Effect of early experience and age on initial responsiveness ofTilapia mossambica fry to a maternal model

Fry of the maternal mouth brooding fishTilapia mossambica were tested for the effects of (1) rearing and (2) increasing age on initial responsiveness to a gray disk covered with small black pits that served as a maternal model. In the first experiment, the eggs were removed from their mother’s mouth shortly after spawning, hatched, and the fry raised in groups, singly in complete visual isolation, or by the mother (control) until testing. When free swimming, the fry were tested individually for responsiveness to the model. High levels of responsiveness were exhibited by all fry regardless of rearing experience, indicating that responsiveness to the mother’s mouth is fully developed at birth and needs no previous social experience for its expression. In the second experiment, naive group-reared fry were tested individually for initial responsiveness to the model at 13, 16, 20, or 26 days postspawning. It was found that naive fry were strongly attracted to the model at 13 and 16 days of age but were neutral or actively avoiding it at 26 days of age. This decline is almost identical to the decline in responsiveness of normally reared fry toward their actual mother.     

Population growth, trophic level, and reproductive biology of two congeneric archer fishes （Toxotes chatareus, Hamilton 1822 and Toxotesjaculatrix, Pallas 1767） inhabiting Malaysian coastal waters

Population growth, trophic level, and some aspects of reproductive biology of two congeneric archer fish species, Toxotes chatareus and Toxotes jaculatrix, collected from Johor coastal waters, Malaysia, were studied. Growth pattern by length-weight relationship (W=aL~b) for the sexes differed, and exhibited positive allometric growth (male, female and combined sexes of T. chatareus; female and combined sexes of T. jaculatrix) and isometric growth (male samples of T. jaculatrix only). Trophic levels of both species were analyzed based on 128 specimens. The results show that, in both species, crustaceans and insects were the most abundant prey items, and among crustaceans the red clawed crab Sesarma bidens and Formicidae family insects were the most represented taxa. The estimated mean trophic levels for T. chatareus and T. jaculatrix were 3.422±0.009 and 3.420±0.020, respectively, indicating that they are largely carnivores. Fecundity of T. chatareus ranged from 38354 to 147185 eggs for females with total length ranging from 14.5 to 22.5 cm and total body weight from 48.7 to 270.2 g, and T. jaculatrix 25 251 to 150456 eggs for females with total length ranging from 12.2 to 23.0 cm and total body weight from 25.7 to 275.0 g. Differences in values of gonadosomatic and hepatosomatic indexes calculated for both species in this study may have resulted from uneven sample size ranges.     

Revisiting “The fertilization fairytale:” an analysis of gendered language used to describe fertilization in science textbooks from middle school to medical school

Emily Martin’s (Signs J Women Cult Soc 16(31):485–501, 1991) article, “The Egg and the Sperm: How Science Has Constructed a Romance Based on Stereotypical Male–Female Roles,” was published in Signs over 20 years ago. In this groundbreaking article, she discusses how gender roles are often projected onto reproductive biology, leading to the portrayal of eggs as passive and sperm as active. We were interested in seeing if many of her findings are still relevant today. We analyzed science textbooks from the middle school to the medical school level to determine if fertilization in human reproduction is described in gender-biased language regarding the sentence structure, amount of information provided for female and male processes/parts, and neutrality in describing female and male processes/parts. Although there has been much improvement, there is still a long way to go. Sexist language in scientific textbooks is troubling because it negatively affects both female and male students and undermines teachers’ ability to teach in an accurate and gender-neutral way.     

南方大口鲶幼鱼死亡敏感期及开口饵料试验

本文报导了南方大口鲶幼鱼的死亡存在一个敏感期.出现于内源性营养阶段进入混合性营养阶段,即孵化后的第4-10天内.幼鱼饲养中,水蚯蚓比枝角类生长要快.     

南方大口鲶幼鱼死亡敏感期及开口饵料试验

本文报导了南方大口鲶幼鱼的死亡存在一个敏感期．出现于内源性营养阶段进入混合性营养阶段，即孵化后的第4一10天内．幼鱼饲养中，水蚯蚓比枝角类生长要快．     

Antioxidant activity and protective effect of Clitoria ternatea flower extract on testicular damage induced by ketoconazole in rats

Background

Ketoconazole (KET), an antifungal drug, has adverse effects on the male reproductive system. Pre-treatments with antioxidant plant against testicular damage induced by KET are required. The flowers of Clitoria ternatea (CT) are proven to have hepatoprotective potential. However, the protective effect on KET-induced testicular damage has not been reported.

