Variations in dynamic knee valgus and gluteus medius onset timing in non-athletic females related to hormonal changes during the menstrual cycle

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

Interação entre fatores visuais e olfativo em localização de recursos pela mosca-varejeira, Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae), em condições naturais

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

Influence of HVOF parameters on the corrosion and wear resistance of WC-Co coatings sprayed on AA7050 T7

Thermal spray WC-based coatings are widely used in the aircraft industry mainly for their resistance to wear, reworking and rebuilding operations and repair of worn components on landing gear, hydraulic cylinders, actuators, propeller hub assemblies, gas turbine engines, and so on. The aircraft industry is also trying to use thermal spray technology to replace electroplating coatings such as hard chromium. In the present work, WC-Co coatings were built up on an AA 7050 aluminum alloy using high velocity oxygen fuel (HVOF) technology and a liquid nitrogen cooling prototype system. The influence of the spray parameters (standard conditions, W19S, increasing the oxygen flux, W19H, and also increasing the carrier gas flux, W19F) on corrosion, friction, and abrasive wear resistance were also studied. The coatings were characterized using optical (OM) and scanning electron (SEM) microscopy, and X-ray diffraction (XRD). The friction and abrasive wear resistance of the coatings were studied using Rubber Wheel and Ball on Disk tests. The electrochemical studies were conducted using open-circuit potential (E(oc)) measurements and electrochemical impedance spectroscopy (EIS). Differences among coated samples were mainly related to the variation of the thermal spray parameters used during the spray process. No significant differences were observed in the wear resistance for the coatings studied, and all of them showed a wear rate around 10 times lower than that of the aluminum alloy. The results of mass loss and wear rate were interpreted considering different mechanisms. Comparing the different spray parameters, the oxygen flux (higher flame temperature) produced the sample which showed the highest corrosion resistance in aerated and unstirred 3.5% NaCl solution. Aluminum ions were detected on the surface almost immediately after the immersion of samples W19S and W19F in chloride solution, showing that the electrolyte reached the substrate and galvanic corrosion probably occurred. For sample W19H, aluminum ions were not detected even after 120 min of immersion in NaCl solution. (C) 2008 Elsevier B.V. All rights reserved.

Sport fishing in Cachoeira de Emas in Mogi-Guaçu River, State of São Paulo, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fishing resources in the rio Cuiabá basin, Pantanal do Mato Grosso, Brazil

O recurso pesqueiro da bacia do rio Cuiabá, um dos mais importantes tributários da bacia do Alto Paraguai, formadora do Pantanal, foi estudado a partir dos dados de desembarque de pescado obtidos no Mercado do Porto de Cuiabá, Mato Grosso, Brasil. São descritas a composição e procedência das capturas para os anos de 2000 e 2001. O rio Cuiabá é a fonte dominante de pescado para a cidade de Cuiabá, mas uma parte do pescado comercializado localmente é oriunda do rio Paraguai. Além disso, atualmente o pescado vem de regiões mais distantes da zona urbana. Constatou-se que a pesca incide basicamente sobre espécies migradoras. As principais espécies capturadas foram os pimelodídeos pintado -Pseudoplatystoma corruscans, cachara -Pseudoplatystoma fasciatum e jaú -Paulicea luetkeni e os caraciformes pacu -Piaractus mesopotamicus, piraputanga -Brycon microlepis, piavuçu -Leporinus macrocephalus e dourado -Salminus brasiliensis. Os grandes bagres (Pimelodidae) foram os responsáveis por 70% do pescado desembarcado no período de estudo, dentre os quais o pintado foi a espécie mais capturada. Os dados indicam que as capturas atuais estão bem aquém daquelas registradas no início da década de 80. Além disso, apesar do número e composição de espécies capturadas serem similares àqueles da década de 80, a distribuição da abundância mudou. Atualmente a pesca captura mais espécies carnívoras do que espécies de níveis tróficos inferiores. Estes achados não podem ser creditados somente a sobrepesca, mas parecem resultar de uma complexa interação entre degradação ambiental, mudanças na preferência de mercado e medidas legais restritivas à pesca.

