Prior residence and body size influence interactions between black sea urchins

Body size and prior residence can modulate agonistic interaction in several animal species, but scientists know little about these relationships in echinoderms. In this study, we tested the effects of these traits on interactions in the black sea urchin (Echinometra lucunter). After a sea urchin was isolated for 24-h in a glass tank to establish prior residence, we introduced an intruder animal adjacent to the resident in the tank and observed interactions for 30 min. The intruder animal was larger, smaller, or size-matched to the resident. We found body size and prior residence concomitantly modulated interactions among black sea urchins, with prior residence as the major determinant. Black sea urchins mainly exhibited opponent inspection and fleeing responses during interaction to avoid fights, especially when a fight could be seriously disadvantageous (small intruder vs. large resident). (C) 2008 Elsevier B.V. All rights reserved.

Early social environment and the fighting behaviour of young Oreochromis niloticus (Pisces, Cichlidae)

This study examines the influence of early experience with different forms of aggressive behaviour on the fighting behaviour of young fish. Fry of the cichlid fish, Oreochromis niloticus, were raised from hatching in small groups consisting of a normal individual (the test fish) and either mutant conspecifics lacking the dorsal fin and thereby the ability to perform fin displays, or normal ones. Following a 63-day period of development in groups the test fish were confronted in their home tanks with an unfamiliar normal fish for 10 min. The fighting behaviour of the test fish was analyzed considering their previous group type (mutant or normal) and rank (alpha or beta). There was no difference between test fish in the rate and sequence of behaviour patterns used in fighting. However, test fish that had developed in mutant groups were rarely the first to bite in contests and had a longer latency to biting following the first bite of the stimulus fish than rest fish with normal experience. This finding is attributable to the form of aggressive behaviour experienced by the test fish during development but not to existing differences in the amount of aggression previously experienced, nor to previous rank, sex, or size relative to the stimulus fish. The results suggest that early experience influenced decision making by the test fish during the fight. The involvement of the fin displays and the possible mechanism of this influence are discussed.

Stress responses of the fish Nile tilapia subjected to electroshock and social stressors

Plasma cortisol and glucose levels were measured in 36 adult Nile tilapia males, Oreochromis niloticus (standard length, mean ± SD, 14.38 ± 1.31 cm), subjected to electroshock and social stressors. Pre-stressor levels were determined 5 days after the adjustment of the fish to the experimental aquaria (1 fish/aquarium). Five days later, the effects of stressors on both cortisol and glucose levels were assessed. The following stressors were imposed for 60 min: pairing with a larger resident animal (social stressor), or a gentle electroshock (AC, 20 V, 15 mA, 100 Hz for 1 min every 4 min). Each stressor was tested in two independent groups, one in which stress was quantified immediately after the end of the 60-min stressor imposition (T60) and the other in which stress was quantified 30 min later (T90). Pre-stressor values for cortisol and glucose were not statistically different between groups. Plasma cortisol levels increased significantly and were of similar magnitude for both electroshock and the social stressor (mean ± SD for basal and final samples were: electroshock T60 = 65.47 ± 15.3, 177.0 ± 30.3; T90 = 54.8 ± 16.0, 196.2 ± 57.8; social stress T60 = 47.1 ± 9.0, 187.6 ± 61.7; T90 = 41.6 ± 8.1, 112.3 ± 26.8, respectively). Plasma glucose levels increased significantly for electroshock at both time points (T60 and T90), but only at T90 for the social stressor. Initial and final mean (± SD) values are: electroshock T60 = 52.5 ± 9.2, 115.0 ± 15.7; T90 = 35.5 ± 1.1, 146.3 ± 13.3; social stress T60 = 54.8 ± 8.8, 84.4 ± 15.0; T90 = 34.5 ± 5.6, 116.3 ± 13.6, respectively. Therefore, electroshock induced an increase in glucose more rapidly than did the social stressor. Furthermore, a significant positive correlation between cortisol and glucose was detected only at T90 for the social stressor. These results indicate that a fish species responds differently to different stressors, thus suggesting specificity of fish stress response to a stressor.

Eye color as an indicator of social rank in the fish Nile tilapia

We investigated the association of eye color with the dominant-subordinate relationship in the fish Nile tilapia, Oreochromis niloticus. Eye color pattern was also examined in relation to the intensity of attacks. We paired 20 size-matched fish (intruder: 73.69 ± 11.49 g; resident: 75.42 ± 8.83 g) and evaluated eye color and fights. These fish were isolated in individual aquaria for 10 days and then their eye color was measured 5 min before pairing (basal values). Twenty minutes after pairing, eye color and fights were quantified for 10 min. Clear establishment of social hierarchy was observed in 7 of 10 pairs of fish. Number of attacks ranged from 1 to 168 among pairs. The quartile was calculated for these data and the pairs were then divided into two classes: low-attack (1 to 111 attacks - 2 lower quartiles) or high-attack (112 to 168 attacks - 2 higher quartiles). Dominance decreased the eye-darkening patterns of the fish after pairing, while subordinance increased darkening compared to dominance. Subordinate fish in low-attack confrontations presented a darker eye compared to dominant fish and to the basal condition. We also observed a paler eye pattern in dominants that shared low-attack interactions after pairing compared to the subordinates and within the group. However, we found no differences in the darkening pattern between dominants and subordinates from the high-attack groups. We conclude that eye color is associated with social rank in this species. Moreover, the association between eye color and social rank in the low-attack pairs may function to reduce aggression.

