894 resultados para Agonistic behaviors
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Pós-graduação em Aquicultura - FCAV
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Among the species of freshwater shrimp being cultivated, Macrobrachium rosenbergii stands out. Knowledge about the behavior of this species and the influence of certain factors on its development can help optimize management practices and minimize the likely impacts shrimp farming has on the environment and the animals themselves. The objective of this study was to characterize the species' behavior during early stages of development under different stocking densities over a 24-hour cycle. Ten day old postlarvae were transferred from the Jundiaí School of Agriculture (EAJ - Escola Agrícola de Jundiaí) in Macaíba (RN), Brazil to the Shrimp Behavior Laboratory (LSPR - Laboratório de Estudos do Comportamento do Camarão) at the Federal University of Rio Grande do Norte (UFRN), where they were weighed and measured. Eight aquaria with constant temperature, aeration and filtration, and subjected to a12 h light/12 h dark cycle were used for each experiment. Each aquarium also contained two shelters made of bricks and the water quality was monitored weekly. Behavioral observations were made at two densities: 25 individuals/m-² and 40 individuals/m-². The methods for recording behaviors were: behavioral sampling – enter and leave the shelter, exploring on the substrate, exploring in the water column, move away, attack, pursuit and cannibalism; scan sampling - inactivity, feeding, exploration, digging, swimming, cleaning and staying in the shelter. Observations were made during a 15 minute period/per aquarium at a frequency of 4 times daily, for 4 days/week, and over 4 weeks. Food was provided 2 times/day for each aquarium population, immediately before the 1st and 3rd observation periods. Our results demonstrate that at high density, there is an increased frequency of agonistic behavior; during the light phase, there is a greater frequency of behaviors that result in less exposure (inactivity, cleaning and staying in the shelter); during the dark phase, there is an increased frequency of behaviors that result in greater exposure (feeding, exploration, swimming and digging); at times of feed offer, there is an increased frequency of leaving the shelter, moving away, pursuit, feeding, exploration and swimming. At low density, the animals showed a lower frequency of agonistic behaviors, greater weight gain and higher growth rates, which indicates that this is a more favorable growing environment for cultivation and when applied, can generate better living conditions, favor survival rates and increase management success
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Understanding how genes affect behavior is critical to develop precise therapies for human behavioral disorders. The ability to investigate the relationship between genes and behavior has been greatly advanced over the last few decades due to progress in gene-targeting technology. Recently, the Tet gene family was discovered and implicated in epigenetic modification of DNA methylation by converting 5-methylcytosine to 5-hydroxymethylcytosine (5hmC). 5hmC and its catalysts, the TET proteins, are highly abundant in the postnatal brain but with unclear functions. To investigate their neural functions, we generated new lines of Tet1 and Tet3 mutant mice using a gene targeting approach. We designed both mutations to cause a frameshift by deleting the largest coding exon of Tet1 (Tet1Δe4) and the catalytic domain of Tet3 (Tet3Δe7-9). As Tet1 is also highly expressed in embryonic stem cells (ESCs), we generated Tet1 homozygous deleted ESCs through sequential targeting to compare the function of Tet1 in the brain to its role in ESCs. To test our hypothesis that TET proteins epigenetically regulate transcription of key neural genes important for normal brain function, we examined transcriptional and epigenetic differences in the Tet1Δe4 mouse brain. The oxytocin receptor (OXTR), a neural gene implicated in social behaviors, is suggested to be epigenetically regulated by an unknown mechanism. Interestingly, several human studies have found associations between OXTR DNA hypermethylation and a wide spectrum of behavioral traits and neuropsychiatric disorders including autism spectrum disorders. Here we report the first evidence for an epigenetic mechanism of Oxtr transcription as expression of Oxtr is reduced in the brains of Tet1Δe4-/- mice. Likewise, the CpG island overlapping the promoter of Oxtr is hypermethylated during early embryonic development and persists into adulthood. We also discovered altered histone modifications at the hypermethylated regions, indicating the loss of TET1 has broad effects on the chromatin structure at Oxtr. Unexpectedly, we discovered an array of novel mRNA isoforms of Oxtr that are selectively reduced in Tet1Δe4-/- mice. Additionally, Tet1Δe4-/- mice display increased agonistic behaviors and impaired maternal care and short-term memory. Our findings support a novel role for TET1 in regulating Oxtr expression by preventing DNA hypermethylation and implicate TET1 in social behaviors, offering novel insight into Oxtr epigenetic regulation and its role in neuropsychiatric disorders.