Evaluation of shot peening on the fatigue strength of anodized Ti-6Al-4V alloy

The increasingly design requirements for modern engineering applications resulted in the development of new materials with improved mechanical properties. Low density, combined with excellent weight/strength ratio as well as corrosion resistance, make the titanium attractive for application in landing gears. Fatigue control is a fundamental parameter to be considered in the development of mechanical components. The aim of this research is to analyze the fatigue behavior of anodized Ti-6Al-4V alloy and the influence of shot peening pre treatment on the experimental data. Axial fatigue tests (R = 0.1) were performed, and a significant reduction in the fatigue strength of anodized Ti-6Al-4V was observed. The shot peening superficial treatment, which objective is to create a compressive residual stress field in the surface layers, showed efficiency to increase the fatigue life of anodized material. Experimental data were represented by S-N curves. Scanning electron microscopy technique (SEM) was used to observe crack origin sites.

Coating residual stress effects on fatigue performance of 7050-T7451 aluminum alloy

The tendency of the aircraft industry is to enhance customer value by improving performance and reducing environmental impact. In view of availability, aluminum alloys have a historically tendency to faster insertion due to their lower manufacturing and operated production infrastructure. In landing gear components, wear and corrosion control of many components is accomplished by surface treatments of chrome electroplating on steel or anodizing of aluminum. One of the most interesting environmentally safer and cleaner alternatives for the replacement of hard chrome plating or anodizing is tungsten carbide thermal spray coating, applied by the high velocity oxy fuel (HVOF) process. However, it was observed that residual stresses originating from these coatings reduce the fatigue strength of a component.An effective process as shot peening treatment, considered to improve the fatigue strength, pushes the crack sources beneath the surface in most of medium and high cycle cases, due to the compressive residual stress field induced. The objective of this research is to evaluate a tungsten carbide cobalt (WC-Co) coating applied by the high velocity oxy fuel (HVOF) process, used to replace anodizing. Anodic films were grown on 7050-T7451 aluminum alloy by sulfuric acid anodizing, chromic acid anodizing and hard anodizing. The influence on axial fatigue strength of anodic films grown on the aluminum alloy surface is to degrade the stress-life performance of the base material. Three groups of specimens were prepared and tested in axial fatigue to obtain S-N curves: base material, base material coated by HVOF and base material shot peened and coated.Experimental results revealed increase in the fatigue strength of Al 7050-T7451 alloy associated with the WC 17% Co coating. on the other hand, a reduction in fatigue life occurred in the shot peened and coated condition. Scanning electron microscopy technique and optical microscopy were used to observe crack origin sites, thickness and coating/substrate adhesion. (c) 2007 Elsevier B.V. All rights reserved.

Winged leaf-cutting ants on nuptial flights used as transport by Attacobius spiders for dispersal

1. Sexuals of a leaf-cutting ant, Atta bisphaerica Forel, left their nest for nuptial flights in October to December.2. When leaving a nest, 53 of the 479 winged sexuals (or alates) observed (11.1%) carried up to three inquiline spiders of Attacobius luederwaldti.3. Spiders exclusively selected winged sexuals, not workers, and preferred females, indicating their expectation of the stronger flight ability of females. Neither these sexuals nor workers that appeared out of the nest on flight days attempted to remove or attack spiders on the body of alates.4. New qucens landing from their nuptial flight did not carry spiders, indicating that the spiders had left the ants in the sky to be dispersed by wind.5. No spiders were found in more than 100 incipient nests, which were estimated to be 2-3 months old. This suggests that the spiders jumped off the alate during mid-flight and dispersed on the wind to inhabit larger nests.

