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1.

Aim

To assess and compare the secular trend in age at menarche in Dutch girls (1955–2009) and girls from Turkish and Moroccan descent living in the Netherlands (1997–2009).

Methods

Data on growth and maturation were collected in 20,867 children of Dutch, Turkish and Moroccan descent in 2009 by trained health care professionals. Girls, 9 years and older, of Dutch (n = 2138), Turkish (n = 282), and Moroccan (n = 295) descent were asked whether they had experienced their first period. We compared median menarcheal age in 2009 with data from the previous Dutch Nationwide Growth Studies in 1955, 1965, 1980 and 1997. Age specific body mass index (BMI) z-scores were calculated to assess differences in BMI between pre- and postmenarcheal girls in different age groups.

Results

Median age at menarche in Dutch girls, decreased significantly from 13.66 years in 1955 to 13.15 years in 1997 and 13.05 years in 2009. Compared to Dutch girls there is a larger decrease in median age of menarche in girls of Turkish and Moroccan descent between 1997 and 2009. In Turkish girls age at menarche decreased from 12.80 to 12.50 years and in Moroccan girls from 12.90 to 12.60 years. Thirty-three percent of Turkish girls younger than 12 years start menstruating in primary school. BMI-SDS is significantly higher in postmenarcheal girls than in premenarcheal girls irrespective of age.

Conclusion

There is a continuing secular trend in earlier age at menarche in Dutch girls. An even faster decrease in age at menarche is observed in girls of Turkish and Moroccan descent in the Netherlands.  相似文献   

2.
The Ministry of Health in Uganda in collaboration with the Program for Appropriate Technology for Health (PATH) supported by Bill and Melinda Gates Foundation in 2008–2009 vaccinated approximately 10,000 girls with the bivalent humanpapilloma virus (HPV) vaccine. We assessed parent''s knowledge, risk perception and willingness to allow son(s) to receive HPV vaccines in future through a cross-sectional survey of secondary school boys aged 10–23 years in 4 districts. 377 questionnaires were distributed per district and 870 were used in analysis. Parents that had ever heard about cervical cancer and HPV vaccines; those who would allow daughter(s) to be given the vaccine and those who thought that HPV infection was associated with genital warts were more willing to allow son(s) to receive the HPV vaccine. Unwilling parents considered HPV vaccination of boys unimportant (p = 0.003), believed that only females should receive the vaccine (p = 0.006), thought their son(s) couldn''t contract HPV (p = 0.010), didn''t know about HPV sexual transmissibility (p = 0.002), knew that males could not acquire HPV (p = 0.000) and never believed that the HPV vaccines could protect against HPV (p = 0.000). Acceptance of HPV vaccination of daughters and likelihood of recommending HPV vaccines to son(s) of friends and relatives predicted parental willingness to allow sons to receive HPV vaccines. Probable HPV vaccination of boys is a viable complement to that of girls. Successfulness of HPV vaccination relies on parental acceptability and sustained sensitization about usefulness of HPV vaccines even for boys is vital.  相似文献   

3.
The question of form and extent of biological and/or cultural influences on female and male behaviour and performance is marking a major focus in present scientific research. Accordingly, a broad spectrum of approaches in research and interpretations of results is available. The recent debate on sex and gender is offering two basic objectives for research in education science: First, the critical review of the data and results on sex specifics presented in respect to the articulation of educational aims, topics and methods. Second, the intensified research focus on the developmental consequences of gender and gender roles for boys and girls, women and men. The pedagogical focus is discussed regarding the following three objectives: 1. developmental conditions in early ontogeny, 2. the question of sex specific differences in cognitive abilities in respect to school performance of adolescents, and 3. teaching knowledge on "sex" and "gender" in schools.  相似文献   

4.
The present study contributes to the question of school literacy about the brain, with an original survey conducted on Italian students from the 3rd to 10th grades (n = 508). The main goal was to test student''s knowledge, attitudes, and interests about neuroscience, to assess needs, prospects, and difficulties in teaching about the brain from elementary to high school. A written questionnaire, maintaining anonymity, asked 12 close-ended multiple choice questions on topics related to human and animal brains, plus one facultative open-ended question about interests and curiosities on brain topics. The results show that respondents have a fragmentary level of basic knowledge about the brain, with aspects related to brain functions and consciousness the most challenging. As expected, degrees of performance improve with school level; elementary school students answered correctly an average number of 5.3 questions, middle school 6.5, and high school 7.4. Overall, students show great interest in the brain, as shown by the large number of questions gathered through the open-ended question (n = 384). Other topics are addressed, mostly related to brain structure/functions and the role of the brain in the everyday life. The survey indicates the need of more thorough school programs on this subject, reinforced by interdisciplinary teaching where comparative anatomy and evolutionary aspects of brain development are covered.  相似文献   

5.

