997 resultados para defense behavior


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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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The study was carried out at the UNESP Rio Claro campus (SP), where biotests consisting of simulated ant attacks were performed in colonies of Mischocyttarus cerberus. The behaviors of the wasps were recorded with a camcorder, for further analysis. This analysis was done using the Mann-Whitney U test and the Principal Component Analysis. In the pre-emergence development stage, colonies with a single foundress defend the nest only after the first larvae appear. When there are only eggs in the nest, the wasp abandons the nest. Before leaving, the wasp rubs its gaster against the nest, releasing the ant repellent secretion. When the nest contains larvae or larvae and pupae, the foundress defends the colony, vibrating its wings, pumping her abdomen and biting the ant.

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The coreid Leptoglossus zonatus (Dallas, 1852) is commonly found in corn (Zea mays L.) fields in Brazil, and it has been observed flying and landing on objects or persons near these fields. During January, 1995, this behavior was studied in corn plantations. Results indicated that the bugs concentrated on objects (plastic cylinders traps) introduced into their habitat and that their number increased during the first 24 hs. However, as time passed (8 days), this possible territorial or recognition behavior gradually decreased, and tended to disappear.

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The behavioral effects of trans-(±)-1-amino-1,3-cyclopentanedicarboxylic acid (t-ACPD), a metabotropic glutamate receptor (mGluR) agonist, or 0.9% (w/v) saline, injected into the dorsal periaqueductal gray (DPAG), was investigated. Male Wistar rats showed defense reactions characterized by jumps toward the top edges of the cages (saline = 0 vs t-ACPD = 6.0, medians P<0.05) and gallops (saline = 0 vs t-ACPD = 10.0, medians P<0.05) during the 60-s period after the beginning of the injection. In another experiment animals were placed inside an open arena for 5 min immediately after injection. Their behavior was recorded by a video camera and a computer program analyzed the videotapes. Eleven of fifteen rats injected with t-ACPD showed a short-lasting (about 1 min) flight reaction. No saline-treated animal showed this reaction (P<0.0005, chi-square test). The drug induced an increase in turning behavior (P = 0.002, MANOVA) and a decrease in the number of rearings (P<0.001, MANOVA) and grooming episodes (P<0.001, MANOVA). These results suggest that mGluRs play a role in the control of defense reactions in the DPAG.

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The amygdala, the dorsal periaqueductal gray (dPAG), and the media] hypothalamus have long been recognized to be a neural system responsible for the generation and elaboration of unconditioned fear in the brain. It is also well known that this neural substrate is under a tonic inhibitory control exerted by GABA mechanisms. However, whereas there is a growing body of evidence to suggest that the amygdala and dPAG are also able to integrate conditioned fear, it is still unclear, however, how the distinct hypothalamic nuclei participate in fear conditioning. In this work we aimed to examine the extent to which the gabaergic mechanisms of this brain region are involved in conditioned fear using the fear-potentiated startle (FPS). Muscimol, a GABA-A receptor agonist, and semicarbazide, an inhibitor of the GABA synthesizing enzyme glutamic acid decarboxylase (GAD), were used as an enhancer and inhibitor of the GABA mechanisms, respectively. Muscimol and semicarbazide were injected into the anterior hypothalamus (AHN). the dorsomedial part of the ventromedial nucleus (VMHDM), the dorsomedial (DMH) or the dorsal premammillary (PMD) nuclei of male Wistar rats before test sessions of the fear conditioning paradigm. The injections into the DMH and PMD did not produce any significant effects on FPS. On the other hand, muscimol injections into the AHN and VMHDM caused significant reduction in FPS. These results indicate that injections of muscimol and semicarbazide into the DMH and PMD fail to change the FPS, whereas the enhancement of the GABA transmission in the AHN and VMHDM produces a reduction of the conditioned fear responses. On the other hand, the inhibition of this transmission led to an increase of this conditioned response in the AHN. Thus, whereas DMH and PMD are known to be part of the caudal-most region of the medial hypothalamic defensive system, which integrates unconditioned fear, systems mediating conditioned fear select the AHN and VMHDM nuclei that belong to the rostral-most portion of the hypothalamic defense area. Thus, distinct subsets of neurons in the hypothalamus could mediate different aspects of the defensive responses. (C) 2008 Elsevier Inc. All rights reserved.