Ativação muscular do quadril e do joelho em duas aterrissagens realizadas por atletas do sexo masculino

OBJETIVO: Comparar a atividade muscular antes e após o contato com o solo entre as aterrissagens unilateral (AU) e bilateral (AB) em atletas do sexo masculino. PARTICIPANTES: Quinze atletas masculinos de voleibol sem sinais e sintomas de lesões nas extremidades inferiores (13 ± 1 ano, 1,70 ± 0,12m, 60 ± 12kg). MENSURAÇÕES:Os participantes realizaram dois saltos verticais, aterrissando unilateralmente e bilateralmente. A atividade mioelétrica do reto femoral (RF), bíceps femoral (BF), adutores de quadril (AQ) e a relação BF/RF foram comparados entre as duas aterrissagens e entre as fases caracterizadas por 100ms antes (PRE) e 100ms após (POS) o contato com o solo. RESULTADOS: Em ambas as aterrissagens, a ativação do RF foi maior na fase POS em relação à PRE. Na comparação entre as aterrissagens dentro da mesma fase não encontramos diferenças estatísticas. Apesar de o BF não ter apresentado diferenças entre as fases PRE e POS em cada aterrissagem, sua ativação foi maior na AU. Os AQ apresentaram maior ativação na fase POS durante a AU, no entanto não houve diferenças quando comparadas as duas aterrissagens. A relação BF/RF apresentou valores maiores em ambas as aterrissagens na fase PRE. No entanto, não encontramos diferenças entre as aterrissagens. CONCLUSÃO: Os resultados sugerem que cada músculo apresenta um papel diferente durante a fase de aterrissagem em homens. Enquanto que o RF possui como principal função a frenagem da articulação do joelho e do movimento descendente, caracterizada pelo aumento da ativação na fase pós-contato, o BF parece atenuar a tensão articular do joelho em atividades de maior impacto, mantendo-se mais ativo durante todo o ciclo da AU. Já a maior ativação dos AQ após o contato com solo na AU evidencia a importância da região lombo-pélvica na estabilização pélvica em situações de grande instabilidade. Estudos futuros são necessários para determinar os efeitos da ativação muscular apresentada na imposição de cargas mecânicas potencialmente lesivas no joelho em atletas do sexo masculino.

Planejamento urbano e geração de empregos: A cidade de São Paulo (Brasil) nos anos 90

This paper attempts to show the convergence of principles between labor market politics and urban management, emphasizing it relationship with pro-market theories. Limits and possibilities of the application of this theoretical frame were investigated by examining the changes in both composition and stock of labor in three important business spaces in São Paulo: Central Area, Paulista Avenue and the new expansion front near Luiz Carlos Berrini and Águas Epraiadas avenues. Despite the claims of pro-market theoreticians, information provided by Labor Ministry showed that between 1996 and 2000, a re-arrangemenet of the workers contingent among the investigated areas occurred, instead of the expected growth. The favorable behavior registered in Berrini/ Águas Espraiadas, because of the bulky volume of investments, took place at the same time that a decrease of labor in the Downtown; meanwhile, in Paulista, a growth of the number of employees was observed, in spite of the landing less elevated of investments.

Avaliação estatística de métodos de poda aplicados em neurônios intermediários da rede neural MLP

There are several papers on pruning methods in the artificial neural networks area. However, with rare exceptions, none of them presents an appropriate statistical evaluation of such methods. In this article, we proved statistically the ability of some methods to reduce the number of neurons of the hidden layer of a multilayer perceptron neural network (MLP), and to maintain the same landing of classification error of the initial net. They are evaluated seven pruning methods. The experimental investigation was accomplished on five groups of generated data and in two groups of real data. Three variables were accompanied in the study: apparent classification error rate in the test group (REA); number of hidden neurons, obtained after the application of the pruning method; and number of training/retraining epochs, to evaluate the computational effort. The non-parametric Friedman's test was used to do the statistical analysis.

The significance and determination by image analysis of microcrack density in hard chromium plating

It is well known that the microcrack density is a fundamental parameter in hard chromium electroplating. The chemical and mechanical properties of this coating are widely dependent on its microcrack density. In this paper a simple image analysis procedure to determine microcrack density is presented in order to demonstrate it as a fundamental tool to estimate the fatigue, corrosion and wear behavior, as well as the residual stress field of a coated component. For this purpose, the image analysis procedure was carried out on two kinds of hard chromium plating - one called accelerated (high velocity of deposition and fluoride-free) and the other conventional (with fluoride). The coatings were applied on samples of AISI 4340 aeronautical steel, which is widely used in aircraft landing gear components. To characterize the practical significance of this study, the microcrack density results were related to the fatigue, wear and corrosion behavior from previous study and to the residual stress field in the coatings.

