The relationship between sleep disturbance and aggressive behaviour among community-dwelling schizophrenia patients: a moderated mesomeric effect model.

OBJECTIVE: Sleep disturbance is the most common concern of patients with schizophrenia and can lead to a poor prognosis, a low survival rate and aggressive behaviour, posing a significant threat to social security and stability. The aim of this study was to explore the mediating role of depression in the relationship between sleep disturbance and aggressive behaviour in people with schizophrenia living in the community, as well as the regulatory role of family intimacy and adaptability. These findings, in turn, may provide a theoretical basis and constructive suggestions for addressing the physical and mental health problems of these patients. METHOD: From September 2020 to August 2021, a convenience sampling method was used to select schizophrenia patients from the community attending follow-up appointments at the Fourth People's Hospital of Pengzhou City, China. The researchers conducted a survey in the form of a star questionnaire. The survey included questions about general demographic data and disease-related questionnaires: the Pittsburgh Sleep Quality Index (PSQI), the revised Chinese version of the Modified Over Aggression Scale (MOAS), the Self-Rating Depression Scale (SDS), and the Family Adaptability and Cohesion Scale, Second Edition. FACES-II and SPSS 21.0 were used to organize and analyse the data. RESULTS: A total of 818 schizophrenia patients living in the community participated in the survey, and 785 valid questionnaires were ultimately collected, for a response rate of 95.97%. The results of multivariate analysis indicated that sex, number of psychiatric medications used, outpatient follow-up, history of hospitalization for mental disorders and sleep disturbances were factors influencing aggressive behaviour. Depression played a partial mediating role between sleep disturbance and aggressive behaviour, and the indirect effect size was 0.043 (57.33% of the total). In addition to sleep disturbance, family intimacy (ß=-0.009, P < 0.01) and adaptability (ß=-0.145, P < 0.001) can significantly predict depression. CONCLUSION: The findings indicate that sleep disturbance in schizophrenia patients in the community is a risk factor for aggressive behaviour, and depression plays a partial mediating role in the relationship among sleep disturbance, aggressive behaviour and family intimacy. In addition, adaptability plays a regulatory role in the relationship between depression and sleep disturbance.

Behavioural phenotype of SYNGAP1-related intellectual disability.

BACKGROUND: SYNGAP1- related intellectual disability (SYNGAP1-ID) is a rare genetic disorder presenting with intellectual disability (ID), epilepsy, maladaptive behaviours and communication challenges. To date, few studies have assessed the context in which these maladaptive behaviours occur. This study aims to investigate the prevalence of problem behaviours, characterise the behavioural phenotype and use well-validated measures to explore variables that maintain the behaviours. METHODS: Our sample includes 19 individuals diagnosed with SYNGAP1-ID and their parents. Parents provided information on behaviours that their children engage in, as well as their general behavioural dispositions. Well-validated measures (e.g., the Repetitive Behaviour Scale-Revised, Sensory Profile-2 and Vineland Adaptive Behaviour Scale) were used. A subset of individuals underwent further direct experimental assessment of their problem behaviour to identify the variables maintaining those problem behaviours. Parental reports were analysed using nonparametric statistical analysis; the direct assessments of individuals' problem behaviour were analysed using visual analysis and validated supplemental measures. RESULTS: All 19 individuals engaged in some form of maladaptive problem behaviour. Ratings of ritualistic, sameness and restricted behaviours measured by the RBS-R were commensurate with individuals diagnosed with idiopathic autism spectrum disorder (ASD) while self-injurious behaviours were endorsed at a higher level in SYNGAP1-ID when compared with idiopathic ASD. The problem behaviours in our cohort of patients with SYNGAP1-ID were maintained by automatic reinforcement and social attention and are positively correlated with atypical sensory responses. CONCLUSIONS: Individuals with SYNGAP1-ID engage in problem behaviours commensurate with other populations (e.g., those with ASD), they exhibit atypical response to sensory stimuli. Problem behaviours were frequently maintained by automatic reinforcement, which may result from a dysregulated sensory system. Children with SYNGAP1-ID may benefit from strategies used in persons with ASD.

Aggressive behaviour and diabetes: A clinical case of atypical metabolic improvement during clozapine treatment.

