Development of a virtual reality laboratory stressor

Virtual Reality - This research report describes the development of a virtual reality (VR) laboratory stressor to study the effects of exposure to stressful events. The aim of the research was to...     

Experimental and numerical study of the recirculation flow inside a liquid meniscus focused by air

The internal motions inside a liquid meniscus in the so-called liquid cone-jet mode, which can occur upon stimulation by a coflowing gas sheath in flow focusing, are explored by both numerical simulation and experimental visualization. The results for low viscosity liquids show that, as in previous numerical simulations, a recirculating cell inside the meniscus appears when the injected liquid flow rate is reduced. Thus, as the flow rate is reduced not only the average residence time of particles in the meniscus becomes longer, but the appearance of a recirculation cell provides a natural platform for the efficient micro-mixing of different species before they are ejected through the issuing jet. The numerical results were confirmed with experimental visualization of the flow inside the meniscus using a dyed liquid. However, when the viscosity of the liquid is increased the recirculating cell disappears. In this case, viscous stresses organize the streamlines and direct the flow to the meniscus tip, which prevents the recirculating cell from being formed even for very small injected rate of liquid flow.     

Risk Factors for Partner Violence Among a National Sample of Combat Veterans.

In this study, the authors identified potential risk factors for partner violence perpetration among a subsample (n=109) of men who participated in a national study of Vietnam veterans. Partner violent (PV) men with posttraumatic stress disorder (PTSD) were compared with PV men without PTSD and nonviolent men with PTSD on family-of-origin variables, psychiatric problems, relationship problems, and war-zone factors. PV men with PTSD were the highest of the 3 groups on every risk factor other than childhood abuse. Group contrasts and a classification tree analysis suggest some potential markers and mechanisms for the association between PTSD and partner violence among military veterans and highlight the need for theory development in this area of inquiry. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Forensic surface metrology: tool mark evidence

Over the last several decades, forensic examiners of impression evidence have come under scrutiny in the courtroom due to analysis methods that rely heavily on subjective morphological comparisons. Currently, there is no universally accepted system that generates numerical data to independently corroborate visual comparisons. Our research attempts to develop such a system for tool mark evidence, proposing a methodology that objectively evaluates the association of striated tool marks with the tools that generated them. In our study, 58 primer shear marks on 9?mm cartridge cases, fired from four Glock model 19 pistols, were collected using high-resolution white light confocal microscopy. The resulting three-dimensional surface topographies were filtered to extract all "waviness surfaces"-the essential "line" information that firearm and tool mark examiners view under a microscope. Extracted waviness profiles were processed with principal component analysis (PCA) for dimension reduction. Support vector machines (SVM) were used to make the profile-gun associations, and conformal prediction theory (CPT) for establishing confidence levels. At the 95% confidence level, CPT coupled with PCA-SVM yielded an empirical error rate of 3.5%. Complementary, bootstrap-based computations for estimated error rates were 0%, indicating that the error rate for the algorithmic procedure is likely to remain low on larger data sets. Finally, suggestions are made for practical courtroom application of CPT for assigning levels of confidence to SVM identifications of tool marks recorded with confocal microscopy.     

CD8+ T Cell Senescence: Lights and Shadows in Viral Infections,Autoimmune Disorders and Cancer

CD8⁺ T lymphocytes are a heterogeneous class of cells that play a crucial role in the adaptive immune response against pathogens and cancer. During their lifetime, they acquire cytotoxic functions to ensure the clearance of infected or transformed cells and, in addition, they turn into memory lymphocytes, thus providing a long-term protection. During ageing, the thymic involution causes a reduction of circulating T cells and an enrichment of memory cells, partially explaining the lowering of the response towards novel antigens with implications in vaccine efficacy. Moreover, the persistent stimulation by several antigens throughout life favors the switching of CD8⁺ T cells towards a senescent phenotype contributing to a low-grade inflammation that is a major component of several ageing-related diseases. In genetically predisposed young people, an immunological stress caused by viral infections (e.g., HIV, CMV, SARS-CoV-2), autoimmune disorders or tumor microenvironment (TME) could mimic the ageing status with the consequent acceleration of T cell senescence. This, in turn, exacerbates the inflamed conditions with dramatic effects on the clinical progression of the disease. A better characterization of the phenotype as well as the functions of senescent CD8⁺ T cells can be pivotal to prevent age-related diseases, to improve vaccine strategies and, possibly, immunotherapies in autoimmune diseases and cancer.     

电信重组今秋揭晓,盲目投资易栽跟头

日前,在买卖中国电信业巨头股票时,遵循"在传言时买进,在证实时卖出"这一"古训"的投资者们遭受了严重损失.     

"A conception of adult development": Reply.

D. J. Levinson's (see record 1986-19674-001) conceptualization of adult development presents a rich avenue for exploring personal growth and the effects of life-cycle changes both in and out of therapy. Research in this area can elucidate such issues as sociocultural changes in the timing of major life-cycle events (e.g., childbearing, retirement) and life-crisis stressors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Options and overbooking strategy in the management of wireless spectrum

Dynamic spectrum management makes it possible for the owner of usage rights on some frequency blocks to sublet each of them in real time and for a limited period of time. As a softer implementation with respect to the spot market a two stage assignment is here proposed through the use of options, which give buyers the right to purchase the usage right on a single block and for a timeslot. In the sale of options the primary owner may accomplish an overbooking strategy, which consists in selling more blocks than the available ones, and acts as a hedging tool against the risk of unsold blocks. A model for the overbooking strategy is described and evaluated, which takes into account both the value of the option, the correlated decisions taken by the prospective purchasers, and the penalty to be paid to the unsatisfied customers. The dependence of the economical convenience of the overbooking strategy on the relevant parameters (among which the penalty value and the overbooking ratio) is shown for a significant range of cases.     

Neuronal responses in visual areas MT and MST during smooth pursuit target selection

We recorded the activity of single neurons in the middle temporal (MT) and middle superior temporal (MST) visual areas in two macaque monkeys while the animals performed a smooth pursuit target selection task. The monkeys were presented with two moving stimuli of different colors and were trained to initiate smooth pursuit to the stimulus that matched the color of a previously given cue. We designed these experiments so that we could separate the component of the neuronal response that was driven by the visual stimulus from an extraretinal component that predicted the color or direction of the selected target. We found that for all cells in MT and MST the response was primarily determined by the visual stimulus. However, 14% (8 of 58) of MT neurons and 26% (22 of 84) of MST neurons had a small predictive component that was significant at the P < or = 0.05 level. In some cells, the predictive component was clearly related to the color of the intended target, but more often it was correlated with the direction of the target. We have previously documented a systematic shift in the latency of smooth pursuit that depends on the relative direction of motion of the two stimuli. We found that neither the latency nor the amplitude of neuronal responses in MT or MST was correlated with behavioral latency. These results are consistent with a model for target selection in which a weak selection bias for the intended target is amplified by a competitive network that suppresses motion signals related to the nonintended stimulus. It is possible that the predictive component of neuronal responses in MT and MST contributes to the selection bias. However, the strength of the selection bias in MT and MST is not sufficient to account for the high degree of selectivity shown by pursuit behavior.