coil has also been developed. Results indicate that a good level of screening can be achieved in multi-layer coils, that small versions of such coils can yield higher efficiencies at fixed resistance than conventional two-layer (primary and screen) coils, and that performance improves as the number of layers of increases. Simulations show that by optimising multi-layer coils for cooling it is possible to achieve significantly higher gradient strengths at a fixed maximum operating temperature. A four-layer coil of 8 mm inner diameter has been constructed and used to test the steady-state temperature model. (C) 2003 Elsevier Inc. All rights reserved.
Resumo:
O objetivo desta pesquisa foi levantar os motivos que influenciam a evasão discente em quatro cursos de graduação da Universidade Federal do Espírito Santo. A reestruturação universitária proposta pelo REUNI - Programa de Apoio a Planos de Expansão das Universidades Federais serviu como contexto ao estudo, pois instituiu diretrizes para o combate à evasão no ensino superior. O modelo de evasão de cunho sociológico proposto por Tinto (1997) baseou as análises realizadas nesta pesquisa porque toma a instituição como responsável por ações capazes de criar um ambiente de aprendizado necessário à permanência do estudante. A pesquisa de campo quali-quantitativa foi realizada com os alunos evadidos e com os coordenadores dos cursos de Administração Diurno e Ciências Contábeis Noturno e dos novos cursos Administração Noturno e Ciências Contábeis Vespertino. Foram alcançados 95 alunos evadidos e os quatro coordenadores, sendo aplicado questionário semiaberto aos alunos evadidos e feitas entrevistas semiestruturadas com os coordenadores. Dados do sistema acadêmico (SIE/UFES) foram utilizados para o levantamento das variáveis. Os números fornecem evidências de que o resultado da aprendizagem traduzido pelo desempenho acadêmico torna-se um forte causador da evasão por abandono. O baixo coeficiente de rendimento relacionou-se ao desligamento por abandono na maioria dos casos. Em relação às formas de evasão, a desistência e o desligamento por abandono totalizaram 87,4% dos casos, com maior incidência de evasão no segundo e terceiro ano do curso. O ponto crítico da evasão parece confirmar-se do 2º ao 5º semestre e 62% dos casos de evasão que se situaram nesse lapso temporal apresentaram coeficiente de rendimento de 0,00 a 3,00. Os resultados evidenciaram os motivos que mais influenciaram os alunos a deixar o curso: i) a necessidade de trabalhar enquanto frequentava o curso, ii) a descoberta de novos interesses; iii) a incompatibilidade entre os horários do trabalho e do curso; iv) a escolha da carreira profissional ainda muito jovem e v) a falta de orientação aos alunos sobre normas, penalidades, planejamento do curso, periodização, etc. e deficiências na comunicação institucional.
Resumo:
O objetivo desta pesquisa foi discutir as interferências do acolhimento institucional e da educação escolar na constituição da subjetividade da criança que, por algum motivo, foi afastada da família e/ou responsável e se encontra sob tutela do Estado, aos cuidados de uma casa-lar, no município de Vila Velha. Para a leitura subjetiva das crianças que compuseram o cenário deste trabalho, a pesquisa ancorou-se na Perspectiva Histórico-Cultural do Desenvolvimento Humano, tendo como autores de base Lev Vigotski, Henri Wallon e Mikhail Bakhtin. A investigação ocorreu em dois espaços distintos: na “Casa-Lar Santa Cecília”, instituição que desenvolvia um programa de acolhimento institucional às crianças sob tutela pública; e numa escola de Ensino Fundamental, com crianças que estavam matriculadas no 3º ano. A metodologia utilizada nessa investigação foi o estudo de caso; trata-se, portanto, do estudo de caso de duas crianças sob tutela pública. Os procedimentos utilizados para o recolhimento do material empírico foram a observação participante e as entrevistas semiestruturadas com os profissionais do abrigo e da escola. O estudo teve enfoque em duas crianças – uma menina e um menino, ambos com dez anos de idade. O processo de destituição familiar e o acolhimento institucional sempre deixam marcas. Encontramos as marcas nas cicatrizes deixadas no corpo de Sofia em consequência dos maus-tratos; no seu silêncio, a dor por uma realidade vivida que não se desvanece. Nesse contexto, suas expectativas giravam em torno da adoção, de outro caminho, mas diferente do abrigamento. Deparamo-nos com a dor e a saudade, expressas por meio do choro, que Noah sentia de uma família que, ao longo do tempo, se foi desmembrando e se distanciando em decorrência da destituição familiar e da adoção dos irmãos; as dificuldades para elaborar esses acontecimentos e o sofrimento vivenciado diante do imenso vazio que se delineia com tantas perdas foram identificados nas manifestações de raiva, na intensificação da rispidez e da intolerância em relação, sobretudo, aos colegas de sala de aula. Por outro lado, a escola apresentou-se como um espaço significativo para essas duas crianças, que tinham, nessa instituição, a possibilidade de se constituir como alunos, da mesma forma que as outras crianças, e de vivenciar experiências no encontro com os outros que lhes traziam satisfação e, de certa forma, potencializavam o seu desenvolvimento. Encontramos indícios de ecos dos sentimentos dos outros na vida dessas crianças, bem como do impacto desses sentimentos na constituição subjetiva de cada uma delas; em outras palavras, o sentimento de pertencer a um grupo e de ter um lugar na vida de alguns membros da comunidade escolar, sobretudo, das outras crianças.