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Algumas pesquisas demonstram que a presença de um parceiro social durante uma situação de risco modula a resposta ao estresse, atenuando seus efeitos negativos. Neste estudo, 8 díades de machos e 8 de fêmeas de sagüi comum (Callithrix jacchus) foram expostos a um ambiente novo, sozinhos e acompanhados de um parceiro de mesmo sexo e idade. Quando submetidos a um ambiente novo em companhia de um animal de mesmo sexo, os machos apresentaram um perfil mais filiativo enquanto as fêmeas foram mais competitivas entre si. Os resultados mostram que a resposta comportamental é sexualmente dimórfica, e que machos e fêmeas utilizam diferentes estratégias quando confrontados com situações desafiadoras no ambiente natural Abstract Some researches demonstrate that the presence of a social partner during a challenging situation modulates the stress response, decreasing its negative effects. In this study common marmoset (Callithrix jacchus) males and females were exposed to a new environment, alone or in companion of a social partner of the same sex and age. When submitted to new environment in companion of a same-sex social partner males showed more affiliation whereas females performed agonistic behaviors. The results show that behavioral response is sexually dimorphic and that males and females used different strategies when facing challenging situations in natural conditions
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Dominance status among female marmosets is reflected in agonistic behavior and ovarian function. Socially dominant females receive submissive behavior from subordinates, while exhibiting normal ovulatory function. Subordinate females, however, receive agonistic behavior from dominants, while exhibiting reduced or absent ovulatory function. Such disparity in female fertility is not absolute, and groups with two breeding females have been described. The data reported here were obtained from 8 female-female pairs of captive female marmosets, each housed with a single unrelated male. Pairs were classified into two groups: “uncontested” dominance (UD) and “contested” dominance (CD), with 4 pairs each. Dominant females in UD pairs showed significantly higher frequencies (4.1) of agonism (piloerection, attack and chasing) than their subordinates (0.36), and agonistic behaviors were overall more frequently displayed by CD than by UD pairs. Subordinates in CD pairs exhibited more agonistic behavior (2.9) than subordinates in UD pairs (0.36), which displayed significantly more submissive (6.97) behaviors than their dominants (0.35). The data suggest that there is more than one kind of dominance relationship between female common marmosets. Assessment of progesterone levels showed that while subordinates in UD pairs appeared to be anovulatory, the degree of ovulatory disruption in subordinates of CD pairs was more varied and less complete. We suggest that such variation in female-female social dominance relationships and the associated variation in the degree and reliability of fertility suppression may explain variations of the reproductive condition of free-living groups of common marmosets
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Algumas pesquisas demonstram que a presença de um parceiro social durante uma situação de risco modula a resposta ao estresse, atenuando seus efeitos negativos. Neste estudo, 8 díades de machos e 8 de fêmeas de sagüi comum (Callithrix jacchus) foram expostos a um ambiente novo, sozinhos e acompanhados de um parceiro de mesmo sexo e idade. Quando submetidos a um ambiente novo em companhia de um animal de mesmo sexo, os machos apresentaram um perfil mais filiativo enquanto as fêmeas foram mais competitivas entre si. Os resultados mostram que a resposta comportamental é sexualmente dimórfica, e que machos e fêmeas utilizam diferentes estratégias quando confrontados com situações desafiadoras no ambiente natural Abstract Some researches demonstrate that the presence of a social partner during a challenging situation modulates the stress response, decreasing its negative effects. In this study common marmoset (Callithrix jacchus) males and females were exposed to a new environment, alone or in companion of a social partner of the same sex and age. When submitted to new environment in companion of a same-sex social partner males showed more affiliation whereas females performed agonistic behaviors. The results show that behavioral response is sexually dimorphic and that males and females used different strategies when facing challenging situations in natural conditions
