809 resultados para AGGRESSION


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The period between offspring birth and recruitment into the breeding population is considered one of the least understood components of animal life histories. Yet, examining this period is essential for studies of parental care, dispersal, demography, and life histories. Studies of the pre-reproductive period are particularly few in tropical regions, where the organization of life histories are predicted to differ compared to northern hemisphere species. For my dissertation I used radio-telemetry, mark-resighting, and field observations to study the pre-reproductive period in a Neotropical bird, the western slaty-antshrike (Thamnophilus atrinucha), in Panama. First, I found that parental care after offspring left the nest (the post-fledging period) was greater than care during the nestling period. Prolonged care resulted in a clear trade-off for parents as they did not nest again until fledglings from the first brood were independent. Parents fed offspring for a prolonged duration during the post-fledging period and higher post-fledging survival was observed compared to many northern hemisphere species. Second, I observed that offspring that remained with parents for longer periods on the natal territory had higher survival both while on the natal territory and after dispersal compared to those dispersing earlier. Parental aggression towards offspring increased with offspring age and offspring dispersed earlier when parents renested. Contrary to other family living species, only a small proportion of antshrike offspring remained on the natal territory until the following year and all dispersed to float. Floating is when juveniles wander within other breeding pairs’ territories. These results suggest that the benefits of delayed dispersal declined with offspring age and with renesting by parents. Third, I observed that survival during the dependent period and first year was greater in slaty antshrikes compared to that of northern hemisphere species. Pre-reproductive survival relative to adult survival was equal or greater than that observed in northern hemisphere species. The date offspring left the nest, mass, and age at dispersal influenced offspring survival, whereas offspring sex and year did not. Relatively high survival during the pre-reproductive period coupled with comparatively low annual productivity clarifies how many tropical species achieve replacement. High juvenile survival appears to obtain from extended post-fledging parental care, delayed dispersal, low costs of dispersal, and a less seasonal environment. Lastly, I experimentally manipulated begging at the nest to examine changes in parental behavior. Under elevated begging, parents increased provisioning rates and reduced the time between arrival to the nest and feeding of nestlings, potentially to reduce begging sounds. Furthermore, parents switched to preferentially feed the closest offspring during the begging treatment. This suggests parents either allowed sibling competition to influence feeding decisions, or feeding the closer nestling increased the efficiency of provisioning. In summary, I found that slaty antshrikes have delayed age at reproduction, higher post-fledging and first year survival, extended post-fledging parental care, equal or greater pre-reproductive survival relative to adult survival, and delayed dispersal compared to many northern hemisphere passerines. These results suggest that this tropical species has a strategy of high investment into few offspring. Furthermore, reproductive effort is equal or greater at least in slaty antshrikes compared to northern hemisphere species, suggesting that the latitudinal gradient in clutch size is not explained by a gradient in reproductive effort.

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Previous research has demonstrated that aggression and marginalization are key components of maintaining popularity within male peer groups. However, more recent ethnographic studies have documented a significant shift in young men’s attitudes and behaviours, with more inclusive masculinities flourishing. My previous research has examined friendship dynamics and popularity hierarchies among boys, showing that contemporary popularity is stratified by a boy’s charisma, authenticity, emotional support, and social fluidity. In this article, I draw upon ethnographic research to provide an intersectional analysis of how adolescent masculinities are influenced by class, age and sexuality

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In diesem Beitrag wird ein neu entwickelter Schülerinnen- und Schülerfragebogen zur Erfassung aggressiver und nicht aggressiver Schülerstörungen, aggressiven Lehrerverhaltens, Störungen des methodisch-didaktischen Settings sowie Klassenführung und Beziehung vorgestellt und die testtheoretischen Kennwerte diskutiert. Die faktorielle Struktur wurde an einer Stichprobe von N=1341 Schülerinnen und Schüler der fünften und sechsten Klasse ermittelt. Eine explorative Faktorenanalyse mit Oblimin-Rotation ergab sieben eindeutige, gut interpretierbare Faktoren, welche den theoretisch postulierten Konstrukten entsprechen. Vier Faktoren erfassen Störungen und drei Faktoren umfassen störungspräventive Merkmale des Unterrichts. Die internen Konsistenzen der Skalen liegen zwischen .60 und .88. (DIPF/Orig.)

