The rhythmic patterning of man's biochemical, physiological, and psychological behavior and the temporal relationships among various functions are the province of chronobiology. Citing animal and human studies, the author documents the progress of this new science and poses complex questions that it may answer about human behavior. (Editor/SJL)

A review of experiments which demonstrate the release of ATP from skeletal muscle, cardiac muscle, and active brain tissue. Effects of exogenously applied ATP to brain tissue are discussed in relation to whole body exercise. (Author/SA)

Prospectively examined caloric intake, resting metabolic rate (RMR), leisure time physical activity, and sensitivity and preference for sweet taste in seven female smokers during normal smoking, complete cessation, and resumption of smoking. Findings suggest that smoking cessation may cause rapid change in energy balance which is quickly reversed…

A study of eight normal right-handed men demonstrates widespread significant decreases in brain glucose metabolic rate (GMR) following learning a complex computer task, a computer game. Correlations between magnitude of GMR change and intelligence scores are also demonstrated. (SLD)

The search for the meaning of the word shunt as it is used in the hexose monophosphate shunt system is described. A review of the literature on this pathway is included. (KR)

The role of psychological interpretations in the relationship between low socioeconomic status (SES) and physiological responses was tested. One hundred high school students (ages 15-19) watched videos of ambiguous and negative life situations, and were interviewed about their interpretations. Lower SES was associated with greater threat…

This study examines the effects of self-tested blood alcohol concentration (BAC) feedback, from personal hand-held breathalyzers, on the accuracy of BAC estimation. Using an e-mail prompted web-based questionnaire, 19 participants were asked to report both BAC estimates and subsequently measured BAC levels over the course of 27 days. Results from…

Longitudinal neurobehavioral development was examined in 237 fetuses of low-risk pregnancies from 2 distinct populations-Baltimore, Maryland, and Lima, Peru-at 20, 24, 28, 32, 36, and 38 weeks gestation. Data were based on digitized Doppler-based fetal heart rate (FHR) and fetal movement (FM). In both groups, FHR declined while variability,…

Persons who stutter often report their stuttering is influenced by emotional reactions, yet the nature of such relation is still unclear. Psychophysiological studies of stuttering have failed to find any major association between stuttering and the activity of the sympathetic nervous system. A review of published studies of heart rate in relation…

For some time it has been claimed that trisomic cells are more sensitive to oxidative stress since there is an imbalance in hydrogen peroxide metabolism due to an increase in superoxide dismutase (SOD) catalytic activity. We designed the present study to assess activity levels of antioxidant enzymes [superoxide dismutase (SOD), glutathione…

Metabolic control analysis has contributed to the rapid advance in our understanding of metabolic regulation. However, up to now this topic has not been covered properly in biochemistry courses. This work reports the development and implementation of a practical lesson on metabolic control analysis (MCA) using modeling and simulation. The…

Our goal in this study was to compare cardiac autonomic control at rest between 50 individuals with Down syndrome and 24 control participants without disabilities. Resting autonomic function was assessed using analysis of heart rate variability. Participants with Down syndrome had reduced total heart rate variability, which indicates possible…

This brief presents the findings of a study that examined the effects of "allostatic load" on children in poverty at age 9 and 13. "Allostatic load" refers to the measurement of the cumulative wear and tear on the body that results from experiencing stress. Research shows that high allostatic load in childhood is associated with long-term…

The emphasis in public health on lifestyle physical activity in recent years has focused attention on the promotion of lifetime physical activity as the primary objective of physical education. If used properly, physical activity and physical fitness assessments can enhance individual promotion of physical activity and also provide valuable…

Socio-emotional behaviour is in part sex-related in humans, although the contribution of the biological and socio-cultural factors is not yet known. This study explores sex-related differences during the earliest communicative exchange, the neonatal imitation in 43 newborn infants (3-96 hours old) using an index finger extension imitative gesture.…