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Dominance status among female marmosets is reflected in agonistic behavior and ovarian function. Socially dominant females receive submissive behavior from subordinates, while exhibiting normal ovulatory function. Subordinate females, however, receive agonistic behavior from dominants, while exhibiting reduced or absent ovulatory function. Such disparity in female fertility is not absolute, and groups with two breeding females have been described. The data reported here were obtained from 8 female-female pairs of captive female marmosets, each housed with a single unrelated male. Pairs were classified into two groups: “uncontested” dominance (UD) and “contested” dominance (CD), with 4 pairs each. Dominant females in UD pairs showed significantly higher frequencies (4.1) of agonism (piloerection, attack and chasing) than their subordinates (0.36), and agonistic behaviors were overall more frequently displayed by CD than by UD pairs. Subordinates in CD pairs exhibited more agonistic behavior (2.9) than subordinates in UD pairs (0.36), which displayed significantly more submissive (6.97) behaviors than their dominants (0.35). The data suggest that there is more than one kind of dominance relationship between female common marmosets. Assessment of progesterone levels showed that while subordinates in UD pairs appeared to be anovulatory, the degree of ovulatory disruption in subordinates of CD pairs was more varied and less complete. We suggest that such variation in female-female social dominance relationships and the associated variation in the degree and reliability of fertility suppression may explain variations of the reproductive condition of free-living groups of common marmosets
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Animals show behavioral and physiological changes that emerge in response to environmental perturbations (i.e., emergency life-history stages). In this study, we investigate the effects of light intensity on aggressive encounters and social stability in groups of adult male Nile tilapia, Oreochromis niloticus (Linnaeus, 1758). The study compared the behavior observed under low (280.75 ± 50.60 lx) and high (1394.14 ± 520.32 lx) light intensities, with 12 replicates for each treatment. Adult fish were isolated in 36-L aquaria for 96 hours, and three males were grouped for 11 days in 140-L aquaria. Agonistic behavior was video-recorded (10 min/day) on the 3rd, 5th, 7th, and 9th day to quantify aggressive interactions and social stability. There was an effect of light intensity and day of observation on the total number of agonistic behaviors performed by the fish group. Besides, increased frequency of aggressive interactions (the sum of the four sessions) by the alpha, beta and gamma fish occurred at the higher light intensity. The dominance ranks of the fish remained unchanged across the observation sessions under both the low and high light intensities. We concluded that enhanced light intensity has a cumulative effect that increases the aggressiveness of the Nile tilapia but that this effect is not sufficiently strong to destabilize the social hierarchy.
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Abstract Invasive species represent with fragmentation of habitat the most serious threats to biodiversity in the world. Galápagos Archipelago, as most oceanic islands, suffers a high rate of introduced animals and plants that affect equilibrium and biodiversity of this unique biota. Ants rank among the most devastating invaders. Their social organization confer them a high ability to adapt and to spread in new environments forming rapidly populous communities. We studied the ant community of Floreana Island composed mainly of introduced species (at least 1 S). Introduction events occurred successively during last century. The last record is Monomorium destructor arrived in the eighties. Our aim is to investigate the modalities of interaction and coexistence of these introduced species. We highlighted the competition hierarchy of the coexisting species using attractive food baits. Two species behave as competitively dominant by monopolizing an important part of resources. They are M. destructor restricted to a small area and the fire ant Solenopsis geminata widely distributed on the island. Then we evaluated the relative importance of abiotic factors and interspecific competition in structuring the community. Ecological data were collected and presence and abundance of species were estimated using different methods in a wide range of habitats. Several species showed preferences either for arid or for humid areas. The little fire ant Wasmannia auropunctata, awell-known devastating species when introduced, was exclusively found in moist habitat in and around the agricultural area situated in the upper and central part of thé island. It coexists with other species in several parts but in a restricted perimeter it excludes all other ants and worker's density on the ground