WorldWideScience

Sample records for pubertal timing effects

  1. Effects of harsh parenting and positive parenting practices on youth aggressive behavior: The moderating role of early pubertal timing.

    Science.gov (United States)

    Chen, Frances R; Raine, Adrian

    2018-01-01

    Prior research indicates that early pubertal timing is associated with aggressive behavior, particularly in the context of adversity as postulated in the contextual amplification hypothesis. However, few studies have examined harsh parenting as the context for the effect of early pubertal timing. Even fewer studies have tested the interactive effect of early pubertal timing and positive parenting on aggressive behavior. In this study, we tested the proposition that early pubertal timing, contrary to the general conception of it as a vulnerability, indexed susceptibility, and thus early maturing individuals were affected more by their environment in a "for better and for worse" manner. The sample consisted of 411 community-recruited youth aged 11-12 years (51% boys, 80% African Americans). Participants reported Tanner Stages of pubertal development, aggressive behavior and harsh parenting practice of their parents. Puberty scores were standardized with groups of the same age, sex, and ethnicity, and those that scored the top one-third were defined as early maturing individuals. Parents reported youth's aggressive behavior and their parenting practices towards the youth, including harsh parenting and positive parenting. Early pubertal timing significantly moderated the relationship between harsh/positive parenting and aggressive behavior. Specifically, harsh parenting was positively associated with aggressive behavior to a larger degree among early maturing individuals than among on-time/late-maturing individuals. Positive parenting was inversely associated with aggressive behavior but only among early maturing individuals. This study is the first to document support for early pubertal timing as susceptibility to the environmental influences in relation to aggressive behavior. Theoretical and intervention implications are discussed. © 2017 Wiley Periodicals, Inc.

  2. The Moderating Effects of Pubertal Timing on the Longitudinal Associations between Parent-Child Relationship Quality and Adolescent Substance Use

    Science.gov (United States)

    Shelton, Katherine H.; Van Den Bree, Marianne B. M.

    2010-01-01

    This prospective, longitudinal study investigated the moderating role of pubertal timing on reciprocal links between adolescent appraisals of parent-child relationship quality and girls' (N = 1,335) and boys' (N = 1,203) cigarette and alcohol use across a 12-month period. Reciprocal effects were found between parent-child relations and on-time…

  3. Peer substance use as a mediator between early pubertal timing and adolescent substance use: longitudinal associations and moderating effect of maltreatment.

    Science.gov (United States)

    Negriff, Sonya; Trickett, Penelope K

    2012-11-01

    Early pubertal timing has received considerable empirical support as a risk for adolescent substance use. However, few studies have examined the mediators linking these variables. Therefore, the aims of this study were (1) to examine peer substance use as a mediator between pubertal timing and adolescent substance use longitudinally and (2) to test gender and maltreatment experience as moderators of the mediational model. Data were obtained from time 1, 2, and 3 of a longitudinal study of maltreatment and development. At time 1 the sample was comprised of 303 maltreated and 151 comparison children aged 9-13 years (213 females and 241 males). Longitudinal mediation was tested using structural equation modeling and moderating effects were tested using multiple group analysis. Peer substance use mediated the relationship between early pubertal timing and later adolescent substance use for the total sample. Moderation analyses indicated this significant indirect effect did not differ for males and females. However, it did differ for maltreated versus comparison adolescents with the mediational effect only remaining significant for the comparison group. This is one of the first studies to examine peer substance use as a mediator of pubertal timing and adolescent substance use using a longitudinal design. Early maturing males are at equal risk to early maturing females for interacting with peers that may draw them into substance use. Additionally, the findings indicate that while peers are mediators for comparison adolescents a different mechanism may link early puberty to substance use for maltreated adolescents. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  4. Pubertal Timing and Mexican-Origin Girls’ Internalizing and Externalizing Symptoms: The Influence of Harsh Parenting

    Science.gov (United States)

    Deardorff, J.; Cham, H.; Gonzales, NA.; White, R.M.B.; Tein, J.-Y.; Wong, J.; Roosa, M.W.

    2012-01-01

    Early-maturing girls are at risk for internalizing and externalizing problems. Scarce research has examined pubertal timing and mental health among Mexican Americans, or examined the influence of parenting behaviors on these relations. This study addressed these gaps. This was a prospective examination of 362 Mexican-origin girls and their mothers using three waves of data. Measures included girls’ self-report of pubertal development and girls’ and mothers’ report of maternal harsh parenting and daughters’ mental health. Using structural equation modeling, we examined whether pubertal timing in 5th grade predicted girls’ internalizing and externalizing outcomes in 10th grade. We also examined the mediating and moderating effects of harsh parenting on the relations between pubertal timing and internalizing and externalizing behaviors, as well as the influence of mothers’ and daughters’ nativity on these relations. Results differed depending on reporter and maternal nativity. Using daughters’ report, Mexican American mothers’ harsh parenting acted as a moderator. At high levels of harsh parenting, early pubertal timing predicted higher externalizing scores, while at low levels of harsh parenting, early timing predicted lower externalizing scores. For Mexican immigrant mothers, harsh parenting mediated the effects of pubertal timing on girls’ internalizing and externalizing problems. There were no significant pubertal effects for mothers’ report. Findings suggest that maternal harsh parenting plays a key role in the relations between early pubertal timing and behavioral and emotional outcomes among Mexican-origin girls. PMID:23231686

  5. The Effects of Pubertal Timing on Body Image, School Behavior, and Deviance.

    Science.gov (United States)

    Duncan, Paula Duke; And Others

    1985-01-01

    Data from the National Health Examination Survey, a national probability sample of children and youth aged 12-17, was used to investigate the relationships between maturational timing and body image, school behavior, and deviance. (Author/LMO)

  6. Pubertal timing and adolescent sexual behavior in girls.

    Science.gov (United States)

    Moore, Sarah R; Harden, K Paige; Mendle, Jane

    2014-06-01

    Girls who experience earlier pubertal timing relative to peers also exhibit earlier timing of sexual intercourse and more unstable sexual relationships. Although pubertal development initiates feelings of physical desire, the transition into romantic and sexual relationships involves complex biological and social processes contributing both to physical maturation and to individual interpretations of pubertal experiences. Using a sample of female sibling pairs (n = 923 pairs) from the National Longitudinal Study of Adolescent Health, the present study investigated associations among menarche and perceived pubertal timing, age of first sexual intercourse (AFI), and adolescent dating and sexual behavior using a behavioral genetic approach. Genetic factors influencing age at menarche and perceived pubertal timing predicted AFI through shared genetic pathways, whereas genetic factors related only to perceived pubertal timing predicted engagement in dating, romantic sex, and nonromantic sex in the previous 18 months. These results suggest that a girl's interpretation of her pubertal timing beyond objective timing is important to consider for the timing and the contexts of romantic and reproductive behavior. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  7. Longitudinal Effects of Self-Report Pubertal Timing and Menarcheal Age on Adolescent Psychological and Behavioral Outcomes in Female Youths from Northern Taiwan.

    Science.gov (United States)

    Lee, Chih-Ting; Tsai, Meng-Che; Lin, Chung-Ying; Strong, Carol

    2017-08-01

    Early puberty is linked to adverse developmental outcomes in adolescents in Western societies. However, little is known about this relationship in an East Asian context. In addition, whether the impact of subjective pubertal timing (PT) and menarcheal age (MA) on adolescent psychosocial development persists into early adulthood remains unclear and is worthy of investigation. A subset of data was retrieved from the Taiwan Youth Project, which recruited and followed a longitudinal cohort of 7 th - and 9 th -grade female Taiwanese students from 2000 to 2007. Subjective PT was defined using the Pubertal Developmental Scale (PDS), which mainly measures pubertal changes. MA was recalled by participants themselves. Various psychological and behavioral factors were recorded and measured until the age of 20, including the use of alcohol and cigarettes, psychological well-being, sexual activity, and socially problematic behaviors. A χ 2 test for linear-by-linear association and one-way analysis of variance followed by multivariate regression models were used to dissect the differential effects of PT and MA in the association with the outcome variables. In total, 1545 female participants with an average age of 14.5 (±1.1) years were deemed valid for analysis. Among them, 257 (16.6%) participants perceived themselves as having early PT, defined as more than 1 standard deviation above the mean PDS score, and 82 (5.3%) had early MA (occurring before the 4 th grade). In univariate analysis, participants with early PT had higher rates of smoking and sexual activity, and MA was not related to their psychobehavioral outcomes. After multivariate adjustment, only late PT was significantly correlated with lower amounts of cigarette smoking and sexual activity before the age of 20. Conceptual and actual pubertal developments may be differentially associated with psychobehavioral outcomes among young Taiwanese girls. Clinical attention should be given to adolescent self-perception of

  8. Pubertal development timing in urban Chinese boys.

    Science.gov (United States)

    Ma, H-M; Chen, S-K; Chen, R-M; Zhu, C; Xiong, F; Li, T; Wang, W; Liu, G-L; Luo, X-P; Liu, L; Du, M-L

    2011-10-01

    We describe current pubertal development in healthy urban Chinese boys. A cross-sectional study of the pubertal development of 18,807 urban Chinese boys aged from 3.50 to 18.49years was conducted between 2003 and 2005. Testicular volume was evaluated with a Prader orchidometer. Pubic hair development was assessed according to the Tanner method. Data on spermarche were collected using the status quo method. Probit analysis was used to calculate the median age and 95% CI at different stages of testicular development, pubic hair development and spermarche. By age 9, 12.99% of the boys had a testicular volume of 4mL or greater. The median age of onset of puberty defined as the age at attainment of testicular volume of 4mL or greater was 10.55 (95% CI 10.27-10.79) years. The median age for onset of pubic hair development (PH(2) ) and spermarche was 12.78 (95%CI 12.67-12.89) years and 14.05 (95%CI 13.80-14.32) years, respectively. Pubertal onset in urban Chinese boys is earlier than currently used clinical norms but their pubic hair development occurs relatively late in comparison with the reported data from numerous other countries. There is also evidence of a secular trend towards an earlier age of spermarche since 1979 in Chinese urban boys. © 2011 The Authors. International Journal of Andrology © 2011 European Academy of Andrology.

  9. Gene-Environment Interplay in the Association between Pubertal Timing and Delinquency in Adolescent Girls

    Science.gov (United States)

    Harden, K. Paige; Mendle, Jane

    2014-01-01

    Early pubertal timing places girls at elevated risk for a breadth of negative outcomes, including involvement in delinquent behavior. While previous developmental research has emphasized the unique social challenges faced by early maturing girls, this relation is complicated by genetic influences for both delinquent behavior and pubertal timing, which are seldom controlled for in existing research. The current study uses genetically informed data on 924 female-female twin and sibling pairs drawn from the National Longitudinal Study of Adolescent Health to (1) disentangle biological versus environmental mechanisms for the effects of early pubertal timing and (2) test for gene-environment interactions. Results indicate that early pubertal timing influences girls’ delinquency through a complex interplay between biological risk and environmental experiences. Genes related to earlier age at menarche and higher perceived development significantly predict increased involvement in both non-violent and violent delinquency. Moreover, after accounting for this genetic association between pubertal timing and delinquency, the impact of non-shared environmental influences on delinquency are significantly moderated by pubertal timing, such that the non-shared environment is most important among early maturing girls. This interaction effect is particularly evident for non-violent delinquency. Overall, results suggest early maturing girls are vulnerable to an interaction between genetic and environmental risks for delinquent behavior. PMID:21668078

  10. The effect of tamoxifen on pubertal bone development in adolescents with pubertal gynecomastia.

    Science.gov (United States)

    Akgül, Sinem; Derman, Orhan; Kanbur, Nuray

    2016-01-01

    During puberty, estrogen has a biphasic effect on epiphyses; at low levels, it leads to an increase in height and bone mass, whereas at high levels, it leads to closure of the epiphysis. Tamoxifen is a selective estrogen receptor modulator that has been used in the treatment of pubertal gynecomastia. Although it has not been approved for this indication, studies have shown it to be both successful and safe. In males, the peak of pubertal bone development occurs during Tanner stage 3-4, which is also when pubertal gynecomastia reaches its highest prevalence. Thus tamoxifen treatment could potentially effect pubertal bone development. The aim of this study was to assess the effects of tamoxifen on bone mineral density (BMD) and skeletal maturation when used for pubertal gynecomastia. We evaluated 20 boys with pubertal gynecomastia receiving tamoxifen for at least 4 months. BMD was measured with dual-energy X-ray absorptiometry. Z-score and absolute BMD (g/cm(2)) was determined at baseline and 2 months after completing tamoxifen treatment. Bone age and height was evaluated before treatment and again one year later. Using absolute BMD (g/cm(2)), the mean difference from baseline was significant between the two groups both at spine (p=0.002) and femur (p=0.001), but not with the Z-score. This result was attributed to the expected increase during puberty according to sex and age. No significant effect on skeletal maturation was found (p=1.112). We conclude that when pubertal bone development is concerned, tamoxifen is safe for the treatment of pubertal gynecomastia as neither bone mineralization nor growth potential was affected.

  11. The influence of pubertal timing and stressful life events on depression and delinquency among Chinese adolescents.

    Science.gov (United States)

    Chen, Jie; Yu, Jing; Wu, Yun; Zhang, Jianxin

    2015-06-01

    This study aimed to investigate the influences of pubertal timing and stressful life events on Chinese adolescents' depression and delinquency. Sex differences in these influences were also examined. A large sample with 4,228 participants aged 12-15 years (53% girls) was recruited in Beijing, China. Participants' pubertal development, stressful life events, depressive symptoms, and delinquency were measured using self-reported questionnaires. Both early maturing girls and boys displayed more delinquency than their same-sex on-time and late maturing peers. Early maturing girls displayed more depressive symptoms than on-time and late maturing girls, but boys in the three maturation groups showed similar levels of depressive symptoms. The interactive effects between early pubertal timing and stressful life events were significant in predicting depression and delinquency, particularly for girls. Early pubertal maturation is an important risk factor for Chinese adolescents' depression and delinquency. Stressful life events intensified the detrimental effects of early pubertal maturation on adolescents' depression and delinquency, particularly for girls. © 2015 The Institute of Psychology, Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

  12. Pubertal timing and early sexual intercourse in the offspring of teenage mothers.

    Science.gov (United States)

    De Genna, Natacha M; Larkby, Cynthia; Cornelius, Marie D

    2011-10-01

    Early puberty is associated with stressful family environments, early sexual intercourse, and teenage pregnancy. We examined pubertal timing and sexual debut among the 14-year-old offspring of teenage mothers. Mothers (71% Black, 29% White) were recruited as pregnant teenagers (12-18 years old). Data were collected during pregnancy and when offspring were 6, 10 and 14 years old (n = 318). Adolescents (50% male) compared the timing of their pubertal maturation to same-sex peers. There was a significant 3-way interaction effect of race, sex, and pubertal timing on sexual debut (n = 305). This effect remained significant in a model controlling for maternal age at first intercourse, substance use, exposure to trauma, authoritative parenting, and peer sexual activity (n = 255). Early maturation was associated with early sex in daughters, and may be one pathway for the inter-generational transfer of risk for teenage pregnancy among daughters of teenage mothers.

  13. Association Between Urinary Phthalates and Pubertal Timing in Chinese Adolescents

    Directory of Open Access Journals (Sweden)

    Huijing Shi

    2015-09-01

    Full Text Available Background: Phthalates are synthetic chemicals and ubiquitous environmental contaminants, with hormonal activity that may alter the course of pubertal development in children. Objectives: To determine whether exposure to phthalate metabolites is associated with timing of pubertal development in a cross-sectional study of a school-based clustered sample of 503 children from a suburban district in Shanghai, China, who were 7–14 years of age at enrollment (2010 October to November. Methods: We analyzed six phthalate metabolites in urine samples by isotope-dilution liquid chromatography tandem mass spectrometry. The associations of exposures to phthalates with pubertal timing of testes, breast, and pubic hair development (represented as Tanner stages were evaluated using an ordered logistic regression model adjusted for chronological age, body fat proportion (BF%, and parental education. Results: In boys, urinary mono-n-butyl phthalate (MBP levels were negatively associated with testicular volume, and mono (2-ethyl-5-hydroxyhexyl phthalate (MEHHP and mono (2-ethyl-5-oxohexyl phthalate (MEOHP levels were negatively associated with pubic hair stages. The odds of being in an advanced stage were decreased by 43%–51%. In girls, mono (2-ethylhexyl phthalate (MEHP, MEHHP, and MEOHP levels, as well as the sum of these levels, were positively associated with breast stages, and the association was much stronger in girls with high BF%; the odds of being in an advanced stage were increase by 29% to 50%. Conclusions: Phthalate metabolites investigated in this study show significant associations with pubertal timing both in boys and in girls, especially among girls with high BF%.

  14. Patterns and correlates of pubertal development in Canadian youth: effects of family context.

    Science.gov (United States)

    Arim, Rubab G; Shapka, Jennifer D; Dahinten, V Susan; Willms, J Douglas

    2007-01-01

    Current health literature suggests that there has been a decline in the age of pubertal onset, and that pubertal development is influenced by social context. Unfortunately, contemporary Canadian-specific data have not been available. This study examined the odds of having entered puberty at various ages during adolescence, before and after controlling for the effects of family socio-economic status and family structure. Longitudinal data for this study were drawn from the first four cycles of the National Longitudinal Survey of Children and Youth. The final sample consisted of 7977 adolescents ranging in age from 10 to 17. Pubertal status of the participants was identified based on pubic hair, facial hair growth, and voice change, for boys; and pubic hair, breast development, and menstruation, for girls. Trajectories of pubertal development were analyzed with HLM growth curve modelling techniques. The results indicated that, compared to boys, the odds of having entered puberty at age 13 were 6.45 times higher for girls and that girls go through puberty more quickly. Low family socio-economic status and living with a stepfather were found to predict early onset of pubertal development. Contextual factors are related to pubertal development. Additional research is needed to develop a more solid understanding of how psychosocial factors interact to predict gendered patterns of pubertal development.

  15. Role of amygdala kisspeptin in pubertal timing in female rats.

    Directory of Open Access Journals (Sweden)

    Daniel A Adekunbi

    Full Text Available To investigate the mechanism by which maternal obesity disrupts reproductive function in offspring, we examined Kiss1 expression in the hypothalamic arcuate (ARC and anteroventral periventricular (AVPV nuclei, and posterodorsal medial amygdala (MePD of pre-pubertal and young adult offspring. Sprague-Dawley rats were fed either a standard or energy-dense diet for six weeks prior to mating and throughout pregnancy and lactation. Male and female offspring were weaned onto normal diet on postnatal day (pnd 21. Brains were collected on pnd 30 or 100 for qRT-PCR to determine Kiss1 mRNA levels. Maternal obesity increased Kiss1 mRNA expression in the MePD of pre-pubertal male and female offspring, whereas Kiss1 expression was not affected in the ARC or AVPV at this age. Maternal obesity reduced Kiss1 expression in all three brain regions of 3 month old female offspring, but only in MePD of males. The role of MePD kisspeptin on puberty, estrous cyclicity and preovulatory LH surges was assessed directly in a separate group of post-weanling and young adult female rats exposed to a normal diet throughout their life course. Bilateral intra-MePD cannulae connected to osmotic mini-pumps for delivery of kisspeptin receptor antagonist (Peptide 234 for 14 days were chronically implanted on pnd 21 or 100. Antagonism of MePD kisspeptin delayed puberty onset, disrupted estrous cyclicity and reduced the incidence of LH surges. These data show that the MePD plays a key role in pubertal timing and ovulation and that maternal obesity may act via amygdala kisspeptin signaling to influence reproductive function in the offspring.

  16. Ethnicity, Perceived Pubertal Timing, Externalizing Behaviors, and Depressive Symptoms among Black Adolescent Girls

    Science.gov (United States)

    Carter, Rona; Caldwell, Cleopatra Howard; Matusko, Niki; Antonucci, Toni; Jackson, James S.

    2011-01-01

    An accumulation of research evidence suggests that early pubertal timing plays a significant role in girls' behavioral and emotional problems. If early pubertal timing is a problematic event, then early developing Black girls should manifest evidence of this crisis because they tend to be the earliest to develop compared to other girls from…

  17. The Role of Peer Stress and Pubertal Timing on Symptoms of Psychopathology during Early Adolescence

    Science.gov (United States)

    Sontag, Lisa M.; Graber, Julia A.; Clemans, Katherine H.

    2011-01-01

    Stress is known to amplify the link between pubertal timing and psychopathology. However, few studies have examined the role of peer stress as a context for this link. The present study examined the interaction between perceived pubertal timing and peer stress on symptoms of psychopathology in early adolescence. The sample consisted of 264…

  18. Recent changes in pubertal timing in healthy Danish boys

    DEFF Research Database (Denmark)

    Sørensen, K; Aksglæde, Lise; Petersen, Jørgen Holm

    2010-01-01

    In the 1990s, the American population-based study NHANES III renewed the focus on possible secular trends in male puberty. However, no conclusions could be made on pubertal onset due to the lack of compatible data.......In the 1990s, the American population-based study NHANES III renewed the focus on possible secular trends in male puberty. However, no conclusions could be made on pubertal onset due to the lack of compatible data....

  19. Off-Time Pubertal Timing Predicts Physiological Reactivity to Postpuberty Interpersonal Stress

    Science.gov (United States)

    Smith, Anne Emilie; Powers, Sally I.

    2009-01-01

    We investigated associations between retrospectively assessed timing of pubertal development, interpersonal interactions, and hypothalamic-pituitary-adrenal axis reactivity to an interpersonal stress task in 110 young adult women. Participants provided salivary cortisol samples at points prior and subsequent to a video-taped conflict discussion…

  20. Sex 'n' drugs 'n' rock 'n' roll: the meaning and social consequences of pubertal timing.

    Science.gov (United States)

    Waylen, Andrea; Wolke, Dieter

    2004-11-01

    This is a brief review of the normal changes in adolescent behaviour and the interplay between biology and social factors that occur at and around puberty, in an attempt to explain when this transition may become problematic The onset of puberty is a biological marker for an individual's transition from a non-reproductive to a reproductive state. Adolescence is a normal developmental transition associated with clearly visible physical changes, reorganization and pruning of neuronal circuits in the brain and the occurrence of new behaviours and interests. It is a time when new life tasks (orientation towards peers of the other sex, romantic and sexual involvement and mastering an educational career) need to be mastered. Parent-child conflict increases and becomes more intense as the adolescent struggles for more independence while still requiring support. These normal changes can become problematic if biological and social expectations diverge e.g. entering puberty very early or very late. While early pubertal onset in boys is likely to have beneficial effects, in girls precocious pubertal timing may have a negative impact on body-image, affect (or emotional well-being) and sex-role expectations. Other individual biological predispositions and genetic endowment may interact with social factors (e.g. peers, parenting style, neighbourhood) making adolescence either an adaptive or a challenging transition. There is a lack of sufficiently large longitudinal studies that have been able to study this interaction between genetics, biology and social environment on adolescent development. The Avon Longitudinal Study of Parents and Children (ALSPAC) cohort provides a unique opportunity to investigate the impact of pubertal timing on social behaviour. Planned assessments and concepts are outlined.

  1. Pubertal Timing and Youth Internalizing Psychopathology: The Role of Relational Aggression.

    Science.gov (United States)

    Pomerantz, Hayley; Parent, Justin; Forehand, Rex; Breslend, Nicole Lafko; Winer, Jeffrey P

    2017-02-01

    The current study examined relational aggression as a potential mechanism that explains the association between off-time pubertal development and internalizing problems in youth. Youth gender was also examined as a moderator for the association between these variables. It was hypothesized that early pubertal maturation would be associated with higher levels of relationally aggressive behavior which, in turn, would be associated with elevated levels of internalizing problems. Parents of 372 children between the ages of 8 and 17 were recruited through Amazon's Mechanical Turk. Parents responded to demographic information about themselves, as well as information about their child's pubertal timing, relationally aggressive behavior, and anxiety and depressive symptoms. Findings indicated that early pubertal timing was associated with higher levels of anxiety directly, and higher levels of both anxiety and depressive symptoms indirectly through higher levels of relational aggression. In all but one of the pathways examined, gender was not found to moderate the associations between the study variables of interest. This study is the first to examine relational aggression as a mechanism by which early pubertal timing leads to internalizing problems. The findings suggest that relational aggression could be a target for intervention among early developing youth who are at risk for internalizing problems.

  2. Pubertal timing and substance use: associations between and within families across late adolescence.

    Science.gov (United States)

    Dick, D M; Rose, R J; Viken, R J; Kaprio, J

    2000-03-01

    In the present study, between-family analyses of data from adolescent twin girls offer new evidence that early menarche is associated with earlier initiation and greater frequency of smoking and drinking. The role of personality factors and peer relationships in that association was investigated, and little support was found for their involvement. Novel within-family analyses replicating associations of substance use with pubertal timing in contrasts of twin sisters selected for extreme discordance for age at menarche are reported. Within-family replications demonstrated that the association of pubertal timing with substance use cannot be explained solely by between-family confounds. Within-family analyses demonstrated contextual modulation of the influence of pubertal timing: Its impact on drinking frequency is apparent only among girls in urban settings. Sibling comparisons illustrate a promising analytic tool for studying diverse developmental outcomes.

  3. Pubertal Onset in Boys and Girls Is Influenced by Pubertal Timing of Both Parents

    DEFF Research Database (Denmark)

    Wohlfahrt-Veje, Christine; Mouritsen, Annette; Hagen, Casper P

    2016-01-01

    children in a longitudinal cohort study. Information on parental timing of puberty (earlier, comparable to, or later compared to peers) and menarche age was retrieved from questionnaires. PARTICIPANTS: A total of 672 girls and 846 boys. MAIN OUTCOME MEASURES: Age at onset of pubic hair (PH2+), breasts (B2...

  4. Pubertal Timing and Early Sexual Intercourse in the Offspring of Teenage Mothers

    Science.gov (United States)

    De Genna, Natacha M.; Larkby, Cynthia; Cornelius, Marie D.

    2011-01-01

    Early puberty is associated with stressful family environments, early sexual intercourse, and teenage pregnancy. We examined pubertal timing and sexual debut among the 14-year-old offspring of teenage mothers. Mothers (71% Black, 29% White) were recruited as pregnant teenagers (12-18 years old). Data were collected during pregnancy and when…

  5. Early Adolescent Boys' Exposure to Internet Pornography: Relationships to Pubertal Timing, Sensation Seeking, and Academic Performance

    Science.gov (United States)

    Beyens, Ine; Vandenbosch, Laura; Eggermont, Steven

    2015-01-01

    Research has demonstrated that adolescents regularly use Internet pornography. This two-wave panel study aimed to test an integrative model in early adolescent boys (M[subscript age] = 14.10; N = 325) that (a) explains their exposure to Internet pornography by looking at relationships with pubertal timing and sensation seeking, and (b) explores…

  6. Early adolescent boys’ exposure to Internet pornography: relationships to pubertal timing, sensation seeking, and academic performance

    NARCIS (Netherlands)

    Beyens, I.; Vandenbosch, L.; Eggermont, S.

    2015-01-01

    Research has demonstrated that adolescents regularly use Internet pornography. This two-wave panel study aimed to test an integrative model in early adolescent boys (Mage = 14.10; N = 325) that (a) explains their exposure to Internet pornography by looking at relationships with pubertal timing and

  7. Subjective Age in Early Adolescence: Relationships with Chronological Age, Pubertal Timing, Desired Age, and Problem Behaviors

    Science.gov (United States)

    Hubley, Anita M.; Arim, Rubab G.

    2012-01-01

    Subjective age generally refers to the age that one feels. In a cross-sectional questionnaire study of 245 adolescents ages 10-14 years, we examined (a) whether, and when, a cross-over in subjective age occurs, (b) differences in subjective age among pubertal timing groups, (c) correlations between subjective age and each of desired age and five…

  8. Pubertal Timing and Mexican-Origin Girls' Internalizing and Externalizing Symptoms: The Influence of Harsh Parenting

    Science.gov (United States)

    Deardorff, Julianna; Cham, Heining; Gonzales, Nancy A.; White, Rebecca M. B.; Tein, Jenn-Yun; Wong, Jessie J.; Roosa, Mark W.

    2013-01-01

    Early-maturing girls are at risk for internalizing and externalizing problems. Research concerning pubertal timing and mental health among Mexican Americans or the influence of parenting behaviors on these relations has been scarce. This study addressed these gaps. This was a prospective examination of 362 Mexican-origin girls and their mothers in…

  9. The value of shoe size for prediction of the timing of the pubertal growth spurt.

    NARCIS (Netherlands)

    Busscher, I.; Kingma, I.; Wapstra, F.H.; Bulstra, S.K.; Verkerke, G.J.; Veldhuizen, A.G.

    2011-01-01

    Background: Knowing the timing of the pubertal growth spurt of the spine, represented by sitting height, is essential for the prognosis and therapy of adolescent idiopathic scoliosis. There are several indicators that reflect growth or remaining growth of the patient. For example, distal body parts

  10. Coming of age in Roman Britain: Osteological evidence for pubertal timing.

    Science.gov (United States)

    Arthur, Nichola A; Gowland, Rebecca L; Redfern, Rebecca C

    2016-04-01

    Puberty is a key transitional phase of the human life course, with important biological and social connotations. Novel methods for the identification of the pubertal growth spurt and menarche in skeletal remains have recently been proposed (Shapland and Lewis, 2013, 2014). In this study we applied the methods to two Romano-British cemetery samples (1st-early 5th centuries AD) in order to investigate the timing of puberty during this period and further assess the veracity of the methods. Shapland and Lewis' methods (2013, 2014) were applied to 38 adolescents (aged 8-20 years) from the British cemetery sites of Roman London (1st-early 5th centuries AD) and Queenford Farm, Oxfordshire (4th-early 5th centuries AD). Overall, the Romano-British males and females experienced the onset of puberty at similar ages to modern European adolescents, but subsequently experienced a longer period of pubertal development. Menarche occurred between the ages of 15 and 17 years for these Romano-British females, around 2 to 4 years later than for present-day European females. The observed Romano-British pattern of pubertal timing has various possible explanations, including exposure to environmental stressors in early urban environments. The pattern of pubertal timing is largely congruent with social age transitions alluded to in ancient texts and funerary evidence for this period. While there are limitations to the application of these techniques to archaeological samples, they were successfully applied in this study, and may have important implications for understandings of past life courses, as well as providing a long-term perspective on pubertal timing and biocultural interactions. © 2016 Wiley Periodicals, Inc.

  11. Genome-wide association and longitudinal analyses reveal genetic loci linking pubertal height growth, pubertal timing and childhood adiposity

    NARCIS (Netherlands)

    Cousminer, Diana L.; Berry, Diane J.; Timpson, Nicholas J.; Ang, Wei; Thiering, Elisabeth; Byrne, Enda M.; Taal, H. Rob; Huikari, Ville; Bradfield, Jonathan P.; Kerkhof, Marjan; Groen-Blokhuis, Maria M.; Kreiner-Moller, Eskil; Marinelli, Marcella; Holst, Claus; Leinonen, Jaakko T.; Perry, John R. B.; Surakka, Ida; Pietilainen, Olli; Kettunen, Johannes; Anttila, Verneri; Kaakinen, Marika; Sovio, Ulla; Pouta, Anneli; Das, Shikta; Lagou, Vasiliki; Power, Chris; Prokopenko, Inga; Evans, David M.; Kemp, John P.; St Pourcain, Beate; Ring, Susan; Palotie, Aarno; Kajantie, Eero; Osmond, Clive; Lehtimaki, Terho; Viikari, Jorma S.; Kahonen, Mika; Warrington, Nicole M.; Lye, Stephen J.; Palmer, Lyle J.; Tiesler, Carla M. T.; Flexeder, Claudia; Montgomery, Grant W.; Medland, Sarah E.; Hofman, Albert; Hakonarson, Hakon; Guxens, Monica; Bartels, Meike; Salomaa, Veikko; Koppelman, Gerard H.

    2013-01-01

    The pubertal height growth spurt is a distinctive feature of childhood growth reflecting both the central onset of puberty and local growth factors. Although little is known about the underlying genetics, growth variability during puberty correlates with adult risks for hormone-dependent cancer and

  12. A Twin Study of Objective and Subjective Pubertal Timing and Peer Influence on Risk-Taking.

    Science.gov (United States)

    Kretsch, Natalie; Mendle, Jane; Harden, K Paige

    2016-03-01

    The current study used a behavioral genetic design to test whether three measures of pubertal timing moderated peer influence on risk-taking in a sample of 248 female adolescent twin pairs ( M age =16.0, SD =1.5) from the National Longitudinal Study of Adolescent Health. Peer influence was operationalized as the quasi-causal association between girls' self-reported risk-taking and the risk-taking reported by their friends. Girls with earlier ages at menarche and who perceived themselves as more developed than peers were more susceptible to peer influence on risk-taking. However, age-standardized ratings of body changes did not moderate peer influence. This study highlights distinctions between multiple measures of pubertal timing, using an innovative synthesis of genetically informative data and peer nomination data.

  13. Sex variations in youth anxiety symptoms: effects of pubertal development and gender role orientation.

    Science.gov (United States)

    Carter, Rona; Silverman, Wendy K; Jaccard, James

    2011-01-01

    This study evaluated whether pubertal development and gender role orientation (i.e., masculinity and femininity) can partially explain sex variations in youth anxiety symptoms among clinic-referred anxious youth (N = 175; ages 9-13 years; 74% Hispanic; 48% female). Using youth and parent ratings of youth anxiety symptoms, structural equation modeling results indicated that youth who reported being more advanced in their pubertal development reported high levels of femininity and anxiety symptoms. Youth who reported high levels of masculinity had low levels of anxiety symptoms as reported by both youths and parents. The estimated effects of pubertal development, femininity, and masculinity on youth and parent ratings of youth anxiety symptoms were not significantly moderated by biological sex. Pubertal development and gender role orientation appear to be important in explaining levels of youth anxiety symptoms among clinic-referred anxious youth.

  14. Understanding the Link Between Pubertal Timing in Girls and the Development of Depressive Symptoms: The Role of Sexual Harassment.

    Science.gov (United States)

    Skoog, Therése; Bayram Özdemir, Sevgi; Stattin, Håkan

    2016-02-01

    The link between sexual maturation, or pubertal timing, in girls and adolescent depressive symptoms is well-documented, but the underlying processes remain unclear. We examined whether sexual harassment, which has previously been linked to both pubertal timing and depressive symptoms, mediates this link, using a two-wave longitudinal study including 454 girls in 7th (M age  = 13.42, SD = .53) and 8th grade (M age  = 14.42, SD = .55). Pubertal timing was linked to depressive symptoms in both age groups, and predicted an increase in depressive symptoms among the 7th graders. Sexual harassment significantly mediated the link between pubertal timing and depressive symptoms among the 7th, but not the 8th grade girls. Together, our findings suggest that one way to prevent depressive symptoms among early-maturing girls could be to address sexual harassment in preventive intervention in early adolescence.

  15. Effects of prenatal exposure to a low dose atrazine metabolite mixture on pubertal timing and prostate development of male Long-Evans rats

    Energy Technology Data Exchange (ETDEWEB)

    Stanko, Jason [National Institute of Environmental Health Sciences (NIEHS); Enoch, Rolondo [North Carolina Central University, Durham; Rayner, Jennifer L [ORNL; Davis, Christine [U.S. Environmental Protection Agency; Wolf, Douglas [U.S. Environmental Protection Agency; Malarkey, David [University of North Carolina, Chapel Hill; Fenton, Suzanne [National Institute of Environmental Health Sciences (NIEHS)

    2010-12-01

    The present study examines the postnatal reproductive development of male rats following prenatal exposure to an atrazine metabolite mixture (AMM) consisting of the herbicide atrazine and its environmental metabolites diaminochlorotriazine, hydroxyatrazine, deethylatrazine, and deisopropylatrazine. Pregnant Long-Evans rats were treated by gavage with 0.09, 0.87, or 8.73 mg AMM/kg body weight (BW), vehicle, or 100 mg ATR/kg BW positive control, on gestation days 15 19. Preputial separation was significantly delayed in 0.87 mg and 8.73 mg AMM-exposed males. AMM-exposed males demonstrated a significant treatment-related increase in incidence and severity of inflammation in the prostate on postnatal day (PND) 120. A dose-dependent increase in epididymal fat masses and prostate foci were grossly visible in AMM-exposed offspring. These results indicate that a short, late prenatal exposure to mixture of chlorotriazine metabolites can cause chronic prostatitis in male LE rats. The mode of action for these effects is presently unclear.

  16. Effects of programmed physical activity on body composition in post-pubertal schoolchildren

    Directory of Open Access Journals (Sweden)

    Edson dos Santos Farias

    2015-04-01

    Full Text Available OBJECTIVE: To assess body composition modifications in post-pubertal schoolchildren after practice of a physical activity program during one school year. METHODS: The sample consisted of 386 students aged between 15 and 17 years and divided into two groups: the study group (SG comprised 195 students and the control group (CG, 191. The SG was submitted to a physical activity program and the CG attended conventional physical education classes. Body composition was assessed using body mass index (BMI, percentage of body fat (%BF, fat mass (FM, and lean mass (LM. RESULTS: A positive effect of the physical activity program on body composition in the SG (p < 0.001 was observed, as well as on the interaction time x group in all the variables analyzed in both genders. A reduction in %BF (mean of differences = -5.58% and waist circumference (-2.33 cm, as well as an increase in LM (+2.05 kg were observed in the SG for both genders, whereas the opposite was observed in the CG. CONCLUSION: The practice of programmed physical activity promotes significant reduction of body fat in post-pubertal schoolchildren.

  17. The Interaction Between Pubertal Timing and Peer Popularity for Boys and Girls: An Integration of Biological and Interpersonal Perspectives on Adolescent Depression.

    Science.gov (United States)

    Teunissen, Hanneke A; Adelman, Caroline B; Prinstein, Mitchell J; Spijkerman, Renske; Poelen, Evelien A P; Engels, Rutger C M E; Scholte, Ron H J

    2011-04-01

    The transition to adolescence marks a time of sharply increased vulnerability to the development of depression, particularly among girls. Past research has examined isolated risk factors from individual theoretical models (e.g., biological, interpersonal, and cognitive) of depression, but few have examined integrative models. This study investigated the conjoint effects of early pubertal timing and popularity in the longitudinal prediction of depressive symptoms. A total of 319 girls and 294 boys (ages 11-14) provided information on their pubertal status, depressive symptoms, and the social status (i.e., popularity) of their peers. Adolescents completed a second measure of depressive symptoms 11 months after the initial time point. Findings supported an integrated biological-interpersonal model in explaining the development of depressive symptoms during adolescence. Early pubertal development was associated with increase in depressive symptoms only when accompanied by low levels of popularity. High levels of popularity buffered the association between early pubertal development and later depressive symptoms. Unexpectedly, these results were significant both for girls and boys. Results are discussed in terms of dynamic systems theories.

  18. Role Of Serum Lectin In Derangement Of PUBERTAL Timing In Thalassaemic Patients

    International Nuclear Information System (INIS)

    MOAWAD, A.T.; NASSAR, E.M.; EL-NASHAR, N.A.

    2010-01-01

    patients with delayed puberty. Serum leptin levels showed a negative correlation with ferritin levels and positive correlations with each of serum FSH, LH and testosterone in males and estradiol in females in both patients groups. It could be concluded that adipose tissue dysfunction, due to iron overload, could be considered as one of the endocrinopathies affecting thalassaemic patients. The consequent low leptin levels might be a cofactor in the derangement of pubertal timing observed in thalassaemic patients at puberty which necessitates newer protocols of treatment, correct blood transfusion and chelation therapy.

  19. Effects of Di-(2-ethylhexyl Phthalate on the Hypothalamus–Uterus in Pubertal Female Rats

    Directory of Open Access Journals (Sweden)

    Te Liu

    2016-11-01

    Full Text Available The pollution of endocrine disruptors and its impact on human reproductive system have attracted much attention. Di-(2-ethylhexyl phthalate (DEHP, an environmental endocrine disruptor, is widely used in food packages, containers, medical supplies and children’s toys. It can cause diseases such as infertility, sexual precocity and uterine bleeding and thus arouse concerns from the society and scholars. The effect of DEHP on pubertal female reproductive system is still not well-studied. This study was to investigate the effects of DEHP on the hypothalamus–uterus in pubertal female rats, reveal the reproductive toxicity of DEHP on pubertal female rats and its mechanism, and provide scientific evidence for the evaluation of toxicity and toxic mechanism of DEHP on reproductive system. Forty-eight pubertal female rats were randomly divided into four groups and respectively administered via oral gavage 0, 250, 500, or 1000 mg/kg/d DEHP in 0.1 mL corn oil/20 g body weight for up to four weeks. Compared with control rats, the DEHP-treated rats showed: (1 higher gonadotropin-releasing hormone (GnRH level in the hypothalamus; (2 higher protein levels of GnRH in the hypothalamus; and (3 higher mRNA and protein levels of GnRH receptor (GnRHR in the uterus. Our data reveal that DEHP exposure may lead to a disruption in pubertal female rats and an imbalance of hypothalamus–uterus. Meanwhile, DEHP may, through the GnRH in the hypothalamus and its receptor on the uterus, lead to diseases of the uterus. DEHP may impose a negative influence on the development and functioning of the reproductive system in pubertal female rats.

  20. Effects of Di-(2-ethylhexyl) Phthalate on the Hypothalamus–Uterus in Pubertal Female Rats

    Science.gov (United States)

    Liu, Te; Jia, Yiyang; Zhou, Liting; Wang, Qi; Sun, Di; Xu, Jin; Wu, Juan; Chen, Huaiji; Xu, Feng; Ye, Lin

    2016-01-01

    The pollution of endocrine disruptors and its impact on human reproductive system have attracted much attention. Di-(2-ethylhexyl) phthalate (DEHP), an environmental endocrine disruptor, is widely used in food packages, containers, medical supplies and children’s toys. It can cause diseases such as infertility, sexual precocity and uterine bleeding and thus arouse concerns from the society and scholars. The effect of DEHP on pubertal female reproductive system is still not well-studied. This study was to investigate the effects of DEHP on the hypothalamus–uterus in pubertal female rats, reveal the reproductive toxicity of DEHP on pubertal female rats and its mechanism, and provide scientific evidence for the evaluation of toxicity and toxic mechanism of DEHP on reproductive system. Forty-eight pubertal female rats were randomly divided into four groups and respectively administered via oral gavage 0, 250, 500, or 1000 mg/kg/d DEHP in 0.1 mL corn oil/20 g body weight for up to four weeks. Compared with control rats, the DEHP-treated rats showed: (1) higher gonadotropin-releasing hormone (GnRH) level in the hypothalamus; (2) higher protein levels of GnRH in the hypothalamus; and (3) higher mRNA and protein levels of GnRH receptor (GnRHR) in the uterus. Our data reveal that DEHP exposure may lead to a disruption in pubertal female rats and an imbalance of hypothalamus–uterus. Meanwhile, DEHP may, through the GnRH in the hypothalamus and its receptor on the uterus, lead to diseases of the uterus. DEHP may impose a negative influence on the development and functioning of the reproductive system in pubertal female rats. PMID:27845755

  1. Pubertal timing and health-related behaviours in adolescence - socio- economic outcomes in a follow-up study from Finland

    Directory of Open Access Journals (Sweden)

    Leena K Koivusilta

    2006-03-01

    Full Text Available

    Background. Pubertal timing is connected with health-related lifestyle in adulthood. We studied whether early or late pubertal timing is predictive of socio-economic outcomes in early adulthood and whether the associations are mediated by health behaviours.

    Methods. Survey data (1981, 1983, 1985, 1987 from samples of 14-year-old Finns (N=4246, response rate 85% were linked with respondents’ attained educational level, socio-economic and labour market position in 2001 (ages 28-34. Ages of menarche and first ejaculation indicated pubertal timing.

    Results. As compared to adolescents with average age pubertal timing, boys and girls maturing at an early age more often participated in health-compromising behaviours, while those maturing at a later age participated less frequently. Pubertal timing was not associated with attained educational level or socioeconomic position in girls and not with labour market position at the time of follow-up in either sex. In boys, independently of health behaviours, early or late onset of puberty predicted low educational level, while late onset predicted low socio-economic position.

    Conclusion. Timing of puberty has a stronger connection with socio-economic outcomes in boys than in girls. Deviance from the normative pace of physical development, especially late maturation, is among boys slightly depicted in the hierarchy of socio-economic positions of the society. As pubertal timing is connected with health-related behaviours – especially with smoking – the pacing of developmental transitions should be considered in planning programmes preventing unhealthy behavioural patterns often linked with negative attitudes towards schooling.

  2. EFFECTS OF DIBUTYL PHTHALATE IN MALE RABBITS FOLLOWING IN UTERO, ADOLESCENT OR POST-PUBERTAL EXPOSURE

    Science.gov (United States)

    Effects of dibutyl phthalate in male rabbits following in utero, adolescent, or post-pubertal exposureTy T. Higuchi1, Jennifer S. Palmer1, L. Earl Gray Jr2., and D. N. Rao Veeramachaneni11Animal Reproduction and Biotechnology Laboratory, Colorado State University, Fort

  3. Development and Lability in the Parent-Child Relationship During Adolescence: Associations With Pubertal Timing and Tempo

    Science.gov (United States)

    Marceau, Kristine; Ram, Nilam; Susman, Elizabeth

    2014-01-01

    Adolescents' and parents' reactions to pubertal development are hypothesized to contribute to changes in family dynamics. Using 7-year longitudinal data from the NICHD-SECCYD (488 boys, 475 girls) we examined relations between pubertal development (timing, tempo) and trajectories (developmental change and year-to-year lability) of parent-child conflict and closeness from age 8.5 to 15.5 years. Changes were mostly characterized by year-to-year fluctuations – lability. Parent-child conflict increased and closeness decreased some with age. Pubertal timing and tempo were more consistently associated with lability in parent-child relationships than with long-term trends, although faster tempo was associated with steeper decreases in parent-child closeness. Findings provide a platform for examining how puberty contributes to both long-term and transient changes in adolescents' relationships and adjustment. PMID:26321856

  4. Recent changes in pubertal timing in healthy Danish boys: associations with body mass index

    DEFF Research Database (Denmark)

    Sørensen, Kaspar; Aksglaede, Lise; Petersen, Jørgen Holm

    2010-01-01

    In the 1990s, the American population-based study NHANES III renewed the focus on possible secular trends in male puberty. However, no conclusions could be made on pubertal onset due to the lack of compatible data.......In the 1990s, the American population-based study NHANES III renewed the focus on possible secular trends in male puberty. However, no conclusions could be made on pubertal onset due to the lack of compatible data....

  5. Sexual differentiation of human behavior: effects of prenatal and pubertal organizational hormones.

    Science.gov (United States)

    Berenbaum, Sheri A; Beltz, Adriene M

    2011-04-01

    A key question concerns the extent to which sexual differentiation of human behavior is influenced by sex hormones present during sensitive periods of development (organizational effects), as occurs in other mammalian species. The most important sensitive period has been considered to be prenatal, but there is increasing attention to puberty as another organizational period, with the possibility of decreasing sensitivity to sex hormones across the pubertal transition. In this paper, we review evidence that sex hormones present during the prenatal and pubertal periods produce permanent changes to behavior. There is good evidence that exposure to high levels of androgens during prenatal development results in masculinization of activity and occupational interests, sexual orientation, and some spatial abilities; prenatal androgens have a smaller effect on gender identity, and there is insufficient information about androgen effects on sex-linked behavior problems. There is little good evidence regarding long-lasting behavioral effects of pubertal hormones, but there is some suggestion that they influence gender identity and perhaps some sex-linked forms of psychopathology, and there are many opportunities to study this issue. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Exposure to peer delinquency as a mediator between self-report pubertal timing and delinquency: A longitudinal study of mediation

    Science.gov (United States)

    Negriff, Sonya; Ji, Juye; Trickett, Penelope K.