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W artykule dowodzi się tezy, że współczesne debaty publiczne, emitowane w telewizji (takie jak emitowany od 2004 roku w TVP2 program Jana Pospieszalskiego „Warto rozmawiać”), są zdarzeniami komunikacyjnymi zasadzonymi na konflikcie destruktywnym, a więc takim, który wg L. Kriesberga, nastawiony jest nie na problem wywołujący frustrację, ale jest manifestacją agresji, a celem sporu staje się nie pokonanie różnic dzielących strony, ale pokonanie oponenta. Wynika to z sytuacji komunikacyjnej debaty telewizyjnej i nastawienia w pierwszej kolejności na zdobycie uwagi, a potem zaspokajanie potrzeb odbiorcy sekundarnego – widza. Podporządkowane są temu takie elementy, jak wybór tematu debaty, jej scenariusz, dobór uczestników, a w dalszej kolejności ich zachowania werbalne i niewerbalne. W rezultacie, w debacie telewizyjnej złamane zostają typowe dla debaty konstruktywnej reguły i strategie, i zastąpione zostają zachowaniami typowymi dla konfliktu destruktywnego, takimi jak: brak otwartości na argumenty drugiej strony, nastawienie na pokonanie antagonisty, niechęć do szukania innych rozwiązań, jak tylko moja wygrana - twoja przegrana, działania nastawione na prowokację i podważanie wiarygodności partnera, przenoszenie ciężaru debaty ze sprawy na osobę, posługiwanie się argumentacją niemerytoryczną, niezgoda na konstruowanie wspólnego stanowiska. Taki wzorzec debaty telewizyjnej, która stała się pośpieszną, bezproduktywną prezentacją rozbieżnych stanowisk, nie prowadzącą do żadnych konkluzji, nastawioną najwyżej na obrażenie rozmówcy i dostarczenie widzowi krótkotrwałych emocji, buduje powszechne przekonania o niemożności dialogu i porozumienia w dyskursie publicznym i dominującym w nim antagonizmie.

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The teleost fish nonapeptides, arginine vasotocin (AVT) and isotocin (IT), have been implicated in the regulation of social behavior. These peptides are expected to be involved in acute and transient changes in social context, in order to be efficient in modulating the expression of social behavior according to changes in the social environment. Here we tested the hypothesis that short-term social interactions are related to changes in the level of both nonapeptides across different brain regions. For this purpose we exposed male zebrafish to two types of social interactions: (1) real opponent interactions, from which a Winner and a Loser emerged; and (2) mirror-elicited interactions, that produced individuals that did not experience a change in social status despite expressing similar levels of aggressive behavior to those of participants in real-opponent fights. Non-interacting individuals were used as a reference group. Each social phenotype (i.e. Winners, Losers, Mirror-fighters) presented a specific brain profile of nonapeptides when compared to the reference group. Moreover, the comparison between the different social phenotypes allowed to address the specific aspects of the interaction (e.g. assessment of opponent aggressive behavior vs. self-assessment of expressed aggressive behavior) that are linked with neuropeptide responses. Overall, agonistic interactions seem to be more associated with the changes in brain AVT than IT, which highlights the preferential role of AVT in the regulation of aggressive behavior already described for other species.

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Mate choice is a primary mechanism driving the evolution of sexually selected traits such as elabo-rate displays and ornaments. In a majority of taxa studied to date, females are seen to actively sampleand evaluate multiple males, presumably to optimize mating opportunities. During this process femalesmay encounter males both familiar and novel, a distinction that might influence how mate choice pro-ceeds. Using a socially monogamous passerine, the blue-black grassquit (Volatinia jacarina), we studiedhow females respond to novel versus familiar (“paired”) males, and how encounters with novel malesinfluence subsequent interactions with their paired males. Additionally, we measured the hormonalresponse of males after visualizing their paired females interacting with novel males. We found thatfemales were attentive to novel males irrespective of these males’ phenotypic attributes, suggesting thatin these interactions novelty is highly relevant. After exposure to novel males, females tended to respondaggressively towards their paired males; by contrast, the behaviour of males towards their paired femalesdid not change. Moreover, we did not detect any hormonal responses of males to viewing their pairedfemales interacting with novel males. Together these results suggest that the distinction between famil-iarity and novelty may hold special relevance for females in mate choice, a finding that bears upon ourunderstanding of the evolution of extra-pair paternity and reproductive behaviour.

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The World Health Organization aims to eradicate wild poliovirus worldwide by the end of 2018. Cameroon and Nigeria, neighboring countries, have been affected by the terrorist and militant activities of the Islamist sect Boko Haram. Impacted regions are mainly the far North of Cameroon and Northern Nigeria. Targets of Boko Haram aggression in these zones include violence against polio workers, disruption of polio immunization campaigns, with consequent reduced access to health care and immunization. In addition to this significant problem, Northern Nigeria has historically seen rejection of polio virus vaccine initiatives. It remains to know how health systems can continue operations against polio in areas where Boko Haram operates. If appropriate measures are not urgently taken, it will be not possible to meet the 2018 goal of polio virus eradication. The response should include specialized immunization activities in conflict zones, will engagement of leaders. Countries should also explore immunization activities by soldiers and military personnel.

