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PubMed1983

Component analysis of the type A coronary-prone behavior pattern in male and female college students.

Two studies investigated the psychological dimensions encompassed by the Rosenman Structured Interview (SI) method of assessing the Type A behavior pattern. In Study 1, female students completed the SI and Jenkins Activity Survey (JAS). Factor analysis of the verbal stylistic and answer content components of the SI yielded a 5-factor solution, with one factor--Clinical Rating--accounting for most nonerror variance in Type A ratings. The remaining factors were derived from answer content and correlated more substantially with JAS Type A ratings than with SI Type A ratings. In Study 2, male and female college students completed the SI and JAS and a battery of questionnaires that tap trait dimensions implied by the conceptual definition of Type A. For both males and females, SI ratings of Type A could almost be completely predicted by scores on the Clinical Rating factor. For both sexes, content dimensions of the SI related to other measures of Type A and to Type A-consistent traits, whereas the Clinical Rating factor was only modestly associated with such traits. Moreover, sex differences were observed in the trait constellations composing SI and JAS definitions of Type A. These results suggest that a discrepancy exists between conceptual and operational definitions of the Type A pattern.

Adolescent↗
PubMed2004

Adaptive evolution of social traits: origin, trajectories, and correlations of altruism and mobility.

Social behavior involves "staying and helping," two individual attributes that vary considerably among organisms. Investigating the ultimate causes of such variation, this study integrates previously separate lines of research by analyzing the joint evolution of altruism and mobility. We unfold the network of selective pressures and derive how these depend on physiological costs, eco-evolutionary feedbacks, and a complex interaction between the evolving traits. Our analysis highlights habitat saturation, both around individuals (local aggregation) and around unoccupied space (local contention), as the key mediator of altruism and mobility evolution. Once altruism and mobility are allowed to evolve jointly, three general insights emerge. First, the cost of mobility affects the origin of altruism, determining whether and how quickly selfishness is overcome. Second, the cost of altruism determines which of two qualitatively different routes to sociality are taken: an evolutionary reduction of mobility, resulting in higher habitat saturation, is either preceded or followed by the adaptive rise of altruism. Third, contrary to conventional expectations, a positive correlation between evolutionarily stable levels of altruism and mobility can arise; this is expected when comparing populations that evolved under different constraints on mobility or that differ in other life-history traits.

Adaptation, Physiological↗
PubMed1984

A quantitative genetic model of two-policy games between relatives.

Equations are derived for the change per generation of the population mean of the probability that an individual adopts a policy 1 as opposed to a policy 2 in a behavioral interaction between two diploid individuals of the same generation in which two policies are possible. The probability is assumed to be a quantitative genetic trait determined by many additively acting genes of small effects and an independent environmental component. Equations are derived for the case that interactions occur at random between all members of the population and also for the case that interactions occur between relatives of the same average degree of relatedness. It is assumed that each group of relatives and the number of such groups is sufficiently large. For a quantitative genetic trait with the additional assumption of unlinked loci the latter equation can be heuristically derived from the first by substituting the corresponding inclusive fitness effects. When per locus selection coefficients are small and linkage equilibrium holds, the average degree of relatedness can be equated approximately with Wright's coefficient of relationship. Thus, the quantitative genetic model provides a genetic basis for the inclusive fitness approach toward games between relatives. By contrast, in a monogenic system with major gene effects we obtain substantially different results which contradict those obtained by the inclusive fitness approach in game theory. Applications are made to the hawk-dove game, and the simple and iterated forms of the prisoner's dilemma.

Altruism↗
PubMed2006

Data withholding in genetics and the other life sciences: prevalences and predictors.

