913 resultados para Just in Time
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OBJECTIVES The goal of this study was to determine whether the cardiostimulant effects of the endogenous beta(1)-adrenergic receptor (AR) agonist, (-)-norepinephrine are modified by polymorphic (Serine49Glycine [Ser49Gly], Glycine389Arginine [Gly389Arg]) variants of beta(1)-ARs in the nonfailing adult human heart. BACKGROUND Human heart beta(1)-ARs perform a crucial role in mediating the cardiostimulant effects of (-)-norepinephrine. An understanding of the significance of Ser49Gly and Gly389Arg polymorphisms in the human heart is beginning to emerge, but not as yet in adult patients who have coronary artery disease (CAD). METHODS The potency and maximal effects of (-)-norepinephrine at beta(1)-ARs (in the presence of beta(2)-AR blockade with 50 nM ICI 118,551 [erythro-DL-1(7-methylindan-4-yloxy)-3-isopropylamino-butan-2-ol]) for changes in contractile force and shortening of contractile cycle duration were determined in human right atrium in vitro from 87 patients undergoing coronary artery bypass grafting who were taking beta-blockers before surgery. A smaller sample of patients (n = 20) not taking beta-blockers was also investigated. Genotyping for two beta(1)-AR polymorphisms (Ser49Gly and Gly389Arg) was determined from a sample of blood taken at the time of surgery. RESULTS (-)-Norepinephrine caused concentration-dependent increases in contractile force and reductions in time to reach peak force and time to reach 50% relaxation. There were no differences in the potency or maximal effects of (-)-norepinephrine in the right atrium from patients with different Ser49Gly and Gly389Arg polymorphisms. CONCLUSIONS The cardiostimulant effects of (-)-norepinephrine at beta(1)-ARs were conserved across Ser49Gly and Gly389Arg polymorphisms in the right atrium of nonfailing hearts from patients with CAD managed with or without beta-blockers. (C) 2002 by the American College of Cardiology Foundation.
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Work-related falls continues to be one of the leading causes of fatalities in the Australian construction industry, and the failure to use fall protection equipment, such as fall-arrest harnesses and arresting devices, has been found to be a contributing factor. In an attempt to gain an understanding of the issues surrounding the use of fallarrest harness systems by construction workers a study involving semi-structured interviews of 15 male construction workers was carried out at three construction sites. The majority of interviewees commented that there was discomfort in wearing a fall-arrest harness; that there were a number of problems when anchored via an arresting device; and that using a fall-arrest system reduced productivity. Most of the interviewees considered that they needed safety precautions against falls, and they expressed the view that workers’ attitudes towards safety depended critically upon their supervisors’ attitude towards safety. It was also found that workers were not trained in rescue procedures. Interviewees expressed concern that retrieval of a suspended worker may not be carried out in time to prevent the onset of suspension trauma. A number of issues were identified which require further research, such as, investigation into suspension trauma, harness and arresting device design, training provided to workers, and the provision for rescues.
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Este ensaio discute algumas leituras críticas de textos teóricos da área das ciências sociais e humanas sobre o estatuto de género em países asiáticos, tentando estabelecer quais as suas principais problemáticas e metodologias. Presta especial atenção à questão das vozes femininas silenciadas e das práticas ignoradas do quotidiano das mulheres, problematizando o que sucede – ou pode suceder – quando às mulheres é permitido não só possuir um espaço social próprio (“a room of their own”, para citar Virginia Woolf), mas também uma voz própria. Para Edward Said o conceito ocidental de orientalismo implicava uma concepção masculina particular do mundo, mais evidente em romances e diários de viagem, onde as mulheres eram geralmente criaturas da fantasia masculina de poder. Esta concepção masculina do mundo oriental tende a ser estática, construindo-se assim o estereótipo do “eterno oriental”. As mulheres, tal como o “oriental”, nunca falam de si mesmos, das suas verdadeiras emoções, desejos e histórias: têm de ser representados, alguém tem de falar por si. No âmbito deste estudo, analisam-se alguns processos ideológicos e retóricos através dos quais a identidade das mulheres é construída e representada, tanto pelas próprias mulheres, como por vozes substitutas. A etnografia, a antropologia, a historiografia, a ficção, a cultura popular, os media e todos os tipos de fontes textuais e visuais desempenham um papel de relevo na invenção e na reinvenção de antigas e de novas identidades femininas, e na circulação destas no tempo e no espaço.
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Group decision making plays an important role in organizations, especially in the present-day economy that demands high-quality, yet quick decisions. Group decision-support systems (GDSSs) are interactive computer-based environments that support concerted, coordinated team efforts toward the completion of joint tasks. The need for collaborative work in organizations has led to the development of a set of general collaborative computer-supported technologies and specific GDSSs that support distributed groups (in time and space) in various domains. However, each person is unique and has different reactions to various arguments. Many times a disagreement arises because of the way we began arguing, not because of the content itself. Nevertheless, emotion, mood, and personality factors have not yet been addressed in GDSSs, despite how strongly they influence results. Our group’s previous work considered the roles that emotion and mood play in decision making. In this article, we reformulate these factors and include personality as well. Thus, this work incorporates personality, emotion, and mood in the negotiation process of an argumentbased group decision-making process. Our main goal in this work is to improve the negotiation process through argumentation using the affective characteristics of the involved participants. Each participant agent represents a group decision member. This representation lets us simulate people with different personalities. The discussion process between group members (agents) is made through the exchange of persuasive arguments. Although our multiagent architecture model4 includes two types of agents—the facilitator and the participant— this article focuses on the emotional, personality, and argumentation components of the participant agent.
