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PubMed1998

Psychometric properties of the social-conflict scales for Chinese adolescents.

Despite the gradual increase of research on social conflicts, psychometric characteristics of social-conflict scales have not been extensively examined, especially in the adolescent population. In this study, the internal consistency, test-retest reliability, and criterion-related validity of 2 established social-conflict scales were examined in a sample of 581 Chinese adolescents. There were high internal consistencies and test-retest reliabilities for both the Family Conflict Scale and the Friend Conflict Scale. The scales were significantly related to appraisals of the quality of social relations, psychological distress, and trait anxiety.

Adolescent↗
PubMedDate not supplied

Effect of carbamazepine on dopamine release and reuptake in rat striatal slices.

Carbamazepine has been shown to enhance dopaminergic agonist behavioral effects, but not to displace [3H]spiroperidol binding. To verify if carbamazepine acts presynaptically on dopaminergic neurons, reuptake and release of [3H]dopamine were measured in rat striatal slices in vitro. It was observed that carbamazepine blocked 20% of the reuptake of [3H]dopamine, while cocaine blocked 82% of the reuptake, compared with control. Carbamazepine released 62% and tyramine released 92% of the accumulated [3H]dopamine, compared with control. It was concluded that carbamazepine acts presynaptically on striatal neurons, mainly through enhancement of dopamine release. This finding can be related to some behavioral effects described for carbamazepine; however, the importance of its effects in epileptic and manic-depressive patients remains to be clarified.

Animals↗
PubMed1998

Elevation of brain 5-HT activity, POMC expression, and plasma cortisol in socially subordinate rainbow trout.

Agonistic behavior, brain concentrations of serotonin (5-hydroxytryptamine, 5-HT), and 5-hydroxyindoleacetic acid (5-HIAA, the main 5-HT metabolite), plasma cortisol levels, and the pituitary expression of pro-opiomelanocortin (POMC) A and B mRNA were determined in socially dominant and subordinate rainbow trout after 1 or 7 days of social interaction. Telencephalic and brain stem 5-HIAA/5-HT ratios, plasma cortisol levels, and pituitary POMC mRNA concentrations were elevated in fish being subordinate for 1 day. Furthermore, neither telencephalic 5-HIAA/5-HT ratios nor pituitary POMC A or POMC B mRNA expression showed any decline after 7 days of social interaction. By contrast, plasma cortisol concentrations of subordinate fish declined after 7 days but were still significantly higher than in dominant fish. Furthermore, in subordinate fish, hypothalamic 5-HIAA/5-HT ratios and plasma cortisol levels were highly correlated, suggesting an important role of hypothalamic 5-HT in the regulation of the teleost hypothalamic-pituitary-interrenal (HPI) axis. The number of aggressive acts received and plasma cortisol levels were highly correlated in 1-day subordinates, a relationship not seen in fish subjected to 1 wk of subordination. Thus the chronic stress experienced by subordinates in established dominance hierarchies appears to be more closely related to the threat imposed by the presence of the dominant fish than to actual aggressive encounters. The sustained elevation of pituitary POMC mRNA expression, an effect mainly related to an increase of melanotropic POMC expression, in subordinates could be a mechanism serving to maintain HPI axis excitability and promote acclimation in these individuals.

Animals↗
PubMed1976

Effect of parturition and group composition on competitive drinking order in stumptail macaques (Macaca arctoides).

Competitions for access to water were conducted weekly in a captive group of Macaca arctoides. After giving birth, parturient females that had been low in order of access showed elevation. Elevation was not due solely to increased motivation for water, since it depended on the presence of higher ranking animals. Presence of higher ranking animals did not influence agonistic behavior involving parturient females as greatly as it influenced order of access to water. Elevation of access order after parturition tended to be long lasting, and it was not an artifact of depression in access order preceding birth. Delivery of a dead fetus did not alter access order.

Animals↗
PubMedDate not supplied

The soleus muscle acts as an agonist for the anterior cruciate ligament. An in vitro experimental study.

