Medroxyprogesterone acetate or long-acting progesterone in the biostimulation of lambs

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The effect of increased light intensity on the aggressive behavior of the Nile tilapia, Oreochromis niloticus (Teleostei: Cichlidae)

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.

Social separation and diazepam withdrawal increase anxiety in the elevated plus-maze and serotonin turnover in the median raphe and hippocampus

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

Low voltage four-quadrant current multiplier: an improved topology for n-well CMOS process

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Social support and infant malnutrition: a case-control study in an urban area of Southeastern Brazil

The relationship between malnutrition and social support was first suggested in the mid-1990s. Despite its plausibility, no empirical studies aimed at obtaining evidence of this association could be located. The goal of the present study was to investigate such evidence. A case-control study was carried out including 101 malnourished children (weight-for-age National Center for Health Statistics/WHO 5th percentile) aged 12-23 months, who were compared with 200 well-nourished children with regard to exposure to a series of factors related to their social support system. Univariate and multiple logistic regressions were carried out, odds ratios being adjusted for per capita family income, mother's schooling, and number of children. The presence of an interaction between income and social support variables was also tested. Absence of a partner living with the mother increased risk of malnutrition (odds ratio 2.4 (95 % CI 1.19, 4.89)), even after adjustment for per capita family income, mother's schooling, and number of children. The lack of economic support during adverse situations accounted for a very high risk of malnutrition (odds ratio 10.1 (95 % CI 3.48, 29.13)) among low-income children, but had no effect on children of higher-income families. Results indicate that receiving economic support is an efficient risk modulator for malnutrition among low-income children. In addition, it was shown that the absence of a partner living with the mother is an important risk factor for malnutrition, with an effect independent from per capita family income, mother's schooling, and number of children.

Evaluating feeding as unconditioned stimulus for conditioning of an endocrine effect in Nile tilapia

This study tested the adequacy of feeding as an unconditioned stimulus (US) to condition an endocrine response (plasma cortisol increase) in the cichlid fish Nile tilapia (Oreochromis niloticus). In a first study, conditioning was confirmed in grouped fish in the only experiment using single-held Nile tilapia. In this test a conditioned stimulus (CS - aeration off) was associated with a stressor (air emersion for 2 min - US). We then assessed whether several events of paired CS-US resulted in a conditioned endocrine response (CR), in this case an increase in plasma cortisol after presentation of the CS only. Before testing feeding as US, the postprandial or social holding condition for feeding effects on cortisol levels was tested. Nile tilapia showed increased cortisol after feeding associated to social context (grouped fish), but not to food only (single-held fish). In a third study, feeding was tested as US in an experiment similar to the first study but an increase in feeding-induced cortisol could not be conditioned. The absence of CR suggests that the stressor affects acquisition of this response, which may be a consequence of stimulus intensity or biological relevance. This study expands the recently reported Pavlovian conditioning paradigm for endocrine response in fish. (C) 2007 Elsevier B.V. All rights reserved.

Chronic social stress in rainbow trout: Does it promote physiological habituation?

The effect of chronic social stress on growth, energetic substrates and hormones was tested in rainbow trout, Oncorhynchus mykiss. After a 14-day isolation period, the fish were paired for 8 days. In order to expose fish to chronic intermittent social contact during pairing, they were maintained in direct contact with each other during the first day. After that, a black plastic screen partition was introduced in each tank, preventing direct contact between animals. Every day the partition was removed for 30 min, allowing physical interaction between fish. At the end of pairing period, they were isolated again for 13 days. Fish were weighed and blood was sampled frequently during the experiment. Plasma levels of cortisol, growth hormone, glucose, total protein and free amino acids were quantified. Both dominants and subordinates had specific growth rate decreased during the pairing period, but only subordinates increased when the stressor was abolished (dominants: 0.32 +/- 0.21 and 0.24 +/- 0.41, subordinates: -0.77 +/- 0.29 and 0.37 +/- 0.31, respectively). Dominants showed a higher cortisol level one week after pairing condition had been abolished than subordinates (dominants: 56.76 +/- 13.26, subordinates: 31.89 +/- 13.36). We conclude that chronic condition of intermittent social stress represents a stressful condition for animals of both hierarchical ranks and a treatment of one daily short direct contact between conspecifics does not promote habituation in fish, as mentioned for other stressors. (C) 2007 Elsevier B.V. All rights reserved.

