Human Ecology Research Research Articles

Is there a role for culture in human behavioral ecology?

Most research in human behavioral ecology has been acultural, which raises the question of how best to incorporate the concept of culture into this approach. A necessary step in this direction is to pare the culture concept down to its ideational elements, excluding behavior and its material products (Durham 1991; Geertz 1973; Keesing 1974). The cultural and reproductive success hypothesis, though empirically successful (Irons 1993), is not a model for all of culture because of widespread discrepancies between behavior and culture to which it does not call attention. Cultural transmission models are also weakened by such discrepancies, but, more importantly, such models are most relevant to phenomena different from those central to human behavioral ecology. A better way to incorporate culture into human behavioral ecology is to see it as the context of human action and as a tool people use in social manipulation. The study of signal systems is a key to an understanding of social manipulation and to the incorporation of culture into human behavioral ecology. Examples of the manipulation of culture for reproductive benefit include Yanomamö kin term manipulation (Chagnon 1988), incest rules (Thornhill 1990, 1991), and the derogation of sexual competitors (Buss and Dedden 1990). The human behavioral ecological study of social manipulation in cultural contexts needs to be expanded. Two phenomena that might shed light on such manipulation are the Rashomon effect and the audience effect.

Pathogenic potential of lactobacilli

Lactobacilli are often considered to be commensal or beneficial participants in human microbial ecology and considerable research is being carried out into the effects of the use of lactobacilli as additives in both human and animal diets. However, lactobacilli also cause some human diseases (e.g. dental caries, rheumatic vascular disease, septicaemia and infective endocarditis (IE)), and have recently been identified as potential emerging pathogens in elderly and immunocompromised patients, particularly those receiving broad spectrum antibiotic therapy. The identification of potential pathogenic traits amongst lactobacilli will therefore facilitate the use of the organisms for probiotic purposes. The ability to aggregate human platelets is considered to be a possible pathogenic trait in the progression of IE. A comparison of bacterial cell surface properties amongst L. rhamnosus strains showed that platelets were aggregated by 5 5 IE strains and 8 16 laboratory strains. For the L. paracasei subsp. paracasei strains the respective numbers were 2 5 and 2 9 . However two strains, morphological mutants of a non-aggregating strain, which had been re-isolated after passaging through rats were found to aggregate platelets. No loss of aggregating function occured on extensive subculturing of IE strains. Aggregation also occurred with 11 14 strains for five other species, namely, Lactobacillus acidophilus, Lactobacillus fermentum, Lactobacillus oris, Lactobacillus plantarum and Lactobacillus salivarius, with each species being represented indicating that the property is not uncommon in the genus. A comparison of IE and oral isolates of L. rhamnosus and L. paracasei subsp. paracasei and seven other Lactobacillus species, has shown that the binding of both fibronectin and fibrinogen by lactobacilli is greatly increased, up to 50 fold, when the pH is reduced from 7.0 to 5.0. Re-exposing the lactobacilli to a neutral pH environment releases most of the bound proteins, but the amount still remaining bound to the cell is several times more than is bound at neutral pH. Lactobacilli will also bind to the proteins that make up the extracellular matrix of endothelial cells. Lactobacilli bound significantly better to collagen types I and V than to types III and IV ( p<0.01). Further, strains isolated from IE cases, particularly L. rhamnosus strains, bound significantly better to types I and V than did ‘normal’ strains ( p<0.02). Type V collagen has been demonstrated at the sites of endothelial damage. Thus the binding of lactobacilli, particularly L. rhamnosus to these collagen types may be of importance in the early stages of colonization of the damaged heart valve. The research therefore suggests that lactobacilli being considered for probiotic purposes should be screened for these potentially pathogenic traits.

An Introduction to Human Ecology Research on Agricultural Systems in Southeast Asia

An Introduction to Human Ecology Research on Agricultural Systems in Southeast Asia

An Introduction to Human Ecology Research on Agricultural Systems in Southeast Asia. Edited by A. Terry Rambo and Percy E. Sajise. Los Banos, Laguna, Philippine Islands: University of the Philippines at Los Banos, 1984. xviii, 327 pp. N.p.

An Introduction to Human Ecology Research on Agricultural Systems in Southeast Asia. Edited by A. Terry Rambo and Percy E. Sajise. Los Banos, Laguna, Philippine Islands: University of the Philippines at Los Banos, 1984. xviii, 327 pp. N.p.

Essays in Human Ecology--2.