BACKGROUND: Although the quadriceps muscles are known antagonists for the anterior cruciate ligament and the hamstring muscles are known agonists, the influence of the calf muscles on knee stability is not well understood. HYPOTHESIS: The soleus muscle acts as an anterior cruciate ligament agonist and the gastrocnemius muscle acts as an anterior cruciate ligament antagonist. STUDY DESIGN: Controlled laboratory study. METHODS: Six cadaveric knees were tested with individual and combined activation of the gastrocnemius and soleus muscles to determine the influence of simulated muscle contraction on tibiofemoral motion. RESULTS: At all flexion angles, applying the soleus muscle force tended to translate the tibia posteriorly, whereas applying the gastrocnemius muscle force tended to translate the tibia anteriorly. Applying the soleus and gastrocnemius muscle forces together also tended to translate the tibia anteriorly. The average anterior and posterior tibial translations were greatest at 50 degrees of flexion. CONCLUSIONS: The soleus muscle is capable of acting as an agonist for the anterior cruciate ligament and the gastrocnemius muscle can act as an antagonist. CLINICAL RELEVANCE: A better understanding of the agonistic behavior of the soleus muscle on the anterior cruciate ligament may lead to the development of training and rehabilitation strategies that could reduce the incidence of injury and improve function in both patients with anterior cruciate ligament deficiency and patients who have undergone anterior cruciate ligament reconstruction.

Aged↗
PubMedDate not supplied

An ethopharmacological assessment of the effects of zuclopenthixol on agonistic interactions in male mice.

Zuclopenthixol is a thioxanthene derivative which acts as a mixed dopamine D1/D2 receptor antagonist. Although the antiaggressive action of neuroleptic drugs is well known, the effects of zuclopenthixol on agonistic interactions have not been explored and there are no studies comparing acute and subchronic effects of this compound on aggression in rodents. In this work, we examined the action of zuclopenthixol (0.025-0.4 mg/kg), administered acutely or subchronically for 10 days, on agonistic behavior elicited by isolation in male mice. Individually housed mice were exposed to anosmic "standard opponents" 30 min after the drug administration, and encounters were videotaped and evaluated using an ethologically based analysis. After acute treatment, zuclopenthixol (0.2 and 0.4 mg/kg)-treated animals exhibited ethopharmacological profiles characterized by a decrease in offensive behaviors without impairment of motor activity (0.2 mg/kg). In contrast, the antiaggressive action of the highest dose used (0.4 mg/kg) was accompanied by a marked increase of immobility. After subchronic treatment, no tolerance to zuclopenthixol antiaggressive or motor activity was observed. Overall, this behavioral profile is similar to that observed with other typical neuroleptics.

Aggression↗
PubMed2006

The relationship between watching professional wrestling on television and engaging in date fighting among high school students.

CONTEXT: Previous research has found that exposure to violence in the home, community, and electronic media are associated with children's and adolescents' normative expectations concerning the use of violence and with other indicators of the violent behaviors by youth. OBJECTIVE: Our purpose with this study was to examine the relationships between the frequency that high school students reported watching wrestling on television and engaging in date fighting, weapon carrying, and other fighting behaviors. DESIGN: The initial analysis consisted of a cross-sectional study of a simple random sample of high school students, which was followed by a longitudinal analysis of these students over a 6- to 7-month period. SETTING: The setting was all public high schools in 1 city/county system. PARTICIPANTS: We used a simple random sample (N = 2228) of students. MAIN OUTCOME MEASURES: The primary outcome variables included the frequency of date fighting during the previous 12 months and alcohol or other drug involvement associated with the last date fight. RESULTS: There were significant correlations between frequency of watching wrestling on television during the previous 2 weeks and engaging in date fighting, fighting in general, and weapon carrying for both males and females, although the relationships were stronger among females than among males. The frequency of watching wrestling was highest among students reporting date fighting when either the victim or perpetrator had been drinking alcohol or using illegal drugs. When analyzed using logistic regression, the strongest relationships were observed between the frequency of watching wrestling and date-fight perpetration among females in cross-sectional and longitudinal analyses. These findings persisted after adjusting for multiple other factors. CONCLUSIONS: For males and females, the frequency of watching wrestling was highest among students who fought with their dates when alcohol or other drugs were involved. The association between watching wrestling and date fighting was stronger among females than males. The relationship between watching wrestling on television and being the perpetrator of dating violence was also stronger among females and remained consistent over a 6- to 7-month time period.

Adolescent↗
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↗
PubMedDate not supplied

Subtleties of structure-agonist versus antagonist relationships of opioid peptides and peptidomimetics.