Influence of Prey Size on the Capture of Social Wasps (Hymenoptera: Vespidae) by the Orb-Web Spider Nephilengys cruentata

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The effect of acidic residues and amphipathicity on the lytic activities of mastoparan peptides studied by fluorescence and CD spectroscopy

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

Effect of water renewal on dominance hierarchy of juvenile Nile tilapia

RECAW - CNPq

Social isolation and aggressiveness in the Amazonian juvenile fish Astronotus ocellatus

Testamos o efeito do isolamento social sobre a agressividade no peixe amazônico, Astronotus ocellatus. Dez peixes juvenis foram transferidos de um aquário de agrupamento (60 x 60 x 40 cm) contendo 15 indivíduos (sem discriminação de sexo) para um aquário de isolamento (50 x 40 x 40 cm). A agressividade foi testada por meio de ataques e exibições direcionadas à imagem do peixe no espelho. O comportamento foi filmado durante 10 min em 4 momentos: 30 min, 1 dia, 5 dias e 15 dias após o isolamento. Nós analisamos a motivação agressiva por meio da latência para início do comportamento agonístico e pela freqüência dos ataques totais e específicos direcionados ao espelho. A latência para o comportamento agonístico reduziu ao longo do isolamento e houve uma tendência de aumento da freqüência de mouth fighting (um ataque de alta intensidade de agressão), mostrando-nos um aumento na motivação agressiva. Os resultados estão de acordo com os encontrados para ciclídeos juvenís de Haplochromis burtoni, mas discordam com os encontrados para Pterophylum scalare (acará bandeira). Sugerimos que o aumento da agressividade em A. ocellatus pode ser mediado pelo efeito de exposição prévia, da residência prévia ou por processos envolvendo reconhecimento de co-específicos.

Effect of caries preventive measures directed to expectant mothers on caries experience in their children

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

Effect of orthognathic surgery for class III correction on quality of life as measured by SF-36

The purpose of this work was to evaluate the quality of life of patients with Angle's class III malocclusion submitted to orthognathic surgery. Twenty-nine patients of both sexes, ranging in age from 17 to 46 years, with Angle's class III malocclusion and indication for surgical treatment, were evaluated about 30 days before surgery and 6 months postoperatively. Surgery consisted of maxillary advancement or mandibular retrusion, or both. The generic SF-36 questionnaire was used to evaluate the following eight domains: functional capacity, physical aspects, pain, general health status, mental health, emotional aspects, social aspects and vitality. Descriptive and inferential statistical analyses were used to determine possible interactions between timing of evaluation, gender and type of surgery. With respect to physical and social aspects, a significant difference in outcomes was observed, with mean scores being higher after surgery regardless of gender or type of surgery. Regarding emotional aspects, an interaction effect was observed for timing and gender, with higher mean scores only being obtained for females after Surgery. Orthognathic Surgery had a positive impact on the quality of life of both male and female patients, improving physical and social aspects, and on that of female patients, improving emotional aspects.

Representação social e estereótipo: a zona muda das representações sociais

Neste artigo, a partir da definição do conceito de zona muda das representações sociais, descrevemos as técnicas de substituição e de descontextualização normativa desenvolvidas pela Escola de Aix-en-Provence para revelar as representações escondidas ou mascaradas em função de sua inadequação às normas sociais vigentes no grupo de referência dos respondentes de questionários. A seguir, relatamos os primeiros estudos realizados com a intenção de revelar elementos representacionais da zona muda de representações e os estudos atuais sobre esse conceito e descrevemos e discutimos três possíveis explicações para a mudança de representações em situações de substituição ou de descontextualização normativa: a projeção de representações condenáveis pelas normas sociais a outros grupos de representação quando os sujeitos falam por outros grupos e não por si mesmo; o efeito da transparência de representações quando são descritas as representações de grupos conhecidos; o efeito da influência social de normas ou de representações proeminentes no grupo de pertença.

SOCIAL-CONTROL OF GROWTH IN FISH

This review concerns the phenomenon of heterogeneous growth (Het-G) in fish. Het-G is characterized by different growth rates between conspecifics. Although genetic determination on Het-G is recognized, grouping increases the difference in size between conspecifics. This review focuses on population factors and the mechanisms underlying the socially mediated Het-G are summarized and discussed. The aim of this paper is to arrive at a general statement explaining why grouping decreases mean growth and why it suppresses growth only in some individuals. The mechanisms described are: a) food competition, b) chemical factors released by conspecifics, and c) social stress. Social stress is analyzed in terms of the effect on appetite, digestive processes and metabolism. It is proposed that the predominant mechanism promoting socially mediated growth suppression is related to the social habit of the species. The biological significance of growth heterogeneity in fish is also discussed. Growth variability is suggested as an adaptative strategy to optimize survival of the population in a restricted space.