Objective

To investigate the protective effect of CT flower extracts with antioxidant activity on male reproductive parameters including sperm concentration, serum testosterone level, histopathology of the testis, and testicular tyrosine phosphorylation levels in rats induced with KET.

Methods

The antioxidant activity of CT flower extracts was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Male rats were treated with CT flower extracts (10, 50, or 100 mg/kg BW) or distilled water via a gastric tube for 28 d (preventive period: Days 1–21) and induced by KET (100 mg/kg BW) via intraperitoneal injection for 7 d (induction period: Days 22–28). After the experiment, all animals were examined for the weights of the testis, epididymis plus vas deferens and seminal vesicle, serum testosterone levels, sperm concentration, histological structures and diameter of testis, and testicular tyrosine phosphorylation levels by immunoblotting.

Results

The CT flower extracts had capabilities for DPPH scavenging and high reducing power. At 100 mg/kg BW, the extract had no toxic effects on the male reproductive system. Significantly, in CT+KET groups, CT flower extracts (50 and 100 mg/kg BW) alleviated the reduction of reproductive organ weight parameters, testosterone levels, and sperm concentration. In addition, CT flower extracts gave protection from testicular damage in KET-induced rats. Moreover, in the CT100+KET group, CT flower extracts significantly enhanced the expression of a testicular 50-kDa tyrosine phosphorylated protein compared with that of other groups.

Conclusions

C. ternatea flower extracts possessing antioxidant activity are not harmful to the male reproductive system and can protect against testicular damage in KET-induced rats.     

CuSO4对果蝇的发育毒性与生殖毒性

本实验以模式生物果蝇为实验材料,包括红眼果蝇和白眼果蝇两种不同的品系,以0.05mg/mL、0.1mg/mL、0.5mg/mL、1 mg/mL四个不同浓度梯度的CuSO4染毒组以及空白对照组培养果蝇,以其F1代果蝇的生长发育速度、雌雄比例、亲本的生殖能力作为测量终点,探讨不同浓度的铜离子对果蝇的生长发育的影响.结果表明：1 mg/mL组对卵具有致死效应,在不致死浓度范围内,随着铜离子的浓度增加,果蝇从卵发育为成虫的速度越慢,且生殖能力越低.含有CuSO4的培养基培养的果蝇其F1代果蝇的雌雄比例也高于空白组.可见铜离子对果蝇具有发育毒性和生殖毒性.     

双斑东方鲀人工育苗技术的探讨

综述了福建省水产研究所双斑东方的人工育苗过程,认为:(1)双斑东方属一次产卵型鱼类,性腺退化明显,仔鱼有相互残杀的习性;(2)缩短亲鱼暂养时间,及时催产。通过人工调控,可实现雌雄亲鱼性腺同步化,有效提高受精率;(3)孵化前期加大充气量,孵化后期加大换水量,有利于孵化率的提高;(4)仔鱼培育后期,应及时投足轮虫和分养仔鱼,并逐渐加大充气量和藻液的密度,从而提高出苗率。     

江西婺源蓝尾石龙子形态特征的两性异形

报道了江西婺源地区蓝尾石龙子（Eumeces elegans）头、体大小的两性异形.蓝尾石龙子成体体长存在显著的两性差异（雄性大于雌性）,雄性个体有较大的头部（头长和头宽）,雄性头部增长速率明显大于雌性,表明成年雄体分配较多的能量用于头部和身体的生长;而成年雌体则相对延缓头部的生长,以维持躯干生长,增大腹腔容纳量,可提高其繁殖输出.     

日本锦鲤人工繁殖技术和胚胎发育过程观察

报道了日本锦鲤亲鱼培育方法和胚胎发育各期形态特征及发育特点,总结出日本锦鲤亲鱼池塘培育和人工繁育的技术方法.锦鲤卵属沉性卵,具粘性,于水温20～23℃时,多数受精卵经82小时后孵化出苗,初孵化仔鱼全长7～8 mm,三天后卵黄囊基本被吸收,可平游并开口摄食.     

