Stimulated release of tissue plasminogen activator from artery wall sympathetic nerves: implications for stress-associated wall damage

Recurrent stress is clinically associated with early onset hypertension and coronary artery disease. A mechanism linking emotion to pathogenic remodeling of the artery wall has not been identified. Stress stimulates acute regulated release of tissue plasminogen activator (t-PA) into the circulation, which is presently attributed to the vascular endothelium. Sympathetic neurons also synthesize t-PA and axonally transport it to the arterial smooth muscle. Unlike release by the endothelium, a stress-stimulated sympathetic discharge would potentially accelerate degradation of the wall matrix by plasmin. To assess whether sympathetic axons are the principal source of acute stress-induced arterial release of t-PA, we compared the output from small densely innervated and large sparsely innervated isolated artery segments before and after sympathetic stimulation, and after ablations. Following phenylephrine infusion densely-innervated microvessels in uveal eyecups were released over 60-fold greater amounts of active t-PA per milligram than the sparsely innervated aorta; and ten-fold more than carotid artery segments. Mesenteric artery release was 4.8-fold greater than release by the carotid artery. In vivo, uveal release of t-PA increased more than three-fold within one minute following superior cervical sympathetic ganglion electrical stimulation, and after phenylephrine, or nicotine infusions of the anterior chamber. Circulating levels of t-PA fell 70% following chemical sympathectomy. We propose that sympathetic nerves are the primary source of stress-induced release of t-PA into and from the densely innervated resistance arteries and arterioles, where dysregulated plasmin-induced proteolysis could damage the wall matrix.     

Trace fear conditioning is reduced in the aging rat

Auditory trace fear conditioning is a hippocampus-dependent learning task that requires animals to associate an auditory conditioned stimulus (CS) and a fear-producing shock-unconditioned stimulus (US) that are separated by an empty 20-s trace interval. Previous studies have shown that aging impairs learning performance on hippocampus-dependent tasks. This study measured heart rate (HR) and freezing fear responses to determine if aging impairs hippocampus-dependent auditory trace fear conditioning in freely moving rats. Aging and Young rats received one long-trace fear conditioning session (10 trials). Each trial consisted of a tone-CS (5 s) and a shock-US separated by an empty 20-s trace interval. The next day rats received CS-alone retention trials. Young rats showed significantly larger HR and freezing responses on the initial CS-alone retention trials compared to the Aging rats. A control group of aging rats received fear conditioning trials with a short 1-s trace interval separating the CS and US. The Aging Short-Trace Group showed HR and freezing responses on the initial CS alone retention trials that were similar to the Young Long-Trace Group, but greater than the Aging Long-Trace Group. A second aging control group received unpaired CSs and USs, and showed no HR or freezing responses on CS-alone retention trials. These data show that HR and freezing are effective measures for detecting aging-related deficits in trace fear conditioning.     

Improving measurement precision of test batteries using multidimensional item response models

A conventional way to analyze item responses in multiple tests is to apply unidimensional item response models separately, one test at a time. This unidimensional approach, which ignores the correlations between latent traits, yields imprecise measures when tests are short. To resolve this problem, one can use multidimensional item response models that use correlations between latent traits to improve measurement precision of individual latent traits. The improvements are demonstrated using 2 empirical examples. It appears that the multidimensional approach improves measurement precision substantially, especially when tests are short and the number of tests is large. To achieve the same measurement precision, the multidimensional approach needs less than half of the comparable items required for the unidimensional approach.     

Factorial structure of the kidcope in Hong Kong adolescents

The Kidcope (A. Spirito, L. J. Stark, & C. Williams, 1988), a brief screening measure of coping strategies for children and adolescents, was subjected to exploratory and confirmatory factor analyses in a sample of adolescents in Hong Kong. A 2-factor model was found to fit the data when only the 2 emotional regulation items were treated separately and were allowed to load on the 2 different factors. Further analyses showed that factor loadings, factor variances, and factor covariance were invariant across age and gender. On the basis of the factor analyses, the authors created 2 composite scores, representing control-oriented and escape-oriented coping strategies. Implications for the use of the Kidcope in research and preventive intervention are discussed.     