Aggressive and violent behaviour is a challenging psychiatric emergency to manage, especially among vulnerable categories such as patients with Intellectual Developmental Disorder. Although there is some evidence that clozapine may be useful as an anti-violence compound, its use is limited by common metabolic complications. An adult patient presented with obesity, type II diabetes mellitus, compulsive food intake, severe Intellectual Developmental Disorder, and a treatment-resistant aggressive behaviour. Clozapine was administered resulting in reduced aggressive behaviour. Unexpectedly, a reduction in the food craving as well as a sustained improvement in both anthropometric parameters and glycemic control were observed during the clozapine treatment. Our case report, describes these findings for the first time, highlighting the need for more clinical research to investigate both the efficacy of clozapine in the Intellectual Developmental Disorder populations and its long-term effects with special regard to the metabolic outcomes in this type of patients.

Reduction of aggressive behaviour following hypothalamic deep brain stimulation: Involvement of 5-HT1A and testosterone.

BACKGROUND: Aggressive behaviour (AB) may occur in patients with different neuropsychiatric disorders. Although most patients respond to conventional treatments, a small percentage continue to experience AB despite optimized pharmacological management and are considered to be treatment-refractory. For these patients, hypothalamic deep brain stimulation (pHyp-DBS) has been investigated. The hypothalamus is a key structure in the neurocircuitry of AB. An imbalance between serotonin (5-HT) and steroid hormones seems to exacerbate AB. OBJECTIVES: To test whether pHyp-DBS reduces aggressive behaviour in mice through mechanisms involving testosterone and 5-HT. METHODS: Male mice were housed with females for two weeks. These resident animals become territorial and aggressive towards intruder mice placed in their cages. Residents had electrodes implanted in the pHyp. DBS was administered for 5 h/day for 8 consecutive encounters prior to the interaction with the intruder. After testing, blood and brains were recovered for measuring testosterone and 5-HT receptor density, respectively. In a second experiment, residents received WAY-100635 (5-HT1A antagonist) or saline injections prior to pHyp-DBS. After the first 4 encounters, the injection allocation was crossed, and animals received the alternative treatment during the next 4 encounters. RESULTS: DBS-treated mice showed reduced AB that was correlated with testosterone levels and an increase in 5-HT1A receptor density in the orbitofrontal cortex and amygdala. Pre-treatment with WAY-100635 blocked the anti-aggressive effect of pHyp-DBS. CONCLUSIONS: This study shows that pHyp-DBS reduces AB in mice via changes in testosterone and 5-HT1A mechanisms.

The Relation Between the Power of Prefrontal Gamma in Rest-state EEG Under Normal Sleep and Reactive Aggression Behaviour After Sleep Deprivation.

Whether sleep deprivation affects aggressive behaviour is still under debate. The present study examined the influence of individual differences in reactive aggressive behaviour after sleep deprivation and preliminarily explored an electrophysiological marker to identify individuals with more aggressive behaviour after sleep deprivation. Thirty participants performed the Taylor Aggression Paradigm task under two sleep conditions: normal sleep (NS, one night of regular sleep) and total sleep deprivation (SD, 30 h of wakefulness), and 5-minute resting-state electroencephalogram (EEG) acquisition was completed under the NS condition. The results found that although sleep deprivation did not have significant effects on aggressive behaviour in the overall analysis, the participants can be classified as an increased group (n = 16) and a no-increased group (n = 14) by different changes in the two sleep conditions (SD-NS). In addition, prefrontal gamma (γ) power was significantly lower in the increased group than in the no-increased group, which may reflect the difference in ability on inhibition. Furthermore, more critical is that γ power was significantly negatively correlated with change in the reactive aggressive behaviour. These results indicate that the effect of SD on reactive aggression varies between individuals, and prefrontal γ power may be an effective electrophysiological marker for identifying people at risk of aggressive behaviour after SD.

Bioinformatics analysis of the clinicopathological and prognostic significance of BAG3 mRNA in gynecological cancers.