贵州农村少数民族男性性行为现状分析

文章以贵州五个少数民族男性为对象,进行男性人口性行为现状进行研究。通过分层整群抽样法抽取苗族、侗族、布依族、仡佬族和水族男性人口,认为少数民族地区学生性观念相对保守;青少年性与生殖健康教育仍然是空白;而已婚人群性与生殖健康水平也有待提高。     

Childhood sexual victimization,pedophilic interest,and sexual recidivism

Objective

The goal of the current study was to examine the extent to which child sexual abuse (CSA) and particular characteristics of CSA are associated with pedophilic interest and sexual recidivism.

Methods

Subjects were 462 adult male sexual offenders who had been incarcerated in Canadian federal prisons.

Results

Compared to sexual offenders who had not been sexually abused, those who had been sexually abused before age 16 sexually offended against significantly younger victims and had significantly more indicators of pedophilic interest. This was the case whether we examined self-reported or officially documented CSA. Offenders who had been sexually abused exclusively by a male had significantly more indicators of pedophilic interest than those who had been sexually abused exclusively by a female. These findings are consistent with past research and theory suggesting that CSA may play a role in pedophilia and sexual offending against children. CSA exclusively by a female abuser predicted higher rates of sexual recidivism than abuse by a male or both a male and female abuser. Among offenders with victims 15 years old or younger, a closer relationship between offender and abuser predicted higher rates of sexual recidivism. The relationship between CSA and sexual recidivism was significantly moderated by actuarial risk. More specifically, CSA predicted higher rates of sexual recidivism among higher risk offenders, but CSA did not predict sexual recidivism among lower risk offenders. This novel finding raises the possibility that CSA may play a role in sexual recidivism for some offenders.

Conclusion

If future research replicates this CSA by risk interaction and identifies the constructs and processes involved, CSA may be worth considering in risk assessment and treatment.     

Partial AZFc duplications not deletions are associated with male infertility in the Yi population of Yunnan Province, China

Objective: There are many reports on associations between spermatogenesis and partial azoospermia factor c (AZFc) deletions as well as duplications; however, results are conflicting, possibly due to differences in methodology and ethnic background. The purpose of this study is to investigate the association of AZFc polymorphisms and male infertility in the Yi ethnic population, residents within Yunnan Province, China. Methods: A total of 224 infertile patients and 153 fertile subjects were selected in the Yi ethnic population. The study was performed by sequence-tagged site plus/minus (STS+/−) analysis followed by gene dosage and gene copy definition analysis. Y haplotypes of 215 cases and 115 controls were defined by 12 binary markers using single nucleotide polymorphism on Y chromosome (Y-SNP) multiplex assays based on single base primer extension technology. Results: The distribution of Y haplotypes was not significantly different between the case and control groups. The frequencies of both gr/gr (7.6% vs. 8.5%) and b2/b3 (6.3% vs. 8.5%) deletions do not show significant differences. Similarly, single nucleotide variant (SNV) analysis shows no significant difference of gene copy definition between the cases and controls. However, the frequency of partial duplications in the infertile group (4.0%) is significantly higher than that in the control group (0.7%). Further, we found a case with sY1206 deletion which had two CDY1 copies but removed half of DAZ genes. Conclusions: Our results show that male infertility is associated with partial AZFc duplications, but neither gr/gr nor b2/b3 deletions, suggesting that partial AZFc duplications rather than deletions are risk factors for male infertility in Chinese-Yi population.     

Bad boys,good girls? Implicit and explicit attitudes toward ethnic minority students among elementary and secondary school teachers

Teachers’ attitudes toward ethnic minority students might differ by students’ gender and the type of school teachers are working in because of different motivations for teaching and different school practices. Hence, the aim of the current research was to investigate elementary (n = 82) and secondary school (n = 82) teachers’ implicit and explicit attitudes toward male and female ethnic minority students. Teachers worked on either a male or a female Implicit Association Test and filled out a gender-specific questionnaire for measuring explicit attitudes. The results showed that elementary and secondary school teachers had negative implicit attitudes toward ethnic minority students, independent of students’ gender. Whereas secondary school teachers were implicitly more positive toward boys, elementary school teachers were implicitly more positive toward girls. Elementary school teachers were more enthusiastic about teaching ethnic minority boys than girls. The findings provide the first insights into differences in attitudes between elementary and secondary school teachers.     

