951 resultados para myocardial bridge
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Unlike their counterparts in Europe and America, the citizen organizations acting for the well-being of animals in Japan have not received scholarly attention. In this research, I explore the activities of twelve Japanese pro-animal organizations in Tokyo and Kansai area from the perspective of social movement and civil society studies. The concept of a ‘pro-animal organization’ is used to refer generally to the collectives promoting animal well-being. By using the collective action frame analysis and the three core framing tasks – diagnostic, prognostic, and motivational – as the primarily analytical tools, I explore the grievances, tactics, motivational means, constructions of agency and identity as well as framing of civil society articulated in the newsletters and the interviews of the twelve organizations I interviewed in Japan in 2010. As the frame construction is always done in relation to the social and political context, I study how the organizations construct their roles as civil society actors in relation to other actors, such as the state, and the idea of citizen activism. The deficiencies in the animal welfare law and lack of knowledge among the public are identified as the main grievances. The primary tactic to overcome these problems was to educate and inform the citizens and authorities, because most organizations lack the channels to influence politically. The audiences were mostly portrayed as either ignorant bystanders or potential adherents. In order to motivate people to join their cause and to enforce the motivation within the organization, the organizations emphasized their uniqueness, proved their efficiency, claimed credit and celebrated even small improvements. The organizations tended to create three different roles for citizen pro-organizations in civil society: reactive, apolitical and emphatic animal lovers concentrating on saving individual animals, proactive, educative bridge-builders seeking to establish equal collaborative relations with authorities, and corrective, supervising watchdogs demanding change in delinquencies offending animal rights. Based on the results of this research, I suggest that by studying how and why the different relations between civil society and the governing actors of the state are constructed, a more versatile approach to citizens’ activism in its context can be achieved.
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Japan has been a major actor in the field of development cooperation for five decades, even holding the title of largest donor of Official Development Assistance (ODA) during the 1990s. Financial flows, however, are subject to pre-existing paradigms that dictate both donor and recipient behaviour. In this respect Japan has been left wanting for more recognition. The dominance of the so called ‘Washington Consensus’ embodied in the International Monetary Fund (IMF) and the World Bank has long circumvented any indigenous approaches to development problems. The Tokyo International Conference on African Development (TICAD) is a development cooperation conference that Japan has hosted since 1993 every five years. As the main organizer of the conference Japan has opted for the leading position of African development. This has come in the wake of success in the Asian region where Japan has called attention to its role in the so called ‘Asian Miracle’ of fast growing economies. These aspirations have enabled Japan to try asserting itself as a major player in directing the course of global development discourse using historical narratives from both Asia and Africa. Over the years TICAD has evolved into a continuous process with ministerial and follow-up meetings in between conferences. Each conference has produced a declaration that stipulates the way the participants approach the question of African development. Although a multilateral framework, Japan has over the years made its presence more and more felt within the process. This research examines the way Japan approaches the paradigms of international development cooperation and tries to direct them in the context of the TICAD process. Supplementing these questions are inquiries concerning Japan’s foreign policy aspirations. The research shows that Japan has utilized the conference platform to contest other development actors and especially the dominant forces of the IMF and the World Bank in development discourse debate. Japan’s dominance of the process is evident in the narratives found in the conference documents. Relative success has come about by remaining consistent as shown by the acceptance of items from the TICAD agenda in other forums, such as the G8. But the emergence of new players such as China has changed the playing field, as they are engaging other developing countries from a more equal level.
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Artikkeli luettavissa osassa: Part 2. - ISBN 9789522163172(PDF). - Liitteenä työpaperi
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This study comprised 12 hearts of Wied´s black-tufted-ear marmoset, Callithrix kuhlii (Coimbra-Filho 1985), 6 with Wasting Marmoset Syndrome (WMS) and 6 non-affected. Biometry was performed after death. After necropsy, the hearts were weighed, dissected, fixed in 10% formalin solution (pH 7.2), and processed for optical microscopy at 5µm sections stained with Haematoxylin-Eosin. Quantitative analysis was performed by stereological techniques. The statistical differences between the biometrical and stereological parameters were assessed by the Mann-Whitney test. The morphometric results showed that WMS causes a significant reduction in body and cardiac weights, and also in the volume density of vessels in those animals. Further studies are necessary to understand some of the results shown here.
