Effects of group stability on aggression, stress and injuries in breeding rabbits

On Swiss rabbit breeding farms, group-housed does are usually kept singly for 12 days around parturition to avoid pseudograviclity, double litters and deleterious fighting for nests. After this isolation phase there is usually an integration of new group members. Here we studied whether keeping the group composition stable would reduce agonistic interactions, stress levels and injuries when regrouping after the isolation phase. Does were kept in 12 pens containing 8 rabbits each. In two trials, with a total of 24 groups, the group composition before and after the 12 days isolation period remained the same (treatment: stable, S) in 12 groups. In the other 12 groups two or three does were replaced after the isolation phase by unfamiliar does (treatment: mixed, M). Does of S-groups had been housed together for one reproduction cycle. One day before and on days 2, 4 and 6 after regrouping, data on lesions, stress levels (faecal corticosterone metabolites, FCM) and agonistic interactions were collected and statistically analysed using mixed effects models. Lesion scores and the frequency of agonistic interactions were highest on day 2 after regrouping and thereafter decrease in both groups. There was a trend towards more lesions in M-groups compared to S-groups. After regrouping FCM levels were increased in M-groups, but not in S-groups. Furthermore, there was a significant interaction of treatment and experimental day on agonistic interactions. Thus, the frequency of biting and boxing increased more in M-groups than in S-groups. These findings indicate that group stability had an effect on agonistic interactions, stress and lesions. (C) 2012 Elsevier B.V. All rights reserved.

A test of genetic association among male nuptial coloration, female mating preference, and male aggression bias within a polymorphic population of cichlid fish

Both inter- and intrasexual selection have been implicated in the origin and maintenance of species-rich taxa with diverse sexual traits. Simultaneous disruptive selection by female mate choice and male-male competition can, in theory, lead to speciation without geographical isolation if both act on the same male trait. Female mate choice can generate discontinuities in gene flow, while male-male competition can generate negative frequency-dependent selection stabilizing the male trait polymorphism. Speciation may be facilitated when mating preference and/or aggression bias are physically linked to the trait they operate on. We tested for genetic associations among female mating preference, male aggression bias and male coloration in the Lake Victoria cichlid Pundamilia. We crossed females from a phenotypically variable population with males from both extreme ends of the phenotype distribution in the same population (blue or red). Male offspring of a red sire were significantly redder than males of a blue sire, indicating that intra-population variation in male coloration is heritable. We tested mating preferences of female offspring and aggression biases of male offspring using binary choice tests. There was no evidence for associations at the family level between female mating preferences and coloration of sires, but dam identity had a significant effect on female mate preference. Sons of the red sire directed significantly more aggression to red than blue males, whereas sons of the blue sire did not show any bias. There was a positive correlation among individuals between male aggression bias and body coloration, possibly due to pleiotropy or physical linkage, which could facilitate the maintenance of color polymorphism.

Validation of a paradigm to measure instrumental aggression (iap) on a sample of male adolescents with adjustment problems

Aggressive behavior can be classified in hostile and instrumental aggressions (anderson & bushman, 2002). this classification is mostly synonymously used with reactive and proactive aggression, whereas the differences between hostile and instrumental aggression lie on three dimensions, the primary goal, amount of anger and planning and calculation(bushman & anderson, 2001). although there are rating instruments and experimental paradigms to measure hostile aggression, there is no instrument to measure instrumental aggression. the following study will present an account to measure instrumental aggression with an experimental laboratory paradigm. the instrument was firstly tested on two samples of normal young adolescents (n1 = 100; amage. = 19.14; n2 = 60; amage. = 21.46). the first study revealed a strong correlation with a laboratory aggression paradigm measuring hostile aggression, but no correlations with self-reported aggression in the buss and perry questionnaire. these results were replicated in a second study, revealing an additional correlation with aggressive but not adaptive assertiveness. secondly the instrument was part of the evaluation of the reasoning and rehabilitation program r&r2 (ross, hilborn & lidell, 1984) in an institution for male adolescents with adjustment problems in switzerland. the r&r2 is a cognitive behavioral group therapy to reduce antisocial and promote prosocial cognitions and behavior. the treatment group (n= 16; rangeage = 15-17) is compared to a no treatment control group (n=24; rangeage = 17-19) preand post- treatment. further aggressive behavior was surveyed and experimentally measured. hostile rumination, aggressive and adaptive assertiveness, emotional and social competence were included in the measurement to estimate construct validity.