Resumo:
The United States has gone further than any country in the "privatization of security". Other countries may find the economic or financial logic in the use of contractors persuasive. The US experience with contracting out security, particularly in Iraq, was problematic, and can serve as a cautionary tale in order that other countries might learn how to avoid the pitfalls.
Resumo:
The strawberry is as non-climacteric fruit, but has a high post-harvest respiration rate, which leads to a rapid deterioration at room temperature. This study aimed to evaluate the application of biodegradable coating on postharvest conservation of organic strawberries, cv. Camarosa, packed in plastic hinged boxes and stored at 10ºC. The treatments consisted of: a) control; b) 2% cassava starch; c) 1% chitosan; and d) 2% cassava starch + 1% chitosan. Physical and chemical characteristics of fruits were evaluated at 3, 6 and 9 days of storage, and microbiological and sensory analyses were carried out at the end of the storage period. The treatments influenced positively the post-harvest quality of organic strawberries. The coating cassava starch + chitosan provided the best results, with less than 6% of loss in fruit mass, lower counts of yeast and psychrophilic microorganisms and the best appearance according to the sensory analysis.
Resumo:
Gladiolus is an ornamental species produced for cut flowers and propagated by corms. The early flowering and increase in the number of flower buds, besides the production of commercial corms are constant challenges to be addressed in the crop improvement. Commercial production of ornamentals is technologically accelerated by means of growth regulators. Among them, the auxins stand out for their key role in the adventitious rooting and cell elongation. Alternatively, the humic substances present in the organic matter also have biostimulating effect, which is very similar to the auxinic effect. Therefore, this work aimed to study the growth and development of gladiolus in response to application of different concentrations of humic acids (HA) isolated from vermicompost. Corms were soaked for 24 hours in solutions containing 0, 10, 20, 30 and 40 mmol L-1 of C from HA. The corms were planted in 10-dm³ plastic bags filled with substrate and kept in a greenhouse. Growth of shoots and roots was evaluated. The results showed that the use of HA accelerates growth, and anticipates and increases flowering of Gladiolus.
Resumo:
Differences in levels of lignin in the plant between conventional and transgenic cultivars RR has been reported by several authors, however, there are few studies evaluating the influence of spraying of glyphosate on the lignin in the plant and RR soybean seeds. The aim of this study was to evaluate the physiological quality of RR transgenic soybean seeds and the lignin contents of plants sprayed with the herbicide glyphosate. The assays were conducted both in greenhouse and field in the municipality of Lavras, MG, in the agricultural year 2007/08. The experiment was arranged in a splitplot design with four replicates, considering the treatments hand weeding and herbicide glyphosate as plots, and five RR soybean cultivars (BRS 245 RR, BRS 247 RR, Valiosa RR, Silvânia RR and Baliza RR) as splitplots. In the greenhouse, the cultivars tested were BRS 245 RR and Valiosa RR in a randomized block design with four replicates. The sprayings were carried out at stages V3, V7 and early R5 (3L/ha). The 1000 seed weight, mechanical injury, germination and germination velocity index, emergence velocity index, accelerated aging, electrical conductivity and water soaking seed test, lignin content in the seed coat, in the stem and legumes were determined. The spraying of glyphosate herbicide, in greenhouse and field, did not alter the physiological quality of seeds and the lignin contents in the plant.
Resumo:
The effect of molybdenum (Mo) on common bean grown in desiccated corn stover in a no-tillage system was evaluated under two application modes: Mo mixed with the desiccant glyphosate and Mo direct spray to the bean leaves. The treatments (four replicates) were assigned to a completely randomized block design in a split-plot arrangement with the application of Mo (0, 100, 200, 400 and 800 g ha-1) mixed with glyphosate in the main plots and Mo foliar spray (0 and 100 g ha-1) in the sub-plots. The field experiments were carried out in 2009 and 2010 in the municipality of Coimbra, Minas Gerais State, with the common bean cultivar Ouro Vermelho. Mo mixed with glyphosate had neither an effect on common bean yield nor on the Mo and N contents in leaves, however it increased the Mo and N contents in seeds. Application of Mo via foliar spray increased Mo content in leaves and Mo and N contents in seeds. The reapplication of molybdenum with glyphosate for desiccation in subsequent crops caused a cumulative effect of Mo content in bean seeds.