This collection of essays by various authors is devoted to theoretical and methodological aspects of the study of human ecology research techniques and computer programs. The topics covered include the identification and delineation of ecological community areas computerized analysis of census tract data census tract comparability the estimation of inter-censal migration for small areas socio-spatial contours for ecological analysis ecological determinants of migration within census tracts and consolidating 1980 census tract data from three sets of census tapes. The geographic focus of the studies is on the United States.

Progressive contextualization: Methods for research in human ecology

Theoretically or practically significant research results concerning transitory as well as persistent phenomena can be obtained by human ecologists while avoiding commitment to long-term, expensive projects, rigid frameworks, traditional disciplinary goals, and unwarranted assumptions about the stability and purposiveness of units or systems. The procedures to be followed, as illustrated by research on people-forest interactions in East Kalimantan, involve a focus on significant human activities or people-environment interactions and the explanation of these by their placement within progressively wider or denser contexts. Guides for progressively contextualizing activities or interactions include a rationality principle, comparative knowledge of contexts, and the principle of pursuing the surprising.

Progressive contextualization: Methods for research in human ecology

Progressive contextualization: Methods for research in human ecology

Models and Muddles: An Ecological Examination of High School Crime Rates

Recently, human ecological research has made increasing use of causal modeling in the attempt to understand aggregate-level social processes. This approach has great appeal because it helps make hypotheses explicit, provides a convenient way of structuring the application of statistical controls, allows the representation of complexity in the relations among variables, and, if strong assumptions are plausible, makes possible weak probes of causal hypotheses using only correlational evidence. The present report critically ex amines the usefulness of the path analytic approach in human ecology by exploring the rate of high school crimes reported to the police and providing some tests of the plausibility of the assumptions underlying the research strategy. It is concluded that, in this and similar studies, confidence in the interpretation of results is difficult to achieve. Alternative approaches may be more fruitful and merit the attention of research policy makers.

The Philippine Earthquake and Tsunami Disaster: A Reexamination of Behavioral Propositions*

The Philippine Earthquake and Tsunami Disaster: A Reexamination of Behavioral Propositions*

Tolerance for Pain, Extraversion and Neuroticism

It may be deduced from Eysenck's (1957, 1960a) theory of personality that pain tolerance should be positively related to extraversion (E) and negdtively to neuroticism (N). Extraverted Ss are postulated to develop inhibition/ satiation more quickly, and dissipate it more slowly; prolonged pain sensations should thus be inhibited more quickly and strongly in extraverts, leading to diminished pain sensations. Furthermore, as Beecher (1959) has pointed out, physiological pain sensations are always accompanied by the app7ehe?zsion of fatare pain, which may be conceived as a conditioned fear (anxiety) response which sumrnates with the physiological pain. Extraverts are posited to condition less well, and would therefore not develop this component of the total pain to the same extent as introverts. The prediction relating to N is perhaps less secure; it rests on the assumption that the strength of the autonomic reaction to pain stimulation would be likely to be related directly to N, which is conceived of in terms of autonomic lability (Eysenck, 1960b). This autonomic reaction would be expected to summate with the physiological pain due to the stimulus. Thirry volunteer university students, the experimental group, were given the Maudsley Personality Inventory as a measure of E and N (Eysenck, 1959), as well as the Rotating Spiral After-effect test which is an objective measure of E (Eysenck, 1960a). Ss' foreheads were blackened with India ink, and they were then subjected to heat stimulation by a thermo-stimulator modelled after the description given by Hardy, Wolff, and Goodell ( 1952 ). The radiation intensity was set at 166 w, and Ss were instructed to report the onset of pain, which is usually characterized by a sharp prick following a sensation of warmth. They were then to try to tolerate the pain for as long as they could. Pain tolerance was the number of seconds from the first report of pain to the final withdrawal. All Ss reported pain within 3 to 5 sec. after exposure. There appears to be a habituation effect after about 12 sec. of pain, such that, if pain could be tolerated for this long, Ss reported that they felt it could be endured indefinitely. Five Ss tolerated the pain for 60 sec., after which the trial was terminated. A time limit of 20 sec. was finally set because of blisters which began to develop after about 8 sec. exposure. When Ss are divided into three groups of 10 according to their E scores, their pain tolerance decreases from 17.2 (high E) through 9.3 to 5.6 (low E); 'We are indebted to the Society for Research in Human Ecology for a grant which made this study possible.

Review of Current Research in Demography and Human Ecology

Review of Current Research in Demography and Human Ecology