Background

The incidence of several adverse pregnancy outcomes including fetal growth restriction are higher in pregnancies where the fetus is male, leading to suggestions that placental insufficiency is more common in these fetuses. Placental insufficiency associated with fetal growth restriction may be identified by multi-vessel Doppler assessment, but little evidence exists regarding sex specific differences in these Doppler indices or placental function. This study aims to investigate sex specific differences in fetal and placental perfusion and to correlate these changes with intra-partum outcome.

Methods and Findings

This is a prospective cohort study. We measured Doppler indices of 388 term pregnancies immediately prior to the onset of active labour (≤3 cm dilatation). Fetal sex was unknown at the time of the ultrasound assessment. Information from the ultrasound scan was not made available to clinical staff. Case notes and electronic records were reviewed following delivery. We report significantly lower Middle Cerebral artery pulsatility index (1.34 vs. 1.43, p = 0.004), Middle Cerebral artery peak velocity (53.47 cm/s vs. 58.10 cm/s, p = <0.001), and Umbilical venous flow/kg (56 ml/min/kg vs. 61 ml/min/kg, p = 0.02) in male fetuses. These differences however, were not associated with significant differences in intra-partum outcome.

Conclusion

Sex specific differences in feto-placental perfusion indices exist. Whilst the physiological relevance of these is currently unknown, the identification of these differences adds to our knowledge of the physiology of male and female fetuses in utero. A number of disease processes have now been shown to have an association with changes in fetal haemodynamics in-utero, as well as having a sex bias, making further investigation of the sex specific differences present during fetal life important. Whilst the clinical application of these findings is currently limited, the results from this study do provide further insight into the gender specific circulatory differences present in the fetal period.  相似文献   

6.

Background

Little is known about the contribution of school contextual factors to individual student body mass index (BMI). We set out to determine if school characteristics/resources: (1) are associated with student BMI; (2) explain racial/ethnic disparities in student BMI; and (3) explain school-level differences in student BMI.

Methods

Using gender-stratified multi-level modeling strategies we examined the association of school characteristics/resources and individual BMI in 4,387 5th graders in the Healthy Passages Longitudinal Study of Adolescent Health. Additionally, we examined the association of race/ethnicity and individual BMI as well as the between-school variance in BMI before and after adding individual and school characteristics to test for attenuation.

Results

The school-level median household income, but not physical activity or nutrition resources, was inversely associated with female BMI (β = −0.12, CI: −0.21,−0.02). Neither school demographics nor physical activity/nutrition resources were predictive of individual BMI in males. In Black females, school characteristics attenuated the association of race/ethnicity and BMI. Individual student characteristics—not school characteristics/resources-reduced the between-school variation in BMI in males by nearly one-third and eliminated it in females.

Conclusions

In this cohort of 5th graders, school SES was inversely associated with female BMI while school characteristics and resources largely explained Black/White disparities in female weight status. Between-school differences in average student weight status were largely explained by the composition of the student body not by school characteristics or programming.  相似文献   

7.

Background

There are 44 million missing women in India. Gender bias; neglect of girls, infanticides and feticides are responsible. The sex ratio at birth can be used to examine the influence of antenatal sex selection on the sex ratio.

Materials and Methods

Records from 321,991 deliveries at one hospital over 11 decades were utilized. The middle year in each decade was taken as representative of the decade. Data from 33,524 deliveries were then analyzed. Data for each decade was combined with that of previous decades and compared to the data of subsequent decades to look for any change in the trend. Sex ratio in the second children against sex of the first child was studied separately.

