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

Tratamento da doença de Chagas pelo Nifurtimox (Bayer 2502)

Foram tratados 77 pacientes com doença de Chagas pelo nifurtimox, subdivididos em quatro grupos. Grupo I, com 30 pacientes na fase aguda. Somente oito doentes usaram a droga durante 120 dias, na dose inicial de 15 mg/kg de peso corporal e posteriormente de 10 mg. Vinte e dois pacientes tomaram dose insuficiente. Em quatro doentes (50%) o xenodiagnóstico tornou-se negativo pós-tratamento; destes, três fizeram reação de Machado Guerreiro, a qual estava negativa. Houve um óbito por insuficiência cardíaca no 59 dia de tratamento. Seis pacientes apresentaram polineuropatia periférica. Grupo II, com 15 pacientes na fase crônica, tratados em ambulatório. Oito abandonaram o tratamento, mas cinco em dez que tomaram placebo fizeram o mesmo. Dos seis que tomaram a droga durante 120 dias e fizeram pelo menos um xenodiagnóstico pós-tratamento, havia quatro que estavam com os exames negativos. O tratamento não alterou o eletrocardiograma, a área cardíaca ou a radiografia do esôfago dos doentes e não evitou que um paciente viesse a desenvolver insuficiência cardíaca e um outro arritmia. Grupo III, com 15 pacientes na fase crônica, tratados com 10 mg/kg, durante 120 dias. Fizeram 12 xenodiagnósticos mensalmente, cada um com oito caixas contendo 10 T. infestans após o tratamento e somente 28,5% dos pacientes apresentaram todos os exames negativos. Houve acentuada redução da parasitemia, mesmo nos doentes não curados. O número de xenos positivos passou de 43% antes do tratamento para 24,4% após o mesmo e o número de caixas positivas caiu de 29,6% para 7%. Grupo IV, com 17 pacientes na fase crônica, tratados com 8 mg/kg ao dia, sendo que em oito durante 120 dias, em cinco durante 100 dias e em quatro durante 60 dias. A percentagem de doentes com os 12 xenos negativos pós-tratamento foi de 56,25. Também neste grupo houve redução de parasitemia, caindo a percentagem de xenos positivos de 76,5 antes do tratamento para 10,3 e a de caixas positivas de 28,6 para 3,1. Não há vantagem em se prolongar o uso do nifurtimox por mais de dois meses. As percentagens de cura são bem inferiores as obtidas na Argentina, Chile e Rio Grande do Sul. A droga produz muitas reações, sendo a mais importante a polineuropatia periférica.Seventy seven patientes with Chagas disease were treated with nifurtimox. They were divided into 4 groups. Group I consisted of 30 patients in the acute phase of the disease. Twenty two patients took an insufficient dose. Only 8 patients used the drug for 120 days in an initial daity dose of 15 mg/kilogram body weight for up to 2 weeks and later in a daily dose of 10 mg/kilo body weight. In 4 patients (50%) the xenodiagnosis became negativa after treatment and in 3 the Machado Guerreiro test became negative. One patient died with acute cardiac failure on the 5th day of treatment. Six patients developed evidence of sensory peripheral neuritis while on treatment. Group II consisted of 15 outpatients in the chronic phase. They also took the drug for 120 days in a variable dosage of 5-15 mg/kilo body weight. They had at least one xenodiagnosis performedafter treatment in four patients xenodiagnosis became negative. The treatment had no effect on the electrocardiogram, degree of cardiomegaly, or appearance on barium swallow. Treatment did not prevent one patient from developing an arrhythmia and another cardiac failure. Group III also contained 15 patients in the chronic phase with positive xenodiagnosis treated with 10 mg/kilo body weight for 120 days. Twelve serial monthly xenodiagnosis were done after treatment using 80 T. infestans (10 to a box) for each examination. In only 28.5% of the patients were all these xenodiagnoses negative. The frequency of parasitemia was decreased in the other patients but not eradicated. The number of xenodiagnoses positive before treatment was 43% and afterwards 24.4%. The number of positive boxes diminished from 29.6% to 7%. Group IV consisted of 17 patients in the chronic phase with positive xenodiagnosis treated with 8 mg/kg per day. Eight were treated with this dose for 120 days, 5 for 100 days and 4 for 60 days. The percentage of patients with 12 serial xenodiagnoses negative after treatment was 56.25%. A reduction in the incidence of positive xenodiagnoses from 76.5 to 10.3% also ocurred in this group and the number of positive boxes diminished from 28.6 to 3.1%. There is no advantage in prolonging treatment beyond 2 months. The percentage of cure is much less than that obtained in Argentina, Chile or Rio Grande do Sul (Brazil). The drug produces many side effects especially a peripheral neuritis