    2013-01-01

    This study examined exposure to peer delinquency as a mediator between pubertal timing and self-reported delinquency longitudinally and whether this mediational model was moderated by either gender or maltreatment experience. Data were obtained from Time 1, 2, and 3 of a longitudinal study of maltreatment and development. At Time 1 the sample comprised 454 children aged 9–13 years. Analyses via structural equation modeling supported full mediation. Gender did not moderate this mediational relationship, but maltreatment experience did. The results show that early maturing males and females are both at risk for being exposed to peers that may draw them into delinquent behavior. Additionally, the mechanism linking early pubertal timing to delinquency differs depending on maltreatment experience. PMID:21262055

  7. Forty years trends in timing of pubertal growth spurt in 157,000 Danish school children

    DEFF Research Database (Denmark)

    Aksglæde, Lise; Olsen, Lina Wøhlk; Sørensen, Thorkild I.A.

    2008-01-01

    to 1969 who attended primary school in the Copenhagen Municipality. 135,223 girls and 21,612 boys fulfilled the criteria for determining age at OGS and age at PHV. These physiological events were used as markers of pubertal development in our computerized method in order to evaluate any secular trends...... in pubertal maturation during the study period (year of birth 1930 to 1969). In this period, age at OGS declined statistically significantly by 0.2 and 0.4 years in girls and boys, respectively, whereas age at PHV declined statistically significantly by 0.5 and 0.3 years in girls and boys, respectively...

  8. Peer and Individual Risk Factors in Adolescence Explaining the Relationship between Girls' Pubertal Timing and Teenage Childbearing

    Science.gov (United States)

    Hendrick, C. Emily; Cance, Jessica Duncan; Maslowsky, Julie

    2016-01-01

    Girls with early pubertal timing are at elevated risk for teenage childbearing; however, the modifiable mechanisms driving this relationship are not well understood. The objective of the current study was to determine whether substance use, perceived peer substance use, and older first sexual partners mediate the relationships among girls' pubertal timing, sexual debut, and teenage childbearing. Data are from Waves 1 – 15 of the female cohort of the National Longitudinal Surveys of Youth 1997 (NLSY97), a nationwide, ongoing cohort study of U.S. men and women born between 1980 and 1984. The analytic sample (N=2,066) was 12-14 years old in 1997 and ethnically diverse (51% white, 27% black, 22% Latina). Using structural equation modeling, we found substance use in early adolescence and perceived peer substance use each partially mediated the relationships among girls' pubertal timing, sexual debut, and teenage childbearing. Our findings suggest early substance use behavior as one modifiable mechanism to be targeted by interventions aimed at preventing teenage childbearing among early developing girls. PMID:26769576

  9. Pubertal development, personality, and substance use: a 10-year longitudinal study from childhood to adolescence.

    Science.gov (United States)

    Castellanos-Ryan, Natalie; Parent, Sophie; Vitaro, Frank; Tremblay, Richard E; Séguin, Jean R

    2013-08-01

    Most research linking early pubertal development to substance use has focused on the effects of pubertal timing (age at which a certain stage of pubertal development is reached or pubertal status at a particular age--related to the maturation disparity hypothesis), but little research has focused on pubertal tempo (rate of growth through pubertal stages--related to the maturation compression hypothesis). However, both timing and tempo have not only been identified as important components of pubertal development, with different predictors, but have also been shown to be independently associated with other adolescent psychopathologies. Using latent growth-curve modeling, this study examined how pubertal status at age 12 and pubertal tempo (between 11 and 13 years) related to substance use from 15 to 16 years in boys from low socioeconomic backgrounds (N = 871). Results showed that both pubertal status at age 12 and tempo were significant predictors of increased levels of substance use and problems in mid to late adolescence. In an attempt to identify mechanisms that may explain the association between pubertal development and substance use it was found that sensation seeking partially mediated the association between pubertal status at age 12 and substance use behaviors. Impulse control was found to moderate the association sensation seeking had with marijuana use frequency, with high sensation-seeking scores predicting higher marijuana use frequency only at low levels of impulse control. These findings highlight the importance of considering multiple sources of individual variability in the pubertal development of boys and provide support for both the maturational disparity and compression hypotheses. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  10. Deleterious effects of obesity on physical fitness in pre-pubertal children.

    Science.gov (United States)

    Ceschia, Arianna; Giacomini, Stefano; Santarossa, Simone; Rugo, Miriam; Salvadego, Desy; Da Ponte, Alessandro; Driussi, Caterina; Mihaleje, Martina; Poser, Stefano; Lazzer, Stefano

    2016-01-01

    The prevalence of obesity in children has increased dramatically during the past decades in Europe and understanding physical fitness and its components in children is critical to design and implement effective interventions. The objective of the present study was to analyse the association between physical fitness (aerobic, speed, agility, power, flexibility and balance) and body mass index (BMI) in pre-pubertal children. A total of 2411 healthy schoolchildren (7-11 years) participated in this study. Anthropometric characteristics and body composition were assessed by skinfold thickness. Physical fitness was measured by nine physical fitness tests: endurance running, 20 m running speed, agility, handgrip strength, standing long jump and squat jump, sit and reach, medicine ball forward throw and static balance. No relevant differences were observed between boys and girls regarding anthropometric characteristics, body composition and physical fitness. However, overweight and obese children showed significantly lower physical fitness levels in endurance running, speed and agility (mean: +18.8, +5.5 and +14.5% of time to complete tasks, respectively), lower limb power normalised to body mass (-23.3%) and balance tests (number of falls: +165.5%) than their normal weight counterparts. On the other hand, obesity did not affect handgrip, throwing and flexibility. In conclusion, increased BMI was associated with lower performance capabilities limiting proper motor skill development, which directly affects the ability of children to take on sports skills. Actions undertaken to promote children's wellness and fitness should be prioritised and introduced early in life with the aim of enhancing physical fitness as well as preventing overweight and obesity.

  11. Mobile phone radiation during pubertal development has no effect on testicular histology in rats.

    Science.gov (United States)

    Tumkaya, Levent; Kalkan, Yildiray; Bas, Orhan; Yilmaz, Adnan

    2016-02-01

    Mobile phones are extensively used throughout the world. There is a growing concern about the possible public health hazards posed by electromagnetic radiation emitted from mobile phones. Potential health risk applies particularly to the most intensive mobile phone users-typically, young people. The aim of this study was to investigate the effects of mobile phone exposure to the testes, by assessing the histopathological and biochemical changes in the testicular germ cells of rats during pubertal development. A total of 12 male Sprague Dawley rats were used. The study group (n = 6) was exposed to a mobile phone for 1 h a day for 45 days, while the control group (n = 6) remained unexposed. The testes were processed with routine paraffin histology and sectioned. They were stained with hematoxylin-eosin, caspase 3, and Ki-67 and then photographed. No changes were observed between the groups (p > 0.05). The interstitial connective tissue and cells of the exposed group were of normal morphology. No abnormalities in the histological appearance of the seminiferous tubules, including the spermatogenic cycle stage, were observed. Our study demonstrated that mobile phones with a low specific absorption rate have no harmful effects on pubertal rat testicles. © The Author(s) 2013.

  12. Adolescents' increasing stress response to social evaluation: pubertal effects on cortisol and alpha-amylase during public speaking.

    Science.gov (United States)

    van den Bos, Esther; de Rooij, Mark; Miers, Anne C; Bokhorst, Caroline L; Westenberg, P Michiel

    2014-01-01

    Stress responses to social evaluation are thought to increase during adolescence, which may be due to pubertal maturation. However, empirical evidence is scarce. This study is the first to investigate the relation between pubertal development and biological responses to a social-evaluative stressor longitudinally. Participants performed the Leiden Public Speaking Task twice, with a 2-year interval (N = 217; age at Time 1: 8-17 years). The results support an increase in sensitivity to social evaluation during adolescence. The overall cortisol and alpha-amylase responses increased-both between and within participants-and were more strongly related to self-reported pubertal development than to age. The cortisol response shifted from speech delivery toward anticipation. The alpha-amylase response increased in both phases. © 2013 The Authors. Child Development © 2013 Society for Research in Child Development, Inc.

  13. Effects of programmed physical activity on body composition in post-pubertal schoolchildren.

    Science.gov (United States)

    Farias, Edson Dos Santos; Gonçalves, Ezequiel Moreira; Morcillo, André Moreno; Guerra-Júnior, Gil; Amancio, Olga Maria Silverio

    2015-01-01

    To assess body composition modifications in post-pubertal schoolchildren after practice of a physical activity program during one school year. The sample consisted of 386 students aged between 15 and 17 years and divided into two groups: the study group (SG) comprised 195 students and the control group (CG), 191. The SG was submitted to a physical activity program and the CG attended conventional physical education classes. Body composition was assessed using body mass index (BMI), percentage of body fat (%BF), fat mass (FM), and lean mass (LM). A positive effect of the physical activity program on body composition in the SG (pgenders. A reduction in %BF (mean of differences = -5.58%) and waist circumference (-2.33 cm), as well as an increase in LM (+2.05 kg) were observed in the SG for both genders, whereas the opposite was observed in the CG. The practice of programmed physical activity promotes significant reduction of body fat in post-pubertal schoolchildren. Copyright © 2013 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  14. The organizational effects of pubertal testosterone on sexual proficiency in adult male Syrian hamsters.

    Science.gov (United States)

    De Lorme, Kayla C; Sisk, Cheryl L

    2016-10-15

    Social proficiency requires making appropriate behavioral adaptations as a result of social experience. For example, male rodents become sexually proficient with experience as demonstrated by a reduction in ectopic (misdirected) mounts, mount-to-intromission ratio, and latency to ejaculation. We previously found that over a series of timed tests with a receptive female, male hamsters deprived of testosterone specifically during puberty (NoT@P) have overall lower levels of sexual behavior and continue to display high levels of ectopic mounts, compared with males that experienced endogenous testosterone during puberty (T@P). These results suggested that pubertal testosterone programs sexual proficiency in adulthood, but because NoT@P males engaged in less sexual behavior than T@P males in these tests, the amount of sexual experience may have been insufficient to improve sexual proficiency. To more rigorously test the hypothesis that pubertal testosterone is necessary for social proficiency in adulthood, the present study compared the behavior of NoT@P and T@P males in a series of 4 trials with a 48-h interval between each trial. Sexual experience was equated by limiting each trial to 5 intromissions. Sexually-naïve males were either gonadectomized prepubertally (NoT@P) or in adulthood (T@P) and received subcutaneous testosterone capsules four weeks later. Two weeks after testosterone replacement, these groups and a group of adult gonad-intact controls began sexual behavior testing. We found that NoT@P males had more ectopic mounts/min across all four tests compared to gonad-intact and T@P males. Moreover, both gonad-intact and T@P males, but not NoT@P males, showed an increase in the number of mounts and intromissions/min between trials 1 and 3. Unexpectedly, both gonad-intact and T@P, but not NoT@P, males showed a decrease in sexual behaviors during trial 4. Thus, T@P males display multiple behavioral adaptations to sexual experience that are not observed in No

  15. Longitudinal impacts of pubertal timing and weight status on adolescent Internet use: Analysis from a cohort study of Taiwanese youths.

    Directory of Open Access Journals (Sweden)

    Meng-Che Tsai

    Full Text Available To investigate the longitudinal impacts of pubertal timing and weight status on Internet use in adolescents.Three waves of data on a longitudinal cohort of 7th grade students (N = 2430 were retrieved from the Taiwan Youth Project. Univariate and multivariate regression models were applied using crude and adjusted odds ratios (OR with 95% confidence intervals (CI to examine the concomitant impacts of pubertal timing and weight status on adolescent Internet use.The dataset identified 210 (8.7% students using the Internet for more than 20 hours/week, and 81 (3.3% were viewing pornographic material online. Early maturing and thin-weight adolescents were at 35% and 46% increased risks of spending long hours on Internet use, respectively. While early puberty was associated with online pornography viewing among males (adjusted OR 1.84, 95% CI 1.04-3.28, early puberty was contrarily a protective factor against online gaming in females (adjusted OR 0.59, 95% CI 0.36-0.96.Early puberty was found to be positively related to adolescent Internet use. Appropriate health education and guidance regarding Internet use should be provided to those with different developing needs.

  16. Longitudinal impacts of pubertal timing and weight status on adolescent Internet use: Analysis from a cohort study of Taiwanese youths.

    Science.gov (United States)

    Tsai, Meng-Che; Strong, Carol; Chen, Wan-Ting; Lee, Chih-Ting; Lin, Chung-Ying

    2018-01-01

    To investigate the longitudinal impacts of pubertal timing and weight status on Internet use in adolescents. Three waves of data on a longitudinal cohort of 7th grade students (N = 2430) were retrieved from the Taiwan Youth Project. Univariate and multivariate regression models were applied using crude and adjusted odds ratios (OR) with 95% confidence intervals (CI) to examine the concomitant impacts of pubertal timing and weight status on adolescent Internet use. The dataset identified 210 (8.7%) students using the Internet for more than 20 hours/week, and 81 (3.3%) were viewing pornographic material online. Early maturing and thin-weight adolescents were at 35% and 46% increased risks of spending long hours on Internet use, respectively. While early puberty was associated with online pornography viewing among males (adjusted OR 1.84, 95% CI 1.04-3.28), early puberty was contrarily a protective factor against online gaming in females (adjusted OR 0.59, 95% CI 0.36-0.96). Early puberty was found to be positively related to adolescent Internet use. Appropriate health education and guidance regarding Internet use should be provided to those with different developing needs.

  17. Effects on steroid hormones secretion resulting from the acute stimulation of sectioning the superior ovarian nerve to pre-pubertal rats

    Directory of Open Access Journals (Sweden)

    Morales-Ledesma Leticia

    2012-10-01

    Full Text Available Abstract In the adult rat, neural signals arriving to the ovary via the superior ovarian nerve (SON modulate progesterone (P4, testosterone (T and estradiol (E2 secretion. The aims of the present study were to analyze if the SON in the pre-pubertal rat also modulates ovarian hormone secretion and the release of follicle stimulating hormone (FSH and luteinizing (LH hormone. P4, T, E2, FSH and LH serum levels were measured 30 or 60 minutes after sectioning the SON of pre-pubertal female rats. Our results indicate that the effects on hormone levels resulting from unilaterally or bilaterally sectioning the SON depends on the analyzed hormone, and the time lapse between surgery and autopsy, and that the treatment yielded asymmetric results. The results also suggest that in the pre-pubertal rat the neural signals arriving to the ovaries via the SON regulate the enzymes participating in P4, T and E2 synthesis in a non-parallel way, indicating that the mechanisms regulating the synthesis of each hormone are not regulated by the same signals. Also, that the changes in the steroids hormones are not explained exclusively by the modifications in gonadotropins secretion. The observed differences in hormone levels between rats sacrificed 30 and 60 min after surgery reflect the onset of the compensatory systems regulating hormones secretion.

  18. EFFECT OF GnRH AND PHOSPHORUS IN DELAYED PUBERTAL SURTI BUFFALO HEIFERS

    Directory of Open Access Journals (Sweden)

    H.B. Dhamsaniya

    2016-06-01

    Full Text Available The study was conducted on eighteen delayed pubertal Surti buffalo heifers, divided into three equal groups (6 in each to evaluate the efficacy of GnRH alone and in combination of phosphorus. The buffalo heifers in Group-I and Group-II were treated with Buserelin acetate (5 ml, IM. Buffalo heifers in Group-II also received additional injection of Toldimphos sodium (10 ml, IM at 3 day interval for 4 times, while buffalo heifers in Group-III served as control. The percentage of induced estrus was highest (83.33% in each treated groups as compared to control group (50%. The mean estrus induction intervals were significantly (P<0.05 shorter in Group-I (20.20 ± 2.18 days and Group-II (18.80 ± 2.32 days as compared to control group (30.24 ± 0.81 days. The conception rate at induced estrus was highest in Group-II (50% followed by Group-I (33.33%. The plasma progesterone levels being significantly lowest on the day of estrus (less than 0.5 ng/ml as compared to pre-treatment days in all groups. The mean total protein and triglycerides levels were differed significantly between the groups on the day of estrus and being significantly higher in Group-II as compared to Group-I and III on that day. A significantly higher level of cholesterol in both treatment groups as compared to the control group during different intervals and also being higher on the day of estrus as compared to pre-treatment days. The mean plasma glucose levels were differed nonsignificantly between and within the treatment and control groups. It is concluded that estrus can be successfully induced in delayed pubertal heifers with the use of GnRH alone and in combination with phosphorus.

  19. Putative effects of endocrine disrupters on pubertal development in the human

    DEFF Research Database (Denmark)

    Teilmann, Grete; Juul, Anders; Skakkebaek, Niels E

    2002-01-01

    developing countries to industrialized countries often develop precocious puberty. Not only precocious puberty, but also delayed puberty can, theoretically, be associated with exposure to endocrine disrupters. While it is very plausible that endocrine disrupters may disturb pubertal development...

  20. The longitudinal effects of physical activity and dietary calcium on bone mass accrual across stages of pubertal development.

    Science.gov (United States)

    Lappe, Joan M; Watson, Patrice; Gilsanz, Vicente; Hangartner, Thomas; Kalkwarf, Heidi J; Oberfield, Sharon; Shepherd, John; Winer, Karen K; Zemel, Babette

    2015-01-01

    Childhood and adolescence are critical periods of bone mineral content (BMC) accrual that may have long-term consequences for osteoporosis in adulthood. Adequate dietary calcium intake and weight-bearing physical activity are important for maximizing BMC accrual. However, the relative effects of physical activity and dietary calcium on BMC accrual throughout the continuum of pubertal development in childhood remains unclear. The purpose of this study was to determine the effects of self-reported dietary calcium intake and weight-bearing physical activity on bone mass accrual across the five stages of pubertal development in a large, diverse cohort of US children and adolescents. The Bone Mineral Density in Childhood study was a mixed longitudinal study with 7393 observations on 1743 subjects. Annually, we measured BMC by dual-energy X-ray absorptiometry (DXA), physical activity and calcium intake by questionnaire, and pubertal development (Tanner stage) by examination for up to 7 years. Mixed-effects regression models were used to assess physical activity and calcium intake effects on BMC accrual at each Tanner stage. We found that self-reported weight-bearing physical activity contributed to significantly greater BMC accrual in both sexes and racial subgroups (black and nonblack). In nonblack males, the magnitude of the activity effect on total body BMC accrual varied among Tanner stages after adjustment for calcium intake; the greatest difference between high- and low-activity boys was in Tanner stage 3. Calcium intake had a significant effect on bone accrual only in nonblack girls. This effect was not significantly different among Tanner stages. Our findings do not support differential effects of physical activity or calcium intake on bone mass accrual according to maturational stage. The study demonstrated significant longitudinal effects of weight-bearing physical activity on bone mass accrual through all stages of pubertal development. © 2014 American

  1. Two organizational effects of pubertal testosterone in male rats: transient social memory and a shift away from long-term potentiation following a tetanus in hippocampal CA1.

    Science.gov (United States)

    Hebbard, Pamela C; King, Rebecca R; Malsbury, Charles W; Harley, Carolyn W

    2003-08-01

    The organizational role of pubertal androgen receptor (AR) activation in synaptic plasticity in hippocampal CA1 and in social memory was assessed. Earlier data suggest pubertal testosterone reduces adult hippocampal synaptic plasticity. Four groups were created following gonadectomy at the onset of puberty: rats given testosterone; rats given testosterone but with the AR antagonist flutamide, present during puberty; rats given testosterone at the end of puberty; and rats given cholesterol at the end of puberty. A tetanus normally inducing long-term potentiation (LTP) was used to stimulate CA1 in the urethane-anesthetized adults during the dark phase of their cycle. Social memory was assessed prior to electrophysiology. Social memory for a juvenile rat at 120 min was seen only in rats not exposed to AR activation during puberty. Pubertal AR activation may induce the reduced social memory of male rats. Early CA1 LTP occurred following tetanus in rats with no pubertal testosterone. Short-term potentiation occurred in rats exposed to pubertal testosterone. Unexpectedly, rats with pubertal AR activation developed long-term depression (LTD). The same pattern was seen in normal male rats. Lack of LTP during the dark phase is consistent with other data on circadian modulation of CA1 LTP. No correlations were seen among social memory scores and CA1 plasticity measures. These data argue for two organizational effects of pubertal testosterone: (1) CA1 synaptic plasticity shifts away from potentiation toward depression; (2) social memory is reduced. Enduring effects of pubertal androgen on limbic circuits may contribute to reorganized behaviors in the postpubertal period.

  2. Secular Trends on Birth Parameters, Growth, and Pubertal Timing in Girls with Turner Syndrome

    Directory of Open Access Journals (Sweden)

    Joachim Woelfle

    2018-02-01

    Full Text Available BackgroundWhether children with chromosomal disorders of growth and puberty are affected by secular trends (STs as observed in the general population remains unanswered, but this question has relevance for expectations of spontaneous development and treatment responses.ObjectivesThe aim of the study was to evaluate STs in birth parameters, growth, and pubertal development in girls with Turner syndrome (TS.Study designRetrospective analysis of KIGS data (Pfizer International Growth Database. We included all TS patients who entered KIGS between 1987 and 2012 and were born from 1975 to 2004, who were prepubertal and growth treatment naïve at first entry (total number: 7,219. Pretreatment height and ages at the start of treatment were compared across 5-year birth year groups, with subgroup analyses stratified by induced or spontaneous puberty start.ResultsWe observed significant STs across the birth year groups for birth weight [+0.18 SD score (SDS, p < 0.001], pretreatment height at mean age 8 years (+0.73 SDS, p < 0.001, height at the start of growth hormone (GH therapy (+0.38 SDS, p < 0.001 and start of puberty (+0.42 SDS, p < 0.001. Spontaneous puberty onset increased from 15 to 30% (p < 0.001. Mean age at the start of GH treatment decreased from 10.8 to 7.4 years (−3.4 years; p < 0.001, and substantial declines were seen in ages at onset of spontaneous and induced puberty (−2.0 years; p < 0.001 and menarche (−2.1 years; p < 0.001.ConclusionEnvironmental changes leading to increased height and earlier and also more common, spontaneous puberty are applicable in TS as in normal girls. In addition, greater awareness for TS may underlie trends to earlier start of GH therapy and induction of puberty at a more physiological age.

  3. The Effect of Wallow on Growth Performance of Pre-Pubertal Pigs in ...

    African Journals Online (AJOL)

    A study was carried out to determine the influence of wallow on the growth performance of growing pigs. Sixteen (16) pre-pubertal pigs (8 males and 8 females) of large white breed, aged three months were randomly assigned to two treatments. There were eight animals per group designated as treatment A = with wallow ...

  4. Sex Variations in Youth Anxiety Symptoms: Effects of Pubertal Development and Gender Role Orientation

    Science.gov (United States)

    Carter, Rona; Silverman, Wendy K.; Jaccard, James

    2011-01-01

    This study evaluated whether pubertal development and gender role orientation (i.e., masculinity and femininity) can partially explain sex variations in youth anxiety symptoms among clinic-referred anxious youth (N = 175; ages 9-13 years; 74% Hispanic; 48% female). Using youth and parent ratings of youth anxiety symptoms, structural equation…

  5. Transitions in body and behavior: a meta-analytic study on the relationship between pubertal development and adolescent sexual behavior.

    Science.gov (United States)

    Baams, Laura; Dubas, Judith Semon; Overbeek, Geertjan; van Aken, Marcel A G

    2015-06-01

    The present meta-analysis studies the relations of pubertal timing and status with sexual behavior and sexual risk behavior among youth aged 10.5-22.4 years. We included biological sex, age, and ethnicity as potential moderators. Four databases were searched for studies (published between 1980 and 2012) on the relation between pubertal timing or status and sexual behavior. The outcomes were (1) sexual intercourse; (2) combined sexual behavior; and (3) risky sexual behavior. Earlier pubertal timing or more advanced pubertal status was related to earlier and more sexual behavior, and earlier pubertal timing was related to more risky sexual behavior. Further, the links between (1) pubertal status and combined sexual behavior and (2) pubertal timing and sexual intercourse status, combined sexual behavior, and risky sexual behavior were stronger for girls than boys. Most links between pubertal status, timing, and sexual behavior and sexual risk behavior were stronger for younger adolescents. Moderation by ethnicity did not yield consistent results. There was significant variation in results among studies that was not fully explained by differences in biological sex, age, and ethnicity. Future research is needed to identify moderators that explain the variation in effects and to design sexual health interventions for young adolescents. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  6. Elite athletes and pubertal delay.

    Science.gov (United States)

    Kapczuk, Karina

    2017-10-01

    Intensive physical training and participation in competitive sports during childhood and early adolescence may affect athletes' pubertal development. On the other hand, pubertal timing, early or late, may impact on an athlete selection for a particular sport. Genetic predisposition, training load, nutritional status and psychological stress determine athletes' pubertal timing. Athletes that practice esthetic sports, especially gymnasts, are predisposed to a delay in pubertal development. The growing evidence indicates that energy deficiency, not a systemic training per se, plays a crucial role in the pathogenesis of functional hypothalamic hypogonadism in female athletes. Metabolic and psychologic stress activate hypothalamic-pituitary-adrenal axis and suppress hypothalamic-pituitary-ovarian axis. Female athletes who do not begin secondary sexual development by the age of 14 or menstruation by the age of 16 warrant a comprehensive evaluation and a targeted treatment. Somatic growth and sexual maturation of elite female athletes are largely sport-specific since each sport favors a particular somatotype and requires a specific training. Chronic negative energy balance resulting from a systemic physical training and inadequate energy intake may delay pubertal development in elite athletes. Youth athletes, especially those engaged in competitive sports that emphasize prepubertal or lean appearance, are at risk of developing relative energy deficiency in sport associated with disordered eating or eating disorders. Management strategies should address the complex conditions underlying functional hypothalamic hypogonadism.

  7. Pubertal breast development in primary school girls in Sokoto, North ...

    African Journals Online (AJOL)

    Background. There is wide variation in normal pubertal timing among various populations. Objectives. To determine the mean age of pubertal stages of breast development and menarche, and the influence of nutrition and ethnicity on pubertal onset in primary school girls in Sokoto, North-Western Nigeria. Methods.

  8. Effect of Leaked Radiation from Microwave Oven on Bone Marrow of Male Rats in Pre and Post Pubertal Stage

    Directory of Open Access Journals (Sweden)

    G Jelodar

    2011-01-01

    Full Text Available Introduction: Increasing hematological diseases along with increased use of microwaves in different systems proposed possible correlation between them. Age of exposure to wave is also an important factor. This study was conducted to evaluate the effect of radiation leakaged from microwave oven on hemopoitic bone marrow cells at pre and post pubertal. Methods: Fourteen male mature (2 months old and 14 male immature rats(one month old were randomly divided in to four groups (control and test. Test groups were exposed, three times a day each time 30 min for 60 days, to microwaves produced by microwave oven. After sixty days, animals were sacrified and bone marrow samples were collected from femural bones. Percent of variose cells type and their morphology were evaluated in 500 cells of each smear. Results: exposure to microwave did not exert visible morphological alteration. In the immature experimental group significant decrease in percent of basophilic rubricyte, polychromatic rubricyte, meta rubricyte and all the erythroid cell types observed(P<0.05, whereas, meta myelocyte, notrophilic band, total myeloid cell types and prolifrative cells, other cell types and the myeloid/erythroid ratio significantly increased(P<0.05. In the mature group, however, a significant decrease in percent of meta rubricyte and myelocyte cells observed(P<0.05, although prolifrative cells and all other cell types were significantly increasing in this group. Conclusion: In conclusion, the radiation leaked from microwave oven in the experimental conditions had no effect on the morphology of hemopoitic bone marrow cells, though the number of these cells was altered especially in immature group.

  9. Putative effects of endocrine disrupters on pubertal development in the human

    DEFF Research Database (Denmark)

    Teilmann, Grete; Juul, Anders; Skakkebaek, Niels E

    2002-01-01

    -called endocrine disrupters. Precocious puberty has been described in several case reports of accidental exposure to oestrogenic compounds in cosmetic products, food and pharmaceuticals. Local epidemics of premature thelarche have also been suggested to be linked to endocrine disrupters. Children adopted from...... developing countries to industrialized countries often develop precocious puberty. Not only precocious puberty, but also delayed puberty can, theoretically, be associated with exposure to endocrine disrupters. While it is very plausible that endocrine disrupters may disturb pubertal development...

  10. Effect of Aegle marmelos and Murraya koenigii in treatment of delayed pubertal buffaloes heifers

    Directory of Open Access Journals (Sweden)

    Mohan M. Baitule

    2016-12-01

    . koenigii alone, were found effective in fertility improvement in delayed pubertal buffalo heifers by increasing ovulation and conception rate.

  11. Depressive symptoms among Hong Kong adolescents: relation to atypical sexual feelings and behaviors, gender dissatisfaction, pubertal timing, and family and peer relationships.

    Science.gov (United States)

    Lam, T H; Stewart, Sunita M; Leung, Gabriel M; Lee, Peter W H; Wong, Joy P S; Ho, L M; Youth Sexuality Task Force

    2004-10-01

    A representative community sample of Hong Kong boys (n = 1,024) and girls (n = 1,403), age 14-18 years, provided information regarding same-sex attraction, gender dissatisfaction, pubertal timing, early experience with sexual intercourse, and depressive symptoms. They also rated the quality of their family and peer relationships and self-perceived attractiveness. Depressive symptoms were higher in youths reporting same-sex attraction, gender dissatisfaction, early pubertal maturation, and early sexual intercourse. Family relationships were less satisfactory for those who reported same-sex attraction, gender dissatisfaction, and early sexual intercourse, and peer relationships were also worse for those who reported gender dissatisfaction. In multivariate analyses, same-sex attraction, early sexual intercourse, and early pubertal maturation were unique and direct contributors to depressive symptoms; however, gender dissatisfaction's association with depressive symptoms was largely accounted for by shared correlations with negative family and peer relationships. The multivariate model explained 11% of the variance of depressive symptoms. These findings offer a preliminary documentation of the prevalence and correlates of atypical sexual self-assessments and behavior among adolescents in Hong Kong. Such information is important if theories of sexual identity and risk factors for depressive symptoms are to have cross-cultural utility. Copyright 2004 Springer Science + Business Media, Inc.

  12. Pubertal development in Danish children

    DEFF Research Database (Denmark)

    Juul, A; Teilmann, G; Scheike, Thomas Harder

    2006-01-01

    .0012). In Danish boys we found that age at genital stage 2 (G2) was 11.83 years. Both sexes were significantly taller compared with data from 1964, but timing of pubertal maturation seemed unaltered. Finally, puberty occurred much later in Denmark compared with recent data from USA. We could not detect any...

  13. Effects of rumen-undegradable protein on intake, performance, and mammary gland development in prepubertal and pubertal dairy heifers.

    Science.gov (United States)

    Silva, A L; Detmann, E; Dijkstra, J; Pedroso, A M; Silva, L H P; Machado, A F; Sousa, F C; Dos Santos, G B; Marcondes, M I

    2018-04-04

    The objective of this study was to evaluate the influence of different amounts of rumen-undegradable protein (RUP) on intake, N balance, performance, mammary gland development, carcass traits, and hormonal status of Holstein heifers at different physiological stages (PS). Sixteen prepubertal (PRE) heifers (initial BW = 106 ± 7.6 kg; age = 4.3 ± 0.46 mo) and 16 pubertal (PUB) heifers (initial BW = 224 ± 7.9 kg; age = 12.6 ± 0.45 mo) were used in an experiment over a period of 84 d. Four diets with increasing RUP contents (38, 44, 51, and 57% of dietary crude protein) and heifers at 2 PS (PRE or PUB) were used in a 4 × 2 factorial arrangement of treatments in a completely randomized design. Throughout the experiment, 2 digestibility trials were performed over 5 consecutive days (starting at d 36 and 78) involving feed and ort sampling and spot collections of feces and urine. At d 0 and 83, body ultrasound images were obtained for real-time carcass trait evaluation. The mammary gland was ultrasonically scanned at d 0 and every 3 wk during the experiment. Blood samples were taken at d 0 and 84 to determine serum concentrations of progesterone, estrogen, insulin-like growth factor I (IGF-I), and insulin. No interaction between PS and the level of RUP was found for any trait. Apparent digestibility of dry matter, organic matter, and neutral detergent fiber corrected for ash and protein was not affected by RUP level but was lower for PRE compared with PUB heifers. Sorting against neutral detergent fiber corrected for ash and protein (tendency only) and for crude protein was greater for PUB than PRE heifers. Pubertal heifers had greater average daily gain (905 vs. 505 g/d) and N retention (25.9 vs. 12.5 g/d) than PRE heifers. In addition, average daily gain and N retention were greatest at 51% RUP of dietary protein. Mammary ultrasonography indicated no effects of RUP amounts on mammary gland composition, whereas PRE heifers had greater pixel values than PUB

  14. Adolescents' Increasing Stress Response to Social Evaluation: Pubertal Effects on Cortisol and Alpha-Amylase during Public Speaking

    Science.gov (United States)

    van den Bos, Esther; de Rooij, Mark; Miers, Anne C.; Bokhorst, Caroline L.; Westenberg, P. Michiel

    2014-01-01

    Stress responses to social evaluation are thought to increase during adolescence, which may be due to pubertal maturation. However, empirical evidence is scarce. This study is the first to investigate the relation between pubertal development and biological responses to a social-evaluative stressor longitudinally. Participants performed the Leiden…

  15. THE EFFECT OF ATRAZINE ON PUBERTY IN THE MALE WISTAR RATS: AN EVALUATION IN THE PROTOCOL FOR THE ASSESSMENT OF PUBERTAL DEVELOPMENT AND THYROID FUNCTION

    Science.gov (United States)

    Since atrazine (ATR), a chlorotriazine herbicide, has been shown previously to alter the secretion of luteinizing hormone (LH) and prolactin (PRL) through a direct effect on the central nervous system (CNS), we hypothesized that exposure to ATR in the EDSTAC male pubertal protoco...

  16. Cumulative and antagonistic effects of a mixture of the antiandrogens vinclozolin and iprodione in the pubertal male rat.

    Science.gov (United States)

    Blystone, Chad R; Lambright, Christy S; Cardon, Mary C; Furr, Johnathan; Rider, Cynthia V; Hartig, Phillip C; Wilson, Vickie S; Gray, Leon E

    2009-09-01

    Vinclozolin and iprodione are dicarboximide fungicides that display antiandrogenic effects in the male rat, which suggests that a mixture would lead to cumulative effects on androgen-sensitive end points. Iprodione is a steroid synthesis inhibitor, but androgen receptor antagonist activity, which is displayed by vinclozolin, has not been fully evaluated. Here, we demonstrate that iprodione binds to the human androgen receptor (IC(50) = 86.0 microM), reduces androgen-dependent gene expression, and reduces androgen-sensitive tissue weights in castrated male rats (Hershberger assay). Since vinclozolin and iprodione affect common targets in the pubertal male rat, we tested the hypothesis that a mixture would have cumulative antiandrogenic effects. An iprodione dose, that does not significantly affect androgen-dependent morphological end points, was combined with vinclozolin doses (2 x 5 factorial design). Sprague-Dawley rats were dosed by gavage with vinclozolin at 0, 10, 30, 60, and 100 mg/kg/day with and without 50 mg iprodione/kg/day from postnatal day (PND) 23 to 55-57 (n = 8 per group). The age at puberty (preputial separation [PPS]), organ weights, serum hormones, and ex vivo testis steroid hormone production were measured. Vinclozolin delayed PPS, reduced androgen-sensitive organ weights, and increased serum testosterone. The addition of iprodione enhanced the vinclozolin inhibition of PPS (PND 47.5 vs.49.1; two-way ANOVA: iprodione main effect p = 0.0002). The dose response for several reproductive and nonreproductive organ weights was affected in a cumulative manner. In contrast, iprodione antagonized the vinclozolin-induced increase in serum testosterone. These results demonstrate that these fungicides interact on common targets in a tissue-specific manner when coadministered to the pubertal male rat.

  17. Comparison of lumbar force between pubertal and post-pubertal adolescents: interference of physical growth, body fat and lifestyle.

    Directory of Open Access Journals (Sweden)

    Mikael Seabra Moraes

    2018-01-01

    Full Text Available Abstract Aim: To compare performance in the lumbar force test in pubertal and post-pubertal adolescents by controlling the interference of physical growth, body fat, screen time and physical activity. Methods: A cross-sectional study with 933 adolescents (492 girls aged 14-19 from the city of São José, Brazil. Lumbar strength was assessed using the isometric lumbar extension test proposed by the Canadian Society of Exercise Physiology. Sexual maturation was classified according to Tanner’s criteria. Physical growth variables (age, body weight, stature, BMI, body fat (triceps and subscapular skinfolds, sedentary behavior based on screen time and overall physical activity were controlled in the Analysis of Covariance (ANCOVA, with a significance level of 5%. Results: Post-pubertal boys presented higher lumbar force compared to pubertal ones only when interference of BMI, body fat, screen time and physical activity was controlled. Pubertal girls presented higher lumbar force compared to post-pubertal ones, both when controlling the analysis for the studied variables and when not controlled by them. Conclusion: BMI, body fat, screen time and physical activity interfere in the difference in lumbar strength of boys, in which post-pubertal boys presented better performance in lumbar force compared to pubertal ones. Regardless of interference or not of these variables, pubertal girls presented better performance in lumbar force when compared to post-pubertal ones.

  18. Puberty and Pubertal Growth in GH-treated SGA Children: Effects of 2 Years of GnRHa Versus No GnRHa.

    Science.gov (United States)

    van der Steen, Manouk; Lem, Annemieke J; van der Kaay, Danielle C M; Hokken-Koèelega, Anita C S

    2016-05-01

    Most studies on puberty in children born small for gestational age (SGA) report height and age at onset of puberty. GH-treated SGA children with an adult height (AH) expectation below -2.5 SDS at onset of puberty can benefit from an additional 2 years of GnRH analog (GnRHa) treatment. There are no data on puberty and growth after discontinuation of GnRHa treatment in GH-treated SGA children. This study aimed to investigate the effects on puberty and pubertal growth of 2 years GnRHa vs no GnRHa in GH-treated SGA children. This was a GH trial involving 76 prepubertal short SGA children (36 girls) treated with GH. Thirty-two children received additional GnRHa for 2 years. Pubertal stages were 3-monthly assessed according to Tanner. Age, bone age, and median height at pubertal onset were lower in girls and boys in the GH/GnRHa group compared with the GH group. In girls and boys treated with GH/GnRHa, pubertal duration after stop of GnRHa treatment was shorter than pubertal duration in those with GH only (40.9 vs 46.7 mo; P = .044; 50.8 vs 57.5 months; P = .006; respectively). Height gain from onset of puberty until AH, including height gain during 2 years of GnRHa treatment, was 25.4 cm in girls and 33.0 cm in boys, which was 6.6 cm more than girls and boys treated with GH only. AH was similar in children treated with GH/GnRHa compared with those with GH only. GH-treated SGA children who start puberty with an AH expectation below -2.5 SDS and are treated with 2 years of GnRHa have a shorter pubertal duration after discontinuation of GnRHa compared with pubertal duration in children treated with GH only. Height gain from onset of puberty until AH is, however, more due to adequate growth during 2 years of GnRHa treatment resulting in a similar AH as children treated with GH only.

  19. Nutrition and pubertal development

    OpenAIRE

    Soliman, Ashraf; De Sanctis, Vincenzo; Elalaily, Rania

    2014-01-01

    Nutrition is one of the most important factors affecting pubertal development. Puberty entails a progressive nonlinear process starting from prepubescent to full sexual maturity through the interaction and cooperation of biological, physical, and psychological changes. Consuming an adequate and balanced healthy diet during all phases of growth (infancy, childhood and puberty) appears necessary both for proper growth and normal pubertal development. Girls begin puberty at an earlier age compar...

  20. Longitudinal change in the neural bases of adolescent social self-evaluations: effects of age and pubertal development.

    Science.gov (United States)

    Pfeifer, Jennifer H; Kahn, Lauren E; Merchant, Junaid S; Peake, Shannon J; Veroude, Kim; Masten, Carrie L; Lieberman, Matthew D; Mazziotta, John C; Dapretto, Mirella

    2013-04-24

    Self-evaluations undergo significant transformation during early adolescence, developing in parallel with the heightened complexity of teenagers' social worlds. Intuitive theories of adolescent development, based in part on animal work, suggest that puberty is associated with neural-level changes that facilitate a "social reorientation" (Nelson et al., 2005). However, direct tests of this hypothesis using neuroimaging are limited in humans. This longitudinal fMRI study examined neurodevelopmental trajectories associated with puberty, self-evaluations, and the presumed social reorientation during the transition from childhood to adolescence. Participants (N = 27, mean age = 10.1 and 13.1 years at time points one and two, respectively) engaged in trait evaluations of two targets (the self and a familiar fictional other), across two domains of competence (social and academic). Responses in ventromedial PFC increased with both age and pubertal development during self-evaluations in the social domain, but not in the academic domain. These results suggest that changes in social self-evaluations are intimately connected with biology, not just peer contexts, and provide important empirical support for the relationship between neurodevelopment, puberty, and social functioning.

  1. Gender specific effect of major dietary patterns on the metabolic syndrome risk in Korean pre-pubertal children

    OpenAIRE

    Park, Soo Jin; Lee, Seung Min; Kim, Seon Mee; Lee, Myoungsook

    2013-01-01

    There is a lack of data on metabolic risk factors during pre-puberty, which is important for identifying the subgroups of youth, at whom early interventions should be targeted. In this study, we evaluated the prevalence of metabolic risk factors and its subsequent relations with dietary patterns in Korean pre-pubertal children through a cross-sectional sample (n = 1,008; boys = 513) of pre-pubertal children (aged 8-9 years) from a sub-study of the Korea Metabolic Syndrome Research Initiatives...

  2. Effects of Habitual Physical Activity and Fitness on Tibial Cortical Bone Mass, Structure and Mass Distribution in Pre-pubertal Boys and Girls: The Look Study.

    Science.gov (United States)

    Duckham, Rachel L; Rantalainen, Timo; Ducher, Gaele; Hill, Briony; Telford, Richard D; Telford, Rohan M; Daly, Robin M

    2016-07-01

    Targeted weight-bearing activities during the pre-pubertal years can improve cortical bone mass, structure and distribution, but less is known about the influence of habitual physical activity (PA) and fitness. This study examined the effects of contrasting habitual PA and fitness levels on cortical bone density, geometry and mass distribution in pre-pubertal children. Boys (n = 241) and girls (n = 245) aged 7-9 years had a pQCT scan to measure tibial mid-shaft total, cortical and medullary area, cortical thickness, density, polar strength strain index (SSIpolar) and the mass/density distribution through the bone cortex (radial distribution divided into endo-, mid- and pericortical regions) and around the centre of mass (polar distribution). Four contrasting PA and fitness groups (inactive-unfit, inactive-fit, active-unfit, active-fit) were generated based on daily step counts (pedometer, 7-days) and fitness levels (20-m shuttle test and vertical jump) for boys and girls separately. Active-fit boys had 7.3-7.7 % greater cortical area and thickness compared to inactive-unfit boys (P girls, but active-fit girls had 6.1 % (P girls, which was likely due to their 6.7 % (P active-fit girls. Higher levels of habitual PA-fitness were associated with small regional-specific gains in 66 % tibial cortical bone mass in pre-pubertal children, particularly boys.

  3. Nutrition and pubertal development

    Directory of Open Access Journals (Sweden)

    Ashraf Soliman

    2014-01-01

    Full Text Available Nutrition is one of the most important factors affecting pubertal development. Puberty entails a progressive nonlinear process starting from prepubescent to full sexual maturity through the interaction and cooperation of biological, physical, and psychological changes. Consuming an adequate and balanced healthy diet during all phases of growth (infancy, childhood and puberty appears necessary both for proper growth and normal pubertal development. Girls begin puberty at an earlier age compared to past decades. Excessive eating of many processed, high-fat foods, may be the cause of this phenomenon. Overweight or obese children are more likely to enter puberty early. Some evidence suggests that obesity can accelerate the onset of puberty in girls and may delay the onset of puberty in boys. Moreover, the progression of puberty is affected by nutrition. On the other hand, puberty triggers a growth spurt, which increases nutritional needs including macro and micronutrients. Increased caloric, protein, iron, calcium, zinc and folate needs have to be provided during this critical period of rapid growth. Severe primary or secondary malnutrition also can delay the onset and progression of puberty. The higher incidence of anorexia nervosa and bulimia in adolescents imposes a nutritional risk on pubertal development. Moreover, many environmental endocrine disruptors (EDs have been identified that can significantly impair the normal course of puberty. This mini-review sums up some important findings in this important complex that link nutrition and pubertal development.

  4. Interactive effects of ethanol on ulcerative colitis and its associated testicular dysfunction in pubertal BALB/c mice.

    Science.gov (United States)

    Adedara, Isaac A; Ajayi, Babajide O; Awogbindin, Ifeoluwa O; Farombi, Ebenezer O

    2017-11-01

    Available epidemiological reports have indicated an increase in the incidence of ulcerative colitis, as well as alcohol consumption, globally. The present study investigated the possible interactive effects of ethanol consumption on ulcerative colitis and its associated testicular dysfunction using six groups of 12 pubertal mice each. Group I (Control) mice received drinking water alone. Group II mice received ethanol alone at 5 g/kg body weight. Group III mice received 2.5% dextran sulphate sodium (DSS) in drinking water followed by normal drinking water. Groups IV, V, and VI mice received DSS followed by ethanol at 1.25, 2.5, and 5 g/kg, respectively. Administration of ethanol to mice with ulcerative colitis intensified the disease-activity index with marked reduction in colon length, colon mass index, body weight gain, and organo-somatic indices of testes and epididymis when compared with the DSS-alone group. Moreover, ethanol exacerbated colitis-mediated decrease in enzymatic and non-enzymatic antioxidants but increased the oxidative stress and inflammatory biomarkers in the testes and epididymis. The diminution in luteinizing hormone, follicle stimulating hormone, and testosterone levels was intensified following administration of ethanol to mice with ulcerative colitis that were administered 5 g/kg ethanol alone. The decrease in sperm functional parameters and testicular spermatogenic indices as well as histopathological damage in colon, testes, and epididymis was aggravated following administration of ethanol to mice with ulcerative colitis. In conclusion, the exacerbating effects of ethanol on ulcerative colitis-induced testicular dysfunction are related to increased oxidative stress and inflammation in the treated mice. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Effect of A 16 Week Combined Strength and Plyometric Training Program Followed by A Detraining Period on Athletic Performance in Pubertal Volleyball Players.

    Science.gov (United States)

    Fathi, Abed; Hammami, Raouf; Moran, Jason; Borji, Rihab; Sahli, Sonia; Rebai, Haithem

    2018-02-01

    The purpose of this study was to determine the effects of 16 weeks of combined strength and plyometric training or plyometric training alone, and how a detraining program can modify adaptations in response to the training stimulus. Sixty male volleyball players (circa PHV:-1 to +1 years from PHV) were assigned to a Combined Training group (CTG) (n=20), a Plyometric Training group (PTG) (n=20) or a control group (CG) (n=20). The experimental groups (CTG and PTG) participated in training twice weekly for 16 weeks. Thigh muscle volume, body fat, flexibility, sprint, jump height and medicine ball throw were measured at pre-training, post-training and detraining. Respectively, the CTG and PTG showed increases in thigh muscle volume (Effect size: 0.71 and 0.42), and decreases in body fat (-0.42 and -0.34) as well as improvements in 5 m sprint (-0.69 and -0.46) 10 m sprint (-0.31 and -0.3), lower body muscle power (0.44 and 0.36) and upper body muscle power (1.32 and 0.7). After the detraining period, all groups maintained previously attained muscle power (6.79% to 9.87%; pplyometric training provided better improvements than plyometric training only. The combination of strength and plyometric training is a time-effective training modality that confers improvements in physical performance measures, muscle size and body fat. A temporary period of detraining may not undermine performance gains in pubertal volleyball players.

  6. Contributions of Function-Altering Variants in Genes Implicated in Pubertal Timing and Body Mass for Self-Limited Delayed Puberty.

