Since the discovery of gonadotropin-releasing hormone (GnRH) in mammals at the beginning of the 1970s, it was generally accepted that GnRH is the only hypothalamic neuropeptide regulating gonadotropin release in mammals and other vertebrates. In 2000, however, gonadotropin-inhibitory hormone (GnIH), a novel hypothalamic neuropeptide that actively inhibits gonadotropin release, was discovered in quail. Numerous studies over the past decade and a half have demonstrated that GnIH serves as a key player regulating reproduction across vertebrates, acting on the brain and pituitary to modulate reproductive physiology and behavior. In the latter case, recent evidence indicates that GnIH can regulate reproductive behavior through changes in neurosteroid, such as neuroestrogen, biosynthesis in the brain. This review summarizes the discovery of GnIH, and the contributions to GnIH research focused on its mode of action, regulation of biosynthesis, and how these findings advance our understanding of reproductive neuroendocrinology.
In this paper, we studied some biological aspects of big eye scad (Selar crumenophthalmus) from Maldives. The fish sample was collected from the local fish market at Bangaa Faru, Male, Maldives. The length of the samples were ranged from 7.7 cm to 24.5 cm (mean value = 16.85 ± 2.82 cm) in fork length. Body weight ranged between 8 g to 255.6 g (mean value = 87.76 ± 40.41 g). The exponent values (b slope) of lengthweight relationship of S. crumenophthalmus are 2.9838 for females and 2.7687 for males; indicating negative allometric growth pattern for both sexes. Synchronous reproductive behaviour was observed in both sexes and a pronounced peak of Gonadosomatic index was observed in females in January 2013. It is estimated that length at first maturity (L50) for females is at 19.39 cm FL and for males at 21.76 cm FL. Our result also suggest that big eye scad have a reduced swimming capability, resulting the species to be easily caught. Careful planning and management should be implemented to prevent the big eye scad from being overfished.
BACKGROUND: The increasing trend of premarital sexual experience and unintended pregnancies in Malaysia warrants sustained and serious attention. The sensitivities of sex-related issues in a Muslim-majority country create various types of barriers to sexual and reproductive health information, support and practices. This study aims to gain understanding of knowledge, attitudes and behaviours of young women in Malaysia concerning reproductive, contraception and premarital sexual practices.
METHODS: A cross-sectional study was performed, using an anonymous self-administered questionnaire carried out among 1695 female university students in a public university in Malaysia.
RESULTS: Respondents had low scores for knowledge of reproduction and pregnancy (median=4, of maximum score 10), contraceptive uses (median=6, of maximum score 16) and contraceptive availability (median=3, of maximum score 13). The majority of women surveyed do not have liberal values in relation to premarital sexual behaviour (median=37, of maximum 40); higher scores on this scale corresponded to opposing premarital sex. The multivariate analyses showed that ethnic group was the strongest correlate of knowledge and attitude scores; being of Malay Muslim ethnicity was associated significantly with lower knowledge scores and premarital sex permissiveness. Other significant correlates were year of study, maternal occupational groups, level of religious faith, dating status and urban-rural localities. Level of premarital sex permissiveness was inversely correlated with reproduction and pregnancy knowledge score, and contraceptive knowledge scores.
CONCLUSION: Reproductive health knowledge and attitudes were intricately linked to religious values and cultural norms differences surrounding sexual issues.