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Relatório de Estágio apresentado à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Enisno do 1.º e 2.º Ciclo do Ensino Básico
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Resumo I – Prática Pedagógica. No início da aula de contrabaixo pergunta-se: «queres tocar em pé ou sentado?» É uma pergunta que poucos professores fazem, não só porque exige que o aluno saiba tocar das duas maneiras, mas principalmente porque cada professor tem a sua escola e opta por uma forma de ensinar, que acha que é a melhor para o aluno. Será mais conveniente dar a escolher ou determinar a posição com que o aluno vai tocar? Neste trabalho, procuram-se as respostas, analisando as várias posturas que se podem ensinar quando se toca contrabaixo. Começando pela questão elementar de estar sentado ou em pé e passando pelos vários detalhes que determinam o posicionamento do aluno em relação ao instrumento, como por exemplo, a altura a que se põe o instrumento ou a forma de apoio dos pés, acaba-se por fazer uma reflexão sobre a melhor forma de ensinar nos dias de hoje. A prática pedagógica deste ano letivo de estágio, consiste concretamente na observação das posturas adotadas por três alunos em particular. Foram ensinadas novas posturas a dois alunos e aperfeiçoadas as posturas já ensinadas a uma terceira aluna. Os resultados finais foram reveladores para a investigação que foi feita em simultâneo.
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Compositional real-time scheduling clearly requires that ”normal” real-time scheduling challenges are addressed but challenges intrinsic to compositionality must be addressed as well, in particular: (i) how should interfaces be described? and (ii) how should numerical values be assigned to parameters constituting the interfaces? The real-time systems community has traditionally used narrow interfaces for describing a component (for example, a utilization/bandwidthlike metric and the distribution of this bandwidth in time). In this paper, we introduce the concept of competitive ratio of an interface and show that typical narrow interfaces cause poor performance for scheduling constrained-deadline sporadic tasks (competitive ratio is infinite). Therefore, we explore more expressive interfaces; in particular a class called medium-wide interfaces. For this class, we propose an interface type and show how the parameters of the interface should be selected. We also prove that this interface is 8-competitive.
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We use the term Cyber-Physical Systems to refer to large-scale distributed sensor systems. Locating the geographic coordinates of objects of interest is an important problemin such systems. We present a new distributed approach to localize objects and events of interest in time complexity independent of number of nodes.
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The objective of this article is to provide additional knowledge to the discussion of long-term memory, leaning over the behavior of the main Portuguese stock index. The first four moments are calculated using time windows of increasing size and sliding time windows of fixed size equal to 50 days and suggest that daily returns are non-ergodic and non-stationary. Seeming that the series is best described by a fractional Brownian motion approach, we use the rescaled-range analysis (R/S) and the detrended fluctuation analysis (DFA). The findings indicate evidence of long term memory in the form of persistence. This evidence of fractal structure suggests that the market is subject to greater predictability and contradicts the efficient market hypothesis in its weak form. This raises issues regarding theoretical modeling of asset pricing. In addition, we carried out a more localized (in time) study to identify the evolution of the degree of long-term dependency over time using windows 200-days and 400-days. The results show a switching feature in the index, from persistent to anti-persistent, quite evident from 2010.
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The study of transient dynamical phenomena near bifurcation thresholds has attracted the interest of many researchers due to the relevance of bifurcations in different physical or biological systems. In the context of saddle-node bifurcations, where two or more fixed points collide annihilating each other, it is known that the dynamics can suffer the so-called delayed transition. This phenomenon emerges when the system spends a lot of time before reaching the remaining stable equilibrium, found after the bifurcation, because of the presence of a saddle-remnant in phase space. Some works have analytically tackled this phenomenon, especially in time-continuous dynamical systems, showing that the time delay, tau, scales according to an inverse square-root power law, tau similar to (mu-mu (c) )(-1/2), as the bifurcation parameter mu, is driven further away from its critical value, mu (c) . In this work, we first characterize analytically this scaling law using complex variable techniques for a family of one-dimensional maps, called the normal form for the saddle-node bifurcation. We then apply our general analytic results to a single-species ecological model with harvesting given by a unimodal map, characterizing the delayed transition and the scaling law arising due to the constant of harvesting. For both analyzed systems, we show that the numerical results are in perfect agreement with the analytical solutions we are providing. The procedure presented in this work can be used to characterize the scaling laws of one-dimensional discrete dynamical systems with saddle-node bifurcations.
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Prepared for presentation at the Portuguese Finance Network International Conference 2014, Vilamoura, Portugal, June 18-20
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Thesis submitted in the fulfillment of the requirements for the Degree of Master in Biomedical Engineering
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In the Yucatan Peninsula of Mexico, 95% of the human cases of Cutaneous Leishmaniasis are caused by Leishmania (Leishmania) mexicana with an incidence rate of 5.08 per 100,000 inhabitants. Transmission is limited to the winter months (November to March). One study on wild rodents has incriminated Ototylomys phyllotis and Peromyscus yucatanicus as primary reservoirs of L. (L.) mexicana in the focus of La Libertad, Campeche. In the present study, the prevalence of both infection and disease caused by L. (L.) mexicana in small terrestrial mammals were documented during five transmission seasons (1994-2004) in five foci of Leishmaniasis in the state of Campeche. Foci separated by only 100 km, with similar relative abundances of small mammals, were found to differ significantly in their prevalence of both symptoms and infection. Transmission rates and reservoir species seemed to change in space as well as in time which limited the implementation of effective control measures of the disease even in a small endemic area such as the south of the Yucatan Peninsula.