    Science.gov (United States)

    Howard, Sasha R; Guasti, Leonardo; Poliandri, Ariel; David, Alessia; Cabrera, Claudia P; Barnes, Michael R; Wehkalampi, Karoliina; O'Rahilly, Stephen; Aiken, Catherine E; Coll, Anthony P; Ma, Marcella; Rimmington, Debra; Yeo, Giles S H; Dunkel, Leo

    2018-02-01

    Self-limited delayed puberty (DP) is often associated with a delay in physical maturation, but although highly heritable the causal genetic factors remain elusive. Genome-wide association studies of the timing of puberty have identified multiple loci for age at menarche in females and voice break in males, particularly in pathways controlling energy balance. We sought to assess the contribution of rare variants in such genes to the phenotype of familial DP. We performed whole-exome sequencing in 67 pedigrees (125 individuals with DP and 35 unaffected controls) from our unique cohort of familial self-limited DP. Using a whole-exome sequencing filtering pipeline one candidate gene [fat mass and obesity-associated gene (FTO)] was identified. In silico, in vitro, and mouse model studies were performed to investigate the pathogenicity of FTO variants and timing of puberty in FTO+/- mice. We identified potentially pathogenic, rare variants in genes in linkage disequilibrium with genome-wide association studies of age at menarche loci in 283 genes. Of these, five genes were implicated in the control of body mass. After filtering for segregation with trait, one candidate, FTO, was retained. Two FTO variants, found in 14 affected individuals from three families, were also associated with leanness in these patients with DP. One variant (p.Leu44Val) demonstrated altered demethylation activity of the mutant protein in vitro. Fto+/- mice displayed a significantly delayed timing of pubertal onset (P puberty in the general population may contribute to the pathogenesis of self-limited DP. Copyright © 2017 Endocrine Society

  7. Pubertal development in ICSI children

    NARCIS (Netherlands)

    Belva, F.; Roelants, M.; Painter, R.; Bonduelle, M.; Devroey, P.; de Schepper, J.

    2012-01-01

    To date, information on the pubertal development of adolescents born after ICSI is scarce, since the very first cohort is only now reaching young adulthood. In this study, pubertal development at the age of 14 was characterized in a longitudinally followed cohort of ICSI-conceived teenagers and

  8. Peer Exclusion During the Pubertal Transition: The Role of Social Competence.

    Science.gov (United States)

    Carter, Rona; Halawah, Amira; Trinh, Sarah L

    2018-01-01

    For some youth, early puberty is accompanied by peer exclusion. Yet early developers may experience less peer exclusion if they have social competence, which would bolster their ability to develop and maintain positive relationships with their peers. Accordingly, the present study tests whether pubertal timing and tempo predicts decrements in children's social competence and whether decrements in social competence account for associations between puberty (timing and tempo) and peer exclusion over time. Longitudinal data were drawn from 1364 families (48% female; 76% White; M = 9.32 years, SD = .48, at Wave 3) who participated in Waves 3-5 (i.e., grades 4-6) of Phase III of the NICHD-SECCYD. The results from latent growth curve models indicated that earlier pubertal timing and more rapid pubertal tempo among girls were associated with high initial levels of peer exclusion. Moreover, mediation analyses revealed that early developers' susceptibility to peer exclusion was associated with their initial level of social competence. In boys, pubertal timing and tempo were not directly associated with peer exclusion; instead, indirect effects of pubertal timing on peer exclusion (intercept, slope) occurred through initial levels of social competence. On average, early developers' who had low levels of social competence also had high initial levels of peer exclusion but experienced decrements in peer exclusion over time. The association between the intercepts for puberty and peer exclusion and the slopes for social competence and peer exclusion were stronger for boys than girls. Overall, our findings suggest that early developers' susceptibility to and experiences of peer exclusion are associated with their development of social competence.

  9. Pubertal changes in emotional information processing: pupillary, behavioral, and subjective evidence during emotional word identification.

    Science.gov (United States)

    Silk, Jennifer S; Siegle, Greg J; Whalen, Diana J; Ostapenko, Laura J; Ladouceur, Cecile D; Dahl, Ronald E

    2009-01-01

    This study investigated pupillary and behavioral responses to an emotional word valence identification paradigm among 32 pre-/early pubertal and 34 mid-/late pubertal typically developing children and adolescents. Participants were asked to identify the valence of positive, negative, and neutral words while pupil dilation was assessed using an eyetracker. Mid-/late pubertal children showed greater peak pupillary reactivity to words presented during the emotional word identification task than pre-/early pubertal children, regardless of word valence. Mid-/late pubertal children also showed smaller sustained pupil dilation than pre-/early pubertal children after the word was no longer on screen. These findings were replicated controlling for participants' age. In addition, mid-/late pubertal children had faster reaction times to all words, and rated themselves as more emotional during their laboratory visit compared to pre-/early pubertal children. Greater recall of emotional words following the task was associated with mid-/late pubertal status, and greater recall of emotional words was also associated with higher peak pupil dilation. These results provide physiological, behavioral, and subjective evidence consistent with a model of puberty-specific changes in neurobehavioral systems underpinning emotional reactivity.

  10. Pubertal development in Danish children

    DEFF Research Database (Denmark)

    Juul, A; Teilmann, G; Scheike, Thomas Harder

    2006-01-01

    differences between USA and Denmark, as well as to look for possible secular trends in pubertal development. Healthy Caucasian children from public schools in Denmark participated in the study which was carried out in 1991-1993. A total number of 826 boys and 1,100 girls (aged 6.0-19.9 years) were included......, and pubertal stages were assessed by clinical examination according to methods of Tanner. In boys testicular volume was determined using an orchidometer. We found that age at breast development 2 (B2) was 10.88 years, and mean menarcheal age was 13.42 years. Girls with body mass index (BMI) above the median...... genetic polymorphisms, nutrition, physical activity or endocrine disrupting chemicals must therefore also be considered. Therefore, we believe it is crucial to monitor the pubertal development closely in Denmark in the coming decades....

  11. The duration of pubertal growth peak among three skeletal classes

    Directory of Open Access Journals (Sweden)

    Waqar Jeelani

    Full Text Available ABSTRACT Introduction: Pubertal growth peak is closely associated with a rapid increase in mandibular length and offers a wide range of therapeutic modifiability. Objective: The aim of the present study was to determine and compare the mean ages of onset and duration of pubertal growth peak among three skeletal classes. Methods: A retrospective cross-sectional study was conducted using lateral cephalograms of 230 subjects with growth potential (110 males, 120 females. Subjects were categorized into three classes (Class I = 81, Class II = 82, Class III = 67, according to the sagittal relationship established between the maxilla and the mandible. The cervical vertebral maturation stage was recorded by means of Baccetti's method. The mean ages at CS3 and CS4 and the CS3-CS4 age interval were compared between boys and girls and among three skeletal classes. Results: Pubertal growth peak occurred on average four months earlier in girls than boys (p = 0.050. The average duration of pubertal growth peak was 11 months in Class I, seven months in Class II and 17 months in Class III subjects. Interclass differences were highly significant (Cohen's d > 0.08. However, no significant difference was found in the timing of pubertal growth peak onset among three skeletal classes (p = 0.126 in boys, p = 0.262 in girls. Conclusions: Girls enter pubertal growth peak on average four months earlier than boys. Moreover, the duration of pubertal growth peak is on average four months shorter in Class II and six months longer in Class III subjects as compared to Class I subjects.

  12. The Examination of the Effectiveness of an Educational Intervention based on the Planned Behavior Theory on Improving Pubertal Health Behavior in Female High School Students

    Directory of Open Access Journals (Sweden)

    Farnaz Eslamimehr

    2017-09-01

    Full Text Available Background: Puberty is a period of psychological, physical, mental, emotional and social growth that stability and development of personality occurs in this period. This study aimed to determine the effect of planned behavior theory on improving pubertal health behavior in female first grade high school students. Materials and Methods:  A quasi-experimental intervention was conducted in female high school in Khamir city, Iran in 2015. One of the schools were randomly assigned to the control group and other to the experimental group. Using the formula sample, 60 students were selected from each school. Samples were evaluated in two stages through pre-test and two months later via post-test by administered questionnaire including questions about demographic characteristics and structures of planned behavior theory. The content of training was presented through lecture group discussion with teaching aids such as booklet and pamphlet. The collected data were analyzed using SPSS version 22. Results: The intervention group mean age at first menstrual period was 12.30 ± 0.84 years old and for control group was 12.25 ± 0.79 years old. The results showed that two months after the intervention, health behaviors, subjective norms, behavioral intention, perceived behavioral control, and attitude, were significantly higher than pre- intervention (P

  13. The Effect of Low Monotonic Doses of Zearalenone on Selected Reproductive Tissues in Pre-Pubertal Female Dogs—A Review

    Directory of Open Access Journals (Sweden)

    Magdalena Gajęcka

    2015-11-01

    Full Text Available The growing interest in toxic substances combined with advancements in biological sciences has shed a new light on the problem of mycotoxins contaminating feeds and foods. An interdisciplinary approach was developed by identifying dose-response relationships in key research concepts, including the low dose theory of estrogen-like compounds, hormesis, NOAEL dose, compensatory response and/or food tolerance, and effects of exposure to undesirable substances. The above considerations increased the researchers’ interest in risk evaluation, namely: (i clinical symptoms associated with long-term, daily exposure to low doses of a toxic compound; and (ii dysfunctions at cellular or tissue level that do not produce clinical symptoms. Research advancements facilitate the extrapolation of results and promote the use of novel tools for evaluating the risk of exposure, for example exposure to zearalenone in pre-pubertal female dogs. The arguments presented in this paper suggest that low doses of zearalenone in commercial feeds stimulate metabolic processes and increase weight gains. Those processes are accompanied by lower proliferation rates in the ovaries, neoangiogenesis and vasodilation in the ovaries and the uterus, changes in the steroid hormone profile, and changes in the activity of hydroxysteroid dehydrogenases. All of the above changes result from exogenous hyperestrogenizm.

  14. Fertility of the Small East African goat following pre-pubertal infection with Trypanosoma congolense

    International Nuclear Information System (INIS)

    O'Hara, H.B.; Gombe, S.

    1991-01-01

    Pre-pubertal male and female Small East African goats were infected with Trypanosoma congolense at 4-5 months of age. Changes in body weight and haemogram were monitored weekly. Progesterone and testosterone measurements were made three times weekly until the goats either reached puberty or 18 months of age. Onset of puberty was determined from observation of oestrus behaviour, mating or increase in libidio; this was confirmed by elevation in plasma progesterone or testosterone levels. Trypanosomiasis affected pre-pubertal goats by reducing body weight gain and delaying onset of puberty. Histological examination of the gonads showed pronounced pathological changes. These effects were reversed by treatment with isometamidium chloride (Samorin, May and Baker). It was concluded that early treatment of infected goats before serious gonadal damage could occur allowed full restoration of reproductive function. (author). 6 refs, 4 figs, 1 tab

  15. Effect of Radiation Leakage of Microwave Oven on Rat Serum Testosterone at Pre and Post Pubertal Stage

    Directory of Open Access Journals (Sweden)

    Y Zare

    2008-01-01

    Full Text Available Introduction: Since discovery of high frequency waves, their biological effects have been in great attention. Increased male fertility problems proposed their possible relation to use of microwaves. Testes are of very active body tissues, which can be affected by these waves. Age of exposure may also be an important factor. Methods: This study was carried out to evaluated testosterone level in rats exposed to microwave radiation at pre and post puberty. For this study 18 adult (2 month old and 18 immature (1 month old male rats were selected and each group divided in two groups, control and test group. Test groups were exposed to 2450 MHZ microwaves produced by microwave oven (LG Brant, three times a day, 30 minute each time. Control groups were kept in laboratory at same temperature and light condition. After 60 days blood was collected by heart puncture and testosterone was measured in serum by RIA method. Mean testosterone levels were compared by T-test. Result: The results showed that in immature group testosterone has not changed significantly compare to control group; however in adult group this value was significantly decreased in test group in comparison with control (P<0.005. Conclusion: exposure to microwaves leakage of microwave oven decreased testosterone in adult male rats, which may be due to its direct effect on Leydig cells or indirectly through its effect on pituitary and hypothalamus.

  16. Maternal pre-pregnancy body mass index and pubertal development among sons

    DEFF Research Database (Denmark)

    Hounsgaard, M L; Håkonsen, L B; Vested, A

    2014-01-01

    Maternal overweight and obesity in pregnancy has been associated with earlier age of menarche in daughters as well as reduced semen quality in sons. We aimed at investigating pubertal development in sons born by mothers with a high body mass index (BMI). The study included 2522 sons of mothers...... indicators of pubertal development, results also indicated earlier pubertal development among sons of obese mothers. After excluding sons of underweight mothers in a subanalysis, we observed an inverse trend between maternal pre-pregnancy BMI and age at regular shaving, acne and first nocturnal emission....... In conclusion, maternal pre-pregnant obesity may be related to earlier timing of pubertal milestones among sons. More research, preferably based on prospectively collected information about pubertal development, is needed to draw firm conclusions....

  17. Pubertal development among girls with classical congenital adrenal hyperplasia initiated on treatment at different ages

    Directory of Open Access Journals (Sweden)

    Bindu Kulshreshtha

    2012-01-01

    Full Text Available Introduction: Children with congenital adrenal hyperplasia (CAH provide us an opportunity to study the clinical effects of androgen excess in humans. We studied the sequence of pubertal development in girls with congenital adrenal hyperplasia initiated on treatment at different ages, to assess the effects of androgen exposure on the Hypothalamic-Pituitary-Ovarian (HPO axis. Materials and Methods: Girls more than 18 years of age, with CAH, on follow-up at this hospital were the subjects for this study. Details of history, physical findings, laboratory evaluation, and medication were noted from their case records and verified from the patients and their / parents, in addition to assessment of their present health status. Result: We studied 24 patients of classical CAH (SW-2, SV-22, average age - 24.5 ± 6.6 years. All had varying degrees of genital ambiguity (Prader stage 3 (n = 13, Prader stage 2 (n = 10, Prader stage 1 (n = 1. Among them were13 girls, who were started on steroids after eight years of age. Girls who received treatment from infancy and early childhood had normal pubertal development (mean age at menarche 11.4 ± 1.7 years. Hirsutism was not a problem among them. Untreated children had progressive clitoral enlargement throughout childhood, developed pubic hair at around three to six years of age, and facial hair between nine and eleven years. Plasma testosterone ranged from 3 to 6 ng / ml prior to treatment. Six of the 13 untreated CAH girls had subtle breast development starting at ages 11 - 16 years and three had spontaneous infrequent vaginal bleeding starting at ages 11 - 17. Steroid supplementation initiated pubertal changes in older girls in two-to-six months′ time. Conclusion: There was a delay in HPO axis maturation (as evidenced by delayed pubertal development in the absence of treatment in girls with CAH. This could be corrected with steroid supplementation.

  18. The physiology and timing of male puberty

    DEFF Research Database (Denmark)

    Tinggaard, Jeanette; Mieritz, Mikkel Grunnet; Sørensen, Kaspar

    2012-01-01

    To describe available markers of male puberty, discuss associations between adiposity and pubertal timing and to review recent evidence of a possible secular trend in male pubertal timing.......To describe available markers of male puberty, discuss associations between adiposity and pubertal timing and to review recent evidence of a possible secular trend in male pubertal timing....

  19. Cummulative and antagonistic effects of a mixture of the antiandrogrens vinclozolin and iprodione in the pubertal male rat:

    Science.gov (United States)

    Vinclozolin and iprodione are dicarboximide fungicides that display anti-androgenic effects in the male rat, which suggests co-exposure to these fungicides would lead to cumulative effects on androgen-sensitive endpoints. Iprodione is a steroid synthesis inhibitor, but AR antagon...

  20. Exciting fear in adolescence: Does pubertal development alter threat processing?

    Directory of Open Access Journals (Sweden)

    Jeffrey M. Spielberg

    2014-04-01

    Full Text Available Adolescent development encompasses an ostensible paradox in threat processing. Risk taking increases dramatically after the onset of puberty, contributing to a 200% increase in mortality. Yet, pubertal maturation is associated with increased reactivity in threat-avoidance systems. In the first part of this paper we propose a heuristic model of adolescent affective development that may help to reconcile aspects of this paradox, which focuses on hypothesized pubertal increases in the capacity to experience (some fear-evoking experiences as an exciting thrill. In the second part of this paper, we test key features of this model by examining brain activation to threat cues in a longitudinal study that disentangled pubertal and age effects. Pubertal increases in testosterone predicted increased activation to threat cues, not only in regions associated with threat avoidance (i.e., amygdala, but also regions associated with reward pursuit (i.e., nucleus accumbens. These findings are consistent with our hypothesis that puberty is associated with a maturational shift toward more complex processing of threat cues—which may contribute to adolescent tendencies to explore and enjoy some types of risky experiences.

  1. Exciting fear in adolescence: does pubertal development alter threat processing?

    Science.gov (United States)

    Spielberg, Jeffrey M; Olino, Thomas M; Forbes, Erika E; Dahl, Ronald E

    2014-04-01

    Adolescent development encompasses an ostensible paradox in threat processing. Risk taking increases dramatically after the onset of puberty, contributing to a 200% increase in mortality. Yet, pubertal maturation is associated with increased reactivity in threat-avoidance systems. In the first part of this paper we propose a heuristic model of adolescent affective development that may help to reconcile aspects of this paradox, which focuses on hypothesized pubertal increases in the capacity to experience (some) fear-evoking experiences as an exciting thrill. In the second part of this paper, we test key features of this model by examining brain activation to threat cues in a longitudinal study that disentangled pubertal and age effects. Pubertal increases in testosterone predicted increased activation to threat cues, not only in regions associated with threat avoidance (i.e., amygdala), but also regions associated with reward pursuit (i.e., nucleus accumbens). These findings are consistent with our hypothesis that puberty is associated with a maturational shift toward more complex processing of threat cues--which may contribute to adolescent tendencies to explore and enjoy some types of risky experiences. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Sperm abnormalities induced by pre-pubertal exposure to cyclophosphamide are effectively mitigated by Moringa oleifera leaf extract.

    Science.gov (United States)

    Nayak, G; Vadinkar, A; Nair, S; Kalthur, S G; D'Souza, A S; Shetty, P K; Mutalik, S; Shetty, M M; Kalthur, G; Adiga, S K

    2016-03-01

    Moringa oleifera L. is a medicinal plant with potential antioxidant property. This study was aimed at investigating the chemoprotective effect of Moringa oleifera leaf extract (MOE) on cyclophosphamide (CP)-induced testicular toxicity. Two-week-old male Swiss albino mice were intraperitoneally injected with phosphate-buffered saline, 50 mg kg(-1) of CP and 25 mg kg(-1) of MOE. In combination treatment, mice were injected with 25 mg kg(-1) of MOE 24 h prior to CP injection, 24 h prior and post-CP injection and 24 h post-CP injection for 5 consecutive days (10 mg kg(-1) ). Six weeks later, mice were sacrificed to assess epididymal sperm parameters. MOE alone did not have any significant effect on sperm parameters. However, acute injection of CP resulted in significant decline in motility (P < 0.001), increase in head abnormality (P < 0.01) and DNA damage (P < 0.05). Combining MOE with CP increased the sperm density, motility and reduced head defect and DNA damage, irrespective of the schedule and dosage of MOE. Administration of MOE prior to CP significantly elevated the level of superoxide dismutase and catalase with concomitant decrease in lipid peroxidation in the testicular tissue. In conclusion, MOE may have potential benefit in reducing the loss of male gonadal function following chemotherapy. © 2015 Blackwell Verlag GmbH.

  3. Pubertal development in healthy children is mirrored by DNA methylation patterns in peripheral blood

    DEFF Research Database (Denmark)

    Almstrup, Kristian; Johansen, Marie Lindhardt; Busch, Alexander S.

    2016-01-01

    Puberty marks numerous physiological processes which are initiated by central activation of the hypothalamic–pituitary–gonadal axis, followed by development of secondary sexual characteristics. To a large extent, pubertal timing is heritable, but current knowledge of genetic polymorphismsonly...... explains few months in the large inter-individual variation in the timing of puberty. We have analysed longitudinal genome-wide changes in DNA methylation in peripheral blood samples (n = 102) obtained from 51 healthy children before and after pubertal onset. We show that changes in single methylation...... sites are tightly associated with physiological pubertal transition and altered reproductive hormone levels. These methylation sites cluster in and around genes enriched for biological functions related to pubertal development. Importantly, we identified that methylation of the genomic region containing...

  4. Urinary phthalate excretion in 555 healthy Danish boys with and without pubertal gynaecomastia

    DEFF Research Database (Denmark)

    Mieritz, Mikkel G; Frederiksen, Hanne; Sørensen, Kaspar

    2012-01-01

    Pubertal gynaecomastia is a clinical sign of an oestrogen-androgen imbalance, which occurs in 40-60% of adolescent Caucasian boys. In most cases no underlying endocrinopathy can be identified. A recent study reports higher plasma phthalate levels in Turkish boys with pubertal gynaecomastia....... Therefore, we asked whether there was an association between concurrent measures of urinary phthalate metabolites and pubertal timing as well as the presence of gynaecomastia in otherwise healthy boys. We studied a total of 555 healthy boys (age 6.07-19.83 years) as part of the COPENHAGEN Puberty Study....... Anthropometry and pubertal stages (PH1-6 and G1-5) were evaluated, and the presence of gynaecomastia was assessed. Non-fasting blood samples were analysed for serum testosterone and morning urine samples were analysed for the total content of 12 phthalate metabolites (MEP, MnBP, MiBP, MBzP, MEHP, MEHHP, MEOHP...

  5. The mammary gland is a sensitive pubertal target in CD-1 and C57Bl/6 mice following perinatal perfluorooctanoic acid (PFOA) exposure.

    Science.gov (United States)

    Tucker, Deirdre K; Macon, Madisa B; Strynar, Mark J; Dagnino, Sonia; Andersen, Erik; Fenton, Suzanne E

    2015-07-01

    Perfluorooctanoic acid (PFOA) is a developmental toxicant in mice, with varied strain outcomes depending on dose and period of exposure. The impact of PFOA on female mouse pubertal development at low doses (≤1mg/kg) has yet to be determined. Therefore, female offspring from CD-1 and C57Bl/6 dams exposed to PFOA, creating serum concentrations similar to humans, were examined for pubertal onset, including mammary gland development. Pups demonstrated a shorter PFOA elimination half-life than that reported for adult mice. Prenatal exposure to PFOA caused significant mammary developmental delays in female offspring in both strains. Delays started during puberty and persisted into young adulthood; severity was dose-dependent. Also an evaluation of female serum hormone levels and pubertal timing onset revealed no effects of PFOA compared to controls in either strain. These data suggest that the mammary gland is more sensitive to early low level PFOA exposures compared to other pubertal endpoints, regardless of strain. Published by Elsevier Inc.

  6. Induction of a hypothyroid state during juvenile development delays pubertal reactivation of the neuroendocrine system governing luteinising hormone secretion in the male rhesus monkey (Macaca mulatta).

    Science.gov (United States)

    Mann, D R; Bhat, G K; Stah, C D; Pohl, C R; Plant, T M

    2006-09-01

    The present study aimed to determine the influence of thyroid status on the timing of the pubertal resurgence in gonadotrophin-releasing hormone pulse generator activity [tracked by circulating luteinising hormone (LH) levels] in male rhesus monkeys. Six juvenile monkeys were orchidectomised and then treated with the antithyroid drug, methimazole, from 15-19 months until 36 months of age, at which time thyroxine (T(4)) replacement was initiated. Four additional agonadal monkeys served as controls. Blood samples were drawn weekly for hormonal assessments. Body weight, crown-rump length and bone age were monitored at regular intervals. By 8 weeks of methimazole treatment, plasma T(4) had fallen sharply, and the decline was associated with a plasma thyroid-stimulating hormone increase. In controls, plasma LH levels remained undetectable until the pubertal rise occurred at 29.3 +/- 0.2 months of age. This developmental event occurred in only half of the methimazole-treated animals before 36 months of age when T(4) replacement was initiated. The hypothyroid state was associated with a profound arrest of growth and bone maturation, but increased body mass indices and plasma leptin levels. T(4) replacement in methimazole-treated monkeys was associated with the pubertal rise in LH in the remaining three animals and accelerated somatic development in all six animals. Although pubertal resurgence in LH secretion occurred at a later chronological age in methimazole-treated animals compared to controls, bone age, crown-rump length and body weight at that time did not differ between groups. There were no long-term differences in plasma prolactin between groups. We conclude that juvenile hypothyroidism in male primates causes a marked delay in the pubertal resurgence of LH secretion, probably occasioned at the hypothalamic level. Whether this effect is meditated by an action of thyroid hormone directly on the hypothalamus or indirectly as a result of the concomitant deficit in

  7. Prenatal and pubertal testosterone affect brain lateralization

    NARCIS (Netherlands)

    Beking, T; Geuze, R H; van Faassen, M; Kema, I P; Kreukels, B P C; Groothuis, T G G

    After decades of research, the influence of prenatal testosterone on brain lateralization is still elusive, whereas the influence of pubertal testosterone on functional brain lateralization has not been investigated, although there is increasing evidence that testosterone affects the brain in

  8. Peri-pubertal gonadotropin-releasing hormone agonist treatment affects sex biased gene expression of amygdala in sheep.

    Science.gov (United States)

    Nuruddin, Syed; Krogenæs, Anette; Brynildsrud, Ola Brønstad; Verhaegen, Steven; Evans, Neil P; Robinson, Jane E; Haraldsen, Ira Ronit Hebold; Ropstad, Erik

    2013-12-01

    The nature of hormonal involvement in pubertal brain development has attracted wide interest. Structural changes within the brain that occur during pubertal development appear mainly in regions closely linked with emotion, motivation and cognitive functions. Using a sheep model, we have previously shown that peri-pubertal pharmacological blockade of gonadotropin releasing hormone (GnRH) receptors, results in exaggerated sex-differences in cognitive executive function and emotional control, as well as sex and hemisphere specific patterns of expression of hippocampal genes associated with synaptic plasticity and endocrine signaling. In this study, we explored effects of this treatment regime on the gene expression profile of the ovine amygdala. The study was conducted with 30 same-sex twin lambs (14 female and 16 male), half of which were treated with the GnRH agonist (GnRHa) goserelin acetate every 4th week, beginning before puberty, until approximately 50 weeks of age. Gene expression profiles of the left and right amygdala were measured using 8×15 K Agilent ovine microarrays. Differential expression of selected genes was confirmed by qRT-PCR (Quantitative real time PCR). Networking analyses and Gene Ontology (GO) Term analyses were performed with Ingenuity Pathway Analysis (IPA), version 7.5 and DAVID (Database for Annotation, Visualization and integrated Discovery) version 6.7 software packages, respectively. GnRHa treatment was associated with significant sex- and hemisphere-specific differential patterns of gene expression. GnRHa treatment was associated with differential expression of 432 (|logFC|>0.3, adj. p value expressed as a result of GnRHa treatment in the male animals. The results indicated that GnRH may, directly and/or indirectly, be involved in the regulation of sex- and hemisphere-specific differential expression of genes in the amygdala. This finding should be considered when long-term peri-pubertal GnRHa treatment is used in children. Copyright

  9. The Few, the Changing, the Different: Pubertal Onset, Perceived School Climate and Body Image in Ethnically Diverse Sixth Grade Girls

    OpenAIRE

    Morales, Jessica

    2012-01-01

    The present study examined the impact of pubertal onset, race/ethnicity, and school racial/ethnic composition on girls' body image and perceived school climate (school safety, school liking, and loneliness in school) during the middle school transition. The sample (N = 1,626) included 6th grade Black, Mexican American, White, and Asian girls from 20 diverse middle schools. Hierarchical analyses supported both the early-timing and stressful change hypothesis. That is, experiencing pubertal ons...

  10. Pubertal status, interaction with significant others, and self-esteem of adolescent girls.

    Science.gov (United States)

    Lacković-Grgin, K; Dekovíc, M; Opacić, G

    1994-01-01

    The aim of this study was to examine the relationship between pubertal status, the quality of interactions with significant others, and the self-esteem of adolescent girls. The model which was tested, hypothesized that pubertal status affects self-esteem through girls' interactions with their parents and friends. Pubertal status was operationalized as the number of months between occurrence of the first menstrual periods and time of the investigation. The measure of self-esteem was the shortened form of the Coopersmith Self-Esteem Inventory. Analyses revealed that girls who begun menstruating six months before the investigation obtained higher scores on the measure of self-esteem than did girls who had been menstruating 13 months or more. The best predictor of self-esteem, however, was the quality of interaction with their mothers. The results support the theoretical view that stresses the importance of interaction with significant others for the development of self-esteem.

  11. Electro convulsive therapy in a pre-pubertal child with severe depression.

    Directory of Open Access Journals (Sweden)

    Russell P

    2002-10-01

    Full Text Available Electro Convulsive Therapy (ECT in pre-pubertal children is a controversial and underreported treatment. Even though the effectiveness and side effects of ECT in adolescents are comparable with those in adults, there is a pervasive reluctance to use ECT in children and adolescents. We report the case of a pre-pubertal child in an episode of severe depression with catatonic features, where a protracted course of ECT proved life-saving in spite of prolonged duration of seizures and delayed response to treatment. The case illustrates the safety and efficacy of ECT in children. Relevant literature is also reviewed along with the case report.

  12. Dietary polyunsaturated fatty acid supplementation of young post-pubertal dairy bulls alters the fatty acid composition of seminal plasma and spermatozoa but has no effect on semen volume or sperm quality.

    Science.gov (United States)

    Byrne, C J; Fair, S; English, A M; Holden, S A; Dick, J R; Lonergan, P; Kenny, D A

    2017-03-01

    The aim of this study was to examine the effects of dietary supplementation with rumen protected n-6 or n-3 polyunsaturated fatty acids (PUFA) on the quantity and quality of semen from young post-pubertal dairy bulls. Pubertal Holstein-Friesian (n = 43) and Jersey (n = 7) bulls with a mean ± s.e.m. age and bodyweight of 420.1 ± 5.86 days and 382 ± 8.94 kg, respectively, were blocked on breed, weight, age and semen quality (based on the outcomes of two pre-trial ejaculates) and randomly assigned to one of three treatments: (i) a non-supplemented control (CTL, n = 15), (ii) rumen-protected safflower (SO, n = 15), (iii) rumen-protected n-3 PUFA-enriched fish oil (FO, n = 20). Bulls were fed their respective diets, ad libitum for 12 weeks; individual intakes were recorded using an electronic feeding system for the initial 6 weeks of the feeding period. Semen was collected via electro-ejaculation at weeks -2, -1, 0, 7, 10, 11 and 12 relative to the beginning of the trial period (week 0). On collection, semen volume, sperm concentration and progressive linear motility (PLM) were assessed. On weeks -2, -1, 0, 10, 11, 12, semen was packaged into 0.25 mL straws and frozen using a programmable freezer. On weeks -1, 7 and 11; a sub-sample of semen was separated into sperm and seminal plasma, by centrifugation and stored at - 20 °C until analysis of lipid composition. Semen from 10 bulls per treatment were used for post-thaw analysis at weeks 10, 11 and 12 (3 straws per ejaculate). Sperm motility was analysed by computer assisted semen analysis (CASA). In addition, membrane fluidity, acrosome reaction and oxidative stress were assessed using flow cytometry. Sperm from bulls fed SO had a 1.2 fold higher total n-6 PUFA content at week 11 compared to week -1 (P semen volume, concentration or PLM of sperm when assessed either immediately following collection or post-thawing. Membrane fluidity and oxidative stress of sperm were also not affected by

  13. Maths performance as a function of sex, laterality, and age of pubertal onset.

    Science.gov (United States)

    Sappington, John; Topolski, Richard

    2005-07-01

    Sex differences in math/spatial performance demand explanations. Within the biological view, the complexity and number of variables make the explanation difficult at best. Laterality and age of pubertal onset have been investigated prominently in this context but rarely considered as interactions in the same study. Some 468 college subjects with SAT MATH (SAT M) scores were divided into 12 groups defined by sex, laterality, and age (early, middle, and late) of pubertal onset. Significant main effects for sex and age of onset emerged, as did an interaction between lateral preference and pubertal onset. Generally males outperformed females. The combination of maleness, sinistrality, and early maturation was associated with high SAT M scores. Sinistrality and late maturation among females predicted very poor math performance.

  14. Pubertal Onset in Apparently Healthy Indian Boys and Impact of Obesity.

    Science.gov (United States)

    Surana, Vineet; Dabas, Aashima; Khadgawat, Rajesh; Marwaha, Raman Kumar; Sreenivas, V; Ganie, M Ashraf; Gupta, Nandita; Mehan, Neena

    2017-01-01

    Primary - to determine the age of pubertal onset in Indian boys. Secondary - (a) to assess the impact of obesity on pubertal timing, (b) to assess the relationship between gonadotropins and puberty. Cross-sectional. General community-seven schools across New Delhi. Random sample of 1306 school boys, aged 6-17 years. Anthropometric measurement for weight and height and pubertal staging was performed for all subjects. Body mass index (BMI) was calculated to define overweight/obesity. Serum luteinizing hormone (LH), follicle stimulating hormone, and serum testosterone were measured in every sixth subject. Age at pubertal onset-testicular volume ≥4 mL (gonadarche) and pubic hair Stage II. Median age of attaining gonadarche and pubarche was 10.41 years (95% confidence interval [CI]: 10.2-10.6 years) and 13.60 (95% CI: 13.3-14.0 years), respectively. No significant difference in the age of attainment of gonadarche was observed in boys with normal or raised BMI, though pubarche occurred 8 months earlier in the latter group. Serum gonadotropins and testosterone increased with increasing stages of puberty but were unaffected by BMI. Serum LH level of 1.02 mIU/mL and testosterone level of >0.14 ng/mL showed the best prediction for pubertal onset. The study establishes a secular trend of the age of onset of puberty in Indian boys. Pubarche occurred earlier in overweight/obese boys. The cutoff levels of serum LH and testosterone for prediction of pubertal onset have been established.

  15. Validity of self-assessment of pubertal maturation

    DEFF Research Database (Denmark)

    Rasmussen, Anna; Wohlfahrt-Veje, Christine; Tefre de Renzy-Martin, Katrine

    2015-01-01

    BACKGROUND AND OBJECTIVES: Studies of adolescents often use self-assessment of pubertal maturation, the reliability of which has shown conflicting results. We aimed to examine the reliability of child and parent assessments of healthy boys and girls. METHODS: A total of 898 children (418 girls, 480...... overestimated older than their peers who made correct assessments. Girls and their parents tended to underestimate, whereas boys overestimated their pubertal stage. CONCLUSIONS: Pubertal assessment by the child or the parents is not a reliable measure of exact pubertal staging and should be augmented...

  16. Tamoxifen treatment for pubertal gynecomastia in two siblings with partial androgen insensitivity syndrome.

    Science.gov (United States)

    Saito, Reiko; Yamamoto, Yukiyo; Goto, Motohide; Araki, Shunsuke; Kubo, Kazuyasu; Kawagoe, Rinko; Kawada, Yasusada; Kusuhara, Koichi; Igarashi, Maki; Fukami, Maki

    2014-01-01

    Although tamoxifen has been shown to be fairly safe and effective for idiopathic pubertal gynecomastia, it remains unknown whether it is also beneficial for gynecomastia associated with endocrine disorders. Here, we report the effect of tamoxifen on pubertal gynecomastia in 2 siblings with partial androgen insensitivity syndrome (PAIS). Cases 1 and 2 presented with persistent pubertal gynecomastia at 13 and 16 years of age, respectively. Physical examinations revealed breast of Tanner stage 3 and normal male-type external genitalia in both cases. Clinical features such as female-type pubic hair and borderline small testis indicated mildly impaired masculinization. Molecular analysis identified a previously reported p.Arg789Ser mutation in the androgen receptor gene (AR) in the 2 cases. Two months of oral administration of tamoxifen ameliorated gynecomastia to Tanner stage 2 with no adverse events. Additional treatment with testosterone enanthate showed negligible effects on body hair and penile length. Hormone values of the 2 cases during tamoxifen treatment remained similar to those in previously reported untreated patients with PAIS. The results indicate that tamoxifen was effective in treating pubertal gynecomastia in these 2 patients with PAIS and may be considered as a therapeutic option in this situation pending further studies.

  17. Arthrospira (Spirulina) platensis supplementation affects folliculogenesis, progesterone and ghrelin levels in fattening pre-pubertal gilts

    NARCIS (Netherlands)

    Abadjieva, Desislava; Nedeva, Radka; Marchev, Yordan; Jordanova, Gergana; Chervenkov, Mihail; Dineva, Julieta; Shimkus, Almantas; Shimkiene, Aldona; Teerds, Katja; Kistanova, Elena

    2018-01-01

    The aim of the present investigation was to study the effect of Arthrospira (Spirulina) platensis supplemented diet on follicular development and related endocrine parameters, such as estradiol and progesterone levels as well as ghrelin levels in pre-pubertal gilts. Twenty-one 60-day-old Danube

  18. Investigation of pre-pubertal sex differences in wheel running and social behavior in three mouse strains.

    Science.gov (United States)

    Gordon, Elizabeth A; Corbitt, Cynthia

    2015-08-01

    Sex differences in social behaviors exist in mammals during adulthood, and further evidence suggests that sex differences in behavior are present before sexual maturity. In order to model behavioral disorders in animals, it is important to assess baseline sex-related behavioral differences, especially when studying disorders for which sex-related behavioral effects are expected. We investigated the effect of sex on behavior in 3 strains of pre-pubertal mice (C57BL/6, CFW, and CF1) using a wheel-running assay. We found no significant sex differences in latency to run on the wheel or total duration of wheel running within each strain. During the social interaction test, there were no differences between sexes in latency or total duration of contact or following between a subject and novel mouse. We also evaluated behavioral patterns of wheel running and stereotypical behaviors, such as burrowing and grooming. Both sexes showed characteristic wheel running behavior, spending the majority of each trial interacting with the wheel when it was free and more time performing other activities ( e.g. , stereotypical behaviors, general locomotion) when it was jammed. These results provide evidence that, among various strains of pre-pubertal mice, baseline sex-related behavioral differences are not strong enough to influence the measured behaviors.

  19. Repeatability and accuracy of reproductive tract scoring to determine pubertal status in beef heifers.

    Science.gov (United States)

    Rosenkrans, Kelly S; Hardin, David K

    2003-03-01

    The objective of this study was to compare the repeatability and accuracy of palpation per rectum to transrectal ultrasonography and serum progesterone concentrations for determining pubertal status in beef heifers. One hundred and seventy-four rectal examinations were performed on 29 predominantly Angus heifers by two veterinarians (A and B) and assigned individual reproductive tract scores (RTS) during monthly examinations over a 3-month period. Heifers were examined in the morning by both veterinarians, randomized, and re-examined in the afternoon. The size and location of ovarian structures of each heifer were determined by ultrasonography. Heifers with follicles >10mm in diameter or corpora lutea were classified as pubertal. Serum progesterone concentrations at the time of the examination and 10 days later were determined by radioimmunoassay and used to classify heifers as prepubertal (or=1 ng/ml). Kappa, which describes degree of agreement beyond chance, was used to determine repeatability of the RTS system. Multicategory Kappa for agreement was 0.64 within veterinarian, 0.46 between veterinarian, and 0.35 between palpation per rectum and transrectal ultrasonography. Sensitivity and specificity of palpation per rectum for diagnosis of pubertal status compared to serum progesterone levels were higher (82 and 69%, respectively) than sensitivity and specificity of ultrasonography (79 and 59%, respectively). This study validates the RTS system as a repeatable and accurate screening test to evaluate pubertal status in groups of heifers prior to the onset of the breeding season.

  20. Effect of timing on the outcomes of 1-phase nonextraction therapy of Class II malocclusion.

    Science.gov (United States)

    Baccetti, Tiziano; Franchi, Lorenzo; Kim, Ludia H

    2009-10-01

    The aim of this cephalometric study was to evaluate the role of timing in relation to skeletal maturity on the outcomes of nonextraction comprehensive Class II therapy. Three samples of patients with Class II Division 1 malocclusion were treated with headgear combined with fixed appliances and Class II elastics. Lateral cephalograms were taken of all subjects before therapy (T1) and at an average interval of 6 months after therapy (T2). The first sample (23 subjects) was treated before the pubertal growth spurt, the second sample (24 subjects) received therapy during the pubertal growth spurt, and the third sample (13 subjects) was treated at a postpubertal stage of development. The average T1 to T2 interval was approximately 30 months for all patients, with an average treatment duration of 24 months. Longitudinal observations of a group of 17 subjects with untreated Class II malocclusions were compared with the treated groups at the 3 skeletal maturation intervals with nonparametric statistics. Class II treatment before or during the pubertal growth spurt induced significant favorable skeletal changes (restricted maxillary advancement in prepubertal patients and enhanced mandibular growth in pubertal patients). Patients treated after the pubertal growth spurt had only significant dentoalveolar changes. The greatest amount of dentoskeletal correction of Class II malocclusion with 1-phase nonextraction treatment occurred in patients treated during the pubertal growth spurt.

  1. Pubertal development in The Netherlands 1965-1997

    NARCIS (Netherlands)

    D. Mul (Dick); A.M. Fredriks; S. van Buuren (Stef); W. Oostdijk (Wilma); S.P. Verloove-Vanhorick; J.M. Wit (Jan)

    2001-01-01

    textabstractWe investigated pubertal development of 4019 boys and 3562 girls >8 y of age participating in a cross-sectional survey in The Netherlands and compared the results with those of two previous surveys. Reference curves for all pubertal stages were constructed. The 50th

  2. Brain Maturation, Cognition and Voice Pattern in a Gender Dysphoria Case under Pubertal Suppression.

    Science.gov (United States)

    Schneider, Maiko A; Spritzer, Poli M; Soll, Bianca Machado Borba; Fontanari, Anna M V; Carneiro, Marina; Tovar-Moll, Fernanda; Costa, Angelo B; da Silva, Dhiordan C; Schwarz, Karine; Anes, Maurício; Tramontina, Silza; Lobato, Maria I R

    2017-01-01

    Introduction: Gender dysphoria (GD) (DMS-5) is a condition marked by increasing psychological suffering that accompanies the incongruence between one's experienced or expressed gender and one's assigned gender. Manifestation of GD can be seen early on during childhood and adolescence. During this period, the development of undesirable sexual characteristics marks an acute suffering of being opposite to the sex of birth. Pubertal suppression with gonadotropin releasing hormone analogs (GnRHa) has been proposed for these individuals as a reversible treatment for postponing the pubertal development and attenuating psychological suffering. Recently, increased interest has been observed on the impact of this treatment on brain maturation, cognition and psychological performance. Objectives: The aim of this clinical report is to review the effects of puberty suppression on the brain white matter (WM) during adolescence. WM Fractional anisotropy, voice and cognitive functions were assessed before and during the treatment. MRI scans were acquired before, and after 22 and 28 months of hormonal suppression. Methods: We performed a longitudinal evaluation of a pubertal transgender girl undergoing hormonal treatment with GnRH analog. Three longitudinal magnetic resonance imaging (MRI) scans were performed for diffusion tensor imaging (DTI), regarding Fractional Anisotropy (FA) for regions of interest analysis. In parallel, voice samples for acoustic analysis as well as executive functioning with the Wechsler Intelligence Scale (WISC-IV) were performed. Results: During the follow-up, white matter fractional anisotropy did not increase, compared to normal male puberty effects on the brain. After 22 months of pubertal suppression, operational memory dropped 9 points and remained stable after 28 months of follow-up. The fundamental frequency of voice varied during the first year; however, it remained in the female range. Conclusion: Brain white matter fractional anisotropy

  3. Reproductive ability of pubertal male and female rats

    Directory of Open Access Journals (Sweden)

    T. Zemunik

    2003-07-01

    Full Text Available Ten Fisher rats 50 to 55 days of age made up the pubertal group, and ten rats 90 to 95 days of age served as the controls. The testicular and epididymal weights and volumes of the pubertal males were lower than those of the controls (P0.05. At the beginning of gestation, the pubertal dams weighed less than the controls (P<0.001 but following uterectomy the body weights were equal. Pubertal dams delivered fewer pups than the controls (8.1 ± 2.5 vs 10.4 ± 1.3, P<0.05. There was no difference in the body weights of their offspring or in the weights of their placentas. The results suggest that, in contrast to their female counterparts, pubertal male rats are not fully mature and have not reached complete reproductive capacity at 50-55 days of age.

  4. Course and forecast of the hypothalamic pubertal syndrome

    International Nuclear Information System (INIS)

    Kayusheva, I.V.

    1987-01-01

    A total of 223 patients with the hypothalamic pubertal syndrome (HPS) were followed up for 1 to 22 years. The course of HPS was regressive, stable , recurrent or progressive and dependent on the initial depth and spread of hypothalamic lesion, repeated unfavourable hypothalamic exposures, and timely and regular treatment. HPS outcomes were followed up in 190 cases. The recovery was complete in 21.05%, obesity alone persisted in 10.53%, vegetovascular dystonia was persistent in 7.36%, and polycystic ovaries in 5.79%. Neuroendocrine hypothalamic syndrome was the most common (50.53%) HPS outcome. Hormone levels in blood were investigated using radioimmunoassay in patients with neuroendocrine form of HPS

  5. Serum inhibin B in healthy pubertal and adolescent boys

    DEFF Research Database (Denmark)

    Andersson, A M; Juul, A; Petersen, J H

    1997-01-01

    correlated strongly with age, and when the effect of age was taken into account, only the partial correlation between inhibin B and LH/testosterone remained statistically significant. At stage II of puberty, the positive partial correlation between inhibin B and LH/testosterone was still present. At stage......Inhibin B levels were measured in serum from 400 healthy Danish prepubertal, pubertal, and adolescent males, aged 6-20 yr, in a cross-sectional study using a recently developed immunoassay that is specific for inhibin B, the physiologically important inhibin form in men. In addition, serum levels...... of FSH, LH, testosterone, and estradiol levels were measured. Serum levels of inhibin B, FSH, LH, testosterone, and estradiol all increased significantly between stages I and II of puberty. From stage II of puberty the inhibin B level was relatively constant, whereas the FSH level continued to increase...

  6. The long-term effects of FSH and triiodothyronine administration during the pubertal period on Connexin 43 expression and spermatogenesis efficiency in adult rats.

    Science.gov (United States)

    Marchlewska, Katarzyna; Slowikowska-Hilczer, Jolanta; Walczak-Jedrzejowska, Renata; Oszukowska, Elzbieta; Filipiak, Eliza; Kula, Krzysztof

    2015-04-01

    Follicle-stimulating hormone (FSH) and triiodothyronine (T3) are known regulatory factors of spermatogenesis initiation. Hyperstimulation of both hormones evokes regressional changes in connexin 43 expression and the seminiferous epithelium in young rats during testicular maturation. However, separate treatments with T3 reduce Sertoli cell number, which seems to be closely connected with the maturation of connexin 43 gap junctions. FSH elevates Sertoli cell number and function, but this effect may take place regardless of the presence of connexin 43-dependent intercellular communication. The aim of the study was to evaluate the later effects of such treatments. Newborn, male Wistar rats were divided randomly into experimental groups receiving daily subcutaneous injections of either 7.5 IU/animal FSH, or 100 mg/kg b.w. T3, or both substances or the same volume of vehicle (control group) until day 15 of life. The animals were sacrificed on day 50. Morphometric analysis and immunohistochemical reactions were performed using antibodies against Vimentin, Proliferating Cell Nuclear Antigen and Connexin 43 in the testis. Sertoli cell count, efficiency of spermatogenesis, and hormonal pattern were examined. Disturbances in the connexin 43 expression reduced the number of Sertoli cells, the efficiency of spermatogenesis and impaired endocrine function of testes in adult rats treated with FSH and T3 during puberty. Stimulation with FSH alone increased Sertoli cell number, but was associated with a negative effect on cell-to-cell connexin 43-dependent communication, with a consequential reduction of spermatogenesis efficiency. J. Exp. Zool. 323A: 256-265, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  7. Pubertal development and prostate cancer risk

    DEFF Research Database (Denmark)

    Bonilla, Carolina; Lewis, Sarah J; Martin, Richard M

    2016-01-01

    , 0.91-1.00) and prostate cancer-specific mortality (hazard ratio amongst cases, per tertile: 0.94; 95 % CI, 0.90-0.98), but not with disease grade. CONCLUSIONS: Older age at sexual maturation is causally linked to a reduced risk of later prostate cancer, especially aggressive disease.......BACKGROUND: Epidemiological studies have observed a positive association between an earlier age at sexual development and prostate cancer, but markers of sexual maturation in boys are imprecise and observational estimates are likely to suffer from a degree of uncontrolled confounding. To obtain...... to a difference of one Tanner stage between pubertal boys of the same age) was associated with a 77 % (95 % CI, 43-91 %) reduced odds of high Gleason prostate cancer. In PRACTICAL, the puberty genetic score was associated with prostate cancer stage (OR of advanced vs. localized cancer, per tertile: 0.95; 95 % CI...

