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PubMed1983

Hostility reduction in married and unacquainted couples.

Fifty-two persons (26 married couples) competed in a complex reaction time task and set durations of 100 db noise for either their respective spouses or an opposite sex stranger. Each S's punitive settings were countered by four presequenced counteraggression strategies. Wives were responsive to a broader range of aggression reduction strategies than were husbands. Results suggest that minimum retaliation is most consistently effective across sex and may be a behavior skill necessary to avoid escalation of aggression and to keep communication channels open.

Adult↗
PubMed2004

Novel analogs of the sigma receptor ligand BD1008 attenuate cocaine-induced toxicity in mice.

Previous studies have shown that BD1008 (N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(1-pyrrolidinyl)ethylamine) and related analogs attenuate the toxicity and stimulant effects of cocaine through antagonism of sigma receptors. In the present study, six analogs of BD1008 (UMB 98-103) were synthesized and evaluated in receptor binding and behavioral studies. Competition binding studies confirmed that all six compounds have high affinity for sigma1 receptors, moderate affinity for sigma2 receptors, and low to negligible affinity for monoamine transporters, opioid, N-methyl-D-aspartate, dopamine, and 5-HT receptors. In behavioral pharmacological studies, pretreatment of mice with UMB 100, UMB 101, or UMB 103 significantly attenuated cocaine-induced convulsions and lethality. Together with earlier studies, the data suggest that analogs of BD1008 are promising medication development leads for reducing the toxicity of cocaine.

Animals↗
PubMed2005

Maternal experience produces long-lasting behavioral modifications in the rat.

From 5 to 22 months of age, cognitive and emotional responses of nulliparous, primiparous, and multiparous rats were assessed using a dry land maze (DLM) and an elevated plus-maze (EPM) at 4-month intervals. Parous rats exhibited improved spatial memory in the probe and competitive versions of the DLM, and more exploration in the EPM and a novel stimulus test relative to nulliparous females. The nulliparous females, however, outperformed parous rats during the DLM visual cue test at 17 months of age. At 23 months, no differences in stressed corticosterone levels or Golgi-stained hippocampal neurons were observed. Thus, cognitive and emotional modifications were observed in parous rats; the neurobiological mechanisms for these enduring effects, however, remain to be identified.

Age Factors↗
PubMed2000

Effects of the competitive nicotinic antagonist erysodine on behavior occasioned or maintained by nicotine: comparison with mecamylamine.

RATIONALE: The cellular effects of nicotine underlying its addictive liability are thought to be mediated by neuronal nicotinic receptors (nACHRs) in the central nervous system. It is believed that densely expressed beta32-containing nACHRs in the central nervous system are responsible for these actions, but few data are available that can directly assess subtype mediation of nicotine's acute subjective and reinforcing effects. OBJECTIVE: The present study compared the effects of the competitive nACHR antagonist erysodine and the noncompetitive antagonist mecamylamine in rats trained to discriminate or self-administer nicotine. METHODS: Adult male rats were trained to discriminate 0.4-mg/kg injections of nicotine from vehicle in a two-lever procedure of food-maintained behavior, or to self-administer 0.03-mg/kg injections of nicotine under fixed-ratio 5 or progressive-ratio schedules of reinforcement. Additional rats were trained under a food-maintained procedure of lever pressing. RESULTS: Erysodine (0.3-10 mg/kg) and mecamylamine (0.1-1.0 mg/kg) blocked nicotine discrimination, although only erysodine produced the rightward shift that would be predicted of a competitive antagonist. Erysodine (0.32-32 mg/kg) and mecamylamine (0.32-3.2 mg/kg) also selectively reduced nicotine self-administration on a fixed-ratio schedule and lowered break points on a progressive-ratio schedule. CONCLUSIONS: Based on the known affinity of erysodine for alpha4beta2 nACHRs and its selectivity relative to alpha7 and alpha1beta1gammadelta receptors, the present data support a critical role of beta2-containing nACHR constructs in the discriminative and reinforcing actions of nicotine.

