946 resultados para Time in the peak
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Past studies into the roles of testosterone in birds have focused on species that occur in temperate regions. In such species, plasma testosterone levels are high during the establishment of territories in the spring and are associated with increased aggression. In contrast to most temperate species, tropical birds frequently defend territories year-round, during which time territoriality often occurs in a nonsexual context. The few studies that have been carried out on tropical birds show lower levels of circulating testosterone than occur in their temperate counterparts. In some year-round territorial tropical species, testosterone and aggression are dissociated, while in other species testosterone still plays a role in regulating aggression. This study examined the relationship between aggression and plasma testosterone levels in a year-round territorial, subtropical population of the buff-banded rail with characteristics typical of tropical species. Peak testosterone levels were substantially lower than those found in temperate species. Males displayed a seasonal peak in plasma testosterone level when their partners were most likely to be fertile. At other times, testosterone levels were mostly undetectable, despite year-round territoriality. We found that T levels increased with courtship behavior but showed no relationship with aggression, supporting the hypothesis that dissociation between testosterone and territoriality may be widespread among tropical avian taxa. (C) 2003 Elsevier Science (USA). All rights reserved.
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This work presents for the first time a systematic study on the optimization of the electrochemical cleaning time of a mercury film when it is used as a working electrode material in the analysis of toxic metals, such as Pb2+, used as model metal, in real samples by SWASV. The optimization study for the film’s cleaning time aimed at attaining a Pb2+ minimum value in the film after the re-oxidation step of the pre-concentrated metal, given the impossibility of complete removal of traces of the electroactive species from the film. This value was kept constant in each concentration range studied ensuring thus that all assays were performed in initial identical conditions. An assay performed on a synthetic sample was taken as reference. In it, given the absence of matrix effects, and after the electrochemical cleaning step, a direct proportionality was observed between the residual amounts of Pb2+ in the film (which for the cleaning time used was never completely removed) and Pb2+ concentration in the solution. This fact determined a high correlation between Pb2+ peak current and Pb2+ concentration which was not observed when real samples (tree leaves) were analyzed. This behavior may result from the presence of the interfering surfactants always present in real samples of complex matrix. Cleaning time optimization was performed for the following Pb2+ concentration ranges in the real samples of complex matrix: 0.006-0.020, 0.020-0.080, 0.060-0.200 and 0.100-0.600 ppb. As expected, in order to obtain identical levels of film’s cleaning efficiency, the need for longer cleaning times has been observed for higher concentrations. The optimized cleaning times for the concentration ranges under study were 120, 150, 180 e 300 s, respectively.
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Mortality from asthma has shown important variations over time in several countries. In Brazil, a mortality study performed in the 60s, covering the cities of S.Paulo and Ribeirão Preto, and other ten cities showed that S.Paulo presented the lowest death rate from asthma among of them all. It was decided to study the time trends of deaths from asthma and from the whole set of respiratory diseases from 1970 to 1992, in the population aged 15-34 yrs. old in the State of S.Paulo, as well as to compare them with those of other countries. Asthma mortality rates during the 23 years of observation since 1975, showed an oscillatory declining pattern with a peak of deaths in the initial years. The linearization of the curve allows the calculation of Pearson's correlation coefficient that was significantly negative, suggesting a decline in the mortality over this period, mainly in the 5-9 yrs. old and 30-34 yrs. old strata. The segmentation of data between the period of ICD-9, 1970 to 1978, and of ICD-9, 1979 and subsequent years, shows that there is stability within each period, in all age-groups, except for that of 5-9 yr. olds between 1970-1978. Comparing the rates of the population aged 15-34 yrs. old for the State of S. Paulo, Brazil, with trends observed in 14 other countries, an intermediate pattern for the first triennial period (1970-1972) as well as for the subsequent triennial periods, emerges. A prevalence study of asthma, a follow up program meant for using emergency rooms and a surveillance of deaths due to all respiratory diseases and specifically to asthma are strongly recommended.