Resumo:
The objective of this study was to evaluate the substrate, cuttings collection time, the position and the cutting depth, and the propagation environment on rooting of 'Purple Valinhos' fig tree cuttings in Southwestern Paraná, Brazil. Two experiments were carried out at UTFPR, Câmpus Dois Vizinhos, with hardwoods cuttings from Roxo de Valinhos fig tree. The first experiment used a randomized block design, in 3 x 3 x 2 factorial (substrate x environment x collection time), with four replications of 10 cuttings per plot. The cuttings were collected in the first fifteen days of July and August. The substrates were sand, soil and the mixture of these [1:1 (v / v)]. The environments used were open sky, tunnel with plastic cover and tunnel with half-shade black net cover. The second experiment used a randomized block design, 2 x 2 x 3 factorial (shoot cutting position x soil cover x shoot cutting depth), with four replications of 12 cuttings per plot. In the factor position, the vertically (0 º inclination) and inclined (45 º inclination) shoot cuttings were evaluated. Soil cover was tested with mulching plastic cover or not. The tested depths were 1/3, 1/2 and 2/3 in relation to the total length of the shoot cutting. In both experiments, the following were analyzed: rooting and mortality indices, number of leaves and primary shoots, length of the three largest roots per cutting. It was conclude that, the protected environment with plastic cover on sand as substrate must recommended for the rooting of fig estaca, collecting them in the first half of July. The inclination position and cutting depth of the estaca and the substrate coverage with plastic mulching did not influence the results.
Resumo:
ABSTRACT The objective of the present study was to evaluate the effect of nitrogen doses applied via fertigation and associated with different types of crop establishment fertilization on growth and biomass of radish. The experiment was conducted in a greenhouse of the Academic Unit of Agricultural Engineering, Federal University of Campina Grande, from April to May 2014. Treatments consisted of five doses of nitrogen fertilizer applied by fertigation (0, 0.7, 1.4, 2.1 and 2.8g per pot) and three types of crop establishment fertilization (humus 2:2; NPK and control), arranged in a 5 x 3 factor design with four repetitions. The 15 treatments were arranged in 60 plots. The nitrogen source used in the study was urea, divided in three applications: the first application was carried out eight days after transplanting, the second, on day 15, and the third, on day 22. The crop establishment fertilization significantly influenced the growth variables and plant mass of the radish on day 35 after transplanting. The highest values of the variables (number of leaves, plant height, bulb diameter, leaf area, fresh mass of the aerial part, dry mass of the aerial part and root/aerial part were observed in the treatment with humus on day 35 after transplanting. The dose of 2.8g nitrogen per pot corresponding to 6.22g of urea per plant provided the highest yield for the variable number of leafs, leaf area and root length on day 35 after transplanting.
Resumo:
The expressions Management and Organization Studies and Management and Organization Knowledge are expressions of an Anglo-Saxon construct. The association of Organization Studies (OS) with Management (M) produces the subordination of the former to the latter. In a different direction, a critical approach elaborated in Brazilian OS provides an original body of knowledge that expresses an anti-management (A-M) attitude. As the Brazilian A-M authors point out, the distinction between North/South M is irrelevant; what is relevant is a coherent pluriversal A-M attitude. In this paper, we honor and disseminate the Brazilian original body of knowledge on OS and introduce an OS agenda that is liberated from M.
Resumo:
In this paper, two wind turbines equipped with a permanent magnet synchronous generator (PMSG) and respectively with a two-level or a multilevel converter are simulated in order to access the malfunction transient performance. Three different drive train mass models, respectively, one, two and three mass models, are considered in order to model the bending flexibility of the blades. Moreover, a fractional-order control strategy is studied comparatively to a classical integer-order control strategy. Computer simulations are carried out, and conclusions about the total harmonic distortion (THD) of the electric current injected into the electric grid are in favor of the fractional-order control strategy.
Resumo:
Fine recycled aggregates are seen as the last choice in recycling for concrete production. Many references quote their detrimental influence on the most important characteristics of concrete: compressive and tensile strength; modulus of elasticity; water absorption; shrinkage: carbonation and chloride penetration. These two last characteristics are fundamental in terms of the long-term durability of reinforced or prestressed concrete. In the experimental research carried out at IST, part of which has already been published, different concrete mixes (with increasing rates of substitution of fine natural aggregates sand - with fine recycled aggregates from crushed concrete) were prepared and tested. The results were then compared with those for a reference concrete with exactly the same composition and grading curve, but with no recycled aggregates. This paper presents the main results of this research for water absorption by immersion and capillarity, chloride penetration (by means of the chloride migration coefficient), and carbonation resistance, drawing some conclusions on the feasibility of using this type of aggregate in structural concrete, while taking into account any ensuing obvious positive environmental impact.