Results

The mean sex ratio for the 110 years examined was 910 girls to 1000 boys (95% CI; 891 to 930). The sex ratio dropped significantly from 935 (CI: 905 to 967) before 1979, to 892 (CI: 868 to 918) after 1980 (P = 0.04). The sex ratio in the second child was significantly lower if the first child was a girl [716 (CI: 672 to 762] (P<0.001). On the other hand, there was an excess of girls born to mothers whose first child was boy [1140 girls per 1000 boys (CI: 1072 to 1212 P<0.001)].

Conclusions

The sex ratio fell significantly after 1980 when ultra sound machines for antenatal sex determination became available. The sex ratio in second children if the first was a girl was even lower. Sex selective abortions after antenatal sex determination are thus implicated. However data on second children especially the excess of girls born to mothers who have a previous boy seen in the decade before the advent of antenatal ultra sound machines, suggests that other means of sex selection are also used.  相似文献   

8.
9.
In an earlier study we found parental psychiatric symptoms to be a better correlate of behavioral problems in obese children than either child or parental obesity. This study sought to extend this research by assessing the association of general maternal distress, specific maternal psychopathology, family socioeconomic status and child obesity with the psychological problems of 152 children seeking treatment for obesity in two cohorts. Child psychological problems were measured using the Child Behavior Checklist/4–18 (CBCL) in each cohort. In sample 1 maternal general psychiatric symptoms were measured using the Cornell Medical Index (psychiatric subscales) and the Inventory of Interpersonal Problems whereas specific psychopathology was assessed with the Beck Depression Inventory and the Bulimia Test. In sample 2 the Symptom Checklist-90 and Binge Eating Scale provided general and specific measures of psychopathology. In the combined sample, 58% percent of the boys and 44% of the girls met criteria on at least one CBCL behavioral problem scale, with Social Problems the most prevalent problem in both boys and girls. For both samples, child obesity did not account for any variance in child psychosocial problems beyond that accounted for by maternal psychopathology and family SES. Family SES accounted for a significant increment in variance in child behavioral problems in only two scales. This study systematically replicates previous research, adding support for a broader conceptualization of factors that influence psychological problems in obese treatment-seeking children than one which focuses on child obesity.  相似文献   

10.

Background

Sodas are widely sold in vending machines and other school venues in the United States, particularly in high school. Research suggests that policy changes have reduced soda access, but the impact of reduced access on consumption is unclear. This study was designed to identify student, environmental, or policy characteristics that modify the associations between school vending machines and student dietary behaviors.

Methods

Data on school vending machine access and student diet were obtained as part of the National Youth Physical Activity and Nutrition Study (NYPANS) and linked to state-level data on soda taxes, restaurant taxes, and state laws governing the sale of soda in schools. Regression models were used to: 1) estimate associations between vending machine access and soda consumption, fast food consumption, and lunch source, and 2) determine if associations were modified by state soda taxes, restaurant taxes, laws banning in-school soda sales, or student characteristics (race/ethnicity, sex, home food access, weight loss behaviors.)

Results

Contrary to the hypothesis, students tended to consume 0.53 fewer servings of soda/week (95% CI: -1.17, 0.11) and consume fast food on 0.24 fewer days/week (95% CI: -0.44, -0.05) if they had in-school access to vending machines. They were also less likely to consume soda daily (23.9% vs. 27.9%, average difference = -4.02, 95% CI: -7.28, -0.76). However, these inverse associations were observed primarily among states with lower soda and restaurant tax rates (relative to general food tax rates) and states that did not ban in-school soda sales. Associations did not vary by any student characteristics except for weight loss behaviors.

Conclusion

Isolated changes to the school food environment may have unintended consequences unless policymakers incorporate other initiatives designed to discourage overall soda consumption.  相似文献   

11.

Background

Studies have reported that the predictive ability of self-rated health (SRH) for mortality varies by sex/gender and socioeconomic group. The purpose of this study is to evaluate this relationship in Japan and explore the potential reasons for differences between the groups.