凤鲚瓯江种群的生物学特性

2006年5—8月对浙南瓯江凤鲚的繁殖期生物学特性进行了调查和研究．结果表明,凤鲚瓯江种群汛期雌雄个体体重（W）与体长（L）的关系分别为Wf=0．021 Lf^2.52（R^2=0．77）和Wm=0．0127 Lm^2.605（R^2=0．72）．个体绝对繁殖力在2836—62901粒之间,平均为（21112±8919）粒;绝对繁殖力（r）与体长（L）、体重（W）和纯重（NW）均呈线性正相关．相对繁殖力（r／L）与体长、体重呈线性正相关,平均个体相对繁殖力（r／L）为（1146±398）粒／cm;相对繁殖力（HW）与体长、体重无关,平均个体相对繁殖力（HW）为（657±186）粒/g．     

Duchenne型肌营养不良1例临床和遗传学咨询

目的通过分析1例Duchenne型肌营养不良症家系患者的临床资料,对家系相关成员进行了遗传优生咨询和生殖干预,以期减少或避免患儿的出生。方法全面家系调查后绘制系谱图并进行遗传学分析、再发风险评估和遗传优生咨询。结果以先证者为线索调查此家系四代33人,其中有患者5例,均为男性。对家庭成员进行了有效的生殖干预,避免了患儿的再出生。结论对家系成员进行生殖干预对避免患儿的出生有重要指导意义;由于本病迄今尚无有效治疗方法,系谱分析、携带者筛查及产前诊断是预防本病的关键。     

丈夫生育权保护制度的构建

丈夫生育权以婚姻关系中的男性为主体,具有人格权和身份权合一的性质,多受妻子生育权限制,是受国家保护的人权以及法律保障实现的权利。丈夫生育权应由亲属法确认,受计划生育义务、子女权益、妻子健康状况和妻子生育优先决定权的限制,应明确侵害丈夫生育权行为类型和侵权请求权行使,以构建科学合理的丈夫生育权保护制度。     

The effects of individual characteristics,socioeconomic status,and political engagement on the attainment of student leadership roles in Chinese university students

This study analyzes the effects of individual characteristics, socioeconomic status, and political engagement among Chinese university students with respect to their attainment of student leadership roles. The study investigated 10,930 students from elite Chinese universities. The results showed that female and only-child students were more likely to become student leaders than male students and students with siblings. Students from local Hukou (household registration) were less likely than students from nonlocal Hukou, to become student leaders. Each upgrade of one level in the membership of the Chinese Communist Party doubled the students’ odds for attaining student leadership roles.     

Older opposite-sex romantic partners,sexual risk,and victimization in adolescence

This study examined how age gaps among opposite-sex romantic partners related to sexual risk-taking and victimization by partners among 201 at-risk adolescents (60.2% female). We examined three questions: (a) is younger partner age, age gap between partners, or a combination of these two factors most strongly related to negative outcomes; (b) do age gaps relate to negative outcomes differently for male versus female adolescents; and (c) why do age gaps relate to negative outcomes? Results revealed that the wider the age gap between partners, the more likely adolescents were to engage in sex and the less likely they were to use protection against pregnancy and STIs. Wider age gaps were also associated with more frequent emotional and physical victimization and higher odds of unwanted sexual behavior. Findings did not differ significantly by gender or younger partner age. Analyses revealed that the wider the age gap, the more likely both partners were to engage in risky lifestyles (i.e., substance use and delinquency), and risky lifestyles – rather than poor negotiation or decision-making equality – helped to explain associations between age gaps and engagement in sexual intercourse and victimization experiences. Results suggest that relationships with age gaps tend to involve two partners who are engaging in deviant lifestyles overall, further corroborating the need to identify and provide services to these youth. Results also support movements toward considering partner age gaps rather than relying on a set age of consent when determining adolescents’ legal competency to consent to sex.