  8. The effect of dairy intake on bone mass and body composition in early pubertal girls and boys: a randomized controlled trial.

    Science.gov (United States)

    Vogel, Kara A; Martin, Berdine R; McCabe, Linda D; Peacock, Munro; Warden, Stuart J; McCabe, George P; Weaver, Connie M

    2017-05-01

    Background: Calcium retention increases with increasing body mass index (BMI) on recommended calcium intakes. Dairy foods are an excellent source of essential nutrients that are needed to increase bone mineral content (BMC) and potentially decrease fracture. Objective: We compared children who were overweight with children who were healthy weight for the accrual of bone mass in response to an extra 3 servings dairy/d compared with usual intake. Design: Participants were 240 healthy boys and girls (64%), aged 8-15.9 y (mean ± SD age: 11.8 ± 1.5 y), who consumed low amounts of dairy (hip were observed between subjects who received the dairy intervention (achieved consumption of 1500 mg Ca/d) and subjects who did not (achieved 1000 mg Ca/d, which represented ∼2 cups milk or other dairy as part of the diet) with the exception of a tibial BMC gain, which was greater in the group who were given dairy ( P = 0.02). Body fat was not influenced by the diet assignment. Conclusions: Dairy food interventions generally had no effect on bone mineral acquisition or body composition either within or between weight groups. This study suggests that 2 cups milk or the dairy equivalent is adequate for normal bone gain between ages 8 and 16 y. This trial was registered at clinicaltrials.gov as NCT00635583. © 2017 American Society for Nutrition.

  9. Male pre- and post-pubertal castration effect on live weight, components of empty body weight, estimated nitrogen excretion and efficiency in Piemontese hypertrofic cattle

    Directory of Open Access Journals (Sweden)

    Davide Biagini

    2011-04-01

    Full Text Available To evaluate the effect of sexual neutering and age of castration on empty body weight (EBW components and estimated nitrogen excretion and efficiency, a trial was carried out on 3 groups of double-muscled Piemontese calves: early castrated (EC, 5th month of age, late castrated (LC, 12th month of age and intact males (IM, control group. Animals were fed at the same energy and protein level and slaughtered at 18th month of age. Live and slaughtering performances and EBW components were recorded, whereas N excretion was calculated by difference between diet and weight gain N content. In live and slaughtering performances, IM showed higher final, carcass and total meat weight than EC and LC (P<0.01. In EBW components, IM showed higher blood and head weight than EC and LC (P<0.01 and 0.05 respectively, and differences were found between EC and LC for head weights (P<0.01. IM showed higher body crude protein (BCP than EC and LC (P<0.01 and 0.05 respectively, but BCP/EBW ratio was higher only in IM than EC (P<0.05. Estimated N daily gain was higher in IM than EC and LC (P<0.01. Only LC showed higher excretion than IM (P<0.05, and N efficiency was higher in IM than EC and LC (P<0.05 and 0.01 respectively. In conclusion, for the Piemontese hypertrophied cattle castration significantly increases N excretion (+7% and reduces N efficiency (-15%, leading to a lower level of sustainability.

  10. Ovarian function following pelvic irradiation in prepubertal and pubertal girls and young adult women

    International Nuclear Information System (INIS)

    Schuck, A.; Hamelmann, V.; Braemswig, J.H.

    2005-01-01

    Purpose: To analyze the effect of pelvic radiotherapy on ovarian function in prepubertal and pubertal girls and young adult women. Patients and methods: In a retrospective monoinstitutional analysis, patients 15 Gy to the ovaries developed hormone failure. In one case of a patient receiving an ovarian dose of 15 Gy, hormone failure was not found. In case of pelvic irradiation excluding at least one ovary, approximately half of the patients developed ovarian dysfunction, probably also due to the effects of polychemotherapy. (orig.)

  11. Exciting fear in adolescence: Does pubertal development alter threat processing?

    OpenAIRE

    Spielberg, JM; Olino, TM; Forbes, EE; Dahl, RE

    2014-01-01

    Adolescent development encompasses an ostensible paradox in threat processing. Risk taking increases dramatically after the onset of puberty, contributing to a 200% increase in mortality. Yet, pubertal maturation is associated with increased reactivity in threat-avoidance systems. In the first part of this paper we propose a heuristic model of adolescent affective development that may help to reconcile aspects of this paradox, which focuses on hypothesized pubertal increases in the capacity t...

  12. Pubertal stage and the prevalence of violence and social relational aggression

    Science.gov (United States)

    Hemphill, Sheryl A.; Kotevski, Aneta; Herrenkohl, Todd I.; Toumbourou, John W.; Carlin, John B.; Catalano, Richard F.; Patton, George C.

    2010-01-01

    Objective Violence and social relational aggression are global problems that become prominent in early adolescence. This study examines associations between pubertal stage and adolescent violent behavior and social relational aggression. Methods This paper draws on cross-sectional data from the International Youth Development Study (IYDS), which comprised two state-wide representative samples of students in grades 5, 7 and 9 (N = 5,769) in Washington State in the United States and Victoria, Australia, drawn as a 2-stage cluster sample in each state. The study used carefully matched methods to conduct a school-administered, self-report student survey measuring behavioral outcomes including past year violent behavior (measured as attacking or beating up another person) and social relational aggression (excluding peers from the group, threatening to spread lies or rumors), as well as a comprehensive range of risk and protective factors and pubertal development. Results Compared with early puberty, the odds of violent behavior were approximately three-fold higher in mid-puberty (odds ratio [OR]: 2.87; 95% confidence interval [CI]: 1.81,4.55) and late puberty (OR: 3.79; 95% CI: 2.25,6.39), after adjustment for age, gender, state, and state by gender interaction. For social relational aggression, there were weaker overall associations after adjustment but these included an interaction between pubertal stage and age, showing stronger associations with pubertal stage at younger age (p = .003; mid-puberty OR 1.78; 95% CI 1.20,2.63; late puberty OR 3.00; 95% CI 1.95,4.63. Associations between pubertal stage and violent behavior and social relational aggression remained (although the magnitude of effects was reduced), after the inclusion of social contextual mediators in the analyses. Conclusions Pubertal stage was associated with higher rates of violent behavior and social relational aggression, with the latter association seen only at younger ages. Puberty may be an

  13. Early pubertal onset and its relationship with sexual risk taking, substance use and anti-social behaviour: a preliminary cross-sectional study

    Directory of Open Access Journals (Sweden)

    Bellis Mark A

    2009-12-01

    Full Text Available Abstract Background In many countries age at pubertal onset has declined substantially. Relatively little attention has been paid to how this decline may affect adolescent behaviours such as substance use, violence and unprotected sex and consequently impact on public health. Methods In the UK, two opportunistic samples (aged 16-45 years, paper-based (n = 976 and online (n = 1117, examined factors associated with earlier pubertal onset and whether earlier age of onset predicted sexual risk-taking, substance use and anti-social behaviours during early adolescence. Results Overall, 45.6% of females reported menarche ≤ 12 years and 53.3% of males were categorised as having pubertal onset ≤ 11 years. For both sexes earlier pubertal onset was associated with poorer parental socio-economic status. Other pre-pubertal predictors of early onset were being overweight, more childhood illnesses (females and younger age at time of survey (males. For both sexes earlier puberty predicted having drunk alcohol, been drunk, smoked and used drugs Conclusion Results provide sufficient evidence for changes in age of pubertal onset to be further explored as a potential influence on trends in adolescent risk behaviours. Further insight into the relationship between early puberty and both obesity and socio-economic status may help inform early interventions to tackle the development of risk behaviours and health inequalities during early adolescence.

  14. Physical activity reduces systemic blood pressure and improves early markers of atherosclerosis in pre-pubertal obese children.

    Science.gov (United States)

    Farpour-Lambert, Nathalie J; Aggoun, Yacine; Marchand, Laetitia M; Martin, Xavier E; Herrmann, François R; Beghetti, Maurice

    2009-12-15

    The aim of this study was to determine the effects of physical activity on systemic blood pressure (BP) and early markers of atherosclerosis in pre-pubertal obese children. Hypertension and endothelial dysfunction are premature complications of obesity. We performed a 3-month randomized controlled trial with a modified crossover design: 44 pre-pubertal obese children (age 8.9 + or - 1.5 years) were randomly assigned (1:1) to an exercise (n = 22) or a control group (n = 22). We recruited 22 lean children (age 8.5 + or - 1.5 years) for baseline comparison. The exercise group trained 60 min 3 times/week during 3 months, whereas control subjects remained relatively inactive. Then, both groups trained twice/week during 3 months. We assessed changes at 3 and 6 months in office and 24-h BP, arterial intima-media thickness (IMT) and stiffness, endothelial function (flow-mediated dilation), body mass index (BMI), body fat, cardiorespiratory fitness (maximal oxygen consumption [VO(2)max]), physical activity, and biological markers. Obese children had higher BP, arterial stiffness, body weight, BMI, abdominal fat, insulin resistance indexes, and C-reactive protein levels, and lower flow-mediated dilation, VO(2)max, physical activity, and high-density lipoprotein cholesterol levels than lean subjects. At 3 months, we observed significant changes in 24-h systolic BP (exercise -6.9 + or - 13.5 mm Hg vs. control 3.8 + or - 7.9 mm Hg, -0.8 + or - 1.5 standard deviation score [SDS] vs. 0.4 + or - 0.8 SDS), diastolic BP (-0.5 + or - 1.0 SDS vs. 0 + or - 1.4 SDS), hypertension rate (-12% vs. -1%), office BP, BMI z-score, abdominal fat, and VO(2)max. At 6 months, change differences in arterial stiffness and IMT were significant. A regular physical activity program reduces BP, arterial stiffness, and abdominal fat; increases cardiorespiratory fitness; and delays arterial wall remodeling in pre-pubertal obese children. (Effects of Aerobic Exercise Training on Arterial Function and

  15. School performance in pubertal adolescents with dysmenorrhea

    Directory of Open Access Journals (Sweden)

    Syamsir Alam

    2011-08-01

    Full Text Available Background Dysmenorrhea is a common gynecological symptom reported in adolescent girls. Prevalence of the condition has been reported to be 45 - 75%. Absenteeism from work and school as a result of dysmenorrhea is common (13 - 51% of women have been absent at least once, and 5 - 14% are often absent due to the severity of symptoms. Objective To compare school performance in pubertal adolescent girls with and without dysmenorrhea. Methods This cross-sectional study was conducted in June 2010 in adolescent females aged 12 - 18 years from the Musthafawiyah School, Mandailing Natal district, North Sumatera. Adolescent females with and without dysmenorrhea were recruited for this study. All participants completed questionnaires including age of menarche, length of menstrual cycle, length of bleeding, number of sanitary napkins used daily and school absences. School reports from two consecutive semesters in one year were used to evaluate subjects’ academic performance. An academic score of higher than 7.5 was considered good performance while scores of less than 7.5 were considered poor. We used the chi-square test to analyze differences in school performance between girls with and without dysmenorrhea. Results One hundred and sixteen participants were divided into 2 groups, those with and without dysmenorrhea, of 58 subjects each. We found no significant difference in school performance between the two groups, P=0.176 (95% CI -0.009 to -0.048 and P=0.08 (95%CI -0.052 to 0.024. Conclusion There was no significant difference in school performance of girls with and without dysmenorrhea.

  16. Candidate gene expression in Bos indicus ovarian tissues: pre-pubertal and post-pubertal heifers in diestrus

    Directory of Open Access Journals (Sweden)

    Mayara Morena Del Cambre Amaral Weller

    2016-10-01

    Full Text Available Growth factors such as bone morphogenetic proteins 6, 7, 15 and two isoforms of transforming growth factor-beta (BMP6, BMP7, BMP15, TGFB1 and TGFB2 and insulin-like growth factor system act as local regulators of ovarian follicular development. To elucidate if these factors as well as others candidate genes such as estrogen receptor 1 (ESR1, growth differentiation factor 9 (GDF9, follicle stimulating hormone receptor (FSHR, luteinizing hormone receptor (LHR, bone morphogenetic protein receptor, type 2 (BMPR2, type 1 insulin-like growth factor receptor (IGFR1, and key steroidogenic enzymes cytochrome P450 aromatase and 3-β-hydroxysteroid dehydrogenase (CYP19A1 and HSD3B1 could modulate or influence diestrus on the onset of puberty in Brahman heifers, their ovarian mRNA expression was measured before and after puberty (luteal phase. Six post-pubertal (POST heifers were euthanized on the luteal phase of their second cycle, confirmed by corpus luteum observation, and six pre-pubertal (PRE heifers were euthanized in the same day. Quantitative real-time PCR analysis showed that the expression of FSHR, BMP7, CYP19A1, IGF1 and IGFR1 mRNA was greater in PRE heifers, when contrasted to POST heifers. The expression of LHR and HSD3B1 was lower in PRE heifers. Differential expression of ovarian genes could be associated with changes in follicular dynamics and different cell populations that have emerged as consequence of puberty and the luteal phase. The emerging hypothesis is that BMP7 and IGF1 are co-expressed and may modulate the expression of FSHR, LHR and IGFR1 and CYP19A1. BMP7 could influence the down-regulation of LHR and up-regulation of FSHR and CYP19A1, which mediates the follicular dynamics in heifer ovaries. Up-regulation of IGF1 expression pre-puberty, compared to post-puberty diestrus, correlates with increased levels FSHR and CYP19A1. Thus, BMP7 and IGF1 may play synergic roles and were predicted to interact, from the expression data (P = 0

  17. Pubertal induction in hypogonadism: Current approaches including use of gonadotrophins.

    Science.gov (United States)

    Zacharin, Margaret

    2015-06-01

    Primary disorders of the gonad or those secondary to abnormalities of the hypothalamic pituitary axis result in hypogonadism. The range of health problems of childhood and adolescence that affect this axis has increased, as most children now survive chronic illness, but many have persisting deficits in gonadal function as a result of their underlying condition or its treatment. An integrated approach to hormone replacement is needed to optimize adult hormonal and bone health, and to offer opportunities for fertility induction and preservation that were not considered possible in the past. Timing of presentation ranges from birth, with disorders of sexual development, through adolescent pubertal failure, to adult fertility problems. This review addresses diagnosis and management of hypogonadism and focuses on new management strategies to address current concerns with fertility preservation. These include Turner syndrome, and fertility presevation prior to childhood cancer treatment. New strategies for male hormone replacement therapy that may impinge upon future fertility are emphasized. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Individual differences in boys' and girls' timing and tempo of puberty: modeling development with nonlinear growth models.

    Science.gov (United States)

    Marceau, Kristine; Ram, Nilam; Houts, Renate M; Grimm, Kevin J; Susman, Elizabeth J

    2011-09-01

    Pubertal development is a nonlinear process progressing from prepubescent beginnings through biological, physical, and psychological changes to full sexual maturity. To tether theoretical concepts of puberty with sophisticated longitudinal, analytical models capable of articulating pubertal development more accurately, we used nonlinear mixed-effects models to describe both the timing and tempo of pubertal development in the sample of 364 White boys and 373 White girls measured across 6 years as part of the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development. Individual differences in timing and tempo were extracted with models of logistic growth. Differential relations emerged for how boys' and girls' timing and tempo of development were related to physical characteristics (body mass index, height, and weight) and psychological outcomes (internalizing problems, externalizing problems, and risky sexual behavior). Timing and tempo are associated in boys but not girls. Pubertal timing and tempo are particularly important for predicting psychological outcomes in girls but only sparsely related to boys' psychological outcomes. Results highlight the importance of considering the nonlinear nature of puberty and expand the repertoire of possibilities for examining important aspects of how and when pubertal processes contribute to development.

  19. Early Adolescent Friendship Selection Based on Externalizing Behavior: the Moderating Role of Pubertal Development. The SNARE Study.

    Science.gov (United States)

    Franken, Aart; Prinstein, Mitchell J; Dijkstra, Jan Kornelis; Steglich, Christian E G; Harakeh, Zeena; Vollebergh, Wilma A M

    2016-11-01

    This study examined friendship (de-)selection processes in early adolescence. Pubertal development was examined as a potential moderator. It was expected that pubertal development would be associated with an increased tendency for adolescents to select their friends based on their similarities in externalizing behavior engagement (i.e., delinquency, alcohol use, and tobacco use). Data were used from the first three waves of the SNARE (Social Network Analysis of Risk behavior in Early adolescence) study (N = 1144; 50 % boys; M age  = 12.7; SD = 0.47), including students who entered the first year of secondary school. The hypothesis was tested using Stochastic Actor-Based Modeling in SIENA. While taking the network structure into account, and controlling for peer influence effects, the results supported this hypothesis. Early adolescents with higher pubertal development were as likely as their peers to select friends based on similarity in externalizing behavior and especially likely to remain friends with peers who had a similar level of externalizing behavior, and thus break friendship ties with dissimilar friends in this respect. As early adolescents are actively engaged in reorganizing their social context, adolescents with a higher pubertal development are especially likely to lose friendships with peers who do not engage in externalizing behavior, thus losing an important source of adaptive social control (i.e., friends who do not engage in externalizing behavior).

  20. [Study on the pathogens correlated to sexually transmitted diseases in 285 pre-pubertal girls with vulvovaginitis in Beijing].

    Science.gov (United States)

    Liu, Xiao-Yan; Sun, Hong-Mei; Feng, Yan-Ling; Hu, Jin; Zhao, Han-Qing; Zhang, Li-Ya

    2007-08-01

    To study the relationship between vulvovaginitis in pre-pubertal girls and pathogens as Chlamydia trachomatis (Ct), N. gonorrhoeae (Ng), Mycoplasma, Ureaplasma urealyticum (Uu), Mycoplasma hominis (Mh), M. genitalium (Mg), M. fermentans (Mf) and M. penetrans (Mpe), as well as to find out the proportion of mycoplasma which is correlated to sexually transmitted diseases (STD) and AIDS. METHODS Vulvae swab specimens from 285 pre-pubertal girls with vulvovaginitis (case group) and 128 healthy girls (control group) were collected and detected by nested polymerase chain reaction (nPCR) to identify the existence of pathogens as Ct, Ng, Uu, Mh, Mg, Mf and Mpe. nPCR with both high specificity and sensitivity, would not be influenced by the amount of pathogens in specimens or inactivated during the process of storage or transportation. The rate of detection on pathogens was 59.65% in the 285 specimens from case group including 'one kind of pathogen in one specimen' as 37.54% and 'two kinds' as 16.84% and 'three kinds' as 5.26%. However, in the 128 specimens from control group, the detectable rate of pathogen was 6.25%. Relationships were found between Ng (P vulvovaginitis in pre-pubertal girls. In control group the pathogens were detected from 7 specimens including 5 Uu and 2 Mh. Some of the pathogens were correlated to STD and were important in causing vulvovaginitis in pre-pubertal girls. Vulvovaginitis might have been caused by more than one kind of pathogen in pre-pubertal girls. The locations of Mg, Mf and Ng in outer genital tracts were correlated to seasonal change. Macrolide seemed to be quite effective clinically in treating urogenital tract infection caused by mycoplasma and Ct.

  1. Serum inhibin B in healthy pubertal and adolescent boys

    DEFF Research Database (Denmark)

    Andersson, A M; Juul, A; Petersen, J H

    1997-01-01

    Inhibin B levels were measured in serum from 400 healthy Danish prepubertal, pubertal, and adolescent males, aged 6-20 yr, in a cross-sectional study using a recently developed immunoassay that is specific for inhibin B, the physiologically important inhibin form in men. In addition, serum levels...

  2. Melatonin and LH secretion patterns in pubertal boys

    International Nuclear Information System (INIS)

    Fevre, M.; Boyar, R.M.; Rollag, M.D.

    1979-01-01

    Plasma melatonin and LH were measured at 20 minute intervals for 24 hours in four normal pubertal boys. All four subjects showed a significant augmentation of LH and melatonin during nocturnal sleep. There was also a significant correlation between the LH and melatonin levels (p [fr

  3. Timely and Effective Care - National

    Data.gov (United States)

    U.S. Department of Health & Human Services — Timely and Effective Care measures - national data. This data set includes national-level data for measures of heart attack care, heart failure care, pneumonia care,...

  4. Timely and Effective Care - State

    Data.gov (United States)

    U.S. Department of Health & Human Services — Timely and Effective Care measures - state data. This data set includes state-level data for measures of heart attack care, heart failure care, pneumonia care,...

  5. Timely and Effective Care - Hospital

    Data.gov (United States)

    U.S. Department of Health & Human Services — Timely and Effective Care measures - provider data. This data set includes provider-level data for measures of cataract surgery outcome, colonoscopy follow-up, heart...

  6. Timely and Effective Care - State

    Data.gov (United States)

    U.S. Department of Health & Human Services — Timely and Effective Care measures - provider data. This data set includes state-level data for measures of cataract surgery outcome, colonoscopy follow-up, heart...

  7. Timely and Effective Care - National

    Data.gov (United States)

    U.S. Department of Health & Human Services — Timely and Effective Care measures - provider data. This data set includes national-level data for measures of cataract surgery outcome, colonoscopy follow-up, heart...

  8. Investigation of pre-pubertal sex differences in wheel running and social behavior in three mouse strains

    OpenAIRE

    Gordon, Elizabeth A.; Corbitt, Cynthia

    2015-01-01

    Sex differences in social behaviors exist in mammals during adulthood, and further evidence suggests that sex differences in behavior are present before sexual maturity. In order to model behavioral disorders in animals, it is important to assess baseline sex-related behavioral differences, especially when studying disorders for which sex-related behavioral effects are expected. We investigated the effect of sex on behavior in 3 strains of pre-pubertal mice (C57BL/6, CFW, and CF1) using a whe...

  9. The influence of chronic conditions and the environment on pubertal development. An example from medieval England.

    Science.gov (United States)

    Lewis, M E; Shapland, F; Watts, R

    2016-03-01

    Adolescence is a unique period in human development encompassing sexual maturation (puberty) and the physical and psychological transition into adulthood. It is a crucial time for healthy development and any adverse environmental conditions, poor nutrition, or chronic infection can alter the timing of these physical changes; delaying menarche in girls or the age of peak height velocity in boys. This study explores the impact of chronic illness on the tempo of puberty in 607 adolescent skeletons from medieval England (AD 900-1550). A total of 135 (22.2%) adolescents showed some delay in their pubertal development, and this lag increased with age. Of those with a chronic condition, 40.0% (n=24/60) showed delay compared to only 20.3% (n=111/547) of the non-pathology group. This difference was statistically significant. A binary logistic regression model demonstrated a significant association between increasing delay in pubertal stage attainment with age in the pathology group. This is the first time that chronic conditions have been directly associated with a delay in maturation in the osteological record, using a new method to assess stages of puberty in skeletal remains. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Time Limits : Effects on Recall

    OpenAIRE

    Hirano, Kinue

    2000-01-01

    This study investigates the effects of differing time limits and the level of language proficiency on the written recalls of 66 Japanese EFL undergraduates. Results showed that different time limits affected total recall, but not main ideas recalled. Regardless of proficiency level, the 20-minute group (Group 2) recalled a greater number of idea units than the 8-minute group (Group 1). However, no significant difference was found between Groups 1 and 2 regarding the recall of main ideas, alth...

  11. An unanswered question in pediatric urology: the post pubertal persistence of prepubertal congenital penile curvature correction by tunical plication.

    Science.gov (United States)

    Ozkuvanci, Ünsal; Ziylan, Orhan; Dönmez, M Irfan; Yucel, Omer Baris; Oktar, Tayfun; Ander, Haluk; Nane, Ismet

    2017-01-01

    The aim of this study is to analyze post pubertal results of pre pubertal tunica albuginea plication with non-absorbable sutures in the correction of CPC. The files of patients who underwent tunica albuginea plication without incision (dorsal/lateral) were retrospectively reviewed. Patients younger than 13 years of age at the time of operation and older than 14 years of age in November 2015 were included. Patients with a penile curvature of less than 30 degrees & more than 45 degrees and penile/urethral anomalies were excluded. All of the patients underwent surgery followed by circumcision. The mean age of patients at the time of the operation was 9.7 years (range, 6-13 years). The mean degree of ventral penile curvature measured during the operation was 39 degrees while it was 41 degrees in the lateral curvatures. All of the patients were curvature-free at the end of the operation. At the time of the follow-up examination, the mean age was 16.7 years (range, 14-25 years). Six patients had a straight (0-10 degrees) penis during erection and seven patients had recurrent penile curvatures ranging from 30 to 50 degrees. Pre pubertal tunica albuginea plication of congenital penile curvature (30-45 degrees) with non-absorbable sutures performed without incision is a minimal invasive method especially when performed during circumcision. However, recurrence might be observed in half of the patients after puberty. Copyright® by the International Brazilian Journal of Urology.

  12. An unanswered question in pediatric urology: the post pubertal persistence of prepubertal congenital penile curvature correction by tunical plication

    Directory of Open Access Journals (Sweden)

    Ünsal Ozkuvanci

    Full Text Available ABSTRACT Objective: The aim of this study is to analyze post pubertal results of pre pubertal tunica albuginea plication with non-absorbable sutures in the correction of CPC. Materials and Methods: The files of patients who underwent tunica albuginea plication without incision (dorsal/lateral were retrospectively reviewed. Patients younger than 13 years of age at the time of operation and older than 14 years of age in November 2015 were included. Patients with a penile curvature of less than 30 degrees & more than 45 degrees and penile/urethral anomalies were excluded. All of the patients underwent surgery followed by circumcision. Results: The mean age of patients at the time of the operation was 9.7 years (range, 6-13 years. The mean degree of ventral penile curvature measured during the operation was 39 degrees while it was 41 degrees in the lateral curvatures. All of the patients were curvature-free at the end of the operation. At the time of the follow-up examination, the mean age was 16.7 years (range, 14-25 years. Six patients had a straight (0-10 degrees penis during erection and seven patients had recurrent penile curvatures ranging from 30 to 50 degrees. Conclusion: Pre pubertal tunica albuginea plication of congenital penile curvature (30-45 degrees with non-absorbable sutures performed without incision is a minimal invasive method especially when performed during circumcision. However, recurrence might be observed in half of the patients after puberty.

  13. Female Pubertal Timing and Problem Behaviour: The Role of Culture

    Science.gov (United States)

    Skoog, Therese; Stattin, Hakan; Ruiselova, Zdena; Ozdemir, Metin

    2013-01-01

    We tested the peer-socialization/contextual-amplification explanation for the link between early female puberty and problem behaviour. We propose that in cultures with high tolerance for adolescent heterosexual involvement, early puberty should be linked with problem behaviour--not in other cultures. We compared girls in two cultures (Slovakia and…

  14. Timing effects on first marriage

    DEFF Research Database (Denmark)

    Schoen, Robert; Canudas-Romo, Vladimir

    2005-01-01

    Recent substantial declines in first marriage in Western countries have been accompanied by increases in the average age at first marriage. Since the period proportion ever marrying, PEM, is sensitive to cohort tempo changes, the recent fall in the PEM may simply reflect cohort delays in marriage....... The importance of timing factors is examined in the light of twentieth-century experience of first marriage in England and Wales and the USA. Using a variant of the Timing Index developed in research on fertility, we measure cohort timing effects for marriage and calculate an adjusted PEM. After examining...... twentieth-century trends in nuptiality for men and women, we find substantial tempo effects on the period PEM. Adjusted PEM values show a real decline in marriage for cohorts, but that decline is considerably smaller than the one shown by the unadjusted figures. This is especially true for England and Wales...

  15. Rope skipping increases bone mineral density at calcanei of pubertal girls in Hong Kong: A quasi-experimental investigation.

    Directory of Open Access Journals (Sweden)

    Amy S Ha

    Full Text Available Bone mineral accrual during puberty is important, especially in girls, because it is related to reduced risks of osteoporosis in adulthood. Previous research has shown that jumping or plyometric exercises may be effective in increasing bone mineral density in adolescents. Rope skipping is a form of activity that involves jumping, thus regular skipping may also increase bone mineral density in pubertal girls. To this end, we conducted a quasi-experimental to examine the effects of rope skipping on girls' bone mineral density and cardiovascular fitness. 176 Hong Kong girls (age = 12.23 ± 1.80 years at baseline were recruited to take part in the study. Bone density at their forearms and calcanei were measured twice over two academic years (mean time between visits was 10.3 months. Using multilevel modeling analyses and adjusting for participants' height and physical activity, we found that girls who participated in weekly rope skipping activities, compared to those who did not, had higher levels of bone density at the calcanei (B = 0.023, p < .01. However, no differences were found for bone density at forearms or participants' cardiovascular fitness. The rates of change of these variables across time were also not significantly different. Results suggest that regular rope skipping may increase girls' bone density at the lower extremities, irrespective of the amount of self-report physical activity. However, further research is required to examine the potential dose-response relation between skipping behaviors and the measured outcomes.

  16. Comparison of clinical and microbiological features of vulvovaginitis in prepubertal and pubertal girls.

    Science.gov (United States)

    Yilmaz, Ayse E; Celik, Nurullah; Soylu, Gul; Donmez, Ahsen; Yuksel, Cigdem

    2012-07-01

    Vulvovaginitisis the most common gynecological problem of childhood. The aim of the study was to determine and compare clinical and microbiological features of vulvovaginitis in prepubertal and adolescent girls. In this retrospective study, the records of patients who were diagnosed with vulvovaginitis between January 2005 and December 2010 in the pediatric outpatient clinic at Fatih University Hospital were retrieved. Information regarding age, symptoms, history of antibiotic use within 1 month prior to presentation, findings on urinalysis, serum antistreptolysin-O levels, and results of urine/vaginal cultures was collected. The records of 112 patients were evaluated, 72 of which were prepubertal (64.2%) and 40 were pubertal (35.7%) at the time of diagnosis. Thirty-eight prepubertal patients (52.7%) had a positive result on vaginal culture, the most commonly encountered microorganism being group A beta-hemolytic streptococcus (15.2%). Culture positivity rate in the pubertal group was 47.5% (19 patients), with Candida albicans being the most frequently isolated microorganism (27.5%). The etiopathogenesis and culture results differ between prepubertal and adolescent girls with vulvovaginitis, which should be taken into consideration in the treatment approach of this disorder. Copyright © 2012. Published by Elsevier B.V.

  17. Dissipative Effect and Tunneling Time

    Directory of Open Access Journals (Sweden)

    Samyadeb Bhattacharya

    2011-01-01

    Full Text Available The quantum Langevin equation has been studied for dissipative system using the approach of Ford et al. Here, we have considered the inverted harmonic oscillator potential and calculated the effect of dissipation on tunneling time, group delay, and the self-interference term. A critical value of the friction coefficient has been determined for which the self-interference term vanishes. This approach sheds new light on understanding the ion transport at nanoscale.

  18. Diagnostic Markers of Primary Infertility in Women of Reproductive Age with Hypothalamic Dysfunction in the Pubertal Period

    Directory of Open Access Journals (Sweden)

    Irina V. Zhukovets

    2017-09-01

    Full Text Available The aim of the study was to assess fertility in women of reproductive age with hypothalamic dysfunction (HD in the pubertal period and to determine the diagnostic significance of pro-inflammatory (TNF-α and IL-1β, anti-inflammatory cytokine (IL-10 and NF-kB activity in the diagnosis of primary infertility in these women. Materials and Methods: Fertility was assessed in 86 women of reproductive age with HD in the pubertal period. A comparative characteristic of fertile women (Group 1, n=46 and primary infertility women (Group 2, n=21 with HD in the pubertal period was performed. FPG and FPI were determined after 8 to 12 hours of fasting. Serum IRI concentrations were measured using an ELISA kit. The levels of TNF-α, IL-1β and IL-10 were determined in the venous blood serum after a 12-hour fasting, as well as in UA on the 21st day of the menstrual cycle using ELISA kits. The activity of NF-kB was determined in UA on the 21st day of the menstrual cycle using an enzyme immunoassay kit. Results: BMI in Group 1 was significantly lower than in Group 2: 22.63±2.68 kg/m2 versus 27.05±4.03kg/m2 (p=0.000. WC in women of Group 1 was 66.11±5.66cm versus 78.52±10.54cm in Group 2 (p = 0.000; WC >80cm was found in 2(4.4% and 14(66.7% women, respectively (p = 0.000. The average levels of FPG and FPI were significantly higher in Group 2. Serum levels of TNF-α and IL-1β in Group 2 were significantly higher than in Group 1. The serum level of anti-inflammatory cytokine IL-10 was significantly lower in Group 2; accordingly, the TNF-α/IL-10 ratio in Group 2 was 1.8 times higher than in Group 1. The IL-1β level in UA (P=0.000 and the TNF-α/IL-10 ratio (P=0.02 were significantly higher in women of Group 2 than Group 1, which indicated the pronounced inflammatory effects of TNF-α in the endometrium. Imbalance in the production of pro-inflammatory and anti-inflammatory factors indicated the activation of the Th-1 immune response with the formation of the

  19. Treatment timing for an orthopedic approach to patients with increased vertical dimension.

    Science.gov (United States)

    Baccetti, Tiziano; Franchi, Lorenzo; Schulz, Scott O; McNamara, James A

    2008-01-01

    The aim of this study was to investigate the role of treatment timing on the effectiveness of vertical-pull chincup (V-PCC) therapy in conjunction with a bonded rapid maxillary expander (RME) in growing subjects with mild-to-severe hyperdivergent facial patterns. The records of 39 subjects treated with a bonded RME combined with a V-PCC were compared with 29 untreated subjects with similar vertical skeletal disharmonies. Lateral cephalograms were analyzed before (T1) and after treatment or observation (T2). Both the treated and the untreated samples were divided into prepubertal and pubertal groups on the basis of cervical vertebral maturation (prepubertal treated group, 21 subjects; pubertal treated group, 18 subjects; prepubertal control group, 15 subjects; pubertal control group, 14 subjects). Mean change differences from T2 to T1 were compared in the 2 prepubertal and the 2 pubertal groups with independent-sample t tests. No statistically significant differences between the 2 prepubertal groups were found for any cephalometric skeletal measures from T1 to T2. When compared with the untreated pubertal sample, the group treated with the RME and V-PCC at puberty showed a statistically significant reduction in the inclination of the mandibular plane to the Frankfort horizontal (-2.2 mm), a statistically significant reduction in the inclination of the condylar axis to the mandibular plane (-2.2 degrees), and statistically significant supplementary growth of the mandibular ramus (1.7 mm). Treatment of increased vertical dimension with the RME and V-PCC protocol appears to produce better results during the pubertal growth spurt than before puberty, although the absolute amount of correction in the vertical skeletal parameters is limited.

  20. Relationships between anthropometric features, body composition, and anaerobic alactic power in elite post-pubertal and mature male taekwondo athletes

    Directory of Open Access Journals (Sweden)

    Boraczyński Michał

    2017-12-01

    Full Text Available Purpose. The paper describes the relationships between anthropometric features, body composition, and anaerobic alactic power (AAP in elite post-pubertal and mature male taekwondo athletes. Methods. The sample of 41 taekwondo athletes was divided into two groups: post-pubertal (P-P, n = 19, Mage = 15.6 ± 1.1 years and mature (M, n = 22, Mage = 20.7 ± 2.8 years. Anthropometric features (WB-150, ZPU Tryb-Wag, Poland, body composition (BC-418 MA, Tanita, Japan, maturational status (Pubertal Maturational Observational Scale, and AAP (10-s version of the Wingate Anaerobic Test were assessed. Results. Post-hoc testing revealed significant between-group differences (3.2-20.4%, p < 0.01 in all anthropometric and body composition measures, with effect sizes (ES between −0.79 and −1.25 (p < 0.001, except for fat content and percentage of skeletal muscle mass (SMM (p ≥ 0.05. In group M, the maximal power output (Pmax was greater (ES = −1.15, p < 0.001 and the time of its attainment shorter (ES = 0.59, p < 0.001 than in group P-P. Correlation analyses indicated notably strong associations between body mass (BM and Pmax in group P-P (r = 0.950 [95% CI, 0.85-0.98], p < 0.001 and M (r = 0.926 [95% CI, 0.81-0.97], p < 0.001, and similar-sized strong correlations between fat-free mass (FFM and Pmax in group P-P (r = 0.955 [95% CI, 0.86-0.99], p < 0.001 and M (r = 0.924 [95% CI, 0.82-0.96], p < 0.001. Additionally, a strong correlation was found between body height and Pmax in groups P-P and M (r = 0.805 [95% CI, 0.54-0.92], p < 0.001 and r = 0.819 [95% CI, 0.58-0.93], p < 0.001, respectively. Linear regression analyses demonstrated that FFM, BM, and absolute SMM best explained the variance in Pmax in both groups (r, 0.939-0.951; r2, 0.882-0.909. Conclusions. The strong correlations observed in both groups between BM, FFM, SMM, and Pmax demonstrate the significant effects of body size and composition on AAP. By determining the current levels of these

  1. [Pubertal growth of 1,453 healthy children according to age at pubertal growth spurt onset. The Barcelona longitudinal growth study].

    Science.gov (United States)

    Carrascosa, Antonio; Yeste, Diego; Moreno-Galdó, Antonio; Gussinyé, Miquel; Ferrández, Ángel; Clemente, María; Fernández-Cancio, Mónica

    2018-02-20

    Pubertal growth pattern differs according to age at pubertal growth spurt onset which occurs over a five years period (girls: 8-13 years, boys: 10-15 years). The need for more than one pubertal reference pattern has been proposed. We aimed to obtain five 1-year-age-interval pubertal patterns. Longitudinal (6 years of age-adult height) growth study of 1,453 healthy children to evaluate height-for-age, growth velocity-for-age and weight-for-age values. According to age at pubertal growth spurt onset girls were considered: very-early matures (8-9 years, n=119), early matures (9-10 years, n=157), intermediate matures (10-11 years, n=238), late matures (11-12 years, n=127) and very-late matures (12-13 years, n=102), and boys: very-early matures (10-11 years, n=110), early matures (11-12 years, n=139), intermediate matures (12-13 years, n=225), late matures (13-14 years, n=133) and very-late matures (14-15 years, n=103). Age at menarche and growth up to adult height were recorded. In both sexes, statistically-significant (P<.0001) and clinically-pertinent differences in pubertal growth pattern (mean height-for-age, mean growth velocity-for-age and mean pubertal height gain, values) were found among the five pubertal maturity groups and between each group and the whole population, despite similar adult height values. The same occurred for age at menarche and growth from menarche to adult height (P<.05). In both sexes, pubertal growth spurt onset is a critical milestone determining pubertal growth and sexual development. The contribution of our data to better clinical evaluation of growth according to the pubertal maturity tempo of each child will obviate the mistakes made when only one pubertal growth reference is used. Copyright © 2018. Publicado por Elsevier España, S.L.U.

  2. Giant pubertal prolactinoma: Complete resolution following short ...

    African Journals Online (AJOL)

    2016-04-06

    Apr 6, 2016 ... disappeared in a short time with cabergoline treatment. Key words: ... Hyperprolactinemia may cause impotence and hypogonadism in adult men, and rarely ... safe treatment method for male patients with giant prolactinoma.

  3. Learning Time and Educational Effectiveness.

    Science.gov (United States)

    Anderson, Lorin W.

    1980-01-01

    To explore the relationship between time and school learning, this paper defines the three kinds of learning time identified by researchers--allocated time, time-on-task, and academic learning time--and relates them to curriculum development. The author cites evidence that time-on-task is related to student achievement and describes two…

  4. Prenatal androgen excess programs metabolic derangements in pubertal female rats.

    Science.gov (United States)

    Yan, Xiaonan; Dai, Xiaonan; Wang, Jing; Zhao, Nannan; Cui, Yugui; Liu, Jiayin

    2013-04-01

    Owing to the heterogeneity in the clinical symptoms of polycystic ovary syndrome (PCOS), the early pathophysiological mechanisms of PCOS remain unclear. Clinical, experimental, and genetic evidence supports an interaction between genetic susceptibility and the influence of maternal environment in the pathogenesis of PCOS. To determine whether prenatal androgen exposure induced PCOS-related metabolic derangements during pubertal development, we administrated 5α-dihydrotestosterone (DHT) in pregnant rats and observed their female offspring from postnatal 4 to 8 weeks. The prenatally androgenized (PNA) rats exhibited more numerous total follicles, cystic follicles, and atretic follicles than the controls. Fasting glucose, insulin, leptin levels, and homeostatic model assessment for insulin resistance were elevated in the PNA rats at the age of 5-8 weeks. Following intraperitoneal glucose tolerance tests, glucose and insulin levels did not differ between two groups; however, the PNA rats showed significantly higher 30- and 60-min glucose levels than the controls after insulin stimulation during 5-8 weeks. In addition, prenatal DHT treatment significantly decreased insulin-stimulated phosphorylation of AKT in the skeletal muscles of 6-week-old PNA rats. The abundance of IR substrate 1 (IRS1) and IRS2 was decreased in the skeletal muscles and liver after stimulation with insulin in the PNA group, whereas phosphorylation of insulin-signaling proteins was unaltered in the adipose tissue. These findings validate the contribution of prenatal androgen excess to metabolic derangements in pubertal female rats, and the impaired insulin signaling through IRS and AKT may result in the peripheral insulin resistance during pubertal development.

  5. Blood spotting on underpants: Case report of urethral prolapse in a pre-pubertal Chinese girl

    Directory of Open Access Journals (Sweden)

    Hei Yi Wong

    2015-05-01

    Full Text Available Urethral prolapse is a rare urological condition with non-specific clinical manifestations which is mostly seen in pre-pubertal black girls and postmenopausal woman. The exact etiology still remains unknown. We herein present a case report of urethral mucosa prolapse in a 5 year-old Chinese pre-pubertal girl.

  6. Lauric Acid Stimulates Mammary Gland Development of Pubertal Mice through Activation of GPR84 and PI3K/Akt Signaling Pathway.

    Science.gov (United States)

    Meng, Yingying; Zhang, Jing; Zhang, Fenglin; Ai, Wei; Zhu, Xiaotong; Shu, Gang; Wang, Lina; Gao, Ping; Xi, Qianyun; Zhang, Yongliang; Liang, Xingwei; Jiang, Qingyan; Wang, Songbo

    2017-01-11

    It has been demonstrated that dietary fat affects pubertal mammary gland development. However, the role of lauric acid (LA) in this process remains unclear. Thus, this study aimed to investigate the effects of LA on mammary gland development in pubertal mice and to explore the underlying mechanism. In vitro, 100 μM LA significantly promoted proliferation of mouse mammary epithelial cell line HC11 by regulating expression of proliferative markers (cyclin D1/3, p21, PCNA). Meanwhile, LA activated the G protein-coupled receptor 84 (GPR84) and PI3K/Akt signaling pathway. In agreement, dietary 1% LA enhanced mammary duct development, increased the expression of GPR84 and cyclin D1, and activated PI3K/Akt in mammary gland of pubertal mice. Furthermore, knockdown of GPR84 or inhibition of PI3K/Akt totally abolished the promotion of HC11 proliferation induced by LA. These results showed that LA stimulated mammary gland development of pubertal mice through activation of GPR84 and PI3K/Akt signaling pathway.

  7. Gingival crevicular fluid alkaline phosphatase activity in relation to pubertal growth spurt and dental maturation: A multiple regression study

    Directory of Open Access Journals (Sweden)

    Perinetti, G.

    2016-04-01

    Full Text Available Introduction: The identification of the onset of the pubertal growth spurt has major clinical implications when dealing with orthodontic treatment in growing subjects. Aim: Through multivariate methods, this study evaluated possible relationships between the gingival crevicular fluid (GCF alkaline phosphatase (ALP activity and pubertal growth spurt and dentition phase. Materials and methods: One hundred healthy growing subjects (62 females, 38 males; mean age, 11.5±2.4 years were enrolled into this doubleblind, prospective, cross-sectional-design study. Phases of skeletal maturation (pre - pubertal, pubertal, post - pubertal was assessed using the cervical vertebral maturation method. Samples of GCF for the ALP activity determination were collected at the mesial and distal sites of the mandibular central incisors. The phases of the dentition were recorded as intermediate mixed, late mixed, or permanent. A multinomial multiple logistic regression model was used to assess relationships of the enzymatic activity to growth phases and dentition phases. Results: The GCF ALP activity was greater in the pubertal growth phase as compared to the pre - pubertal and post - pubertal growth phases. Significant adjusted odds ratios for the GCF ALP activity for the pre - pubertal and post - pubertal subjects, in relation to the pubertal group, were 0.76 and 0.84, respectively. No significant correlations were seen for the dentition phase. Conclusions: The GCF ALP activity is a valid candidate as a non - invasive biomarker for the identification of the pubertal growth spurt irrespective of the dentition phase.

  8. Granular Vulvovaginitis Syndrome in Nelore pubertal and post pubertal replacement heifers under tropical conditions: role of Mycoplasma spp., Ureaplasma diversum and BHV-1.

    Science.gov (United States)

    Gambarini, M L; Kunz, T L; Oliveira Filho, B D; Porto, R N G; Oliveira, C M G; Brito, W M E D; Viu, M A O

    2009-10-01

    In order to determine the role of Mycoplasma spp, Ureaplasma diversum and BHV-1 as causal agents of Granular Vulvovaginitis Syndrome in Nelore heifers raised under tropical conditions and based on the hypothesis that stressful conditions during puberty or breeding season would be a determinant factor for the infection, 340 heifers not vaccinated against BHV-1 were divided in Post-pubertal, in the beginning of the first breeding season, and Pubertal heifers. The vaginal lesion score (VLS) Grade 1 to 4 was giving according to lesion area and severity. Vaginal mucus was used to isolate Mycoplasma spp., Ureaplasma diversum and BHV-1. The predominant VLS was 2. No sample was positive for BHV-1; 48% were positive for Mycoplasma spp., Ureaplasma diversum, or both, with predominance of Ureaplasma diversum. Serum neutralization for BHV-1 showed more positive animals in pubertal group (23%); 3 of the paired sera demonstrated seroconversion. These data indicated that post-pubertal and pubertal Nelore heifers raised under extensive conditions are more susceptible to Mycoplasma spp. and Ureaplasma diversum. The hypothesis that the stress of pubertal period could lead to an acute vaginal infection by HBV-1 was not proofed.

  9. The Initiation of Dating in Adolescence : The Effect of Parental Divorce. The TRAILS Study

    NARCIS (Netherlands)

    Ivanova, Katya; Mills, Melinda; Veenstra, Rene

    2011-01-01

    This study examined the effect of parental divorce on the time it took adolescents to initiate their first romantic relationships. Individual differences in temperament and pubertal development and the age of the adolescent at the time of divorce were also taken into account. Hypotheses were tested

  10. The Initiation of Dating in Adolescence: The Effect of Parental Divorce. The TRAILS Study

    Science.gov (United States)

    Ivanova, Katya; Mills, Melinda; Veenstra, Rene

    2011-01-01

    This study examined the effect of parental divorce on the time it took adolescents to initiate their first romantic relationships. Individual differences in temperament and pubertal development and the age of the adolescent at the time of divorce were also taken into account. Hypotheses were tested using event history analysis with a sample of…

  11. Pubertal Development and Thyroid Function in Intact Juvenile Rats Exposed to 3-Nitro-1,2,4-Trazol-5-One (NTO), February-June 2012

    Science.gov (United States)

    2014-02-01

    vivo effects on androgen-dependent tissues in young rats (i.e., prochloraz) similar to the effects of NTO in the present study have feminized male...the potential to interact with the endocrine system in vivo by identifying effects on pubertal development and thyroid function in the intact juvenile...estrogen or thyroid active compound under the test conditions. The observed testicular toxicity and the effects on the androgen-dependent reproductive

  12. 7 CFR 953.65 - Effective time.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 953.65 Section 953.65 Agriculture... STATES Order Regulating Handling Effective Time and Termination § 953.65 Effective time. The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature...

