953 resultados para aggressive behavior


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This research was developed in the center-urban area at the city of Dourados (MS), in Tibouchina granulosa trees, a plant popularly known as quaresmeira in Brazil. The floral visitors of this species were recorded in three daily periods: 7 - 8 a.m., 1 - 2 p.m. and 4 - 5 p. m. Bee visitors of those plants were collected with an entomological net when they landed on the flowers. The bees were anesthetized in a closed camera containing etila acetate, conserved in Dietrich ' s fixative and, soon afterwards, transferred to 70% ethyl alcohol for subsequent identification. Almost 300 specimens of Africanized Apis mellifera, Trigona spinipes and Tetragonisca angustula were collected. The presence of these three species of bees in the flowers of T. granulosa suggests that they can be considered the main floral visitors of that vegetal species. T. angustula workers did not visit the flowers of T. granulosa between 7 and 8 a.m., but they were the main floral visitors from 4 to 5 p.m. The workers of T. spinipes presented a very aggressive behavior against the Africanized A. mellifera workers on the quaresmeira flowers, defending the food sources with strength and efficiency and provoking a drastic reduction in the number of honeybee visits between 1 and 2 p.m. Nevertheless, they did not interfere in the opportunistic activity of foraging by T. angustula workers, mainly between 4 and 5 p.m. The most important result of this research was the detection of the Competitive Exclusion Principle between A. mellifera and T. spinipes species in relation to the foraging behavior, when they exploit the floral resources of T. granulosa.

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The aggressive behavior of ants that protect plants from herbivores in exchange for rewards such as shelter or food is thought to be an important form of biotic defense against herbivory, particularly in tropical systems. To date, however, no one has compared the defensive responses of different ant taxa associated with the same plant species, and attempted to relate these differences to longer-term efficacy of ant defense. We used experimental cues associated with herbivory-physical damage and extracts of chemical volatiles from leaf tissue-to compare the aggressive responses of two ant species obligately associated with the Amazonian myrmecophyte Tococa bullifera (Melastomataceae). We also conducted a colony removal experiment to quantify the level of resistance from herbivores provided to plants by each ant species. Our experiments demonstrate that some cues eliciting a strong response from one ant species elicited no response by the other. For cues that do elicit responses, the magnitude of these responses can vary interspecifically. These patterns were consistent with the level of resistance provided from herbivores to plants. The colony removal experiment showed that both ant species defend plants from herbivores: however, herbivory was higher on plants colonized by the less aggressive ant species. Our results add to the growing body of literature indicating defensive ant responses are stimulated by cues associated with herbivory. However, they also suggest the local and regional variation in the composition of potential partner taxa could influence the ecology and evolution of defensive mutualisms in ways that have previously remained unexplored.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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O futebol possui grande representatividade social em diferentes culturas. Porém, a paixão despertada nas torcidas pode gerar comportamentos agressivos e violentos, em um momento que deveria ser de diversão, caracterizando o lazer desviante, o qual ainda não está devidamente esclarecido. Esta pesquisa qualitativa teve como objetivo investigar, nos estudos acadêmicos, o comportamento agressivo das torcidas organizadas e seus desdobramentos no tempo destinado ao lazer. Para tanto, na pesquisa bibliográfica, buscou-se informações em obras de referência, compostas por livros e teses, além da consulta a diferentes bases de dados, com os descritores: lazer, torcidas organizadas, agressividade e violência. Os resultados indicam que, independente da gênese do comportamento agressivo, quando em presença de um grupo, ou dependendo do contexto sociohistórico, da composição das torcidas, da violência integrante da sociedade, da mídia, da má organização esportiva e da impunidade, estes fatores podem afetar mudança no comportamento individual, contribuindo para manifestações agressivas e violentas no âmbito futebolístico em campo e nas torcidas. Este tipo de manifestação pode favorecer a diminuição do público nos estádios, além de repercutir na delimitação das atividades vivenciadas no contexto do lazer. Estas condutas violentas podem, até mesmo, acarretar graves conseqüências nos âmbitos físico e/ou psíquico. Por fim, aponta-se a premência de políticas públicas específicas envolvendo o lazer e os megaeventos.

