Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-06-17T20:33:41Z No. of bitstreams: 1 joaopaulonogueiradarochasantos.pdf: 1586152 bytes, checksum: 0e5ee5c88539d1963c393a09d9431bea (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-13T14:40:45Z (GMT) No. of bitstreams: 1 joaopaulonogueiradarochasantos.pdf: 1586152 bytes, checksum: 0e5ee5c88539d1963c393a09d9431bea (MD5) / Made available in DSpace on 2016-07-13T14:40:45Z (GMT). No. of bitstreams: 1 joaopaulonogueiradarochasantos.pdf: 1586152 bytes, checksum: 0e5ee5c88539d1963c393a09d9431bea (MD5) Previous issue date: 2015-12-14 / A alteração de velocidade durante as provas de meio-fundo e fundo é conhecida como Estratégia de Ritmo (ER). No atletismo, as provas olímpicas (de adultos) têm a ER definidas. Na categoria mirim de atletismo (13 a 15 anos), pouco se sabe sobre a ER dos 1000 metros que é a distância máxima permitida na categoria pela Confederação Brasileira de Atletismo (CBAt). O objetivo do estudo foi caracterizar a ER utilizada por atletas mirins de atletismo na prova de 1000 m. A amostra foi composta por 82 atletas (41meninos e 41meninas) que concluíram a prova de 1000 m do Campeonato Brasileiro de Mirins de 2014, com média de idade de 14,33 ± 0,72 anos. Foi feita a filmagem da prova para cronometragem das parciais de 100 m. foram analisadas as variáveis velocidade e velocidade percentual em relação à velocidade máxima alcançada na prova (%Vmáx), os grupos foram divididos em sexo, idade, e desempenho na prova. Na análise dos dados gerais ficou evidente a estratégia parabólica “J Invertido”. Na análise por sexo, houve diferença significativa entre a velocidade de corrida, mas não houve no %Vmáx, indicando que não há diferença na estratégia de ritmo de meninas e meninos. Na análise por idade, a amostra foi dividida em dois grupos (13-14 anos e 15 anos), no sexo feminino não houve diferença significativa entre velocidade e %Vmáx nos dois grupos de idade, indicando que a ER foi semelhante entre as idades. No masculino, houve diferença significativamente maior no grupo dos meninos mais velhos tanto para velocidade quanto para o %Vmáx. Na comparação entre grupo de desempenho os atletas foram divididos em 3 grupos (≤14° lugar vs. 14°-28° lugar vs. >28° lugar), houve diferença significativamente maior do grupo dos melhores atletas em relação aos demais grupos tanto para velocidade quanto para %Vmáx, indicando que houve diferença na ER. Conclui-se que os atletas mirins adotam a estratégia Parabólica “J Invertido”. Há uma saída rápida nos 200 m iniciais da prova, uma fase de queda na velocidade até os 800 m, seguida da aceleração final. A queda da %Vmáx é maior nas meninas, nos meninos mais novos e nos atletas de menor desempenho. / The change of speed during the middle-distance and long-distance races is known as Pacing Strategy. In athletics, the Olympic track competitions have the PS defined, but in the adolescents athletes (13-15 years), there is a few knowledgement about the the PS of 1000 meters, which is the maximum distance allowed in the category by the Brazilian Athletics Confederation (CBAt) for this age. The aim of the study was to characterize the ER used by adolescents athletes in 1000 meters race. The sample was composed of 82 athletes (41 male and 41 female) who completed the race 1000 m of the Brazilian Championship 2014, with a mean age of 14.33 ± 0.72 years. The filming race was done to data analysis in 100 m sections. ".It was analyzed the following variables, averege speed for each section, and percentual speed related with the most speed through the 1000m running, for each section also (%Vmáx). The sample was divided into 3 groups, sex, age, and running performance. In the general data analysis was notorious the parabolic shaped strategy "inverted J. In the analysis by sex, there was a significant difference between running speed but not in Vmax%, indicating no difference in pacing strategy for female and male athletes. The analysis by age, were divided into two groups (13-14 years and 15 years), among female athletes there was no significant difference between speed and Vmax% in both age groups, indicating that the ER was similar in ages. In male athletes, there was a significant difference in the speed as much as %Vmáx between the two groups, indicating that the ER is different for both groups. The athletes were divided into 3 performance groups (≤14° place vs. 14th -28th place vs.> 28th place), matching the performance groups data, there was a higher significant difference for both speed and the Vmax% in the group 1, indicating that there were differences in ER. In conclusion, adolescents athletes (13-15 years) adopt parabolic shaped Strategy "inverted J". There is a fast start in the initial 200 meters of the race, a decrease of speed until 800 m, then the final acceleration. The %VMáx decrease phase is greater in girls, younger boys and lower performance athletes.