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Crack formation and growth in steel bridge structural elements may be due to loading oscillations. The welded elements are liable to internal discontinuities along welded joints and sensible to stress variations. The evaluation of the remaining life of a bridge is needed to make cost-effective decisions regarding inspection, repair, rehabilitation, and replacement. A steel beam model has been proposed to simulate crack openings due to cyclic loads. Two possible alternatives have been considered to model crack propagation, which the initial phase is based on the linear fracture mechanics. Then, the model is extended to take into account the elastoplastic fracture mechanic concepts. The natural frequency changes are directly related to moment of inertia variation and consequently to a reduction in the flexural stiffness of a steel beam. Thus, it is possible to adopt a nondestructive technique during steel bridge inspection to quantify the structure eigenvalue variation that will be used to localize the grown fracture. A damage detection algorithm is developed for the proposed model and the numerical results are compared with the solutions achieved by using another well know computer code.
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Presentation at the Nordic Perspectives on Open Access and Open Science seminar, Helsinki, October 15, 2013
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In this thesis, the main point of interest is the robust control of a DC/DC converter. The use of reactive components in the power conversion gives rise to dynamical effects in DC/DC converters and the dynamical effects of the converter mandates the use of active control. Active control uses measurements from the converter to correct errors present in the converter’s output. The controller needs to be able to perform in the presence of varying component values and different kinds of disturbances in loading and noises in measurements. Such a feature in control design is referred as robustness. This thesis also contains survey of general properties of DC/DC converters and their effects on control design. In this thesis, a linear robust control design method is studied. A robust controller is then designed and applied to the current control of a phase shifted full bridge converter. The experimental results are shown to match simulations.
Effects of exercise training on autonomic and myocardial dysfunction in streptozotocin-diabetic rats
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Several investigators have demonstrated that diabetes is associated with autonomic and myocardial dysfunction. Exercise training is an efficient non-pharmacological treatment for cardiac and metabolic diseases. The aim of the present study was to investigate the effects of exercise training on hemodynamic and autonomic diabetic dysfunction. After 1 week of diabetes induction (streptozotocin, 50 mg/kg, iv), male Wistar rats (222 ± 5 g, N = 18) were submitted to exercise training for 10 weeks on a treadmill. Arterial pressure signals were obtained and processed with a data acquisition system. Autonomic function and intrinsic heart rate were studied by injecting methylatropine and propranolol. Left ventricular function was assessed in hearts perfused in vitro by the Langendorff technique. Diabetes (D) bradycardia and hypotension (D: 279 ± 9 bpm and 91 ± 4 mmHg vs 315 ± 11 bpm and 111 ± 4 mmHg in controls, C) were attenuated by training (TD: 305 ± 7 bpm and 100 ± 4 mmHg). Vagal tonus was decreased in the diabetic groups and sympathetic tonus was similar in all animals. Intrinsic heart rate was lower in D (284 ± 11 bpm) compared to C and TD (390 ± 8 and 342 ± 14 bpm, respectively). Peak systolic pressure developed at different pressures was similar for all groups, but +dP/dt max was decreased and -dP/dt max was increased in D. In conclusion, exercise training reversed hypotension and bradycardia and improved myocardial function in diabetic rats. These changes represent an adaptive response to the demands of training, supporting a positive role of physical activity in the management of diabetes.
