960 resultados para Free space communication


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Phenolic compounds are found in seaweed species together with other Substances presenting antioxidant activity. The objective of this work was to evaluate the antioxidant activity of the free phenolic acids (FPA) fraction from the seaweed Halimeda monile, and its activity to protect the expression of hepatic enzymes in rats, under experimental CCI(4) injury. The antioxidant activity was measured by the DPPH method. The FPA fraction (80 mg/kg, p.o.) was administered during 20 consecutive days to rats. The peroxidation was performed by thiobarbituric acid reactive substances (TBARS). The SOD and CAT enzymatic expressions were measured by RT/PCR. The histology technique was used to evaluate liver injuries. The expression of both, CAT and SOD genes, was more preserved by FPA. Only partial injury could be observed by histology in the liver of rats receiving FPA as compared with the control group; and CCI(4) administration induced 60% more peroxidation as compared with the rats receiving FPA. These data suggest that FPA could modulate the antioxidant enzymes and oxidative status in the liver through protection against adverse effects induced by chemical agents.

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Iron deficiency is a common nutritional disorder, affecting about 30% of the world population. Deficits in iron functional compartments have suppressive effects on the immune system. Environmental problems, age, and other nutrient deficiencies are some of the situations which make human studies difficult and warrant the use of animal models. This study aimed to investigate alterations in the immune system by inducing iron deficiency and promoting recuperation in a mouse model. Hemoglobin concentration, hematocrit, liver iron store, and flow cytometry analyses of cell-surface transferrin receptor (CD71) on peripheral blood and spleen CD4+ and CD8+ T lymphocyte were performed in the control (C) and the iron-deficient (ID) groups of animals at the beginning and end of the experiment. Hematological indices of C and ID mice were not different but the iron stores of ID mice were significantly reduced. Although T cell subsets were not altered, the percentage of T cells expressing CD71 was significantly increased by ID. The results suggest that iron deficiency induced by our experimental model would mimic the early events in the onset of anemia, where thymus atrophy is not enough to influence subset composition of T cells, which can still respond to iron deficiency by upregulating the expression of transferrin receptor.

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P>With the evidence showing the protection variability of bacille Calmette-Guerin, new potential vaccines for tuberculosis have been tested around the world. One of the general concerns in tuberculosis vaccine development is the possibility of priming the host immune system with prior exposure to environmental mycobacteria antigens, which can change the efficacy of subsequent vaccination. As there is a great homology between the species from Mycobacterium genera, the previous contact of experimental animals with environmental mycobacteria could sensitize the mice and, in this way, could influence subsequent vaccine research. The aim of our study was to investigate critical points in an animal facility to search for environmental mycobacteria that eventually could be in direct or indirect contact with the experimental animals. Samples were collected from surfaces of walls, floor, animal cages and shelves and analysed using the Ogawa-Kudoh decontamination method. Samples of drinking water, food and sawdust were collected for analysis by the NALC/NaOH decontamination method. Also, the samples were cultivated directly in broth medium, without any method for decontamination. After decontamination methods, we observed bacterial colony growth in 4.31% of the total of samples analysed. These samples were stained with Ziehl-Neelsen and we did not detect any acid-fast bacilli, suggesting that the animal facility analysed is free from contamination by environmental mycobacteria and is not a source of mycobacterial antigens. Furthermore, our study showed a new paradigm in tuberculosis vaccine development: concern about the animal facility environment in terms of immune system priming of experimental animals by nascent bacterial contaminants.

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This work evaluated the Modulation of reactive oxygen species (ROS) produced by the cisplatin-human DNA interaction in a cell-free experimental model by the carotenoids bixin and lycopene extracted from, natural dietary Sources and purified through luminol- and Cypridina luciferin methoxy-analogue (MCLA)- enhanced chemiluminescence assays. The results showed that the ROS generation by DNA-cisplatin interaction was inhibited by both lycopene and bixin in a concentration-dependent manner. At a concentration of 100 mu M, lycopene and bixin inhibited Superoxide anion (O center dot(2)) generation at 90% and 82%, respectively, and the total ROS generation at 44% and 42%, respectively. The formation of significant amounts of isomers or degradation products of both carotenoids was not observed after ROS scavenging, as evaluated by high-performance liquid chromatography. Taken together, these results Suggest that carotenoids can be helpful to Modulate the oxidative stress found in cancer therapy with cisplatin. (c) 2008 Elsevier Ltd. All rights reserved.

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The University of Queensland, Australia has developed Fez, a world-leading user-interface and management system for Fedora-based institutional repositories, which bridges the gap between a repository and users. Christiaan Kortekaas, Andrew Bennett and Keith Webster will review this open source software that gives institutions the power to create a comprehensive repository solution without the hassle..