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-09-27T13:51:40Z No. of bitstreams: 1 daniloleonelalves.pdf: 1042586 bytes, checksum: 995d86128bf6aced93c4541281efbfd1 (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-09-27T15:15:29Z (GMT) No. of bitstreams: 1 daniloleonelalves.pdf: 1042586 bytes, checksum: 995d86128bf6aced93c4541281efbfd1 (MD5) / Made available in DSpace on 2016-09-27T15:15:29Z (GMT). No. of bitstreams: 1 daniloleonelalves.pdf: 1042586 bytes, checksum: 995d86128bf6aced93c4541281efbfd1 (MD5) Previous issue date: 2016-07-04 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Conhecer a estratégia de ritmo (ER) em diferentes distâncias na marcha atlética tem-se mostrado apropriado para contornar problemas associados ao desempenho físico e a execução técnica dos movimentos. Partindo de três diferentes artigos, os objetivos deste trabalho são: 1) Descrever a estratégia de ritmo geral, em diferentes sexos, categorias, desempenhos obtidos e provas; 2) Verificar a associação das advertências com a velocidade em provas de marcha atlética; 3) Comparar a estratégia de ritmo planejada pelo atleta com a executada durante um evento competitivo de marcha atlética. Participaram 89 atletas (45 homens e 44 mulheres) de nível nacional e internacional, competidores na Copa Brasil de Marcha Atlética 2015, sendo distribuídos nas categorias sub 18, sub 20 e adulto. Dos 89 atletas participantes, 53 completaram a prova, 27 foram desclassificados e 9 abandonaram. Filmadoras digitais e cones foram posicionados a cada 10 % da distância total da prova, para a aquisição dos tempos parciais a fim de elaborar posteriormente as variações do ER de cada atleta. A ER foi dividida em três trechos, inicial (0% a 10% da distância total da prova), intermediária (10% a 90%) e final (90% a 100%) com a finalidade de verificar a alteração da velocidade entre estes trechos. Para a avaliação das advertências recebidas pelos atletas nas provas de marcha atlética, foram obtidas as súmulas das provas. Posteriormente, foi determinado em qual quilômetro da prova o atleta foi advertido e qual punição recebeu. Para a avaliação da estratégia planejada, um questionário com gráficos demonstrativos das principais curvas de ER existentes em provas de média e longa distância foi apresentado aos atletas antes do início da prova, e estes assinalavam qual estratégia planejou para a prova que iria disputar. Os resultados principais encontrados indicam que: 1) a ER em marchadores brasileiros seguiu um padrão positivo, no qual os atletas iniciam a competição em alta velocidade e diminuem progressivamente o ritmo até a linha de chegada. Não houve influência significativa dos fatores sexo ou desempenho obtido sobre a ER; 2) Os atletas recebem maior quantidade de advertências por ausência de bloqueio, sendo que estas concentraram-se entre as parciais 20% e 60% da prova. A velocidade mediana (Vmed) e a menor velocidade (Vmenor) observada ao longo da prova se correlacionaram com as advertências de ausência de bloqueio; 3) Observa-se que grande parte dos sujeitos planejaram estratégias constante ou negativa, porém, na análise da estratégia executada, constata-se que a maioria dos sujeitos realizou estratégia positiva. / Knowing the pacing strategy (PS) at different distances in race walking has been shown to be appropriate to outline problems associated with physical performance and the technical execution of the movements. Starting from three different articles, the objectives of this work are: 1) Describe the overall pace strategy in different genders, classes, performances in race walking; 2) Check the association of warnings with the speed in race walking tests; 3) Compare the pace strategy planned by the athlete to run during a competitive event race walking. Participated 89 athletes (45 men and 44 women) of national and international competitors in Brazil Cup Race Walking 2015 being distributed in the categories sub 18, sub 20 and adult. Of the 89 participating athletes, 53 finished the race, 27 were disqualified and 9 abandoned. Digital cameras and cones were positioned every 10% of the total distance of the race for the acquisition of split times in order to further elaborate the variations of PS of each athlete. The PS was divided into three sections, the initial (0% to 10% of the total distance of race), intermediate (10% to 90%) and final (90% to 100%) in order to verify the change of speed between these parts. For the evaluation of warnings received by athletes in tests of race walking, the dockets of the race were obtained. It was later determined that kilometer from the race the athlete was warned and what warning received. For the evaluation of the planned strategy, a questionnaire with graphs showing the main PS curves existing averaged medium and long distance was presented to the athletes before the start of the race, and they marked what strategy planned for race that would dispute. The main results indicate that: 1) the PS in Brazilian athletes followed a positive pattern in which athletes begin competition at high speed and gradually slow down until the finish line. There was no significant influence of gender factors or performance on ER; 2) The athletes are higher amount of bent knee, and these concentrated between the session 20% to 60% of the race. The average speed and the slower speed observed over the test correlated with the bent knee; 3) It is observed that most of the subjects planned constant or negative pacing strategy, however, the analysis of the executed strategy, it appears that most of the subjects made positive pacing strategy.