BAG3 is a co-chaperone BAG family protein that plays important roles in protein homeostasis, cell survival, cell motility, and tumour metastasis. This study aimed to clarify the clinicopathological and prognostic implications of BAG3 mRNA expression in tumours. We performed bioinformatics analysis on BAG3 mRNA expression using TCGA, XIANTAO, UALCAN, and Kaplan-Meier plotter databases. BAG3 mRNA expression was downregulated in breast and endometrial cancers and positively correlated with favourable PAM50 subtyping in breast cancer，clinical stage and short overall survival in ovarian cancer and negatively correlated with T stage, clinical stage, and histological grade in cervical and endometrial cancers. The top BAG3-related pathways included ligand-receptor interactions and activity, DNA packaging and nucleosomes, hormonal responses, membrane regions, microdomains and rafts, and endosomes in breast cancer; ligand-receptor interactions, transmembrane transporters and channels, cell adhesion, and keratinisation in cervical cancer; ligand-receptor interactions, anion transmembrane transporters, lipoproteins, keratinisation, cell adhesion, and protein processing in endometrial cancer; metabolism of porphyrin, chlorophyll, pentose, uronic acid, ascorbate, and alternate and cell adhesion in ovarian cancer. BAG3 expression could represent a potential marker for carcinogenesis, histogenesis, aggressive behaviours, and prognosis in gynecological cancers.IMPACT STATEMENTWhat is already known on this subject? BAG3 regulates cell activity, autophagy, and resistance to apoptosis through multiple domains and plays an important role in tumour development. BAG3 positively regulates tumour cell invasion and migration in cervical and ovarian cancers.What do the results of this study add? BAG3 expression is closely associated with histogenesis, clinicopathology, and prognosis in gynecological cancers and is involved in signalling pathways associated with the control of cell proliferation, migration, invasion, and drug resistance in tumours.What are the implications of these findings for clinical practice and/or further research? Abnormal BAG3 expression can be employed as a possible marker of tumour development, invasion, and prognosis, providing new ideas for treating cancer.

Dietary supplements for aggressive behaviour in people with intellectual disabilities: A randomised controlled crossover trial.

BACKGROUND: Aggressive incidents are common in people with intellectual disabilities. Therefore, we aimed to assess whether supplementation of multivitamins, minerals, and omega-3 fatty acids (FA) reduces aggressive incidents. METHODS: We conducted a randomised, triple blind, placebo controlled, single crossover intervention trial. People with intellectual disabilities or borderline intellectual functioning, between 12 and 40 years of age, and showing aggressive behaviour were included. Participants received either a daily dose of dietary supplements, or placebo. Primary outcome was the number of aggressive incidents, measured using the Modified Overt Aggression Scale (MOAS). RESULTS: there were 113 participants (placebo, n = 56), of whom 24 (placebo, n = 10) participated in the crossover phase of the trial. All 137 trajectories were included in the analyses. There was no significant difference in mean number of aggressive incidents per day between those assigned to supplements and those who received placebo (rate ratio = 0.93: 95% Confidence Interval [CI] = 0.59-1.45). CONCLUSION: In this pragmatic trial, we did not find significant differences in the outcomes between the supplement and placebo arms. The COVID-19 pandemic started midway through our trial, this may have affected the results.

Behavioural and neurochemical effects after repeated administration of N-ethylpentylone (ephylone) in mice.

N-ethyl-pentylone (NEP), also known as 'ephylone' and N-ethylnorpentylone, has been identified as one of the most recent novel psychostimulants to emerge into the illicit drug market and it has been associated with some intoxications and even fatalities. However, little is known about the consequences of its repeated consumption as well as the role of the monoaminergic system in such consequences. Thus, the aim of our study was to investigate the neurochemical profile and the behavioural effects after both acute and repeated NEP exposure. Male OF1 mice were acutely (1, 3, 10 mg/kg, i.p.) or repeatedly (1, 3, 10 mg/kg, i.p., 5 days, twice/day) exposed to NEP, and anxiety-like behaviour, aggressiveness, social interaction, depressive-like symptoms, body temperature, changes in monoaminergic enzymes and neurotransmitters levels as well as ΔFosB in striatum and prefrontal cortex (PFC) from post-mortem tissue were analysed short after drug-exposure or during drug-withdrawal. Acute administration of NEP induced anxiolytic effects but also an aggressive behaviour and social exploration deficits in mice, which persist during NEP-withdrawal. Moreover, NEP induced hyperthermia as well as depressive-like symptoms after repeated administrations that may be related to the decrease in serotonin and noradrenaline levels observed in striatum and PFC. Finally, the long-term increase in ΔFosB levels in striatum after NEP chronic exposure points to a high risk of dependence. Altogether indicates that NEP consumption induces different neurological and neuropsychiatric disorders accompanied by changes in the monoaminergic system, posing a threat to public health.