Oxidative stress biomarkers and aggressive behavior in fish exposed to aquatic cadmium contamination

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The aggressive behavior of Nile tilapia introduced into novel environments with variation in enrichment

Many studies show environmental enrichment is correlated with benefits to captive animals; however, one should not always assume this positive relationship given that enrichment increases the amount of resources that a territorial animal must defend and possibly affects its aggressive dynamics. In this study, we tested if environmental enrichment affects aggressive interactions in the aggressive fish Nile tilapia (Oreochromis niloticus). We compared fights staged between pairs of male tilapia of similar size (= matched in resource holding potential) in a novel arena that was either barren or enriched, to examine whether enrichment enhances territory value in line with theoretical predictions, with the potential for compromised welfare. We evaluated time elapsed until the first attack (latency), frequency of aggressive interactions and fight duration. We detected fight dynamic differences at the pair level. Higher resource value generated increased aggression but had no effect on fight duration or latency. This conclusion is in line with game theory predictions concerning resource value and contradicts the theory that enrichment of the environment will serve welfare purposes. (C) 2010 Elsevier GmbH. All rights reserved.

Aggressive Behavior and Performance in the Tegu Lizard Tupinambis merianae

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fight versus flight: the interaction of temperature and body size determines antipredator behaviour in tegu lizards

Ectotherm antipredator behaviour might be strongly affected both by body temperature and size: when environmental temperatures do not favour maximal locomotor performance, large individuals may confront predators, whereas small animals may flee, simply because they have no other option. However, integration of body size and temperature effects is rarely approached in the study of antipredator behaviour in vertebrate ectotherms. In the present study we investigated whether temperature affects antipredator responses of tegu lizards, Tupinambis merianae, with distinct body sizes, testing the hypothesis that small tegus (juveniles) run away from predators regardless of the environmental temperature, because defensive aggression may not be an effective predator deterrent, whereas adults, which are larger, use aggressive defence at low temperatures, when running performance might be suboptimal. We recorded responses of juvenile (small) and adult (large) tegu lizards to a simulated predatory attack at five environmental temperatures in the laboratory. Most differences between the two size classes were observed at low temperatures: large tegus were more aggressive overall than were small tegus at all temperatures tested, but at lower temperatures, the small lizards often used escape responses whereas the large ones either adopted a defensive posture or remained inactive. These results provide strong evidence that body size and temperature affect the antipredator responses of vertebrate ectotherms. We discuss the complex and intricate network of evolutionary and ecological parameters that are likely to be involved in the evolution of such interactions. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Percurso e resultados da terapia fonoaudiológica na síndrome de Prader-Willi (SPW): relato de caso

O objetivo deste estudo foi descrever o percurso e os resultados da terapia fonoaudiológica na síndrome de Prader-Willi, por meio do estudo longitudinal do caso de uma criança de 8 anos de idade, do gênero masculino, ao longo de quatro anos de terapia fonoaudiológica em uma clínica-escola. Foram realizadas filmagens de sessões de terapia e análise documental de informações dos prontuários referentes à anamnese, avaliação e relatórios terapêuticos fonoaudiológicos e avaliações multidisciplinares. A criança apresentou características típicas da síndrome de Prader-Willi como obesidade, hiperfagia, ansiedade, problemas de comportamento e auto-agressões. em avaliação fonoaudiológica foram observados hipotonia orofacial, sialorréia, voz hipernasal, alterações cognitivas, dificuldades de compreensão oral, comunicação por meio de gestos e produção de palavras isoladas ininteligíveis. Inicialmente, a terapia fonoaudiológica teve o objetivo principal de promover o desenvolvimento da linguagem com ênfase na interação social por meio de atividades lúdicas. Com a evolução do caso o direcionamento principal passou a ser o desenvolvimento de habilidades conversacionais e narrativas. Foram observadas evoluções quanto à manutenção da atenção, brincadeira simbólica, contato social e comportamento. Além disso, houve aumento do vocabulário, evolução quanto à compreensão oral e desenvolvimento de habilidades narrativas. Dessa maneira, a intervenção fonoaudiológica em caso de síndrome de Prader-Willi foi eficaz em diferentes níveis, no que se refere às habilidades fonológicas, sintáticas, lexicais e pragmáticas da linguagem

Comportamento intra-específico do cupim Heterotermes tenuis (Hagen) (Isoptera, Rhinotermitidae) em condições de laboratório

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Violência, sociedade e escola: da recusa do diálogo à falência da palavra

Esse artigo aborda a violência na sociedade capitalista e na escola, permitindo uma discussão sobre como ela é veiculada pelos meios de comunicação e pela maneira como os professores a enfrentam. Enfoca a necessidade da comunicação e aponta as dificuldades vivenciadas na construção do indivíduo, do aluno em particular, quando a escola e o professor não possuem clareza da importância da comunicação como forma de simbolização e representação que, em muitos casos, permitem que os atos violentos possam ser substituídos pela palavra. A escola é um lugar privilegiado para a palavra e denúncia de um problema social. Ao se desejar eliminar a violência, acaba-se por naturalizá-la, através das banalizações sofridas pelos meios de comunicação e de um Estado que legitima e violenta seus cidadãos em seus direitos básicos.