Orientador: Orlando Petrucci Junior / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T07:48:01Z (GMT). No. of bitstreams: 1 Assumpcao_AntonioCarlos_D.pdf: 13951044 bytes, checksum: 4ebd9040bcd7ea540e6927bdc4258384 (MD5) Previous issue date: 2013 / Resumo: Introdução: O aumento do limiar de estimulação ventricular (LEV) tem sido observado após a administração de choque elétrico de cardioversão/desfibrilação transtorácico (CDT) para desfibrilação ventricular, contudo, poucos estudos têm avaliado este fenômeno no que diz respeito à energia e a forma de onda empregada para a CDT. Este estudo analisou o LEV após CDT de 360J, comparando-se os resultados após aplicação de onda de energia Mono e Bi. Método: Em suínos Landrace femininos foram implantados sistema de estimulação permanente de marcapasso, divididos em três grupos: sem indução de fibrilação ventricular (FV) e CDT com formato de onda monofásica (Mono) e bifásica (Bi) (Grupo I); indução FV, um minuto de observação sem intervenção, dois minutos de massagem cardíaca externa, e CDT Mono e Bi (Grupo II) e indução de FV, dois minutos de observação sem intervenção, quatro minutos de massagem cardíaca externa e CDT Mono e Bi (Grupo III). Após CDT, o LEV foi avaliado a cada minuto durante dez minutos. Resultados: Um total de 143 experimentos foram concluídos. No final do período de observação, os grupos I e II mostraram valores constantes LEV. O Grupo III mostrou aumento no LEV Mono e Bi com energia externa, sem diferença entre os formatos de ondas externas. O formato Mono foi associada a valores mais elevados de LEV quando o tempo de parada cardiorrespiratória (PCR) foi maior, o que não foi verificado na Bi. Conclusão: A CDT não tem impacto significativo sobre o LEV. Com onda Mono, observou-se aumento do LEV quando o período de PCR foi mais longo / Abstract: Introduction. Although an increase in the ventricular pacing threshold (VPT) has been observed after administration of transthoracic shock for ventricular defibrillation, few studies have evaluated the phenomenon in respect to the defibrillation waveform energy. Therefore, this study examined the VPT behavior after transthoracic shock with a monophasic or biphasic energy waveform. Method. Domestic Landrace female piglets implanted with a permanent pacemaker stimulation system were divided into 3 groups: no ventricular fibrillation (VF) induction and transthoracic shock with monophasic or biphasic energy (group I); VF induction, 1 minute of observation without intervention, 2 minutes of external cardiac massage, and transthoracic shock with monophasic or biphasic energy (group II); and VF induction, 2 minutes of observation without intervention, 4 minutes of external cardiac massage, and transthoracic shock with monophasic or biphasic energy (group III). After external shock, the VPT was evaluated every minute for 10 minutes. Results. A total of 143 experiments were performed. At the end of the observation period, groups I and II showed steady VPT values. Group III showed an increase in VPT with monophasic or biphasic external energy, with no difference between the external energy sources. The monophasic but not the biphasic waveform was associated with higher VPT values when the VF was longer. Conclusion. Defibrillation does not have a significant impact on pacing threshold, but a longer VF period is related to a higher VPT after defibrillation with monophasic waveform / Doutorado / Fisiopatologia Cirúrgica / Doutor em Ciências

This study investigated the psychobiological and pacing characteristics of the 1.5 mile run. Sixty-six males (18-27 years) performed the run, and were monitored for ratings of perceived exertion, heart rate and split times. The perceived exertion values increased in a near-linear fashion inconsistent with other measures, and thus are not considered a supportable indicator of physiological performance during the run. Pace was characterized by an initial sprint that slowed to a near-steady pace and concluded with a final sprint. The initial and final sprints were most highly related to the variance of performance time. Initially, heart rate accelerated greatly. This acceleration slowed, ending in near-maximum heart rates. The data suggested that performance may rely heavily upon anaerobic mechanisms, and that variance in previously reported correlational analyses of VO2max and 1.5 mile run performance times may be somewhat due to anaerobic mechanisms.

