Shortening of the QT interval of the EKG is associated primarily with increased ventricular contractility rather than heart rate

The objective of this study was to gather direct evidence on whether the duration of the QT interval relates primarily to heart rate or to ventricular contractility. The electrocardiographic and cardiodynamic consequences of electrical stimulation (15 V, 5 ms, 10Hz) of various intrathoracic sympathetic efferent neuronal structures were studied in 10 anesthetized mongrel dogs. Stimulation of efferent sympathetic axons in the right intraganglionic nerve, which innervates the sinoatrial node, induced tachycardia (110±5 - 133±6 bpm; p<0.01) without significantly altering right or left ventricular intramyocardial ventricular chamber pressures. The QT interval, as determined by leads I, II and III of the EKG and a transthoracic lead, was not affected by this intervention (310±8 - 302±ms). Increasing heart rate to a similar degree (111±3 - 131±3 bpm) by right atrial pacing did not induce changes in the QT interval. When right (23±3 - 49±8 mm Hg; p<0.01) and left (81±10 - 127±19 mm Hg; p<0.01) ventricular forces were augmented without concomitant increases in heart rate by stimulating efferent sympathetic axons in the left caudal pole cardiopulmonary nerve the QT interval shortened (322±11 - 290±12 ms; p<0.01). Only when an efferent sympathetic nerve, that contains fibers destined for both the sinoatrial node and the ventricles was stimulated did both heart rate and ventricular contractility augment and QT shorten (318±10 - 290±11 ms; p<0.01). These results indicate that QT interval shortening induced by efferent sympathetic neurons is primarily associated with augmentation of ventricular contractility rather than heart rate.     

Effects of transient coronary artery occlusion on canine intrinsic cardiac neuronal activity

In order to further elucidate the regulatory function of canine epicardial neurons, the effects of transient coronary artery occlusion on their spontaneous activity was studied. Fifty-eight individual, spontaneously active units were identified by means of their action potential configurations in specific loci of atrial and ventricular epicardial fat of 10 anesthetized dogs. The activity of 49 of the units was modified by one minute of coronary artery occlusion. Twenty-four of the 49 responding units exhibited increased activity and 37 decreased activity during coronary artery occlusions. Activity changes were sometimes, but not always, associated with decreased left ventricular intramyocardial systolic pressure. During reperfusion, the activity of 6 units was increased compared to control levels, even though ventricular pressures remained the same. Following acute decentralization, 48% of previously active units generated spontaneous activity; the activity of 89% of these was altered during coronary artery occlusion despite the fact that overall cardiodynamics were unchanged. Following hexamethonium administration, the activity generated by 9 of 10 spontaneously active units was modified by coronary artery occlusion. It is concluded that transient coronary artery occlusion can modify the activity generated by intrinsic cardiac neurons, such modification involving central and peripheral neuronal interactions.     

Looking for Whitehead

Saul Kripke in his revolutionary and influential series of lectures from the early 1970s (later published as the book Naming and Necessity) famously resurrected John Stuart Mill's theory of proper names. Kripke at the same time rejected Mill's theory of general terms. According to Kripke, many natural kind terms do not fit Mill's account of general terms and are closer to proper names. Unfortunately, Kripke and his followers ignored key passages in Mill's A System of Logic in which Mill enunciates a sophisticated and detailed theory of natural kind terms that anticipates and is in some ways superior to Kripke's.     

Blinding me with (queer) science: religion, sexuality, and (post?) modernity

This essay brings to bear insights from continental philosophers Michel Foucault and Judith Butler on the science of (homo)sexuality and, more importantly, the desire to use such science to resolve contemporary conflicts over homosexuality’s acceptability. So-called “queer science” remains deeply beholden to modern notions of sex, gender, and sexuality, the author argues, a schematic that its premodern (Christian) roots further denaturalize. The philosophical insights drawn from this analysis are then applied to the controversy over homosexuality within global Christianity that often pits the “backward” former colonies against the “modern” west.     

