924 resultados para AVAILABILITY


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Cationic amino acid transporters (mCAT1 and mCAT2B) regulate the arginine availability in macrophages. How in the infected cell a pathogen can alter the arginine metabolism of the host remains to be understood. We reveal here a novel mechanism by which Salmonella exploit mCAT1 and mCAT2B to acquire host arginine towards its own intracellular growth within antigen presenting cells. We demonstrate that Salmonella infected bone marrow derived macrophages and dendritic cells show enhanced arginine uptake and increased expression of mCAT1 and mCAT2B. We show that the mCAT1 transporter is in close proximity to Salmonella containing vacuole (SCV) specifically by live intracellular Salmonella in order to access the macrophage cytosolic arginine pool. Further, Lysosome associated membrane protein 1, a marker of SCV, also was found to colocalize with mCAT1 in the Salmonella infected cell. The intra vacuolar Salmonella then acquire the host arginine via its own arginine transporter, ArgT for growth. The argT knockout strain was unable to acquire host arginine and was attenuated in growth in both macrophages and in mice model of infection. Together, these data reveal survival strategies by which virulent Salmonella adapt to the harsh conditions prevailing in the infected host cells.

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In this paper we have assessed the availability of land and the potential for biomass production in India to meet various demands for biomass, including modern bioenergy. This is estimated by considering the various demands on land and its suitability. The biomass production potential of energy plantations is assessed for different agroecological zones. The total woody biomass production is estimated to be 321 Mt, based on biomass productivity in the range 2 to 17 t/ha/yr for the different agro-ecological zones and considering the conservative estimate of 43 Mha land availability for biomass production. A surplus of 231 Mt of biomass (after meeting the increased demand for fuelwood and timber by the year 2010) is estimated to be available for energy, which has an electricity generation potential of 231 TWh. As a first step, only the feasible physical potential of biomass production is assessed, along with an analysis of barriers. The potential costs and benefits of biomass production strategy are not analysed. (C) 1999 Elsevier Science Ltd. All rights reserved.

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Interactions of major activities involved in airfleet operations, maintenance, and logistics are investigated in the framework of closed queuing networks with finite number of customers. The system is viewed at three levels, namely: operations at the flying-base, maintenance at the repair-depot, and logistics for subsystems and their interactions in achieving the system objectives. Several performance measures (eg, availability of aircraft at the flying-base, mean number of aircraft on ground at different stages of repair, use of repair facilities, and mean time an aircraft spends in various stages of repair) can easily be computed in this framework. At the subsystem level the quantities of interest are the unavailability (probability of stockout) of a spare and the duration of its unavailability. The repair-depot capability is affected by the unavailability of a spare which in turn, adversely affects the availability of aircraft at the flying-base level. Examples illustrate the utility of the proposed models.

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PurposeTo extend the previously developed temporally constrained reconstruction (TCR) algorithm to allow for real-time availability of three-dimensional (3D) temperature maps capable of monitoring MR-guided high intensity focused ultrasound applications. MethodsA real-time TCR (RT-TCR) algorithm is developed that only uses current and previously acquired undersampled k-space data from a 3D segmented EPI pulse sequence, with the image reconstruction done in a graphics processing unit implementation to overcome computation burden. Simulated and experimental data sets of HIFU heating are used to evaluate the performance of the RT-TCR algorithm. ResultsThe simulation studies demonstrate that the RT-TCR algorithm has subsecond reconstruction time and can accurately measure HIFU-induced temperature rises of 20 degrees C in 15 s for 3D volumes of 16 slices (RMSE = 0.1 degrees C), 24 slices (RMSE = 0.2 degrees C), and 32 slices (RMSE = 0.3 degrees C). Experimental results in ex vivo porcine muscle demonstrate that the RT-TCR approach can reconstruct temperature maps with 192 x 162 x 66 mm 3D volume coverage, 1.5 x 1.5 x 3.0 mm resolution, and 1.2-s scan time with an accuracy of 0.5 degrees C. ConclusionThe RT-TCR algorithm offers an approach to obtaining large coverage 3D temperature maps in real-time for monitoring MR-guided high intensity focused ultrasound treatments. Magn Reson Med 71:1394-1404, 2014. (c) 2013 Wiley Periodicals, Inc.

