In the past, human violence was associated with food shortage, but recently it has increased even in relatively well-fed societies. The reason appears from studies of monkeys under relaxed, spacious conditions and under crowding stress. Uncrowded monkeys have unaggressive leaders, rarely quarrel, and protect females and young. Crowded monkeys (even well-fed) have brutal bosses, often quarrel, and wound and kill each other, including females and young. Crowding has similar behaviour effects on other mammals, with physiological disturbances including greater susceptibility to infections. All this appears to be a regular response to overpopulation, reducing the population before it has depleted its natural resources. Human beings, like monkeys and other mammals, need ample space, and become more violent when crowded. Human history is marked by population cycles: population outgrows resources, the resulting violence, stress and disease mortality cuts down the population, leading to a relief period of social and cultural progress, till renewed population growth produces the next crisis. The modern population crisis is world-wide, and explains the increase of violence even in well-fed societies. The solution to the problem of violence is to substitute voluntary birth control for involuntary death control, and bring about relaxed conditions for a reduced world population. (+info)
An analysis of consultations with the crowd doctors at Glasgow Celtic football club, season 1999-2000.
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OBJECTIVE: To analyse all clinical presentations to the crowd doctors at Scotland's largest football stadium over the course of one complete season. METHODS: A standard clinical record form was used to document all consultations with the crowd doctors including treatment and subsequent referrals. The relevance of alcohol consumption was assessed. RESULTS: A total of 127 casualties were seen at 26 matches, a mean of 4.88 per match. Twenty casualties were transferred to hospital, including one successfully defibrillated after a cardiac arrest. Alcohol excess was a major contributing factor in 26 cases. CONCLUSIONS: The workload of the crowd doctors was very variable and diverse. The social problem of excessive alcohol consumption contributed considerably to the workload. The provision of medical facilities at football grounds means that attendance there is now one of the least adverse circumstances in which to have a cardiac arrest. The study confirmed previous impressions that more casualties are seen at high profile matches. (+info)
Area-level characteristics and smoking in women.
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OBJECTIVES: This study examined whether area-level characteristics are associated with individual smoking behavior among women. METHODS: Analyses included 648 women enrolled as control patients in the Carolina Breast Cancer Study (1993-1996). Smoking and covariate information was obtained from interviews. Area-level characteristics included census block-group education level, poverty, unemployment, car-home ownership, crowding, and, for 431 women, city-level crime rates. RESULTS: In multivariate logistic regression models, no area characteristics were clearly associated with a history of smoking. Among those who had ever smoked, continued smoking was associated with living in low-education areas (odds ratio [OR] = 1.7, 95% confidence interval [CI] = 1.0, 2.9), high-unemployment areas (OR = 1.7, 95% CI = 1.0, 2.8), and high-crime areas (OR = 1.6, 95% CI = 0.8, 3.2). CONCLUSIONS: The present findings are consistent with a growing literature suggesting that area-level social and economic disadvantage influences individual smoking behavior. (+info)
The epidemiology of hepatitis A in Rio de Janeiro: environmental and domestic risk factors.
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A serological study of hepatitis A was carried out in low-income areas scheduled for a major sanitation programme in Rio de Janeiro, Brazil. Blood spots were collected by finger puncture and transported on filter paper, and total antibodies to hepatitis A virus were detected by ELISA. Households were also interviewed to collect information on their environmental conditions and socio-economic status. A generalized linear model using a complementary log-log function was fitted to the data, using the logarithm of age as an explanatory variable to derive adjusted rate ratios (RR). The risk of infection was greater among households with 2-3 members per room (RR = 1.4; 95% CI = 1.04-1.8) or more than three per room (RR = 1.5; 95% CI = 1.2-2.0). People living on hilltops (RR = 1.5; 95% CI = 1.02-2.2), near to open sewers (RR = 1.2; 95% CI = 1.03-1.5) or lacking a kitchen (RR = 1.4; 95% CI = 1.08-1.9) were also at greater risk than others. The number of taps and water-using fittings in the house was associated with a protective effect (RR = 0.9 for each tap; 95% CI = 0.9-0.98). A significant protective association was found with maternal education but not with gender or household income. The results do not suggest a strong association with water quality. Ownership of a ceramic water filter was associated with a protective effect on the margin of significance, but the practice of boiling drinking-water was not, nor was the type of water source used. The results suggest that that the risk of infection with hepatitis A is determined by environmental variables in the domestic and public domains. (+info)
Changes in behaviour, cortisol and lymphocyte types during isolation and group confinement of sheep.