PURPOSE: To better understand the variety and prevalence of data withholding in genetics and the other life sciences and to explore factors associated with these behaviors. METHOD: In 2000, a sample of 2,893 geneticists and other life scientists (OLS) at the 100 most research-intensive universities in the United States were surveyed concerning data withholding and sharing. The instrument was developed and pretested in 1999. The two primary outcome measures were withholding in verbal exchanges with colleagues about unpublished research (verbal withholding) and withholding as part of the publishing process (publishing withholding). The independent variables related to the personal characteristics, research characteristics of faculty, and previous experience with data withholding. RESULTS: A total of 1,849 faculty responded (64%): 1,240 geneticists and 600 OLS. Forty-four percent of geneticists and 32% of OLS reported participating in any one of 13 forms of data withholding in the three previous years. Publishing withholding (geneticists 35%, OLS 25%) was more frequent than verbal withholding (geneticists 23%, OLS 12%). In multivariate analyses, male gender, participation in relationships with industry, mentors' discouraging data sharing, receipt of formal instruction in data sharing, and negative past experience with sharing were significantly associated with either verbal or publishing withholding among either geneticists or OLS. CONCLUSIONS: Data withholding is common in biomedical science, takes multiple forms, is influenced by a variety of characteristics of investigators and their training, and varies by field of science. Encouraging openness during the formative experiences of young investigators may be critical to increased data sharing, but the effects of formal training do not appear straightforward.

Access to Information↗
PubMed1985

Medical psychology in exercise and sport.

Several psychological outcomes that accompany acute and chronic exercise have medical significance. Transient reductions in somatic tension and subjective anxiety appear most reliable. Symptom abatement in moderate depression can occur with chronic exercise in a manner comparable to psychotherapy and may offer a better prognosis in some instances. Other cognitive, behavioral, and perceptual events associated with exercise may assist in managing mental health, and exercise has been successfully used as a therapeutic adjunct in a variety of psychiatric disorders. Regular exercise may also complement treatments designed to manage aspects of coronary-prone behavior and psychoendocrine responsivity to mental stress. The lack of strict experimental control or effective placebo contrasts in most exercise studies precludes a convincing argument that exercise causes the psychological outcomes observed. Rather, expectancy of benefits, generalized treatment or attention effects, social reinforcement, and past history or selection bias represent likely alternatives. These competing explanations do not discount, however, that many individuals benefit in a clinically significant way. Exercise offers a low-cost alternative or adjunct with side effects that appear largely health-related. Although the effective psychological dosage or modality has not been quantified, current physiologic guidelines of the American College of Sports Medicine (large muscle rhythmic activity, for 20 to 60 minutes, 3 to 5 days per week at 60 to 80 per cent age-adjusted maximal heart rate), or a weekly caloric cost of 2000 kcal, should be effective with little medical risk. However, no evidence confirms that an increase in metabolic or psychoendocrine tolerance to exercise is necessary or sufficient for psychological outcomes to occur. Although biologic adaptations are known to follow exercise training and subside with diminished activity, there is currently no objective evidence that habitual exercise leads to dependence. If exercise has use in managing subjective or somatic symptoms, these may return during periods of exercise abstinence. Moreover, despite popular hypotheses concerning endorphins and biogenic amines, no direct relationships have yet been shown between exercise-induced mood swings and peripheral biochemical events. A proportion of habitual runners have reported acute episodes of euphoria-like states during or following exercise, but this remains a subjective and unpredictable event that may be related to psychophysiologic relaxation or acute changes in self-esteem.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed2002

Multitrophic interactions of the silverleaf whitefly, host plants, competing herbivores, and phytopathogens.