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Mycobacterium tuberculosis has the ability to persist within the host in a dormant stage. One important condition believed to contribute to dormancy is reduced access to oxygen known as hypoxia. However, the response of M. tuberculosis to such hypoxia condition is not fully characterized. Virtually all dormant models against tuberculosis tested in animals used laboratory strain H37Rv or Erdman strain. But major outbreaks of tuberculosis (TB) occur with the strains that have widely different genotypes and phenotypes compared to H37Rv. In this study, we used a custom oligonucleotide microarray to determine the overall transcriptional response of laboratory strain (H37Rv) and most prevalent clinical strains (S7 and S10) of M. tuberculosis from South India to hypoxia. Analysis of microarray results revealed that a total of 1161 genes were differentially regulated (>= 1.5 fold change) in H37Rv, among them 659 genes upregulated and 502 genes down regulated. Microarray data of clinical isolates showed that a total of 790 genes were differentially regulated in S7 among which 453 genes were upregulated and 337 down regulated. Interestingly, numerous genes were also differentially regulated in S10 (total 2805 genes) of which 1463 genes upregulated and 1342 genes down regulated during reduced oxygen condition (Wayne's model). One hundred and thirty-four genes were found common and upregulated among all three strains (H37Rv, S7, and S10) and can be targeted for drug/vaccine development against TB. (C) 2015 Published by Elsevier B.V.

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Distributed system has quite a lot of servers to attain increased availability of service and for fault tolerance. Balancing the load among these servers is an important task to achieve better performance. There are various hardware and software based load balancing solutions available. However there is always an overhead on Servers and the Load Balancer while communicating with each other and sharing their availability and the current load status information. Load balancer is always busy in listening to clients' request and redirecting them. It also needs to collect the servers' availability status frequently, to keep itself up-to-date. Servers are busy in not only providing service to clients but also sharing their current load information with load balancing algorithms. In this paper we have proposed and discussed the concept and system model for software based load balancer along with Availability-Checker and Load Reporters (LB-ACLRs) which reduces the overhead on server and the load balancer. We have also described the architectural components with their roles and responsibilities. We have presented a detailed analysis to show how our proposed Availability Checker significantly increases the performance of the system.

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Decisions concerning maintenance have become increasingly important and requires a diverse set of information as systems become more complex. The availability of information has an impact on the effectiveness of these decisions, and thus on the performance of the asset. This paper highlights the importance of quantifying the value of information on maintenance decisions and asset performance. In particular, we emphasise the need to focus on measuring value as opposed to cost of maintenance, which is the current practice. In this direction, we propose a measure - Value of Ownership (VOO) - to assess the value of information and performance of maintenance decisions throughout an assets lifecycle. © 2009 IFAC.

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The goal of this study was to test a technology that may help ensure a reliable and consistent supply of high quality and inexpensive clam seed to growers, thus fostering an emerging aquaculture industry by eliminating a seed shortage that limits sustainability. The overall objectives were to develop, test and demonstrate technical procedures and determine the financial feasibility of transferring remote setting technology from the Pacific Northwest molluscan shellfish industry to the hard clam aquaculture industry in Florida. (PDF has 44 pages.)