  13. 7 CFR 947.70 - Effective time.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 947.70 Section 947.70 Agriculture... Effective Time and Termination § 947.70 Effective time. (a) The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature attached to this subpart, and shall...

  14. 7 CFR 946.62 - Effective time.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 946.62 Section 946.62 Agriculture... Order Regulating Handling Effective Time and Termination § 946.62 Effective time. The provisions of this subpart shall become effective at such time as the Secretary may declare above his signature attached to...

  15. Prenatal androgen excess enhances stimulation of the GNRH pulse in pubertal female rats.

    Science.gov (United States)

    Yan, Xiaonan; Yuan, Chun; Zhao, Nannan; Cui, Yugui; Liu, Jiayin

    2014-07-01

    In adolescent girls with polycystic ovary syndrome (PCOS), neuroendocrine derangements manifest after the onset of puberty, characterized by rapid LH pulse frequency. The early mechanism underlying the pubertal regulation of the GNRH/LH pulsatile release in adolescents with PCOS remains uncertain. To determine the effects of prenatal androgen exposure on the activation of GNRH neurons and generation of LH pulse at puberty, we administrated 5α-dihydrotestosterone to pregnant rats and observed serum LH levels and expression of hypothalamic genes in female offspring from postnatal 4 to 8 weeks. The 6-week-old prenatally androgenized (PNA) female rats exhibited an increase in LH pulse frequency. The hypothalamic expression of neurokinin B (Nkb (Tac2)) and Lepr mRNA levels in PNA rats increased remarkably before puberty and remained high during puberty, whereas elevated Kiss1 mRNA levels were detected only after the onset of puberty. Exogenous kisspeptin, NK3R agonist, and leptin triggered tonic stimulation of GNRH neurons and increased LH secretion in 6-week-old PNA rats. Leptin upregulated Kiss1 mRNA levels in the hypothalamus of pubertal PNA rats; however, pretreatment with a kisspeptin antagonist failed to suppress the elevated serum LH stimulated by leptin, indicating that the stimulatory effects of leptin may be conveyed indirectly to GNRH neurons via other neural components within the GNRH neuronal network, rather than through the kisspeptin-GPR54 pathway. These findings validate the hypotheses that NKB and leptin play an essential role in the activation of GNRH neurons and initiation of increased LH pulse frequency in PNA female rats at puberty and that kisspeptin may coordinate their stimulatory effects on LH release. © 2014 Society for Endocrinology.

  16. An Unexpected Cause of Pelvic Pain in a Pubertal Case: Herlyn-Werner-Wunderlich Syndrome

    Directory of Open Access Journals (Sweden)

    Yasemin Kayadibi

    2014-03-01

    Full Text Available Uterovaginal duplication with imperforated hemivagina is a rare type of Mullerian anomaly. If ipsilateral renal agenesis is associated with this complex genital malformation, it is called Herlyn-Werner-Wunderlich syndrome. Clinical presentations of this syndrome include pelvic pain and mass effect due to obstructed hemivagina in pubertal adolescents and adults. Hematocolpos, even after menstruation period, leads to misdiagnosis. Laparotomy is the gold standard for the diagnosis, however, magnetic resonance imaging has an accuracy upto 100% in evaluating uterovajinal anatomy. In this article, we aimed to present ultrasonographic and magnetic resonance imaging findings in a patient with Herlyn-Werner-Wun derlich syndrome who presented with cyclic pelvic pain. (The Me­di­cal Bul­le­tin of Ha­se­ki 2014; 52: 60-3

  17. Improving productivity through more effective time management.

    Science.gov (United States)

    Arnold, Edwin; Pulich, Marcia

    2004-01-01

    Effective time management has become increasingly important for managers as they seek to accomplish objectives in today's organizations, which have been restructured for efficiency while employing fewer people. Managers can improve their ability to manage time effectively by examining their attitudes toward time, analyzing time-wasting behaviors, and developing better time management skills. Managers can improve their performance and promotion potential with more effective time utilization. Strategies for improving time management skills are presented.

  18. Hormonal, anthropometric and lipid factors associated with idiopathic pubertal gynecomastia.

    Science.gov (United States)

    Al Alwan, Ibrahim; Al Azkawi, Hanan; Badri, Motasim; Tamim, Hani; Al Dubayee, Mohammed; Tamimi, Waleed

    2013-01-01

    To determine factors associated with pubertal gynecomastia. A cross-sectional study among healthy male school children and adolescents in Riyadh, Saudi Arabia. Subjects were selected from diverse socioeconomic backgrounds. Tanner stage, height, weight, blood hormonal levels (leutilizing hormone [LH], follicle-stimulating hormone [FSH], total testosterone, and estradiol), and anthropometric and lipid parameters (body mass index [BMI], triglycerides, high-density lipoprotein [HDL], and low-density lipoprotein [LDL]), were collected and compared in children with and without gynecomastia. The study included 542 children and adolescents. Median (interquartile range) age in the whole group was 11(8-13) years. The prevalence of gynecomastia was 185/542 (34%), with a peak at age 14. The 2 groups compared had nonsignificant difference in cholesterol (P=.331), LH (P=.215) and FSH (P=.571) levels. Those with gynecomastia were significantly older, had lower gonad stage, had higher anthropometric (height, weight, and BMI), and lipid (triglycerides, HDL, and LDL) values. In multivariate regression analysis, factors significantly associated with gynecomastia were BMI (odds ratio [OR]=1.05; 95%CI 1.00-1.10; P=.013), HDL (OR=0.42; 95%CI 0.19-0.92; P=.03), and gonad (Stage II OR=2.23; 95%CI 1.27-3.92; P=.005, Stage III OR=6.40; 95%CI 2.70-15.0; P gynecomastia tends to increase in mid-puberty. In our setting, BMI, HDL, and gonad stage were the major factors associated with the development of pubertal gynecomastia.

  19. Timing effects in health valuations.

    Science.gov (United States)

    Leiter, Andrea M; Pruckner, Gerald J

    2014-06-01

    This paper analyzes the impact of external sources of information, conveyed by the frequency of risky events that vary across time, on the individual willingness to pay (WTP) for a reduction of mortality risk. We collected data from a contingent valuation (CV) exercise conducted in two waves (fall and winter) to examine whether individual WTP varied across periods that differed in the predominance of fatal accidents. Risk valuations were based on fatal snow avalanche accidents, that is, a type of risk with seasonal differences in occurrence. We found slightly lower but statistically significant mean WTP figures in the winter than in the fall sample because of time-varying individual risk attitudes and, therefore, recommend controlling for these factors in risk assessment CV surveys. Copyright © 2013 John Wiley & Sons, Ltd.

  20. 7 CFR 927.77 - Effective time.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 927.77 Section 927.77 Agriculture... Order Regulating Handling Miscellaneous Provisions § 927.77 Effective time. The provisions of this subpart and of any amendment thereto shall become effective at such time as the Secretary may declare, and...

  1. 7 CFR 922.63 - Effective time.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 922.63 Section 922.63 Agriculture... IN WASHINGTON Order Regulating Handling Miscellaneous Provisions § 922.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary...

  2. 7 CFR 924.63 - Effective time.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 924.63 Section 924.63 Agriculture... § 924.63 Effective time. The provisions of this part and any amendments thereto shall become effective at such time as the Secretary may declare above his signature, and shall continue in force until...

  3. 7 CFR 959.83 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 959.83 Section 959.83 Agriculture... Regulating Handling Miscellaneous Provisions § 959.83 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in...

  4. 7 CFR 985.71 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 985.71 Section 985.71 Agriculture....71 Effective time. The provisions of this subpart, and of any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in force until terminated or...

  5. 7 CFR 958.70 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 958.70 Section 958.70 Agriculture... COUNTIES IN IDAHO, AND MALHEUR COUNTY, OREGON Order Regulating Handling Effective Time and Termination § 958.70 Effective time. The provisions of this subpart, or any amendment thereto, shall become...

  6. 7 CFR 932.67 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 932.67 Section 932.67 Agriculture... Regulating Handling Miscellaneous Provisions § 932.67 Effective time. The provisions of this subpart, as well as any amendments to this subpart, shall become effective at such time as the Secretary may declare...

  7. 7 CFR 989.90 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 989.90 Section 989.90 Agriculture... CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 989.90 Effective time. The provisions of this amended subpart, as well as any amendments to this amended subpart shall become effective at such time as...

  8. 7 CFR 906.54 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 906.54 Section 906.54 Agriculture... RIO GRANDE VALLEY IN TEXAS Order Regulating Handling Miscellaneous Provisions § 906.54 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the...

  9. 7 CFR 915.63 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 915.63 Section 915.63 Agriculture... Regulating Handling Miscellaneous Provisions § 915.63 Effective time. The provisions of this part shall become effective at such time as the Secretary may declare above his signature to this part, and shall...

  10. 7 CFR 929.68 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 929.68 Section 929.68 Agriculture... Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare above his signature and shall continue in force until terminated in...

  11. 7 CFR 983.87 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 983.87 Section 983.87 Agriculture..., ARIZONA, AND NEW MEXICO Miscellaneous Provisions § 983.87 Effective time. The provisions of this part, as well as any amendments, shall become effective at such time as the Secretary may declare, and shall...

  12. 7 CFR 917.60 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 917.60 Section 917.60 Agriculture... CALIFORNIA Order Regulating Handling Miscellaneous Provisions § 917.60 Effective time. The provisions of this part and of any amendment thereto, shall become effective at such time as the Secretary may declare...

  13. 7 CFR 948.83 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 948.83 Section 948.83 Agriculture... Order Regulating Handling Miscellaneous Provisions § 948.83 Effective time. The provisions of this subpart or any amendments thereto shall become effective at such time as the Secretary may declare and...

  14. 7 CFR 993.89 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 993.89 Section 993.89 Agriculture... Order Regulating Handling Miscellaneous Provisions § 993.89 Effective time. The provisions of this subpart, as well as any amendments to this subpart, shall become effective at such time as the Secretary...

  15. 7 CFR 916.63 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 916.63 Section 916.63 Agriculture... Regulating Handling Miscellaneous Provisions § 916.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare above his signature and...

  16. 7 CFR 923.63 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 923.63 Section 923.63 Agriculture... COUNTIES IN WASHINGTON Order Regulating Handling Miscellaneous Provisions § 923.63 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary...

  17. 7 CFR 945.82 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 945.82 Section 945.82 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... § 945.82 Effective time. The provisions of this subpart shall become effective at such time as the...

  18. 7 CFR 966.83 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 966.83 Section 966.83 Agriculture... Regulating Handling Miscellaneous Provisions § 966.83 Effective time. The provisions of this subpart, or any amendment thereto, shall become effective at such time as the Secretary may declare and shall continue in...

  19. 7 CFR 930.82 - Effective time.

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    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 930.82 Section 930.82 Agriculture... Miscellaneous Provisions § 930.82 Effective time. The provisions of this part, and of any amendment thereto, shall become effective at such time as the Secretary may declare, and shall continue in force until...

  20. Insulin resistance in obese pre-pubertal children: Relation to body ...

    African Journals Online (AJOL)

    Secondary outcome is to determine the frequency of the metabolic syndrome components. Subjects and methods: Twenty-three pre-pubertal obese children were ... oral glucose tolerance testing (OGTT) and DXA scan for body composition.

  1. Brief communication: a proposed osteological method for the estimation of pubertal stage in human skeletal remains.

    Science.gov (United States)

    Shapland, Fiona; Lewis, Mary E

    2013-06-01

    Puberty forms an important threshold between childhood and adulthood, but this subject has received little attention in bioarchaeology. The new application of clinical methods to assess pubertal stage in adolescent skeletal remains is explored, concentrating on the development of the mandibular canine, hamate, hand phalanges, iliac crest and distal radius. Initial results from the medieval cemetery of St. Peter's Church, Barton-upon-Humber, England suggest that application of these methods may provide insights into aspects of adolescent development. This analysis indicates that adolescents from this medieval site were entering the pubertal growth spurt at a similar age to their modern counterparts, but that the later stages of pubertal maturation were being significantly delayed, perhaps due to environmental stress. Continued testing and refinement of these methods on living adolescents is still necessary to improve our understanding of their significance and accuracy in predicting pubertal stages. Copyright © 2013 Wiley Periodicals, Inc.

  2. A pre-pubertal girl with giant juvenile fibroadenoma: A rare case report

    Directory of Open Access Journals (Sweden)

    Kumar Gaurav

    2015-01-01

    Conclusion: Through this case we want to emphasize that these giant benign neoplasms should be suspected in any pre-pubertal girl with breast lump and should always be treated with breast conserving surgery.

  3. Pubertal testosterone influences threat-related amygdala-orbitofrontal cortex coupling.

    Science.gov (United States)

    Spielberg, Jeffrey M; Forbes, Erika E; Ladouceur, Cecile D; Worthman, Carol M; Olino, Thomas M; Ryan, Neal D; Dahl, Ronald E

    2015-03-01

    Growing evidence indicates that normative pubertal maturation is associated with increased threat reactivity, and this developmental shift has been implicated in the increased rates of adolescent affective disorders. However, the neural mechanisms involved in this pubertal increase in threat reactivity remain unknown. Research in adults indicates that testosterone transiently decreases amygdala-orbitofrontal cortex (OFC) coupling. Consequently, we hypothesized that increased pubertal testosterone disrupts amygdala-OFC coupling, which may contribute to developmental increases in threat reactivity in some adolescents. Hypotheses were tested in a longitudinal study by examining the impact of testosterone on functional connectivity. Findings were consistent with hypotheses and advance our understanding of normative pubertal changes in neural systems instantiating affect/motivation. Finally, potential novel insights into the neurodevelopmental pathways that may contribute to adolescent vulnerability to behavioral and emotional problems are discussed. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  4. Duration of the pubertal peak in skeletal Class I and Class III subjects.

    Science.gov (United States)

    Kuc-Michalska, Małgorzata; Baccetti, Tiziano

    2010-01-01

    To estimate and compare the duration of the pubertal growth peak in Class I and Class III subjects. The data examined consisted of pretreatment lateral cephalometric records of 218 skeletal Class I or Class III subjects (93 female and 125 male subjects) of white ancestry. The duration of the pubertal peak was calculated from the average chronological age intervals between stages CS3 and CS4 of the cervical vertebral maturation in Class I vs Class III groups (t-test). In skeletal Class I subjects, the pubertal peak had a mean duration of 11 months, whereas in Class III subjects it lasted 16 months. The average difference (5 months) was statistically significant (P < .001). The growth interval corresponding to the pubertal growth spurt (CS3-CS4) was longer in Class III subjects than in subjects with normal skeletal relationships; the larger increases in mandibular length during the pubertal peak reported in the literature for Class III subjects may be related to the longer duration of the pubertal peak.

  5. Sulforaphane attenuates di-N-butylphthalate-induced reproductive damage in pubertal mice: Involvement of the Nrf2-antioxidant system.

    Science.gov (United States)

    Jiang, Xu-Ping; Tang, Jing-Yuan; Xu, Zhen; Han, Peng; Qin, Zhi-Qiang; Yang, Cheng-di; Wang, Shang-Qian; Tang, Min; Wang, Wei; Qin, Chao; Xu, Yang; Shen, Bai-Xin; Zhou, Wei-Min; Zhang, Wei

    2017-07-01

    di-N-butylphthalate (DBP) is a ubiquitous environmental pollutant used for plastic coating and in the cosmetics industry. It has toxic effects on body health, especially the male reproductive system. Here, we investigated the effects of DBP on the male reproductive system of pubertal mice and explored the protective role of sulforaphane (SFN). The results showed that DBP significantly reduced the anogenital distance, testicular weight, sperm count and motility, and plasma and testicular testosterone levels and significantly increased the oxidative stress, sperm abnormalities, and testicular cell apoptosis. SFN supplementation ameliorated these effects. After DBP stimulation, the transcription factor nuclear factor erythroid-related factor 2 (Nrf2) was adaptively increased together with its target genes, such as HO-1 and NQO1. Upregulation of Nrf2 by SFN reduced the DBP-mediated intracellular oxidative toxicity and also increased testosterone secretion and spermatogenesis, which were decreased by DBP. These findings indicate that SFN can attenuate DBP-induced reproductive damage in pubertal mice via Nrf2-associated pathways. © 2017 Wiley Periodicals, Inc.

  6. Effective time management – selected issues

    Directory of Open Access Journals (Sweden)

    Aneta Olejniczak

    2013-03-01

    Full Text Available Deliberations included in this article contain the basic issues related to the subject of time management. As we know, people who waste their time the most, most complain about the lack of the time. We should treat our time, time of our co-workers, and friends as a valuable, but limited wealth. Principles of effective time management can be applied in any scientific and research institutions, companies or corporations. The benefits of a good and effective time management will be felt not only by ourselves but also by our friends and family. Detailed formulation of objectives, identification and elimination of time wasters and postponing work on later (Procrastination, using methods of time management and systematic control will allow for efficient use of time. A good plan is the basis for optimal and meaningful use of time.

  7. Relationships between urinary biomarkers of phytoestrogens, phthalates, phenols, and pubertal stages in girls

    Directory of Open Access Journals (Sweden)

    Chakraborty TR

    2012-01-01

    Full Text Available Tandra R Chakraborty1, Eilliut Alicea1, Sanjoy Chakraborty21Department of Biology, Adelphi University, One South Avenue, Garden City; 2Department of Biological Sciences, New York City College of Technology, New York, NY, USAAbstract: Phytoestrogens, phthalates, and phenols are estrogen-disrupting chemicals that have a pronounced effect at puberty. They are exogenous chemicals that are either plant-derived or man-made, and can alter the functions of the endocrine system and cause various health defects by interfering with the synthesis, metabolism, binding, or cellular responses of natural estrogens. Phytoestrogens, phthalates, and phenols are some of the potent estrogens detectable in urine. Phytoestrogens are plant-derived xenestrogens found in a wide variety of food products, like soy-based food, beverages, several fruits, and vegetables. Exposure to phytoestrogens can delay breast development and further lead to precocious puberty. The effect of phytoestrogens is mediated through estrogen receptors α and β or by binding with early immediate genes, such as jun and fos. Phthalates are multifunctional synthetic chemicals used in plastics, polyvinyl chloride products, cosmetics, hair spray, and children's toys. Phthalates have been shown to cause defeminization, thelarche, precocious puberty, and an increase in breast and pubic hair in pubertal girls. However, reports are also available that show no association of phthalates with precocious puberty in girls. Phthalates can act through a receptor-mediated signaling pathway or affect the production of luteinizing hormone and follicle-stimulating hormone that has a direct effect on estrogen formation. Phenols like bisphenol A are industrial chemicals used mainly in the manufacture of polycarbonates and plastic materials. Bisphenol A has been shown to cause precocious puberty and earlier menarche in pubertal girls. Reports suggest that the neurotoxic effect of bisphenol A can be mediated either by

  8. Effective Feature Preprocessing for Time Series Forecasting

    DEFF Research Database (Denmark)

    Zhao, Junhua; Dong, Zhaoyang; Xu, Zhao

    2006-01-01

    Time series forecasting is an important area in data mining research. Feature preprocessing techniques have significant influence on forecasting accuracy, therefore are essential in a forecasting model. Although several feature preprocessing techniques have been applied in time series forecasting...... performance in time series forecasting. It is demonstrated in our experiment that, effective feature preprocessing can significantly enhance forecasting accuracy. This research can be a useful guidance for researchers on effectively selecting feature preprocessing techniques and integrating them with time...... series forecasting models....

  9. Examination of US puberty-timing data from 1940 to 1994 for secular trends

    DEFF Research Database (Denmark)

    Euling, Susan Y; Herman-Giddens, Marcia E; Lee, Peter A

    2008-01-01

    or girls. A majority of the panelists agreed that data are sufficient to suggest a trend toward an earlier breast development onset and menarche in girls but not for other female pubertal markers. A minority of panelists concluded that the current data on girls' puberty timing for any marker...... are insufficient. Almost all panelists concluded, on the basis of few studies and reliability issues of some male puberty markers, that current data for boys are insufficient to evaluate secular trends in male pubertal development. The panel agreed that altered puberty timing should be considered an adverse effect......Whether children, especially girls, are entering and progressing through puberty earlier today than in the mid-1900s has been debated. Secular trend analysis, based on available data, is limited by data comparability among studies in different populations, in different periods of time, and using...

  10. Attachment, parenting styles and bullying during pubertal years.

    Science.gov (United States)

    van der Watt, Ronél

    2014-01-01

    Research that focuses on combining attachment, parenting styles, bullying and the reciprocal nature thereof in the parent-adolescent and peer relationships is limited. The bio-psychosocial changes that adolescents experience open up broader social realities and are perceived differently by parents and adolescents. Attachment processes and parenting styles may elicit dissimilar perceptions. These processes are also associated with the multifaceted dynamics of bullying. The aim of the article is to advocate for research on the possible link between the implications of attachment, parenting styles and bullying. Exploring the association between attachment, parenting styles and bullying can deepen the understanding of the developmental challenges within the parent-adolescent relationship, add insight to the different perceptions of adolescents and parents, and complement intervention programmes accordingly. Firstly, this article outlines bio-psychosocial changes in the pubertal years as related to the social realities of the adolescent. Secondly, a discussion on the concepts 'attachment', 'parenting styles', 'bullying', and the potential link between these concepts will follow. Thirdly, an outline of the clinical implications of the apparent association between these concepts is given. The article concludes with recommendations that researchers can consider while exploring the relationship between attachment, parenting styles, and bullying and the delineation thereof in the parent-adolescent relationship.

  11. Cardiovascular risk factors in pre-pubertal schoolchildren in Angola.

    Science.gov (United States)

    Silva, Amílcar B; Capingana, Daniel P; Magalhães, Pedro; Gonçalves, Mauer A; Molina, Maria Del Carmen B; Rodrigues, Sërgio L; Baldo, Marcelo P; Mateus, Miguel S; Mill, Josë Geraldo

    The incidence of obesity is increasing worldwide, especially in countries with accelerated economic growth. We determined the prevalence of and associations between overweight/obesity and cardiovascular risk factors in pre-pubertal (seven- to 11-year-old) schoolchildren (both genders, n = 198) in Luanda, Angola. Biochemical (fasting blood) and clinical examinations were obtained in a single visit. Data are reported as prevalence (95% confidence intervals) and association (r, Pearson). Prevalence of overweight/obesity was 17.7% (12.4- 23.0%), high blood pressure (BP > 90% percentile) was 14.6% (9.7-19.5%), elevated glucose level was 16.7% (11.5-21.9%) and total cholesterol level > 170 mg/dl (4.4 mmol/l) was 69.2% (62.8-75.6%). Significant associations between body mass index (BMI) and systolic and diastolic BP (r = 0.46 and 0.40, respectively; p Angola and fat accumulation was directly associated with blood pressure increase but not with other cardiovascular risk factors.

  12. Maternal swimming exercise during pregnancy attenuates anxiety/depressive-like behaviors and voluntary morphine consumption in the pubertal male and female rat offspring born from morphine dependent mothers.

    Science.gov (United States)

    Torabi, Masoumeh; Pooriamehr, Alireza; Bigdeli, Imanollah; Miladi-Gorji, Hossein

    2017-10-17

    This study was designed to examine whether maternal swimming exercise during pregnancy would attenuate prenatally morphine-induced anxiety, depression and voluntary consumption of morphine in the pubertal male and female rat offspring. Pregnant rats during the development of morphine dependence were allowed to swim (30-45min/d, 3days per a week) on gestational days 11-18. Then, the pubertal male and female rat offspring were tested for the elevated plus-maze (EPM), sucrose preference test (SPT) and voluntary morphine consumption using a two-bottle choice (TBC) paradigm. The results showed that male and female rat offspring born of the swimmer morphine-dependent mothers exhibited an increase in EPM open arm time and entries, higher levels of sucrose preference than their sedentary control mothers. Voluntary consumption of morphine was less in the male and female rat offspring born of the swimmer morphine-dependent mothers as compared with their sedentary control mothers during three periods of the intake of drug. Thus, swimming exercise in pregnant morphine dependent mothers decreased anxiety, depressive-like behavior and also the voluntary morphine consumption in the pubertal male and female offspring, which may prevent prenatally morphine-induced behavioral sensitization in offspring. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. 7 CFR 996.75 - Effective time.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 996.75 Section 996.75 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Effective time. The provisions of this part, as well as any amendments, shall apply to 2003-04 and...

  14. 7 CFR 905.82 - Effective time.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Effective time. 905.82 Section 905.82 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... TANGELOS GROWN IN FLORIDA Order Regulating Handling Miscellaneous Provisions § 905.82 Effective time. The...

  15. Pubertal development in children diagnosed with diabetes mellitus type 1 before puberty.

    Science.gov (United States)

    Pereira, K C X; Pugliese, B S; Guimarães, M M; Gama, M P

    2015-02-01

    To investigate an association between pubertal development and timing of menarche with glycemic control, disease duration, and body mass index (BMI) in patients diagnosed with diabetes mellitus type 1 (DM1) before puberty. Retrospective study. The study was performed at the diabetes outpatient clinic of Instituto de Puericultura e Pediatria Martagão Gesteira--IPPMG of the Federal University of Rio de Janeiro--UFRJ. A total of 131 children, 61 girls and 70 boys, diagnosed with DM1 before puberty participated in the study. The study investigated how age at puberty onset relates to mean glycated hemoglobin (HbA1c) before puberty, BMI percentile, and disease duration; how puberty duration relates to mean HbA1c before and during puberty and to disease duration; and how timing of menarche relates to mean HbA1c before puberty, BMI percentile, and disease duration. Age at puberty onset was positively correlated with mean HbA1c before puberty (r = 0.204, R(2) = 0.042; P = .019) and disease duration (r = 0.451, R(2) = 0.203; P puberty later than those diagnosed more recently. Girls in higher BMI percentiles reached menarche sooner.

  16. IGF-1 has sexually dimorphic, pleiotropic, and time-dependent effects on healthspan, pathology, and lifespan.

    Science.gov (United States)

    Ashpole, Nicole M; Logan, Sreemathi; Yabluchanskiy, Andriy; Mitschelen, Matthew C; Yan, Han; Farley, Julie A; Hodges, Erik L; Ungvari, Zoltan; Csiszar, Anna; Chen, Sixia; Georgescu, Constantin; Hubbard, Gene B; Ikeno, Yuji; Sonntag, William E

    2017-04-01

    Reduced circulating levels of IGF-1 have been proposed as a conserved anti-aging mechanism that contributes to increased lifespan in diverse experimental models. However, IGF-1 has also been shown to be essential for normal development and the maintenance of tissue function late into the lifespan. These disparate findings suggest that IGF-1 may be a pleiotropic modulator of health and aging, as reductions in IGF-1 may be beneficial for one aspect of aging, but detrimental for another. We postulated that the effects of IGF-1 on tissue health and function in advanced age are dependent on the tissue, the sex of the animal, and the age at which IGF-1 is manipulated. In this study, we examined how alterations in IGF-1 levels at multiple stages of development and aging influence overall lifespan, healthspan, and pathology. Specifically, we investigated the effects of perinatal, post-pubertal, and late-adult onset IGF-1 deficiency using genetic and viral approaches in both male and female igf f/f C57Bl/6 mice. Our results support the concept that IGF-1 levels early during lifespan establish the conditions necessary for subsequent healthspan and pathological changes that contribute to aging. Nevertheless, these changes are specific for each sex and tissue. Importantly, late-life IGF-1 deficiency (a time point relevant for human studies) reduces cancer risk but does not increase lifespan. Overall, our results indicate that the levels of IGF-1 during development influence late-life pathology, suggesting that IGF-1 is a developmental driver of healthspan, pathology, and lifespan.

  17. Effect of time on dyeing wastewater treatment

    Science.gov (United States)

    Ye, Tingjin; Chen, Xin; Xu, Zizhen; Chen, Xiaogang; Shi, Liang; He, Lingfeng; Zhang, Yongli

    2018-03-01

    The preparation of carboxymethylchitosan wrapping fly-ash adsorbent using high temperature activated fly ash and sodium carboxymethyl chitosan (CWF), as with the iron-carbon micro-electrolysis process simulation and actual printing and dyeing wastewater. The effects of mixing time and static time on decolorization ratio, COD removing rate and turbidness removing rate were investigated. The experimental results show that the wastewater stirring times on the decolorization rate and COD removal rate and turbidity removal rate influence, with increasing of the stirring time, three showed a downward trend, and reached the peak at 10 min time; wastewater time on the decolorization ratio and COD removing efficiency and turbidness removing rate influence, along with standing time increase, three who declined and reached the maximum in 30min time.

  18. TIME MANAGEMENT: AN IMPERATIVE FACTOR TO EFFECTIVE ...

    African Journals Online (AJOL)

    CIU

    Nigeria public servants are faced with time management problems which have become a hindrance to effective ... textbooks and internet sources. Statistical data .... accountable for their actions and to make decisions in reference to the use of.

  19. Serum AMH levels are lower in healthy boys who develop pubertal gynaecomastia

    DEFF Research Database (Denmark)

    Mieritz, Mikkel G.; Hagen, Casper P.; Almstrup, Kristian

    2015-01-01

    Background: Pubertal gynaecomastia is thought to be a clinical sign of an oestrogen-androgen imbalance, affecting up to 60% of boys. In most cases no underlying endocrinopathy can be identified. In boys, Anti-mullerian hormone (AMH) is produced by immature Sertoli cells and circulating level...... decreases as testosterone increases during pubertal maturation. In a previous cross sectional study we found significant lower levels of AMH in boys with pubertal gynaecomastia (Mieritz et al., Clin Endocrinol, 2013). Objective and hypotheses: To investigate serum AMH levels and genetic polymorphisms...... in boys with or without gynaecomastia. Method: 99 healthy Danish boys (aged 5.8-16.4 years) were followed in a prospective cohort over 8 years with semi-annual examinations (total examinations, n=951), including breast palpations and blood samples. Serum AMH concentrations were analysed by immunoassay...

  20. Elevated serum IGF-I, but unaltered sex steroid levels, in healthy boys with pubertal gynaecomastia

    DEFF Research Database (Denmark)

    Mieritz, Mikkel G; Sorensen, Kaspar; Aksglaede, Lise

    2014-01-01

    OBJECTIVE: Pubertal gynaecomastia is a very common condition. Although the underlying aetiology is poorly understood, it is generally accepted that excess of oestrogens and deficit of androgens are involved in the pathogenesis. Furthermore, adiposity as well as the GH/IGF-I axis may play a role....... In this study, we elucidate the association of adiposity and levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), sex hormone-binding globulin (SHBG), testosterone, oestrogen, IGF-I and IGFBP-3 with the presence of pubertal gynaecomastia in a large cohort of healthy boys. PATIENTS: A total...... of 501 healthy Danish school boys (aged 6·1-19·8 year) from the COPENHAGEN Puberty Study. MEASUREMENTS: Anthropometry and pubertal stages (PH1-6 and G1-5) were evaluated, and the presence of gynaecomastia was assessed. Body fat percentage was calculated by means of four skin folds and impedance...

  1. Impact of Pubertal Development and Physical Activity on Heart Rate Variability in Overweight and Obese Children in Taiwan

    Science.gov (United States)

    Chen, Su-Ru; Chiu, Hung-Wen; Lee, Yann-Jinn; Sheen, Tzong-Chi; Jeng, Chii

    2012-01-01

    Child obesity is frequently associated with dysfunction of autonomic nervous system. Children in pubertal development were suggested to be vulnerable to autonomic nervous system problems such as decrease of heart rate variability from dysregulation of metabolic control. This study explored the influence of pubertal development on autonomic nervous…

  2. A Short-Term Longitudinal Study of Pubertal Change, Gender, and Psychological Well-Being of Mexican Early Adolescents.

    Science.gov (United States)

    Benjet, Corina; Hernandez-Guzman, Laura

    2002-01-01

    Studied the role of pubertal development on depression, externalizing behavior problems, self-esteem, and body-image of 951 Mexican early adolescents. Findings show that the acute experience of menarche adversely affected the psychological well-being of girls, specifically in terms of depressive symptomatology. Pubertal change in boys did not…

  3. The Interplay between Gaze Following, Emotion Recognition, and Empathy across Adolescence; a Pubertal Dip in Performance?

    Directory of Open Access Journals (Sweden)

    Rianne van Rooijen

    2018-02-01

    Full Text Available During puberty a dip in face recognition is often observed, possibly caused by heightened levels of gonadal hormones which in turn affects the re-organization of relevant cortical circuitry. In the current study we investigated whether a pubertal dip could be observed in three other abilities related to social information processing: gaze following, emotion recognition from the eyes, and empathizing abilities. Across these abilities we further explored whether these measurements revealed sex differences as another way to understand how gonadal hormones affect processing of social information. Results show that across adolescence, there are improvements in emotion recognition from the eyes and in empathizing abilities. These improvements did not show a dip, but are more plateau-like. The gaze cueing effect did not change over adolescence. We only observed sex differences in empathizing abilities, with girls showing higher scores than boys. Based on these results it appears that gonadal hormones are not exerting a unified influence on higher levels of social information processing. Further research should also explore changes in (visual information processing around puberty onset to find a more fitted explanation for changes in social behavior across adolescence.

  4. Puberty: Maturation, Timing and Adjustment, and Sexual Identity Developmental Milestones among Lesbian, Gay, and Bisexual Youth

    Science.gov (United States)

    Grossman, Arnold H.; Foss, Alexander H.; D'Augelli, Anthony R.

    2014-01-01

    This study examined pubertal maturation, pubertal timing and outcomes, and the relationship of puberty and sexual identity developmental milestones among 507 lesbian, gay, and bisexual youth. The onset of menarche and spermarche occurred at the mean ages of 12.05 and 12.46, respectively. There was no statistically significant difference in…

  5. Pubertal stage and the prevalence of violence and social/relational aggression.

    Science.gov (United States)

    Hemphill, Sheryl A; Kotevski, Aneta; Herrenkohl, Todd I; Toumbourou, John W; Carlin, John B; Catalano, Richard F; Patton, George C

    2010-08-01

    We examined associations between pubertal stage and violent adolescent behavior and social/relational aggression. The International Youth Development Study comprises statewide representative student samples in grades 5, 7, and 9 (N = 5769) in Washington State and Victoria, Australia, drawn as a 2-stage cluster sample in each state. We used a school-administered, self-report student survey to measure previous-year violent behavior (ie, attacking or beating up another person) and social/relational aggression (excluding peers from the group, threatening to spread lies or rumors), as well as risk and protective factors and pubertal development. Cross-sectional data were analyzed. Compared with early puberty, the odds of violent behavior were approximately threefold higher in midpuberty (odds ratio [OR]: 2.87 [95% confidence interval (CI): 1.81-4.55]) and late puberty (OR: 3.79 [95% CI: 2.25-6.39]) after adjustment for demographic factors. For social/relational aggression, there were weaker overall associations after adjustment, but these associations included an interaction between pubertal stage and age, and stronger associations with pubertal stage at younger age were shown (P = .003; midpuberty OR: 1.78 [95% CI: 1.20-2.63]; late puberty OR: 3.00 [95% CI: 1.95-4.63]). Associations between pubertal stage and violent behavior and social/relational aggression remained after the inclusion of social contextual mediators in the analyses. Pubertal stage was associated with higher rates of violent behavior and social/relational aggression, with the latter association seen only at younger ages. Puberty is an important phase at which to implement prevention programs to reduce adolescent violent and antisocial behaviors.

  6. Endothelial function in pre-pubertal children at risk of developing cardiomyopathy: a new frontier

    Directory of Open Access Journals (Sweden)

    Aline Cristina Tavares

    2012-01-01

    Full Text Available Although it is known that obesity, diabetes, and Kawasaki's disease play important roles in systemic inflammation and in the development of both endothelial dysfunction and cardiomyopathy, there is a lack of data regarding the endothelial function of pre-pubertal children suffering from cardiomyopathy. In this study, we performed a systematic review of the literature on pre-pubertal children at risk of developing cardiomyopathy to assess the endothelial function of pre-pubertal children at risk of developing cardiomyopathy. We searched the published literature indexed in PubMed, Bireme and SciELO using the keywords 'endothelial', 'children', 'pediatric' and 'infant' and then compiled a systematic review. The end points were age, the pubertal stage, sex differences, the method used for the endothelial evaluation and the endothelial values themselves. No studies on children with cardiomyopathy were found. Only 11 papers were selected for our complete analysis, where these included reports on the flow-mediated percentage dilatation, the values of which were 9.80±1.80, 5.90±1.29, 4.50±0.70, and 7.10±1.27 for healthy, obese, diabetic and pre-pubertal children with Kawasaki's disease, respectively. There was no significant difference in the dilatation, independent of the endothelium, either among the groups or between the genders for both of the measurements in children; similar results have been found in adolescents and adults. The endothelial function in cardiomyopathic children remains unclear because of the lack of data; nevertheless, the known dysfunctions in children with obesity, type 1 diabetes and Kawasaki's disease may influence the severity of the cardiovascular symptoms, the prognosis, and the mortality rate. The results of this study encourage future research into the consequences of endothelial dysfunction in pre-pubertal children.

  7. Trends in puberty timing in humans and environmental modifiers

    DEFF Research Database (Denmark)

    Toppari, Jorma; Juul, Anders

    2010-01-01

    Secular trends in timing of puberty appear to continue although under-nutrition has not been any longer a limiting factor for pubertal development. Now obesity and other environmental reasons have been suspected to cause this trend, and endocrine disrupting chemicals have become into focus...... as possible contributors. Epidemiological studies on endocrine disrupters are still scarce and show only weak associations between exposures and timing of puberty. Since genetic background explains 50-80% of variability in the timing of puberty, it is not surprising that the observed environmental effects...

  8. The effects of out-of-school time on changes in youth risk of obesity across the adolescent years.

    Science.gov (United States)

    Zarrett, Nicole; Bell, Bethany A

    2014-01-01

    This study examined the longitudinal effects of out-of-school time (OST) activities on youth weight-status through mid-to-late adolescence. First, using pattern-centered methods, we identified the prominent ways in which youth allocate their OST across 12 common active and sedentary activities available to them. Second, through multi-level modeling procedures we examined the relation of OST activity patterns to: 1) BMI-status during the 11th grade, and; 2) within-person change in BMI-status across the adolescent years. After accounting for race, gender, SES, pubertal-status, and gaming, youth who participated in a sports-dominant activity pattern for 2 or more years had significantly lower 11th grade odds of being at-risk for overweight/obesity compared to youth in all other activity patterns. Youth of all other activity patterns had similar odds of being at-risk as Low-Activity youth and each other. Understanding the relations of OST to youth healthy weight is a critical first step in developing healthy OST settings. Copyright © 2013 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  9. Treatment timing of MARA and fixed appliance therapy of Class II malocclusion.

    Science.gov (United States)

    Ghislanzoni, Luis Tomas Huanca; Baccetti, Tiziano; Toll, Douglas; Defraia, Efisio; McNamara, James A; Franchi, Lorenzo

    2013-06-01

    The objective of this study is to evaluate the effect of timing on Mandibular Anterior Repositioning Appliance (MARA) and fixed appliance treatment of Class II malocclusion in a prospective clinical trial. The treated sample consisted of 51 consecutively treated patients at prepubertal (n = 21), pubertal (n = 15), and postpubertal (n = 15) stages of development. Control groups for the three treated groups were generated from growth data of untreated Class II subjects. Lateral cephalograms were digitized and superimposed via cephalometric software at T1 (pre-treatment) and T2 (after comprehensive treatment). The T1-T2 changes in the treated groups were compared to those in their corresponding control groups with Mann-Whitney tests with Bonferroni correction. Mandibular elongation was greater at the pubertal stage (Co-Gn +2.6 mm, with respect to controls). Headgear effect on the maxilla was greater in the pre-peak sample (Co-A -1.9 mm, with respect to controls). Dentoalveolar compensations (proclination of lower incisors, extrusion and mesialization of lower molars, and reduction in the overbite) were significant in the pre-peak and post-peak groups. Optimal timing for Class II treatment with MARA appliance is at the pubertal growth spurt, with enhanced mandibular skeletal changes and minimal dentoalveolar compensations.

  10. Regulation of gonadal sex ratios and pubertal development by the thyroid endocrine system in zebrafish (Danio rerio).

    Science.gov (United States)

    Sharma, Prakash; Patiño, Reynaldo

    2013-04-01

    We examined associations between thyroid condition, gonadal sex and pubertal development in zebrafish. Seventy-two-hour postfertilization larvae were reared in untreated medium or in the presence of goitrogens (sodium perchlorate, 0.82 mM; methimazole, 0.15 and 0.3 mM) or thyroxine (1 and 10 nM) for 30 days. Thyrocyte height, gonadal sex and gonadal development were histologically determined at 45 and 60 days postfertilization (dpf). Thyrocyte hypertrophy, an index of hypothyroidism, was observed at 45 and 60 dpf in perchlorate-treated but only at 45 dpf in methimazole-treated fish. Similarly, gonadal sex ratios were biased toward ovaries relative to control animals at 45 and 60 dpf in perchlorate-treated fish but only at 45 dpf in methimazole-treated fish. Gonadal sex ratios were biased toward testes at 45 and 60 dpf in thyroxine-treated fish. Spermatogenesis was delayed in testes from goitrogen-treated fish at 60 dpf relative to control values, but was unaffected in testes from thyroxine-treated individuals. Oogenesis seemed to be nonspecifically delayed in all treatments relative to control at 60 dpf. This study confirmed the previously reported association between hypothyroid condition and ovarian-skewed ratios, and hyperthyroid condition and testicular-skewed ratios, and also showed that male pubertal development is specifically delayed by experimental hypothyroidism. The simultaneous recovery from the hypothyroid and ovary-inducing effects of methimazole by 60 dpf (27 days post-treatment) suggests that the ovary-skewing effect of goitrogens is reversible when thyroid conditions return to basal levels before developmental commitment of gonadal sex. Conversely, the masculinizing effect of hyperthyroidism seems to be stable and perhaps permanent. Published by Elsevier Inc.

  11. Regulation of gonadal sex ratios and pubertal development by the thyroid endocrine system in zebrafish (Danio rerio)

    Science.gov (United States)

    Sharma, Prakash; Patino, Reynaldo

    2013-01-01

    We examined associations between thyroid condition, gonadal sex and pubertal development in zebrafish. Seventy-two-hour postfertilization larvae were reared in untreated medium or in the presence of goitrogens (sodium perchlorate, 0.82 mM; methimazole, 0.15 and 0.3 mM) or thyroxine (1 and 10 nM) for 30 days. Thyrocyte height, gonadal sex and gonadal development were histologically determined at 45 and 60 days postfertilization (dpf). Thyrocyte hypertrophy, an index of hypothyroidism, was observed at 45 and 60 dpf in perchlorate-treated but only at 45 dpf in methimazole-treated fish. Similarly, gonadal sex ratios were biased toward ovaries relative to control animals at 45 and 60 dpf in perchlorate-treated fish but only at 45 dpf in methimazole-treated fish. Gonadal sex ratios were biased toward testes at 45 and 60 dpf in thyroxine-treated fish. Spermatogenesis was delayed in testes from goitrogen-treated fish at 60 dpf relative to control values, but was unaffected in testes from thyroxine-treated individuals. Oogenesis seemed to be nonspecifically delayed in all treatments relative to control at 60 dpf. This study confirmed the previously reported association between hypothyroid condition and ovarian-skewed ratios, and hyperthyroid condition and testicular-skewed ratios, and also showed that male pubertal development is specifically delayed by experimental hypothyroidism. The simultaneous recovery from the hypothyroid and ovary-inducing effects of methimazole by 60 dpf (27 days post-treatment) suggests that the ovary-skewing effect of goitrogens is reversible when thyroid conditions return to basal levels before developmental commitment of gonadal sex. Conversely, the masculinizing effect of hyperthyroidism seems to be stable and perhaps permanent.

  12. Pubertal development and fertility in survivors of childhood acute myeloid leukemia treated with chemotherapy only

    DEFF Research Database (Denmark)

    Molgaard-Hansen, Lene; Skou, Anne-Sofie; Juul, Anders

    2013-01-01

    More than 60% of children with acute myeloid leukemia (AML) become long-term survivors. Most are cured using chemotherapy without hematopoietic stem cell transplantation (HSCT). We report on pubertal development and compare self-reported parenthood among AML survivors and their siblings....

  13. BMI percentile-for-age overestimates adiposity in early compared with late maturing pubertal children

    DEFF Research Database (Denmark)

    Sørensen, Kaspar; Juul, Anders

    2015-01-01

    and bioelectric impedance analyses (BIA) were used to estimate adiposity. Clinical pubertal markers (Tanner stages and testicular volume) were evaluated. LH, FSH, estradiol, testosterone, SHBG and IGF1 levels were determined by immunoassays. RESULTS: In all age groups, higher BMI (all 1 year age-groups, P ≤ 0...

  14. The Interplay between Gaze Following, Emotion Recognition, and Empathy across Adolescence; a Pubertal Dip in Performance?

    NARCIS (Netherlands)

    van Rooijen, R.; Junge, C.M.M.; Kemner, C.

    2018-01-01

    During puberty a dip in face recognition is often observed, possibly caused by heightened levels of gonadal hormones which in turn affects the re-organization of relevant cortical circuitry. In the current study we investigated whether a pubertal dip could be observed in three other abilities

  15. The Relationship among Pubertal Stage, Age, and Drinking in Adolescent Boys and Girls

    Science.gov (United States)

    Faden, Vivian B.; Ruffin, Beverly; Newes-Adeyi, Gabriella; Chen, Chiung

    2010-01-01

    This study used data from the Third National Household and Nutrition Examination Survey (NHANES) to examine the association between pubertal status (Tanner staging for boys and girls and menarche for girls) and alcohol use in a nationally representative sample of youths ages 12 to 17. Logistic regression was used to model the relationship. In…

  16. Insulin resistance in obese pre-pubertal children: Relation to body ...

    African Journals Online (AJOL)

    Heba Elsedfy

    2014-04-16

    Apr 16, 2014 ... of pre-pubertal obese children, and to investigate the relation- .... children P 10 years, HDL-Cholesterol <35 mg/dl) [18]. .... HDL: high density lipoprotein, TG: triglycerides, IFG: impaired fasting glucose, IGT: impaired glucose ...

  17. Pubertal maturation and sex steroids are related to alcohol use in adolescents

    NARCIS (Netherlands)

    Water, E. de; Braams, B.R.; Crone, E.A.; Peper, J.S.

    2013-01-01

    Adolescents often show risk-taking behavior, including experimentation with alcohol. Previous studies have shown that advanced pubertal maturation is related to increased alcohol use in adolescents, even when controlling for age. Little is known about the underlying mechanisms of this relation

  18. Salivary testosterone concentrations in pubertal ICSI boys compared with spontaneously conceived boys

    NARCIS (Netherlands)

    Belva, F.; Bonduelle, M.; Schiettecatte, J.; Tournaye, H.; Painter, R. C.; Devroey, P.; de Schepper, J.