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State responses to external threats and aggression are studied with focus on two different rationales: (1) to make credible deterrent threats to avoid being exploited, and (2) to minimize the risk of escalation to unwanted war. Given external aggression, the target state's responding behavior has three possibilities: concession (under-response), reciprocation, and escalation. This study focuses on the first two possibilities and investigates how the strategic nature of crisis interaction can explain the intentional choice of concession or avoidance of retaliation. I build a two-level bargaining model that accounts for the domestic bargaining situation between the leader and the challenger for each state. The model's equilibrium shows that the responding behavior is determined not only by inter-state level variables (e.g. balance of power between two states, or cost of war that each state is supposed to pay), but also the domestic variables of both states. Next, the strategic interaction is rationally explained by the model: as the responding state believes that the initiating state has strong domestic challenges and, hence, the aggression is believed to be initiated for domestic political purposes (a rally-around-the-flag effect), the response tends to decrease. The concession is also predicted if the target state leader has strong bargaining power against her domestic challengers \emph{and} she believes that the initiating leader suffers from weak domestic standing. To test the model's prediction, I conduct a lab experiment and case studies. The experimental result shows that under an incentivized bargaining situation, individual actors are observed to react to hostile action as the model predicts: if the opponent is believed to suffer from internally driven difficulties, the subject will not punish hostile behavior of the other player as severely as she would without such a belief. The experiment also provides supporting evidence for the choice of concession: when the player finds herself in a favorable situation while the other has disadvantages, the player is more likely to make concessions in the controlled dictator game. Two cases are examined to discuss how the model can explain the choice of either reciprocation or concession. From personal interviews and fieldwork in South Korea, I find that South Korea's reciprocating behavior during the 2010 Yeonpyeong Island incident is explained by a combination of `low domestic power of initiating leader (Kim Jong-il)' and `low domestic power of responding leader (Lee Myung-bak).' On the other hand, the case of EC-121 is understood as a non-response or concession outcome. Declassified documents show that Nixon and his key advisors interpreted the attack as a result of North Korea's domestic political instabilities (low domestic power of initiating leader) and that Nixon did not have difficulties at domestic politics during the first few months of his presidency (high domestic power of responding leader).

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Un número considerable de personas mayores padece alguna enfermedad neurodegenerativa que limita sus facultades intelectivas y volitivas, lo que en la práctica suele traducirse en alteraciones de la personalidad con conservación de consciencia, pérdidas de memoria, desorientación, inquietud, confusión o agresividad. Este deterioro progresivo de capacidad que puede afectar a nuestros mayores no sólo los convierte en fácil objetivo de agresiones sino también en potenciales creadores de riesgos y daños a terceros. Es precisamente la responsabilidad que puede derivarse de tales daños la que será analizada en primer lugar en esta sede, exponiendo el estado de la cuestión tanto en el civil como en el common law. Por otro lado, cuando una persona que tiene sus funciones cognitivas mermadas causa un daño a otro, no sólo se debe analizar la responsabilidad civil del propio agente del daño frente al perjudicado, sino también aquélla en que podría incurrir la persona encargada de su cuidado en caso de haberla. Dicha cuestión ocupará la segunda parte del presente trabajo.

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Background: Malnutrition in surgical patients is associated with delayed recovery, higher rates of morbidity and mortality, prolonged hospital stay, increased healthcare costs and a higher early re-admission rate. Methods: Data synthesis after review of pertinent literature. Results: The aetiology of malnutrition is multifactorial. In cancer patients, there is an abnormal peripheral glucose disposal, gluconeogenesis, and whole-body glucose turnover. Malnourished cancer patients undergoing major operations are at significant risk from perioperative complications such as infectious complications. Surgical aggression generates an inflammatory response which worsens intermediary metabolism. Conclusions: Nutritional evaluation and nutritional support must be performed in all surgical patients, in order to minimize infectious complications. Enteral nutrition early in the postoperative period is effective and well tolerated reducing infectious complications, improving wound healing and reducing length of hospital stay. Pharmaconutrition is indicated in those patients, who benefit from enteral administration of arginine, omega 3 and RNA, as well as parenteral glutamine supplementation. When proximal sutures are used, tubes allowing early jejunal feeding should be used.