Colour patterns influence symbiosis and competition in the anemonefish-host anemone symbiosis system.

Colour patterns in fish are often used as an important medium for communication. Anemonefish, characterized by specific patterns of white bars, inhabit host anemones and defend the area around an anemone as their territory. The host anemone is used not only by the anemonefish, but also by other fish species that use anemones as temporary shelters. Anemonefish may be able to identify potential competitors by their colour patterns. We first examined the colour patterns of fish using host anemones inhabited by Amphiprion ocellaris as shelter and compared them with the patterns of fish using surrounding scleractinian corals. There were no fish with bars sheltering in host anemones, although many fish with bars were found in surrounding corals. Next, two fish models, one with white bars and the other with white stripes on a black background, were presented to an A. ocellaris colony. The duration of aggressive behaviour towards the bar model was significantly longer than that towards the stripe model. We conclude that differences in aggressive behaviour by the anemonefish possibly select the colour patterns of cohabiting fish. This study indicates that colour patterns may influence not only intraspecific interactions but also interspecific interactions in coral reef ecosystems.

Selection for winners impacts the endocrine system in the Siamese fighting fish.

In southeast Asia, males of the Siamese fighting fish, Betta splendens, have been selected across centuries for winning paired staged fights and previous work has shown that males from fighter strains are more aggressive than wild-types. This strong directional selection for winners is likely to have targeted aggression-related endocrine systems, and a comparison between fighter and wild-type strains can bring into evidence the key hormones implicated in aggression. Here, we compared the plasma levels of the androgen 11-ketotestosterone (KT) and of the corticosteroid cortisol (F) in F2 males of a fighter and a wild-type strain raised under similar laboratory conditions. We show that F was generally lower in fighter as compared with wild-type males, while no overall differences in KT levels were detected between strains. When presented with a mirror-induced aggressive challenge, post-fight levels of F increased but more significantly so in wild-type males, while KT increased in males of both strains. After the challenge, fighter males had higher levels of KT as compared with wild-type males, while the pattern for F was opposite. As compared with animals in social groups, wild-type males placed under social isolation had lower F levels, while KT decreased for fighters. Taken together, this data suggests that while wild-type males responded to aggression with an increase in circulating levels of both androgens and corticosteroids, males selected for winning fights maintained a blunt F response, increasing only KT levels. These data agree with the hypothesis that a combination of high levels of androgens and low levels of corticosteroids is associated with high aggression. Overall, these results seem to indicate that selection for winning had a stronger impact in the hypothalamus-pituitary-interrenal axis than in the hypothalamus-pituitary-gonadal axis in B. splendens.

The association between pupils´ aggressive behaviour and burnout among Danish school teachers - the role of stress and social support at work.

BACKGROUND: Pupils´ aggressive behaviour towards teachers is a serious problem which is slowly gaining attention and has been found to be linked to burnout. However, prospective studies investigating the role of stress and social support from colleagues and supervisor are lacking. Therefore, the aims of the present study were 1. to investigate the association between pupils´ aggressive behaviour and burnout among Danish primary and lower secondary school teachers, 2. to investigate whether the association between pupils´ aggressive behaviour and burnout depends on the level and duration of stress, and 3. to investigate whether social support from colleagues or a supervisor at the work place has a mitigating effect on the association between pupils´ aggressive behaviour and burnout among teachers. METHODS: This study is a longitudinal study using data from 1198 teachers collected in two survey rounds at an interval of 1-year. Teacher-reported aggressive behaviour in pupils measured as harassment, threats, and violence towards teachers was collected at baseline. Burnout was measured at follow-up. The analyses were performed using multilevel logistic regression. RESULTS: Statistically significant associations between harassment, threats, or violence and burnout 1 year later were found (all ORs 1.6) after adjustment for potential confounders. After further adjustment for stress, the estimates attenuated to ORs between 1.4 and 1.5, and were also statistically significant. Pupils´ aggressive behaviour in combination with low support from colleagues increased the risk of burnout, whereas the risk of burnout increased among those experiencing pupils´ aggressive behaviour in combination with receiving high support from the supervisor. CONCLUSIONS: The results indicate associations between all three types of pupils´ aggressive behaviour and burnout among teachers in Danish primary and lower secondary schools. Stress explained only a minor part of the association between teachers' perceptions of pupils' aggressive behaviour and burnout in teachers, and the results regarding social support were conflicting. The results of this study emphasize the growing need for preventive initiatives directed towards pupils´ aggressive behaviour, and future research should focus on exploring in depth how to support and prevent burnout in teachers exposed to aggressive behaviour.

