259 research outputs found

    Review of Spaceflight Dental Emergencies

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    All exploration class missions--extending beyond earth's orbit--differ from existing orbital missions by being of longer duration and often not having a means of evacuation. If an exploration mission extends beyond a year, then there will be a greater lapse since the crewmembers last terrestrial dental exams, which routinely occur each year. This increased time since professional dental care could increase the chance of a dental emergency such as intractable pain, dental decay requiring a temporary filling, crown replacement, exposed pulp, abscess, tooth avulsion, or toothache. Additionally, any dental emergency will have to be treated in-flight with available resources and personnel who may not have extensive training in dental care. Thus, dental emergencies are an important risk to assess in preparation for exploration missions

    Product development approach for a stabilized ambulance stretcher

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    The level of vibrations that a patient experiences during ambulance transport is often too high. The ambulance crew must take measures to reduce the effects of vibration. Currently, they do it by reducing the speed at which the ambulance transports the patients or by deviating from the shortest routes to routes that have better conditions for transport. The deviation in the route is required to avoid speed bumps, potholes and other obstacles that cause high vibration peaks. These vibrations are most severe in the vertical direction. The human body is most sensitive to vibrations in the range from 0.1 to 80 Hz, and it is within this range that the dominant vertical vibrations of an ambulance stretcher occur. The vibrations experienced can be reduced by placing an active stabilization unit in between the stretcher mattress and the legs of the stretcher. This active system performs vibration compensation in real time. The system is controlled with a data logger which collects the vibrational information from the road and transfers that data to the control system. The system is based on a spring-motor configuration. The springbased systems help to keep the mattress in position thereby reducing the effects of vibration and improving the comforts of patient transport. Since the stabilization unit increases the weight of the stretcher, currently this device cannot be employed for nonpowered stretchers. A business plan for the product launch is analyzed. The business plan provides the information to make this product market ready. A financial analysis is also performed to support the claims of the business plan. The business plan is focused on launching the stabilization device and then provides insight into developing stretcher solutions for the market.O nível de vibrações que um paciente experimenta durante o transporte de ambulância é muitas vezes demasiado elevado. O pessoal da ambulância tem que tomar medidas para reduzir os efeitos da vibração. Atualmente isso é feito reduzindo-se a velocidade com que a ambulância transporta os pacientes ou desviando-se das rotas mais curtas para as rotas que têm melhores condições de transporte. O desvio na rota precisa ser feito para evitar lombas, buracos e outros obstáculos que causam altos picos de vibração. Essas vibrações são mais severas na direção vertical. O corpo humano é mais sensível a vibrações na faixa de 0,1 a 80 Hz, e é dentro dessa faixa que ocorrem as vibrações verticais dominantes numa maca de ambulância. As vibrações no transporte de pacientes podem ser reduzidas colocando uma unidade de estabilização ativa entre o colchão da maca e a estrutura da maca. Este sistema ativo realiza a compensação de vibração em tempo real. O sistema é controlado por um processador de dados que coleta informações vibracionais da estrada e transfere esses dados para o sistema de controlo. O sistema atua através de uma solução dinâmica com um motor passo a passo. Os sistemas baseados em motores passo a passo ajudam a manter o colchão em posição, reduzindo assim os efeitos da vibração e melhorando o conforto do transporte do paciente. Como a unidade de estabilização aumenta o peso da maca, atualmente este dispositivo não pode ser empregado para macas não motorizadas. Com base na proposta de produto concebido, um plano de negócios para o lançamento do produto desenhado. O plano de negócios fornece as informações para preparar o lançamento deste novo produto no mercado. Também foi realizada uma análise financeira para validar os pressupostos do plano de negócios. O plano de negócios foi construído com o foco no lançamento do dispositivo de estabilização e, em seguida, pressupõem extensões assentes no posterior para o desenvolvimento de soluções de maca integral a colocar no mercado

    Pre-colonial warfare and long-run development in India

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    Time-Mortality Relationships for \u3ci\u3eTribolium castaneum\u3c/i\u3e (Coleoptera: Tenebrionidae) Life Stages Exposed to Elevated Temperatures