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Social behavior of Hypsiboas albomarginatus was studied in the Atlantic rain forest, Municipality of Ubatuba, in the north coast of the State of São Paulo, southeastern Brazil. Vocalizations of H. albomarginatus are described, including contexts in which they were emitted and temporal and spectral parameters differentiating advertisement from aggressive calls. Dominant call frequency was inversely correlated with male length and body mass but not with environmental temperature. Number of pulses per note was not correlated with any variable, and advertisement call amplitude was influenced by temperature and time. During chorus aggregation, males interacted acoustically by emitting advertisement calls in antiphony, or by emitting aggressive calls. Some disputes among males culminated in physical combat; males performed kicks and slaps on rivals' heads, in an apparent attempt to dislodge rivals from perches. Visual signals were also displayed during conflicts between males, contributing to an escalation of aggressive behavior. Visual signals were not recorded during courtship between males and females but may help in the accurate localization of the signaling male during aggressive interactions.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Constrictotermes rupestris, new species, is described from central Brazil, with illustrations of the imago, soldier, worker head, worker mandibles, worker mandibular gland, and nest. The new species lives in a dry forest, on rocky terrain, building its nest always on rocks. In the colonies examined, all castes showed a striking reddish coloration due to something accumulated in the fat tissues. Inquilinitermes microcerus was present in most examined nests. The worker of C. rupestris has an enlarged mandibular gland. Workers also show an aggressive behavior, which suggests that the mandibular glands may produce defensive secretions.

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The action of São Paulo's Italian reformist socialists at the beginning of the 20th century had a political impact on the way of considering the question of democracy both in the state of São Paulo and the whole of Brazil. In fact not only did the socialists oppose the fascist political project and the symbolic roots of its aggressive behavior, but they also faced the opposition of the theoretical proposals coming from other leftist groups. This article intends to present the main interlocutors of these socialists and understand how this theoretical dispute has developed.

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Introduction. Osteosarcomas are highly malignant bone-forming neoplasms that account for about 20% of all sarcomas. In light of their aggressive behavior, early diagnosis is crucial for determining adequate treatment. Dental professionals may be the first to detect jaw osteosarcomas in their initial stages. The aim of this case report is to draw attention to the possibility of diagnosing this tumor based on clinical, radiographical and cytological characteristics before confirmation by histology. Case presentation. A 24-year-old Afro-Brazilian man presented with swelling and pain on the left side of the mandible in the region of the third molar (tooth 38). Radiography showed a poorly delimited intraosseous lesion with radiolucent and radiopaque areas. The cytological aspects were consistent with the diagnosis of osteosarcoma, which was confirmed by biopsy. Conclusion. Imprint cytology was found to be a reliable, rapid and easy complementary examination. An early diagnosis of osteosarcoma of the jaw is fundamental to the early determination of an adequate treatment. © 2009 Cabral et al; licensee BioMed Central Ltd.

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Introduction. Granular cell tumor is an uncommon neoplasm that can occur in any part of the body, including the orofacial region. The tumor is usually benign, but there are reports of cases in which the tumor shows a locally aggressive behavior, malignancy, and distant metastases. The most widely accepted hypothesis is that granular cell tumor arises from the altered metabolism of Schwann cells. The tumor is typically asymptomatic and appears as a nodule that does not exceed 3 cm. Case presentation. In case 1, a 26-year-old Caucasian man was seen at the Oral Medicine out-patient clinic of the São José dos Campos Dental School, Universidade Estadual Paulista, with a 'small blister on the tongue', which he had noted approximately three years ago. The nodule was located on the dorsum of the tongue, measured about 1.5 cm in diameter, and was not tender to palpation. Treatment consisted of an excisional biopsy performed on the basis of the diagnostic hypothesis of granular cell tumor, which was confirmed by microscopic analysis. In case 2, a 31-year-old Caucasian woman attended the out-patient clinic of the São José dos Campos Dental School, Universidade Estadual Paulista, with a five-year history of a 'painful lump on the tongue'. Intra-oral examination revealed the presence of a nodular lesion measuring approximately 0.8 cm in diameter, which was located deep in the submucosa of the right lateral margin of the tongue. Treatment consisted of an excisional biopsy performed on the basis of the differential diagnosis of neurofibroma and granular cell tumor. Microscopic analysis defined the final diagnosis of granular cell tumor. Conclusions: Granular cell tumor is an uncommon tumor that must be carefully diagnosed and treated correctly. © 2012 Sena Costa et al; licensee BioMed Central Ltd.

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Environmental enrichment seeks to improve the behavior of captive animals. Few studies have developed enrichment strategies for fish, particularly for use in aquaculture. Environmental enrichment for territorial and aggressive animals has the potential to increase both the amount of defensible resources and the value of a disputed territory which can increase the level of aggression. This study evaluated this hypothesis for the redbreast tilapia, Tilapia rendaIli. We used a short-term approach for evaluation of fish aggressive behavior by recording it for 30 min after introduction of a pair of fish into each experimental aquarium. Our main finding was that the latency to start a fight was lower in an enriched environment, but the frequency of attacks was higher in a non-enriched environment (control). Furthermore, we observed clear hierarchical behavior (submissive dark stripes on the body and dominant light-colored bodies without stripes) only in the non-enriched environment. Structural enrichment of the environment for redbreast tilapia leads to decreased aggression and cohabitation without hierarchical dominance. © 2013 Copyright Taylor and Francis Group, LLC.

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Pós-graduação em Biologia Geral e Aplicada - IBB

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)