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It is well known that the responses to vasoactive kinin peptides are mediated through the activation of two receptors termed bradykinin receptor B1 (B1R) and B2 (B2R). The physiologically prominent B2R subtype has certainly been the subject of more intensive efforts in structure-function studies and physiological investigations. However, the B1R activated by a class of kinin metabolites has emerged as an important subject of investigation within the study of the kallikrein-kinin system (KKS). Its inducible character under stress and tissue injury is therefore a field of major interest. Although the KKS has been associated with cardiovascular regulation since its discovery at the beginning of the last century, less is known about the B1R and B2R regulation in cardiovascular diseases like hypertension, myocardial infarction (MI) and their complications. This mini-review will summarize our findings on B1R and B2R regulation after induction of MI using a rat model. We will develop the hypothesis that differences in the expression of these receptors may be associated with a dual pathway of the KKS in the complex mechanisms of myocardial remodeling.
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Ascending aorta coarctation was produced by a minimally invasive technique in rabbits. Animal mortality was 5%. Morphometric and hemodynamic parameters were evaluated. A parabiotically isolated heart model was used to assess the hemodynamic parameters. Left ventricular weight/body weight ratio and muscle area showed clear evidence of hypertrophy when compared to control. The hemodynamic changes in the isolated heart model suggested decreased diastolic and systolic function in the coarcted group. The present model produced hypertrophy with low mortality rates as a result of its less invasive nature.
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To compare the sensitivity of dipyridamole, dobutamine and pacing stress echocardiography for the detection of myocardial ischemia we produced a physiologically significant stenosis in the left circumflex artery of 14 open-chest dogs (range: 50 to 89% reduction in luminal diameter). In each study, dobutamine (5 to 40 µg kg-1 min-1 in 3-min stages) and pacing (20 bpm increments, each 2 min, up to 260 bpm) were performed randomly, and then followed by dipyridamole (up to 0.84 mg/kg over 10 min). The positivity of stress echocardiography tests was quantitatively determined by a significant (P<0.05) reduction of or failure to increase absolute and percent systolic wall thickening in the stenotic artery supplied wall, as compared to the opposite wall (areas related to the left anterior descending artery). Systolic and diastolic frozen images were analyzed off-line by two blinded observers in the control and stress conditions. The results showed that 1) the sensitivity of dobutamine, dipyridamole and pacing stress tests was 57, 57 and 36%, respectively; 2) in animals with positive tests, the mean percent change of wall thickening in left ventricular ischemic segments was larger in the pacing (-19 ± 11%) and dipyridamole (-18 ± 16%) tests as compared to dobutamine (-9 ± 6%) (P = 0.05), but a similar mean reduction of wall thickening was observed when this variable was normalized to a control left ventricular segment (area related to the left anterior descending artery) (pacing: -16 ± 7%; dipyridamole: -25 ± 16%; dobutamine: -26 ± 10%; not significant), and 3) a significant correlation was observed between magnitude of coronary stenosis and left ventricular segmental dysfunction induced by ischemia in dogs submitted to positive stress tests. We conclude that the dobutamine and dipyridamole stress tests showed identical sensitivities for the detection of myocardial ischemia in this one-vessel disease animal model with a wide range of left circumflex artery stenosis. The pacing stress test was less sensitive, but the difference was not statistically significant. The magnitude of segmental left ventricular dysfunction induced by ischemia was similar in all stress tests evaluated.
