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)     

Menstruation and crime: A critical review of the literature from the clinical criminology perspective

The authors review the literature on the relationship between menstruation and crime, focusing upon the methodological limitations of these studies in the broader context of criminological and menstruation research. Based on this review, they conclude: the present state of scientific knowledge is such that it is unknown whether there is an association between any phases of the menstrual cycle and crime; there is no evidence linking fluctuations in reproductive hormones to criminal behavior; and, this lack of scientific knowledge is so glaring that evidence regarding menstruation and crime should not be admissible in criminal trials.     

Five-month-old infant recall and utilization of temporal organization

The ability of 5-month-old infants to recall temporal information and utilize temporal organization was investigated in two experiments. Infants were trained to fixate a hierarchically structured or an unstructured sequence of stimuli which appeared in four spatial positions. In the first study, the number of infants who demonstrated correct recall through the third serial position of a sequence was significantly better then would occur by chance. In the second study, infants given structured sequences showed a significant increase in the number of correct fixations across trials, and they recalled across serial positions better in structured sequences. Also, accuracy of recall in both studies for the middle serial positions was related to hierarchical organization following 8-unit structured sequence training but was at chance level following unstructured sequence training. Results of both studies were interpreted within a temporal organizational framework: Infants appear to utilize organization within sequences of information.     

Gender, relational role orientation, and affinity for animal rights

Research based mainly on non-national samples reports a greater affinity for animal rights among women than men, and proposes a greater relational role orientation among women that emphasizes caring for others to explain this difference. Using a recent national sample comprised of 11% African American and 89% white American respondents, we find that a relational role orientation fails to account for women’s greater support of animal rights. It does provide minor help in distinguishing animal rights advocates from nonadvocates, but only among women and only on one of two measures of animal rights support. We conclude by proposing women’s structural locations as well as the interplay between these locations and women’s role socialization as alternate explanations for gender differences in affinity for animal rights.     

Stimulus-independent thought depends on central executive resources

Stimulus-independent thoughts (SITs) are streams of thoughts and images unrelated to immediate sensory input. Four experiments examined the contribution of aspects of working memory to production of SITs. In Experiments 1 and 2, interventions that were targeted on, respectively, phonological and visuospatial components of working memory both interfered with production of SITs, but there was evidence that these tasks also made demands on central executive resources. Experiments 3 and 4 specifically examined the hypothesis that production of SITs and control of nonproceduralized tasks both depend on central executive resources, and so should show mutual interference. In Experiment 3, prior practice on pursuit rotor and memory tasks reduced the interference with SITs from concurrent task performance. In Experiment 4, randomness within a task involving random-number generation was less when SITs were being produced concurrently than it was when they were not. The results suggest that production of SITs depends on central executive resources.     

Graphics in written directions: Appreciated by readers but not writers

This series of studies investigated the ability of literate adults to exploit communications options that are available to writers but have no counterpart in speech. Specifically it examined people's use of sketches when giving written directions to help a stranger cross town. When writing an informal letter to a friend most directions were given in prose paragraph style (Experiment 1). Almost no-one included a sketch, even if given a street map as an aid. Yet most subjects could draw adequate sketch maps (Experiment 2), and everyone said yes when asked whether they would include a sketch in a letter. So the previous choices were not constrained either by graphic skill or by judgements concerning the appropriateness of a sketch, When people were asked to 'design' the back page of a leaflet they still did not include a sketch (Experiment 3). Experiment 4 showed that any bias in the instructions was towards rather than against the use of sketches. The need to generate the sketch was removed in Experiment 5 where subjects composed the leaflet page from pre-formed sections that included alternative routes in both words and diagrams. Nearly all subjects now included a sketch in their directions. In case subjects previously, in haste, had not considered the possibility of including a sketch map, they were made aware of the drawing option by rating the usability of route information in a variety of communication styles immediately before writing their own directions (Experiment 6). People rated directions that included diagrams as significantly more usable, but still most subjects did not include a sketch in the directions they gave. So the communication styles that readers recognized as successful were not determining their choices as writers. It is suggested that, when giving written directions, inexperienced writers rely too heavily on how they would respond as speakers.     

Distributive justice and the minnesota health access initiative

As I have suggested, from the perspective of distributive justice MinnesotaCare's reforms are inadequate. But to coin (and alter slightly) a phrase of Kant's, if its authors do not deserve our moral esteem, perhaps they do merit our encouragement, and it is on a note of the latter that I will conclude. MinnesotaCare is an experiment in systemic incremental change being performed in a complex health care system, the only true laboratory for such an experiment. For this reason, it will provide us important information concerning the ethics, economics, [and] the politics of health care reform while improving the position of some Minnesotans in a significant way. Thus, while MinnesotaCare is susceptible to forceful moral criticism, as an experiment in reform it holds out the promise of providing us some of the data necessary for discovering a just solution.