The development of novel delta opioid antagonists and delta opioid agonists structurally derived from the prototype delta antagonist TIPP (H-Tyr-Tic-Phe-Phe-OH), is reviewed. Both delta antagonists and delta agonists with extraordinary potency and unprecedented delta receptor selectivity were discovered. Some of them are already widely used as pharmacological tools and are also of interest as potential therapeutic agents for use in analgesia. The results of the performed structure-activity studies revealed that the delta antagonist versus delta agonist behavior of this class of compounds depended on very subtle structural differences in diverse locations of the molecule. These observations can be best explained with a receptor model involving a number of different inactive and active receptor conformations.

Animals↗
PubMed1980

Prevalence of Aspergillus fumigatus in free-living goshawks (Accipiter gentilis atricapillus).

During the fall migration of 1972 and 1973 unusually large numbers of goshawks (Accipiter gentilis atricapillus) were counted at Hawk Ridge in Duluth, Minnesota. These birds were sampled for prevalence of fungi of the genus Aspergillus. Fungi of this genus were recovered from 26 of 49 birds (53%) in 1972 and 4 of 45 (7%) birds in 1973. Aspergillosis was confirmed at necropsy in three wild goshawks in 1972, but none in 1973. The disease was further confirmed at necropsy in 8 of 12 (67%) goshawks trapped in the fall and retained for falconry in 1972 and in 2 of 17 (12%) such birds in 1973. We suggest that the stress of intraspecific agonistic behavior in conjunction with a high density of goshawks and greatly reduced prey base may increase the susceptibility of these hawks to aspergillosis.

Animals↗
PubMed2003

An overview of reported youth violence in Puerto Rico.

OBJECTIVES: The purpose of this paper is to describe the prevalence of school and youth violence in Puerto Rico based on several representative samples surveyed in the Island during the 1990's. BACKGROUND: Reviewing the available data on youth violence is necessary in order to decide the best strategies to follow in developing new ways to prevent and monitor it. METHODS: Three surveys were reviewed in this paper: The Youth Risk Behavior Survey conducted by the Center for Disease Control (1991, 1995, 1997); The Methods for the Epidemiology of Child and Adolescent Mental Disorders Study (1991); and the Youth Survey (1997-98). RESULTS: It was found that the prevalence of reported school violence in Puerto Rico tends to be somewhat lower than the prevalence reported in other sites of the U.S.A. Age and gender has a dramatic influence in the reports of youth violence in Puerto Rico. Male students are three times as likely to carry weapons than females and almost twice as likely to report hurting someone than females. Less than 10% of the male students ages 12-13 report carrying a weapon while fully 30% of those 18 year olds reported carrying a weapon. Being arrested also increases from only 3% in the youngest students surveyed to 10% on the oldest group (18 or older). CONCLUSION: The CDC has recently reported that since the early 90's there has been a decrease in reported school violence in the U.S.A. This analysis of youth surveys replicated a similar tendency for Puerto Rican youngsters. Implications for prevention programs are discussed.

Adolescent↗
PubMed2003

[The social construction of violence in a group of young people of both sexes in a public middle school].

In this article we will address some factors that promote violence in schools from the youth viewpoint. We present an overview of what young people understand about violence; in which way its take places; in what forms they express it; and what aspects they consider more important than others. At the same time, it compares the social construction of violence on both, boys and girls, and describe how violence is interpreted from the gender perspective. The latter means that assumption of violent behavior varies with the gender of the person describing it. In other words, any project that pretends to promote schools free of violence need to deal with gender issues. Finally, I will share a few general considerations about what we may call social construction of violence in young people and its implications for a violence prevention project.

Adolescent↗
PubMed1991

[Violence: its forms and justifications].

This paper addresses the conceptual difference there is between violence and aggression. The former is defined as a manifestation of extemporaneous or inappropriate power or force. The latter is defined as an agonist behavior aimed at causing harm. There can be non-aggressive violence, and non-violent aggression as well. Categorization and discrimination are the processes underlying violent aggression. Unanimous aggression, however, preserves social order: Indeed--according to the social group at stake--justifications for violence are order, justice, and fear. A short discussion on contemporary situation closes the paper.

Aggression↗
PubMedDate not supplied

[Catatonia as an element of submissive behavior in mice during interspecies agonistic interactions].

A catatonia-like state was elicited in male mice with different experience of social interactions, by pinch of scruff of the neck in a suspended state. In submissive males with long experience of defeat the total time of catatonia reaction during test is considerably greater than in aggressive individuals with a long experience of victories. The change of the social status of the individuals resulting from agonistic interactions leads to a change of the catatonia reaction: manifestation of submissive behaviour is accompanied by an increase of total time of catatonia reaction in the test, the aggressive behaviour is accompanied by its decrease.

