The differences of learning and memory between males and females have been well documented and confirmed by both human and animal studies. The sex differences in cognition started from early stage of neuronal developm...The differences of learning and memory between males and females have been well documented and confirmed by both human and animal studies. The sex differences in cognition started from early stage of neuronal development and last through entire lifespan. The major biological basis of the gender-dependent cognitive activity includes two major components： sex hormone and sex-related characteristics, such as sex- determining region of the Y chromosome （SRY） protein. However, the knowledge of how much biology of sex contributes to normal cogni- tive function and elite athletes in various sports are still pretty limited. In this review, we will be focusing on sex differences in spatial learning and memory -- especially the role of male- and female-type cognitive behaviors in sports.展开更多
Background: Sexual size dimorphism(SSD) occurs in a wide range of species in birds and other animals, but the magnitude of SSD often varies with environmental conditions. In general, in the developmental stages, the l...Background: Sexual size dimorphism(SSD) occurs in a wide range of species in birds and other animals, but the magnitude of SSD often varies with environmental conditions. In general, in the developmental stages, the larger sex is more vulnerable to adverse environmental conditions because the larger sex requires more energy than the smaller sex. However, this may not hold true for birds with large brood sizes; the larger sex can acquire more food by suppressing the smaller sex. In addition, most previous studies have been experimental, such as by manipulating clutch size and ectoparasites, which may not reflect natural conditions.Methods: In the present study, we propose a general framework to assess sexual differences in environmental sensitivity in natural populations. Because environmental conditions change throughout the breeding season, seasonal changes of nestling SSD and sex ratio should reflect sexual differences in environmental sensitivity. We applied this approach to a large dataset(1555 nestlings over 5 years) of Japanese Tits(Parus minor). In this population, the male nestling is generally larger than the female(5% SSD in body weight).Results: We found that the magnitude of SSD(weight, tarsus, wing) and fledgling sex ratio increased both in the beginning and the end of the breeding season.Conclusion: Our study suggested that female nestlings are more valuable to poor environmental conditions in the relatively fecund species. This study underscores the importance of brood size on sexual differences in environmental stochasticity and our framework encourages comparative analysis among different bird species.展开更多
Snail eater pangasius （Pangasius conchophilus） is a freshwater fish species indigenous to Mekong-Chaophraya Basin, and is an economic fish in Thailand. This paper reviews some Thai research papers for referable bene...Snail eater pangasius （Pangasius conchophilus） is a freshwater fish species indigenous to Mekong-Chaophraya Basin, and is an economic fish in Thailand. This paper reviews some Thai research papers for referable benefit of international countries. The relationships of fecundity with body length and weight of wild population are related （F = 0.54L3339, F = 435.41W^S399）. Length-weight relationships of both sexes are W = 0.0059L3044s. Sex ratio is 1：1 and spawning season starts during March to June, the egg is adhesive demersal. Average mature size of both sexes are from 40-60 cm TL and 1,100-2,900 g. Effect of 3 types of hormone on induced ovulation, including HCG, pituitary gland, and buserelin in combination with domperidone are not signiticantly different （P 〉 0.05）. Hatching occurs in 24-25 hours after fertilization. The hatching percentage is 80%. Nursing and feeding strategies are also reviewed in this paper.展开更多
基金supported by the American Health Assistance Foundation(G2006-118)the National Institutes of Health(R01AG032441-01 and R01AG025888)
文摘The differences of learning and memory between males and females have been well documented and confirmed by both human and animal studies. The sex differences in cognition started from early stage of neuronal development and last through entire lifespan. The major biological basis of the gender-dependent cognitive activity includes two major components： sex hormone and sex-related characteristics, such as sex- determining region of the Y chromosome （SRY） protein. However, the knowledge of how much biology of sex contributes to normal cogni- tive function and elite athletes in various sports are still pretty limited. In this review, we will be focusing on sex differences in spatial learning and memory -- especially the role of male- and female-type cognitive behaviors in sports.
文摘Background: Sexual size dimorphism(SSD) occurs in a wide range of species in birds and other animals, but the magnitude of SSD often varies with environmental conditions. In general, in the developmental stages, the larger sex is more vulnerable to adverse environmental conditions because the larger sex requires more energy than the smaller sex. However, this may not hold true for birds with large brood sizes; the larger sex can acquire more food by suppressing the smaller sex. In addition, most previous studies have been experimental, such as by manipulating clutch size and ectoparasites, which may not reflect natural conditions.Methods: In the present study, we propose a general framework to assess sexual differences in environmental sensitivity in natural populations. Because environmental conditions change throughout the breeding season, seasonal changes of nestling SSD and sex ratio should reflect sexual differences in environmental sensitivity. We applied this approach to a large dataset(1555 nestlings over 5 years) of Japanese Tits(Parus minor). In this population, the male nestling is generally larger than the female(5% SSD in body weight).Results: We found that the magnitude of SSD(weight, tarsus, wing) and fledgling sex ratio increased both in the beginning and the end of the breeding season.Conclusion: Our study suggested that female nestlings are more valuable to poor environmental conditions in the relatively fecund species. This study underscores the importance of brood size on sexual differences in environmental stochasticity and our framework encourages comparative analysis among different bird species.
文摘Snail eater pangasius （Pangasius conchophilus） is a freshwater fish species indigenous to Mekong-Chaophraya Basin, and is an economic fish in Thailand. This paper reviews some Thai research papers for referable benefit of international countries. The relationships of fecundity with body length and weight of wild population are related （F = 0.54L3339, F = 435.41W^S399）. Length-weight relationships of both sexes are W = 0.0059L3044s. Sex ratio is 1：1 and spawning season starts during March to June, the egg is adhesive demersal. Average mature size of both sexes are from 40-60 cm TL and 1,100-2,900 g. Effect of 3 types of hormone on induced ovulation, including HCG, pituitary gland, and buserelin in combination with domperidone are not signiticantly different （P 〉 0.05）. Hatching occurs in 24-25 hours after fertilization. The hatching percentage is 80%. Nursing and feeding strategies are also reviewed in this paper.