In this study, lumped parameter cardiovascular modeling has been used to understand the influence of muscle properties on mechanical dyssynchrony (MD) as well as general muscle dynamics. Incorporating viscous influence into the model allowed for an expanded view when analyzing muscle parameter response to MD. A unique method of ventricle segmentation was introduced that allowed fast analysis of regional and global ventricular properties. This segmentation process produced a ventricle with four identical sections each consisting of separately tunable muscle properties in the form of minimum and maximum elastance, elastance waveform delay, and myocardial viscous friction, yet these regional sections remained globally dependent. Elastance waveform delay proved to be the most influential property on MD as measured by internal flow fraction (IFF), followed by regional elastance magnitude, and finally regional viscosity influence. Due to the unique segmentation of this model, two metrics for IFF were derived: (1) the "true" IFF (IFF-4seg) and (2) the IFF as would be measured by an ideal conductance catheter (IFF-CC). The results of IFF-CC versus IFF-4seg show that conductance catheters are not capable of measuring IFF during a side-to-side volume transfer within the stacked cylinder under measurement. Finally, unique energetic situations were observed with this model that point to likely myocardium remodeling situations.

The purpose of this study was to test the hypothesis that early-stage heart failure differentially affects the intrinsic cardiac nervous system's capacity to regulate cardiac function. After 2 wk of rapid ventricular pacing in nine anesthetized canines, cardiac and right atrial neuronal function were evaluated in situ in response to enhanced cardiac sensory inputs, stimulation of extracardiac autonomic efferent neuronal inputs, and close coronary arterial administration of neurochemicals that included nicotine. Right atrial neuronal intracellular electrophysiological properties were then evaluated in vitro in response to synaptic activation and nicotine. Intrinsic cardiac nicotine-sensitive, neuronally induced cardiac responses were also evaluated in eight sham-operated, unpaced animals. Two weeks of rapid ventricular pacing reduced the cardiac index by 54%. Intrinsic cardiac neurons of paced hearts maintained their cardiac mechano- and chemosensory transduction properties in vivo. They also responded normally to sympathetic and parasympathetic preganglionic efferent neuronal inputs, as well as to locally administered α- or β-adrenergic agonists or angiotensin II. The dose of nicotine needed to modify intrinsic cardiac neurons was 50 times greater in failure compared with normal preparations. That dose failed to alter monitored cardiovascular indexes in failing preparations. Phasic and accommodating neurons identified in vitro displayed altered intracellular membrane properties compared with control, including decreased membrane resistance, indicative of reduced excitability. Early-stage heart failure differentially affects the intrinsic cardiac nervous system's capacity to regulate cardiodynamics. While maintaining its capacity to transduce cardiac mechano- and chemosensory inputs, as well as inputs from extracardiac autonomic efferent neurons, intrinsic cardiac nicotine-sensitive, local-circuit neurons differentially remodel such that their capacity to influence cardiodynamics becomes obtunded.