is nearly 70 times higher than ant's density in similar habitats occupied by several species. But most opportunist tramp species establish everywhere without particular ecological requirement. Analyses of species co-occurrences at various levels didn't reveal any marked effect of competition in structuring ant's assemblages. We supposed that the lack ofcompetition-derived structure has to be attributed to the dynamic of the system. Indeed, across the successive census of 1996, 2003, 2004 and 2005, species distributions and abundances appeared to be highly variables. In particular harsh conditions occurring in dry season in certain parts seem to be limiting to S. geminatai. We suggest that huge variations in the local distribution of the dominant S. geminata disrupt the community organization. Finally we conducted artificial ant confrontations to evaluate to what extend an aggressive behavior at the worker level maybe linked to the ecological success of a species on the island. S. geminata was rather indifferent when confronted to a submissive species on food sources, suggesting that its competitive dominance is largely due to a numerical superiority. On the other hand M. destructor exhibits a strong agonistic behavior in similar confrontations. As soon as the presence of a competitor is detected, most workers were observed to abandon foraging and to take part in physical aggressions. Since it is still restricted nearby its introduction spot two decades after its arrival, we suggest that the energetic cost of such an aggressive behavior prevent it to spread on that island already highly colonized. Dominant invasive species such as the fire ants S. geminata and W. auropunctata have negative impacts on Galápagos fauna, disturbing the hatching of land tortoises and birds. But very little is known about the impact of other exotic ants. Indeed, impact on arthropods and generally on ground-dwelling organisms is very diffcult to evaluate. As a consequence of the dynamic character of Floreana I. ant community it is difficult to build models or to málce predictions on evolution of introduced ant fauna. But Camponotus macilentus, an abundant endemic species seems today to be little affected by introduced ant species thanks to its strong interference competition ability and its preference for arid and harsh environments. Résumé Les espèces envahissantes représentent, avec la fragmentation du paysage, la plus grande menace pour la biodiversité. L'archipel des Galápagos, comme la plupart des îles du Pacifique, compte un grand nombre d'espèces introduites qui menacent la biodiversité de ce milieu unique.. Les fourmis sont parmi les envahisseurs les plus dévastateurs. Leur organisation sociale leur permet de s'adapter et de se propager pour devenir rapidement abondantes. Nous avons étudié la communauté de fourmis sur l'île de Floreana principalement composée d'espèces introduites (au moins 15). Les introductions se sont succédées au cours du siècle précédent. La dernière espèce recensée est Monomorium destructor introduite dans les années 80. Notre objectif est de mettre à jour les modalités des interactions et de la coexistence de ces espèces introduites. Nous avons mis en évidence la hiérarchie de compétition des différentes espèces à l'aide d'appâts de nourriture. Deux espèces se comportent de façon dominante en monopolisant une part importante des ressources. Ce sont M. destructor, restreintes à un petit périmètre, et la fourmi de feu Solenopsis geminata, largement distribuée sur l'île. Nous avons évalué l'importance relative des facteurs abiotiques et de la compétition interspécifique dans la structuration des peuplements. Des données écologiques ont été collectées et la présence et l'abondance des espèces ont été estimées à l'aide de trois méthodes au sein d'une grande diversité d'habitats. Plusieurs espèces .montrent des préférences soit pour les milieux humides, soit pour les milieux arides. La petite fourmi de feu Wasmannia auropunctata, une espèce connue pour être dévastatrice dans ses sites d'introduction, est présente exclusivement dans les habitats humides dans et à proximité de la zone agricole située dans la partie centrale de l'île. Elle coexiste en plusieurs points avec d'autres espèces mais au sein d'un périmètre restreint elle exclut toute autre fourmi et atteint des densités record au sol presque 70 fois supérieures aux densités de fourmis observées sur les sites voisins occupés par plusieurs espèces. Mais la plupart des espèces vagabondes opportunistes s'établissent partout sans exigences écologiques particulières. Des analyses de cooccurrence d'espèces à plusieurs niveaux n'ont pas révélé de rôle marqué de la compétition dans la structuration des communautés. Nous supposons que l'absence d'une telle structure doit être attribuée à la dynamique