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Background: Budesonide has a long history as intranasal drug, with many marketed products. Efforts should be made to demonstrate the therapeutic equivalence and safety comparability between them. Given that systemic availability significantly varies from formulations, the clinical comparability of diverse products comes to be of clinical interest and a regulatory requirement. The aim of the present study was to compare the systemic availability, pharmacodynamic effect, and safety of two intranasal budesonide formulations for the treatment of rhinitis. Methods: Eighteen healthy volunteers participated in this randomised, controlled, crossover, clinical trial. On two separated days, subjects received a single dose of 512 mu g budesonide (4 puffs per nostril) from each of the assayed devices (Budesonida nasal 64 (R), Aldo-Union, Spain and Rhinocort 64 (R), AstraZeneca, Spain). Budesonide availability was determined by the measurement of budesonide plasma concentration. The pharmacodynamic effect on the hypothalamic-adrenal axis was evaluated as both plasma and urine cortisol levels. Adverse events were tabulated and described. Budesonide availability between formulations was compared by the calculation of 90% CI intervals of the ratios of the main pharmacokinetic parameters describing budesonide bioavailability. Plasma cortisol concentration-time curves were compared by means of a GLM for Repeated Measures. Urine cortisol excretion between formulations was compared through the Wilcoxon's test. Results: All the enroled volunteers successfully completed the study. Pharmacokinetic parameters were comparable in terms of AUC(t) (2.6 +/- 1.5 vs 2.2 +/- 0.7), AUCi (2.9 +/- 1.5 vs 2.4 +/- 0.7), t(max) (0.4 +/- 0.1 vs 0.4 +/- 0.2), C(max)/AUC(i) (0.3 +/- 0.1 vs 0.3 +/- 0.0), and MRT (5.0 +/- 1.4 vs 4.5 +/- 0.6), but not in the case of C(max) (0.9 +/- 0.3 vs 0.7 +/- 0.2) and t(1/2) (3.7 +/- 1.8 vs 2.9 +/- 0.4). The pharmacodynamic effects, measured as the effect over plasma and urine cortisol, were also comparables between both formulations. No severe adverse events were reported and tolerance was comparable between formulations. Conclusion: The systemic availability of intranasal budesonide was comparable for both formulations in terms of most pharmacokinetic parameters. The pharmacodynamic effect on hypothalamic-pituitary-adrenal axis was also similar. Side effects were scarce and equivalent between the two products. This methodology to compare different budesonide-containing devices is reliable and easy to perform, and should be recommended for similar products intented to be marketed or already on the market.

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The estimated potential of Nigerian fish resources is 1,830,994 tonnes(t) whereas the demand based on per capita consumption of 12.0kg and a population of 88.5 million is 1.085 million tonnes. Supply is presently less than 500,000 tons. The gap between demand and supply have to be met through improved utilization and increased availability of fish and fishery products. The role of fish in nutrition is recognized, since it supplies a good balance of protein, vitamins and minerals and a relatively low caloric content. This paper appraises the consumption and utilisation pattern of fish in Nigeria, the spoilage of fish and prevention of losses as a means of increasing the availability of fish for human consumption and consequent control of aggravated animal protein deficiency - induced malnutrition. The paper further highlights the point that without increased landings, increased supply of fish can be achieved through reduction of postharvest loss of what is presently caught. The use of newly designed smoke - drying equipment to achieve such goal is highlighted. The paper also emphasises the need to put into human food chain those non-conventional fishery resources and by-catch of shrimp and demersal trawl fishes by conversion into high value protein products like fish cakes, fish pies and salted dried cakes

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We investigated the feeding ecology of juvenile salmon during the critical early life-history stage of transition from shallow to deep marine waters by sampling two stations (190 m and 60 m deep) in a northeast Pacific fjord (Dabob Bay, WA) between May 1985 and October 1987. Four species of Pacific salmon—Oncorhynchus keta (chum) , O. tshawytscha (Chinook), O. gorbuscha (pink), and O. kisutch (coho)—were examined for stomach contents. Diets of these fishes varied temporally, spatially, and between species, but were dominated by insects, euphausiids, and decapod larvae. Zooplankton assemblages and dry weights differed between stations, and less so between years. Salmon often demonstrated strongly positive or negative selection for specific prey types: copepods were far more abundant in the zooplankton than in the diet, whereas Insecta, Araneae, Cephalapoda, Teleostei, and Ctenophora were more abundant in the diet than in the plankton. Overall diet overlap was highest for Chinook and coho salmon (mean=77.9%)—species that seldom were found together. Chum and Chinook salmon were found together the most frequently, but diet overlap was lower (38.8%) and zooplankton biomass was not correlated with their gut fullness (%body weight). Thus, despite occasional occurrences of significant diet overlap between salmon species, our results indicate that interspecific competition among juvenile salmon does not occur in Dabob Bay.