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The purpose of the present study was to examine myocardial antioxidant and oxidative stress changes in male and female rats in the presence of physiological sex hormone concentrations and after castration. Twenty-four 9-week-old Wistar rats were divided into four groups of 6 animals each: 1) sham-operated females, 2) castrated females, 3) sham-operated males, and 4) castrated males. When testosterone and estrogen levels were measured by radioimmunoassay, significant differences were observed between the castrated and control groups (both males and females), demonstrating the success of castration. Progesterone and catalase levels did not change in any group. Control male rats had higher levels of glutathione peroxidase (50%) and lower levels of superoxide dismutase (SOD, 14%) than females. Control females presented increased levels of SOD as compared to the other groups. After castration, SOD activity decreased by 29% in the female group and by 14% in the male group as compared to their respective controls. Lipid peroxidation (LPO) was assessed to evaluate oxidative damage to cardiac membranes by two different methods, i.e., TBARS and chemiluminescence. LPO was higher in male controls compared to female controls when evaluated by both methods, TBARS (360%) and chemiluminescence (46%). Castration induced a 200% increase in myocardial damage in females as determined by TBARS and a 20% increase as determined by chemiluminescence. In males, castration did not change LPO levels. These data suggest that estrogen may have an antioxidant role in heart muscle, while testosterone does not.
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Metabolic studies using the in vitro non-recirculating blood-perfused isolated heart model require large volumes of blood. The present study was designed to determine whether heterologous pig blood collected from a slaughterhouse can be used as perfusate for isolated pig hearts perfused under aerobic and constant reduced flow conditions. Eight isolated working pig hearts perfused for 90 min at a constant flow of 1.5 ml g-1 min-1 with non-recirculated blood diluted with Krebs-Henseleit bicarbonate buffer at a hematocrit of 23% were compared to eight hearts subjected to the same protocol but perfused only with Krebs-Henseleit bicarbonate buffer solution. Hearts were paced at 100 bpm and subjected to aerobic perfusion at 38ºC. Hearts were weighed before perfusion and at the end of the experiment and the results are reported as percent weight gain (mean ± SD). Comparisons between groups were performed by the Student t-test (P<0.05). After 90 min of perfusion with modified Krebs-Henseleit, perfused hearts presented a larger weight gain than blood-perfused hearts (39.34 ± 9.27 vs 23.13 ± 5.42%, P = 0.003). Left ventricular end-diastolic pressure was higher in the modified Krebs-Henseleit-perfused group than in the blood group (2.8 ± 0.4 vs 2.3 ± 0.3 mmHg, respectively, P = 0.01). We conclude that heterologous blood perfusion, by preserving a more physiological myocardial water content, is a better perfusion fluid than modified Krebs-Henseleit solution for quantitative studies of myocardial metabolism and heart function under ischemic conditions.
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It is recognized that an imbalance of the autonomic nervous system is involved in the genesis of ventricular arrhythmia and sudden death during myocardial ischemia. In the present study we investigated the effects of clonidine and rilmenidine, two centrally acting sympathomodulatory drugs, on an experimental model of centrally induced sympathetic hyperactivity in pentobarbital-anesthetized New Zealand albino rabbits of either sex (2-3 kg, N = 89). We also compared the effects of clonidine and rilmenidine with those of propranolol, a ß-blocker, known to induce protective cardiovascular effects in patients with ischemic heart disease. Central sympathetic stimulation was achieved by intracerebroventricular injection of the excitatory amino acid L-glutamate (10 µmol), associated with inhibition of nitric oxide synthesis with L-NAME (40 mg/kg, iv). Glutamate triggered ventricular arrhythmia and persistent ST-segment shifts in the ECG, indicating myocardial ischemia. The intracisternal administration of clonidine (1 µg/kg) and rilmenidine (30 µg/kg) or of a nonhypotensive dose of rilmenidine (3 µg/kg) decreased the incidence of myocardial ischemia (25, 14 and 25%, respectively, versus 60% in controls) and reduced the mortality rate from 40% to 0.0, 0.0 and 12%, respectively. The total number of ventricular premature beats per minute fell from 30 ± 9 in the control group to 7 ± 3, 6 ± 3 and 2 ± 2, respectively. Intravenous administration of clonidine (10 µg/kg), rilmenidine (300 µg/kg) or propranolol (500 µg/kg) elicited similar protective effects. We conclude that clonidine and rilmenidine present cardioprotective effects of central origin, which can be reproduced by propranolol, a lipophilic ß-blocking agent.