The influence of sex, age, and race experience on pacing profiles during the 90 km Vasaloppet ski race

The purpose of this study was to investigate pacing-profile differences during the 90 km Vasaloppet ski race related to the categories of sex, age, and race experience. Skiing times from eight sections (S1 to S8) were analyzed. For each of the three categories, 400 pairs of skiers were matched to have a finish time within 60 seconds, the same start group, and an assignment to the same group for the other two categories. Paired-samples Student’s t-tests were used to investigate sectional pacing-profile differences between the subgroups. Results showed that males skied faster in S2 (P=0.0042), S3 (P=0.0049), S4 (P=0.010), and S1–S4 (P<0.001), whereas females skied faster in S6 (P<0.001), S7 (P<0.001), S8 (P=0.0088), and S5–S8 (P<0.001). For the age category, old subjects (40 to 59 years) skied faster than young subjects (19 to 39 years) in S3 (P=0.0029), and for the other sections, there were no differences. Experienced subjects (≥4 Vasaloppet ski race completions) skied faster in S1 (P<0.001) and S1–S4 (P=0.0054); inexperienced skiers (<4 Vasaloppet ski race completions) had a shorter mean skiing time in S5–S8 (P=0.0063). In conclusion, females had a more even pacing profile than that of males with the same finish time, start group, age, and race experience. No clear age-related pacing-profile difference was identified for the matched subgroups. Moreover, experienced skiers skied faster in the first half whereas inexperienced skiers had higher skiing speeds during the second half of the race.

Sex group composition, social interaction, and metabolism in the fish Nile tilapia

O objetivo deste trabalho foi testar se grupos monossexuais de machos gastam mais energia e exibem perfil agonístico diferente de grupos formados por um macho e uma fêmea na tilápia-do-Nilo (Oreochromis niloticus). Tais diferenças são esperadas, pois machos e fêmeas competem por diferentes recursos reprodutivos. Foram utilizadas duplas de machos (MM) e duplas de macho-fêmea (MF) que permaneceram pareadas por 40 minutos. Durante esse período foi feito o registro da interação agonística (10 minutos iniciais e 10 minutos finais do pareamento) e determinado o gasto energético (consumo de O2) pelo Método de Winckler. A latência para o início dos confrontos (média ± DP, MM = 27,40 ± 25,15 s; MF = 14,22 ± 21,19 s; Mann-Whitney, U = 33,50, P = 0,21) e a freqüência de todas as unidades comportamentais (média ± DP, MM < 72,30 ± 25,29; MF < 73,50 ± 21,65.10/min; Mann-Whitney, P > 0,10) foram semelhantes entre os grupos MM e MF nos 10 minutos iniciais. Isso indica que cada intruso foi considerado um potencial competidor no início da interação. No entanto, a freqüência de ondulação (interação também exibida durante a corte) foi maior para o residente do grupo MF nos 10 minutos finais (média ± DP, MM = 3,56 ± 5,89; MF = 8,56 ± 4,00.10/min; Mann-Whitney, U = 15,50, P = 0,01). A freqüência de fuga, entretanto, foi menor para o intruso do mesmo grupo (média ± DP, MM = 3,90 ± 4,33; MF = 0,44 ± 0,96.10/min; Mann-Whitney, U = 23,50, P = 0,04). Além disso, o perfil agonístico no grupo MM foi composto por um maior número de itens comportamentais do que o MF (para residentes e intrusos). Apesar das diferenças comportamentais, o consumo de O2 não foi afetado pela composição sexual do grupo (média ± DP, MM = 1,93 ± 0,54; MF = 1,77 ± 0,46 mgO2.g peso seco-1.40/min; t-teste de Student, t = 0,71, P = 0,49).

Sex-related macrostructural organization of the deer's brachial plexus

We describe the morphological organization of the deer brachial plexus in order to supply data to veterinary neuroclinics and anaesthesiology. The deer (Mazama gouazoubira) brachial plexus is composed of four roots: three cervical (C6, C7 and C8) and one thoracic (T1). Within each sex group, no variations are observed between the left and the right brachial plexus, though sex-related differences are seen especially in its origin. The origin of axillary and radial nerves was: C6, C7, C8 and T1 in males and C8-T1 (radial nerve) and C7, C8 and T1 (axillary nerve) in females; musculocutaneous nerve was: C6-C7 (males) and C8-T1 (females); median and ulnar nerves was: C8-T1 (males) and T1 (females); long thoracic nerve was: C7 (males) and T1 (females); lateral thoracic nerve was: C6, C7, C8 and T1 (males) and T1 (females); thoracodorsal nerve was: C6, C7, C8 and T1 (males) and C8-T1 (females); suprascapular nerve was: C6-C7 (males) and C6 (females) and subscapular nerve was: C6-C7 (males) and C7 (females). This study suggests that in male deer the origin of the brachial plexus is more cranial than in females and the origin of the brachial plexus is slightly more complex in males, i.e. there is an additional number of roots (from one to three). This sexual dimorphism may be related to specific biomechanical functions of the thoracic limb and electrophysiological studies may be needed to shed light on this morphological feature.