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    The use of elevated temperatures (≥40-60°C) or heat treatments for managing insects in food-processing facilities is a viable alternative to space fumigation with methyl bromide. Quantitative data are lacking on the responses of life stages of the red flour beetle, Tribolium castaneum (Herbst), an important pest of food-processing facilities worldwide, to elevated temperatures used during heat treatments. We determined time-mortality relationships for eggs, young (neonate) larvae, old larvae, pupae, and adults of T. castaneum, exposed to constant temperatures of 42, 46, 50, 54, 58, and 60°C. Generally, mortality of each stage increased with an increase in temperature and exposure time. Young larvae were the most heat-tolerant stage, especially at temperatures ≥50°C. Exposure for a minimum of 7.2 h at ≥50°C was required to kill 99% of young larvae, whereas the other stages required ≤1.8 h. Heat treatments that control young larvae should control all other stages of T. castaneum, and young larvae should be used as test insects to evaluate efficacy against T. castaneum during an actual facility heat treatment. These results provide the basis for successful use of elevated temperatures for management of T. castaneum life stages associated with food-processing facilities

    Probabilistic Analysis of the Median Rule: Asymptotics and Applications

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    The solution of integer optimization problems by relaxation methods consists of three parts. First, the discrete problem is converted into a continuous optimization problem, which is generally more tractable. Second, the relaxed problem is solved efficiently, yielding a optimal solution in the continuous space. Finally, an assignment procedure is used to map this solution to a suitable discrete solution. One heuristic - we call it the relaxation heuristic - that often guides the choice and design of assignment algorithms is: given a continuous optimal solution, the corresponding integer optimal solution is likely to be nearby (with respect to some well defined metric). Intuitively, this heuristic is reasonable for objective functions that are, say, Lipschitz functions. For such functions, an assignment algorithm might map the continuous optimal solution to the nearest feasible solution in the discrete space, in the hope that the discrete solution will be optimal as well. In this paper, we consider properties of a particular assignment algorithm known as the median rule. Define a binary vector to be balanced when the numbers of its 1 \u27s and 0\u27s differ at most by one. The median rule used to assign n-dimensional real vectors to n-dimensional balanced binary vectors, may be loosely described as follows: map the ith component of a real vector to a 0 or 1, depending on whether that component is smaller or greater than the median value of the vector components. We address two aspects of the median rule. The first result is that given a real vector, the median rule produces the closest balanced binary vector, with respect to any Schur-convex distance criteria. This includes several Minkowski norms, entropy measures, gauge functions etc. In this sense, the median rule optimally implements the relaxation heuristic. The second result addresses the issue of relaxation error. Though the median rule produces the nearest balanced integer solution to a given real vector, it is possible that this solution is sub-optimal, and the actual optimal solution is located elsewhere. The difference between the actual optimal cost and the cost of the solution obtained by the median rule is called the relaxation error. We consider the optimization of real valued, parametrized, multivariable Lipschitz functions where domains are the set of balanced binary vectors. Varying the parameters over the range of their values, we obtain an ensemble of such problems. Each problem instance in the ensemble has an optimal real cost, an integer cost, and an associated relaxation error. We establish upper bounds on the probability that the relaxation error is greater than a given threshold t. In general, these bounds depend on the random model being considered. These results have an immediate bearing on the important graph bisection width problem, which involves the minimization of a certain semidefinite quadratic cost function over balanced binary domains. This important problem arises in a variety of areas including load balancing, [11,16], storage management [22], distributed directories [15], and VLSI design [10]. The results obtained indicate that the median rule in a certain precise sense, is an optimal assignment procedure for this problem. The rest of the paper is organized as follows: In section 3, we prove the shortest distance properties of the median rule. In section 4, we introduce the concept of relaxation error and the Lipschitz bisection problem. Upper bounds on the relaxation error are obtained in Section 5. A discussion on these results is given in Section 6

    Putting Humpty-Dumpty together again: Reconstructing functions from their projections.