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Tutkimuksen kohteena on yksi sotilasyksikkö, Reserviupseerikoulun Esikunta- ja viestikomppania. Kyseisessä yksikössä koulutetaan reservinupseereita sotilaspo-liisi-, huolto-, johtamisjärjestelmä- ja komentopaikkatehtäviin. Sotilaspoliisilinja ja huoltolinja ovat liittyneet yksikköön vuoden 2014 lopulla. Tämä integraatio on saanut aikaan tiedonintressin koulutuslinjojen kulttuureihin liittyen. Tarkoituksena on selvittää miten linjojen koulutuskulttuurit poikkeavat toisistaan ja mitä kulttuurien integraatiossa tapahtuu. Tutkimuksen tavoitteena on myös antaa suosituksia yksikölle mahdollisten kulttuuriristiriitojen ja konfliktien hallitsemiseksi. Tutkimus on luonteeltaan sosiaaliantropologista kauppatieteellistä kulttuurintutki-musta. Taustatieteinä ovat liiketaloustiede, antropologia, sosiologia ja osittain or-ganisaatiopsykologia. Tutkimusote on laadullinen ja aineiston hankinnan mene-telminä on käytetty yksikön kouluttajien haastatteluja ja osallistuvaa havainnointia. Tutkimusaineisto on analysoitu teoriaohjaavaa laadullista sisällönanalyysiä käyttäen. Analyysin tavoitteena oli tunnistaa erot integroituvissa koulutuskulttuureissa, ymmärtää eroista johtuvien konfliktien logiikkaa ja tarkastella kulttuurien vuotamisen logiikkaa. Esikunta- ja viestikomppanian koulutuskulttuurien erilaisuutta analysoitiin seuraavien teoriateemojen kautta: oppilaskäsitys, suhtautuminen upseerioppilaisiin, artefaktit (koulutusmenetelmät), arvot, asenteet ja kouluttamisen syväoletukset. Koulutuskulttuurien kohtaamista analysoitiin psykologisen omistajuuden, reviirikäyttäytymisen ja kulttuurin vuotamisen teorioiden kautta. Tutkimustulokset osoittavat, että kulttuurilla todella on merkitystä sotilasorganisaa-tion integraatiotilanteessa. Esikunta- ja viestikomppanian koulutuskulttuureissa on havaittavissa huomattavia eroja, mutta myös samankaltaisuuksia. Kulttuurien erot johtavat ristiriitaisuuksiin, konflikteihin, reviirikäyttäytymiseen ja saavat ihmiset osoittamaan mieltään eri tavoin. Toisaalta kulttuuripiirteillä on myös taipumusta vuotaa ympäristöön nopeuttaen uusien organisaation osien sopeutumista. Johtajan rooli kulttuurien hallinnassa on keskeinen. Johtajan oma kulttuuriorientaatio voi johtaa konflikteihin, mutta toisaalta myös ratkaista niitä. Tärkeimpänä johtopäätöksenä on, että suuressa sotilasyksikössä kannattaisi laatia strategia eli suunnitelma kulttuurin johtamista varten silloin, kun integraatio on tapahtumassa. Strategian avulla voidaan ottaa kantaa useisiin kulttuurillisiin ristiriitoihin, joita siis Esikunta- ja viestikomppaniankin tapauksessa ilmenee. Koko yksikön henkilöstä kannattaisi sitouttaa ja ottaa mukaan strategian laadintaan. Strategia selventäisi esimerkiksi yksikön arvoja, visiota, missiota, tehtäviä, erilaisten linjojen erityisasemaa ja poikkeuksia, haluttua ja toivottua toimintaa ja asennetta, palkitsemiskäytäntöjä, toisin sanoen kulttuurin eri tekijöitä. Strategia ei ole vain liiketaloudellinen tulosyksikön pitkän tähtäimen pakollinen työkalu, vaan myös sotilasorganisaation kulttuurin johtamisen väline.