Aggression↗
PubMed1988

Intercommunity differences in aggression among Zapotec children.

Patterns of play aggression and serious aggression were compared in 2 neighboring Zapotec Indian communities that have different levels of adult violence. Social learning theory provided the basis for predicting that levels of agonistic behavior among children would parallel levels of violence among adults. Ethological methods were employed to observe 3-8-year-old children (N = 48). An examination of physical aggression and nonphysical threatening showed that agonism generally was more severe among the children of the more aggressive community. That is, children from the more aggressive community engaged in more actual fighting (p = .005) and play fighting (p = .0001) than their counterparts from the other community. On the other hand, children from the less aggressive community used more noncontact threatening than the children from the more aggressive community (p = .0001). These findings suggest that community differences in levels of violence are perpetuated as Zapotec children learn community-appropriate patterns for expressing aggression and continue to express these patterns as adults. Possible functions of play fighting are also discussed.

Aggression↗
PubMed1983

Analysis of ultrasonic vocalizations emitted by intruders during aggressive encounters among rats (Rattus norvegicus).

This investigation was concerned with the identification of the ultrasonic vocalizations produced by intruders during aggressive interactions and the role of these signals in agonistic behavior of rats. In the first experiment, experienced resident males were paired with both devocalized and intact vocalizing naive intruder males. Devocalization of the intruder males resulted in a drastic decrease in 50-kHz vocalizations and the elimination of all 22-kHz vocalizations. This almost total absence of ultrasonic vocalizations was not accompanied by any change in resident aggressive behavior or intruder defensive and submissive behavior. In a second experiment, naive intruders were tested with either deafened or intact resident males. Similarly, preventing residents from hearing intruder ultrasounds had no detectable effect on any aggressive behavior. These experiments are not consistent with the correlative evidence that intruder-produced 22-kHz vocalizations inhibit the aggressive behavior of the resident. The results also show that most of the ultrasonic vocalizations emitted during aggressive encounters are probably produced by the intruder.

Aggression↗
PubMed1995

Altered sexual partner preference in male ferrets given excitotoxic lesions of the preoptic area/anterior hypothalamus.

Numerous experiments suggest that perinatal exposure of male vertebrates to testosterone (T), or its estrogenic metabolites, masculinizes aspects of coital function, including males' characteristic preference to seek out and mate with a female as opposed to another male conspecific. Other research has shown that this perinatal action of sex steroids also masculinizes aspects of neuronal morphology in the medial preoptic area/anterior hypothalamus (mPOA/AH). We asked whether neurons of the mPOA/AH contribute to males' preference to mate with a female. The ferret is an ideal species in which to ask this question. When tested in a T-maze after gonadectomy and treatment with estradiol benzoate (EB), female ferrets prefer to approach and receive neck grips from a stimulus male whereas males prefer to approach and neck grip an estrous female. In the minority of trials when EB-treated males approach a stimulus male, they occasionally receive a neck grip to which they display receptive postures as opposed to agonistic behaviors. In Experiment 1 castrated, EB-treated male ferrets which received bilateral infusions of the NMDA excitotoxin, quinolinic acid aimed at the dorsomedial POA/AH, preferred to approach a stimulus male significantly more often than groups of control males which either received a sham lesion, received a unilateral mPOA/AH lesion or in which bilateral infusions of quinolinic aci produced no histologically detectible excitotoxic damage to the mPOA/AH. Males with bilateral mPOA/AH lesions also displayed neck gripping on a significantly lower percentage of trials than control males when they approached the stimulus female. Ovariectomized, EB-treated female ferrets with bilateral mPOA/AH lesions, like control females, preferred to approach and receive neck grips from a stimulus male. The males used in Experiment 1 had never experienced circulating levels of T characteristic of the breeding season. Therefore, in Experiment 2 prepubertally gonadectomized males and females were treated chronically with a high dose of T propionate (TP) and tested several times with a receptive female prior to brain surgery. Males which received bilateral excitotoxic lesions of the mPOA/AH neck gripped and mounted stimulus females significantly less than control males. Again, when given EB followed by T-maze tests of partner preference, males with bilateral mPOA/AH lesions, like sham-operated female controls, preferred to approach the sexually active stimulus male significantly more often than control males, which preferred to approach the stimulus female. Our results suggest that neurons in the mPOA/AH play an important role in the integration of sensory cues which determine heterosexual partner preference in the male ferret, in addition to facilitating masculine coital performance.

Animals↗