Fathers' Mental Health and Children's Aggressive Behaviour A Study Based on Data from the Norwegian Mother, Father and Child Cohort Study (MoBa).

The aim of the study was to examine the association between fathers' prenatal psychological distress and children's aggressive behaviour in terms of hitting others, and how children's age, gender and temperament affect this association. The study is based on data from 20,155 fathers and mothers from the Norwegian Mother, Father and Child Cohort Study (MoBa). Fathers and mothers completed questionnaires at 17 or 18 weeks of gestation and mothers at children's age 18 months, and 3 and 5 years. Fathers' prenatal psychological distress was assessed by the 5-item Symptom Checklist (SCL-5), and children's temperament by 12 items from the Emotionality Activity Sociability (EAS) Temperament Survey. Increasing prenatal psychological distress in fathers was associated with an increase of hitting from 18 months to 3 years of age in boys. Children's temperament did not affect the association between fathers' prenatal psychological distress and children's aggressive behaviour.

Glucocorticoid receptor gene (NR3C1) is hypermethylated in adult males with aggressive behaviour.

Aggressive behaviour is a serious threat to the personal safety and property of others due to the potential that the assailant may hurt people, himself/herself or objects, and aggression has always been one of the focuses of research and concern. Accumulating evidence suggests that the hypothalamic-pituitary-adrenal (HPA) axis plays a major role in the development, elicitation, enhancement and genetic susceptibility of aggressive behaviour in humans and animals. GR (NR3C1) plays a crucial role in controlling HPA activity, which directly affects aggressive behaviour. Here, we investigated the methylation state of the NR3C1 gene promoter region and its role in aggressive behaviour in adult males for the first time by applying a case-control approach (N = 106 controls, N = 104 patients). Methylation of NR3C1 was measured in peripheral blood samples at exons 1D, 1B and 1F via sodium bisulfite treatment combined with the MethylTarget method. Methylation of the NR3C1 gene was significantly correlated with aggressive behaviour, and the methylation levels of 1D, 1B and 1F were upregulated in the aggressive behaviour group, intentional injury subgroup and robbery subgroup, and the significance varied. In addition, multiple CpG sites were found to be significantly associated with aggressive behaviour. These results suggest that epigenetic aberrations of NR3C1 are associated with aggressive behaviour, and epigenetic processes might mediate aggressive behaviour by affecting the activity of the HPA axis. This correlative study between DNA methylation of the NR3C1 gene and aggressive behaviour in patients may be helpful for forensic assessments.

Life history of aggression in Anastatus disparis (Hymenoptera: Eupelmidae) with extreme male-male combat.

Aggressive behaviour is common in animals and typically has lifetime consequences. As younger males have higher residual reproductive value than older males and lose more from injuries than older males do, the propensity for fighting tends to increase with age in many empirical reports and species. However, fighting patterns in those empirical reports cannot confirm the hypothesis that individuals cannot readily inflict injuries on their opponents. To address this shortcoming, a parasitoid wasp species, Anastatus disparis (Hymenoptera: Eupelmidae), was used as an experimental model to explore the characteristics of aggression from a life-history perspective; this wasp exhibits extreme fighting, resulting in contestants experiencing injury and death. Results showed that the energetic costs of fighting to injury significantly shortened life and caused the loss of most mating ability. Inconsistent with general predictions, the frequency and intensity of fighting in A. disparis significantly decreased with male age. Further study results showed significantly more young males were received by and successfully mated with virgin females, and most genes related to energy metabolism were downregulated in aged males. Our study provided supporting evidence that young A. disparis males show more aggression likely because of their resource holding potential and sexual attractiveness decline with age.

Longitudinal relationships among interpersonal openness trait, hostile attribution bias, and displaced aggressive behaviour: Big Five treated as covariates.