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Anurans are known to feign death as a way to avoid or minimize the risk of predation. However, information on this defensive strategy is scattered and we believe that there is more than one behaviour type referred to as thanatosis. Here we review the literature, add original data, and propose definitions and new names that complement the present knowledge on the subject. We collected information on 334 individuals of 99 species in 16 families and grouped the recorded displays into two categories of tonic immobility: (1) thanatosis, death-feigning, or playing possum, and (2) shrinking or contracting. These two categories are treated as different behaviour types because of the display pattern (position of fore- and hindlimbs, eye opening), presence of skin toxins (shrinking is mostly displayed by toxic species, whereas thanatosis is mostly displayed by non-toxic species), social context (interaction with predators), and their putative or actual functions. © 2010 Taylor & Francis.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The troglobitic armored catfish, Ancistrus cryptophthalmus (Loricariidae, Ancistrinae) is known from four caves in the São Domingos karst area, upper rio Tocantins basin, Central Brazil. These populations differ in general body shape and degree of reduction of eyes and of pigmentation. The small Passa Três population (around 1,000 individuals) presents the most reduced eyes, which are not externally visible in adults. A small group of Passa Três catfish, one male and three females, reproduced spontaneously thrice in laboratory, at the end of summertime in 2000, 2003 and 2004. Herein we describe the reproductive behavior during the 2003 event, as well as the early development of the 2003 and 2004 offsprings, with focus on body growth and ontogenetic regression of eyes. The parental care by the male, which includes defense of the rock shelter where the egg clutch is laid, cleaning and oxygenation of eggs, is typical of many loricariids. On the other hand, the slow development, including delayed eye degeneration, low body growth rates and high estimated longevity (15 years or more) are characteristic of precocial, or K-selected, life cycles. In the absence of comparable data for close epigean relatives (Ancistrus spp.), it is not possible to establish whether these features are an autapomorphic specialization of the troglobitic A. cryptophthalmus or a plesiomorphic trait already present in the epigean ancestor, possibly favoring the adoption of the life in the food-poor cave environment. We briefly discuss the current hypotheses on eye regression in troglobitic vertebrates.

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Neonate Lepidoptera are confronted with the daunting task of establishing themselves on a food plant. The factors relevant to this process need to be considered at spatial and temporal scales relevant to the larva and not the investigator. Neonates have to cope with an array of plant surface characters as well as internal characters once the integument is ruptured. These characters, as well as microclimatic conditions, vary within and between plant modules and interact with larval feeding requirements, strongly affecting movement behavior, which may be extensive even for such small organisms. In addition to these factors, there is an array of predators, pathogens, and parasitoids with which first instars must contend. Not surprisingly, mortality in neonates is high but can vary widely. Experimental and manipulative studies, as well as detailed observations of the animal, are vital if the subtle interaction of factors responsible for this high and variable mortality are to be understood. These studies are essential for an understanding of theories linking female oviposition behavior with larval survival, plant defense theory, and population dynamics, as well as modern crop resistance breeding programs.