Animals↗
PubMed2001

Social games in a social network.

We study an evolutionary version of the Prisoner's Dilemma game, played by agents placed in a small-world network. Agents are able to change their strategy, imitating that of the most successful neighbor. We observe that different topologies, ranging from regular lattices to random graphs, produce a variety of emergent behaviors. This is a contribution towards the study of social phenomena and transitions governed by the topology of the community.

Competitive Behavior↗
PubMed1976

Sex cues in estimating and performing a simple motor task.

The present study examined direct behavioral effects of sex cues in a modified level of aspiration experiment for 60 male and 60 female undergraduates. Each S was provided a constant referent score (25), identified as the average score, average score for men, or average score for women. E's sex was controlled and its effects examined. Male Ss estimated and performed significantly higher than female Ss. All Ss provided the average score for the men estimated and performed lower than Ss provided the average score for women. Effect of E's sex was nonsignificant. Results were discussed in terms of behavioral effects of sex-role stereotypes and the implications of such effects for future research.

Aspirations, Psychological↗
PubMed2003

The effect of health plan characteristics on Medicare+ Choice enrollment.

OBJECTIVE: To provide national estimates of the effect of out-of-pocket premiums and benefits on Medicare beneficiaries' choice among managed care health plans. DATA SOURCES/STUDY SETTING: The data represent the population of all Medicare+ Choice (M+C) plans offered to Medicare beneficiaries in the United States in 1999. STUDY DESIGN: The dependent variable is the log of the ratio of the market share of the jth health plan to the lowest cost plan in the beneficiary's county of residence. The explanatory variables are measures of premiums and benefits in the jth health plan relative to the premiums and benefits in the lowest cost plan. DATA COLLECTION METHODS: The data are from the 1999 Medicare Compare database, and M+C enrollment data from the Centers for Medicare and Medicaid Services (CMS). PRINCIPAL FINDINGS: A $10 increase in an M+C plan's out-of-pocket premium, relative to its competitors, is associated with a decrease of four percentage points in the jth plan's market share (i.e., from 25 to 21 percent), holding the premiums of competing plans constant. CONCLUSIONS: Although our price elasticity estimates are low, the market share losses associated with small changes in a health plan's premium, relative to its competitors, may be sufficient to discipline premiums in a competitive market. Bidding behavior by plans in the Medicare Competitive Pricing Demonstration supports this conclusion.

Aged↗
PubMed2005

Noninteracting versus interacting poly(N-isopropylacrylamide)-surfactant mixtures at the air-water interface.

Two polymer-surfactant mixtures have been studied at the air-water interface using neutron reflectivity and surface tension techniques. For the noninteracting system poly(N-isopropylacrylamide) (PNIPAM)/octaethyleneglycol mono n-decyl ether (C10E8), the adsorption behavior is competitive and driven purely by surface pressure (pi). When pi(polymer) > pi(surfactant), the surface layer consists of almost pure polymer, and for pi(polymer) < pi(surfactant), the polymer is displaced from the surface by the increasing pressure of the surfactant. Beyond the CMC, the polymer is completely displaced from the surface. For the interacting system PNIPAM/sodium dodecyl sulfate (SDS) where the two species interact strongly in the bulk beyond the critical aggregation concentration (CAC), the surface behavior is more original. Earlier neutron reflectivity studies investigated PNIPAM adsorption behavior where the SDS was contrast-matched to the solvent. In the present study, complementary measurements of SDS adsorption where PNIPAM is contrast-matched to the solvent give a complete view of the surface composition of the mixed system. At a constant polymer concentration, with increasing SDS, three main regimes are obtained. For C(SDS) < CAC, adsorption is governed by simple competition and PNIPAM is predominant at the interface. At intermediate SDS concentration (CAC < C(SDS) < x2, where x2 indicates the predominance of free SDS micelles), interfacial behavior is governed by bulk polymer-surfactant interaction. Adsorbed polymer is displaced from the interface to form PNIPAM-SDS complex in the bulk. SDS adsorption remains weak since most of the SDS molecules are used to form bulk polymer-surfactant aggregates. Further increase in SDS concentration results in continued displacement of PNIPAM and an abrupt increase in SDS adsorption. This is a result of saturation of bulk polymer chain with adsorbed micelles. Interestingly, beyond x2, PNIPAM is not completely displaced from the surface. A mixed PNIPAM-SDS adsorbed layer with enhanced packing of the SDS monolayer is formed.

