880 resultados para 090904 Navigation and Position Fixing


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Macrófitas são importantes produtoras primárias do ecossistema aquático, e o desequilíbrio do ambiente pode ocasionar seu crescimento acelerado. Portanto, levantamentos de dados relacionados a macrófitas submersas são importantes para contribuir na gestão de corpos de água. Contudo, a amostragem dessa vegetação requer um enorme esforço físico. Nesse sentido, a técnica hidroacústica é apropriada para o estudo de macrófitas submersas. Assim, os objetivos deste trabalho foram avaliar os tipos de dados gerados pelo ecobatímetro e analisar como esses dados caracterizam a vegetação. Utilizou-se o ecobatímetro BioSonics DT-X acoplado a um GPS. A área de estudo é um trecho do Rio Uberaba, MG. A amostragem foi feita por meio de transectos, navegando de uma margem à outra. Depois de processar os dados, obteve-se informação a respeito de ocorrência de macrófitas submersas, profundidade, altura média das plantas, porcentagem da cobertura vegetal e posição. A partir desse conjunto de dados, foi possível extrair outras duas métricas: biovolume e altura efetiva do dossel. Os dados foram importados de um Sistema de Informação Geográfica e geraram-se mapas ilustrativos das variáveis estudadas. Além disso, quatro perfis foram selecionados para analisar a diferença entre as grandezas de representação de macrófitas. O ecobatímetro mostrou-se uma ferramenta eficaz no mapeamento de macrófitas submersas. Cada uma das medidas - altura do dossel, ECH ou biovolume - caracteriza de forma diferente a vegetação submersa. Dessa forma, a escolha do tipo de representação depende da aplicação desejada.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Titanium alloys are excellent implant materials for orthopedic applications due to their desirable properties, such as good corrosion resistance, low elasticity modulus, and excellent biocompatibility. The presence of interstitial elements (such as oxygen and nitrogen) causes strong changes in the material's mechanical properties, mainly in its elastic properties. Study of the interaction among interstitial elements present in metals began with Snoek's postulate, that a stress-induced ordering of interstitials gives rise to a peak in the mechanical relaxation (internal friction) spectra. In the mechanical relaxation spectra, each species of interstitial solute atom gives rise to a distinct Snoek's peak, whose temperature and position depend on the measurement frequency. This effect is very interesting because its peculiar parameters are directly related to the diffusion coefficient (D) for the interstitial solute. This paper presents a study of diffusion of heavy interstitial elements in Ti-35Nb-7Zr-5Ta alloys using mechanical spectroscopy. Pre-exponential factors and activation energies are calculated for oxygen and nitrogen in theses alloys.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Natural selection shapes body and behavior of each species. For primates, the social environment constituted one of the greatest selective pressure for the development of their cognition. When we consider gender differences, we see that sexual selection also operates through different selective pressures for men and women not only in physical terms but in terms of cognitive skills. Among these, the primary cognitive abilities - that emerge naturally - and secondary - that rely on an artificial environment for learning - develop differently for each sex, making them suitable for specific tasks in different capacities. Previous studies utilized the Wason Selection Test a conditional logic tool - to measure, among several other things, the ability to recognize violation of rules in abstract contexts and social contexts. Subjects generally had better performance in the latter, however, in these studies possible differences motivated by learning in formal logic or genre were not considered. Our study investigated these two variables, as well as the time spent to solve each task. Furthermore, we used an index to take into account the rights and wrongs of the participants in tasks. We realized that although learning in formal logic does not bring significant differences in solving tests, the gender differences are strongly observed when we consider the social contexts and abstract. Women perform better in social tasks. This can be explained due to different sexual selective pressures for this gender in terms of one-on-one relationships within the group. Men are better at tasks of abstract context and this is probably due to the same reason. Their capabilities for territory defense, habitat navigation and forming coalitions depends on primary cognitive abilities that support secondary cognitive skills of abstraction. Thus, gender differences are a factor to be taken into account in controlling future experiments with the same tool

Relevância:

100.00% 100.00%

Publicador:

Resumo:

As plantas aquáticas são estudadas como um efeito do desequilíbrio causado pela poluição e/ou alagamento dos rios. A quantidade excessiva de plantas, conseqüente desse desequilíbrio, dificulta a navegação e a produção de energia elétrica. O objetivo deste trabalho foi identificar as principais plantas aquáticas do rio Tietê e relacioná-las com a turbidez da água dos diferentes reservatórios. Foram avaliados todos os focos de vegetação aquática emersa, flutuante e submersa, presentes em cada reservatório, em toda a sua extensão, sendo consideradas como importantes as espécies que apresentaram o caráter dominante. Foi observado que os represamentos apresentam problema de plantas aquáticas e a qualidade da infestação varia entre os reservatórios. Foram consideradas como dominantes as seguintes espécies: Brachiaria mutica, Brachiaria subquadripara, Eichhornia crassipes, Egeria densa, Egeria najas, Enidra sessilis e Typha angustifolia. Observou-se que houve uma tendência de maior ocorrência de plantas flutuantes e emersas (marginais) nos reservatórios com maior turbidez e de plantas submersas naqueles com menor turbidez. Para as duas braquiárias, observou-se que a freqüência das espécies aumentou com o aumento da turbidez até o limite de 34,93 NTU. O aguapé ocorreu com altos índices de freqüência (acima de 50%) em todos os reservatórios do rio Tietê, independentemente das características da água. em se tratando das egérias, a freqüência das espécies aumentou gradativamente com a redução da turbidez e a taboa não apresentou uma relação com o índice estudado. A espécie E. sessilis se mostrou bastante dependente da qualidade da água, tendo sua freqüência aumentada com o aumento da turbidez.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Kangaroo Program was implemented in Brazil in 2000 through the Unified Health System (Sistema Único de Saúde SUS) sustained with a humanized rethoric of health care assistance. This program adopts the skin-to-skin contact contributing to the mother-infant bond, breastfeeding and promoting security in mother s care. The users of SUS are encouraged to live in the maternity ward to follow the baby health improvement. However, it was verified in previous observations that mothers participation in the Kangaroo Program has been done through an imposed practice. Therefore, this study intended to understand the texts that permeate the kangaroo practice. This research was developed through two studies: 1) an historic exploration of motherhood concept and an analysis of how the motherhood is presented in the official document that orients the program; 2) an analysis of institutional dynamic of Kangaroo Program, emphasizing the study about the health workers everyday practice, the mothers view about their life in the maternity wards, and the attendance practice. It is highlighted that the relation between this two studies allowed the comprehension abouthow the official discourses can influence the health workers behaviors and how their viewpoint and position can shape the everyday work in a public health program. This research, supported by Institutional Ethnography, considers that people s practices and experiences are socially organized and shaped by broad social forces. The discourse method was used in the documental analysis and in the analysis of qualitative data from empiric research. The research showed that the kangaroo program has been an excellent way to save resources and to improve some baby s biologic and psychological aspects. However, this program has failed to consider the social, economic and cultural complexity of mothers and the structural limitation of the health care system. The official document uses the economic and medical approach, following the hegemonic biomedical model and the life style of the people that don t use the public health system. Consequently, the program has not been successful because it is planned without people participation. On the other hand, it was verified that although some professionals are committed with their work, the mainly does not consider mothers participation as an active process, using the institutional power as a social control to keep mothers uninformed about the possibility to leave the maternity wards. As a result, the research also showed that mothers perceive the program as mandatory and not as option that can improve pleasure moments. It is, therefore, necessary to consider the complex social determinants of health that can increase mothers participation in the Kangaroo Program. Bringing these issues into debate can be a reflective exercise on citizenship and governance, allowing spaces for the improvement of public health programs

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The World Wide Web has been consolidated over the last years as a standard platform to provide software systems in the Internet. Nowadays, a great variety of user applications are available on the Web, varying from corporate applications to the banking domain, or from electronic commerce to the governmental domain. Given the quantity of information available and the quantity of users dealing with their services, many Web systems have sought to present recommendations of use as part of their functionalities, in order to let the users to have a better usage of the services available, based on their profile, history navigation and system use. In this context, this dissertation proposes the development of an agent-based framework that offers recommendations for users of Web systems. It involves the conception, design and implementation of an object-oriented framework. The framework agents can be plugged or unplugged in a non-invasive way in existing Web applications using aspect-oriented techniques. The framework is evaluated through its instantiation to three different Web systems