    2011-01-01

    BACKGROUND: To date, no data exist about Leydig cell function of pubertal boys born after ICSI. To evaluate a potential risk of gonadal dysfunction in children born from fathers with compromised fertility, testicular function was assessed by the measurement of salivary testosterone. METHODS: Morning

  19. Tamoxifen therapy for the management of pubertal gynecomastia: a systematic review

    NARCIS (Netherlands)

    Lapid, Oren; van Wingerden, Jan J.; Perlemuter, Leon

    2013-01-01

    Objective: A systematic review to assess the efficacy of tamoxifen in the management of idiopathic pubertal gynecomastia. Data sources: Searches were conducted using the databases of Medline (search engine PubMed) and Web of Science (R). Study selection: Studies reporting the use of Tamoxifen for

  20. IPRODIONE DELAYS MALE RAT PUBERTAL DEVELOPMENT, REDUCING SERUM TESTOSTERONE AND EX VIVO TESTOSTERONE PRODUCTION

    Science.gov (United States)

    Iprodione (IPRO) is a dichlorophenyl dicarboximide fungicide similar to the androgen receptor (AR) antagonist vinclozolin. The current studies were designed to determine if IPRO would delay male rat pubertal development like vinclozolin and to identify the mechanism(s) of action...

  1. Normal Pubertal Development in Daughters of Women With PCOS: A Controlled Study.

    Science.gov (United States)

    Legro, Richard S; Kunselman, Allen R; Stetter, Christy M; Gnatuk, Carol L; Estes, Stephanie J; Brindle, Eleanor; Vesper, Hubert W; Botelho, Julianne C; Lee, Peter A; Dodson, William C

    2017-01-01

    Daughters of women with polycystic ovary syndrome (PCOS) are thought to be at increased risk for developing stigmata of the syndrome, but the ontogeny during puberty is uncertain. We phenotyped daughters (n = 76) of mothers with PCOS and daughters (n = 80) from control mothers for reproductive and metabolic parameters characteristic of PCOS. We performed a matched case/control study at Penn State Hershey Medical Center that included non-Hispanic, white girls 4 to 17 years old. We obtained birth history, biometric, ovarian ultrasounds, whole-body dual-energy X-ray absorptiometry scan for body composition, 2-hour glucose challenged salivary insulin levels, and two timed urinary collections (12 hours overnight and 3 hours in the morning) for gonadotropins and sex steroids. We measured integrated urinary levels of adrenal (dehydroepiandrosterone sulfate) and ovarian [testosterone (TT)] steroids. Other endpoints included integrated salivary insulin levels and urinary luteinizing hormone levels. There were no differences in detection rates or mean levels for gonadotropins and sex steroids in timed urinary collections between PCOS daughters and control daughters, nor were there differences in integrated salivary insulin levels. Results showed that 69% of Tanner 4/5 PCOS daughters vs 31% of control daughters had hirsutism defined as a Ferriman-Gallwey score >8 (P = 0.04). There were no differences in body composition as determined by dual-energy X-ray absorptiometry between groups in the three major body contents (i.e., bone, lean body mass, and fat) or in ovarian volume between groups. Matched for pubertal stage, PCOS daughters have similar levels of urinary androgens and gonadotropins as well as glucose-challenged salivary insulin levels. Copyright © 2017 by the Endocrine Society

  2. Tunneling times and the Hartman effect revisited

    Energy Technology Data Exchange (ETDEWEB)

    Olkhovsky, Vladislav S. [Ukrainian Academy of Sciences, Kiev (Ukraine). Inst. for Nuclear Research]|[Istituto Nazionale di Fisica Nucleare, Catania (Italy); Recami, Erasmo [Universidade Estadual de Campinas, SP (Brazil). Dept. de Matematica Aplicada]|[Istituto Nazionale di Fisica Nucleare, Milano (Italy); Raciti, Fabio [Catania Univ. (Italy). Dipt. di Fisica; Zaichenko, Aleksandr K. [Ukrainian Academy of Sciences, Kiev (Ukraine)

    1995-05-01

    In a recent review paper we proposed, within conventional quantum mechanics, new definitions for the sub-barrier tunnelling and reflection times. Aims of the present paper are: presenting and analysing the results of various numerical calculations (based on our equations) on the penetration and return times < {tau}Pen >, <{tau}Ret >, during tunneling inside a rectangular potential barrier, for various penetration depths x{sub f}; putting forth and discussing suitable definitions, besides of the mean values, also of the variances (or dispersions) D {sup {tau}}T D {sup {tau}}R for the time durations of transmission and reflection process; mentioning that our definition < {sup {tau}}T > for the average transmission time results to constitute an improvement of the ordinary dwell-time {tau}{sup Dw} formula; commenting upon some recent criticism by C.R. Leavens, on the basis of our new numerical results. We stress that our numerical evaluations confirm that our approach implied and implies, the existence of the Hartman effect: an effect that in these days (due to the theoretical connections between tunneling and evanescent wave propagation) is receiving - at Cologne, Berkeley, Florence and Vienna- indirect, but quite interesting, experimental verifications. At last, we briefly analyze some other definitions of tunnelling times. (author). 24 refs., 5 figs.

  3. Tunneling times and the Hartman effect revisited

    International Nuclear Information System (INIS)

    Olkhovsky, Vladislav S.; Recami, Erasmo; Raciti, Fabio

    1995-05-01

    In a recent review paper we proposed, within conventional quantum mechanics, new definitions for the sub-barrier tunnelling and reflection times. Aims of the present paper are: presenting and analysing the results of various numerical calculations (based on our equations) on the penetration and return times , , during tunneling inside a rectangular potential barrier, for various penetration depths x f ; putting forth and discussing suitable definitions, besides of the mean values, also of the variances (or dispersions) D τ T D τ R for the time durations of transmission and reflection process; mentioning that our definition τ T > for the average transmission time results to constitute an improvement of the ordinary dwell-time τ Dw formula; commenting upon some recent criticism by C.R. Leavens, on the basis of our new numerical results. We stress that our numerical evaluations confirm that our approach implied and implies, the existence of the Hartman effect: an effect that in these days (due to the theoretical connections between tunneling and evanescent wave propagation) is receiving - at Cologne, Berkeley, Florence and Vienna- indirect, but quite interesting, experimental verifications. At last, we briefly analyze some other definitions of tunnelling times. (author). 24 refs., 5 figs

  4. Time and interference: Effects on working memory.

    Science.gov (United States)

    Botto, Marta; Palladino, Paola

    2016-05-01

    This study tested predictions from the time-based resource-sharing (TBRS) model with a classical verbal working memory (WM) task, where target and non-target information interfere strongly with each other. Different predictions can be formulated according to the dominant perspectives (TBRS and interference hypothesis) on the role of inhibitory control in WM task performance. Here, we aimed to trace the activation of irrelevant information, examining priming effects in a lexical decision task immediately following WM recall. Results indicate the roles of both time and interference constraints in determining task performance. In particular, the role of time available seemed crucial at the highest WM loads (i.e., 3 and 4 memoranda). These were also associated with a higher activation of no-longer-relevant information but, in this case, independently from time available for processing. © 2015 The British Psychological Society.

  5. Time- & Load-Dependence of Triboelectric Effect.

    Science.gov (United States)

    Pan, Shuaihang; Yin, Nian; Zhang, Zhinan

    2018-02-06

    Time- and load-dependent friction behavior is considered as important for a long time, due to its time-evolution and force-driving characteristics. However, its electronic behavior, mainly considered in triboelectric effect, has almost never been given the full attention and analyses from the above point of view. In this paper, by experimenting with fcc-latticed aluminum and copper friction pairs, the mechanical and electronic behaviors of friction contacts are correlated by time and load analyses, and the behind physical understanding is provided. Most importantly, the difference of "response lag" in force and electricity is discussed, the extreme points of coefficient of friction with the increasing normal loads are observed and explained with the surface properties and dynamical behaviors (i.e. wear), and the micro and macro theories linking tribo-electricity to normal load and wear (i.e. the physical explanation between coupled electrical and mechanical phenomena) are successfully developed and tested.

  6. Age-dependent exposure to radioactive iodine (131I) in the thyroid and total body of newborn, pubertal and adult fischer 344 rats

    International Nuclear Information System (INIS)

    Nitta, Yumiko; Fujimoto, Nariaki; Kamiya, Kenji; Hoshi, Masaharu; Endo, Satoru

    2001-01-01

    Female rats of the Fischer 344 strain at ages of 1, 4 and 9 weeks were exposed to 131 I intraperitoneally with activities of 0.38, 1.03 and 3.42 kBq per gram of body weight under the condition of iodine deficiency. The absorbed doses in the thyroid increased linearly depending on the injected activities. Irradiation at 1 week old caused heavier exposure than those at 4 and 9 weeks old by 7.5 and 7.7 times, respectively; however, damage of the thyroid tissue was more obvious in the 4-week-old groups than in the 1-week-old groups. The absorbed doses in the total body were proportional to the square root of the injected activities. The one-week-old groups were exposed more heavily than the 4- and 9-week-old groups by 3.6 and 4.7 times, respectively, shown by the slow excretion of 131 I with the values of effective half-life of 131 I activity (T eff ). An IDD-treatment was not so effective to enhance the 131 I absorption in the total body, as in the thyroid. No matter how the iodine concentration in the blood changed, the 1-week-old groups could not react to normalize the level. We drew standard curves, which enabled us to estimate the absorbed doses in the thyroid and the total body in the case of the injected activities of 131 I for the newborn, pubertal and adult rats. (author)

  7. [A survey of pubertal development in children born with assisted reproductive technology].

    Science.gov (United States)

    Liu, Zi-Yuan; Wang, Xin-Li; Han, Tong-Yan; Cui, Yun-Pu; Wang, Xue-Mei; Tong, Xiao-Mei; Song, Yi; Wang, Hai-Jun; Li, Song

    2017-06-01

    To investigate the status of pubertal development in children born with assisted reproductive technology (ART). A retrospective analysis was performed on the pubertal development data of children born with ART in Peking University Third Hospital from 1994 to 2003 (ART group). The data in the cross-sectional study "Reports on the Physical Fitness and Health Research of Chinese School Students in 2010" were used as a control. The age at menarche and the age at spermarche were compared between the two groups. The status of pubertal development in the overweight and obese children in the ART group was evaluated to investigate the correlation between pubertal development and body mass index (BMI). A total of 200 children born with ART were enrolled in this study, and 72 of them (41 males and 31 females) completed the survey (response rate=36.0%). In the ART group, the mean age at spermarche and the mean age at menarche were 13.9 years (95%CI: 13.7-14.3 years) and 12.2 years (95%CI: 11.8-12.6 years), respectively. There were no significant differences in the age at spermarche and the age at menarche between the ART and control groups (P>0.05). In the ART group, there were no significant differences in the age at spermarche and the age at menarche between the overweight and obese children and the normal weight children (P>0.05). There were also no significant differences in overweight rate and obesity rate between the children in the ART group and the adolescents in Beijing (P>0.05). In the ART group, there was no significant correlation between the age at spermarche or menarche and BMI (P>0.05). No delayed or precocious puberty is observed in children born with ART. This is consistent with the normal control data. And there is no significant correlation between pubertal development and BMI in children born with ART.

  8. Ovarian function following pelvic irradiation in prepubertal and pubertal girls and young adult women

    Energy Technology Data Exchange (ETDEWEB)

    Schuck, A.; Hamelmann, V. [University Hospital Muenster (Germany). Dept. of Radiotherapy; Braemswig, J.H. [University Hospital Muenster (DE). Dept. of Pediatrics] [and others

    2005-08-01

    Purpose: To analyze the effect of pelvic radiotherapy on ovarian function in prepubertal and pubertal girls and young adult women. Patients and methods: In a retrospective monoinstitutional analysis, patients <30 years of age at diagnosis were included who had been irradiated between 1979 and 1998. The main tumor types were Hodgkin's disease (38%), Erwing's sarcoma (20%) and nephroblastoma (11%). Patients were classified into three groups according to the position of the ovary in relation to the radiation portals. Group 1 was defined by direct irradiation of both ovaries. Group 2 patients were included with both ovaries potentially located in the radiation portals. In group 3, at least one ovary was not directly irradiated. The median follow-up was 128 months. Results: 16 of 55 analyzed patients were categorized in group 1. In ten of these patients, hormone status was evaluable. The ovarian doses were {>=}15 Gy. Except for one patient treated with 15 Gy all developed hormone failure. Eight of 14 patients of group 2 were evaluable. Seven of these patients developed ovarian failure. 19 of 24 patients in group 3 were evaluable. Nine of these patients developed ovarian failure. The observed difference in the rate of ovarian failure between the groups is statistifcally significant (p=0.045). Conclusion: All patients receiving >15 Gy to the ovaries developed hormone failure. In one case of a patient receiving an ovarian dose of 15 Gy, hormone failure was not found. In case of pelvic irradiation excluding at least one ovary, approximately half of the patients developed ovarian dysfunction, probably also due to the effects of polychemotherapy. (orig.)

  9. Bone turnover markers during pubertal development: relationships with growth factors and adipocytokines.

    Science.gov (United States)

    Jürimäe, Jaak; Mäestu, Jarek; Jürimäe, Toivo

    2010-01-01

    The rapid increase in skeletal mass that occurs during puberty is caused by increases in longitudinal growth as well as cortical thickness. The measurement of growth changes during puberty using two-dimensional (dual-energy X-ray absorptiometry) and/or three-dimensional (computed tomography, magnetic resonance imaging) measurement devices provides only a static representation of bone tissue parameters. The measurement of bone turnover markers provides a more dynamic picture of the nature of bone tissue that can be repeated at much shorter intervals during puberty. The bone turnover markers are products of osteoblasts and osteoclasts which can be measured in urine or blood. The increase in different markers of bone turnover coincides with the pubertal growth spurt and thereafter markers decline until they converge into adult values. The initiation of puberty is accompanied by increases in androgens and estrogens. The effects of sex hormones on bone mineral accrual are mediated mainly by growth hormone and insulin-like growth factor-1, but they also exert a direct effect on bone metabolism. Important determinants of bone mineral accrual during puberty include optimal nutritional status, body composition parameters and physical activity pattern. All of these determinants are related to the state of energy balance, while peripheral indicators of energy balance, such as different growth factors and adipocytokines, may also have a positive influence of the growing skeleton. Taken together, bone mineral accrual during puberty is a complex interaction between physical activity pattern, various body composition parameters, specific growth factors and adipocytokines, and also sex hormones. Copyright © 2010 S. Karger AG, Basel.

  10. The relations of age and pubertal development with cortisol and daily stress in youth at clinical risk for psychosis.

    Science.gov (United States)

    Moskow, Danielle M; Addington, Jean; Bearden, Carrie E; Cadenhead, Kristin S; Cornblatt, Barbara A; Heinssen, Robert; Mathalon, Daniel H; McGlashan, Thomas H; Perkins, Diana O; Seidman, Larry J; Tsuang, Ming T; Cannon, Tyrone D; Woods, Scott W; Walker, Elaine F

    2016-04-01

    Prodromal syndromes often begin in adolescence - a period of neurodevelopmental changes and heightened stress sensitivity. Research has shown elevated stress and cortisol in individuals at clinical high risk (CHR) for psychosis. This cross-sectional study examined relations of age and pubertal status with cortisol and self-reported stress in healthy controls (HCs) and CHR adolescents. It was hypothesized that the relations of age and pubertal stage with cortisol and stress would be more pronounced in CHR youth. Participants were 93 HCs and 348 CHR adolescents from the North American Prodrome Longitudinal Study (NAPLS). At baseline, measures of stress (Daily Stress Inventory - DSI), Tanner stage (TS), and salivary cortisol were obtained. ANCOVA revealed increased DSI scores with age for both groups, and higher DSI scores in CHR adolescents than HCs, with a more pronounced difference for females. Contrary to prediction, with age controlled, HCs showed greater TS-related DSI increases. Analysis of cortisol showed no significant interactions, but a main effect of age and a trend toward higher cortisol in the CHR group. Correlations of cortisol with TS were higher in HC than CHR group. Stress measures increased with age in HC and CHR adolescents, and DSI scores also increased with TS in HCs. The results do not support a more pronounced age or TS increase in stress measures in CHR adolescents, but instead suggest that stress indices tend to be elevated earlier in adolescence in the CHR group. Potential determinants of findings and future directions are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Perinatal testosterone contributes to mid-to-post pubertal sex differences in risk for binge eating in male and female rats.

    Science.gov (United States)

    Culbert, Kristen M; Sinclair, Elaine B; Hildebrandt, Britny A; Klump, Kelly L; Sisk, Cheryl L

    2018-02-01

    Exposure to testosterone early in life may contribute to sex differences and pubertal changes in risk for eating pathology (i.e., females > males, after pubertal onset). Specifically, perinatal testosterone permanently alters brain structure/function and drives the masculinization of several sex-differentiated behaviors. However, the effects of perinatal testosterone are often not evident until puberty when increases in gonadal hormones activate the expression of sex typical behavior, including eating behaviors (e.g., chow intake; saccharin preference) in rodents. Despite perinatal testosterone's masculinizing effects on general feeding behavior, it remains unknown if perinatal testosterone exposure contributes to sex differences in pathological eating. The current study addressed this gap by examining whether perinatal testosterone exposure decreases risk for binge eating proneness after pubertal onset in male and female rats. Sprague-Dawley rats (n = 40 oil-treated control females; n = 39 testosterone-treated females; n = 40 oil-treated control males) were followed longitudinally across pre-to-early puberty, mid-to-late puberty, and adulthood. The binge eating prone (BEP)/binge eating resistant (BER) rodent model was used to identify individual differences in binge eating proneness across the dimensional spectrum. As expected, testosterone-treated females and control males showed masculinized (i.e., lower) risk for binge eating as compared to control females, but only after midpuberty. These animal data are significant in suggesting that perinatal testosterone exposure may protect against binge eating and underlie sex differences in binge eating prevalence during and after puberty. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  12. Sex steroids and brain structure in pubertal boys and girls: a mini-review of neuroimaging studies

    NARCIS (Netherlands)

    Peper, J.S.; Hulshoff Pol, H.E.; Crone, E.A.; van Honk, J.

    2011-01-01

    Puberty is an important period during development hallmarked by increases in sex steroid levels. Human neuroimaging studies have consistently reported that in typically developing pubertal children, cortical and subcortical gray matter is decreasing, whereas white matter increases well into

  13. Facing changes and changing faces in adolescence: a new model for investigating adolescent-specific interactions between pubertal, brain and behavioral development.

    Science.gov (United States)

    Scherf, K Suzanne; Behrmann, Marlene; Dahl, Ronald E

    2012-04-01

    Adolescence is a time of dramatic physical, cognitive, emotional, and social changes as well as a time for the development of many social-emotional problems. These characteristics raise compelling questions about accompanying neural changes that are unique to this period of development. Here, we propose that studying adolescent-specific changes in face processing and its underlying neural circuitry provides an ideal model for addressing these questions. We also use this model to formulate new hypotheses. Specifically, pubertal hormones are likely to increase motivation to master new peer-oriented developmental tasks, which will in turn, instigate the emergence of new social/affective components of face processing. We also predict that pubertal hormones have a fundamental impact on the re-organization of neural circuitry supporting face processing and propose, in particular, that, the functional connectivity, or temporal synchrony, between regions of the face-processing network will change with the emergence of these new components of face processing in adolescence. Finally, we show how this approach will help reveal why adolescence may be a period of vulnerability in brain development and suggest how it could lead to prevention and intervention strategies that facilitate more adaptive functional interactions between regions within the broader social information processing network. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Facing changes and changing faces in adolescence: A new model for investigating adolescent-specific interactions between pubertal, brain and behavioral development

    Science.gov (United States)

    Scherf, K. Suzanne; Behrmann, Marlene; Dahl, Ronald E.

    2015-01-01

    Adolescence is a time of dramatic physical, cognitive, emotional, and social changes as well as a time for the development of many social-emotional problems. These characteristics raise compelling questions about accompanying neural changes that are unique to this period of development. Here, we propose that studying adolescent-specific changes in face processing and its underlying neural circuitry provides an ideal model for addressing these questions. We also use this model to formulate new hypotheses. Specifically, pubertal hormones are likely to increase motivation to master new peer-oriented developmental tasks, which will in turn, instigate the emergence of new social/affective components of face processing. We also predict that pubertal hormones have a fundamental impact on the reorganization of neural circuitry supporting face processing and propose, in particular, that, the functional connectivity, or temporal synchrony, between regions of the face-processing network will change with the emergence of these new components of face processing in adolescence. Finally, we show how this approach will help reveal why adolescence may be a period of vulnerability in brain development and suggest how it could lead to prevention and intervention strategies that facilitate more adaptive functional interactions between regions within the broader social information processing network. PMID:22483070

  15. Serum levels of INSL3, AMH, Inhibin B and Testosterone during pubertal transition in healthy boys

    DEFF Research Database (Denmark)

    Lindhardt Johansen, Marie; Anand-Ivell, Ravinder; Mouritsen, Annette

    2014-01-01

    to luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, inhibin B, and anti-Müllerian hormone (AMH) during puberty in healthy boys.MethodsTen boys were included from the longitudinal part of the COPENHAGEN Puberty Study. Pubertal evaluation, including testicular volume, was performed...... and blood samples drawn every 6 months for 5 years. Serum concentrations of testosterone were determined by a newly developed LC-MS/MS method, and serum concentrations of INSL3, AMH, inhibin B, FSH and LH, respectively, were determined by validated immunoassays.ResultsSerum INSL3 levels increased...... progressively with increasing age, pubertal onset and testicular volume. In six of ten boys, LH increased prior to the first observed increase in INSL3. In the remaining four boys, the increase in LH and INSL3 was observed at the same examination. The increases in serum concentrations of LH, testosterone...

  16. The association of pain and depression in preadolescent girls: moderation by race and pubertal stage.

    Science.gov (United States)

    Keenan, Kate; Hipwell, Alison E; Hinze, Amanda E; Babinski, Dara E

    2009-08-01

    To test whether an association between pain response and depression in females is present during preadolescence using a controlled pain stimulus and a clinically relevant assessment of depressive symptoms. In a sample of 232 girls, pain threshold and tolerance were assessed at age 10 years using the cold pressor task, and a diagnostic interview was used to assess depression symptoms at 10 and 11 years of age. Response to pain at age 10 was associated with depressive symptoms at ages 10 and 11; race and pubertal stage moderated the association. Pain response and depression were more strongly associated among girls who had reached advanced stages of pubertal development and among European American girls. The results add to the existing literature on the co-occurrence of depression and pain by demonstrating modest but consistent concurrent and prospective associations between response to pain and depression among girls during preadolescence.

  17. Giant fibroadenoma of the breast in a pre-pubertal girl: a case report

    Directory of Open Access Journals (Sweden)

    Sunder Goyal

    2014-02-01

    Full Text Available Juvenile fibroadenoma comprises about 4% of the total fibroadenomas. The incidence of giant juvenile fibroadenomas is merely 0.5% of all the fibroadenomas. Bilateral giant juvenile fibroadenomas are extremely rare. We are presenting a case of giant juvenile fibroadenomas in an 11-year-old pre-pubertal girl. The diagnosis was made on fine-needle aspiration cytology which was confirmed on histopathology. As these tumors are mostly benign, breast-conserving surgery is done so that patient can lead a normal life without psychological trauma.-----------------------------------Cite this article as: Goyal S, Garg G, Narang S. Giant fibroadenoma of the breast in a pre-pubertal girl: a case report. Int J Cancer Ther Oncol 2014; 2(1:020113.DOI: http://dx.doi.org/10.14319/ijcto.0201.13

  18. [Craniopharyngioma and Klinefelter syndrome during the pubertal transition: A diagnostic challenge].

    Science.gov (United States)

    Mocarbel, Yamile; Arébalo de Cross, Graciela; Lebrethon, Marie C; Thiry, Albert; Beckersd, Albert; Valdes-Socin, Hernan

    2017-04-01

    Craniopharyngioma is the most common pituitary tumor in childhood. It can compromise the pubertal development because of its evolution or treatment. Syndrome of Klinefelter is the most common cause of hipergonadotrophic hypogonadism in males. The concomitant presentation of both entities is extremely low (1/109) and the pathophysiological association is questionned. We present the case of a 18-year-old Belgian patient. He had a diagnosis of craniopharyngioma in childhood and he presented with panhypopituitarism after radiotherapy and surgical treatment. At the age of 14, he started pubertal induction with gonadotropin therapy without clinical response. Asociación de craneofaringioma y síndrome de Klinefelter en la transición puberal: un desafío diagnóstico Craniopharyngioma and Klinefelter syndrome during the pubertal transition: A diagnostic challenge A genetic evaluation confirmed a homogeneous 47, XXY karyotype. Failure of exogenous gonadotropin therapy revealed the hidden association of primary and secondary hypogonadism, demonstrating the importance of the followup and a multidisciplinary approach in these patients. Sociedad Argentina de Pediatría.

  19. The relationship between pubertal gynecomastia, prostate specific antigen, free androgen index, SHBG and sex steroids.

    Science.gov (United States)

    Kilic, Mustafa; Kanbur, Nuray; Derman, Orhan; Akgül, Sinem; Kutluk, Tezer

    2011-01-01

    To investigate the relationships between pubertal gynecomastia, prostate-specific antigen (PSA), free androgen index (FAI), sex hormone-binding globulin (SHBG) and sex steroids. A total of 61 male adolescents (10-17 years old; mean: 13.67 +/- 1.08) with gynecomastia were enrolled into the study group. A total of 65 healthy age-matched adolescents were included in the control group. Body mass index (BMI), Tanner staging, testis volume, stretched penis length (SPL) and bone age were evaluated. Serum follicle-stimulating hormone, luteinizing hormone (LH), estradiol (E2), testosterone, free testosterone, SHBG, PSA levels were determined and FAI was calculated. In the study group, free testosterone (p = 0.012) and FAI (p = 0.05) were significantly lower than the control group. In the control group, SHBG levels decreased (p 0.05). High FAI was found to decrease the risk of gynecomastia (odds ratio: 0.211, 95% confidence interval: 0.064-0.694, p = 0.01). PSA showed a positive correlation with FAI, free testosterone, Tanner staging, testosterone, E2 and LH levels. PSA is a good indicator of androgen activity during puberty. However, owing to FAI remaining as the single significant variable for pubertal gynecomastia, we suggest that it is still the best parameter to elucidate the etiopathogenesis of gynecomastia as well as other pubertal developmental abnormalities in male adolescents, and further longitudinal studies are needed to investigate the relationships between PSA and FAI in puberty.

  20. Mutational Analysis of TAC3 and TACR3 Genes in Patients with Idiopathic Central Pubertal Disorders

    Science.gov (United States)

    Tusset, Cintia; Noel, Sekoni D.; Trarbach, Ericka B.; Silveira, Letícia F. G.; Jorge, Alexander A. L.; Brito, Vinicius N.; Cukier, Priscila; Seminara, Stephanie B.; de Mendonça, Berenice B.; Kaiser, Ursula B.; Latronico, Ana Claudia

    2013-01-01

    Aim To investigate the presence of variants in the TAC3 and TACR3 genes, which encode NKB and its receptor (NK3R), respectively, in a large cohort of patients with idiopathic central pubertal disorders. Patients and Methods Two hundred and thirty seven patients were studied: 114 with central precocious puberty (CPP), 73 with normosmic isolated hypogonadotropic hypogonadism (IHH) and 50 with constitutional delay of growth and puberty (CDGP). The control group consisted of 150 Brazilian individuals with normal pubertal development. Genomic DNA was extracted from peripheral blood and the entire coding region of both TAC3 and TACR3 genes were amplified and automatically sequenced. Results We identified one variant (p.A63P) in NKB and four variants, p.G18D, p.L58L (c.172C>T), p.W275* and p.A449S in NK3R, which were absent in the control group. The p.A63P variant was identified in a girl with CPP, and p.A449S in a girl with CDGP. The known p.G18D, p.L58L and p.W275* variants were identified in three unrelated males with normosmic IHH. Conclusion Rare variants in the TAC3 and TACR3 genes were identified in patients with central pubertal disorders. Loss-of-function variants of TACR3 were associated with the normosmic IHH phenotype. PMID:23329188

  1. [Pubertal maturation, physical self-esteem and sexuality in a sample of French adolescents].

    Science.gov (United States)

    Potard, C; Courtois, R; Clarisse, R; Le Floc'h, N; Thomine, M; Réveillère, C

    2016-04-01

    The aim of this study was to explore the links between pubertal maturation, physical self-esteem and sexuality in adolescence, differentiating between boys and girls. The sample was comprised of 312 French secondary school children (seventh and ninth grades); 52.6 % (n=164) of whom were girls. Participants answered three self-evaluation questionnaires: the scale of sexuality (interests, emotions, relationships: IERS) in prime adolescence (12 to 15 years); (b) the self-administered rating scale for pubertal development and (c) the Physical Self-Description Questionnaire (PSDQ). Pubertal maturation was associated with higher scores on "Flirting with the aim of having sexual relations" and "Going out with someone", and a drop in overall and physical self-esteem, mainly in socially valued domains, namely "Body fat" for girls, and "Strength" and "Health" for boys. Overall physical self-esteem was associated with "Going out with someone" and "Flirting with the aim of having sexual relations" in boys. Physical changes at puberty induce two distinct trends in adolescents: sexual exploration and discovery (genitalized body), and self-depreciation (social body). Copyright © 2015 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

  2. Internet Effects in Times of Political Crisis

    Science.gov (United States)

    Baccini, Leonardo; Sudulich, Laura; Wall, Matthew

    2016-01-01

    This paper evaluates the influence of online news consumption on attitudes toward the European Union in a context of protracted economic crisis. Using data from the 2011 Irish National Election Study, we combine location-specific information on broadband availability with respondent geo-location data, which facilitates causal inference about the effects of online news consumption via instrumental variable models. Results show that Irish citizens who source political information online are more prone to blame the EU for the poor state of the economy than those who do not. There is evidence of preference reinforcement among those with negative predispositions toward the EU, but not among pro-EU citizens. We complement this analysis with a study of voting behavior in the European Fiscal Compact Referendum, employing a similar methodological approach. The results from this second survey confirm the anti-EU influence of online news consumption among Irish citizens, although evidence suggests a pro-EU effect among voters who browsed the website of the politically neutral Irish Referendum Commission. Our paper contributes to the literature on public opinion, the EU, and political attitudes in times of crisis. PMID:27274571

  3. Long-term skeletal and dental effects and treatment timing for functional appliances in Class II malocclusion.

    Science.gov (United States)

    Franchi, Lorenzo; Pavoni, Chiara; Faltin, Kurt; McNamara, James A; Cozza, Paola

    2013-03-01

    To analyze the long-term skeletal and dentoalveolar effects and to evaluate treatment timing of Class II treatment with functional appliances followed by fixed appliances. A group of 40 patients (22 females and 18 males) with Class II malocclusion consecutively treated either with a Bionator or an Activator followed by fixed appliances was compared with a control group of 20 subjects (9 females and 11 males) with untreated Class II malocclusion. Lateral cephalograms were available at the start of treatment (mean age 10 years), end of treatment with functional appliances (mean age 12 years), and long-term observation (mean age 18.6 years). The treated sample also was divided into two groups according to skeletal maturity. The early-treatment group was composed of 20 subjects (12 females and 8 males) treated before puberty, while the late-treatment group included 20 subjects (10 females and 10 males) treated at puberty. Statistical comparisons were performed with analysis of variance followed by Tukey's post hoc tests. Significant long-term mandibular changes (Co-Gn) in the treated group (3.6 mm over the controls) were associated with improvements in the skeletal sagittal intermaxillary relationship, overjet, and molar relationship (∼3.0-3.5 mm). Treatment during the pubertal peak was able to produce significantly greater increases in total mandibular length (4.3 mm) and mandibular ramus height (3.1 mm) associated with a significant advancement of the bony chin (3.9 mm) when compared with treatment before puberty. Treatment of Class II malocclusion with functional appliances appears to be more effective at puberty.

  4. Combined Treatment with Gonadotropin-releasing Hormone Analog and Anabolic Steroid Hormone Increased Pubertal Height Gain and Adult Height in Boys with Early Puberty for Height.

    Science.gov (United States)

    Tanaka, Toshiaki; Naiki, Yasuhiro; Horikawa, Reiko

    2012-04-01

    Twenty-one boys with a height of 135 cm or less at onset of puberty were treated with a combination of GnRH analog and anabolic steroid hormone, and their pubertal height gain and adult height were compared with those of untreated 29 boys who enter puberty below 135 cm. The mean age at the start of treatment with a GnRH analog, leuprorelin acetate depot (Leuplin(®)) was 12.3 yr, a mean of 1.3 yr after the onset of puberty, and GnRH analog was administered every 3 to 5 wk thereafter for a mean duration of 4.1 yr. The anabolic steroid hormone was started approximately 1 yr after initiation of treatment with the GnRH analog. The mean pubertal height gain from onset of puberty till adult height was significantly greater in the combination treatment group (33.9 cm) than in the untreated group (26.4 cm) (ppenis and pubic hair is promoted by the anabolic steroid hormone, no psychosocial problems arose because of delayed puberty. No clinically significant adverse events appeared. Combined treatment with GnRH analog and anabolic steroid hormone significantly increased height gain during puberty and adult height in boys who entered puberty with a short stature, since the period until epiphyseal closure was extended due to deceleration of the bone age maturation by administration of the GnRH analog and the growth rate at this time was maintained by the anabolic steroid hormone.

  5. Short-term lower-body plyometric training improves whole body BMC, bone metabolic markers, and physical fitness in early pubertal male basketball players.

    Science.gov (United States)

    Zribi, Anis; Zouch, Mohamed; Chaari, Hamada; Bouajina, Elyes; Ben Nasr, Hela; Zaouali, Monia; Tabka, Zouhair

    2014-02-01

    The effects of a 9-week lower-body plyometric training program on bone mass, bone markers and physical fitness was examined in 51 early pubertal male basketball players divided randomly into a plyometric group (PG: 25 participants) and a control group (CG: 26 participants). Areal bone mineral density (aBMD), bone mineral content (BMC), and bone area (BA) in the whole body, L2-L4 vertebrae, and in total hip, serum levels of osteocalcin (Oc) and C-terminal telopeptide fragment of Type I collagen (CTx), jump, sprint and power abilities were assessed at baseline and 9 weeks. Group comparisons were done by independent student's t-test between means and analyses of (ANOVA) and covariance (ANCOVA), adjusting for baseline values. PG experienced a significant increase in Oc (p BMC and BA in any measured site, except in whole body BMC of the PG. A positive correlation was observed between percentage increase (Δ%) of physical fitness and those of (Oc) for the PG. In summary, biweekly sessions of lower body plyometric training program were successful for improving whole body BMC, bone formation marker (Oc) and physical fitness in early pubertal male basketball players.

  6. Growth hormone mediates pubertal skeletal development independent of hepatic IGF-1 production.

    Science.gov (United States)

    Courtland, Hayden-William; Sun, Hui; Beth-On, Mordechay; Wu, Yingjie; Elis, Sebastien; Rosen, Clifford J; Yakar, Shoshana

    2011-04-01

    Deficiencies in either growth hormone (GH) or insulin-like growth factor 1 (IGF-1) are associated with reductions in bone size during growth in humans and animal models. Liver-specific IGF-1-deficient (LID) mice, which have 75% reductions in serum IGF-1, were created previously to separate the effects of endocrine (serum) IGF-1 from autocrine/paracrine IGF-1. However, LID mice also have two- to threefold increases in GH, and this may contribute to the observed pubertal skeletal phenotype. To clarify the role of GH in skeletal development under conditions of significantly reduced serum IGF-1 levels (but normal tissue IGF-1 levels), we studied the skeletal response of male LID and control mice to GH inhibition by pegvisomant from 4 to 8 weeks of age. Treatment of LID mice with pegvisomant resulted in significant reductions in body weight, femur length (Le), and femur total area (Tt.Ar), as well as further reductions in serum IGF-1 levels by 8 weeks of age, compared with the mean values of vehicle-treated LID mice. Reductions in both Tt.Ar and Le were proportional after treatment with pegvisomant. On the other hand, the relative amount of cortical tissue formed (RCA) in LID mice treated with pegvisomant was significantly less than that in both vehicle-treated LID and control mice, indicating that antagonizing GH action, either directly (through GH receptor signaling inhibition) or indirectly (through further reductions in serum/tissue IGF-1 levels), results in disproportionate reductions in the amount of cortical bone formed. This resulted in bones with significantly reduced mechanical properties (femoral whole-bone stiffness and work to failure were markedly decreased), suggesting that compensatory increases of GH in states of IGF-1 deficiency (LID mice) act to protect against a severe inhibition of bone modeling during growth, which otherwise would result in bones that are too weak for normal and/or extreme loading conditions. Copyright © 2011 American Society for

  7. Growth trajectory and pubertal tempo from birth till final height in a girl with Wolf-Hirschhorn syndrome.

    Science.gov (United States)

    Siew, Jia Xuan; Yap, Fabian

    2018-01-01

    Growth anomaly is a prominent feature in Wolf-Hirschhorn syndrome (WHS), a rare congenital disorder caused by variable deletion of chromosome 4p. While growth charts have been developed for WHS patients 0-4 years of age and growth data available for Japanese WHS patients 0-17 years, information on pubertal growth and final height among WHS children remain lacking. Growth hormone (GH) therapy has been reported in two GH-sufficient children with WHS, allowing for pre-puberty catch up growth; however, pubertal growth and final height information was also unavailable. We describe the complete growth journey of a GH-sufficient girl with WHS from birth until final height (FH), in relation to her mid parental height (MPH) and target range (TR). Her growth trajectory and pubertal changes during childhood, when she was treated with growth hormone (GH) from 3 years 8 months old till 6 months post-menarche at age 11 years was fully detailed. Pubertal growth characteristics and FH information in WHS is lacking.While pre-pubertal growth may be improved by GH, GH therapy may not translate to improvement in FH in WHS patients.Longitudinal growth, puberty and FH data of more WHS patients may improve the understanding of growth in its various phases (infancy/childhood/puberty).

  8. Time to work or time to play: the effect of student employment on homework, sleep, and screen time

    OpenAIRE

    Kalenkoski, Charlene Marie; Wulff Pabilonia, Sabrina

    2009-01-01

    We use detailed time-diary information on high school students’ daily activities from the 2003–2008 American Time Use Surveys (ATUS) to investigate the effects of employment on the time a student spends on homework and other major activities. Time-diary data are more detailed and accurate than data derived from responses to “usual activity” survey questions underlying other analyses and capture the immediate effects of working that may well accumulate over time to affect future outcomes. Our ...

  9. Perception regarding pubertal changes among rural adolescent boys of Haryana: A school based study

    Directory of Open Access Journals (Sweden)

    Vinod Chayal

    2016-06-01

    Full Text Available Background: Adolescence is a transition phase through which a child matures into an adult. The physical changes in the human body are from infant to child to adolescence to adult to old age.  All phases of life behave like a coin with both good and bad facets attached to each phase of life. Aims & Objectives:  1. To study perception and awareness regarding pubertal changes among school going adolescent boys. 2. To study the association between education and perceived pubertal problems among study subjects. Material & Methods: The study was conducted among male students of senior secondary schools of community development block Beri in one year. The study universe comprised of students in middle and late adolescence (aged 14-18 years studying in 9th to 12th classes of the senior secondary schools in the area. A total of 1000 male students were selected from these schools which were more than the required sample size of 891. Results: The study found that 42.66% students and a half (50% of students of class 9th & 10th and class 11th & 12th respectively considered that pubertal changes as a normal phenomenon. The majority of students admitted practicing masturbation and felt shy and guilty for practicing masturbation, also students felt fatigued after night emission. Conclusions: The study concludes that adolescent’s sexuality which often causes controversy and concern among adults is least discussed with them during adolescence. The reasons for this may be many, including moral grounds or because of concomitant health risks and threats to wellbeing.

  10. Perception regarding pubertal changes among rural adolescent boys of Haryana: A school based study

    Directory of Open Access Journals (Sweden)

    Vinod Chayal

    2016-06-01

    Full Text Available Background: Adolescence is a transition phase through which a child matures into an adult. The physical changes in the human body are from infant to child to adolescence to adult to old age.  All phases of life behave like a coin with both good and bad facets attached to each phase of life. Aims & Objectives:  1. To study perception and awareness regarding pubertal changes among school going adolescent boys. 2. To study the association between education and perceived pubertal problems among study subjects. Material & Methods: The study was conducted among male students of senior secondary schools of community development block Beri in one year. The study universe comprised of students in middle and late adolescence (aged 14-18 years studying in 9th to 12th classes of the senior secondary schools in the area. A total of 1000 male students were selected from these schools which were more than the required sample size of 891. Results: The study found that 42.66% students and a half (50% of students of class 9th & 10th and class 11th & 12th respectively considered that pubertal changes as a normal phenomenon. The majority of students admitted practicing masturbation and felt shy and guilty for practicing masturbation, also students felt fatigued after night emission. Conclusions: The study concludes that adolescent’s sexuality which often causes controversy and concern among adults is least discussed with them during adolescence. The reasons for this may be many, including moral grounds or because of concomitant health risks and threats to wellbeing.

  11. Learning to trust : network effects through time.

    NARCIS (Netherlands)

    Barrera, D.; Bunt, G. van de

    2009-01-01

    This article investigates the effects of information originating from social networks on the development of interpersonal trust relations in the context of a dialysis department of a Dutch medium-sized hospital. Hypotheses on learning effects are developed from existing theories and tested using

  12. Learning to trust: network effects through time

    NARCIS (Netherlands)

    Barrera, D.; van de Bunt, G

    2009-01-01

    This article investigates the effects of information originating from social networks on the development of interpersonal trust relations in the context of a dialysis department of a Dutch medium-sized hospital. Hypotheses on learning effects are developed from existing theories and tested using

  13. Time-aggregation effects on the baseline of continuous-time and discrete-time hazard models

    NARCIS (Netherlands)

    ter Hofstede, F.; Wedel, M.

    In this study we reinvestigate the effect of time-aggregation for discrete- and continuous-time hazard models. We reanalyze the results of a previous Monte Carlo study by ter Hofstede and Wedel (1998), in which the effects of time-aggregation on the parameter estimates of hazard models were

  14. Genital Involvement In Pre-Pubertal Pediatric Population: A Rare Aspect of Crohn’s Disease

    Directory of Open Access Journals (Sweden)

    Qurratul Ann Warsi

    2016-09-01

    Full Text Available Crohn’s disease is an inflammatory bowel disease (IBD, characterized by chronic intestinal inflammation that causes the loss of immune tolerance leading to bizarre inflammatory signals and disruption of mucosal barriers. Environmental triggers and interaction of genetic determinants also play an indispensible role. In this case report, we present a pre-pubertal girl with intermittent and refractory genital swelling. We emphasize that Crohn’s disease must be considered in the differential diagnosis of recurrent, non-tender, erythematous and edematous lesions of the genital area. We conclude with future directions for diagnosing and managing vulvar Crohn’s disease in pediatric population.

  15. Polymorphisms in JMJD1C are associated with pubertal onset in boys and reproductive function in men

    DEFF Research Database (Denmark)

    Mørup, Nina; Busch, Alexander Siegfried; Bang, Anne Kirstine

    2017-01-01

    single nucleotide polymorphisms (SNPs) nearby JMJD1C are associated with pubertal onset in boys and with male reproduction. 671 peri-pubertal boys, 1,027 young men, 315 fertile men, and 252 infertile men were genotyped for two JMJD1C SNPs (rs7910927 and rs10822184). rs7910927 and rs10822184 showed high...... linkage. Boys with the rs7910927 TT genotype entered puberty 3.6 months earlier than their peers (p = 2.5 × 10-2). In young men, the number of T alleles was associated with decreased levels of SHBG, follicle-stimulating hormone (FSH), testosterone, and testosterone x luteinizing hormone, as well...... on the age at pubertal onset in boys as well as levels of reproductive hormones and testis size in men, emphasizing the relationship between JMJD1C and reproductive functions....

  16. Protein profiles of serum, brain regions and hypophyses of pubertal ...

    African Journals Online (AJOL)

    The effects of dietary fumonisin B1 (FB1 ), a toxin produced mainly by Fusarium verticillioides and F. proliferatum that grow on maize worldwide, on protein profiles of serum, brain regions and hypophyses were studied in 24 male Large White weanling pigs randomly divided into four groups (n = 6). In a completely ...

  17. Pubertal Development and Peer Influence on Risky Decision Making

    Science.gov (United States)

    Kretsch, Natalie; Harden, Kathryn Paige

    2014-01-01

    Adolescents engage in more risky behavior when they are with peers and show, on average, heightened susceptibility to peer influence relative to children and adults. However, individual differences in susceptibility to peer influence are not well understood. The current study examined whether the effect of peers on adolescents' risky decision…

  18. Ethanolic extract of Moringa oleifera Lam. leaves protect the pre-pubertal spermatogonial cells from cyclophosphamide-induced damage.

    Science.gov (United States)

    Nayak, Guruprasad; Honguntikar, Sachin D; Kalthur, Sneha Guruprasad; D'Souza, Antony Sylvan; Mutalik, Srinivas; Setty, Manjunath M; Kalyankumar, Raksha; Krishnamurthy, Hanumanthappa; Kalthur, Guruprasad; Adiga, Satish Kumar

    2016-04-22

    Moringa oleifera Lam. is widely cultivated in Asian and African countries for its medicinal and dietary significance. The leaves are highly nutritious and are known to possess various biological activities. Pre-pubertal Swiss albino male mice were injected with single dose of cyclophosphamide (CP, 200mg/kg body weight) or ethanolic extract of Moringa oleifera leaves (MOE, 100mg/kg body weight) intraperitoneally. In combination group, MOE was administered 24h prior to CP injection. CP induced a significant decrease in testicular weight (p<0.01) and depletion of germ cells (p<0.001) and higher level of DNA damage (p<0.001) compared to control. The expression of P53, Bax, Cytochrome C (Cyt C) was increased while there was a decrease in the expression of Bcl2, c-Kit and Oct4. Administration of MOE 24h prior to CP treatment ameliorated the depletion (p<0.001), DNA damage (p<0.001) and apoptosis (p<0.01) of germ cells induced by CP. The mitigating effect of MOE appears to be mediated by up-regulating the expression of c-Kit and Oct4 transcripts in P53-independent manner. MOE protects the spermatogonial cells from CP-induced damage by modulating the apoptotic response elicited by CP and therefore can be considered as an efficient method of male fertility preservation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. Bibliography on dead-time effects

    International Nuclear Information System (INIS)

    1975-01-01

    A BIPM (Bureau International des Poids et Mesures) Working Party has assembled a bibliography of the publications dealing with the measurement of dead times, the evaluation of the corresponding corrections and of other closely related subjects. It contains some 350 references, each of which is given with its full title; an author index is added. The search has been stopped in August 1975

  20. Students' Pressure, Time Management and Effective Learning

    Science.gov (United States)

    Sun, Hechuan; Yang, Xiaolin

    2009-01-01

    Purpose: This paper aims to survey the status quo of the student pressure and the relationship between their daily time management and their learning outcomes in three different types of higher secondary schools at Shenyang, the capital city of Liaoning Province in mainland China. Design/methodology/approach: An investigation was carried out in 14…

  1. EFFECT OF DETARCHMENT TIME OF PINEAPPLE

    African Journals Online (AJOL)

    user

    Journal of Agriculture and Social Research, Vol. 13, No.2 ... crowns were planted in a media consisting of top soil and rice husk on 1:1 volume basis. .... better than those in unshaded fields also, longer storage time depressed number of leaves.

  2. Pubertally born neurons and glia are functionally integrated into limbic and hypothalamic circuits of the male Syrian hamster.

    Science.gov (United States)

    Mohr, Margaret A; Sisk, Cheryl L

    2013-03-19

    During puberty, the brain goes through extensive remodeling, involving the addition of new neurons and glia to brain regions beyond the canonical neurogenic regions (i.e., dentate gyrus and olfactory bulb), including limbic and hypothalamic cell groups associated with sex-typical behavior. Whether these pubertally born cells become functionally integrated into neural circuits remains unknown. To address this question, we gave male Syrian hamsters daily injections of the cell birthdate marker bromodeoxyuridine throughout puberty (postnatal day 28-49). Half of the animals were housed in enriched environments with access to a running wheel to determine whether enrichment increased the survival of pubertally born cells compared with the control environment. At 4 wk after the last BrdU injection, animals were allowed to interact with a receptive female and were then killed 1 h later. Triple-label immunofluorescence for BrdU, the mature neuron marker neuronal nuclear antigen, and the astrocytic marker glial fibrillary acidic protein revealed that a proportion of pubertally born cells in the medial preoptic area, arcuate nucleus, and medial amygdala differentiate into either mature neurons or astrocytes. Double-label immunofluorescence for BrdU and the protein Fos revealed that a subset of pubertally born cells in these regions is activated during sociosexual behavior, indicative of their functional incorporation into neural circuits. Enrichment affected the survival and activation of pubertally born cells in a brain region-specific manner. These results demonstrate that pubertally born cells located outside of the traditional neurogenic regions differentiate into neurons and glia and become functionally incorporated into neural circuits that subserve sex-typical behaviors.