Our laboratory found that silverleaf whitefly (SLW; Bemisia argentifolii Bellows & Perring) feeding alters host plant physiology and chemistry. The SLW induces a number of host plant defenses, including pathogenesis-related (PR) protein accumulation (e.g., chitinases, beta-1,3-glucanases, peroxidases, chitosanases, etc.). Induction of the PR proteins by SLW feeding occurs in various plant species and varieties. The extent and type of induction is dependent on a number of factors that include host plant growing conditions, the length of time the host plant is exposed to SLW feeding, the plant variety, and SLW population densities. The appearance of PR proteins correlates well with reduced infestations of conspecific insect herbivore competitors. Greenhouse and field experiments in which herbivore competitors (cabbage looper, Trichoplusia ni; leaf miner, Liromyza trifolii) were placed on plants previously exposed to SLW feeding demonstrated behavioral differences (oviposition, feeding preferences) and reduced survival rates and development times of these insects. The interaction was asymmetrical, i.e., SLW infestations of plants previously exposed to leaf miners had little or no effect on SLW behavior (oviposition). Induction of plant-defensive proteins by SLW feeding was both local (at the feeding site) and systemic (uninfested leaves distant to the feeding site). There are interactions between diseases such as tomato mottle virus (ToMoV; a geminivirus) and the host plant and SLW. PR proteins were induced in tomato plants infected with ToMoV much as they were via non-viruliferous SLW feeding. The presence of ToMoV in tomato plants significantly increased the number of eggs produced by SLW females. Experiments using tomato plants, powdery mildew (PM), and tobacco mosaic virus (TMV) show that whitefly infestations can affect plant pathogen relationships but the effects vary among pathogen types. Enzyme analyses prior to pathogen inoculation showed that whitefly treatment significantly increased the activities of foliar chitinase and peroxidase. Evaluation of pathogen growth 3 weeks after inoculation showed that whitefly feeding significantly reduced the incidence of PM. However, TMV levels evaluated by ELISA were not significantly affected by whitefly feeding. Six weeks after inoculation with pathogens, the chitinase and peroxidase activities were still elevated in plants initially fed on by whiteflies but continuing pathogen infection had no effect on these enzymes. The possibility that geminivirus infection and/or SLW infestations isolate the host plant for the selected reproduction of the virus and the insect is discussed. Multitrophic cascade effects may contribute to the successful eruptive appearance of SLW on various crops, ranking them as a major pest. They may explain the general observation that when SLW infest a host plant there are few if any competing insect herbivores and pathogens found in the host. However, the results indicate that certain SLW-virus relationships could be mutualistic.

Animals↗
PubMed2000

Social effects and boar taint: significance for production of slaughter boars (Sus scrofa).

A study was conducted to elucidate the effects of social factors on the concentrations of boar taint substances, androstenone and skatole, in boars. The factors included dominance (social rank) and the effects of strongly tainted animals on other members of the group. Four successive replicates of 100 pigs (50 boars + 50 gilts) with an average live weight of 24 kg were randomly allocated to 10 pens of 10. Data for this study were collected during the period of 67 to 114 kg of live weight and included the repetitive recording of agonistic behavior during competitive feeding; blood sampling for determination of plasma androstenone, skatole and testosterone in boars; feces sampling for determination of skatole content; and collection of bulbourethral glands in boars, and uteri plus ovaries in gilts at slaughter, for the assessment of sexual maturity. Results show an influence of social rank on plasma concentrations of androstenone (P = .0001) and testosterone (P = .0001), the weight of the bulbourethral glands (P = .0001), and plasma skatole (P = .02). Pens were classified according to the pig with the highest concentration of androstenone in the pen into high, medium, and low maximum pens. In pens with high maximum concentrations of androstenone, the second-highest androstenone concentration (P = .0001), and the average concentration (P = .0003) in the pen were higher than those in pens with medium or low maximum concentrations of androstenone. Mean aggression level was also higher (P = .02), but pens with high maximum aggression level did not have higher mean androstenone concentration. Rank effect on androstenone was more important than aggression effect. Neither maximum androstenone concentration nor maximum aggression level in a pen was related to the pen mean stage of sexual maturity in either sex. No influences of rank, aggression, or aggression received were found on the feces skatole level, and no pheromonal communicative function was demonstrated for skatole. High androstenone concentrations did not have a suppressive effect on androstenone concentrations in other males of the group; on the contrary, the levels were increased. This may be due to a stimulating effect of androstenone and, possibly, mating activity. Consequently, in the production of boars for slaughter, strongly tainted animals should be avoided or removed and mating activity minimized. This could be facilitated by, for instance, slaughtering before sexual maturity or separate rearing of the sexes.

Abattoirs↗
PubMed2003

Cognitive behavioral stress management effects on injury and illness among competitive athletes: a randomized clinical trial.