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Created on 3 december 1997, the REMPLAC (Program for Assessment of Mineral Potencial of the Continental Shelf), this porgram aimed to make the basic survey, systematic geological and geophysical continental shelf, detail, at an appropriate scale, sites geo-economic, and perform the analysis and evaluation of mineral deposits. The REMPLAC should continue the efforts of Global Recognition Program of the Brazilian Continental Margin REMAC closed in 1978, the operations Geophysical Sea (GEOMAR) developed by the Directorate of Hydrography and Navigation and the various initiatives of the Program of Marine Geology and Geophysics (PGGM). Despite the high interest on the Amazon platform, there is little information o their morphology and sediment characterization, and in order to fill this gap, the present work samples sedimentological point followed by seismic acquisition. And the studies were to characterize the possible area of interest as being directly influence by tides, which sediments are reworked throughout the platform featuring grain angle with sharp corners, and the carbonate content increases as it approaches the breakdown the platform, and the bodies found outside the foraminifera and mollusks. However, diverging with organic matter that reduces its concentration as it moves away from the coast. The seismic profiles do not get satisfactory results because of low visibility, however, to correlate with the spot samples, of sediment were possible morphological characterization of the area.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Many potent antimicrobial peptides also present hemolytic activity, an undesired collateral effect for the therapeutic application. Unlike other mastoparan peptides, Polybia-MP1 (IDWKKLLDAAKQIL), obtained from the venom of the social wasp Polybia paulista, is highly selective of bacterial cells. The study of its mechanism of action demonstrated that it permeates vesicles at a greater rate of leakage on the anionic over the zwitterionic, impaired by the presence of cholesterol or cardiolipin; its lytic activity is characterized by a threshold peptide to lipid molar ratio that depends on the phospholipid composition of the vesicles. At these particular threshold concentrations, the apparent average pore number is distinctive between anionic and zwitterionic vesicles, suggesting that pores are similarly formed depending on the ionic character of the bilayer. To prospect the molecular reasons for the strengthened selectivity in Polybia-MP1 and its absence in Mastoparan-X, MD simulations were carried out. Both peptides presented amphipathic alpha-helical structures, as previously observed in Circular Dichroism spectra, with important differences in the extension and stability of the helix; their backbone solvation analysis also indicate a different profile, suggesting that the selectivity of Polybia-MP1 is a consequence of the distribution of the charged and polar residues along the peptide helix, and on how the solvent molecules orient themselves according to these electrostatic interactions. We suggest that the lack of hemolytic activity of Polybia-MP1 is due to the presence and position of Asp residues that enable the equilibrium of electrostatic interactions and favor the preference for the more hydrophilic environment.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Maieta guianensis Aubl. and M. poeppigii Mart. ex. Triana (Melastomataceae) are among the most common myrmecophytic plants in the Amazonian forest understory. These myrmecophytes are colonized exclusively by the ants Pheidole minutula Mayr or Crematogaster sp. and usually host two other arthropods, the spider Faiditus subflavus Exline and Levi and the recently described stilt bug Jalysus ossesae Henry. In this study, the association between J ossesae and the myrmecophytic plants M. guianensis and M. poeppigii in an upland forest area in central Amazon, Brazil, is described. The presence of the stilt bugs on M. guianensis and M. poeppigii and on plants around these myrmecophytes was recorded in five transects. The number and position of the stilt bugs on the leaf surface (upper or lower) and leaf type (with or without domatia) of these myrmecophytes, as well as their behavioral acts, were recorded. Jalysus ossesae was found only on the myrmecophytic plants M. guianensis and M. poeppigii. The stilt bug occurred at similar frequencies on M. guianensis and M. poeppigii, and the number of leaves significantly influenced the presence and number of stilt bugs on these myrmecophytes. Feeding, agonistic interaction between males, and mating were observed. Our data indicate that J. ossesae uses the myrmecophytes M. guinanensis and M. poeppigii as reproductive and foraging sites.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We intend to analyse the constraint structure of Teleparallelism employing the Hamilton-Jacobi formalism for singular systems. This study is conducted without using an ADM 3+1 decomposition and without fixing time gauge condition. It can be verified that the field equations constitute an integrable system.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Foi realizada uma pesquisa visando a avaliação morfológica e o local de inserção dos frênulos labiais superiores e inferiores. A amostra foi constituída de 100 pacientes em condições sócio-econômicas semelhantes, tendo-se observado que o frênulo labial simples foi o mais prevalente, inserindo o superior na gengiva inserida e o inferior, na mucosa alveolar. A distância média da inserção, em relação à borda gengival livre, foi de 4,4 mm para o superior e de 5,6 mm para o inferior. Foi possível, nessas áreas, manter o controle clínico da placa bacteriana

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Cytogenetic studies of three species of the subfamily Glandulocaudinae showed that Mimagoniates microlepis presents 2n = 52 chromosomes (6M + 20SM + 18ST + 8A), Mimagoniates lateralis presents 2n = 52 chromosomes (6M + 20SM + 16ST + 10A) and Glandalocauda melanogenys presents 2n = 52 chromosomes (4M + 12SM + 22ST + 14A). The number of NOR-bearing chromosome pairs ranged from two to four. Differences in number and position of NORs at the species and population levels were detected, suggesting that several chromosome rearrangements occurred in the evolutionary process of this group. Some aspects related to the chromosome evolution of the Glandulocaudinae are discussed.