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OBJECTIVE: Physical activity during pregnancy is a poorly investigated subject on population level. The study aimed to describe duration, type and frequency of leisure-time physical activity during pregnancy, and to explore its associated factors. METHODS: A population-based study was carried out during 2004 in Southern Brazil. A total of 4,471 mothers were interviewed soon after delivery. Physical activity was measured using a questionnaire, developed for the study. Results were obtained by Poisson regression. RESULTS: In the sample, 14.8% of women reported to engage in some type of physical activity prior to pregnancy and 12.9% during pregnancy. In the first trimester, 10.4% of all mothers engaged in some type of physical activity; 8.5% in the second trimester and 6.5% in the third trimester. Only 194 mothers (4.3%) were active during the whole pregnancy. In the adjusted analysis, leisure-time physical activity was positively associated with schooling, physical activity advice during prenatal care, and family income (p<0.001), being employed during pregnancy (p=0.05), and number of pregnancies (p=0.02). Walking was the most frequent activity. CONCLUSIONS: The prevalence of leisure-time physical activity is low among Brazilian pregnant women. Although physical activity is not perceived as being pregnancy-threatening, and current guidelines recommend it, this population's behavior does not seem to be changing. Active lifestyle for both pregnant women and future mothers should be encouraged.
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Contrastando com o importante legado dos mestres organistas portugueses dos séculos XVI e XVII, a música portuguesa para órgão pós-1700 parece quase inexistente (excluindo raros exemplos, como as quatro sonatas para órgão de Carlos Seixas). Seja devido à destruição causada pelo grande terramoto de Lisboa em 1755, ou a outras causas, a ausência de fontes é surpreendente, considerando os testemunhos de actividade musical durante aquele período. Este artigo lida com uma fonte até hoje relativamente ignorada: o manuscrito CLI/1-4 nº 7 da Biblioteca do Palácio Ducal de Vila Viçosa (Versos / Sobre o Canto Chão / Para Orgão / De Fr. Jeronimo da M.dre de DS.). Esta colecção de vinte versos para órgão de Jerónimo da Madre de Deus é, de longe, a maior obra portuguesa para órgão da primeira metade do século XVIII até hoje conhecida. Claramente pensadas para o órgão, estas curtas peças testemunham a transformação da escrita para tecla em Portugal durante o reinado de D. João V (nomeadamente através da absorção de influências italianas) e fornecem informações preciosas sobre o tipo de instrumento em que eram tocadas.
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In previous works we have proposed a hybrid wired/wireless PROFIBUS solution where the interconnection between the heterogeneous media was accomplished through bridge-like devices with wireless stations being able to move between different wireless cells. Additionally, we had also proposed a worst-case timing analysis assuming that stations were stationary. In this paper we advance these previous works by proposing a worst-case timing analysis for the system’s message streams considering the effect of inter-cell mobility.
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Modern factories are complex systems where advances in networking and information technologies are opening new ways towards higher efficiency. Such move is being driven by market rules with ever-increasing competition levels, in search for faster time-to-market, improved process yield, non-stop operations, flexible manufacturing and tighter supply-chain coupling. All these aims present a common requirement, i.e. a realtime flow of information, from the plant-floor up to the management, maintenance, suppliers and clients, to support accurate monitoring and control of the factory. This stresses the importance achieved by the communication infrastructure in modern manufacturing industry. This paper presents the authors view concerning the current trends in modern factory communication systems. It addresses the problems of seamlessly integrating different information flows with diverse requirements, mainly in terms of timeliness. In this aspect, the debate between event-triggered and time-triggered communication is revisited as well as the joint support for both types of traffic. Finally, a view of where factory communication systems are moving to is also presented, showing the impact of open and widely available technologies.
