906 resultados para Time to exhaustion
Resumo:
Since 1989, NATO has expanded its strategic concept and geopolitical scope to the detriment of an efficient and well-defined military capability in Europe. The Ukrainian crisis has brought the attention back to Europe and to NATO’s deterrent value. As one of the Alliance’s leading members, Britain must act as a catalyst to ensure that NATO has the necessary military strength and political will to respond to the new security challenges.
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Maintenance planning of road pavement requires reliable estimates of roads’ lifetimes. In determining the lifetime of a road, this study combines maintenance activities and road condition measurements. The scope of the paper is to estimate lifetimes of road pavements in Sweden with time to event analysis. The model used includes effects of pavement type, road type, bearing capacity, road width, speed limit, stone size and climate zone, where the model is stratified according to traffic load. Among the nine analyzed pavement types, stone mastic had the longest expected lifetime, 32 percent longer than asphalt concrete. Among road types, ordinary roads with cable barriers had 30 percent shorter lifetime than ordinary roads. Increased speed lowered the lifetime, while increased stone size (up to 20 mm) and increased road width lengthened the lifetime. The results are of importance for life cycle cost analysis and road management.
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What motivates someone to dance until they are exhausted, sweaty, boiling hot and out of breath? I myself, recalling experiences when I have danced so hard I've nearly fainted, remember how exhilarating that motivation can be. But why? Why is that at all pleasant? Of course, I had several of my own explanations, but I was also interested in doing some scientific research on exhaustion. This question was of ample depth to become the basis of my project.
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O desenvolvimento da sociedade pós-industrial, voltada para a valorização da informação, exige das empresas um alto nível de adaptação às necessidades do consumidor, com o escopo de assegurar posição competitiva no mercado. A exposição do consumidor a novas tecnologias e a ciclos de vida útil, associados aos produtos progressivamente mais exíguos, exige das empresas a obrigatoriedade de introdução de velocidade nos processos de concepção e desenvolvimento de produtos. O presente trabalho propõe o estudo de caso de uma empresa da indústria de terminais celulares, mediante sua análise diante de um modelo descritivo de melhores práticas de geração de valor significativo, a partir da política de redução do time-to-market nas atividades de manufatura das empresas, embasada em profunda revisão bibliográfica sobre o tema. Assevera-se como a velocidade representa atributo constitutivo de vantagem competitiva e quais os recursos, atributos e ativos, a empresa deve constituir para assegurar o apropriado embasamento de uma política voltada para a redução dos ciclos de produção. A integração dos diversos elos da cadeia de valor apresenta essencialidade para a persecução do time-to-market, razão pela qual, outros dois aspectos são estudados com relativa profundidade. A terceirização autoriza a possibilidade da empresa se focar nas atividades consideradas primárias, delegando aos fornecedores o desempenho das atividades não-essenciais. Igualmente, destacam-se as principais conseqüências associadas a este processo. Não obstante, um segundo determinante da integração é alvo de avaliação, pela sua crescente representatividade no âmbito empresarial: a utilização da tecnologia de informação como estratégia para alavancagem dos negócios corporativos e integração dos parceiros diretamente envolvidos na fabricação dos produtos. O estudo pauta-se, fundamentalmente, na propositura de um modelo que pode ser adotado em qualquer empresa, com o escopo de se alcançar a vantagem competitiva sustentável.
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As neuroscience gains social traction and entices media attention, the notion that education has much to benefit from brain research becomes increasingly popular. However, it has been argued that the fundamental bridge toward education is cognitive psychology, not neuroscience. We discuss four specific cases in which neuroscience synergizes with other disciplines to serve education, ranging from very general physiological aspects of human learning such as nutrition, exercise and sleep, to brain architectures that shape the way we acquire language and reading, and neuroscience tools that increasingly allow the early detection of cognitive deficits, especially in preverbal infants. Neuroscience methods, tools and theoretical frameworks have broadened our understanding of the mind in a way that is highly relevant to educational practice. Although the bridge’s cement is still fresh, we argue why it is prime time to march over it.
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Increasing air movement over poultry by using fans (ventilation) has become an accepted means of reducing environmental heat stress over the last several years. The purpose of this study was to evaluate the effect of air velocity and exposure time to ventilation on body surface and rectal temperature of broiler chickens. Male broiler chickens aged 36-42 days were placed in individual wire cages and exposed to five different air velocities (5.7, 4.2, 3.1, 2.4, or 1.8 m/sec). Throughout the experiment head, back, leg, and rectal temperatures were monitored every 10 min during a 30-min period for each air velocity. The data showed that exposure time to the wind affected (P<.05) leg and body temperature, with a rapid reduction being observed during the first 10 min. There was a reduction in leg temperature with air velocity of 2 m/sec; however, air velocity lower than 4.5 m/sec was not effective in decreasing head and back temperature. The results suggest that air velocity of 2 m/sec, in air temperature of 29 degrees C, improves heat loss in the birds. The data also indicate that exposure time to ventilation seems to be a critical point in the maintenance of bird thermal homeostasis.