Displaced aggressive behaviour is associated with many negative outcomes. Although certain personality traits predict displaced aggressive behaviour, the uniquely longitudinal effect of indigenous interpersonal traits on displaced aggressive behaviour is ignored. To address this gap, we explored the longitudinal relationship among an indigenously interpersonal trait of China (interpersonal openness), hostile attribution bias, and self-reported displaced aggressive behaviour. Additionally, we tested whether hostile attribution bias mediated the relationship between interpersonal openness and self-reported displaced aggressive behaviour. The Interpersonal Self-Support Scale for Undergraduate Students, Word Sentence Association Paradigm for Hostility, Displaced Aggression Questionnaire, and the NEO Personality Inventory-3 were administered to 942 undergraduates on two occasions, 6 months apart. A cross-lagged model showed that, after controlling for the Big Five personality traits, interpersonal openness predicted subsequent hostile attribution bias, and hostile attribution bias predicted self-reported displaced aggressive behaviour 6 months later. Hostile attribution bias at time 2 mediated the relationship between interpersonal openness at time 1 and self-reported displaced aggressive behaviour at time 2. These results were consistent with the interpersonal self-support theory's appraisals of interpersonal openness, and they extended the social information processing and general aggression models to explain displaced aggressive behaviour.

Testosterone, personality traits and aggressive driving among young male drivers.

INTRODUCTION: Psychological testing to examine potentially aggressive behaviour is a gold standard, but it is not sufficient. Testosterone might increase an aggressive behaviour. AIM: The aim of this study was to evaluate whether testosterone along with psychological assessment of fitness to drive could help to identify aggressive drivers. METHODS: Male participants (n=150) aged from 20 to 25, who possessed a driving license and drive at least 100 km per week, were evaluated in this study using an Inventory of traffic-relevant personality characteristics, the Sensation Seeking Scale and the Buss-Durkee Aggression Inventory. Saliva was collected for testosterone and cortisol measurements. The five binomial logistic models with dependent variables Caused an accident, Driving license taken away, Court trial, Intoxicated driving and Sporty self-report were tested in this study. RESULTS: The 'Intoxicated driving' model, was found to be statistically highly significant, explaining 48.8 % of the dependent variable's variance (χ2(16)=36.145, p<0.01). In this model with sensation seeking, actual testosterone and their interaction was highly significant and explained 20.4 % of intoxicated driving variability (χ2(3)=14.283, p<0.01). This was higher than sensation seeking scores only. CONCLUSION: To conclude, salivary testosterone might prove a biological marker that improves the identification of those with a high probability of aggressive driving or its subtypes (Tab. 3, Ref. 53).

Complex visual analysis of ecologically relevant signals in Siamese fighting fish.

We currently have limited knowledge about complex visual representations in teleosts. For the specific case of Siamese fighting fish (Betta splendens), we do not know whether they can represent much more than mere colour or size. In this study, we assess their visual capabilities using increasingly complex stimulus manipulations akin to those adopted in human psychophysical studies of higher-level perceptual processes, such as face recognition. Our findings demonstrate a surprisingly sophisticated degree of perceptual representation. Consistent with previous work in established teleost models like zebrafish (Danio rerio), we find that fighting fish can integrate different features (e.g. shape and motion) for visually guided behaviour; this integration process, however, operates in a more holistic fashion in the fighting fish. More specifically, their analysis of complex spatiotemporal patterns is primarily global rather than local, meaning that individual stimulus elements must cohere into an organized percept for effective behavioural drive. The configural nature of this perceptual process is reminiscent of how mammals represent socially relevant signals, notwithstanding the lack of cortical structures that are widely recognized to play a critical role in higher cognitive processes. Our results indicate that mammalian-centric accounts of social cognition present serious conceptual limitations, and in so doing they highlight the importance of understanding complex perceptual function from a general ethological perspective.

Effect of variation in objective resource value on extreme male combat in a quasi-gregarious species, Anastatus disparis.

