Spacecraft attitude detection system by stellar reference Patent

Attitude detection system using stellar references for three-axis control and spin stabilized spacecraf

Distances on probability measures and random variables

AbstractIn this paper we lift fundamental topological structures on probability measures and random variables, in particular the weak topology, convergence in law and finite-dimensional convergence to an isometric level. This allows for an isometric quantitative study of important concepts such as relative compactness, tightness, stochastic equicontinuity, Prohorov's theorem and σ-smoothness. In doing so we obtain numerical results which allow for the development of an intrinsic approximation theory and from which moreover all classical topological results follow as easy corollaries

Influenza Virus Infection in Guinea Pigs Raised as Livestock, Ecuador

To determine whether guinea pigs are infected with influenza virus in nature, we conducted a serologic study in domestic guinea pigs in Ecuador. Detection of antibodies against influenza A and B raises the question about the role of guinea pigs in the ecology and epidemiology of influenza virus in the region

Emotional Reaction Facilitates the Brain and Behavioral Impact of Graphic Cigarette Warning Labels in Smokers

Background—Warning labels on cigarette packages are an important venue for information about the hazards of smoking. The 2009 US Family Smoking Prevention and Tobacco Control Act mandated replacing the current text-only labels with graphic warning labels. However, labels proposed by the Food and Drug Administration (FDA) were challenged in court by the tobacco companies, who argued successfully that the proposed labels needlessly encroached on their right to free speech, in part because they included images of high emotional salience that indiscriminately frightened rather than informed consumers. Methods—We used functional MRI to examine the effects of graphic warning labels\u27 emotional salience on smokers\u27 brain activity and cognition. Twenty-four smokers viewed a random sequence of blocks of graphic warning labels that have been rated high or low on an ‘emotional reaction’ scale in previous research. Results—We found that labels rated high on emotional reaction were better remembered, associated with reduction in the urge to smoke, and produced greater brain response in the amygdala, hippocampi, inferior frontal gyri and the insulae. Conclusions—Recognition memory and craving are, respectively, correlates of effectiveness of addiction related public health communications and interventions, and amygdala activation facilitates the encoding of emotional memories. Thus, our results suggest that emotional reaction to graphic warning labels contributes to their public health impact and may be an integral part of the neural mechanisms underlying their effectiveness. Given the urgency of the debate about the constitutional risks and public health benefits of graphic warning labels, these preliminary findings warrant consideration while longitudinal clinical studies are underwa

Non-equilibrium dynamics of stochastic point processes with refractoriness

Stochastic point processes with refractoriness appear frequently in the quantitative analysis of physical and biological systems, such as the generation of action potentials by nerve cells, the release and reuptake of vesicles at a synapse, and the counting of particles by detector devices. Here we present an extension of renewal theory to describe ensembles of point processes with time varying input. This is made possible by a representation in terms of occupation numbers of two states: Active and refractory. The dynamics of these occupation numbers follows a distributed delay differential equation. In particular, our theory enables us to uncover the effect of refractoriness on the time-dependent rate of an ensemble of encoding point processes in response to modulation of the input. We present exact solutions that demonstrate generic features, such as stochastic transients and oscillations in the step response as well as resonances, phase jumps and frequency doubling in the transfer of periodic signals. We show that a large class of renewal processes can indeed be regarded as special cases of the model we analyze. Hence our approach represents a widely applicable framework to define and analyze non-stationary renewal processes.Comment: 8 pages, 4 figure