Perfeccionismo, auto-apresentação e ansiedade na competição desportiva e na prática de exercício: estudo exploratório com atletas de competição e praticantes de exercício

Esta investigação exploratória procurou analisar o padrão de relações entre perfeccionismo, ansiedade física e social, percepção de ameaça e auto-apresentação em atletas de competição (taekwondo e kickboxing) e em praticantes regulares de exercício. Participaram no estudo 107 indivíduos de ambos os sexos, com idades compreendidas entre os 14 e os 38 anos, envolvidos em competições oficiais de “taekwondo” (N=42), “kickboxing” (N=20) e na prática de exercício em “health clubs” ou ginásios (N=47). Foram administradas versões traduzidas e/ou adaptadas dos seguintes instrumentos: a) Escala Multidimensional de Perfeccionismo no Desporto (Dunn e tal., 2002); b) Questionário de Auto-Apresentação (Gammage et al., 2003); c) Escala de Ansiedade no Desporto e Actividade Física (Norton et al., 2004); d) Escala de Percepção de Ameaça (Cruz, 1996). Os resultados sugerem moderadas a fortes relações entre todas dimensões do perfeccionismo, diferentes medidas da ansiedade (competitiva, física e social) e diferentes dimesões da auto-apresentação (construção da impressão e motivação para a impressão). Foram também evidentes diferenças significativas em função do grupo (competição vs exercício)

Opioids, sex and gender

JUSTIFICATIVA E OBJETIVOS: Sexo é um fator importante na modulação da experiência dolorosa. Evidências significativas têm demonstrado que a experiência à dor difere entre homens e mulheres, bem como na resposta à ativação do sistema opioide e seus efeitos analgésicos. Há evidências que as mulheres têm menor limiar que os homens para alguns estímulos álgicos. Os neurotransmissores opioides e seus receptores estão centralmente envolvidos na resposta ao estresse, na supressão à dor e na ação dos analgésicos opioides. O objetivo deste estudo foi analisar a relação entre sexo, gênero e sistema opioide e discutir a relevância de um dos aspectos mais intrigantes da fisiologia da dor: a presença da diferença entre sexo e gênero, sistema opioide e as respostas da analgesia por opioides. CONTEÚDO: Uma revisão da literatura sobre opioides, sexo e gênero, cujo objetivo foi mostrar dados atuais sobre a experiência dolorosa entre homens e mulheres, a ativação opioide central e a resposta aos analgésicos opioides. CONCLUSÃO: Os dados disponíveis na literatura, e os trabalhos em andamento indicam que o sexo provavelmente seja responsável pelas diferenças à analgesia opioide em homens e mulheres, mas a direção e a magnitude destas diferenças dependem de variáveis que se interagem. Como fatores importantes que interagem na percepção dolorosa e na resposta analgésica opioide, devem ser levados em consideração os fatores socioculturais e biológicos, incluindo as variações hormonais em mulheres e a presença do hormônio masculino nos homens.BACKGROUND AND OBJECTIVES: Sex is a major factor for pain modulation. Significant evidences have shown that pain experience is different between men and women, as well as the response to opioid system activation and its analgesic effects. There are evidences that women have lower pain threshold compared to men. Opioid neurotransmitters and their receptors are centrally involved with stress response, pain suppression and opioids analgesic action. This study aimed to illustrate the relationship between sex, gender and the opioid system and to discuss the relevance of one of the most intriguing aspects of pain physiology: differences between sex and gender, opioid system and opioids analgesic response. CONTENTS: A literature review on opioids, sex and gender, aiming to show current data on pain experience between men and women, central opioid activation and response to opioids. CONCLUSION: Data in the literature and ongoing studies indicate that sex is probably responsible for differences in opioid analgesia between men and women, but the direction and magnitude of such differences depend on interacting variables. Socio-cultural and biological factors, including hormonal variations in women and the presence of male hormone in men are important factors interacting with pain perception and opioid analgesic response

Evolving division of labor in a response threshold model

The response threshold model explains the emergence of division of labor (i.e., task specialization) in an unstructured population by assuming that the individuals have different propensities to work on different tasks. The incentive to attend to a particular task increases when the task is left unattended and decreases when individuals work on it. Here we derive mean-field equations for the stimulus dynamics and show that they exhibit complex attractors through period-doubling bifurcation cascades when the noise disrupting the thresholds is small. In addition, we show how the fixed threshold can be set to ensure specialization in both the transient and equilibrium regimes of the stimulus dynamics. However, a complete explanation of the emergence of division of labor requires that we address the question of where the threshold variation comes from, starting from a homogeneous population. We then study a structured population scenario, where the population is divided into a large number of independent groups of equal size, and the fitness of a group is proportional to the weighted mean work performed on the tasks during a fixed period of time. Using a winner-take-all strategy to model group competition and assuming an initial homogeneous metapopulation, we find that a substantial fraction of workers specialize in each task, without the need to penalize task switching

Genome Wide Association Study for Heifer Pregnancy in Nellore Cattle

Considering the economic importance of sexual precocity in Brazilian beef cattle production systems, we were interested in a genome wide association study (GWAS) to find genomic regions that might explain the genetic variability of precocity assessed from heifer pregnancy rates. Given each suggestive region of large effect, we were interested in contrasting the two paternally-inherited haplotype alleles to identify sires that were heterozygous for the effect caused by that region. The database consists of reproductive information on 1,337 Bos indicus Nellore heifers, from three different herds in Brazil. GWAS results identified genomic regions on chromosomes 5, 14 and 18 that explained more than 1% of the total genetic variance. Haplotype analysis for the chromosome 5 region showed heterozygote sires with significant differences in reproduction between their half-sib progenies

NEEM: network-friendly epidemic multicast

Epidemic, or probabilistic, multicast protocols have emerged as a viable mechanism to circumvent the scalabil- ity problems of reliable multicast protocols. However, most existing epidemic approaches use connectionless transport protocols to exchange messages and rely on the intrinsic robustness of the epidemic dissemination to mask network omissions. Unfortunately, such an approach is not network- friendly, since the epidemic protocol makes no effort to re- duce the load imposed on the network when the system is congested. In this paper, we propose a novel epidemic protocol whose main characteristic is to be network-friendly. This property is achieved by relying on connection-oriented transport connections, such as TCP/IP, to support the com- munication among peers. Since during congestion mes- sages accumulate in the border of the network, the pro- tocol uses an innovative buffer management scheme, that combines different selection techniques to discard messages upon overflow. This technique improves the quality of the information delivered to the application during periods of network congestion. The protocol has been implemented and the benefits of the approach are illustrated using a com- bination of experimental and simulation results