An approach to guide a mobile robot from an initial position to a goal position avoiding any obst... more An approach to guide a mobile robot from an initial position to a goal position avoiding any obstacle in its path, when navigating in a semi-structured environment, is proposed in this paper. Such an approach, hereinafter referred to as tangential escape, consists in changing the current robot orientation through a suitable combination of the values of the angular and linear velocities (the control actions) whenever an obstacle is detected close to it. Then, the robot starts navigating in parallel to the tangent to the obstacle, regarding the point of the obstacle boundary the robot sensing system identifies as the closest one. The stability of the control system designed according this approach is proven, showing that the robot reaches any reachable goal, with or without a prescribed final orientation. Such a control system is programmed onboard a mobile platform whose sensing system is a laser scanner which provides 181 range measurements, for experimental validation. The results obtained are presented and discussed, allowing concluding that the tangential escape approach is able to guide the robot along trajectories that result in a reduction of the traveling time, thus saving batteries and reducing the motor wearing.
Estudos recentes (CHIVIACOWSKY & WULF, 2007) têm mostrado que a aprendizagem é realmente benefici... more Estudos recentes (CHIVIACOWSKY & WULF, 2007) têm mostrado que a aprendizagem é realmente beneficiada em adultos se, aos aprendizes, for fornecido "feedback" após "boas" tentativas em vez de após "más" tentativas. O presente estudo procurou examinar se o mesmo efeito pode ser observado em crianças. Foram utilizadas 40 crianças como sujeitos. Os participantes praticaram uma tarefa de arremessar saquinhos de feijão em um alvo, com a mão não-dominante, sem enxergar o alvo durante os arremessos. Todos os participantes receberam 50% de freqüência de conhecimento de resultados (CR), ou seja, em três tentativas em cada bloco de seis tentativas. Enquanto a um grupo foram fornecidos CRs para as três tentativas mais efetivas de cada bloco, a outro grupo foram fornecidos CRs para as três tentativas menos efetivas de cada bloco. A análise dos dados foi realizada através da ANOVA, utilizando-se o pacote estatístico SPSS. Discordando dos resultados encontrados em adultos, não foram verificadas diferenças significativas entre os grupos na fase de retenção.
Acta Obstetricia Et Gynecologica Scandinavica, 2010
Objective. To determine the risk of preeclampsia in a population with respect to maternal and sis... more Objective. To determine the risk of preeclampsia in a population with respect to maternal and sister histories of chronic hypertension, preeclampsia and eclampsia. Design. A case-control study of severe preeclampsia. Setting. Maternity hospital in Natal, Brazil. Participants. A total of 412 subjects were enrolled, 148 cases and 264 controls. Main outcome measures. Personal and familial histories of hypertensive disorders. Odds ratio estimates of preeclampsia with respect to family history of hypertensive diseases. Results. Women with a history of hypertensive disorders were more frequent in the case group (p = 0.001). Women whose mothers had a history of hypertension (p = 0.003), preeclampsia (p = 0.007) or eclampsia (p = 0.038) were at increased risk of severe preeclampsia. The risk of preeclampsia was greater when the woman had a sister with a history of hypertension (OR 2.60, 95% CI 1.60-4.21, p < 0.001), preeclampsia (OR 2.33, 95% CI 1.58-3.45, p < 0.001), or eclampsia (OR 2.57, 95% CI 1.28-5.16, p = 0.008). The risk of preeclampsia was also higher for women who had both a mother and sister with a history of hypertension (OR 3.65, 95% CI 1.65-8.09, p = 0.001). Conclusions. A family history of hypertensive disorders increased the risk of eclampsia and hemolysis elevated liver enzymes and low platelet (HELLP) syndrome in a Brazilian population.
American Journal of Obstetrics and Gynecology, 2006
Hepatic rupture HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome Preecl... more Hepatic rupture HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome Preeclampsia Hepatic artery ligation Objective: The purpose of this study was to review the management of hepatic rupture caused by HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome and to assess maternal and perinatal outcomes of these cases. Study design: A retrospective study of HELLP syndrome cases that were complicated by hepatic rupture was conducted. Results: Ten cases of hepatic rupture were identified. The median maternal age was 42.5 G 5.9 years (median G SD), and the median gestational age at delivery was 35.5 G 4.9 weeks. The most frequent signs and symptoms of hepatic rupture were the sudden onset of abdominal pain, acute anemia, and hypotension. Laboratory findings included low platelet count and increased hepatic enzymes. Surgery was performed in 9 cases. One case was treated nonsurgically. The maternal mortality rate was 10%, and the perinatal mortality rate was 80%. Conclusion: A combination of surgical treatment with hepatic artery ligation and omental patching with supportive measures was effective in decreasing the mortality rate in hepatic rupture caused by HELLP syndrome.
etc... 3-MATERIAIS E MÉTODOS: quando se trata de pesquisas documentais, bibliográficas ou históri... more etc... 3-MATERIAIS E MÉTODOS: quando se trata de pesquisas documentais, bibliográficas ou históricas utiliza-se a TERMINOLOGIA: METODOLOGIA. Porém em pesquisas de campo, usar a TERMINOLOGIA MATERIAIS E MÉTODOS.