Effects of sex and age on genotype x environment interaction for beef cattle body weight studied using reaction norm models

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Origin and differentiation of a sex chromosome system in Parodon hilarii (Pisces, Parodontidae). Satellite DNA, G- and C-banding

A satellite DNA sequence of Parodon hilarii ( named pPh2004) was isolated, cloned and sequenced. This satellite DNA is composed of 200 bp, 60% AT rich. In situ hybridization ( FISH) results revealed that the satellite DNA pPh2004 is located in the terminal regions of several chromosomes, forming highly evident blocks in some and punctual marks in others. The comparison between the FISH and C-banding results showed that the location of this satellite DNA coincides with that of most terminal heterochromatins. However, some regions are only marked by FISH whereas other regions are only marked by C-banding. The possible existence of more than one satellite DNA family could explain these partial differences. The in situ hybridization with the satellite DNA and the G- and C-bandings confirmed the presence of a sex chromosome system of the ZZ/ZW type in P. hilarii, as well as the correct identification of the Z chromosome in the karyotype. This chromosome displays a segment of terminal heterochromatin in the long arm, similar to the segment observed in the short arm of the W chromosome, also showing a G- banding pattern similar to that of the short arm and part of the long arm of the W chromosome. A hypothesis on the origin of the W chromosome from an ancestral chromosome similar to the Z chromosome is presented.

Gender differences in obsessive-compulsive disorder: a literature review

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

Use of a condom in sex relations by HIV carriers

Para estudar a ocorrência da utilização do preservativo masculino em relações sexuais pelos portadores do HIV, foram entrevistados 132 indivíduos, sendo 82 homens e 50 mulheres. A maioria do Estado de São Paulo e algumas de outras regiões do País, atendidas na Faculdade de Medicina de Botucatu. As mulheres eram mais jovens, tinham menor escolaridade, pior qualificação profissional que os homens, e ainda, maior proporção era de viúvas, separadas, desquitadas e divorciadas. Verificou-se que 43,9% dos homens e 72% das mulheres foram contaminados pela via sexual, mas apenas 41,2% dos primeiros e 31,8% das mulheres referiram utilização do preservativo após o diagnóstico de infecção, a maioria de homens e mulheres preferindo observar abstinência sexual. Os resultados permitem concluir que ainda há necessidade de se manter informação continuada sobre a importância do uso do preservativo, além de se garantir sua distribuição gratuita, pelos baixos níveis de instrução e qualificação profissional dos indivíduos. Sugerem, ainda, que as campanhas de divulgação de medidas preventivas considerem as diferenças sociais e culturais das mulheres que se infectam.

Screening and characterization of sex-specific DNA fragments in the freshwater fish matrinch, Brycon amazonicus (Teleostei: Characiformes: Characidae)

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

Chromosomal painting and ZW sex chromosomes differentiation in Characidium (Characiformes, Crenuchidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morphometric changes associated with sex and development in the Malpighian tubules of Aedes aegypti

The Malpighian tubules of Aedes aegypti showed significant differences in their diameters between male and female larvae, male and female pupae, male larvae and male adults and male pupae and male adults. in every case, female values were greater than in males. Measurements of mean nuclear areas of the principal and stellate cells from Malpighian tubules, taken in males and females during development, showed that this parameter in both types of cell was significantly greater in females than in male larvae, pupae and adult stages. In males, significant differences between developmental stages were observed only in comparison with the nuclear area of larvae and adults in the principal cells, but in females, every comparison between stages showed significant differences except between pupae and adults in stellate cells. The frequency distribution of nuclear area values, in development, for male stellate and principal cells, were mostly concentrated in the first seven classes among the 30 classes considered in every stage, while for females, the frequency dropped drastically in the same classes from larvae to pupae and adults, moving to classes of higher values. Considering the importance of Malpighian tubules in insect physiology, the meaning of the differences detected are discussed on the basis of different metabolic levels, between sexes and developmental stages.

Same-sized fish groups increase aggressive interaction of sex-reversed males Nile tilapia GIFT strain

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cryopreservation of semen from functional sex-reversed genotypic females of the rainbow trout, Oncorhynchus mykiss

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Description of a ZZ/ZW sex chromosome system in Thoracocharax cf. stellatus (Teleostei, Characiformes, Gasteropelecidae)

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

Effects of sex and locality on the abundance of lice on the wild rodent Oligoryzomys nigripes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Size distribution and sex ratio in the spider crab Epialtus brasiliensis (Dana 1852) associated with seaweed on a rocky shore in southeastern Brazil (Crustacea, Decapoda, Brachyura, Majoidea, Epialtidae).

This study analyzed a population of the spider crab Epialtus brasiliensis, in regard to its size distribution, sex ratio and Sexual maturity. The study was conducted on a rocky shore in the Ubatuba region, state of Silo Paulo, Brazil, where a wide strip of algae covers the intertidal zone. A total of 378 specimens were obtained: 200 males (128 juvenile and 72 adult crabs) and 178 females (46 juveniles and 132 adults). Their Sizes ranged from 3.4 to 16.7 mm carapace length (CL). Taking into account that the pubertal and terminal molts are coincident in majid crabs, the maximum sizes attained by males and females are especially dependent on the factors that influence sexual maturity, mainly food resources, temperature and intraspecific competition. Males of E. brasiliensis occurred in all size classes, whereas females occurred only as far the 10th size class (12-13 min CL). file total sex ratio did not differ statistically from 1 : 1, but when the juvenile and adult specimens were analyzed separately the differences between sexes were significantly different, with higher proportions of immature males and mature females. The CL50 calculated for males and females was 10.4, and 6.9 min CL, respectively. Thus, males reach their sexual maturity at a larger size than females. This feature may be important for the reproductive strategy of this species, because larger males probably have greater reproductive Success.