Cognitive behavioral stress management (CBSM) has previously been found to reduce fatigue, depression, and cortisol response to heavy exercise training among competitive collegiate athletes and to speed physical and psychological recovery from surgery. Our study assessed the efficacy of a CBSM program to reduce the frequency of injury and illness among collegiate athletes in a randomized, single-blind, controlled clinical trial. Following assessment of baseline medical history, mood state, stress, cortisol, sleep, alcohol use, and exercise training, collegiate rowers were stratified by gender and competitive level and randomly assigned to either a control group or a CBSM group. Exercise training information and psychosocial assessments were repeated immediately following the intervention period, and health care providers who were blinded to participant assignment recorded the frequency of medical visits and the number of days injured or ill until the end of the season. Athletes randomly assigned to a CBSM group experienced significant reductions in the number of illness and injury days as compared to control group athletes. CBSM participants also had half the number of health service visits as did controls. The data suggest that a time-limited CBSM intervention designed specifically for an athlete population may be an effective prophylactic treatment to reduce the incidence of injury and illness among competitive collegiate athletes.

Adolescent↗
PubMed1978

Medical care of the athlete.

Atheletics involve many health hazards for children. The possibility for injury is present and participation means a calculated risk. To justify the risks, the benefits must outweigh the dangers. Sports, suitably engaged in, promote both physical and mental health. As pediatricians we become involved on two occasions: during the preseason examination to determine the child's fitness to participate, and when injury has occurred. Adequate examining means an understanding of what is involved to participate, promoting safety standards, and equitable competitive situations.

Athletic Injuries↗
PubMed2003

Psychosocial factors and risk of hypertension: the Coronary Artery Risk Development in Young Adults (CARDIA) study.

CONTEXT: Although psychosocial factors are correlated, previous studies on risk factors for hypertension have typically examined psychosocial factors individually and have yielded inconsistent findings. OBJECTIVE: To examine the role of psychosocial factors of time urgency/impatience (TUI), achievement striving/competitiveness (ASC), hostility, depression, and anxiety on long-term risk of hypertension. DESIGN, SETTING, AND STUDY POPULATION: A population-based, prospective, observational study using participant data from the Coronary Artery Risk Development in Young Adults (CARDIA) study. A total of 3308 black and white adults aged 18 to 30 years (when recruited in 1985 and 1986) from 4 US metropolitan areas and followed up through 2000 to 2001. MAIN OUTCOME MEASURES: Fifteen-year cumulative incidence of hypertension (systolic blood pressure of 140 mm Hg or higher, diastolic blood pressure of 90 mm Hg or higher, or taking antihypertensive medication). RESULTS: The incidence of hypertension at year 15 was 15% from baseline and 13.6% from year 5. After adjusting for the same set of hypertension risk factors and each of the psychosocial factors of TUI, ASC, hostility, depression, and anxiety in 5 separate logistic regression models, higher TUI and hostility were significantly associated with risk of developing hypertension at 15-year follow-up for the total sample. Compared with the lowest score group, the adjusted odds ratio (OR) for TUI was 1.51 (95% confidence interval [CI], 1.12-2.03) for a score of 1; 1.47 (95% CI, 1.08-2.02) for a score of 2; and 1.84 (95% CI, 1.29-2.62) for a score of 3 to 4 (P for trend =.001). Compared with the lowest quartile group, the adjusted OR for hostility was 1.06 (95% CI, 0.76-1.47) for quartile 2; 1.38 (95% CI, 1.00-1.91) for quartile 3; and 1.84 (95% CI, 1.33-2.54) for quartile 4 (P for trend <.001). No consistent patterns were found for ASC, depression, or anxiety. Race- and sex-specific analyses and multivariable models with simultaneous adjustment for all 5 psychosocial factors and other hypertension risk factors had generally similar results. CONCLUSION: Among young adults, TUI and hostility were associated with a dose-response increase in the long-term risk of hypertension.

Adult↗
PubMed1998

Correlated response, competition, and female canine size in primates.