An approach to guide a mobile robot from an initial position to a goal position avoiding any obst... more An approach to guide a mobile robot from an initial position to a goal position avoiding any obstacle in its path, when navigating in a semi-structured environment, is proposed in this paper. Such an approach, hereinafter referred to as tangential escape, consists in changing the current robot orientation through a suitable combination of the values of the angular and linear velocities (the control actions) whenever an obstacle is detected close to it. Then, the robot starts navigating in parallel to the tangent to the obstacle, regarding the point of the obstacle boundary the robot sensing system identifies as the closest one. The stability of the control system designed according this approach is proven, showing that the robot reaches any reachable goal, with or without a prescribed final orientation. Such a control system is programmed onboard a mobile platform whose sensing system is a laser scanner which provides 181 range measurements, for experimental validation. The results obtained are presented and discussed, allowing concluding that the tangential escape approach is able to guide the robot along trajectories that result in a reduction of the traveling time, thus saving batteries and reducing the motor wearing.
Estudos recentes (CHIVIACOWSKY & WULF, 2007) têm mostrado que a aprendizagem é realmente benefici... more Estudos recentes (CHIVIACOWSKY & WULF, 2007) têm mostrado que a aprendizagem é realmente beneficiada em adultos se, aos aprendizes, for fornecido "feedback" após "boas" tentativas em vez de após "más" tentativas. O presente estudo procurou examinar se o mesmo efeito pode ser observado em crianças. Foram utilizadas 40 crianças como sujeitos. Os participantes praticaram uma tarefa de arremessar saquinhos de feijão em um alvo, com a mão não-dominante, sem enxergar o alvo durante os arremessos. Todos os participantes receberam 50% de freqüência de conhecimento de resultados (CR), ou seja, em três tentativas em cada bloco de seis tentativas. Enquanto a um grupo foram fornecidos CRs para as três tentativas mais efetivas de cada bloco, a outro grupo foram fornecidos CRs para as três tentativas menos efetivas de cada bloco. A análise dos dados foi realizada através da ANOVA, utilizando-se o pacote estatístico SPSS. Discordando dos resultados encontrados em adultos, não foram verificadas diferenças significativas entre os grupos na fase de retenção.
Acta Obstetricia Et Gynecologica Scandinavica, 2010
Objective. To determine the risk of preeclampsia in a population with respect to maternal and sis... more Objective. To determine the risk of preeclampsia in a population with respect to maternal and sister histories of chronic hypertension, preeclampsia and eclampsia. Design. A case-control study of severe preeclampsia. Setting. Maternity hospital in Natal, Brazil. Participants. A total of 412 subjects were enrolled, 148 cases and 264 controls. Main outcome measures. Personal and familial histories of hypertensive disorders. Odds ratio estimates of preeclampsia with respect to family history of hypertensive diseases. Results. Women with a history of hypertensive disorders were more frequent in the case group (p = 0.001). Women whose mothers had a history of hypertension (p = 0.003), preeclampsia (p = 0.007) or eclampsia (p = 0.038) were at increased risk of severe preeclampsia. The risk of preeclampsia was greater when the woman had a sister with a history of hypertension (OR 2.60, 95% CI 1.60-4.21, p < 0.001), preeclampsia (OR 2.33, 95% CI 1.58-3.45, p < 0.001), or eclampsia (OR 2.57, 95% CI 1.28-5.16, p = 0.008). The risk of preeclampsia was also higher for women who had both a mother and sister with a history of hypertension (OR 3.65, 95% CI 1.65-8.09, p = 0.001). Conclusions. A family history of hypertensive disorders increased the risk of eclampsia and hemolysis elevated liver enzymes and low platelet (HELLP) syndrome in a Brazilian population.
American Journal of Obstetrics and Gynecology, 2006
Hepatic rupture HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome Preecl... more Hepatic rupture HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome Preeclampsia Hepatic artery ligation Objective: The purpose of this study was to review the management of hepatic rupture caused by HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome and to assess maternal and perinatal outcomes of these cases. Study design: A retrospective study of HELLP syndrome cases that were complicated by hepatic rupture was conducted. Results: Ten cases of hepatic rupture were identified. The median maternal age was 42.5 G 5.9 years (median G SD), and the median gestational age at delivery was 35.5 G 4.9 weeks. The most frequent signs and symptoms of hepatic rupture were the sudden onset of abdominal pain, acute anemia, and hypotension. Laboratory findings included low platelet count and increased hepatic enzymes. Surgery was performed in 9 cases. One case was treated nonsurgically. The maternal mortality rate was 10%, and the perinatal mortality rate was 80%. Conclusion: A combination of surgical treatment with hepatic artery ligation and omental patching with supportive measures was effective in decreasing the mortality rate in hepatic rupture caused by HELLP syndrome.
etc... 3-MATERIAIS E MÉTODOS: quando se trata de pesquisas documentais, bibliográficas ou históri... more etc... 3-MATERIAIS E MÉTODOS: quando se trata de pesquisas documentais, bibliográficas ou históricas utiliza-se a TERMINOLOGIA: METODOLOGIA. Porém em pesquisas de campo, usar a TERMINOLOGIA MATERIAIS E MÉTODOS.
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