Male-female differences in effects of parental absence on glucocorticoid stress response

This study examines the family environments and hormone profiles of 316 individuals aged 2 months-58 years residing in a rural village on the east coast of Dominica, a former British colony in the West Indies. Fieldwork was conducted over an eight-year period (1988–1995). Research methods and techniques include radioimmunoassay of cortisol and testosterone from saliva samples (N=22,340), residence histories, behavioral observations of family interactions, extensive ethnographic interview and participant observation, psychological questionnaires, and medical examinations. Analyses of data indicate complex, sex-specific effects of family environment on endocrine function. Male endocrine profiles exhibit greater sensitivity to presence of father than do female endocrine profiles. Father-absent males tend to have (a) low cortisol levels during infancy, (b) high or abnormal cortisol profiles during childhood and adolescence, and (c) high cortisol and low testosterone levels during adulthood compared with those of males raised with a resident father. These results indicate that early family environment has significant effects on endocrine response throughout male life histories. Mark V. Flinn is an Associate Professor of Anthropology at the University of Missouri, Columbia. He studies family relationships, endocrine stress response, and child health from a mix of evolutionary and developmental psychology perspectives. Robert J. Quinlan is a graduate student in the Department of Anthropology at the University of Missouri, Columbia. His interests include time allocation, family relationships, and medical anthropology. He is planning a long-term ethnographic study of cross-cousin marriage among the E’nyepa of Venezuela. Mark T. Turner is a graduate student in the Department of Anthropology at Northwestern University. He studies covariance of mother and infant hormone and immune function in naturalistic settings using assays from saliva and breast milk samples and ethnographic observations. Seamus A. Decker is a graduate student in the Department of Anthropology at Emory University. He has studied social factors associated with daily variations of salivary cortisol and testosterone levels among males in a Caribbean village. He is currently investigating levels of stress in rural and urban populations in Botswana. Barry G. England is an Associate Professor of Pathology and director of the ligand assay laboratories of the University of Michigan Hospitals. His primary interests concern reproductive endocrinology.     

Over-invasion in a freshwater ecosystem: newly introduced virile crayfish (Orconectes virilis) outcompete established invasive signal crayfish (Pacifastacus leniusculus)

Biological invasions are a key threat to freshwater biodiversity, and identifying determinants of invasion success is a global conservation priority. The establishment of introduced species is predicted to be hindered by pre-existing, functionally similar invasive species. Over a five-year period we, however, find that in the River Lee (UK), recently introduced non-native virile crayfish (Orconectes virilis) increased in range and abundance, despite the presence of established alien signal crayfish (Pacifastacus leniusculus). In regions of sympatry, virile crayfish had a detrimental effect on signal crayfish abundance but not vice versa. Competition experiments revealed that virile crayfish were more aggressive than signal crayfish and outcompeted them for shelter. Together, these results provide early evidence for the potential over-invasion of signal crayfish by competitively dominant virile crayfish. Based on our results and the limited distribution of virile crayfish in Europe, we recommend that efforts to contain them within the Lee catchment be implemented immediately.     

Concentration of Reovirus and Adenovirus from Sewage and Effluents by Protamine Sulfate (Salmine) Treatment

Protamine sulfate was employed to recover reoviruses, adenoviruses, and certain enteroviruses from sewage and treated effluents; 50- to 400-fold concentration of viral content was achieved.     

Ruthenium Red inhibits the activation of pyruvate dehydrogenase caused by positive inotropic agents in the perfused rat heart.

The increases in the amount of active, non-phosphorylated, pyruvate dehydrogenase caused by positive inotropic agents (from a control value of about 10%, to 40% of total enzyme) in the perfused rat heart could be completely blocked by prior perfusion with 2.5 micrograms of Ruthenium Red/ml. A similar increase caused by 5 mM-pyruvate was not blocked. This concentration of Ruthenium Red caused a 25% decrease in contractile force of hearts perfused in the absence of positive inotropic agents; however, in their presence the contractile force reached the same value in the absence or presence of Ruthenium Red. Neither control nor stimulated phosphorylase a content was affected by Ruthenium Red. Verapamil (0.1 microM) also decreased control contraction (by 40%), but did not block the activation of pyruvate dehydrogenase caused by a rise in extracellular [Ca2+]. The results support the hypothesis that positive inotropic agents activate pyruvate dehydrogenase in rat heart by increasing intramitochondrial [Ca2+].     

A requirement for Ca2+ in the extraction of O2-evolving Photosystem 2 preparations from the cyanobacterium Anacystis nidulans

Ca2+ has been shown to be essential for the retention of maximal O2-evolving activity in Photosystem 2 particles extracted by using dodecyldimethylamine oxide from Anacystis nidulans thylakoids. The effect cannot entirely be mimicked by using Mg2+. Ca2+ stimulates electron transport from diphenylcarbazide to 2,6-dichloroindophenol catalysed by lead-inhibited cation-free preparations, showing the presence of two cation-binding sites in these particles. Photosystem 2 preparations extracted in Ca2+-containing buffer show the presence of three polypeptides at mol. wt. 30000, 33000 and 36000, which are absent or much decreased in preparations extracted in Mg2+-containing buffer. The calmodulin antagonist chlorpromazine inhibits activity of the Photosystem 2 preparation, suggesting the presence of a Ca2+-binding protein.     

Four Years' Experience with Indwelling Silastic Cannulae for Long-term Peritoneal Dialysis

Indwelling silicone rubber cannulae have been used for peritoneal dialysis in 41 uraemic patients for periods of up to 46 months. The simplicity of this treatment is particularly suited to patients awaiting transplantation.     

Elucidation and optimization of the medium constituents controlling antibiotic production by the cyanobacterium Nostoc muscorum.

A study has been made to determine which nutrient factors control antibiotic production by the cyanobacterium, Nostoc muscorum. A two-phase approach was employed using a factorial method to explore the response surface and a steepest ascent method to climb the response surface to the region of the optimum. It was found that nitrate and iron were the factors significantly affecting antibiotic production; 26.4 mM nitrate and 6 microM iron were the optimal concentrations for maximizing antibiotic production by N. muscorum.