Pastoral counseling among Chinese churches: a Canadian study

This article reports the results of a survey of Canadian Chinese pastors (N 20) regarding their experiences and attitudes related to pastoral counseling. It identifies common concerns encountered during pastoral counseling, as well as key areas of church concerns. Results of the survey indicate that pastoral counseling may be more important than is currently recognized by Chinese pastors, particularly in key areas of marriage, family life, and general relationship issues. The authors discuss possible implications of the survey relative to training and equipping Chinese pastors to engage more in pastoral counseling as an integral part of their parish ministry.     

掩蔽刺激的空间参考框架对视觉表象旋转的影响

本实验通过将具有参考框架信息的前置刺激改为掩蔽刺激,进一步探讨参考框架的变化和表象旋转的过程。结果表明：１、因掩蔽刺激而引起的主观参考框架的产生是瞬间完成的,而不是由原先直立的参考框架经过连续旋转后形成的。２、显示了倾斜字母的加工不完全是整体表象的线性旋转过程,而可能是整字一成分的混合加工过程。     

学前数学教法和儿童智能发展的追踪研究

本研究从儿童心理发展的特点和数学学习之间的内在规律出发,综合考查了各类教学法在学前施教的利弊;同时,在活动教法、指导操作法、演示法和讲授法之间做了对比实验,并设计了一整套以指导操作法为主的学前数学教法,以演示为主的数学教法之间进行了长期、深人的跟踪对比实验。结果表明,在其他变量基本被控制的条件下,指导操作法优于其他的教法;实验班儿童的智能发展,特别是数学能力的发展,明显好于对照班的儿童。这个优势一直持续到小学毕业。     

Bootstrap assessment of the reliability of maxima in surface maps of brain activity of individual subjects derived with electrophysiological and optical methods

Surface maps of brain activity can be obtained with electrophysiological and optical recordings. However, there are no established methods for determining the reliability of maps of brain activity across subject groups or across tasks within the same subject. In this paper, we use bootstrapping to establish the reliability of the locations of maxima in maps of surface brain activity of individual subjects obtained with ERP and optical (EROS) recordings and report sample analyses for two data sets. Bootstrapping is a nonparametric method for estimating statistical accuracy from the data in a single sample. The distribution of the statistic of interest is estimated by constructing “bootstrap samples” from a pool of all available cases (with replacement). Many “bootstrap replications” are obtained by calculating the statistic of interest for each sample. In the case of brain activity, many (e.g., 10,000) amplitude distributions can be derived from the data of an individual subject. Frequency counts are then computed for each recording location to establish how many times that location corresponds to a maximum. The value obtained in this fashion represents an estimate of the reliability of the observation.     

刺激属性对内隐社会知觉的影响

本文通过选择不同词性（消极词、积极词和中性词）的双字词64个,主要对“刺激属性”变量进行了实验操作;采用“意识过滤”技术和速示辨认测验对内隐社会知觉的特点进行了考察;结果发现,实验材料的笔划数和被试的性别对内隐社会知觉没有影响,刺激的特性和刺激的启动作用对内除社会知觉有显著的影响;同时还证明速示辨认测验不受意识的“污染”,将速示辨认作为内臆测验的方法是比较“纯净的”。     

Looking more masculine among females: Spatial context modulates gender perception of face and biological motion

Perception of visual information highly depends on spatial context. For instance, perception of a low-level visual feature, such as orientation, can be shifted away from its surrounding context, exhibiting a simultaneous contrast effect. Although previous studies have demonstrated the adaptation aftereffect of gender, a high-level visual feature, it remains largely unknown whether gender perception can also be shaped by a simultaneously presented context. In the present study, we found that the gender perception of a central face or a point-light walker was repelled away from the gender of its surrounding faces or walkers. A norm-based opponent model of lateral inhibition, which accounts for the adaptation aftereffect of high-level features, can also excellently fit the simultaneous contrast effect. But different from the reported contextual effect of low-level features, the simultaneous contrast effect of gender cannot be observed when the centre and the surrounding stimuli are from different categories, or when the surrounding stimuli are suppressed from awareness. These findings on one hand reveal a resemblance between the simultaneous contrast effect and the adaptation aftereffect of high-level features, on the other hand highlight different biological mechanisms underlying the contextual effects of low- and high-level visual features.