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Statement of problem. The use of ultrasonic tips has become an alternative for cavity preparation. However, there are concerns about this type of device, particularly with respect to intrapulpal temperatures and cavity preparation time.Purpose. The purpose of this study was to analyze pulpal temperature increases generated by an ultrasonic cavity preparation with chemical vapor deposition (CVD) tips, in comparison to preparation with a high-speed handpiece with a diamond rotary cutting instrument. The time required to complete the cavity preparation with each system was also evaluated.Material and methods. Thermocouples were positioned in the pulp chamber of 20 extracted human third molars. Slot-type cavities (3 x 3 x 2 mm) were prepared on the buccal and the lingual surfaces of each tooth. The test groups were: high-speed cavity preparation with diamond rotary cutting instruments (n = 20) and ultrasonic cavity preparation with CVD points (n = 20). During cavity preparation, the increases In pulpal temperature, and the time required for the preparation, were recorded and analyzed by Student's t test for paired samples (alpha = .05).Results. The average pulpal temperature increases were 4.3 degrees C for the high-speed preparation and 3.8 degrees C for the ultrasonic preparation, which were statistically similar (P = .052). However, significant differences were found (P < .001) for the time expended (3.3 minutes for the high-speed bur and 13.77 minutes for the ultrasound device).Conclusions. The intrapulpal temperatures produced during cavity preparation by ultrasonic tips versus high-speed bur preparation were similar. However, the use of the ultrasonic device required 4 times longer for the completion of a cavity preparation.
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O objetivo deste trabalho foi avaliar se a suplementação com LH ao final do tratamento gonadotrófico sincroniza o tempo das ovulações e incrementa a taxa de ovulação e produção de embriões em ovelhas Santa Inês. Vinte programas de superovulação (SOV) foram realizados em delineamento cross-over (intervalo de 60 dias). No D0, um CIDR foi inserido, sendo trocado por um novo sete dias após, quando 37,5µg de d-cloprostenol foram administradas. No D12, iniciou-se o tratamento com 256mg de pFSH em 8 administrações (12/12h). No D14, o CIDR foi retirado, 200UI de eCG e 37,5µg de d-cloprostenol foram administradas. No D15, as ovelhas foram alocadas em um dos dois grupos: Controle (n=10), sem suplementação com LH, e LH (n=10), tratado com 7,5mg de LH, 24h após a remoção do CIDR. Inseminações artificiais (IA) foram realizadas 42 e 48h após a remoção do CIDR. As estruturas ovarianas foram avaliadas por laparoscopia imediatamente antes de cada IA e 5 dias após, quando os embriões foram colhidos. As ovelhas que receberam o LH tiveram maior frequência de ovulações antes de 42h (P=0,05). O tratamento com LH tendeu em incrementar a frequência de CL e diminuir a de folículos anovulatórios (P=0,08). A suplementação com LH incrementou (P=0,05) a frequência de ovelhas com alta resposta superovulatória (≥11 CL; P=0,05). em conclusão, a suplementação com LH incrementou a frequência de ovelhas com alta resposta e ovulações antes de 42h depois da remoção do CIDR, entretanto, não houve sincronia entre as ovulações. A suplementação diminuiu a frequência de folículos anovulatórios, embora a taxa de ovulação e a produção de embriões permaneceram inalteradas.
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The purpose of this study was to evaluate the effect of using different mathematical models to describe the relationship between treadmill running speed and time to exhaustion. All models generated a value for an aerobic parameter (critical speed; S(critical)). 35 university students performed 5-7 constant-speed 0%-slope treadmill tests at speeds that elicited exhaustion in similar to 3 min to similar to 10 min. Speed and time data were fitted using 3 models: (1) a 2-parameter hyperbolic model; (2) a 3-parameter hyperbolic model; and (3) a hybrid 3-parameter hyperbolic + exponential model. The 2-parameter model generated values for S(critical) (mean (+/- SD): 186 +/- 33 m.min(-1)) and anaerobic distance capacity (ADC; 251 +/- 122 m) with a high level of statistical certainty (i.e., with small SEEs). The 3-parameter models generated parameter estimates that were unrealistic in magnitude and/or associated with large SEEs and little statistical certainty. Therefore, it was concluded that, for the range of exercise durations used in the present study, the 2-parameter model is preferred because it provides a parsimonious description of the relationship between velocity and time to fatigue, and it produces parameters of known physiological significance, with excellent confidence.
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Objective The purpose of this study was to identify the clinical factors associated with time to hCG remission among women with low-risk postmolar GTN. Methods This study included a non-concurrent cohort of 328 patients diagnosed with low-risk postmolar GTN according to FIGO 2002 criteria. Associations of time to hCG remission with history of prior mole, molar histology, time to persistence, use of D&C at persistence, presence of metastatic disease, FIGO score, hCG values at persistence, type of first line therapy and use of multiagent chemotherapy were investigated with both univariate and multivariate analyses. Results Overall median time to remission was 46 days. Ten percent of the patients required multi-agent chemotherapy to achieve hCG remission. Multivariate analysis incorporating the variables significant on univariate analysis confirmed that complete molar histology (HR 1.45), metastatic disease (HR 1.66), use of multi-agent therapy (HR 2.00) and FIGO score (HR 1.82) were associated with longer time to remission. There was a linear relationship between FIGO score and time to hCG remission. Each 1-point increment in FIGO score was associated with an average 17-day increase in hCG remission time (95% CI: 12.5-21.6). Conclusions Complete mole histology prior to GTN, presence of metastatic disease, use of multi-agent therapy and higher FIGO score were independent factors associated with longer time to hCG remission in low-risk GTN. Identifying the prognostic factors associated with time to remission and effective counseling may help improve treatment planning and reduce anxiety in patients and their families. © 2013 Elsevier Inc. All rights reserved.