Leben im Erziehungsheim – eine Kamerabrillenstudie: Aggression und Konflikt in Umwelten frühadoleszenter Jungen und Mädchen

Heimjugendliche sind einer Mehrfachbelastung ausgesetzt und fordern ihre Erzieherinnen und Erzieher. Mit einer innovativen Kamerabrillenmethode werden die Umwelten von aggressiven Heimjugendlichen aus deren räumlichen Perspektive erfasst. Das Buch vermittelt Grundlagenwissen zu Aggression und Konflikt, führt in die Kamerabrillenmethodik ein und gibt einen Einblick in den Alltag eines Erziehungsheims

The additive and interactive roles of aggression, prosocial behavior, and social preference in predicting resource control in young children

Distinguishing between physical and social aggression, this study examined whether the predictive effect of aggression on resource control a) is moderated by prosocial behavior and b) corresponds to a linear or a curvilinear trend. Moderating effects of children’s social preference among peers and child sex in this context were also tested. Based on a sample of 682 kindergarten children (348 girls; average age 72.7 months, 3.6 SD), multilevel regressions revealed additive linear effects of social preference and prosociality on resource control. Moderate (but not high) levels of social aggression also facilitated resource control for disliked children. There was no such threshold effect for well liked children, who increasingly controlled the resource the more socially aggressive they were. In contrast, physical aggression hampered resource control unless used very modestly. The present study has a number of positive features. First, the distinction between physical and social aggression improves our understanding of the relation between aggression and social competence and sketches a more differentiated picture of the role of different forms of aggression in resource control. Second, this study combines the concept of resource control with the concept of social preference and investigates curvilinear effects of aggression. Third, the direct observation of resource control in the Movie Viewer increases the internal validity of this study.

Aggression und Konflikt im Erziehungsheim. Eine Kamerabrillenstudie

Kinder und Jugendliche mit massiven Verhaltensstörungen werden oft in Erziehungsheime für sozial benachteiligte und verhaltensauffällige Jugendliche überwiesen, in welchen abweichendes Verhalten behandelt und familiäre Risikofaktoren korrigiert werden sollen. In der Studie wurden die Umwelten von acht Jugendlichen in Erziehungsheimen sowie einer Kontrollgruppe von vier nicht-aggressiven Jugendlichen untersucht. Die Jugendlichen trugen Kamerabrillen, mit welchen sie ganze Tagesverläufe aufnahmen und so das Geschehen in den Lebensbereichen Familie, Schule, Freizeit und Erziehungsheim aus ihrer räumlichen Perspektive registrierten. Mit ergänzenden Methoden wurde zudem das Wahrnehmen und Erleben der Jugendlichen erfragt. Die Ergebnisse deuten darauf hin, dass die Heimjugendlichen im Vergleich zur Kontrollgruppe über einen kleineren Streifraum verfügen, weniger bedeutsame Interaktionspartnerinnen bzw. Interaktionspartner haben und auch weniger mit Gleichaltrigen interagieren. Im Vergleich mit den Kontrolljugendlichen haben sie außerdem häufiger Konflikte und sind öfters Täterinnen oder Täter sowie auch Opfer von aggressiven Handlungen.

Aggression und soziale Interaktion im Erziehungsheim

In einer Kamerabrillenstudie werden die sozialen und materiellen Umwelten von Jugendlichen, die in Erziehungsheimen für verhaltensauffällige und sozial beeinträchtigte Kinder und Jugendliche leben, untersucht und mit einer Kontrastgruppe nicht verhaltensauffälliger, zuhause lebender Jugendlichen verglichen. Die Ergebnisse deuten darauf hin, dass Heimjugendliche über einen eingeschränkten Streifraum verfügen, weniger mit Peers interagieren und mehr Aggression ausgesetzt sind. Für den Erfolg der Heimerziehung ist es zentral, Peers nicht unbeaufsichtigt zu lassen, weil durch eine negative Peerbeeinflussung der Erfolg der Intervention geschwächt wird.