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This experiment compared changes in complex behaviour patterns, adrenal corticosteroid secretion and the numbers of various types of lymphocytes in sheep that were subjected to the stress of confinement. Grazing Merino ewes (n=80 in five replicated experiments) were confined either in groups of four per pen or in total isolation from other sheep. The percentage of CD4+ lymphocytes increased while the percentage of CD8+ lymphocytes decreased over the experimental period. This result was more pronounced in isolated sheep than in grouped sheep. The increase in CD4:CD8 was greater for isolated sheep than for grouped sheep and greater for 2 week sheep than for 3 week sheep. The percentage of CD5+ cells also increased, less so in isolated than in grouped animals. Interpreting these changes as a recovery of immune competence following introduction of a stressor, it is apparent that isolation impaired immune system recovery more severely than group confinement. Physiological and behavioural adaptation over the period were characterized by a decline in the adrenocortical response, resumption of the normal pattern of flocking behaviour and a reduction in motor activity during the test. These findings add to the evidence pointing to the possible correspondence between critical features of the psychoneural, neuroendocrine and immune systems. (+info)
K-selection, alpha-selection, effectiveness, and tolerance in competition: density-dependent selection revisited.
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In the Drosophila literature, selection for faster development and selection for adapting to high density are often confounded, leading, for example, to the expectation that selection for faster development should also lead to higher competitive ability. At the same time, results from experimental studies on evolution at high density do not agree with many of the predictions from classical density-dependent selection theory. We put together a number of theoretical and empirical results from the literature, and some new experimental results on Drosophila populations successfully subjected to selection for faster development, to argue for a broader interpretation of density-dependent selection. We show that incorporating notions of alpha-selection, and the division of competitive ability into effectiveness and tolerance components, into the concept of density-dependent selection yields a formulation that allows for a better understanding of the empirical results. We also use this broader formulation to predict that selection for faster development in Drosophila should, in fact, lead to the correlated evolution of decreased competitive ability, even though it does lead to the evolution of greater efficiency and higher population growth rates at high density when in monotypic culture. (+info)
Risk factors for burns in children: crowding, poverty, and poor maternal education.
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OBJECTIVE: To characterize the presentation of burns in children and risk factors associated with their occurrence in a developing country as a basis for future prevention programs. DESIGN: Case-control study. SETTING: Burn unit of the National Institute of Child Health (Instituto Nacional de Salud del Nino) in Lima, Peru. METHODS: A questionnaire was administered to all consenting guardians of children admitted to the burns (cases) and general medicine (controls) units during a period of 14 months. Guardians of patients were questioned regarding etiology of the injury, demographic and socioeconomic data. RESULTS: 740 cases and controls were enrolled. Altogether 77.5% of the cases burns occurred in the patient's home, with 67.8% in the kitchen; 74% were due to scalding. Most involved children younger than 5 years. Lack of water supply (odds ratio (OR) 5.2, 95% confidence interval (CI) 2.1 to 1 2.3), low income (OR 2.8, 95% CI 2.0 to 3.9), and crowding (OR 2.5, 95%CI 1.7 to 3.6) were associated with an increased risk. The presence of a living room (OR 0.6, 95% CI 0.4 to 0.8) and better maternal education (OR 0.6, 95% CI 0.5 to 0.9) were protective factors. CONCLUSIONS: To prevent burns interventions should be directed to low socioeconomic status groups; these interventions should be designed accordingly to local risk factors. (+info)
Helicobacter pylori infection in rural China: demographic, lifestyle and environmental factors.
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BACKGROUND: Although Helicobacter pylori is one of the most common human bacterial infections worldwide, its mode of transmission is unclear. METHODS: To investigate possible associations between H. pylori infection and demographic, lifestyle, and environmental factors in a rural Chinese population, a cross-sectional survey was administered to 3288 adults (1994 seropositive, 1019 seronegative, 275 indeterminate) from 13 villages in Linqu County, Shandong Province, China. RESULTS: Helicobacter pylori prevalence was elevated for: infrequent handwashing before meals (OR = 1.7, 95% CI: 1.0-3.0), crowding (i.e. sharing a bed with >2 people [OR = 2.3, 95% CI: 1.3-4.2]), washing/bathing in a pond or ditch (OR = 1.5, 95% CI: 1.0-2.4), and medium (OR = 1.6, 95% CI: 1.3-2.0) and low (OR = 2.3, 95% CI: 1.9-2.9) compared to high village education level, and reduced for never being married or divorced (OR = 0.4, 95% CI: 0.2-1.0). There was also a suggestion that source of drinking water, especially water from a shallow village well might be related to H. pylori seropositivity. There was no evidence of an association between H. pylori prevalence and alcohol or tobacco use, raw fruit and vegetable intake, or individual social class measures. CONCLUSIONS: The results of this study suggest that person-to-person transmission is the most plausible route of H. pylori infection in this rural Chinese population, but waterborne exposures deserve further investigation. (+info)