  3. Insulin resistance in obese children and adolescents: HOMA-IR cut-off levels in the prepubertal and pubertal periods.

    Science.gov (United States)

    Kurtoğlu, Selim; Hatipoğlu, Nihal; Mazıcıoğlu, Mümtaz; Kendirici, Mustafa; Keskin, Mehmet; Kondolot, Meda

    2010-01-01

    Childhood obesity is associated with an increased risk for insulin resistance. The underlying mechanism for the physiological increase in insulin levels in puberty is not clearly understood. The aim of the present study was to determine the cut-off values for homeostasis model assessment for insulin resistance (HOMA-IR) in obese children and adolescents according to gender and pubertal status. Two hundred and eight obese children and adolescents (141 girls, 127 boys) aged between 5 and 18 years were included in the study. The children were divided into prepubertal and pubertal groups. A standard oral glucose tolerance test (OGTT) was carried out in all children. A total insulin level exceeding 300 μU/mL in the blood samples, collected during the test period, was taken as the insulin resistance criterion. Cut-off values for HOMA-IR were calculated by receiver operating characteristic (ROC) analysis. In the prepubertal period, the rate of insulin resistance was found to be 37% in boys and 27.8% in girls,while in the pubertal period, this rate was 61.7% in boys and 66.7% in girls. HOMA-IR cut-off values for insulin resistance in the prepubertal period were calculated to be 2.67 (sensitivity 88.2%, specificity 65.5%) in boys and 2.22 (sensitivity 100%, specificity 42.3%) in girls, and in the pubertal period, they were 5.22 (sensitivity 56%, specificity 93.3%) in boys and 3.82 (sensitivity 77.1%, specificity 71.4%) in girls. Since gender, obesity and pubertal status are factors affecting insulin resistance, cut-off values which depend on gender and pubertal status, should be used in evaluation of insulin resistance.

  4. High Times: The Effect of Medical Marijuana Laws on Student Time Use

    OpenAIRE

    Chu, Yu-Wei Luke; Gershenson, Seth

    2016-01-01

    Twenty-three states and the District of Columbia have passed medical marijuana laws. Previous research shows that these laws increase marijuana use among adults. In this paper, we estimate the effects of medical marijuana laws (MML) on secondary and post-secondary students' time use using time diaries from the American Time Use Survey. We apply a difference-in-differences research design and estimate flexible fixed effects models that condition on state fixed effects and state-specific time t...

  5. Impact of socio-emotional context, brain development, and pubertal maturation on adolescent risk-taking.

    Science.gov (United States)

    Smith, Ashley R; Chein, Jason; Steinberg, Laurence

    2013-07-01

    While there is little doubt that risk-taking is generally more prevalent during adolescence than before or after, the underlying causes of this pattern of age differences have long been investigated and debated. One longstanding popular notion is the belief that risky and reckless behavior in adolescence is tied to the hormonal changes of puberty. However, the interactions between pubertal maturation and adolescent decision making remain largely understudied. In the current review, we discuss changes in decision making during adolescence, focusing on the asynchronous development of the affective, reward-focused processing system and the deliberative, reasoned processing system. As discussed, differential maturation in the structure and function of brain systems associated with these systems leaves adolescents particularly vulnerable to socio-emotional influences and risk-taking behaviors. We argue that this asynchrony may be partially linked to pubertal influences on development and specifically on the maturation of the affective, reward-focused processing system. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Interaction of Pubertal Development and Metabolic Control in Adolescents with Type 1 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    M. Plamper

    2017-01-01

    Full Text Available Background. In T1DM, delayed pubertal development and reduced final height are associated with inadequate metabolic control. Objective. To assess whether T1DM affects pubertal growth spurt and whether metabolic control during puberty is gender-related. Methods. Using a large multicentre database, longitudinal data from 1294 patients were analysed. Inclusion criteria: complete records of height and HbA1c from the age of seven to 16 years. Exclusion criteria: other significant chronic diseases and medications, T1DM duration less than three months, and initial BMI 97th percentile. Results. Growth velocity (GV was impaired with a significant reduction of peak GV by 1.2 cm in boys. HbA1c increase during male puberty was lower except for a period of 1.5 years. The highest HbA1c increase in boys coincided with maximum growth spurt. In girls, the highest HbA1c increase was observed during late puberty. Even though there is impaired GV, both sexes reach a height at 16 years of age which corresponds to the background population height. Conclusion. Worsening of metabolic control is sex-discordant and associated with gender-specific alterations of GV. However, the vast majority of boys and girls with T1DM seems to reach normal height at the age of 16 years.

  7. Distributed pubertal growth in girls after acute leukemia: a relative growth hormone insufficiency with late presentation

    Energy Technology Data Exchange (ETDEWEB)

    Moell, C.

    1988-01-01

    Long-term follow-up of growth and development after acute lymphoblastic leukaemia (ALL) in childhood has previously been limited to the prepubertal period. This study describes pubertal growth, final height and the spontaneous secretion of GH in girls treated for ALL, including CNS irradiation with 24 GY. Ten girls, treated earlier for ALL, experienced the menarche at a mean age of 12.2 years. This is significantly earlier than the mean for Swedish girls. Prepubertal growth was near normal after the end of therapy for leukaemia. Mean final height was -1.7 SD, which is 1.5 SD less than at onset and 1.0 SD less than 1 year after the end of treatment. Thirteen other girls had a blunted spontaneous secretion of GH, several years after treatment for ALL; there was no increase in GH secretion during puberty. These results suggest that girls who have been treated for ALL, including CNS irradiation, have a relative GH insufficiency. This insufficiency becomes obvious only when girls cannot respond to the increased need for GH during the pubertal spurt.

  8. Vegetable and Fruit Intakes Are Associated with hs-CRP Levels in Pre-Pubertal Girls

    Directory of Open Access Journals (Sweden)

    Pilar Navarro

    2017-03-01

    Full Text Available The influence of diet on inflammation in children remains unclear. We aimed to analyze the influence of diet on high-sensitivity C-reactive protein (hs-CRP levels in a pre-pubertal population free of other influences that may affect hs-CRP levels. We determined hs-CRP levels in 571 six- to eight-year-old children using an hs-CRP ELISA kit. Information on food and nutrient intake was obtained through a food-frequency questionnaire. Overall dietary quality was assessed using the Healthy Eating Index (HEI. We found that girls in the highest tertile of hs-CRP levels had a higher intake of saturated fatty acid, and lower intakes of fiber and vitamin E and a lower HEI score when compared to those in tertiles 1 and 2. We also observed a significant decrease in fruit and vegetable intakes by hs-CRP tertile. Factor analysis showed that a dietary pattern that was loaded most strongly with vegetable, fruit, fiber and vitamin A and E intakes correlated negatively (−0.132, p < 0.05 with hs-CRP. No such association was found in boys. In conclusion, our data show that girls with a poorer quality diet show higher hs-CRP levels already at a pre-pubertal age.

  9. Distributed pubertal growth in girls after acute leukemia: a relative growth hormone insufficiency with late presentation

    International Nuclear Information System (INIS)

    Moell, C.

    1988-01-01

    Long-term follow-up of growth and development after acute lymphoblastic leukaemia (ALL) in childhood has previously been limited to the prepubertal period. This study describes pubertal growth, final height and the spontaneous secretion of GH in girls treated for ALL, including CNS irradiation with 24 GY. Ten girls, treated earlier for ALL, experienced the menarche at a mean age of 12.2 years. This is significantly earlier than the mean for Swedish girls. Prepubertal growth was near normal after the end of therapy for leukaemia. Mean final height was -1.7 SD, which is 1.5 SD less than at onset and 1.0 SD less than 1 year after the end of treatment. Thirteen other girls had a blunted spontaneous secretion of GH, several years after treatment for ALL; there was no increase in GH secretion during puberty. These results suggest that girls who have been treated for ALL, including CNS irradiation, have a relative GH insufficiency. This insufficiency becomes obvious only when girls cannot respond to the increased need for GH during the pubertal spurt. (author)

  10. Pubertal development, physical self-perception, and motivation toward physical activity in girls.

    Science.gov (United States)

    Labbrozzi, Dina; Robazza, Claudio; Bertollo, Maurizio; Bucci, Ines; Bortoli, Laura

    2013-08-01

    We examined the differences in physical self-perception and motivation toward physical activity in early- and mid-adolescent girls. Body Mass Index (BMI) and pubertal status, assessed by means of the Tanner scale, were collected in 11-year-old (n=74) and 13-year-old girls (n=60). The assessment included six scales from the Physical Self-Description Questionnaire, the Physical Activity Enjoyment Scale, and the Situational Intrinsic Motivation Scale. Age differences emerged, with older girls showing a poorer physical perception and lower scores in intrinsic motivation and enjoyment of physical activity. In the subsample of 11-year-olds, findings showed that more developed girls reported a poorer physical perception on the scales of body fat, global physical self-concept, and appearance, and a lower score in the PACES positive scale. Results underscore the need to promote interventions aimed at encouraging active lifestyles among children and adolescent girls, in order to prevent overweight prior to pubertal onset. Copyright © 2013 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  11. Parental attitudes to pre-pubertal HPV vaccination.

    Science.gov (United States)

    Marlow, Laura A V; Waller, Jo; Wardle, Jane

    2007-03-01

    To determine the acceptability of childhood HPV vaccination and examine demographic, cultural, and psychosocial predictors of vaccine acceptance. School-based survey. Questionnaires sent to 1205 mothers of 8-14-year-old girls. Responses from 684 were included in the analyses. Ten schools (seven primary, three secondary) in four areas of England. Seventy-five percent of mothers would accept the vaccine for their daughter. Vaccine acceptance was higher in mothers who had experience of cancer in the family (OR=1.61, CI: 1.14-2.29), had older daughters (OR=1.15, CI: 1.04-1.27), perceived approval from husband/partner (OR=14.51, CI: 6.15-34.25) and believed vaccine acceptance would be more normative (OR=1.78, CI: 1.59-2.01). Having concerns about too many vaccinations (OR=0.22, CI: 0.15-0.31) or vaccine side effects (OR=0.37, CI: 0.28-0.50) and worry about increasing promiscuity (OR=0.47, CI: 0.36-0.62) emerged as deterrents. The modal preferred age was 12 years. Endorsing vaccination at earlier ages was predicted by feeling able to discuss related topics, including sex, at younger ages (OR=1.37, CI: 1.24-1.51) and concern about increasing promiscuity (OR=0.61, CI: 0.47-0.78). Overall, there was a favourable response to HPV vaccination. Emphasising the widespread acceptance of the vaccine might promote acceptance further, as would information on immunological and social benefits of earlier vaccination.

  12. Percentiles of fasting serum insulin, glucose, HbA1c and HOMA-IR in pre-pubertal normal weight European children from the IDEFICS cohort.

    Science.gov (United States)

    Peplies, J; Jiménez-Pavón, D; Savva, S C; Buck, C; Günther, K; Fraterman, A; Russo, P; Iacoviello, L; Veidebaum, T; Tornaritis, M; De Henauw, S; Mårild, S; Molnár, D; Moreno, L A; Ahrens, W

    2014-09-01

    The aim of this study is to present age- and sex-specific reference values of insulin, glucose, glycosylated haemoglobin (HbA1c) and the homeostasis model assessment to quantify insulin resistance (HOMA-IR) for pre-pubertal children. The reference population consists of 7074 normal weight 3- to 10.9-year-old pre-pubertal children from eight European countries who participated in at least one wave of the IDEFICS ('identification and prevention of dietary- and lifestyle-induced health effects in children and infants') surveys (2007-2010) and for whom standardised laboratory measurements were obtained. Percentile curves of insulin (measured by an electrochemiluminescence immunoassay), glucose, HbA1c and HOMA-IR were calculated as a function of age stratified by sex using the general additive model for location scale and shape (GAMLSS) method. Levels of insulin, fasting glucose and HOMA-IR continuously show an increasing trend with age, whereas HbA1c shows an upward trend only beyond the age of 8 years. Insulin and HOMA-IR values are higher in girls of all age groups, whereas glucose values are slightly higher in boys. Median serum levels of insulin range from 17.4 and 13.2 pmol l(-1) in 3-HOMA-IR, median values range from 0.5 and 0.4 in 3-<3.5-year-old girls and boys to 1.7 and 1.4 in 10.5-<11-year-old girls and boys, respectively. Our study provides the first standardised reference values for an international European children's population and provides the, up to now, largest data set of healthy pre-pubertal children to model reference percentiles for markers of insulin resistance. Our cohort shows higher values of Hb1Ac as compared with a single Swedish study while our percentiles for the other glucose metabolic markers are in good accordance with previous studies.

  13. Carbamazepine-exposure during gestation and lactation affects pubertal onset and spermatic parameters in male pubertal offspring.

    Science.gov (United States)

    Andretta, Rhayza Roberta; Okada, Fatima Kazue; Paccola, Camila Cicconi; Stumpp, Taiza; de Oliva, Samara Urban; Miraglia, Sandra M

    2014-04-01

    Carbamazepine (CBZ) is an anti-epileptic drug that acts on Leydig cells, affecting steroidogenesis and causes fetal malformation. The aim of this study was to investigate the effects of CBZ on male sexual maturation and other male parameters. Rat dams were treated with CBZ during pregnancy and breastfeeding. The anogenital distance (AGD) and the anogenital index (AGI) were obtained. Testicular descent and preputial separation were also evaluated. The offspring was euthanized at PND 41 and 63. The accessory glands were weighed and the testes were collected for histopathological, morphometric and sterological analyses. The numerical density of Leydig cells and hormone dosage were obtained. CBZ caused an increase of AGI and a delay of testicular descent and of preputial separation. CBZ also caused a decrease of testosterone level and of sperm count and an increase of abnormal sperm. These results indicate that CBZ delays puberty onset and affects steroidogenesis and sperm quality. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Evaluation of apoptotic- and autophagic-related protein expressions before and after IVM of fresh, slow-frozen and vitrified pre-pubertal mouse testicular tissue.

    Science.gov (United States)

    Dumont, L; Chalmel, F; Oblette, A; Berby, B; Rives, A; Duchesne, V; Rondanino, C; Rives, N

    2017-11-01

    Do freezing and in vitro culture procedures enhance the expression of proteins involved in apoptotic or autophagic pathways in murine pre-pubertal testicular tissue? IVM strongly modified apoptosis- and autophagy-related relative protein levels in mice testicular tissue whereas the impact of cryopreservation procedures was minimal at the end of the culture. In vitro spermatogenesis remains a challenging technical issue as it imposes to find a very close balance between survival and death of germ cell natural precursors (i.e. gonocytes and spermatogonia), which will eventually undergo a complete spermatogenesis close to in vivo conditions. The establishment of efficient culture conditions coupled with suitable cryopreservation procedures (e.g. controlled slow freezing [CSF] and solid surface vitrification [SSV]) of pre-pubertal testicular tissue is a crucial step in the fields of fertility preservation and restoration to improve the spermatic yield obtained in vitro. Here, we study cryopreservation procedures (i.e. CSF or SSV) and the impact of culture media compositions. A first set of 66 mouse pre-pubertal testes were directly cultured during 30, 36, 38 and 60 days (D) from 2.5 to 6.5-day-old CD-1 mice to evaluate the impact of time-aspect of culture and to endorse the reverse phase protein microarrays (RPPM) technique as an adapted experimental tool for the field of in vitro spermatogenesis. Ninety others fresh, slow-frozen and vitrified pre-pubertal testes were cultured during 30 days for the principal study to evaluate the impact of cryopreservation procedures before and after culture. Thirty-four testes dissected from 2.5, 6.5, 36.5, 40.5, 42.5 and 62.5 days postpartum (dpp) mice, corresponding to the time frames of spermatogenesis orchestrated in vitro, were used as in vivo controls. After in vitro culture, testicular tissue samples originated from 2.5 or 6.5-day-old CD-1 male mice were analyzed using RPPM. This targeted proteomic technique allowed us to

  15. Early Pubertal Maturation and Internalizing Problems in Adolescence: Sex Differences in the Role of Cortisol Reactivity to Interpersonal Stress

    Science.gov (United States)

    Natsuaki, Misaki N.; Klimes-Dougan, Bonnie; Ge, Xiaojia; Shirtcliff, Elizabeth A.; Hastings, Paul D.; Zahn-Waxler, Carolyn

    2009-01-01

    An accumulating body of literature has shown a link between early pubertal maturation and internalizing problems, particularly among girls. Our knowledge is, however, limited with regard to what accounts for this association. Based on a hypothesis that early maturing girls have heightened stress sensitivity that increases the risk of internalizing…

  16. The reliability of dental x-ray film in assessment of MP3 stages of the pubertal growth spurt.

    Science.gov (United States)

    Abdel-Kader, H M

    1998-10-01

    The main object of this clinical study is to provide a simple and practical method to assess the pubertal growth spurt stages of a subject by recording MP3 stages with the dental periapical radiograph and the standard dental x-ray machine.

  17. Relationships of Pubertal Development among Early Adolescents to Sexual and Nonsexual Risk Behaviors and Caregivers' Parenting Behaviors

    Science.gov (United States)

    Koo, Helen P.; Rose, Allison; Bhaskar, Brinda; Walker, Leslie R.

    2012-01-01

    Using a school-based sample of fifth graders (mean age = 10.38, SD = 0.66) and their parents (N = 408) from Washington, D.C., the authors examine associations of pubertal development with early adolescents' sexual and nonsexual risk behaviors and their caregivers' parenting behaviors and of these risk behaviors with parenting behaviors. Results…

  18. Sex-specific mouse liver gene expression: genome-wide analysis of developmental changes from pre-pubertal period to young adulthood

    Directory of Open Access Journals (Sweden)

    Conforto Tara L

    2012-04-01

    Full Text Available Abstract Background Early liver development and the transcriptional transitions during hepatogenesis are well characterized. However, gene expression changes during the late postnatal/pre-pubertal to young adulthood period are less well understood, especially with regards to sex-specific gene expression. Methods Microarray analysis of male and female mouse liver was carried out at 3, 4, and 8 wk of age to elucidate developmental changes in gene expression from the late postnatal/pre-pubertal period to young adulthood. Results A large number of sex-biased and sex-independent genes showed significant changes during this developmental period. Notably, sex-independent genes involved in cell cycle, chromosome condensation, and DNA replication were down regulated from 3 wk to 8 wk, while genes associated with metal ion binding, ion transport and kinase activity were up regulated. A majority of genes showing sex differential expression in adult liver did not display sex differences prior to puberty, at which time extensive changes in sex-specific gene expression were seen, primarily in males. Thus, in male liver, 76% of male-specific genes were up regulated and 47% of female-specific genes were down regulated from 3 to 8 wk of age, whereas in female liver 67% of sex-specific genes showed no significant change in expression. In both sexes, genes up regulated from 3 to 8 wk were significantly enriched (p p Ihh; female-specific Cdx4, Cux2, Tox, and Trim24 and may contribute to the developmental changes that lead to global acquisition of liver sex-specificity by 8 wk of age. Conclusions Overall, the observed changes in gene expression during postnatal liver development reflect the deceleration of liver growth and the induction of specialized liver functions, with widespread changes in sex-specific gene expression primarily occurring in male liver.

  19. Associations of Birth Order with Early Adolescent Growth, Pubertal Onset, Blood Pressure and Size: Evidence from Hong Kong's "Children of 1997" Birth Cohort.

    Directory of Open Access Journals (Sweden)

    Man Ki Kwok

    Full Text Available Birth order has been proposed as a cardiovascular risk factor, because the lower birth weight and greater infant weight gain typical of firstborns could programme metabolism detrimentally.We examined the associations of birth order (firstborn or laterborn with birth weight-for-gestational age, length/height and body mass index (BMI z-scores during infancy, childhood, and puberty using generalized estimating equations, with age at pubertal onset using interval-censored regression and with age-, sex- and height-standardized blood pressure, height and BMI z-scores at 13 years using linear regression in a population-representative Chinese birth cohort: "Children of 1997" (n = 8,327.Compared with laterborns, firstborns had lower birth weight-for-gestational age (mean difference = -0.18 z-score, 95% confidence interval (CI -0.23, -0.14, lower infant BMI (-0.09 z-score, 95% CI -0.14, -0.04, greater childhood height (0.10 z-score, 95% CI 0.05, 0.14 and BMI (0.08 z-score, 95% CI 0.03, 0.14, but not greater pubertal BMI (0.05 z-score, 95% CI -0.02, 0.11, adjusted for sex, parental age, birthplace, education and income. Firstborns had earlier onset of pubic hair (time ratio = 0.988, 95% CI 0.980, 0.996, but not breast or genitalia, development. Firstborns had greater BMI (0.07 z-score, 95% CI 0.002, 0.15, but not height (0.05 z-score, 95% CI -0.01, 0.11, at 13 years, but similar blood pressure.Differences by birth order continue into early adolescence with firstborns being heavier with earlier pubic hair development, which could indicate long-term cardiovascular risk.

  20. Associations of Birth Order with Early Adolescent Growth, Pubertal Onset, Blood Pressure and Size: Evidence from Hong Kong's "Children of 1997" Birth Cohort.

    Science.gov (United States)

    Kwok, Man Ki; Leung, Gabriel M; Schooling, C Mary

    2016-01-01

    Birth order has been proposed as a cardiovascular risk factor, because the lower birth weight and greater infant weight gain typical of firstborns could programme metabolism detrimentally. We examined the associations of birth order (firstborn or laterborn) with birth weight-for-gestational age, length/height and body mass index (BMI) z-scores during infancy, childhood, and puberty using generalized estimating equations, with age at pubertal onset using interval-censored regression and with age-, sex- and height-standardized blood pressure, height and BMI z-scores at 13 years using linear regression in a population-representative Chinese birth cohort: "Children of 1997" (n = 8,327). Compared with laterborns, firstborns had lower birth weight-for-gestational age (mean difference = -0.18 z-score, 95% confidence interval (CI) -0.23, -0.14), lower infant BMI (-0.09 z-score, 95% CI -0.14, -0.04), greater childhood height (0.10 z-score, 95% CI 0.05, 0.14) and BMI (0.08 z-score, 95% CI 0.03, 0.14), but not greater pubertal BMI (0.05 z-score, 95% CI -0.02, 0.11), adjusted for sex, parental age, birthplace, education and income. Firstborns had earlier onset of pubic hair (time ratio = 0.988, 95% CI 0.980, 0.996), but not breast or genitalia, development. Firstborns had greater BMI (0.07 z-score, 95% CI 0.002, 0.15), but not height (0.05 z-score, 95% CI -0.01, 0.11), at 13 years, but similar blood pressure. Differences by birth order continue into early adolescence with firstborns being heavier with earlier pubic hair development, which could indicate long-term cardiovascular risk.

  1. Pubertal Development and Prepubertal Height and Weight Jointly Predict Young Adult Height and Body Mass Index in a Prospective Study in South Africa.

    Science.gov (United States)

    Stein, Aryeh D; Lundeen, Elizabeth A; Martorell, Reynaldo; Suchdev, Parminder S; Mehta, Neil K; Richter, Linda M; Norris, Shane A

    2016-07-01

    Height and adiposity track over childhood, but few studies, to our knowledge, have longitudinally examined the mediating relation of the timing and progression of puberty. We assessed interrelations between prepubertal height and body mass index, the progression through puberty, and young adult height and adiposity. We analyzed data from the Birth to Twenty Plus study (females, n = 823; males, n = 765). Serial measures of anthropometry and pubertal development were obtained between ages 9 and 16 y. We used latent class growth analysis to categorize pubertal development with respect to pubic hair (females and males), breasts (females), and genitalia (males) development. Adult height and weight were obtained at ages 18 to 20 y. Among females, higher latent class (earlier initiation and faster progression through puberty) was associated with an increased risk of obesity [pubic hair class 3 compared with class 1: RR, 3.41 (95% CI: 1.57, 7.44)] and inconsistent associations with height. Among males, higher latent class was associated with increased adult height [pubic hair development class 3 compared with class 1: 2.43 cm (95% CI: 0.88, 4.00)] and increased risk of overweight/obesity [pubic hair development class 3 compared with class 1: OR, 3.44 (95% CI: 1.44, 8.20)]. In females, the association with adult height became inverse after adjusting for prepubertal height [pubic hair development class 3 compared with class 1: females, -1.31 cm (95% CI: -2.32, -0.31)]; in males, the association with height was attenuated with this adjustment [-0.56 cm (95% CI: -1.63, 0.52)]. Associations with adiposity were attenuated after adjusting for prepubertal adiposity. Progression through puberty modifies the relation between prepubertal and adult anthropometry. Screening for early or rapid progression of puberty might identify children at an increased risk of becoming overweight or obese adults.

  2. Dead time effects in laser Doppler anemometry measurements

    DEFF Research Database (Denmark)

    Velte, Clara Marika; Buchhave, Preben; George, William K.

    2014-01-01

    frequency range, starting around the cutoff frequency due to the finite size of the MV. Using computer-generated data mimicking the LDA data, these effects have previously been shown to appear due to the effect of dead time, i.e., the finite time during which the system is not able to acquire new...... measurements. These dead times can be traced back to the fact that the burst-mode LDA cannot measure more than one signal burst at a time. Since the dead time is approximately equal to the residence time for a particle traversing a measurement volume, we are dealing with widely varying dead times, which...

  3. Time management: an imperative factor to effective service delivery ...

    African Journals Online (AJOL)

    In Nigeria, the need for time management in organizations especially the public ... of time management that can lead to employee effectiveness and efficiency in the ... time audit in their work place, be prepared to adjust to the best use of time.

  4. Prediction of basal metabolic rate in obese children and adolescents considering pubertal stages and anthropometric characteristics or body composition.

    Science.gov (United States)

    Lazzer, S; Patrizi, A; De Col, A; Saezza, A; Sartorio, A

    2014-06-01

    To develop and crossvalidate new equations for predicting basal metabolic rate (BMR) in obese children and adolescents in relation to pubertal stages, anthropometric characteristics or body composition. A total of 1696 obese Caucasian children and adolescents (mean body mass index z-score: 3.5±0.8) participated in this study. BMR was determined by indirect calorimetry and fat-free mass (FFM) and fat mass (FM) by bioelectrical impedance analysis. Equations were derived by stepwise multiple regression analysis using a calibration cohort of 848 subjects, and the equations were crossvalidated with a Bland and Altman method in the remaining 848 subjects. Two new specific equations based on gender (1: males; 0: females), pubertal stages (from 1 to 5, assessed according Marshall & Tanner methods) and body weight (BW, kg), stature (m) or body composition (kg) were generated as follows: (1) BMR=(BW × 0.044)+(stature × 2.836)-(pubertal stage × 0.148)+(gender × 0.781)-0.551 (adjusted coefficient of determination (R(2)adj)= 0.69 and root mean squared error (RMSE)=0.954 MJ); (2) BMR=(FFM × 0.082)+(FM × 0.037)-(pubertal stage × 0.125)+(gender × 0.706)+2.528 (R(2)adj= 0.70 and RMSE=0.943 MJ). In the crossvalidation group, mean-predicted BMR was not significantly different from the mean-measured BMR (MBMR) for all children and adolescents, as well as for boys and girls (differenceBMR was predicted accurately (90-110% of MBMR) in 67% of subjects. The new prediction equations considering the pubertal stages allow an accurate and more appropriate (vs equations using chronological age) estimation of BMR in obese children and adolescents.

  5. Essential time management how to become more productive and effective

    CERN Document Server

    Hilder, Brett

    2011-01-01

    Time is a resource like any other. Using your time effectively can transform your personal productivity and determine your level of success. Moreover, it can change your level of job satisfaction and confidence.

  6. Diversity of activity participation determines bone mineral content in the lower limbs of pre-pubertal children with developmental coordination disorder.

    Science.gov (United States)

    Fong, S S M; Vackova, D; Choi, A W M; Cheng, Y T Y; Yam, T T T; Guo, X

    2018-04-01

    This study examined the relationships between activity participation and bone mineralization in children with developmental coordination disorder. Limited participation in physical, recreational, social, and skill-based and self-improvement activities contributed to lower bone mineral content. For improved bone health, these children should participate in a variety of activities, not only physical activities. Limited activity participation in children with developmental coordination disorder (DCD) may have a negative impact on bone mineral accrual. The objectives of this study were to compare bone mineralization and activity participation patterns of pre-pubertal children with DCD and those with typical development, and to determine the association between activity participation patterns and bone mineralization in children with DCD. Fifty-two children with DCD (mean age = 7.51 years) and 61 children with typical development (mean age = 7.22 years) participated in the study. Appendicular and total body (less head) bone mineral content (BMC) and bone mineral density (BMD) were evaluated by a whole-body dual-energy X-ray absorptiometry scan. Activity participation patterns were assessed using the Children's Assessment of Participation and Enjoyment (CAPE) questionnaire. Children with DCD had lower appendicular and total body BMCs and BMDs than children with typical development overall (p accounting for the effects of age, sex, height, lean mass, and fat mass, the total activity diversity score remained independently associated with leg BMC in children with DCD, explaining 5.1% of the variance (p = 0.030). However, the physical activity diversity score was no longer associated with leg BMC (p = 0.090). Diversity of activity participation and bone mineralization were lower in pre-pubertal children with DCD. Decreased total activity participation diversity was a contributing factor to lower BMC in the legs of children with DCD.

  7. The effects of Aloe vera [gel] on clotting time, prothrombin time and ...

    African Journals Online (AJOL)

    Background: Published reports on the effects of Aloe vera gel on blood coagulation in experimental animals are relatively scanty. Aim: To determine the effect of Aloe vera gel on clotting time, prothrombin time and plasma fibrinogen concentration in albino Wistar rats. Methods: A total of 28 adult albino Wistar rats divided ...

  8. Effect of counting system dead time on thyroid uptake measurements

    International Nuclear Information System (INIS)

    Simpkin, D.J.

    1984-01-01

    Equations are derived and the results of numerical calculations shown that illustrate the effect of counting system dead time on measured thyroid uptake of radioiodine. It is predicted that the observed uptake is higher than the true uptake due to system dead time. This is shown for both paralyzing and nonparalyzing dead time. The effect of increasing the administered activity is shown to increase the measured uptake, in a manner predicted by the paralyzable and nonparalyzable dead time models

  9. Phthalate and bisphenol A exposure during in utero windows of susceptibility in relation to reproductive hormones and pubertal development in girls.

    Science.gov (United States)

    Watkins, Deborah J; Sánchez, Brisa N; Téllez-Rojo, Martha Maria; Lee, Joyce M; Mercado-García, Adriana; Blank-Goldenberg, Clara; Peterson, Karen E; Meeker, John D

    2017-11-01

    Over the past several decades, the age of pubertal onset in girls has shifted downward worldwide. As early pubertal onset is associated with increased risky behavior and psychological issues during adolescence and cardiometabolic disease and cancer in adulthood, this is an important public health concern. Exposure to endocrine disrupting chemicals during critical windows of in utero development may play a role in this trend. Our objective was to investigate trimester-specific phthalate and BPA exposure in relation to pubertal development among girls in the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) birth cohort. We measured maternal urinary phthalate metabolites and BPA in samples collected during the first, second, and third trimesters of pregnancy. To assess reproductive development among their female children, we measured serum testosterone, estradiol, dehydroepiandrosterone sulfate (DHEA-S), inhibin B, and sex hormone-binding globulin (SHBG), and assessed sexual maturation, including Tanner staging for breast and pubic hair development and menarche status, at age 8-13 years (n = 120). We used linear and logistic regression to examine measures of trimester-specific in utero exposure as predictors of peripubertal hormone levels and pubertal onset, respectively. In secondary analyses, we evaluated estimated exposure at the midpoint of the first trimester and rates of change in exposure across pregnancy in relation to outcomes. Several phthalate metabolites measured throughout in utero development were associated with higher serum testosterone concentrations, while a number of metabolites measured in the third trimester were associated with higher DHEA-S. For example, an interquartile range (IQR) increase in mean monoethyl phthalate (MEP) levels across pregnancy was associated with 44% higher peripubertal testosterone (95% CI: 13-83%), while an IQR increase in di-2-ethylhexyl phthalate metabolites (ΣDEHP) specifically in the third trimester

  10. Trends in puberty timing in humans and environmental modifiers

    DEFF Research Database (Denmark)

    Toppari, Jorma; Juul, Anders

    2010-01-01

    Secular trends in timing of puberty appear to continue although under-nutrition has not been any longer a limiting factor for pubertal development. Now obesity and other environmental reasons have been suspected to cause this trend, and endocrine disrupting chemicals have become into focus...... as possible contributors. Epidemiological studies on endocrine disrupters are still scarce and show only weak associations between exposures and timing of puberty. Since genetic background explains 50-80% of variability in the timing of puberty, it is not surprising that the observed environmental effects...... are rather modest when individual exposures are assessed. Despite that, some exposures have been reported to be associated to early (e.g., polybrominated biphenyls) or delayed (e.g., lead) puberty. Here we shortly review the available data on recent trends in timing of puberty and the possible role...

  11. Androgenetic Alopecia: A Chronic or Pubertal Onset Disease Retarded by Blood Donation

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Dayer

    2017-09-01

    Full Text Available Background Androgenetic alopecia is the main cause of hair loss and common baldness that affects psychological more than physiological aspects of people’s lives. Studies have shown that this multi factorial disorder is initiated by androgens secretion in pubertal period, minerals limitations, autoimmunity, mental stress, genetic predisposition and some alterations in hematological factors. Objectives The aim of this study was to evaluate the involvement of hematologic parameters in this disease using a case control study design. Methods In this case-controlled study, two groups each of 80 individuals with androgenetic alopecia were voluntarily included in the study based on their medical histories and clinical examinations and subjected to blood tests for routine hematological parameters. The results were then compared and analyzed using SPSS version 16.0. Results Our findings indicated that all the parameters for both groups fall in normal ranges (Mean ± SD but the values for RBC, HGB, MCH, MCHC, WBC, LYM and TIBC were significantly higher in patients than in normal group. The average counts of PLT was significantly lower in patients compared with the normal group. Otherwise, Person’s tests for statistical correlations between two groups indicated that the pattern of correlations were abnormal in patients. Conclusions Our findings indicated the presence of a chronic, immunologic and slowly progressing disorder that causes hair loss, the disease which is in turn triggered in pubertal period upon androgen secretion. We suggest, therefore, that the conditions may be ameliorated by prescription of iron tablet, platelet transfusion and anti-inflammation therapy.

  12. Mental Health Problems of Iranian Female Adolescents and Its Association with Pubertal Development: A Nationwide Study

    Directory of Open Access Journals (Sweden)

    Aria Sotoudeh

    2012-03-01

    Full Text Available Mental health problems including emotional and behavioral problems during puberty may be under influence of different risk factors including cultures, living in urban or rural areas and ethnic factors which may vary between different countries. The main aim of this study is to investigate the profile of emotional and behavioral problems and the role of factors such as age, stage of puberty, ethnicity, rurality and living in urban area, as risk factors in Iranian girls. As a part of a large national study we evaluated the emotional and behavioral problems in different stages of puberty in a community sample of Iranian adolescent girls from public schools that were selected by clustered random sampling method. In all subjects, demographic characteristics, and pubertal stages were measured. Emotional and behavioral problems were evaluated using Strength and Difficulties Questionnaire (SDQ. The associations of age, pubertal development indices, socioeconomic and demographic factors with the behavioral problems were assessed. A total number of 4576 students enrolled the study and responded to the questions. The mean age of participants was 13.83 2.19 years. The mean total score of difficulties in participants was 14.34 5.81. According to these results 813 (17.8% adolescents had total problem scores higher than Goodmans cutoff points and the most frequent problem domain was conduct problems (20.5%. According to the results the most related variable with the total difficulty score of SDQ were ethnicity, residency in urban areas and development of menstrual cycle respectively. The results of this study showed that the most correlated factors with mental health problems in Iranian girls during puberty are ethnicity, urbanity and development of menstrual cycle.

  13. Modulation of mammary gland development in pre-pubertal mice as affected by soya and milk protein supplements.

    Science.gov (United States)

    Alston-Mills, Brenda; Lepri, J J; Martin, C A

    2011-08-01

    The objective of the present study was to determine the effects of soya and whey milk protein, α-lactalbumin (α-LA), on mammary gland morphology and the structural support of the gland, in pre-pubertal mice after 7 d of treatment. In Expt 1, weaned (day 21) CD1 mice were given one of the four treatments, three included dietary supplements: (1) control diet, casein, (2) soya, (3) α-LA and (4) subcutaneous injection of 2·5 μg oestradiol benzoate in 20 μl maize oil and fed the control diet. All diets were isoenergetic with equal protein concentrations. All groups that were not treated with oestradiol received the vehicle. Whole-mount analyses were performed to determine longitudinal ductal growth and terminal end bud development. DNA was extracted from the gland and assessed by spectrophotometry (260/280 nm). Tissue extracts for extracellular matrix (ECM) proteins, matrix metalloproteinase-2 (MMP(2)), tissue inhibitor of MMP(2) (TIMP(2)), and serum oestradiol and mammary tissue epidermal growth factors (EGF) were measured by immunoassays. Expt 2 utilised the Her2/neu transgenic strain, with the same protocols. Statistical significance was determined by one-way ANOVA. From Expt 1 and 2, soya and α-LA significantly increased ductal elongation when compared with the oestrogen and control groups. These results were corroborated by data on total DNA and the ratio of MMP(2):TIMP(2). The ratio of MMP(2):TIMP(2) was affected by α-LA. Serum oestradiol was decreased only in the oestradiol-treated groups in both experiments. Soya is known to be oestrogenic and can act on epithelia directly. The mechanism by which α-LA affects glandular development is by modulating the ECM or by promoting the synthesis/activity of EGF.

  14. Time to Work or Time to Play: The Effect of Student Employment on Homework, Housework, Screen Time, and Sleep

    OpenAIRE

    Sabrina Wulff Pabilonia; Charlene Marie Kalenkoski

    2009-01-01

    Recent research suggests that working while in high school reduces the amount of time students spend doing homework. However, an additional hour of work leads to a reduction in homework by much less than one hour, suggesting a reduction in other activities. This paper uses data from the 2003-2007 American Time Use Surveys (ATUS) to investigate the effects of market work on the time students spend on homework, sleeping, household work, and screen time. Results show that an increase in paid wor...

  15. Effectiveness of firefly algorithm based neural network in time series ...

    African Journals Online (AJOL)

    Effectiveness of firefly algorithm based neural network in time series forecasting. ... In the experiments, three well known time series were used to evaluate the performance. Results obtained were compared with ... Keywords: Time series, Artificial Neural Network, Firefly Algorithm, Particle Swarm Optimization, Overfitting ...

  16. The Effects of Immigration on NHS Waiting Times

    OpenAIRE

    Giuntella, Osea; Nicodemo, Catia; Vargas-Silva, Carlos

    2015-01-01

    This paper analyses the effects of immigration on waiting times in the National Health Service (NHS) in England. Linking administrative records from the Hospital Episode Statistics (2003-2012) with immigration data drawn from the UK Labour Force Survey, we find that immigration reduced waiting times for outpatient referrals and did not have significant effects on waiting times in Accident and Emergency (A&E) and elective care. These results are explained by the fact that immigration increases...

  17. Effects of computing time delay on real-time control systems

    Science.gov (United States)

    Shin, Kang G.; Cui, Xianzhong

    1988-01-01

    The reliability of a real-time digital control system depends not only on the reliability of the hardware and software used, but also on the speed in executing control algorithms. The latter is due to the negative effects of computing time delay on control system performance. For a given sampling interval, the effects of computing time delay are classified into the delay problem and the loss problem. Analysis of these two problems is presented as a means of evaluating real-time control systems. As an example, both the self-tuning predicted (STP) control and Proportional-Integral-Derivative (PID) control are applied to the problem of tracking robot trajectories, and their respective effects of computing time delay on control performance are comparatively evaluated. For this example, the STP (PID) controller is shown to outperform the PID (STP) controller in coping with the delay (loss) problem.

  18. On the time-dependent Aharonov–Bohm effect

    Directory of Open Access Journals (Sweden)

    Jian Jing

    2017-11-01

    Full Text Available The Aharonov–Bohm effect in the background of a time-dependent vector potential is re-examined for both non-relativistic and relativistic cases. Based on the solutions to the Schrodinger and Dirac equations which contain the time-dependent magnetic vector potential, we find that contrary to the conclusions in a recent paper (Singleton and Vagenas 2013 [4], the interference pattern will be altered with respect to time because of the time-dependent vector potential.

  19. Principal Time Management Skills: Explaining Patterns in Principals' Time Use, Job Stress, and Perceived Effectiveness

    Science.gov (United States)

    Grissom, Jason A.; Loeb, Susanna; Mitani, Hajime

    2015-01-01

    Purpose: Time demands faced by school principals make principals' work increasingly difficult. Research outside education suggests that effective time management skills may help principals meet job demands, reduce job stress, and improve their performance. The purpose of this paper is to investigate these hypotheses. Design/methodology/approach:…

  20. The Effectiveness of Time Management Strategies Instruction on Students' Academic Time Management and Academic Self Efficacy

    Science.gov (United States)

    Kader, Fathi Abdul Hamid Abdul; Eissa, Mourad Ali

    2015-01-01

    This study investigated the effect of using time management strategies instruction on improving first year learning disabled students' academic time management and academic self efficacy. A total of 60 students identified with LD participated. The sample was divided into two groups; experimental (n = 30 boys) and control (n = 30 boys). ANCOVA and…

  1. Two Effective Ways to Implement Wait Time. A Symposium on Wait Time.

    Science.gov (United States)

    Swift, J. Nathan; And Others

    The effects of instructional guides and a wait time feedback device (called a "Wait Timer") on the classroom interaction of middle school science teachers are examined. The Wait Timer, an unobtrusive indicator of wait time, is an automatic device that activates a light when a person speaks. The duration of the light at the end of a…

  2. The Effect of Police Response Time on Crime Clearance Rates

    DEFF Research Database (Denmark)

    Blanes i Vidal, Jordi; Kirchmaier, Tom

    2018-01-01

    significant effects: in our preferred estimate, a 10% increase in response time leads to a 4.7 percentage points decrease in the likelihood of clearing the crime. We find stronger effects for thefts than for violent offenses, although the effects are large for every type of crime. We find suggestive evidence...

  3. The effects of maxillary protraction and its long-term stability--a clinical trial in Chinese adolescents.

    Science.gov (United States)

    Chen, LinLing; Chen, RongJing; Yang, YiMing; Ji, GuoPing; Shen, Gang

    2012-02-01

    The purpose of this study was to evaluate the effect of reverse pull headgear (RPHG) in the treatment of Class III malocclusions in the late mixed and early permanent dentition and its long-term stability at the time when facial growth was close to completion. The treatment group comprised 22 subjects (12 males and 10 females, mean age: 11.38 ± 0.69 years). The control group included 17 subjects (7 males and 10 females, mean age: 11.54 ± 1.07 years). The mean RPHG treatment time was 1.5 ± 0.95 years and the observation time for the control group was 1.75 ± 0.83 years. For each subject, lateral cephalograms were obtained before (T1) and after (T2) treatment or observation. These cephalograms were traced and analyzed and the differences between T1 and T2 values were examined with paired t-tests. Of the 22 treated cases, 10 patients were followed up until at the mean age of 16.18 years (T3). Since there was no relapse in anterior crossbite, the long-term effects of RPHG were evaluated by measuring the maxillary and mandibular skeletal changes. The follow-up patients were divided into two groups based on the change in ANB: a stable group (decrease in ANB 2 degrees). The skeletal effects of RPHG in treating Class III anomalies just before or at the beginning of the pubertal growth spurt include protraction of the maxilla and dentition and inhibition of forward growth of the mandible. With regard to the long-term change, a slight alteration in the position of the maxilla and in the position and growth direction of the mandible resulted in a slight decrease in ANB in the stable group. The slight retrusion in the maxilla, combined with the significant protrusion in the mandible and the more horizontal mandibular growth direction, resulted in a decrease in ANB in the unstable group. This indicated that the maxilla remained relatively stable and that the unstable factor was continuing mandibular growth during the pubertal and post-pubertal period. For patients with an

  4. Pollinator effectiveness varies with experimental shifts in flowering time.

    Science.gov (United States)

    Rafferty, Nicole E; Ives, Anthony R

    2012-04-01

    The earlier flowering times exhibited by many plant species are a conspicuous sign of climate change. Altered phenologies have caused concern that species could suffer population declines if they flower at times when effective pollinators are unavailable. For two perennial wildflowers, Tradescantia ohiensis and Asclepias incarnata, we used an experimental approach to explore how changing phenology affects the taxonomic composition of the pollinator assemblage and the effectiveness of individual pollinator taxa. After finding in the previous year that fruit set varied with flowering time, we manipulated flowering onset in greenhouses, placed plants in the field over the span of five weeks, and measured pollinator effectiveness as the number of seeds produced after a single visit to a flower. The average effectiveness of pollinators and the expected rates of pollination success were lower for plants of both species flowering earlier than for plants flowering at historical times, suggesting there could be reproductive costs to earlier flowering. Whereas for A. incarnata, differences in average seed set among weeks were due primarily to changes in the composition of the pollinator assemblage, the differences for T. ohiensis were driven by the combined effects of compositional changes and increases over time in the effectiveness of some pollinator taxa. Both species face the possibility of temporal mismatch between the availability of the most effective pollinators and the onset of flowering, and changes in the effectiveness of individual pollinator taxa through time may add an unexpected element to the reproductive consequences of such mismatches.

  5. Delay time and Hartman effect in strain engineered graphene

    International Nuclear Information System (INIS)

    Chen, Xi; Deng, Zhi-Yong; Ban, Yue

    2014-01-01

    Tunneling times, including group delay and dwell time, are studied for massless Dirac electrons transmitting through a one-dimensional barrier in strain-engineered graphene. The Hartman effect, the independence of group delay on barrier length, is induced by the strain effect, and associated with the transmission gap and the evanescent mode. The influence of barrier height/length and strain modulus/direction on the group delay is also discussed, which provides the flexibility to control the group delay with applications in graphene-based devices. The relationship between group delay and dwell time is finally derived to clarify the nature of the Hartman effect

  6. Effects of daylight savings time changes on stock market volatility.

    Science.gov (United States)

    Berument, M Hakan; Dogan, Nukhet; Onar, Bahar

    2010-04-01

    The presence of daylight savings time effects on stock returns and on stock volatility was investigated using an EGARCH specification to model the conditional variance. The evidence gathered from the major United States stock markets for the period between 1967 and 2007 did not support the existence of the daylight savings time effect on stock returns or on volatility. Returns on the first business day following daylight savings time changes were not lower nor was the volatility higher, as would be expected if there were an effect.

  7. Evaluation of skin moisturizer effects using terahertz time domain imaging

    Science.gov (United States)

    Martinez-Meza, L. H.; Rojas-Landeros, S. C.; Castro-Camus, E.; Alfaro-Gomez, M.

    2018-02-01

    We use terahertz time domain imaging for the evaluation of the effects of skin-moisturizers in vivo. We evaluate three principal substances used in commercial moisturizers: glycerin, hyaluronic acid and lanolin. We image the interaction of the forearm with each of the substances taking terahertz spectra at sequential times. With this, we are able to measure the effect of the substances on the hydration level of the skin in time, determining the feasibility of using THz imaging for the evaluation of the products and their effects on the hydration levels of the skin.