Aggression, impulsivity and serotonin in drug dependence

Aggression, impulsivity, and central serotonergic function were evaluated in two groups of human volunteers; one group having a history of substance dependence (DRUG+) and another group with no drug use history (DRUG$-$). The hypothesis was that DRUG+ subjects would be more aggressive, more impulsive, and have attenuated serotonergic function. Results showed that DRUG+ subjects behaved more aggressively in a computer paradigm of aggression and also reported more aggression on questionnaires than DRUG$-$ subjects. In a computer paradigm of impulsivity, the DRUG+ group showed a lesser ability to delay gratification than the DRUG$-$ group in the last session of testing. The DRUG+ subjects also reported more venturesomeness and problems associated with low impulse control on questionnaires. Serotonergic function was measured through the neuroendocrine and hypothermic response to an orally administered serotonin (5-HT) agonist specific to the 5-HT$\rm\sb{1A}$ receptor subtype (ipsapirone). The neuroendocrine responses did not differ between DRUG$\pm$ groups, indicating no difference in the sensitivity of the presynaptic or postsynaptic 5-HT$\rm\sb{1A}$ receptors. An unexpected result was that the indicator hormone, cortisol, was at a lower baseline level in the DRUG+ group than the DRUG$-$ group. Lowered cortisol levels have been previously noted in children at high risk foul antisociality and future drug use. A principal components analysis including impulsivity, aggression, and serotonergic function measures produced three unique factors. The factors, Antisocial Tendency and Self-Control and Serotonergic Function combined to produce a significant regression equation explaining 36% of variability in the DRUG$\pm$ groups. These factors included measures of aggression, impulsivity, mood, and educational attainment. These results suggest that the current measures of aggression and impulsivity were predictive of a drug dependence disorder but that neuroendocrine function is not yet a useful indicator of drug dependence status. ^

Ein aggressiver Patient in meinem Dienst - Teil 1: Theorie, Epidemiologie und Pathophysiologie zur Aggression

Quintessenz • Jeder zweite Arzt erlebt im Laufe seiner Berufstätigkeit Gewalt. • Höchstes Gewaltrisiko haben medizinisches Personal in Ausbildung, weibliche Angestellte und Mitarbeiter in der Psychiatrie und den Notfallzentren. • Es gibt ex- und intrinsische Risikofaktoren für aggressives Verhalten von Patienten und Angehörigen gegenüber medizinischem Personal. • Internistische, neurologische und psychiatrische Störungen (inklusive Alkohol-/Drogenintoxikation) sowie medikamentöse Therapien können von aggressiven Verhaltensweisen begleitet sein. • Auf neurobiologischer Ebene handelt es sich um ein Ungleichgewicht im System des frontalen Cortex, anterioren Gyrus cinguli und der Amygdala. • Folgen eines Gewaltakts reichen von körperlichen und psychischen Problemen des Betroffenen bis hin zu ständigen Personalwechseln, Rekrutierungsproblemen und Wettrüsten der Institutionen. • Es wird eine «Null-Toleranz-Politik» gegen Gewalt im medizinischen Bereich und die Teilnahme an Kursen für Aggressionsmanagement empfohlen

Ein aggressiver Patient in meinem Dienst – Teil 2: Behandlung von und Umgang mit Aggression im klinischen Setting

Quintessenz • Das Erkennen von Frühwarnzeichen, Erheben einer Risikoeinschätzung bei Eintritt und der professionelle Umgang mit aggressiven Verhaltensweisen können zu Schadensbegrenzung und geringerem Verletzungsrisiko bei Patienten, Angehörigen und medizinischem Personal beitragen. • Nicht zögern bei pharmakotherapeutischen und nichtmedikamentösen, der Sicherheit dienenden Massnahmen gegen Gewalt und Aggression. • Bei selbst- und fremdaggressivem Verhalten werden Krisengespräch und Kriseninterventionsmassnahmen in der Regel durch einen psychiatrischen Dienst, auf der psychiatrischen Abteilung Isolations- und Zwangsmassnahmen ausgeführt. • Bei Selbst- und Fremdgefährdung im Rahmen einer psychischen Störung und/oder Intoxikation können die Anordnung einer fürsorgerischen Unterbringung und Einweisung in eine psychiatrische Klinik in Begleitung der Sanität und/oder Polizei erforderlich sein. • Die Teilnahme an Kursen für Aggressionsmanagement ist insbesondere für Personal von Psychiatrie und Notfallzentren empfohlen.