Heart rate--QT relationships during baroreceptor stimulation with diminished autonomic influence on the ventricles. Ventricular autonomic tone and QT interval.

The shortening of the QT interval of the electrocardiogram coincident with acceleration of heart rate and vice versa has been accepted for many years as evidence that the action potential duration and hence QT are necessarily dependent on heart rate. Exceptions to this rule have been attributed to the intervention of counteracting autonomic effects. In order to test this assumption, 26 conscious dogs divided into three groups were tested during baroreceptor stimulation by a bolus injection of phenylephrine. Seventeen dogs had been used in earlier studies in which they had undergone an experimental anterior myocardial infarction with apparent full recovery. A group of those dogs underwent beta-adrenergic blockade by intravenous atenolol 30 min prior to the baroreceptor activation. To test the intactness of the baroreceptor responses in the previously infarcted dogs, a third group of nine dogs that had had no prior myocardial infarction was included. All dogs were adapted to the laboratory environment and were not sedated during experiments. Simultaneous recordings of RR, QT interval, and phasic arterial pressure were made in all dogs before and during baroreceptor stimulation. In the normal group, and the previously infarcted group that received no atenolol, baroreceptor stimulation elicited a small (8/msec), but significant prolongation of the QT associated with a nearly 50% reduction in heart rate. The QT interval of the atenolol-treated dogs, although significantly more prolonged before stimulation, remained unchanged during the reflex. The data indicate that withdrawal of ventricular sympathetic tone may prolong the QT interval, thereby confirming the role of sympathetic innervation in the control of QT.(ABSTRACT TRUNCATED AT 250 WORDS)     

SEEING TWO AS ONE:

Abstract -Object tokens are episodic visual representations that mediate the ability to track visual events as they move about and change over time. Multiple tokens also allow the viewer to individuate multiple instances of a single type of object. In the present study, we established a functional link for object tokens in two seemingly disparate visual phenomena: apparent motion and repetition blindness [RB]. In RB, repeated items are more difficult to perceive than unre-peated items. Using displays in which two sets of alphanumeric characters streamed in opposite directions across a computer screen in apparent motion, we found increased RB for targets appearing within a single apparent motion stream, relative to targets in different apparent motion streams. The results are inconsistent with refractory period or memory retrieval accounts of RB and support the role of object tokens in both apparent motion and RB.     

Transfer of reaction inhibition

A serious challenge to Hull's (1943) theory of reminiscence and intertrial-interval effects is posed by the current contention that reactive inhibition (In) must be task-specific since it does not seem to transfer from one task to another. This notion was examined within the framework of a practice-rest paradigm in which three control groups were given 20 1-min trials on a principal task with intertrial intervals of 0, 5, and 70 sec, respectively, while two experimental groups practiced alternately on the principal task and a secondary task known to produce evidence for I(R). The two secondary tasks varied in their similarities to the principal task. Additional control groups were used to assess the magnitude of habit transfer effects. The total sample consisted of 70 males and 70 females whose modal age was 18 yr. With habit transfer effects controlled, results showed clearly that work effects transferred from the alternate tasks to the main task without regard for differences in similarity. Thus, the task-specificity hypothesis was not supported.     

Age-related enhancement of a protein synthesis-dependent late phase of LTP induced by low frequency paired-pulse stimulation in hippocampus

Protein synthesis-dependent late phase of LTP (L-LTP) is typically induced by repeated high-frequency stimulation (HFS). This form of L-LTP is reduced in the aged animal and is positively correlated with age-related memory loss. Here we report a novel form of protein synthesis-dependent late phase of LTP in the CA1 region of hippocampus induced by a brief 1-Hz paired-pulse stimulation (PP-1 Hz, 1 min). In contrast to L-LTP induced by HFS, the late phase of PP-1 Hz LTP does not exist in young adult animals. Rather, it emerges and becomes enhanced in an age-related way. Thus, in 1.5- to 2-mo-old mice, a brief PP-1 Hz stimulation induces only a short lasting LTP, decaying to baseline in about 90 min. By contrast, PP-1 Hz stimulation induces an enduring and protein synthesis dependent LTP in 12- to 18-mo-old mice. The PP-1 Hz-induced L-LTP is dependent on NMDA receptor activation, requires voltage-dependent calcium channels, and is modulated by dopamine D1/D5 receptors. Because memory ability declines with aging, the age-related enhancement of L-LTP induced by PP-1 Hz stimulation indicates that this form of L-LTP appears to be inversely correlated with memory ability.     

Effects of wrist rest and forearm support on muscle activity

This study examined the effects of wrist rest and forearm support on reducing computer operators' activities using the trapezius, deltoid, biceps brachii, extensor carpi radialis longus, and extensor digitorum. 12 young (M= 25.9 yr., SD= 2.4) men were asked to perform both static and dynamic mouse operations in four conditions, two using a wrist rest and two using a forearm support. Analysis showed that use of the forearm support had a significant effect on reducing the EMG activity in muscles of the trapezius, deltoid, biceps brachii, extensor carpi radialis longus, and extensor digitorum. However, the wrist rest only significantly reduced deltoid and extensor carpi radialis longus activities.     

A typology of religious attitudes among young people in Germany

Issues like faith and Church, religion and religiousness are not valued particularly highly among the young. At the same time a search for the meaning of life and an orientation in one’s own behaviour still seem to be significant and transcendent focal points are being sought to deal with these issues. This article questions the value that religion, faith and the Church have for young people on the basis of empirical data. Five types of religious orientation of young people are identified: a churchly Christian type, an autonomously Christian type, a conventionally religious type, an autonomously religious type and, finally, a non‐religious type. The empirical data are taken from a study of about 800 pupils in the Grade 11 (age 16–17 years) from grammar schools (Gymnasien) in Germany.     

The Unhappy Marriage of Care Ethics and Virtue Ethics

The proposal that care ethic(s) (CE) be subsumed under the framework of virtue ethic(s) (VE) is both promising and problematic for feminists. Although some attempts to construe care as a virtue are more commendable than others, they cannot duplicate a freestanding feminist CE. Sander‐Staudt recommends a model of theoretical collaboration between VE and CE that retains their comprehensiveness, allows CE to enhance VE as well as be enhanced by it, and leaves CE open to other collaborations.     

词频和年级对FOK判断的影响

本实验以识记材料的词频高低和被试年级为自变量对被试元记忆监测的FOK(feeling of knowing)判断进行研究。实验采用Hart提出的RJR(回忆—FOK判断—标准测验 )的经典范式。结果表明 :被试的年级影响FOK判断等级和准确性 ,大学生的FOK判断等级和准确性均高于高一年级学生 ;识记材料词频影响FOK判断等级的高低 ,不影响FOK判断准确性 ,被试对高频词对的FOK判断等级高于对低频词对的FOK判断等级 ,但FOK判断准确性无明显差异。     

哈尼族村社祭司——咪谷

咪谷是哈尼族社会生活中重要角色人物。他既是自然属性的人,又是神灵的化身;他曾经既是行政首长,又是宗教祭司;他是做人的楷模,是村寨生活精神的象征,是人生价值的追求目标。本文阐述咪谷产生的历史背景及条件的基础上,阐明咪谷与莫批在哈尼族社会中地位和不同作用,提出了咪谷精神在当今构建和谐村社中具有重要的现实意义。