Tracking the fin trade: Genetic stock identification in western Atlantic scalloped hammerhead sharks Sphyrna lewini

Location or stock-specific landing data are necessary to improve management of shark stocks, especially those imperiled by overexploitation as a result of the international shark fin trade. In the current absence of catch monitoring directly at extraction sites, genetic stock identification of fins collected from major market supply chain endpoints offers an overlooked but potentially useful approach for tracing the fins back to their geographical, or stock of, origin. To demonstrate the feasibility of this approach, we used mitochondrial control region (mtCR) sequences to trace the broad geographical origin of 62 Hong Kong market-derived Sphyrna lewini fins. Of these fins 21% were derived from the western Atlantic, where this species is listed as 'Endangered' by the International Union for the Conservation of Nature (IUCN). We also show that S. lewini mtCR sequences are geographically segregated in the western Atlantic (overall ΦST = 0.74, n = 177 sharks), indicating that breeding females either remain close to, or home back to, their natal region for parturition. Mixed stock analysis simulations showed that it is possible to estimate the relative contributions of these mitochondrial stocks to fin mixtures in globally sourced trade hubs. These findings underscore the feasibility of using genetic stock identification to source market-derived shark fins to obtain essential and otherwise unavailable data on exploitation levels, and thus to productively inform stock assessment and management of S. lewini and potentially also of other fished shark species. © Inter-Research 2009.

Diferenças na cinemática entre dois tipos de aterrissagens em atletas de voleibol masculinos

Anterior cruciate ligament (ACL) injuries are common in sports. Studies investigating injury mechanisms have demonstrated that most injuries arise from landing tasks. Despite the demonstration of differences between male and female kinematics, there are no studies showing how males behave during different landing tasks. The objective of this study was to compare the angular and temporal kinematics of the lower limbs between two different landing tasks. Double leg and single leg landings were recorded in the frontal and sagittal plane in 15 male volleyball athletes by videogrammetry. Reduced hip and knee flexion and increased knee valgus were observed in the single leg landing task compared to the double leg landing task. No significant difference in landing time was observed between the two tasks. In conclusion, the results support the premise that lower limb kinematics change according to the task performed. Further studies are necessary to explore the impact of these kinematic differences on knee loading and to relate them to ACL injury mechanisms in men.

Influence of a preventive training program on lower limb kinematics and vertical jump height of male volleyball athletes

Objective: To examine the influence of a preventative training program (PTP) on sagittal plane kinematics during different landing tasks and vertical jump height (VJH) in males. Design: Six weeks prospective exercise intervention. Participants: Fifteen male volleyball athletes (13 ± 0.7 years, 1.70 ± 0.12 m, 60 ± 12 kg). Interventions: PTP consisting of plyometric, balance and core stability exercises three times per week for six weeks. Bilateral vertical jumps with double leg (DL) and single leg (SL) landings were performed to measure the effects of training. Main outcome measurements: Kinematics of the knee and hip before and after training and VJH attained during both tasks after training. The hypothesis was that the PTP would produce improvements in VJH, but would not generate great changes in biomechanical behavior. Results: The only change identified for the SL was the longest duration of landing, which represents the time spent from initial ground contact to maximum knee flexion, after training, while increased angular displacement of the knee was observed during DL. The training did not significantly alter the VJH in either the SL (difference: 2.7 cm) or the DL conditions (difference: 3.5 cm). Conclusions: Despite the PTP's effectiveness in inducing some changes in kinematics, the changes were specific for each task, which highlights the importance of the specificity and individuality in selecting prevention injury exercises. Despite the absence of significant increases in the VJH, the absolute differences after training showed increases corroborating with the findings of statistically powerful studies that compared the results with control groups. The results suggest that short-term PTPs in low risk young male volleyball athletes may enhance performance and induce changes in some kinematic parameters. © 2012 Elsevier Ltd.