Civil tiltrotor missions and applications. Phase 2: The commercial passenger market

The commercial passenger market for the civil tiltrotor was examined in phase 2. A market responsive commercial tiltrotor was found to be technically feasible, and a significant worldwide market potential was found to exist for such an aircraft, especially for relieving congestion in urban area-to-urban area service and for providing cost effective hub airport feeder service. Potential technical obstacles of community noise, vertiport area navigation, surveillance, and control, and the pilot/aircraft interface were determined to be surmountable. Nontechnical obstacles relating to national commitment and leadership and development of ground and air infrastructure were determined to be more difficult to resolve; an innovative public/private partnership is suggested to allow coordinated development of an initial commercial tiltrotor network to relieve congestion in the crowded US Northeast corridor by the year 2000

Bonsai Trees in Your Head: How the Pavlovian System Sculpts Goal-Directed Choices by Pruning Decision Trees

When planning a series of actions, it is usually infeasible to consider all potential future sequences; instead, one must prune the decision tree. Provably optimal pruning is, however, still computationally ruinous and the specific approximations humans employ remain unknown. We designed a new sequential reinforcement-based task and showed that human subjects adopted a simple pruning strategy: during mental evaluation of a sequence of choices, they curtailed any further evaluation of a sequence as soon as they encountered a large loss. This pruning strategy was Pavlovian: it was reflexively evoked by large losses and persisted even when overwhelmingly counterproductive. It was also evident above and beyond loss aversion. We found that the tendency towards Pavlovian pruning was selectively predicted by the degree to which subjects exhibited sub-clinical mood disturbance, in accordance with theories that ascribe Pavlovian behavioural inhibition, via serotonin, a role in mood disorders. We conclude that Pavlovian behavioural inhibition shapes highly flexible, goal-directed choices in a manner that may be important for theories of decision-making in mood disorders

An N-methyl-d-aspartate receptor agonist facilitates sleep-independent synaptic plasticity associated with working memory capacity enhancement

Working memory (WM) capacity improvement is impacted by sleep, and possibly by N-methyl-D-aspartate (NMDA) agonists such as D-cycloserine (DCS), which also affects procedural skill performance. However, the mechanisms behind these relationships are not well understood. In order to investigate the neural basis underlying relationships between WM skill learning and sleep, DCS, and both sleep and DCS together, we evaluated training-retest performances in the n-back task among healthy subjects who were given either a placebo or DCS before the task training, and then followed task training sessions either with wakefulness or sleep. DCS facilitated WM capacity enhancement only occurring after a period of wakefulness, rather than sleep, indicating that WM capacity enhancement is affected by a cellular heterogeneity in synaptic plasticity between time spent awake and time spent asleep. These findings may contribute to development, anti-aging processes, and rehabilitation of higher cognition

Neural correlates of anger expression in patients with PTSD

Anger is a common and debilitating symptom of post-traumatic stress disorder (PTSD). Although studies have identified brain circuits underlying anger experience and expression in healthy individuals, how these circuits interact with trauma remains unclear. Here, we performed the first study examining the neural correlates of anger in patients with PTSD. Using a data-driven approach with resting-state fMRI, we identified two prefrontal regions whose overall functional connectivity was inversely associated with anger: the left anterior middle frontal gyrus (aMFG) and the right orbitofrontal cortex (OFC). We then used concurrent TMS-EEG to target the left aMFG parcel previously identified through fMRI, measuring its cortical excitability and causal connectivity to downstream areas. We found that low-anger PTSD patients exhibited enhanced excitability in the left aMFG and enhanced causal connectivity between this region and visual areas. Together, our results suggest that left aMFG activity may confer protection against the development of anger, and therefore may be an intriguing target for circuit-based interventions for anger in PTSD

Comparação entre métodos de estimação do coeficiente de endogamia com dados de frequências alélicas em uma população diplóide Comparison among inbreeding coefficient estimation methods in a diploid population with two alleles