Programa de apoio a cuidadores: uma ação terapêutica e preventiva na atenção à saúde dos idosos

Dans le cadre du service de gériatrie du Centre de Santé-école de la faculté de médecine de Botucatu (Université de São Paulo), a été établi un programme d'appui à ces soignants avec les objectifs suivants: préserver leur qualité de vie et favoriser de meilleures conditions familiales aux patients. Le programme comprend de 10 à 12 réunions par semaine, de deux heures de durée, coordonnées par deux psychologues. on utilise des techniques de psychodrame centrées sur le rôle du soignant et leurs conséquences sociales et émotionnelles. Les informations théoriques sont transmises au moyen de discussions de groupe et de moyens audiovisuels. Les thèmes suivants sont abordés : signification et motivation du soin donné, signaux d'alertes de fatigue physique et mentale du soignant, les possibilités de se traiter et de demander de l'aide, une méthode d'amélioration de la communication face à une déficience visuelle, auditive et cognitive, une méthode pour favoriser l'indépendance et l'autonomie et surmonter les problèmes relatifs à l'hygiène, la mobilité, l'agression, l'irritation, les hallucinations et les idées délirantes de la personne âgée. Au cours de la première réunion de chaque groupe (qui comprend de 10 à 20 participants) on applique une échelle d'évaluation de l'impact émotionnel sur les soignants (Zarit et al., 1980) et le SRQ (Self Report Questionnaire - Mari and Williams, 1986) qui identifient des désordres psychiatriques. Ces échelles sont reproduites à la fin du programme, pour observer d'éventuelles modifications. Les données obtenues indiquent des changements favorables dans l'expression d'émotions, l'établissement de limites et de retour à des activités de loisirs.

Effects of trophic poisoning with methylmercury on the appetitive elements of the agonistic sequence in fighting-fish (Betta splendens)

The aggressive display in Betta splendens is particularly prominent, and vital to its adaptation to the environment. Methylmercury is an organic variation of Hg that presents particularly pronounced neuro-behavioral effects. The present experiments aim to test the effect of acute and chronic poisoning with methylmercury on the display in Bettas. The animals were poisoned by trophic means in both experiments (16 ug/kg in acute poisoning; 16 ug/kg/day for chronic poisoning), and tested in agonistic pairs. The total frequency of the display was recorded, analyzing the topography of the agonistic response. The methylmercury seems to present a dose- and detoxification-dependent effect on these responses, with a more pronounced effect on motivity in acute poisoning and on emotionality in the chronic poisoning. It is possible that this effect could be mediated by alteration in the mono-amino-oxidase systems.

Occurrence of severe and moderate traumatic brain injury in patients attended in a Brazilian teaching hospital - Epidemiology and dosage of alcoholemy

This study aimed at observing aspects of epidemiology in order to investigate the use of alcohol in patients older than 18 with severe and moderate traumatic brain injury, which were attended in the Clinics Hospital of the University of Uberlandia. Positive alcoholemy was found in 39.3% of the patients. of the 33 positive exams alcoholemy was found higher than 60 mg/dL in 28 (84.6%). There was not significant relation between alcoholemy levels and trauma severity. The major prevalence occurred on Saturdays nights. The most frequent types of external causes were transportation accidents (64.74) followed by accidental falls (17.27%) and physical aggression (16.55%). 93.9% of the patients with positive alcoholemy were men aged 20-29. 24.2% of the ones with positive alcoholemy died yet no significant difference was found in the study of the ones with negative alcoholemy (n=51) (p=0.93); RR= 0.9; IC95%=0.40-2.08.

Cadmium and exposure to stress increase aggressive behavior

Environmental toxicants and stress influence the health and behavior of people from different parts of the world. In the present study, aggressive behavior was evaluated in rats exposed to cadmium (Cd) for four weeks and subjected to immobilization stress (IS) based on the resident/intruder paradigm. Latency to the first bite (LB), total number of attacks (NA), total duration of attack manifestations (DAM), and a composite aggression score (CAS) were used to assess aggressiveness. Cadmium concentrations in the blood and the brain were determined. We observed that the parameters of aggressiveness were not altered by either Cd or IS when administered separately. However, animals exposed to Cd + IS had increased NA, DAM, and CAS. Cadmium was detected in the blood and the brain after treatment and Cd + IS exposure modified Cd distribution in these tissues. These results suggest that exposure to low levels of Cd associated with stress may lead to increased aggressiveness in rats. (C) 2011 Elsevier B.V. All rights reserved.