Methodology/Principal Findings

The analyses in the study were based on the Aichi Gerontological Evaluation Study''s (AGES) 2003 Cohort Study in Chita Peninsula, Japan, which followed the four-year survival status of 14,668 community-dwelling people who were at least 65 years old at the start of the study. We first examined sex/gender and education-level differences in association with fair/poor SRH. We then estimated the sex/gender- and education-specific hazard ratios (HRs) of mortality associated with lower SRH using Cox models. Control variables, including health behaviors (smoking and drinking), symptoms of depression, and chronic co-morbid conditions, were added to sequential regression models. The results showed men and women reported a similar prevalence of lower SRH. However, lower SRH was a stronger predictor of mortality in men (HR = 2.44 [95% confidence interval (CI): 2.14–2.80]) than in women (HR = 1.88 [95% CI: 1.44–2.47]; p for sex/gender interaction = 0.018). The sex/gender difference in the predictive ability of SRH was progressively attenuated with the additional introduction of other co-morbid conditions. The predictive ability among individuals with high school education (HR = 2.39 [95% CI: 1.74–3.30]) was similar to that among individuals with less than a high school education (HR = 2.14 [95% CI: 1.83–2.50]; p for education interaction = 0.549).

Conclusions

The sex/gender difference in the predictive ability of SRH for mortality among this elderly Japanese population may be explained by male/female differences in what goes into an individual''s assessment of their SRH, with males apparently weighting depressive symptoms more than females.  相似文献   

12.
The goal of this study was to examine the relation of early androgen exposure to sex-typed activities and interests in adolescence. Participants aged 9-19 years included 24 girls and 18 boys with congenital adrenal hyperplasia (CAH) and 16 unaffected sisters and 24 unaffected brothers who served as controls. Using standardized questionnaires, adolescents reported on their participation in sex-typed activities and interest in sex-typed occupations, and parents reported on the adolescents' activities. As hypothesized, girls with CAH showed sex-atypical preferences: increased interest in male-typical activities and careers and reduced interest in female-typical activities and careers compared to the unexposed control girls. These results extend findings of sex-atypical play in young girls with CAH and suggest that the sex-atypical activities and interests of females with CAH reflect direct effects of androgens on the developing brain rather than social responses to virilized genitalia. These results also suggest that population sex differences in activities and interests arise in part from sex differences in early androgens.  相似文献   

13.
Previous research indicates that birth order is a strong predictor of familial sentiments, with middleborns less family-oriented than first- or last-borns. In this research, effects of sex and birth order on the actual frequency of contact with maternal and paternal kin were examined in two studies. In Study 1, one hundred and forty undergraduates completed a questionnaire relating to the amount of time they spent in contact with specific relatives, while in Study 2, one hundred and twelve undergraduates completed the same questionnaire with the addition of two questions relating to the subjects’ parents’ birth orders. Subjects were more likely to have frequent contact with maternal, as opposed to paternal, kin and women experienced more frequent contact than men with relatives in general. The birth order of subjects did not appear to have a significant influence on contact but the birth order of the subjects’ parents did, with the offspring of middleborn mothers having relatively little contact with maternal grandparents and the offspring of middleborn fathers having relatively little contact with paternal grandparents. These sex and birth order differences are discussed in relation to possible differences in how women and men use kinship ties and in terms of how birth order may influence parental solicitude. Catherine Salmon recently received her Ph.D. in psychology from McMaster University in Hamilton Ontario. Her interest in kinship and family relationships has grown out of her own large extended family and many visits to Utah as well as exposure to evolutionary thinking about the family in the lab of Martin Daly and Margo Wilson. Her other current research interests focus on female sexuality and the evolutionary study of literature.  相似文献   

14.
A cross-sectional survey was performed to examine to what degree differences in overweight and obesity between native Dutch and migrant primary school children could be explained by differences in physical activity, dietary intake, and sleep duration among these children. Subjects (n=1943) were primary school children around the age of 8–9 years old and their primary caregivers: native Dutch children (n=1546), Turkish children (n=93), Moroccan children (n=66), other non-western children (n=105), and other western children (n=133). Multivariate regressions and logistic regressions were used to examine the relationship between migrant status, child’s behavior, and BMI or prevalence of overweight, including obesity (logistic). Main explanatory variables were physical activity, dietary intake, and sleep duration. We controlled for age, sex, parental educational level, and parental BMI. Although sleep duration, dietary intake of fruit, and dietary intake of energy-dense snacks were associated with BMI, ethnic differences in sleep duration and dietary intake did not have a large impact on ethnic differences in overweight and obesity among children from migrant and native origin. It is suggested that future preventive strategies to reduce overweight and obesity, in general, consider the role of sleep duration. Also, cross-cultural variation in preparation of food among specific migrant groups, focusing on fat, sugar, and salt, deserves more attention. In order to examine which other variables may clarify ethnic differences in overweight and obesity, future research is needed.  相似文献   