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This paper seeks to investigate the effectiveness of sea-defense structures in preventing/reducing the tsunami overtopping as well as evaluating the resulting tsunami impact at El Jadida, Morocco. Different tsunami wave conditions are generated by considering various earthquake scenarios of magnitudes ranging from M-w = 8.0 to M-w = 8.6. These scenarios represent the main active earthquake faults in the SW Iberia margin and are consistent with two past events that generated tsunamis along the Atlantic coast of Morocco. The behavior of incident tsunami waves when interacting with coastal infrastructures is analyzed on the basis of numerical simulations of near-shore tsunami waves' propagation. Tsunami impact at the affected site is assessed through computing inundation and current velocity using a high-resolution digital terrain model that incorporates bathymetric, topographic and coastal structures data. Results, in terms of near-shore tsunami propagation snapshots, waves' interaction with coastal barriers, and spatial distributions of flow depths and speeds, are presented and discussed in light of what was observed during the 2011 Tohoku-oki tsunami. Predicted results show different levels of impact that different tsunami wave conditions could generate in the region. Existing coastal barriers around the El Jadida harbour succeeded in reflecting relatively small waves generated by some scenarios, but failed in preventing the overtopping caused by waves from others. Considering the scenario highly impacting the El Jadida coast, significant inundations are computed at the sandy beach and unprotected areas. The modeled dramatic tsunami impact in the region shows the need for additional tsunami standards not only for sea-defense structures but also for the coastal dwellings and houses to provide potential in-place evacuation.

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A ideação paranoide é um processo cognitivo e social que pode ser considerado normativo (e.g. sentimentos de desconfiança ocasionais) ou disfuncional, constituindo-se, neste ultimo caso, como um sintoma psicopatológico (e.g. delírios paranoides). Mesmo em níveis subclínicos, a ideação paranoide pode constituir um entrave para o bom funcionamento interpessoal, na medida em que o comportamento disruptivo que dela advém pode afetar todas as esferas de funcionamento do indivíduo (e.g. relações familiares, entre pares, profissionais e/ou académicas). O presente estudo explorará a influência dos estilos parentais e o papel mediador da ideação paranoide na agressividade durante a adolescência, bem como as implicações para a prevenção e intervenção em contextos clínicos e educacionais.

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Biomphalaria glabrata can react through different pathways to Schistosoma mansoni miracidium penetration, according to the degree of resistance/susceptibility presented by different snail strains, which is a genetically determined character, resistance being the dominant feature. However, it has been observed that previous susceptible snail strain may change its reactive behavior along the course of infection, exhibiting later a pattern of cercarial shedding and histopatopathological picture compatible with high resistance. Such observation suggests the possibility of B. glabrata to develop a sort of adaptative immunity face a schistosome infection. To explore on this aspect, the present investigation looked for the behavior of S. mansoni infection in B. glabrata previously subjected to different means of artificial stimulation of its internal defense system. Snails previously inoculated with irradiated miracídia (Group I); treated with S. mansoni antigens (Group II) or with a non-related parasite antigen (Group III) were challenged with 20 viable S. mansoni miracidia, and later looked for cercarial shedding and histopathologic changes at different times from exposition. Nodules of hemocyte accumulations were found at the site of antigen injection. These nodules resembled solid granulomas, and were larger and more frequent in snails injected with S. mansoni products as compared to those injected with Capillaria hepatica. However, the presence of such granulomas did not avoid the S. mansoni challenge infection from developing in a similar way as that seen in controls. The data are indicative that hemocytes are able to proliferate locally when stimulated, such capacity also remaining localized, not being shared by the population of hemocytes located elsewhere within the snail body.

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Attempts over the past 50 years to explain variation in the abundance, distribution and diversity of plant secondary compounds gave rise to theories of plant defense. Remarkably, few phylogenetically robust tests of these long-standing theories have been conducted. Using >50 species of milkweed (Asclepias spp.), we show that variation among plant species in the induction of toxic cardenolides is explained by latitude, with higher inducibility evolving more frequently at lower latitudes. We also found that: (1) the production of cardenolides showed positive-correlated evolution with the diversity of cardenolides, (2) greater cardenolide investment by a species is accompanied by an increase in an estimate of toxicity (measured as chemical polarity) and (3) instead of trading off, constitutive and induced cardenolides were positively correlated. Analyses of root and shoot cardenolides showed concordant patterns. Thus, milkweed species from lower latitudes are better defended with higher inducibility, greater diversity and added toxicity of cardenolides.