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    We present a problem decomposition approach to reduce neural net training times. The basic idea is to train neural nets in parallel on marginal distributions obtained from the original distribution (via projection), and then reconstruct the original table from the marginals (via a procedure similar to the join operator in database theory). A function is said to be reconstructible, if it may be recovered without error from its projections. Most distributions are non-reconstructible. The main result of this paper is the Reconstruction theorem, which enables non-reconstructible functions to be expressed in terms of reconstructible ones, and thus facilitates the application of decomposition methods

    Characterization of a Class of Sigmoid Functions with Applications to Neural Networks

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    Sigmoid functions, whose graphs are S-shaped curves, appear in a great variety of contexts, such as the transfer functions in many neural networks. Their ubiquity is no accident; these curves are the among the simplest non-linear curves, striking a graceful balance between linear and non-linear behavior

    Updates and Overview of Spaceflight Medical Support in Russia and Kazakhstan

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    This panel presents recent updates to and a comprehensive overview of the operational medical support provided to ISS crewmembers in Star City, Russia and Kazakhstan as part of UTMB/KBRwyle's Human Health & Performance contract. With the current Soyuz training flow, physician support is required for nominal training evolutions involving pressure changes or other potential physical risks detailed in this presentation. In addition, full-time physician presence in Star City helps to address the disparity in access to health care in these relatively remote practice areas, while also developing and maintaining relationships with host nation resources. A unique part of standard training in Russia also involves survival training in both winter and water environments; logistic details and medical impacts of each of these training scenarios will be discussed. Following support of a successful training flow, UTMB/KBRwyle's Star City Medical Support Group (SCMSG) is also responsible for configuring medical packs in support of Soyuz launches and landings; we will present the rationale for current pack contents within the context of specific operational needs. With respect to contingency events, the group will describe their preparedness to respond appropriately by activating both local and global resources as necessary, detailing a specialized subset of the group who continually work and update these assets, given changes in international infrastructure and other impacts

    The Columbian exchange and conflict in Asia

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    Expression of renal aquaporins 1, 2, and 3 in a rat model of cisplatin-induced polyuria

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    Expression of renal aquaporins 1, 2, and 3 in a rat model of cisplatin-induced polyuria.BackgroundCisplatin (CP)-induced polyuria in rats is attributed to decreased medullary hypertonicity and/or an end-organ resistance to vasopressin. However, the roles of renal aquaporins (AQPs) have not yet been explored.MethodsMale Sprague-Dawley rats (230 to 245 g) received either a single injection of CP (5 mg/kg, N = 4) or saline (N = 4) intraperitoneally five days before sacrifice. Urine, blood, and kidney samples were analyzed.ResultsPlatinum accumulated in the cortex and outer medulla of CP-treated rats (39.05 ± 7.50 and 36.48 ± 12.44 μg/g vs. 2.52 ± 0.43 and 1.87 ± 0.84 μg/g dry tissue in controls, respectively). Histologically, tubular damage and decreased AQP1 immunolabeling were detected in the S3 segment of proximal tubules. CP treatment caused 4.4- and 4.8-fold increases, respectively, in blood urea nitrogen and urine volume, and a 4.4-fold decrease in urine osmolality. Immunoblots showed that AQP2 and AQP3 were significantly reduced to 33 ± 10% (P < 0.001) and 69 ± 11% (P < 0.05), respectively, in the inner medulla of CP-treated rats. Immunocytochemical analysis showed a decrease in AQP2 labeling in the inner medulla of CP-treated rats. Northern hybridization revealed a 33 ± 11% (P < 0.002) decrease in AQP2 mRNA expression in the inner medulla of CP-treated rats. AQP1 protein expression levels were modestly (67 ± 7%, P = 0.057) and significantly (53 ± 13%, P < 0.007) decreased in outer and inner medullae, respectively, of CP-treated rats.ConclusionsCP-induced polyuria in rats is associated with a significant decrease in the expression of collecting duct (AQP2 and AQP3) and proximal nephron and microvascular (AQP1) water channels in the inner medulla
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