15.
Kuo PC  Huang JH  Liu MD 《PloS one》2011,6(9):e24157

Background

Avian influenza (AI) can be highly pathogenic and fatal. Preventive behavior such as handwashing and wearing face masks has been recommended. However, little is known about what psychosocial factors might influence people''s decision to adopt such preventive behavior. This study aims to explore risk perception and other factors associated with handwashing and wearing face masks to prevent AI.

Methodology/Principal Findings

An interviewer-administered survey was conducted among 352 traditional market workers and shoppers in Taiwan between December 2009 and January 2010. Factors associated with the recommended AI preventive behavior (i.e., when in a traditional market, wearing a face mask and also washing hands after any contact with poultry) included: having correct knowledge about the fatality rate of AI (adjusted odds ratio [AOR] = 4.18), knowing of severe cases of AI (AOR = 2.13), being informed of local AI outbreaks (AOR = 2.24), living in northeastern Taiwan (AOR = 6.01), having a senior high-school education (AOR = 3.33), and having a university or higher education (AOR = 6.86). Gender interactive effect was also found among participants with a senior high-school education, with males being less likely to engage in the recommended AI preventive behavior than their female counterparts (AOR = 0.34).

Conclusions/Significance

Specific information concerning AI risk perception was associated with the recommended AI preventive behavior. In particular, having correct knowledge about the fatality rate of AI and being informed of severe cases and local outbreaks of AI were linked to increased AI preventive behavior. These findings underscore the importance of transparency in dealing with epidemic information. These results also have practical implications for prevention and policy-making to more effectively promote the recommended AI preventive behavior in the public.  相似文献   

16.
Interest to investigate daily fluctuations in cognitive tasks, so-called “school-rhythms”, lies in exploring the most favourable time-of-day for learning considering the analysis of variations in performance taking into account individual differences. The aim of this study was to describe daily fluctuations in attention at three different times of the school day, two different days, considering chronotype and three different school start times (08:00, 08:15 and 08:30?h). Participants were 669 adolescents aged 12–16. Sleep length and inductive reasoning were considered as covariates. In general, attention increased throughout the school day, boys reached higher attention than girls and, moreover, evening type boys reached higher attention than evening type girls. No differences between chronotypes were observed. When students were familiar with the task, chronotype, sex and time-of-day interactions seem to be important factors to consider.  相似文献   

17.

Purposes

This study examined the prevalence of addictive Internet use and analyzed the role of parental relationship in affecting this behavior among a random sample of adolescents in Wuhan, China.

Methods

Students (n = 1,101) were randomly selected from four schools, including 638 boys and 463 girls with a mean age of 13.8 (standard deviation = 1.2) years. Addictive Internet use, parental relationship, hyperactivity-impulsivity were measured by validated instruments. Prevalence rate, ANOVA and multiple linear regression method were used to analyze the level of Internet addiction and its association with parental relationship, hyperactivity-impulsivity, as well as the interaction of parental relationship with chronological age and hyperactivity-impulsivity.

Results

The prevalence rate of Internet addiction was 13.5% (16.5% for boys and 9.5% for girls, p<0.01). Compared to non-addictive users, addictive Internet users were scored significantly lower on parental relationships and significantly higher on hyperactivity-impulsivity. Interaction analysis indicated that better parental relationship was associated with more reductions in risk of addictive Internet use for younger students than for older students, and with more risk of Internet addiction among higher than among lower hyperactivity-impulsivity students.