du système. En effet, au cours des différents recensements de 1996-1997, 2003, 2004 et 2005, la distribution et l'abondance des espèces était très variable. En particulier, les conditions rudes qui règnent dans la zone aride durant la saison sèche semblent affecter particulièrement S. geminata. Nous suggérons que de fortes variations dans la distribution de l'espèce dominante perturbent l'orgaiùsation des communautés. Finalement nous avons effectué des confrontations artificielles pour évaluer dans quelle mesure un comportement agressif au niveau de l'ouvrière peut être lié au succès écologique d'une espèce sur l'île. S. geminata montre très peu de réaction face à une espèce subordonnée sur une même source de nourriture, ce qui laisse supposer que sa dominance est largement due à sa supériorité numérique. Par contre, dans des conditions similaires, M. destructor est fortement agressive. En présence d'un compétiteur, la plupart des ouvrières renoncent très vite à leur activité de fourragement pour agresser les individus de l'autre espèce. Puisque deux décennies après son introduction elle est toujours confinée à son point d'arrivée, nous supposons que le coût en énergie et en ouvrières de ce comportement très agressif est un obstacle à son expansion sur cette île déjà fortement colonisée. Les espèces envahissantes dominantes comme les fourmis de feu S. geminata et W. auropunctata sont connues pour leur impact négatif sur la faune des Galápagos, entre autre sur les jeunes des tortues terrestres et des oiseaux. Mais nous savons très peu de choses sur l'impact des autres espèces de fourmis introduites. En effet, l'impact sur les arthropodes, et plus généralement sur la faune du sol, est très difficile à évaluer. En raison du caractère dynamique de la communauté de fourmi de Floreana, il est difficile de construire des modèles et de faire des prédictions sur l'évolution des peuplements de fourmis introduites. Mais Camponotus macilentus, une espèce endémique abondante, semble aujourd'hui peu affectée par les espèces introduites grâce à ses capacités de compétition par interférence et sa préférence pour les milieux arides. Resumen Las, especies invasoras representan, junto con la fragmentación del paisaje, la mayor amenaza para la biodiversidad. El archipiélago de Galápagos, como la mayoría de las islas del Pacífico, cuenta con un gran número de especies introducidas que amenazan la biodiversidad de este lugar único. Las hormigas son uno de los invasores más devastadores. Su organización social les permite adaptarse y propagarse para ser rápidamente abundante. Estudiamos la comunidad de hormigas de la isla Floreana principalmente compuesta de especies introducidas (al menos 15). Las introducciones se sucedieron durante el siglo anterior. La última especie contabilizada es Monomorium destructor introducida en los años 80. Nuestro objetivo es poner al día las modalidades de las interacciones y de la coexistencia de estas especies introducidas. Pusimos de relieve la jerarquía de competencia de las distintas especies con ayuda de cebos de comida. Dos especies se implican de manera dominante monopolizando una parte importante de los recursos. Son M. destructor, limitado a un pequeño perímetro, y la hormiga de fuego Solenopsis geminata; ampliamente distribuida por la isla. Evaluamos la importancia relativa de los factores abióticos y de la competencia interespecífica en la estructuración de la communidad. Se recogieron algunos datos ecológicos y se consideraron la presencia y la abundancia de las especies con ayuda de tres métodos en una gran diversidad de hábitats. Varias especies muestran preferencias o por los medios húmedos, o por los medios áridos. La pequeña hormiga de fuego Wasmannia auropunctata, una especie conocida por ser devastadora en sus lugares de introducción, está presente exclusivamente en los hábitats húmedos y cerca de la zona agrícola situada en la parte central de la isla. Coexiste en varios puntos con otras especies pero en un perímetro limitado excluye a cualquier otra hormiga y alcanza densidades en el suelo casi 70 veces superiores a las densidades de hormigas observadas en los lugares vecinos ocupados por varias especies. Pero la mayoría de las especies vagabundas oportunistas se establecen por todas partes sin exigencias ecológicas particulares. Análisis de cooccurrencía de las especies a varios niveles no revelaron una grande importancía de la competencia en la estructuración de las comunidades. Suponemos que la ausencia de tal estructura Bebé ser por la dinámica del sistema. Efectivamente, durante los distintos censos de 1996-1997, 2003,.2004 y 2005, la distribución ? la abundancia de las especies eran muy variables. En particular, las condiciones drásticas que reinan en la zona árida durante la temporada seca parecen afectar especialmente