BACKGROUND: Aggressive behaviour is widely observed in animal kingdom, which compete for resources such as territory, food and mates. Resource value is the most important non-strategic factor influencing fighting behaviour, and may vary among contests and contestants. Usually, contestants adjust their fighting behaviour when the resource value changes, and as potentially damaging and energetically costly, individuals of most species usually avoid conflict escalation. However, in a quasi-gregarious egg parasitoid, Anastatus disparis (Hymenoptera: Eupelmidae), mates are valuable resources and females mate only once; thus, males engage in frequently extreme combat behaviour to acquire mating opportunities, even in the absence of females. In this study, we attempted to test whether males of this species have the ability to adjust their fighting behaviour in response to changes in the objective value of female. RESULTS: Our results suggested that objective resource value in A. disparis is likely to be influenced by female mating status rather than by fecundity. Consistent with a number of empirical studies, A. disparis males adjusted their fighting behaviour according to the value of the contested resources: males significantly increased their fighting intensity to acquire mating opportunities with virgin females but decreased their fighting intensity for mated females. We also found that rather than chemical cues, visual cues and physical sexual contact appear to play a role in determining males' ability to detect variation in female mating status. CONCLUSIONS: Our study suggested that although in this species, males have evolved extreme fighting behaviour and females are valuable resources, males do not always escalate fighting behaviour in competition for mating with a female. Valuable resources and variation in resource value were detected and estimated by A. disparis males, which then adjusted their fighting behaviour accordingly and to some extent avoided incoming fighting costs.

The psychic readiness for destruction among contemporary adolescents.

AIMS AND OBJECTIVES: To verify the existence of psychic readiness for destruction among adolescent girls and to determine how psychic readiness for destruction is related to suicidal or violent behaviour in adolescence. BACKGROUND: The psychic readiness for destruction can be treated as a generalised tendency (personality disposition) to behave in a way that increases the probability of negative consequences which directly and indirectly threaten one's life, health and its quality. DESIGN: A retrospective cross-sectional study. METHODS: The study involved 140 participants, aged 13-17, including 40 girls after suicide attempts (GS group), 40 girls using violence against others (GA group) and 60 girls without destructive behaviour at all (CG group). To measure psychic readiness for destruction, the polish adaptation of the Chronic Self-Destructiveness Scale (CS-DS) by Kelly was used. RESULTS: No significant differences were found between the GS group and GA group. A significant difference was found between the girls who engage in interpersonal violence (GA) and the control group (CG). In this case, the results showed a significantly higher score among those participants who were involved in extremely aggressive behaviours. A similar trend was also observed when comparing the group of girls who attempted suicide (GS) with the CG. CONCLUSIONS: Based on the conducted analyses, a clear trend was observed in consistency of destructive behaviours (tendency for destruction)-both active (seeking to violate norms, risky behaviours) and passive (omission, neglect) among the girls from both groups indicating even a single act of this kind (no significant differences between the groups). RELEVANCE TO CLINICAL PRACTICE: Due to the complex nature of readiness for destruction and its negative consequences on health, it is imperative to investigate the risk factors for the tendency for destruction and to conduct health education among adolescents.

Interaction effects of pen environment and sex on behavior, skin lesions and physiology of Windsnyer pigs.

OBJECTIVE: The study was carried to determine the interaction effects of pen enrichment and sex on behavioral activities, skin lesions and physiology of Windsnyer pigs. METHODS: Forty-eight growing Windsnyer pigs of both sex, with an average initial body weight of 21.6 (±9.01) kg were used. Four pigs were randomly assigned to either enriched or barren pens at a stocking density of 0.35 m2/pig. Enriched pens contained 2 L bottles filled with stones and suspended at head level on ropes stretching across the pens. In addition, two plastic balls (90 mm in diameter) and 500 mL bottles (235 mm long) were placed on the floor of each enriched pen. RESULTS: Pigs in barren environments had higher heart rates (p<0.001) than those in enriched pens. There was an interaction of pen environment and sex on rectal temperature (p<0.001). Females in enriched pens had higher rectal temperatures (p<0.05) than females in barren pens. There was no interaction of pen environment and sex on time spent eating and drinking (p>0.05). Time spent bullying was influenced (p<0.05) by pen environment and sex. Female pigs in barren environment spent more time on bullying than females in enriched pens. There was an interaction of pen environment and sex on time spent lying down and walking (p<0.05). Female pigs in enriched pens spent more time lying down than females in barren pens. Males in barren pens spent more time walking than males in enriched pens while no effect of pen environment was observed in females. There was an interaction of pen environment and sex on the number of skin lesions in the head, neck and shoulder region and other parts of the body (p<0.05). CONCLUSION: It was concluded that pen enrichment reduced the number of skin lesions and anti-social behaviors, especially for female pigs. There is a need, therefore of housing indigenous pigs under confinement.