Neste trabalho, objetivou-se comparar três estimadores do coeficiente de endogamia, F, em uma população diplóide com dois alelos, utilizando-se dados de frequências alélicas em amostras de indíviduos, com diferentes tamanhos obtidas em populações simuladas, por meio do software SAS. Foi avaliado o estimador de F, obtido pela análise de variância de frequências alélicas, o estimador considerando o método dos momentos e o estimador pelo método da máxima verossimilhança. Os resultados encontrados para a média e variância os estimadores, a partir de 1000 estimativas de F, calculadas para cada tamanho de amostra, mostraram que os três estimadores são tendenciosos. Entretanto, de maneira geral, observou-se que o estimador considerando a análise de variância foi menos tendencioso e apresentou menor variância, quando o coeficiente de endogamia da população foi alto. Para tamanho de amostra superior a 50, os três estimadores tiveram comportamento semelhante, independente da frequência alélica e da endogamia da população.<br>The present work evaluated the properties of three estimators of the inbreeding coefficient, F, in a diploid population with two alleles, using data of gene frequencies in individuals from random samples obtained from populations simulated through the SAS. We evaluated the estimators of F obtained by variance analysis of allelic frequencies, obtained by moment method, and estimator obtained by maximum likelihood method. The analysis of the means and variances of the estimators, obtained from 1000 estimates of F, calculated for each sample size, demonstrated that the three estimators were biased. However, it was observed that the estimator obtained from univariate analysis was less biased and presented smaller variance, when the inbreeding coefficient in the population was elevated, while for populations with low inbreeding, the variance of the estimator obtained by the multivariate analysis was smaller

Mortalidade materna no estado da Paraíba: associação entre variáveis Mortalidad materna en el estado de Paraíba-Brasil: asociación entre variables Maternal mortality in the state of Paraíba-Brazil: association between variables

A mortalidade materna tem se constituído em um dos problemas prioritários de saúde pública, afetando diretamente as mulheres no ciclo grávido puerperal pertencentes às classes sociais menos favorecidas. Diante desta situação o objetivo deste estudo consistiu em identificar associações entre a raça de mulheres residentes no estado da Paraíba, e as variáveis grupo etário, escolaridade e tipo de óbito das mulheres que foram a óbito por morte materna no período de 2000 a 2004. Trata-se de um estudo transversal, cuja fonte de dados constituiu-se de 109 declarações de óbitos maternos. Procedeu-se a uma análise estatística bivariada e multivariada, para avaliar a associação existente entre as variáveis através da regressão logística múltipla. Calculou-se o odds ratio para investigar a associação entre as variáveis. Observou-se que não houve significância estatística entre as variáveis raça e idade, bem como por escolaridade, mas houve indícios significativos de que as mulheres não brancas da Paraíba tiveram mais chance de morrer por morte obstétrica direta (OR=3,55; IC:1,20-10,5). Os resultados mostraram que o risco de mortalidade materna na Paraíba foi maior entre as mulheres não brancas, configurando-se em importante expressão de desigualdade social.<br>La mortalidad materna se ha constituido en uno de los problemas prioritarios de la salud pública, afectando directamente a mujeres en el ciclo grávido-puerperal, pertenecientes a las clases sociales menos favorecidas. Ante esta situación, el objetivo de este estudio consistió en identificar asociaciones entre la raza de mujeres residentes en el estado de Paraíba - Brasil y las variables de grupo etario, escolaridad, y tipo de defunción de las mujeres que fallecieron por muerte materna en el período de 2000 a 2004. Se trata de un estudio transversal, en el que se utilizaron como fuente de datos 109 partidas de defunción maternas. Se procedió a un análisis estadístico bivariado y multivariado para evaluar la asociación existente entre las variables a través de la regresión logística múltiple. Se calculó el odds ratio para investigar la asociación entre las variables. Se observó que no hubo significatividad estadística entre las variables raza y edad, así como con escolaridad, pero existieron indicios significativos de que las mujeres no blancas de Paraíba tuvieron mayores posibilidades de fallecer por muerte obstétrica directa (OR=3,55, IC: 1,20-10,5). Los resultados demostraron que el riesgo de mortalidad materna en Paraíba fue mayor entre las mujeres no blancas, dando forma así a una importante expresión de desigualdad social.<br>Maternal mortality has been established as one of the priority problems of public health, directly affecting women in the pregnant puerperal cycle and belonging to underprivileged social classes. Considering this situation, the aim of the present study was to identify associations between the race of women living in the state of Paraíba and age, educational level and type of death of women who died of maternal death in the period 2000 to 2004. This cross-sectional study used as a source of data declarations of 109 maternal deaths. Bivariate and multivariate statistical analyses were performed to evaluate the association between variables using multiple logistic regression. The odds ratio to investigate the association between variables was calculated. It was observed that there was no statistical significance between race and age variables or with educational level, but there was significant evidence that non-white women from Paraíba were more likely to die from direct obstetric death than white women , (OR = 3.55; IC: 1,20-10,5). The results showed that the risk of maternal mortality in Paraíba was higher among non-white women, revealing an important expression of social inequality