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Aggression is a complex behavior that influences social relationships and can be seen as adaptive or maladaptive depending on the context and intensity of expression. A model organism suitable for genetic dissection of the underlying neural mechanisms of aggressive behavior is still needed. Zebrafish has already proven to be a powerful vertebrate model organism for the study of normal and pathological brain function. Despite the fact that zebrafish is a gregarious species that forms shoals, when allowed to interact in pairs, both males and females express aggressive behavior and establish dominance hierarchies. Here, we describe two protocols that can be used to quantify aggressive behavior in zebrafish, using two different paradigms: (1) staged fights between real opponents and (2) mirror-elicited fights. We also discuss the methodology for the behavior analysis, the expected results for both paradigms, and the advantages and disadvantages of each paradigm in face of the specific goals of the study.

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Dissertação de Mestrado apresentada ao Instituto Superior de Psicologia Aplicada para obtenção de grau de Mestre na especialidade de Psicologia Clínica.

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Dissertação (mestrado)—Universidade de Brasília, Instituto de Psicologia, Departamento de Psicologia Social e do Trabalho, Programa de Pós Graduação em Psicologia Social, do Trabalho e das Organizações, 2016.

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Alcohol is one of the oldest and most widely used drugs on the planet, but the cellular mechanisms by which it affects neural function are still poorly understood. Unlike other drugs of abuse, alcohol has no specific receptor in the nervous system, but is believed to operate through GABAergic and serotonergic neurotransmitter systems. Invertebrate models offer circuits of reduced numerical complexity and involve the same cell types and neurotransmitter systems as vertebrate circuits. The well-understood neural circuits controlling crayfish escape behavior offer neurons that are modulated by GABAergic inhibition, thus making tail-flip circuitry an effective circuit model to study the cellular mechanisms of acute alcohol exposure. Crayfish are capable of two stereotyped, reflexive escape behaviors known as tail-flips that are controlled by two different pairs of giant interneurons, the lateral giants (LG) and the medial giants (MG). The LG circuit has been an established model in the neuroscience field for more than 60 years and is almost completely mapped out. In contrast, the MG is still poorly understood, but has important behavioral implications in social behavior and value-based decision making. In this dissertation, I show that both crayfish tail-flip circuitry are physiologically sensitive to relevant alcohol concentrations and that this sensitivity is observable on the single cell level. I also show that this ethyl alcohol (EtOH) sensitivity in the LG can be changed by altering the crayfish’s recent social experience and by removing descending inputs to the LG. While the MG exhibits similar physiological sensitivity, its inhibitory properties have never been studied before this research. Through the use of electrophysiological and pharmacological techniques, I show that the MG exhibits many similar inhibitory properties as the LG that appear to be the result of GABA-mediated chloride currents. Finally, I present evidence that the EtOH-induced changes in the MG are blocked through pre-treatment of the potent GABAA receptor agonist, muscimol, which underlines the role of GABA in EtOH’s effects on crayfish tail-flip circuitry. The work presented here opens the way for crayfish tail-flip circuitry to be used as an effective model for EtOH’s acute effects on aggression and value-based decision making.

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La ansiedad constituye un factor de riesgo para el bienestar y el desarrollo personal, social y académico de niños y adolescentes. Altos niveles de ansiedad reducen la eficiencia en el aprendizaje, ya que disminuyen la atención, la concentración y la retención, con el consecuente deterioro en el rendimiento escolar. Las investigaciones muestran altas tasas de prevalencia de ansiedad en población adolescente, especialmente en las mujeres. El objetivo del estudio es analizar la ansiedad escolar en una muestra de adolescentes chilenos según género y edad. Participaron 673 adolescentes, estudiantes de 6 colegios de la provincia de Ñuble, cuyo rango de edad es de 13 a 17 años (M = 15, 26; DE = 1, 32). La Ansiedad Escolar se evaluó con el Inventario de Ansiedad Escolar (IAES) que evalúa tres sistemas de respuesta; ansiedad cognitiva, ansiedad conductual y ansiedad psicofisiológica, y tres factores situacionales: ansiedad ante la evaluación social, ansiedad ante el fracaso escolar, y ansiedad ante la agresión. Los hombres presentaron puntuaciones menores que las mujeres, siendo las diferencias estadísticamente significativas en todos los sistemas de respuesta y en todos los factores situacionales. En los grupos de edad, las diferencias significativas se presentaron en el sistema de respuesta cognitivo, en dos factores situacionales (ansiedad ante el fracaso escolar y ansiedad ante la agresión) y en la puntuación total. El grupo de varones de 17 años fue quien presentó menores niveles de ansiedad escolar.