Spinal cord stimulation (SCS) represents an acceptable treatment modality for patients with chronic angina pectoris refractory to standard therapy, but its mechanism of action remains unclear. To develop an experimental paradigm to study this issue, ameroid (AM) constrictors were implanted around the left circumflex coronary artery (LCx) in canines. Six weeks later, unipolar electrograms were recorded from 191 sites in the LCx territory in the open-chest, anesthetized state under basal pacing at 150 beats/min. We investigated the effect of SCS on ST segment displacements induced in the collateral-dependent myocardium in response to two stressors: (i) transient bouts of rapid ventricular pacing (TRP: 240/min for 1 min) and (ii) angiotensin II administered to right atrial neurons via their coronary artery blood supply. ST segment responses to TRP consisted of ST segment elevation in central areas of the LCx territory and ST depression at more peripheral areas. Such responses were unchanged when TRP was applied under SCS. Shortening of repolarization intervals in the metabolically compromised myocardium in response to TRP was also unaffected by SCS. In contrast, ST segment responses to intracoronary angiotensin II, which consisted of increased ST elevation, were attenuated by SCS in 6/8 preparations. The modulator effects of SCS were greatest at sites at which the greatest responses to angiotensin II occurred in the absence of SCS. These data indicate that spinal cord stimulation may attenuate the deleterious effects that stressors exert on the myocardium with reduced coronary reserve, particularly stressors associated with chemical activation of the intrinsic cardiac nervous system.

Introduction: Venoarterial extracorporeal membrane oxygenation (VA ECMO) is widely used in the treatment of circulatory failure, but repeatedly, its negative effects on the left ventricle (LV) have been observed. The purpose of this study is to assess the influence of ex- tracorporeal blood flow (EBF) on systemic hemodynamic changes and LV performance parameters during VA ECMO therapy of decompensated heart failure. Methods: Porcine models of low-output chronic and acute heart failure were developed by long-term fast cardiac pacing and coronary hypoxemia, respectively. Profound signs of circulatory decompensation were defined by reduced cardiac output and tissue hypoperfusion. Sub- sequently, under total anesthesia and artificial ventilation, VA ECMO was introduced. LV performance and organ specific parameters were recorded at different levels of EBF using an LV pressure-volume loop analysis, arterial flow probes on carotid and subclavian arteries, and transcutaneous probes positioned to measure cerebral and forelimb regional tissue oxygen saturations. Results: Conditions of severely decompensated heart failure led to systemic hypotension, low tissue and mixed venous oxygen saturations, and increase in LV end-diastolic pressure. By increasing the EBF from minimal flow to 5 L/min, we observed a...

In this small-scale qualitative study we examine PowerPoint presentations using cognitive perspectives (such as the Cognitive Theory of Multimedia Learning, Arousal theory, and Dual Channel processing) to compare teacher experience with a theoretical background. By analyzing collected PowerPoint presentations and interviewing the experienced teachers that created them about their didactic choices, we are able to identify and focus on four aspects of multimedia learning: Pacing, Student Stimuli, Signaling and Redundancy. Although the teachers involved in the study do not reference the cognitive perspective explicitly, we find similarities and differences between the teachers' near-practice experience and the underlying cognitive theories, finding pedagogical value in both their complementary and contradictory natures. From this, we suggest that the principles of cognitive theories from a scientific basis are complemented and tempered by the flexibility of experience.

Software testing, specifically in the medical device field, has become increasingly complex over the last decade. Technological enhancements to simulate clinical scenarios and advancements in communicating to medical devices have created the need for better testing strategies and methodologies. Typical medical device companies have depended on manual testing processes to fulfill Food and Drug Administration (FDA) submission requirements specifically Class III devices which are life supporting, life sustaining devices. At St. Jude Medical, software testing of Class III devices such as implantable cardioverter-defibrillators (ICDs), pacemakers, and pacing analyzers are given top priority to ensure the highest quality in each product. High emphasis is made on improving software testing for ease of use and for catching more software errors in each device. A significant stride in testing has automated the process and has provided software verification teams with the tools they need to successfully test and deliver high quality products. By creating software libraries which interact with communication to the other interfaces needed to test medical devices, test engineers can focus on fully testing device requirements and will not be concerned with how each test will interact with the device or any other testing tools. The main focus will be a specific St. Jude Medical device known as the Pacing System Analyzer (PSA). The PSA device will be used to demonstrate how verification engineers are able to benefit from software libraries and allow the testing process and test development to be fully automated. New technologies and standards will be created to simulate clinical scenarios and to communicate to new devices. The goal is to use software engineering principles to create standard test libraries which sustain these changes while still allowing testers to focus on finding issues for each device.