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Fieldbus networks aim at the interconnection of field devices such as sensors, actuators and small controllers. Therefore, they are an effective technology upon which Distributed Computer Controlled Systems (DCCS) can be built. DCCS impose strict timeliness requirements to the communication network. In essence, by timeliness requirements we mean that traffic must be sent and received within a bounded interval, otherwise a timing fault is said to occur. P-NET is a multi-master fieldbus standard based on a virtual token passing scheme. In P-NET each master is allowed to transmit only one message per token visit, which means that in the worst-case the communication response time could be derived considering that the token is fully utilised by all stations. However, such analysis can be proved to be quite pessimistic. In this paper we propose a more sophisticated P-NET timing analysis model, which considers the actual token utilisation by different masters. The major contribution of this model is to provide a less pessimistic, and thus more accurate, analysis for the evaluation of the worst-case communication response time in P-NET fieldbus networks.
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This paper proposes a global multiprocessor scheduling algorithm for the Linux kernel that combines the global EDF scheduler with a priority-aware work-stealing load balancing scheme, enabling parallel real-time tasks to be executed on more than one processor at a given time instant. We state that some priority inversion may actually be acceptable, provided it helps reduce contention, communication, synchronisation and coordination between parallel threads, while still guaranteeing the expected system’s predictability. Experimental results demonstrate the low scheduling overhead of the proposed approach comparatively to an existing real-time deadline-oriented scheduling class for the Linux kernel.
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Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Estatística e Gestão de Informação
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The objective was to study the secretory pattern, both basal and stimulated either by histamine (0.1 mg/kg) or pentagastrin (64 ug/kg) in eighteen Cebus apella monkeys chronically infected with different T. cruzi strains (CA1, n=10; Colombian, n=4 and Tulahuen, n=4) and to describe the morphological findings in the gastrointestinal tract in twelve infected (6 sacrificed and 6 spontaneously dead) and four healthy monkeys. All infected monkeys and 35 healthy ones were evaluated by contrast X-ray examination. No differences were observed in basal acid output between control and infected groups. Animals infected with the Tulahuen and Colombian strains showed significant lower values of peak acid output in response to histamine or pentagastrin (p<0.01 and p<0.05 respectively; "t" test) in comparison to the controls. Barium contrast studies showed enlargement and dilatation of the colon in three infected animals. Histopathological lesions were seen in 75% of the autopsied animals either in colon alone (33%) or both, in colon and esophagus (42%). The normal secretion observed in the CA1 infected group could be due to a lower virulence of the strain, a lower esophagic tropism or the necessity of a longer post-infection time to cause lesions.
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Presented at Work in Progress Session, IEEE Real-Time Systems Symposium (RTSS 2015). 1 to 3, Dec, 2015. San Antonio, U.S.A..
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Presented at Work in Progress Session, IEEE Real-Time Systems Symposium (RTSS 2015). 1 to 3, Dec, 2015. San Antonio, U.S.A..
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INTRODUCTION: A time series study of admissions, deaths and acute cases was conducted in order to evaluate the context of Chagas disease in Pernambuco. METHODS: Data reported to the Information Technology Department of the Brazilian National Health Service between 1980 and 2008 was collected for regions and Federal Units of Brazil; and microregions and municipalities of Pernambuco. Rates (per 100,000 inhabitants) of hospitalization, mortality and acute cases were calculated using a national hospital database (SIH), a national mortality database (SIM) and the national Information System for Notifiable Diseases (SINAN), respectively. RESULTS: The national average for Chagas disease admissions was 0.99 from 1995 to 2008. Pernambuco obtained a mean of 0.39 in the same period, with the highest rates being concentrated in the interior of the state. The state obtained a mean mortality rate of 1.56 between 1980 and 2007, which was lower than the national average (3.66). The mortality rate has tended to decline nationally, while it has remained relatively unchanged in Pernambuco. Interpolating national rates of admissions and deaths, mortality rates were higher than hospitalization rates between 1995 and 2007. The same occurred in Pernambuco, except for 2003. Between 2001 and 2006, rates for acute cases were 0.56 and 0.21 for Brazil and Pernambuco, respectively. CONCLUSIONS: Although a decrease in Chagas mortality has occurred in Brazil, the disease remains a serious public health problem, especially in the Northeast region. It is thus essential that medical care, prevention and control regarding Chagas disease be maintained and improved.