Acrylic Resins↗
PubMed1989

Cardiovascular correlates of type A behavior components during social interaction.

This study examined the cardiovascular (CV) correlates of the primary Type A behavior components during social interactions. Brief dialogues were created to role-play (RP) stereotypic Type A and Type B ways of responding to three common social situations designed to elicit hostility (H), time-urgency (T), and competition (C). Situations and dialogues were validated by independent raters. Thirty undergraduate students were identified as Type A and 30 as Type B, with 15 males and 15 females in each group. Subjects were provided scripts for each of the six experimental RPs and rehearsed them prior to the CV assessment. Measures of systolic and diastolic blood pressure (SBP, DBP) and heart-rate (HR) were obtained during an adaptation period and during each RP. Analyses of the "A" (i.e. H, T, C) versus "B" (i.e. non-H, non-T, non-C) RPs indicated that DBP (p less than 0.03) and HR (p less than 0.002) were higher during the H as compared with non-H RP. Significantly higher SBP was observed in the T as compared with the non-T RP (p less than 0.04). No CV differences were observed in the comparison of the C and non-C RPs. Analyses comparing the three "Type A" RPs revealed higher SBP during H and T RPs, as compared with the C RP (p less than 0.003). Effects of subject Type (i.e. A/B) were not obtained in any analysis. These findings indicate that hostile and time-urgent social interactions are associated with significant increases in CV arousal which are independent of overall Type status.

Adult↗
PubMed2004

Testosterone reduces responsiveness to nociceptive stimuli in a wild bird.

The hormone testosterone (T) is involved in the control of aggressive behavior in male vertebrates. T enhances the frequency and intensity of aggressive behaviors during competitive interactions among males. By promoting high-intensity aggression, T also increases the risk of injury and presumably the perception of painful stimuli. However, perception of painful stimuli during fights could counteract the expression of further aggressive behavior. We therefore hypothesize that one function of T during aggressive interactions is to reduce nociception (pain sensitivity). Here, we experimentally document that T indeed reduces behavioral responsiveness to a thermal painful stimulus in captive male house sparrows (Passer domesticus). Skin nociception was quantified by foot immersion into a hot water bath, a benign thermal stimulus. Males treated with exogenous testosterone left their foot longer in hot water than control birds. Conversely, males in which the physiological actions of testosterone were pharmacologically blocked withdrew their foot faster than control birds. Testosterone might exert its effects on pain sensitivity through conversion into estradiol in the dorsal horn of the spinal cord. Decreased nociception during aggressive encounters may promote the immediate and future willingness of males to engage in high-intensity fights.

Aggression↗
PubMed2003

The social risk hypothesis of depressed mood: evolutionary, psychosocial, and neurobiological perspectives.

The authors hypothesize that depressed states evolved to minimize risk in social interactions in which individuals perceive that the ratio of their social value to others, and their social burden on others, is at a critically low level. When this ratio reaches a point where social value and social burden are approaching equivalence, the individual is in danger of exclusion from social contexts that, over the course of evolution, have been critical to fitness. Many features of depressed states can be understood in relation to mechanisms that reduce social risk in such circumstances, including (a) hyper-sensitivity to signals of social threat from others, (b) sending signals to others that reduce social risks, and (c) inhibiting risk-seeking (e.g., confident, acquisitive) behaviors. These features are discussed in terms of psychosocial and neurobiological research on depressive phenomena.