Conclusions

Findings of this study indicate that adolescent addictive Internet use is a significant public health threat in China. Prevention interventions targeting parental relationship must consider adolescent’s age and hyperactivity-impulsivity tendency.  相似文献   

18.
Evolutionary transitions among maternal, paternal, and bi‐parental care have been common in many animal groups. We use a mathematical model to examine the effect of male and female life‐history characteristics (stage‐specific maturation and mortality) on evolutionary transitions among maternal, paternal, and bi‐parental care. When males and females are relatively similar – that is, when females initially invest relatively little into eggs and both sexes have similar mortality and maturation – transitions among different patterns of care are unlikely to be strongly favored. As males and females become more different, transitions are more likely. If females initially invest heavily into eggs and this reduces their expected future reproductive success, transitions to increased maternal care (paternal → maternal, paternal → bi‐parental, bi‐parental → maternal) are favored. This effect of anisogamy (i.e., the fact that females initially invest more into each individual zygote than males) might help explain the predominance of maternal care in nature and differs from previous work that found no effect of anisogamy on the origin of different sex‐specific patterns of care from an ancestral state of no care. When male mortality is high or male egg maturation rate is low, males have reduced future reproductive potential and transitions to increased paternal care (maternal → paternal, bi‐parental → paternal, maternal → bi‐parental) are favored. Offspring need (i.e., low offspring survival in the absence of care) also plays a role in transitions to paternal care. In general, basic life‐history differences between the sexes can drive evolutionary transitions among different sex‐specific patterns of care. The finding that simple life‐history differences can alone lead to transitions among maternal and paternal care suggests that the effect of inter‐sexual life‐history differences should be considered as a baseline scenario when attempting to understand how other factors (mate availability, sex differences in the costs of competing for mates) influence the evolution of parental care.  相似文献   

19.

Background

Keeping girls in school offers them protection against early marriage, teen pregnancy, and sexual harms, and enhances social and economic equity. Studies report menstruation exacerbates school-drop out and poor attendance, although evidence is sparse. This study qualitatively examines the menstrual experiences of young adolescent schoolgirls.

Methods and Findings

The study was conducted in Siaya County in rural western Kenya. A sample of 120 girls aged 14–16 years took part in 11 focus group discussions, which were analysed thematically. The data gathered were supplemented by information from six FGDs with parents and community members. Emergent themes were: lack of preparation for menarche; maturation and sexual vulnerability; menstruation as an illness; secrecy, fear and shame of leaking; coping with inadequate alternatives; paying for pads with sex; and problems with menstrual hygiene. Girls were unprepared and demonstrated poor reproductive knowledge, but devised practical methods to cope with menstrual difficulties, often alone. Parental and school support of menstrual needs is limited, and information sparse or inaccurate. Girls’ physical changes prompt boys and adults to target and brand girls as ripe for sexual activity including coercion and marriage. Girls admitted ‘others’ rather than themselves were absent from school during menstruation, due to physical symptoms or inadequate sanitary protection. They described difficulties engaging in class, due to fear of smelling and leakage, and subsequent teasing. Sanitary pads were valued but resource and time constraints result in prolonged use causing chafing. Improvised alternatives, including rags and grass, were prone to leak, caused soreness, and were perceived as harmful. Girls reported ‘other girls’ but not themselves participated in transactional sex to buy pads, and received pads from boyfriends.

Conclusions

In the absence of parental and school support, girls cope, sometimes alone, with menarche in practical and sometimes hazardous ways. Emotional and physical support mechanisms need to be included within a package of measures to enable adolescent girls to reach their potential.  相似文献   

20.
School belongingness has gained currency among educators and school health professionals as an important determinant of adolescent health. The current cross-sectional study presents the 15 most significant personal and contextual factors that collectively explain 66.4% (two-thirds) of the variability in 12-year old students’ perceptions of belongingness in primary school. The study is part of a larger longitudinal study investigating the factors associated with student adjustment in the transition from primary to secondary school. The study found that girls and students with disabilities had higher school belongingness scores than boys, and their typically developing counterparts respectively; and explained 2.5% of the variability in school belongingness. The majority (47.1% out of 66.4%) of the variability in school belongingness was explained by student personal factors, such as social acceptance, physical appearance competence, coping skills, and social affiliation motivation; followed by parental expectations (3% out of 66.4%), and school-based factors (13.9% out of 66.4%) such as, classroom involvement, task-goal structure, autonomy provision, cultural pluralism, and absence of bullying. Each of the identified contributors of primary school belongingness can be shaped through interventions, system changes, or policy reforms.  相似文献   

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