Recently, comparative analyses of female canine tooth size in primates have yielded two hypotheses to explain interspecific variation in female relative canine size. Greenfield ([1992] Int. J. Primatol. 13:631-657; [1992] Yrbk. Phys. Anthropol. 35:153-184; [1996] J. Hum. Evol. 31:1-19) suggested that covariation in male and female canine size across species indicates that female canine size reflects correlated response (in which the expression of a trait in one sex causes the expression of the same trait in the other sex). Plavcan et al. ([1995] J. Hum. Evol. 28:245-276) noted that female canine size in primates is associated with variation in categorical estimates of the intensity of female-female agonistic competition, suggesting that selection favors large female canine size in many species. While it may seem that the two models are in conflict, they are not. To simultaneously evaluate these two models, this analysis examines the joint relations between male canine size, female canine size, and estimates of female-female competition in a sample of 108 primate species. Overall, female canine size is correlated with variation in male canine size. Controlling for variation in male canine size, female canine size is also correlated with estimates of the intensity of female-female agonistic competition. The relation between these variables differs strongly between anthropoid and strepsirhine primates. In anthropoids, the data suggest that selection for the development of large canines in females is not constrained by any affect of correlated response. In strepsirhines, the evidence suggests that sexual selection may affect male canine size but that correlated response affects female canine size, resulting in monomorphism for most species. These observations help reconcile the observations of Greenfield ([1992] Int. J. Primatol. 13:631-657; [1996] J. Hum. Evol. 31:1-19) and Plavcan et al. ([1995] J. Hum. Evol. 28:245-276) and provide a more precise model for understanding interspecific variation in female canine size and hence canine dimorphism.

Animals↗
PubMed1998

Sex-specific usage patterns of sleeping sites in grey mouse lemurs (Microcebus murinus) in northwestern Madagascar.

Sleeping sites are a potentially important resource for grey mouse lemurs since they are confronted with high daily temperature fluctuations and a high predation pressure. In order to determine the existence and degree of resource competition, sleeping site characteristics, locations, and usage patterns as well as sleeping group compositions were investigated in a 3 month field study in a dry deciduous forest of northwestern Madagascar. The daily sleeping sites of females were on average better insulated and safer than those of males. Males used more sleeping sites and changed the site more often than females. During the whole study, males slept alone, whereas the females formed stable sleeping groups in on average 83.7% of the days. Sex-specific differences in usage patterns might be explained by intersexual resource competition and female dominance and could possibly be related to differential parental investment of the sexes. The underlying study indicates that sleeping sites may be a restricted and defendable resource for grey mouse lemurs. The investigation gives new insights into the distribution patterns and social organization of this species.

Animals↗
PubMed1986

Androgen receptor in human normal and malignant pancreatic tissue and cell lines.

Estrogen and progestogen receptors have been demonstrated in human pancreatic adenocarcinoma tissue. Tumor growth as xenografts in nude mice is promoted by testosterone and retarded by cyproterone acetate but is not influenced by estrogens, progestogens, or their antagonists, although estrogen receptors were demonstrated in xenograft cytosol. A new sensitive microassay technique for sex steroid receptors which relies on affinity chromatography was used in this study. With this assay, androgen receptors were detected in five fresh human pancreatic adenocarcinoma specimens (three male), two pancreatic cancer cell lines (Mia PaCa 2 and Ger), one xenograft tumor which responded to androgens, five specimens of normal adult pancreas (two male), and a pool of fetal pancreatic tissue. The similarity of the androgen receptor in pancreatic carcinoma to that of classical androgen target organs was demonstrated by sedimentation behavior and competitive binding studies. The improved sensitivity of the microassay allowed low levels of estrogen, androgen, and progesterone receptors to be detected in normal adult pancreatic tissue.

Adenocarcinoma↗
PubMed1977

Schizophrenic performance during interpersonal competitive conditions.

Two equivalent forms of four standardized tests were administered to 41 schizophrenics, 36 patients with personality disorder diagnoses, and 36 employees at the Wyoming State Hospital. Each diagnostic group was divided into experimental and control groups; the experimental Ss from each diagnostic group took the second form of each test under paired, competitive conditions. The competitive conditions did not affect the experimental Ss' performance on any of the four tests to an acceptably significant level, although the experimental Ss from each diagnostic group performed better on a visual-motor task at a borderline level of significance. The results of the research are interpreted as supporting previous competition research that showed competitive conditions to be highly task-specific. The results do not support the numerous theories and some research studies that suggest that competitive conditions impair schizophrenic functioning.

Adult↗