Affect↗
PubMed2001

Evaluation of the offensive behavior of elite soccer teams.

The purpose of the present study was to evaluate the offensive behavior of the four elite teams (France, Brazil, Croatia, and Holland) using data from the semifinals of the 18th World Soccer Championship in France in 1998. 28 videotaped soccer games were observed, 7 for each team. The protocol contained the following parameters of evaluation: (a) successful pass in the defensive and middle area, (b) unsuccessful pass in the defensive and middle area, (c) attempt on goal in the offensive area, and (d) cross and follow-up action. A multivariate analysis of variance showed the teams' plan was significantly different only in playing the ball back to the goalkeeper. This last action, used more often by Holland than by the other teams, indicated its restrained offensive behavior, which may be one of the reasons for its defeat in some games.

Adult↗
PubMed2006

Plant population growth and competition in a light gradient: a mathematical model of canopy partitioning.

Can a difference in the heights at which plants place their leaves, a pattern we call canopy partitioning, make it possible for two competing plant species to coexist? To find out, we examine a model of clonal plants living in a nonseasonal environment that relates the dynamical behavior and competitive abilities of plant populations to the structural and functional features of the plants that form them. This examination emphasizes whole plant performance in the vertical light gradient caused by self-shading. This first of three related papers formulates a prototype single species Canopy Structure Model from biological first principles and shows how all plant properties work together to determine population persistence and equilibrium abundance. Population persistence is favored, and equilibrium abundance is increased, by high irradiance, high maximum photosynthesis rate, rapid saturation of the photosynthetic response to increased irradiance, low tissue respiration rate, small amounts of stem and root tissue necessary to support the needs of leaves, and low density of leaf, stem, and root tissues. In particular, equilibrium abundance decreases as mean leaf height increases because of the increased cost of manufacturing and maintaining stem tissue. All conclusions arise from this formulation by straightforward analysis. The argument concludes by stating this formulation's straightforward extension, called a Canopy Partitioning Model, to two competing species.

Ecosystem↗
PubMed1994

Interrelation between stress and coaches' behavior during rest periods.

The purpose of the present investigation was to examine the interrelation between stress and coaches' behavior during rest periods. Subjects were 154 German coaches who completed the Rest Period Questionnaire and a Bibliographic Questionnaire for Coaches designed to attribute stress to coaches' behavior during rest periods. Analysis indicated that coaches who are highly stressed by the practice rate themselves significantly less active and less authoritarian during rest periods than do their low stressed colleagues. In addition, coaches who are highly stressed by the competition rate themselves significantly less warm-hearted than the low stressed group.

Adult↗
PubMed1983

Type A behavior: an ecological approach.

The recognized association between Type A behavior and coronary heart disease has prompted efforts to alter the behavior's deleterious components in both individuals who have experienced myocardial infarction and those who are at risk for that disease. Utilizing concepts from psychology, sociology, history, and other disciplines and material from scholarly and popular literature, this paper suggests that instead of singularly concentrating on components at the level of the individual, it is important to view Type A behavior from an ecological perspective, with attention directed at the interpersonal, institutional, and cultural environments of individuals. This perspective will enhance understanding of Type A behavior and possibly stimulate interventions at the primary as well as secondary and tertiary prevention levels.

Achievement↗
PubMed2004

Ethics and the athlete: why sports are more than a game but less than a war.

Are the ethics of athletes complex? Consider that an elite bicyclist might inject himself with hormones to increase his exercise capacity,but if his opponent falls, then that same hormone-abusing athlete will likely stop until his opponent has regained control. This article reviews key concepts from the philosophy of sport. Using six cases from the sports archives, it presents a practical framework for interpreting and assessing the moral status of an athlete's behavior. This work enables readers to appreciate more clearly both the contextual subtleties and the robust relationship between ethics and the athlete.

Bicycling↗