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This study aims to provide some new understanding of the air-water flow properties in high-velocity water jets discharging past an abrupt drop. Such a setup has been little studied to date despite the relevance to bottom outlets. Downstream of the step brink, the free-jet entrains air at both upper and lower air-water interfaces, as well as along the sides. An air-water shear layer develops at the lower nappe interface. At the lower nappe, the velocity redistribution was successfully modelled and the velocity field was found to be similar to that in two-dimensional wake flow. The results highlighted further two distinct flow regions. Close to the brink (Wex < 5000), the flow was dominated by momentum transfer. Further downstream (Wex > 5000), a strong competition between air bubble diffusion and momentum exchanges took place.

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There is a morpheme 'li' in Mauritian Creole (MC), which is homophonous with the 3sg pronoun, and which, in the early creole, occurs frequently between the subject and the predicate in affirmative, present tense clauses. I propose that that 'li' may have originated as a resumptive pronoun, co-referential with the subject, but following the grammaticalization of new determiner elements to mark the semantic contrasts of [±definite] and singular vs. plural, 'li' has now grammaticalized into a predicate marker. Its presence is sensitive to both the nature of the predicate, and to the definiteness and specificity features of the subject NP. My analysis is within the framework of Truth Conditional Semantics, where indefinite NPs are analyzed as variables that get introduced into the discourse, and must be bound by an operator to yield a closed proposition, with a truth value. Drawing on a comparison with a cognative morpheme 'i' in Seychellois Creole, I claim that its path to grammaticalization is linked to that of the specificity marking 'la'.

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Using spontaneous parametric down-conversion, we produce polarization-entangled states of two photons and characterize them using two-photon tomography to measure the density matrix. A controllable decoherence is imposed on the states by passing the photons through thick, adjustable birefringent elements. When the system is subject to collective decoherence, one particular entangled state is seen to be decoherence-free, as predicted by theory. Such decoherence-free systems may have an important role for the future of quantum computation and information processing.

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The generalized Gibbs sampler (GGS) is a recently developed Markov chain Monte Carlo (MCMC) technique that enables Gibbs-like sampling of state spaces that lack a convenient representation in terms of a fixed coordinate system. This paper describes a new sampler, called the tree sampler, which uses the GGS to sample from a state space consisting of phylogenetic trees. The tree sampler is useful for a wide range of phylogenetic applications, including Bayesian, maximum likelihood, and maximum parsimony methods. A fast new algorithm to search for a maximum parsimony phylogeny is presented, using the tree sampler in the context of simulated annealing. The mathematics underlying the algorithm is explained and its time complexity is analyzed. The method is tested on two large data sets consisting of 123 sequences and 500 sequences, respectively. The new algorithm is shown to compare very favorably in terms of speed and accuracy to the program DNAPARS from the PHYLIP package.

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Classical mechanics is formulated in complex Hilbert space with the introduction of a commutative product of operators, an antisymmetric bracket and a quasidensity operator that is not positive definite. These are analogues of the star product, the Moyal bracket, and the Wigner function in the phase space formulation of quantum mechanics. Quantum mechanics is then viewed as a limiting form of classical mechanics, as Planck's constant approaches zero, rather than the other way around. The forms of semiquantum approximations to classical mechanics, analogous to semiclassical approximations to quantum mechanics, are indicated.

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Objective: A needs analysis was undertaken to determine the quality and effectiveness of mental health services to Indigenous consumers within a health district of Southern Queensland. The study focussed on identifying gaps in the service provision for Indigenous consumers. Tools and methodologies were developed to achieve this. Method: Data were collected through the distribution of questionnaires to the target populations: district health service staff and Indigenous consumers. Questionnaires were developed through consultation with the community and the Steering Committee in order to achieve culturally appropriate wording. Of prime importance was the adaptation of questionnaire language so it would be fully understood by Indigenous consumers. Both questionnaires were designed to provide a balanced perspective of current mental health service needs for Indigenous people within the mental health service. Results: Results suggest that existing mental health services do not adequately meet the needs of Indigenous people. Conclusions: Recommendations arising from this study indicate a need for better communication and genuine partnerships between the mental health service and Indigenous people that reflect respect of cultural heritage and recognises the importance of including Indigenous people in the design and management of mental health services. Attention to the recommendations from this study will help ensure a culturally appropriate and effective mental health service for Indigenous consumers.

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Free Zarb banner in Mayday procession in Brisbane, Australia 1969Truck has another banner Trades and Labor Council of Queensland and affiliated unions. Banner reads Free Zarb and other political prisoners - gaoled for refusing to kill, end conscription. Facade of KR Darling Downs building can be seen in the background.

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Power system real time security assessment is one of the fundamental modules of the electricity markets. Typically, when a contingency occurs, it is required that security assessment and enhancement module shall be ready for action within about 20 minutes’ time to meet the real time requirement. The recent California black out again highlighted the importance of system security. This paper proposed an approach for power system security assessment and enhancement based on the information provided from the pre-defined system parameter space. The proposed scheme opens up an efficient way for real time security assessment and enhancement in a competitive electricity market for single contingency case