Sexual Motives: Cultural,Evolutionary, and Social Psychological Perspectives

Recently, scholars from a variety of disciplines have begun to investigate passionate love, sexual desire, and sexual behavior. Specifically, they have started to ask such questions as: “Why do young men and women engage in sexual liaisons?” “Why do they avoid such encounters?” Unfortunately, in attempting to answer such questions, scholars have generally focused on surveys and experiments within their own disciplines and have accorded scant attention to the discoveries of other disciplines. In this paper, we will begin by discussing three theoretical perspectives that have had the most to say about why young people seek out (or avoid) sex—cultural psychology, evolutionary psychology, and social psychology (where theorists often take a biopsychosocial approach). Then, we will (1) describe the many scales that have been used to assess sexual motives, and (2) review the multidisciplinary data which has been assembled in an attempt to answer the questions as to why people seek out (or avoid) sexual activity. Unfortunately, almost all this research was conducted by Western researchers, investigating the attitudes and behavior of young American men and women, who were heterosexual. (Alas, the wider-ranging data one would wish to consider is as yet only rarely available.) Through this multi-disciplinary synthesis, we hope to demonstrate the impact of culture, social experience, and biological imperatives in shaping young men’s and women’s motives for engaging in sexual encounters and provide a sort of “encyclopedia” of sexual motives measures and research for future scholars.     

ADHD and aggression as correlates of suicidal behavior in assaultive prepubertal psychiatric inpatients

Forty-three psychiatrically hospitalized prepubertal children were assessed regarding their assaultive and suicidal behaviors. These children were subsequently classified into two groups, assaultive/suicidal (AS) and assaultive-only (AO). AS children had higher aggression and suicidal-scale scores, but not higher depression scores, and were more likely to be diagnosed with ADHD. ADHD, child's aggression, and maternal depression and state anger accounted for 33% of the variance in suicidal-scale scores. Aggression mediated the relation between ADHD and suicidal behavior. Differences in symptom pattern between these two subtypes of assaultive inpatient children are interpreted as a basis for distinctive screening procedures.     

Posttraumatic Stress Disorder Symptom Structure in Chinese Adolescents Exposed to a Deadly Earthquake

This present study examined the structure of posttraumatic stress disorder (PTSD) symptoms in a large sample of Chinese adolescents exposed to a deadly earthquake. A total of 2,800 middle school students aged 12 to 18 years participated in the study 6 months after the “Wenchuan Earthquake”. Results of confirmatory factor analysis indicated that a five-factor intercorrelated model composed of intrusion, avoidance, numbing, dysphoric arousal, and anxious arousal, fit data significantly better than both the four-factor numbing model King et al. (Psychological Assessment 10:90–96, 1998) and the four-factor dysphoria model Simms et al. (Journal of Abnormal Psychology 111:637–647, 2002). Further examination of the external convergent and discriminant validity revealed that except for the dysphoric arousal factor, the remaining four PTSD factors yielded significantly different correlations with external measures of anxiety vs. depression. The findings add to the limited literature on the factor structure of PTSD in youths and on the five-factor PTSD model. In addition, they provide more detail into the latent psychopathological processes of PTSD, and inform the forthcoming DSM-5.     

Development and Validation of the Parental Authority Questionnaire – Revised

Baumrind's conceptualization of parenting style has influenced research and theorizing about child-rearing for more than 30 years, yet few clinical applications of this work have been realized. The purpose of this study was to examine the psychometric properties of a parenting style measure, the Parental Authority Questionnaire – Revised (PAQ-R). This project furthered the development and validation of the instrument by examining the factor structure, internal consistency, test-retest reliability, and convergent validity of the PAQ-R in a large, ethnically and socioeconomically diverse sample. The factor structure and reliability of the PAQ-R was modest, but generally within the acceptable range. Specifically, the Authoritarian and Permissive subscales of the PAQ-R had modest reliability and convergent validity; these PAQ-R subscales correlated with relevant subscales of the Parenting Scale and the Parent–Child Relationship Inventory. By contrast, the Authoritativeness subscale had poorer psychometric properties when used in lower SES, primarily African American populations. While African American mothers in the sample reported being more Permissive than did Caucasian mothers, these differences disappeared after controlling for income and maternal education. By contrast, African American mothers continued to report more Authoritarian attitudes even after controlling for income and maternal education.     

Word production deficits in schizophrenia

Fronto-cerebellar circuitry is implicated in word production. Data suggest that the cerebellum is involved in word search, whereas the prefrontal cortex underlies the selection of words from among competing alternatives. We explored the role of search and selection processes in word production deficits in schizophrenia patients. In Experiment 1, patients were impaired in a verb generation task under both high and low selection conditions but were more impaired in the high selection condition. In Experiment 2, when the difficulty level of search and selection conditions was equated in a word stem completion task, patients were only impaired in the search condition. Word search deficits underlie word production problems in schizophrenia, and may involve fronto-cerebellar dysfunction.