Ecological determinants of women's status among hunter/gatherers

Women's status in preindustrial communities has been the focus of a number of studies in the past two decades. However, very few of these studies deal exclusively with hunter/gatherers, and none of the hunter/gatherer studies combine empirical tests with explanations. Because of a number of differences with settled agricultural villagers, hunter/gatherers can be viewed as the focus of distinctive substantive ecological theory. A cross-cultural materialist approach to the problem of why women's status is high among some hunter/gatherers and low among others indicates that several factors are strongly related to differences in women's status. Frequent and severe resource stress is the most strongly associated with low female status in the domestic and political domain, while warfare exerts an independent but lesser effect. The importance of hunting constitutes a third and still more weakly associated variable. Thus, women's political and domestic status among hunter/gatherers predominantly appears to have resulted from techno-ecological conditions. In contrast, technoecological conditions appear to have had no strong influence on women's status in ritual roles, including shamanism. Several possible ways that women's status might be linked to techno-economic conditions are proposed. The results of this study demonstrate that Leacock's assumptions of systematic bias in the ethnographic record, and of ubiquitous female equality among band level societies are unjustified.     

Neuromuscular adaptations to training

The purpose of this experiment was to determine whether there is a central adaptation to resistance overload. The right adductor pollicis muscle of each subject was trained with either voluntary (n = 9) or electrically stimulated contractions (n = 7), the contralateral muscle acted as an internal control, and seven other subjects acted as a control group. Training was the same in both groups: 15 contractions at 80% maximal voluntary contraction (MVC), 3 days/wk for 5 wk. Trained muscles in both groups increased MVC by approximately 15% (voluntary, P less than 0.01; stimulated, P less than 0.05). There was a small (9.5%) but significant (P less than 0.05) increase in MVC of the untrained muscles in the voluntary group. MVC did not change in the control group. Maximal electromyogram (EMG) was highly reproducible pre-to posttraining in the control group (r = 0.92, slope = 0.995) and did not change pre- to posttraining in the trained groups. Sensory adaptation to training caused a reduction in force sensation in the stimulated group (P less than 0.05) but not in the voluntary group. Because there was a small increase in MVC of the untrained muscle of the voluntary group (9.5%, P less than 0.05) but not in the stimulated group, it is possible that there is a central motor adaptation, but it is not manifested in increased neural drive (EMG). Moreover, this central adaptation may be responsible for the decrease in force sensation that follows training.     

Potentiation of amphetamine-induced hyperactivity by acute but not by chronic para-chlorophenylalanine treatment in the rat.

Acute pre-treatment with para-chlorophenylalanine potentiated amphetamine-induced hyperactivity. Chronic pre-treatment with para-chlorophenylalanine failed to produce potentiation of the amphetamine effect. Activity levels were slightly depressed following acute para-chlorophenylalanine treatment alone and significantly depressed following chronic para-chlorophenylalanine alone. The findings indicate that the acute effects of a drug can be different from its chronic effects. The data may be consistent with the notion that a gradual adjustment to para-chlorophenylalanine took place with time.     

Metabolic consequences of limited substrate anion permeability in brown fat mitochondria from a hibernator,the golden hamster

Brown fat mitochondria obtained from a hibernator, the golden hamster, were investigated in order to elucidate the significance of membrane permeability for metabolic functioning at different temperatures. The mitochondria were shown to have active permeases for phosphate and pyruvate, but very poorly developed permeases for di- and tricarboxylate substrate anions. This was shown with both osmotic swelling techniques and respiration-driven uptake studies. It was shown that the very limited malate permeation observed was compatible with it being a non-carrier-mediated diffusion process. The role of malate transport in supporting fatty-acid oxidation in vitro as a function of temperature was studied in detail. The results support our earlier suggestion that physiologically pyruvate carboxylase probably functions to generate oxaloacetate when high concentrations of condensing partner are needed during thermogenesis. They may also explain earlier observations that acetate was produced from palmitoyl-carnitine at low temperatures even when malate was present; this is here shown to be due to the limited malate permeability at these low temperatures. Thus, even at the body temperature of the hibernating hamster (4–5°C), brown fat is probably able to combust fatty acids totally.     

Course of HIV-I infection in a cohort of homosexual and bisexual men: an 11 year follow up study.

OBJECTIVE--To characterise the natural history of sexually transmitted HIV-I infection in homosexual and bisexual men. DESIGN--Cohort study. SETTING--San Francisco municipal sexually transmitted disease clinic. PATIENTS--Cohort included 6705 homosexual and bisexual men originally recruited from 1978 to 1980 for studies of sexually transmitted hepatitis B. This analysis is of 489 cohort members who were either HIV-I seropositive on entry into the cohort (n = 312) or seroconverted during the study period and had less than or equal to 24 months between the dates of their last seronegative and first seropositive specimens (n = 177). A subset of 442 of these men was examined in 1988 or 1989 or had been reported to have developed AIDS. MAIN OUTCOME MEASURES--Development of clinical signs and symptoms of HIV-I infection, including AIDS, AIDS related complex, asymptomatic generalised lymphadenopathy, and no signs or symptoms of infection. MEASUREMENTS AND MAIN RESULTS--Of the 422 men examined in 1988 or 1989 or reported as having AIDS, 341 had been infected from 1977 to 1980; 49% (167) of these men had died of AIDS, 10% (34) were alive with AIDS, 19% (65) had AIDS related complex, 3% (10) had asymptomatic generalised lymphadenopathy, and 19% (34) had no clinical signs or symptoms of HIV-I infection. Cumulative risk of AIDS by duration of HIV-I infection was analysed for all 489 men by the Kaplan-Meier method. Of these 489 men, 226 (46%) had been diagnosed as having AIDS. We estimated that 13% of cohort members will have developed AIDS within five years of seroconversion, 51% within 10 years, and 54% within 11.1 years. CONCLUSION--Our analysis confirming the importance of duration of infection to clinical state and the high risk of AIDS after infection underscores the importance of continuing efforts both to prevent transmission of HIV-I and to develop further treatments to slow or stall the progression of HIV-I infection to AIDS.     

A larval ascaridoid nematode from Queensland scallops

Cannon L. R. G. 1978. A larval ascaridoid nematode from Queensland scallops. International Journal for Parasitology8: 75–80. The morphology of a fourth stage larval ascaridoid found in Amusium balloti is given with observations on the double nature of the excretory system. The infection rate was 5.6% with rarely more than one worm per scallop. No seasonal change in incidence was detected and no change in incidence with host size. The systematic position, possible life cycle and economic importance of the worm are discussed.