a S. geminata. Sugerimos que fuertes variaciones en la distribución de la especie dominante perturben la organización de las comunidades. Finalmente efectuamos confrontaciones artificiales para evaluar hastá que punto un comportamiento agresivo a nivel de la obrera puede explicar el éxito ecológico de una especie en la isla. S. geminata muestra muy poca reacción ante una especie subordinada mientras comparten la misma comida, lo que deja suponer que su dominancia se debe a su superioridad numérica. Por el contrario, en condiciones similares, M. destructor es muy agresivo. En presencia de otra especie, la mayóría de las obreras renuncian muy rápidamente a alimentarse para atacar a los individuos de la otra especie. Puesto que dos décadas después de su introducción todavía se confina en su punto de llegada, suponemos que el coste en energía y en obreras de este comportamiento muy agresivo es un obstáculo a su extensión en esta isla ya muy colonizada. Las especiés invasoras dominantes como las hormigas de fuego S. geminata y W. auropunctata son conocidas por su impacto negativo en la fauna de Galápagos, entre otras cosas sobre los juveniles de las tortugas terrestres y pájaros. Pero sabemos muy poco sobre el impacto de las otras especies de hormigas introducidas. Efectivamente es muy difïcil de evaluar el impacto en los artrópodos, y más generalmente en la fauna del suelo. Debido al carácter dinámico de la comunidad de hormiga de Floreana, es diEcil construir modelos y hacer predicciones sobre la evolución de las poblaciones de hormigas introducidas. Pero Camponotus macilentus, una especie endémica abundante, parece poco afectadá hoy por las especies introducidas gracias a sus capacidades de competencia por interferencia y su preferencia por los medios áridos.
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In this study, a questionnaire was applied to patients from Ribeirão Preto Dental School, University of São Paulo, Brazil, to evaluate the hygiene methods and habits concerning the use of complete dentures, the age of dentures, and whether patients have been instructed on how to clean their dentures. The mean age of patients was 63.35 years, and most of them were females (82.08%). The results showed that 62.26% of the respondents had been using the same maxillary complete denture for more than 5 years, and 49.06% used the same mandible complete denture for more than 5 years. Of the patients interviewed, 58.49% slept with the dentures. Mechanical brushing was the most used cleaning method by the patients (100%), using water, dentifrice and toothbrush (84.91%). Most patients (51.89%) reported never having been instructed by their dentists as to how to clean their dentures. Based on the limitations of this study, it was concluded that the patients interviewed had limited knowledge about prosthetic hygiene and oral care. The method more used by patients was the mechanical method of brushing, most patients used the same complete dentures for more than 5 years and slept with the dentures.
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It is well established that morphine inhibits maternal behaviors. Previous studies by our group have shown activation of the rostrolateral periaqueductal gray (rlPAG) upon inhibition-intended subcutaneous injections of morphine. In this context, we demonstrated that a single naloxone infusion into the rlPAG, following this opioid-induced inhibition, reactivated maternal behaviors. Since these data were obtained by using peripheral morphine injections, the present study was designed to test whether morphine injected directly into the rlPAG would affect maternal behaviors. Our hypothesis that morphine acting through the rlPAG would disrupt maternal behaviors was confirmed with a local infusion of morphine. The mothers showed shorter latency for locomotor behavior to explore the home cage (P = 0.049). Inhibition was especially evident regarding retrieving (P = 0.002), nest building (P = 0.05) and full maternal behavior (P = 0.023). These results support the view that opioidergic transmission plays a behaviorally meaningful inhibitory role in the rostrolateral PAG.
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During a four month scholarly leave in United States of America, researchers designed a culturally appropriate prevention program for eating disorders (ED) for Brazilian adolescent girls. The program "Se Liga na Nutrição" was modeled on other effective programs identified in a research literature review and was carried out over eleven interactive sessions. It was positively received by the adolescents who suggested that it be part of school curricula. The girls reported that it helped them to develop critical thinking skills with regards to sociocultural norms about body image, food and eating practices