  8. The Effect of Sports and Physical Activity on Elderly Reaction Time and Response Time

    Directory of Open Access Journals (Sweden)

    Abdolrahman Khezri

    2014-07-01

    Full Text Available Objectives: Physical activities ameliorate elderly motor and cognitive performance. The aim of this research is to study the effect of sport and physical activity on elderly reaction time and response time. Methods & Materials: The research method is causal-comparative and its statistical population consists of 60 active and non-active old males over 60 years residing at Mahabad city. Reaction time was measured by reaction timer apparatus, made in Takei Company (YB1000 model. Response time was measured via Nelson’s Choice- Response Movement Test. At first, reaction time and then response time was measured. For data analysis, descriptive statistic, K-S Test and One Sample T Test were used Results K-S Test show that research data was parametric. According to the results of this research, physical activity affected reaction time and response time. Results: of T test show that reaction time (P=0.000 and response time (P=0.000 of active group was statistically shorter than non- active group. Conclusion: The result of current study demonstrate that sport and physical activity, decrease reaction and response time via psychomotor and physiological positive changes.

  9. The Effects of Breaking up Prolonged Sitting Time

    DEFF Research Database (Denmark)

    Benatti, Fabiana Braga; Ried-Larsen, Mathias

    2015-01-01

    on the electronic databases PUBMED and SCOPUS was independently conducted by two researchers. Only prospective intervention studies (controlled and uncontrolled) evaluating the effects of explicitly replacing sitting time with physical activity (including standing) on metabolic parameters as outcomes were included...

  10. Veterans Health Administration Timely and Effective Care Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — A list of VHA hospitals with timely and effective care (process of care) measure data. VHA collects this information through a Quality Improvement Organization...

  11. Department of Defense Timely & Effective Care Data – military hospitals

    Data.gov (United States)

    U.S. Department of Health & Human Services — This file contains U.S. military hospital data for timely & effective care (process of care) measures collected by the Department of Defense (DoD). DoD collects...

  12. The effect of extrinsic motivation on cycle time trial performance

    NARCIS (Netherlands)

    Hulleman, M.; de Koning, J.J.; Hettinga, F.J.; Foster, C.

    2007-01-01

    PURPOSE: Athletes occasionally follow pacing patterns that seem unreasonably aggressive compared with those of prerace performances, potentially because of the motivation provided by competition. This study evaluated the effect of extrinsic motivation on cyclists' time trial performance. METHODS:

  13. Research perspective: Time-of-day effects on noise annoyance

    Science.gov (United States)

    Fields, J. M.

    1980-01-01

    Some of the complications encountered in researching time-of-day effects on noise annoyance are reported. A conceptual framework for further research is provided. Some of the implications for the research methods that should be used are suggested.

  14. Time-dependent effects of cardiovascular exercise on memory

    DEFF Research Database (Denmark)

    Roig, Marc; Thomas, Richard; Mang, Cameron S

    2016-01-01

    We present new evidence supporting the hypothesis that the effects of cardiovascular exercise on memory can be regulated in a time-dependent manner. When the exercise stimulus is temporally coupled with specific phases of the memory formation process, a single bout of cardiovascular exercise may...... be sufficient to improve memory. SUMMARY: The timing of exercise in relation to the information to be remembered is critical to maximize the effects of acute cardiovascular exercise on memory....

  15. Time perspective and positivity effects in Alzheimer's disease.

    Science.gov (United States)

    Bohn, Linzy; Kwong See, Sheree T; Fung, Helene H

    2016-09-01

    This study tested whether time perspective, a central tenant of socioemotional selectivity theory (Carstensen, 2006), moderates positivity effects in emotional memory. To provide measures of time perspective, young (YA; M = 22.48 years), young-old (YO; M = 67.56 years), old-old adults (OO; M = 80.24 years), and participants with moderate severity Alzheimer's disease (PAD; M = 84.28 years) completed a line task and reported subjective age. As expected, YA, YO, and OO reported successively more constrained future time perspectives. PAD showed distortion in time perspective, envisioning a future comparable with the YO, although closer matched in chronological age to OO adults. To evince positivity effects, participants were oriented to pairs of emotional images and were then tested for memory (recall and recognition) of the images. Recall and recognition memory for the images indicated an age-related advantage for positive over negative material (positivity effects). Time perspective, however, did not moderate these age effects. In memory performance, PAD were more comparable with OO adults with whom they shared a similar chronological age, rather than YO adults, who had a corresponding time perspective. These results suggest that age correlates that are shared by PAD and OO, such as reduced processing resources, rather than time perspective, may drive the age associated positivity effects. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  16. Pubertal Stress and Nutrition and their Association with Sexual Orientation and Height in the Add Health Data.

    Science.gov (United States)

    Skorska, Malvina N; Bogaert, Anthony F

    2017-01-01

    A number of studies have indicated that gay men tend to be shorter, on average, than heterosexual men. Less evidence exists that lesbian women are taller, on average, than heterosexual women. The most popular explanation of the association between sexual orientation and height involves prenatal factors, such that, for example, gay men may have been exposed to lower than typical androgens during fetal development, which impacts their height and sexual orientation as adults. An alternative explanation involves stress, given that stress has been associated with sexual minority identification and with lower height. Another alternative explanation involves nutrition, although its relationship is less clear with sexual minority identification. Using the Add Health data, which is a large, nationally representative and longitudinal sample of American adolescents (n = 14,786), we tested a mediation model, such that sexual orientation → pubertal stress/nutrition → height. Within men, we found that gay men (n = 126) were shorter, on average, than heterosexual men (n = 6412). None of the 24 pubertal stress-related and 15 pubertal nutrition-related variables assessed in the Add Health data mediated the relationship between sexual orientation and height in men. Within women, lesbians (n = 75) did not differ significantly in stature compared to heterosexual women (n = 6267). Thus, prenatal mechanisms (e.g., hormones, maternal immune response) are likely better candidates for explaining the height difference between gay men and heterosexual men.

  17. An Effective Time and Management Strategy in Quality Circles.

    Science.gov (United States)

    Halverson, Don E.

    Contending that participation in quality circles enhances effective time management by school administrators and teachers, this guide provides both a theoretical briefing and practical recommendations for better time management. A pre- posttest prefaces a review of basic concepts of quality circles with reference to the work of Abraham Maslow,…

  18. An effective approach to the problem of time

    NARCIS (Netherlands)

    Bojowald, M.; Höhn, P.A.|info:eu-repo/dai/nl/330827952; Tsobanjan, A.

    2010-01-01

    A practical way to deal with the problem of time in quantum cosmology and quantum gravity is proposed. The main tool is effective equations, which mainly restrict explicit considerations to semiclassical regimes but have the crucial advantage of allowing the consistent use of local internal times in

  19. Modeling dynamic effects of promotion on interpurchase times

    NARCIS (Netherlands)

    D. Fok (Dennis); R. Paap (Richard); Ph.H.B.F. Franses (Philip Hans)

    2002-01-01

    textabstractIn this paper we put forward a duration model to analyze the dynamic effects of marketing-mix variables on interpurchase times. We extend the accelerated failure-time model with an autoregressive structure. An important feature of our model is that it allows for different long-run and

  20. The Effect of Police Response Time on Crime Detection

    DEFF Research Database (Denmark)

    Blanes i Vidal, Jordi; Kirchmaier, Tom

    preferred estimate, a 10% increase in response time leads to a 4.6 percentage points decrease in the likelihood of detection. A faster response time also decreases the number of days that it takes for the police to detect a crime, conditional on eventual detection. We find stronger effects for thefts than...

  1. Effect of temperature and time on solvothermal synthesis of ...

    Indian Academy of Sciences (India)

    Effect of temperature and time study on solvothermal synthesis of BaTiO3 revealed that a moderate reaction temperature i.e. 185◦C and longer reaction time favour tetragonal phase stabiliza- tion. Dissolution–precipitation appears to be the transformation mechanism for the crystallization of BaTiO3 from particulate TiO2 ...

  2. Planting time and mulching effect on onion development and seed ...

    African Journals Online (AJOL)

    A field experiment was conducted to evaluate effects of planting time and mulches on bulb growth and seed production of onion (Allium cepa L.) cv. Taherpuri. Planting time and mulches had significant influence on almost all parameters studied. Onion planted on 21 November had better agronomic traits contributing ...

  3. Effective time-independent analysis for quantum kicked systems

    Science.gov (United States)

    Bandyopadhyay, Jayendra N.; Guha Sarkar, Tapomoy

    2015-03-01

    We present a mapping of potentially chaotic time-dependent quantum kicked systems to an equivalent approximate effective time-independent scenario, whereby the system is rendered integrable. The time evolution is factorized into an initial kick, followed by an evolution dictated by a time-independent Hamiltonian and a final kick. This method is applied to the kicked top model. The effective time-independent Hamiltonian thus obtained does not suffer from spurious divergences encountered if the traditional Baker-Cambell-Hausdorff treatment is used. The quasienergy spectrum of the Floquet operator is found to be in excellent agreement with the energy levels of the effective Hamiltonian for a wide range of system parameters. The density of states for the effective system exhibits sharp peaklike features, pointing towards quantum criticality. The dynamics in the classical limit of the integrable effective Hamiltonian shows remarkable agreement with the nonintegrable map corresponding to the actual time-dependent system in the nonchaotic regime. This suggests that the effective Hamiltonian serves as a substitute for the actual system in the nonchaotic regime at both the quantum and classical level.

  4. Effective diffusion in time-periodic linear planar flow

    International Nuclear Information System (INIS)

    Indeikina, A.; Chang, H.

    1993-01-01

    It is shown that when a point source of solute is inserted into a time-periodic, unbounded linear planar flow, the large-time, time-average transport of the solute can be described by classical anisotropic diffusion with constant effective diffusion tensors. For a given vorticity and forcing period, elongational flow is shown to be the most dispersive followed by simple shear and rotational flow. Large-time diffusivity along the major axis of the time-average concentration ellipse, whose alignment is predicted from the theory, is shown to increase with vorticity for all flows and decrease with increasing forcing frequency for elongational flow and simple shear. For the interesting case of rotational flow, there exist discrete resonant frequencies where the time-average major diffusivity reaches local maxima equal to the time-average steady flow case with zero forcing frequency

  5. Temperature has a causal effect on avian timing of reproduction

    NARCIS (Netherlands)

    Visser, M.E.; Holleman, L.J.M.; Caro, S.P.

    2009-01-01

    Many bird species reproduce earlier in years with high spring temperatures, but little is known about the causal effect of temperature. Temperature may have a direct effect on timing of reproduction but the correlation may also be indirect, for instance via food phenology. As climate change has led

  6. Tunneling time and Hartman effect in a ferromagnetic graphene superlattice

    Directory of Open Access Journals (Sweden)

    Farhad Sattari

    2012-03-01

    Full Text Available Using transfer-matrix and stationary phase methods, we study the tunneling time (group delay time in a ferromagnetic monolayer graphene superlattice. The system we peruse consists of a sequence of rectangular barriers and wells, which can be realized by putting a series of electronic gates on the top of ferromagnetic graphene. The magnetization in the two ferromagnetic layers is aligned parallel. We find out that the tunneling time for normal incident is independent of spin state of electron as well as the barrier height and electron Fermi energy while for the oblique incident angles the tunneling time depends on the spin state of electron and has an oscillatory behavior. Also the effect of barrier width on tunneling time is also investigated and shown that, for normal incident, the Hartman effect disappears in a ferromagnetic graphene superlattice but it appears for oblique incident angles when the x component of the electron wave vector in the barrier is imaginary.

  7. Effect of different planting time on different varieties of strawberries

    Science.gov (United States)

    Zhong, Yue; Luo, Ya; Ge, Cong; Mo, Qin; Lin, Yajie; Luo, Shu; Tang, Haoru

    2018-04-01

    The experiment chose two strawberry varieties which planted in two periods of September 10 and September 20, in order to identify the optimum planting time of strawberries by exploring the effects of different planting time on strawberry quality and flowering initially. The results showed that different planting time will affect the growth and quality of strawberry, and the quality of September 10 planting strawberries is better than September 20 planting strawberries while there do exist some differences between strawberry varieties. In summary, the preliminary determination is that in Hanyuan area, the Hong Yan and Zhang Ji's optimum planting time is 10 September.

  8. Wind Effects on Retention Time in Highway Ponds

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby; Larsen, Torben; Rasmussen, Michael R.

    2007-01-01

    is to evaluate the quality of long term simulations based on historical rain series of the pollutant discharges from roads and highways. The idea of this paper is to evaluate the effects of wind on the retention time and compare the retention time for the situation of a spatial uniform wind shear stress...... with the situation of a "real" spatial non-uniform shear stress distribution on the surface of the pond. The result of this paper shows that wind plays a dominant role for the retention time and flow pattern. Furthermore, the results shows that the differences in retention time between the use of uniform and non...

  9. Wind Effects on Retention Time in Highway Ponds

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby; Larsen, Torben; Rasmussen, Michael R.

    2008-01-01

    is to evaluate the quality of long term simulations based on historical rain series of the pollutant discharges from roads and highways. The idea of this paper is to evaluate the effects of wind on the retention time and compare the retention time for the situation of a spatial uniform wind shear stress...... with the situation of a "real" spatial non-uniform shear stress distribution on the surface of the pond. The result of this paper shows that wind plays a dominant role for the retention time and flow pattern. Furthermore, the results shows that the differences in retention time between the use of uniform and non...

  10. Total pubertal growth in patients with juvenile idiopathic arthritis treated with growth hormone: analysis of a single center.

    Science.gov (United States)

    Bechtold, S; Beyerlein, A; Ripperger, P; Roeb, J; Dalla Pozza, R; Häfner, R; Haas, J P; Schmidt, H

    2012-10-01

    Growth failure is a permanent sequelae in juvenile idiopathic arthritis (JIA). The aim of the study was to compare pubertal growth in control and growth hormone (GH) treated JIA subjects. 64 children with JIA at a mean age of 10.38 ± 2.80 years were enrolled and followed until final height (measured in standard deviation (SD) scores). 39 children (20 m) received GH therapy and 24 (9 m) served as controls. GH dose was 0.33 mg/kg/week. Linear regression analysis was performed to identify factors influencing total pubertal growth. Mean total pubertal growth was 21.1 ± 1.3 cm (mean ± SD) in GH treated JIA patients and 13.8 ± 1.5 cm in controls. Final height was significantly higher with GH treatment (-1.67 ± 1.20 SD) compared to controls (-3.20 ± 1.84 SD). Linear regression model identified age at onset of puberty (ß=-4.2,CI: -5.9, -2.6 in controls and ß=-2.3,CI: -3.6, -1.1 in GH treated) as the main factor for total pubertal growth. Final height SDS was determined by the difference to target height at onset of puberty (ß=-0.59;CI: -0.80, -0.37 in controls and ß=-0.30,CI: -0.52, -0.08 in GH treated), age at onset of puberty (ß=0.47;CI:0.02,0.93 in controls and 0.23;CI: -0.00,0.46 in GH treated) and height gain during puberty (ß=0.13;CI:0.05,0.21 in controls and ß=0.11;CI:0.07,0.16 in GH treated). Total pubertal growth in JIA patients treated with GH was increased by a factor of 1.5 greater in comparison to controls leading to a significantly better final height. To maximize final height GH treatment should be initiated early to reduce the height deficit at onset of puberty. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. The effects of the framing of time on delay discounting.

    Science.gov (United States)

    DeHart, William Brady; Odum, Amy L

    2015-01-01

    We examined the effects of the framing of time on delay discounting. Delay discounting is the process by which delayed outcomes are devalued as a function of time. Time in a titrating delay discounting task is often framed in calendar units (e.g., as 1 week, 1 month, etc.). When time is framed as a specific date, delayed outcomes are discounted less compared to the calendar format. Other forms of framing time; however, have not been explored. All participants completed a titrating calendar unit delay-discounting task for money. Participants were also assigned to one of two delay discounting tasks: time as dates (e.g., June 1st, 2015) or time in units of days (e.g., 5000 days), using the same delay distribution as the calendar delay-discounting task. Time framed as dates resulted in less discounting compared to the calendar method, whereas time framed as days resulted in greater discounting compared to the calendar method. The hyperboloid model fit best compared to the hyperbola and exponential models. How time is framed may alter how participants attend to the delays as well as how the delayed outcome is valued. Altering how time is framed may serve to improve adherence to goals with delayed outcomes. © Society for the Experimental Analysis of Behavior.

  12. Evaluation of GnRH analogue testing in diagnosis and management of children with pubertal disorders

    Directory of Open Access Journals (Sweden)

    Hemchand K Prasad

    2012-01-01

    Full Text Available Context: Gonadotrophin releasing hormone (GnRH stimulation test is pivotal in the assessment of children with pubertal disorders. However, lack of availability and high cost often result in the test falling into disfavor. We routinely use the GnRH analogue stimulation test as an alternative at our center. Aim: To present the data on children with endocrine disorders who underwent GnRH agonist stimulation test in pediatric endocrine clinic of a tertiary care referral hospital. Setting and Design: Pediatric endocrine clinic of a tertiary care referral hospital. Retrospective analysis of case records. Materials and Methods: The details pertaining to clinical and radiological parameters and hormonal tests were retrieved from case records of 15 children who underwent GnRH agonist stimulation test from May 2010 to April 2011. Results: Indications for testing with GnRH analogue were evaluation of delayed puberty, diagnosis of precocious puberty, assessment of hormonal suppression in treatment of precocious puberty and micropenis in two, nine, three and one cases, respectively. The results of the test and clinical and radiological parameters were in concordance. The test was also crucial in diagnosing the onset of central precocious puberty in two children with congenital adrenal hyperplasia. Conclusion: GnRH agonist test is a convenient, safe test that can be performed on an out-patient basis and can help the clinicians in the correct diagnosis and appropriate treatment of various puberty-related disorders.

  13. Pedometer assessed physical activity in urban pubertal children: first report from India.

    Science.gov (United States)

    Contractor, Aashish; Bhanushali, Aparna; Changrani, Jyotsna; Angadia, Siddharth; Das, Bibhu R

    2014-11-01

    Inadequate physical activity is a risk factor for several lifestyle diseases. In the current study we have tried to evaluate the physical activity levels in urban Indian pubertal children as well as investigate the relationship between step counts and body composition. A total of 1032 children aged 12 to 15 years wore pedometers for 2 weekdays and 2 weekend days, the final cohort included 910 subjects with 467 boys and 443 girls. Mean weekday steps were 11,062 ± 4741 for boys and 9619 ± 4144 for girls; weekend steps were 10,842 ± 5034 for boys and 9146 ± 5159 for girls, which were both significantly different. The weekend steps were consistently lower in both genders. Analysis of children not meeting a cut-off of 10,000 steps indicated that 45% of the boys aged 12; 54% aged 13; 43% to 48% aged 14 and 50% in the aged 15 did not meet the cut-off. In girls higher levels of inactivity were seen with 58% to 65% aged 12; 69% to 73% aged 13; 49% to 58% aged 14 and 50% to 100% in age-group 15 did not meet the cut-off on weekdays and weekends respectively. The high level of physical inactivity in the representative urban Indian children is a cause of grave concern and necessitates urgent intervention strategies to be formulated.

  14. Peripheral markers of serotonergic and noradrenergic function in post-pubertal, caucasian males with autistic disorder.

    Science.gov (United States)

    Croonenberghs, J; Delmeire, L; Verkerk, R; Lin, A H; Meskal, A; Neels, H; Van der Planken, M; Scharpe, S; Deboutte, D; Pison, G; Maes, M

    2000-03-01

    Some studies have suggested that disorders in the peripheral and central metabolism of serotonin (5-HT) and noradrenaline may play a role in the pathophysiology of autistic disorder. This study examines serotonergic and noradrenergic markers in a study group of 13 male, post-pubertal, caucasian autistic patients (age 12-18 y; I.Q. > 55) and 13 matched volunteers. [3H]-paroxetine binding Kd values were significantly higher in patients with autism than in healthy volunteers. Plasma concentrations of tryptophan, the precursor of 5-HT, were significantly lower in autistic patients than in healthy volunteers. There were no significant differences between autistic and normal children in the serum concentrations of 5-HT, or the 24-hr urinary excretion of 5-hydroxy-indoleacetic acid (5-HIAA), adrenaline, noradrenaline, and dopamine. There were no significant differences in [3H]-rauwolscine binding Bmax or Kd values, or in the serum concentrations of tyrosine, the precursor of noradrenaline, between both study groups. There were highly significant positive correlations between age and 24-hr urinary excretion of 5-HIAA and serum tryptophan. The results suggest that: 1) serotonergic disturbances, such as defects in the 5-HT transporter system and lowered plasma tryptophan, may play a role in the pathophysiology of autism; 2) autism is not associated with alterations in the noradrenergic system; and 3) the metabolism of serotonin in humans undergoes significant changes between the ages of 12 and 18 years.

  15. Association between Physical Activity and Cardiovascular Risk in Chinese Youth Independent of Age and Pubertal Stage

    Directory of Open Access Journals (Sweden)

    Lau Joseph TF

    2010-06-01

    Full Text Available Abstract Background Childhood and adolescence are critical periods of habit formation with substantial tracking of lifestyle and cardiovascular risk into adulthood. There are various guidelines on recommended levels of physical activity in youth of school-age. Despite the epidemic of obesity and diabetes in China, there is a paucity of data in this regard in Chinese youth. We examined the association of self-reported level of physical activity and cardiovascular risk in Hong Kong Chinese youth of school-age. Methods This was a cross-sectional study conducted in 2007-8 in a school setting with 2119 Hong Kong Chinese youth aged 6-20 years. Physical activity level was assessed using a validated questionnaire, CUHK-PARCY (The Chinese University of Hong Kong: Physical Activity Rating for Children and Youth. A summary risk score comprising of waist circumference, blood pressure, fasting plasma glucose and lipids was constructed to quantify cardiovascular risk. Results In this cohort, 21.5% reported high level of physical activity with boys being more active than girls (32.1% versus 14.1%, p Conclusion Self-reported level of physical activity is associated with cardiovascular risk factors in Chinese youth after adjusting for sex and pubertal stage.

  16. Secular trends of growth and pubertal maturation of school children in Southern Thailand.

    Science.gov (United States)

    Jaruratanasirikul, Somchit; Sriplung, Hutcha

    2015-01-01

    In Thailand, studies of growth date back to 1975, but there have been no studies examining any trends in increasing/decreasing growth. To determine if there have been any secular trends of increasing/decreasing growth and/or ages at puberty in Thai children. In 2012, a cross-sectional study of growth was conducted in 3460 children. The median heights and weights and the ages of pubertal maturation were compared with previous studies. Correlations between the secular trends and the health statistics indicators were calculated. From 1975-2012, the median final height of boys and girls had increased by 1.32 and 0.86 cm/decade and weight by 2.49 and 1.76 kg/decade, respectively. In girls, the age at thelarche and menarche had declined by 0.39 and 0.12 years/decade, respectively. In boys, the age at testicular enlargement Tanner II had declined by 0.15 years/decade. Increased physical growth was positively correlated to life expectancy, per capita income and prevalence of overweight/obesity was negatively correlated to prevalence of malnutrition and under-five mortality rate. The positive secular trend towards an increase in growth and a decline in the age at onset of puberty of Thai children is correlated with improvements in overall living conditions in Thailand.

  17. Functional state of reproductive system in pubertal girls having autoimmune thyroiditis

    International Nuclear Information System (INIS)

    Leonova, T.A.

    2003-01-01

    Purpose of the present work is to study the condition of reproductive system in pubertal girls with autoimmune thyroiditis (AT), exposed to radiation as a result of the Chernobyl accident, and to study various clinical symptoms of AT in relation to peculiarities of natural course of the disease, age and absorbed thyroid dose. We performed complex clinical investigation of 225 girls from Belarus with AT aged 11-16. We revealed, that girls with AT irradiated at the age of 0-3 had significant changes in gonadotrophic hormones levels in blood serum in lutein phase at the age of 13-14 in comparison with control groups. In spite of the fact that mainly the meaning investigated hormones were in the range of age norm, at the age of 15-16 among girls being irradiated greater percent of increased meaning of factor LG/FSG is revealed. Girls with AT had symptoms of dysfunction in sensitivity of target organs (ovaries and uterus) receptors. At the age of 15-16 among girls with AT, exposed to radiation, direct dependencies are established between the level of absorbed thyroid doze and meaning of LG and prolactin

  18. Genetic factors modulate the impact of pubertal androgen excess on insulin sensitivity and fertility.

    Directory of Open Access Journals (Sweden)

    Abigail R Dowling

    Full Text Available Polycystic ovary syndrome (PCOS is the most common endocrine disorder of reproductive age women. The syndrome is caused by a combination of environmental influences and genetic predisposition. Despite extensive efforts, the heritable factors contributing to PCOS development are not fully understood. The objective of this study was to test the hypothesis that genetic background contributes to the development of a PCOS-like reproductive and metabolic phenotype in mice exposed to excess DHEA during the pubertal transition. We tested whether the PCOS phenotype would be more pronounced on the diabetes-prone C57BL/6 background than the previously used strain, BALB/cByJ. In addition, we examined strain-dependent upregulation of the expression of ovarian and extra-ovarian candidate genes implicated in human PCOS, genes containing known strain variants, and genes involved with steroidogenesis or insulin sensitivity. These studies show that there are significant strain-related differences in metabolic response to excess androgen exposure during puberty. Additionally, our results suggest the C57BL/6J strain provides a more robust and uniform experimental platform for PCOS research than the BALB/cByJ strain.

  19. Genetic factors modulate the impact of pubertal androgen excess on insulin sensitivity and fertility.

    Science.gov (United States)

    Dowling, Abigail R; Nedorezov, Laura B; Qiu, Xiaoliang; Marino, Joseph S; Hill, Jennifer W

    2013-01-01

    Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of reproductive age women. The syndrome is caused by a combination of environmental influences and genetic predisposition. Despite extensive efforts, the heritable factors contributing to PCOS development are not fully understood. The objective of this study was to test the hypothesis that genetic background contributes to the development of a PCOS-like reproductive and metabolic phenotype in mice exposed to excess DHEA during the pubertal transition. We tested whether the PCOS phenotype would be more pronounced on the diabetes-prone C57BL/6 background than the previously used strain, BALB/cByJ. In addition, we examined strain-dependent upregulation of the expression of ovarian and extra-ovarian candidate genes implicated in human PCOS, genes containing known strain variants, and genes involved with steroidogenesis or insulin sensitivity. These studies show that there are significant strain-related differences in metabolic response to excess androgen exposure during puberty. Additionally, our results suggest the C57BL/6J strain provides a more robust and uniform experimental platform for PCOS research than the BALB/cByJ strain.

  20. Time series trends of the safety effects of pavement resurfacing.

    Science.gov (United States)

    Park, Juneyoung; Abdel-Aty, Mohamed; Wang, Jung-Han

    2017-04-01

    This study evaluated the safety performance of pavement resurfacing projects on urban arterials in Florida using the observational before and after approaches. The safety effects of pavement resurfacing were quantified in the crash modification factors (CMFs) and estimated based on different ranges of heavy vehicle traffic volume and time changes for different severity levels. In order to evaluate the variation of CMFs over time, crash modification functions (CMFunctions) were developed using nonlinear regression and time series models. The results showed that pavement resurfacing projects decrease crash frequency and are found to be more safety effective to reduce severe crashes in general. Moreover, the results of the general relationship between the safety effects and time changes indicated that the CMFs increase over time after the resurfacing treatment. It was also found that pavement resurfacing projects for the urban roadways with higher heavy vehicle volume rate are more safety effective than the roadways with lower heavy vehicle volume rate. Based on the exploration and comparison of the developed CMFucntions, the seasonal autoregressive integrated moving average (SARIMA) and exponential functional form of the nonlinear regression models can be utilized to identify the trend of CMFs over time. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Effectiveness of Multivariate Time Series Classification Using Shapelets

    Directory of Open Access Journals (Sweden)

    A. P. Karpenko

    2015-01-01

    Full Text Available Typically, time series classifiers require signal pre-processing (filtering signals from noise and artifact removal, etc., enhancement of signal features (amplitude, frequency, spectrum, etc., classification of signal features in space using the classical techniques and classification algorithms of multivariate data. We consider a method of classifying time series, which does not require enhancement of the signal features. The method uses the shapelets of time series (time series shapelets i.e. small fragments of this series, which reflect properties of one of its classes most of all.Despite the significant number of publications on the theory and shapelet applications for classification of time series, the task to evaluate the effectiveness of this technique remains relevant. An objective of this publication is to study the effectiveness of a number of modifications of the original shapelet method as applied to the multivariate series classification that is a littlestudied problem. The paper presents the problem statement of multivariate time series classification using the shapelets and describes the shapelet–based basic method of binary classification, as well as various generalizations and proposed modification of the method. It also offers the software that implements a modified method and results of computational experiments confirming the effectiveness of the algorithmic and software solutions.The paper shows that the modified method and the software to use it allow us to reach the classification accuracy of about 85%, at best. The shapelet search time increases in proportion to input data dimension.

  2. A good time to leave?: the sunk time effect in pigeons.

    Science.gov (United States)

    Magalhães, Paula; White, K Geoffrey

    2014-06-01

    Persistence in a losing course of action due to prior investments of time, known as the sunk time effect, has seldom been studied in nonhuman animals. On every trial in the present study, pigeons were required to choose between two response keys. Responses on one key produced food after a short fixed interval (FI) of time on some trials, or on other trials, no food (Extinction) after a longer time. FI and Extinction trials were not differently signaled, were equiprobable, and alternated randomly. Responses on a second Escape key allowed the pigeon to terminate the current trial and start a new one. The optimal behavior was for pigeons to peck the escape key once the duration equivalent to the short FI had elapsed without reward. Durations of the short FI and the longer Extinction schedules were varied over conditions. In some conditions, the pigeons suboptimally responded through the Extinction interval, thus committing the sunk time effect. The absolute duration of the short FI had no effect on the choice between persisting and escaping. Instead, the ratio of FI and Extinction durations determined the likelihood of persistence during extinction. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Isolated torsion of the fallopian tube in a menopausal woman and a pre-pubertal girl: two case reports.

    Science.gov (United States)

    Toyoshima, Masafumi; Mori, Hikaru; Kudo, Kei; Yodogawa, Yuki; Sato, Kazuyo; Kudo, Takako; Igeta, Saori; Makino, Hiromitsu; Shima, Takashi; Matsuura, Rui; Ishigaki, Nobuko; Akagi, Kozo; Takeyama, Yoichi; Iwahashi, Hideki; Yoshinaga, Kosuke

    2015-11-17

    Isolated torsion of the fallopian tube without an ovarian abnormality is an uncommon event, with an incidence of approximately 1 in 1,500,000 females. Isolated torsion of the fallopian tube occurs mostly in reproductive-aged women, and is thus extremely rare in menopausal women and pre-pubertal girls. In case 1, 63-year-old Japanese woman presented with a 2-day history of acute lower abdominal pain. Menopause occurred at 53 years of age. Pelvic ultrasonography showed an enlarged mass (73 × 47 mm) on the right side of her uterus. An urgent laparoscopy was performed based on a presumptive diagnosis of right ovarian tumor torsion. During the laparoscopy, we noted a black, necrotic, solid tumor arising from the distal end of her right fimbria. Her right fallopian tube was twisted with the tumor, but her right ovary was normal and not involved. A laparoscopic tumorectomy with a right salpingectomy was performed. Her post-operative course was uneventful. In case 2, a 10-year-old Japanese girl presented with a 1-day history of lower abdominal pain associated with nausea and vomiting. Menarche had occurred 2 months earlier. A computed tomography and magnetic resonance imaging examination demonstrated a dilated tubal cystic mass with a normal uterus and bilateral ovaries. An urgent laparoscopy was performed based on a presumptive diagnosis of right fallopian tube torsion. During laparoscopy, her right fallopian tube was noted to be dark red, dilated, and twisted several times. Her right fimbria was necrotic-appearing and could not be preserved. Therefore, a laparoscopic right salpingectomy was performed. A histologic examination revealed ischemic changes with congestion of her right fallopian tube, which was consistent with tubal torsion. She had an uncomplicated post-operative course. We have presented two very rare cases of isolated fallopian tubal torsion. Radiologic interventions, such as computed tomography and magnetic resonance imaging, in addition to

  4. Time-Delay Effects on Constitutive Gene Expression*

    International Nuclear Information System (INIS)

    Feng Yan-Ling; Wang Dan; Tang Xu-Lei; Dong Jian-Min

    2017-01-01

    The dynamics of constitutive gene expression with delayed mRNA degradation is investigated, where the intrinsic noise caused by the small number of reactant molecules is introduced. It is found that the oscillatory behavior claimed in previous investigations does not appear in the approximation of small time delay, and the steady state distribution still follows the Poisson law. Furthermore, we introduce the extrinsic noise induced by surrounding environment to explore the effects of this noise and time delay on the Fano factor. Based on a delay Langevin equation and the corresponding Fokker–Planck equation, the distribution of mRNA copy-number is achieved analytically. The time delay and extrinsic noise play similar roles in the gene expression system, that is, they are able to result in the deviation of the Fano factor from 1 evidently. The measured Fano factor for constitutive gene expression is slightly larger than 1, which is perhaps attributed to the time-delay effect. (paper)

  5. Time improvement of photoelectric effect calculation for absorbed dose estimation

    International Nuclear Information System (INIS)

    Massa, J M; Wainschenker, R S; Doorn, J H; Caselli, E E

    2007-01-01

    Ionizing radiation therapy is a very useful tool in cancer treatment. It is very important to determine absorbed dose in human tissue to accomplish an effective treatment. A mathematical model based on affected areas is the most suitable tool to estimate the absorbed dose. Lately, Monte Carlo based techniques have become the most reliable, but they are time expensive. Absorbed dose calculating programs using different strategies have to choose between estimation quality and calculating time. This paper describes an optimized method for the photoelectron polar angle calculation in photoelectric effect, which is significant to estimate deposited energy in human tissue. In the case studies, time cost reduction nearly reached 86%, meaning that the time needed to do the calculation is approximately 1/7 th of the non optimized approach. This has been done keeping precision invariant

  6. The effect of masking in the attentional dwell time paradigm

    DEFF Research Database (Denmark)

    Petersen, Anders

    2009-01-01

    , 1994). In most studies of attentional dwell time, two masked targets have been used. Moore et al. (1996) have criticised the masking of the first target when measuring the attentional dwell time, finding a shorter attentional dwell time when the first mask was omitted. In the presented work, the effect...... of the first mask is further investigated by including a condition where the first mask is presented without a target. The results from individual subjects show that the findings of Moore et al. can be replicated. The results also suggest that presenting the first mask without a target is enough to produce...... an impairment of the second target. Hence, the attentional dwell time may be a combined effect arising from attending to both the first target and its mask....

  7. Depressive realism: effects of depression severity and interpretation time.

    Science.gov (United States)

    McKendree-Smith, N; Scogin, F

    2000-12-01

    This study examined the theory of depressive realism, which posits that depressed people often are more accurate in perceptions and judgments than nondepressed people. Two possible qualifications to this theory were examined: (1) severity of depression moderates the effect, and (2) length of processing time will impact the presence of bias in depressed people, that is, negative bias will develop over time. College students were presented with a bogus personality profile that actually consisted of items previously rated as neutral in desirability. Participants rated these profiles for desirability initially and then again three days later. Results indicated a significant effect of depression severity on desirability rating. Nondepressed and mildly depressed students found their profiles to be more positive than the moderately/severely depressed students, with both groups having scores in the positive range. However, those participants who were moderately/severely depressed showed a negative bias in their ratings. No support was found for the effect of different times of interpretation.

  8. Heart Surgery Waiting Time: Assessing the Effectiveness of an Action

    OpenAIRE

    Badakhshan, Abbas; Arab, Mohammad; Gholipour, Mahin; Behnampour, Naser; Saleki, Saeid

    2015-01-01

    Background: Waiting time is an index assessing patient satisfaction, managerial effectiveness and horizontal equity in providing health care. Although heart surgery centers establishment is attractive for politicians. They are always faced with the question of to what extent they solve patient’s problems. Objectives: The objective of this study was to evaluate factors influencing waiting time in patients of heart surgery centers, and to make recommendations for health-care policy-makers for r...

  9. Time effects of water drainage from deposited back-fill

    International Nuclear Information System (INIS)

    Baranski, L.A.

    1976-01-01

    Time effects of water drainage from deposited back-fill in mine excavations are considered. The time dependence of drainage from the deposited material was determined from ''in situ'' measurements with the aid of radioisotope gauges. The measurements were performed for given drainage conditions and practically constant grain size composition. It was found that in a few hours after the end of the back-filling operation the mechanical properties of the deposited material are practically constant. (author)

  10. Effects of temperature on bleeding time and clotting time in normal male and female volunteers.

    Science.gov (United States)

    Valeri, C R; MacGregor, H; Cassidy, G; Tinney, R; Pompei, F

    1995-04-01

    This study was done to assess the effects of temperature on bleeding time and clotting time in normal male and female volunteers. Open study utilizing normal volunteers. University research laboratory. Fifty-four healthy male and female volunteers, ranging in age from 19 to 35 yrs, who were not receiving medications. The study was done and the samples of venous blood and shed blood collected at the template bleeding time site were obtained at a convenient time for each volunteer. Skin temperature was changed from +20 degrees to +38 degrees C and blood samples were obtained from the antecubital vein of each volunteer. The effect of local skin temperature ranging from +20 degrees to +38 degrees C on bleeding time was evaluated in 38 normal volunteers (19 male and 19 female). Skin temperature was maintained at +20 degrees to +38 degrees C by cooling or warming the forearm. At each temperature, measurements were made of complete blood count, bleeding time, and thromboxane B2 concentrations in shed blood collected at the template bleeding time site and in serum and plasma isolated from blood collected from the antecubital vein. Clotting time studies were measured in 16 normal volunteers (eight male and eight female) at temperatures ranging from +22 degrees to +37 degrees C. At +32 degrees C, the bleeding time was longer and hematocrit was lower in female than in male volunteers. However, at local skin temperatures of < +32 degrees C, both the males and females exhibited significantly increased bleeding times, which were associated with a reduction in shed blood thromboxane B2. Each 1 degree C decrease in temperature was associated with a 15% decrease in the shed blood thromboxane B2 concentration. Clotting times were three times longer at +22 degrees C than at +37 degrees C. Each 1 degree C reduction in the temperature of the clotted blood was associated with a 15% reduction in the serum thromboxane B2 concentration. Our data indicate that during surgical procedures, it

  11. Finite-correlation-time effects in the kinematic dynamo problem

    International Nuclear Information System (INIS)

    Schekochihin, Alexander A.; Kulsrud, Russell M.

    2001-01-01

    Most of the theoretical results on the kinematic amplification of small-scale magnetic fluctuations by turbulence have been confined to the model of white-noise-like (δ-correlated in time) advecting turbulent velocity field. In this work, the statistics of the passive magnetic field in the diffusion-free regime are considered for the case when the advecting flow is finite-time correlated. A new method is developed that allows one to systematically construct the correlation-time expansion for statistical characteristics of the field such as its probability density function or the complete set of its moments. The expansion is valid provided the velocity correlation time is smaller than the characteristic growth time of the magnetic fluctuations. This expansion is carried out up to first order in the general case of a d-dimensional arbitrarily compressible advecting flow. The growth rates for all moments of the magnetic-field strength are derived. The effect of the first-order corrections due to the finite correlation time is to reduce these growth rates. It is shown that introducing a finite correlation time leads to the loss of the small-scale statistical universality, which was present in the limit of the δ-correlated velocity field. Namely, the shape of the velocity time-correlation profile and the large-scale spatial structure of the flow become important. The latter is a new effect, that implies, in particular, that the approximation of a locally-linear shear flow does not fully capture the effect of nonvanishing correlation time. Physical applications of this theory include the small-scale kinematic dynamo in the interstellar medium and protogalactic plasmas

  12. Tunable delay time and Hartman effect in graphene magnetic barriers

    International Nuclear Information System (INIS)

    Ban, Yue; Wang, Lin-Jun; Chen, Xi

    2015-01-01

    Tunable group delay and Hartman effect have been investigated for massless Dirac electrons in graphene magnetic barriers. In the presence of magnetic field, dwell time is found to be equal to net group delay plus the group delay contributing from the lateral shifts. The group delay times are discussed in both cases of normal and oblique incidence, to clarify the nature of Hartman effect. In addition, the group delay in transmission can be modulated from subluminality to superluminality by adjusting the magnetic field, which may also lead to potential applications in graphene-based microelectronics

  13. Effects of etching time on enamel bond strengths.

    Science.gov (United States)

    Triolo, P T; Swift, E J; Mudgil, A; Levine, A

    1993-12-01

    This study evaluated the effects of etching time on bond strengths of composite to enamel. Proximal surfaces of extracted molars were etched with either a conventional etchant (35% phosphoric acid) or one of two dentin/enamel conditioners, 10% maleic acid (Scotchbond Multi-Purpose Etchant), or a solution of oxalic acid, aluminum nitrate, and glycine (Gluma 1 & 2 Conditioner). Each agent was applied for 15, 30, or 60 seconds. Specimens etched with 35% phosphoric acid had the highest mean bond strengths at each etching time. At the manufacturer's recommended application times, the other two agents gave significantly lower shear bond strengths than phosphoric acid.

  14. Effective time management: surgery, research, service, travel, fitness, and family.

    Science.gov (United States)

    Porta, C Rees; Anderson, Michael R; Steele, Scott R

    2013-12-01

    Over 1,500 years ago, the St. Benedictine Monks used planning and strict schedules to increase their productivity. Since then, surgeons have developed several different strategies to manage our time effectively. Finding a balance among career, family, and hobbies is essential for maintaining satisfaction and optimizing productivity. Several recurring themes throughout the medical literature offer potential solutions to help maximize the little time surgeons possess. In this article, we will explore some of the methods and strategies available to help surgeons minimize waste and make the most of the most precious commodity we have-our time.

  15. Effect of equilibration time on Pu desorption from goethite

    International Nuclear Information System (INIS)

    Wong, Jennifer C.; Powell, Brian A.; Zavarin, Mavrik; Begg, James D.; Kersting, Annie B.

    2015-01-01

    It has been suggested that strongly sorbing ions such as plutonium may become irreversibly bound to mineral surfaces over time which has implications for near- and far-field transport of Pu. Batch adsorption-desorption data were collected as a function of time and pH to study the surface stability of Pu on goethite. Pu(IV) was adsorbed to goethite over the pH range 4.2 to 6.6 for different periods of time (1, 6, 15, 34 and 116 d). Following adsorption, Pu was leached from the mineral surface with desferrioxamine B (DFOB), a complexant capable of effectively competing with the goethite surface for Pu. The amount of Pu desorbed from the goethite was found to vary as a function of the adsorption equilibration time, with less Pu removed from the goethite following longer adsorption periods. This effect was most pronounced at low pH. Logarithmic desorption distribution ratios for each adsorption equilibration time were fit to a pH-dependent model. Model slopes decreased between 1 and 116 d adsorption time, indicating that overall Pu(IV) surface stability on goethite surfaces becomes less dependent on pH with greater adsorption equilibration time. The combination of adsorption and desorption kinetic data suggest that non-redox aging processes affect Pu sorption behavior on goethite.

  16. The effects of Present Hedonistic Time Perspective and Past Negative Time Perspective on substance use consequences.

    Science.gov (United States)

    Chavarria, Jesus; Allan, Nicholas P; Moltisanti, Allison; Taylor, Jeanette

    2015-07-01

    The overuse of substances can lead to economic, physical, and social consequences. Previous research has demonstrated associations between time perspective and frequency of substance use, but no studies have investigated time perspective's effect on substance use consequences. This study aimed to fill this gap in the literature. Using an MTurk sample (N=531), latent factor models tested the hypothesis that both Present Hedonistic Time Perspective (PrHTP) and Past Negative Time Perspective PaNTP positively predict alcohol and illicit drug use consequences. Bootstrap analyses were then used to test the hypothesis that PrHTP indirectly affected the relationship between PaNTP and alcohol and illicit drug use consequences. PrHTP significantly predicted alcohol and illicit drug use consequences. PaNTP also significantly predicted alcohol and illicit drug use consequences. PrHTP was found to indirectly affect the relationship between PaNTP and substance use consequences for both alcohol and illicit drugs. The findings are consistent with previous research and introduce time perspective as an individual differences risk factor for substance use consequences. The partial and full indirect effects are consistent with the idea that individuals with a PaNTP may develop a PrHTP, placing them at risk for substance use consequences. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Nernst effect beyond the relaxation-time approximation

    OpenAIRE

    Pikulin, D. I.; Hou, Chang-Yu; Beenakker, C. W. J.

    2011-01-01

    Motivated by recent interest in the Nernst effect in cuprate superconductors, we calculate this magneto-thermo-electric effect for an arbitrary (anisotropic) quasiparticle dispersion relation and elastic scattering rate. The exact solution of the linearized Boltzmann equation is compared with the commonly used relaxation-time approximation. We find qualitative deficiencies of this approximation, to the extent that it can get the sign wrong of the Nernst coefficient. Ziman's improvement of the...

  18. Pyramid Algorithm Framework for Real-Time Image Effects

    DEFF Research Database (Denmark)

    Sangüesa, Adriá Arbués; Ene, Andreea-Daniela; Jørgensen, Nicolai Krogh

    2016-01-01

    Pyramid methods are useful for certain image processing techniques due to their linear time complexity. Implementing them using compute shaders provides a basis for rendering image effects with reduced impact on performance compared to conventional methods. Although pyramid methods are used...... in the game industry, they are not easily accessible to all developers because many game engines do not include built-in support. We present a framework for a popular game engine that allows users to take advantage of pyramid methods for developing image effects. In order to evaluate the performance...... and to demonstrate the framework, a few image effects were implemented. These effects were compared to built-in effects of the same game engine. The results showed that the built-in image effects performed slightly better. The performance of our framework could potentially be improved through optimisation, mainly...

  19. Effect of voice recognition on radiologist reporting time

    International Nuclear Information System (INIS)

    Bhan, S.N.; Coblentz, C.L.; Norman, G.R.; Ali, S.H.

    2008-01-01

    To study the effect that voice recognition (VR) has on radiologist reporting efficiency in a clinical setting and to identify variables associated with faster reporting time. Five radiologists were observed during the routine reporting of 402 plain radiograph studies using either VR (n 217) or conventional dictation (CD) (n = 185). Two radiologists were observed reporting 66 computed tomography (CT) studies using either VR (n - 39) or CD (n - 27). The time spent per reporting cycle, defined as the radiologist's time spent on a study from report finalization to the subsequent report finalization, was compared. As well, characteristics about the radiologist and their reporting style were collected and correlated against reporting time. For plain radiographs, radiologists took 134% (P = 0.048) more time to produce reports using VR, but there was significant variability between radiologists. Significant association with faster reporting times using VR included: English as a first language (r-0.24), use of a template (r -0.34), use of a headset microphone (r -0.46), and increased experience with VR (r -0.43). Experience as a staff radiologist and having previous study for comparison did not correlate with reporting time. For CT, there was no significant difference in reporting time identified between VR and CD (P 0.61). Overall, VR slightly decreases the reporting efficiency of radiologists. However, efficiency may be improved if English is a first language, a headset microphone, and macros and templates are use. (author)

  20. Effects of differentiated music on cycling time trial.

    Science.gov (United States)

    Lim, H B T; Atkinson, G; Karageorghis, C I; Eubank, M R; Eubank, M M

    2009-06-01

    The aim of this study was to investigate the effects of music introduced and removed during a 10-km cycling time trial with reference to Rejeski's parallel processing theory and Karageorghis, Terry and Lane's conceptual framework for the prediction of responses to asynchronous music during sub-maximal exercise. A range of performance variables, ratings of perceived exertion, positive affect, negative affect, and blood lactate were assessed. Eleven males (mean age=24.9, s=6.1 years) completed a 10-km time trial under three conditions; no music, music played initially then removed between 5-10 km, and music played between 5-10 km only. Variables of time, power, cadence, speed, RPE, blood lactate, positive and negative affect were analysed using a ConditionxDistance ANOVA. There was no significant main effect for music conditions for the performance variables, perceived exertion, blood lactate, and affect (p>0.05). Nevertheless, a significant interaction effect for ConditionxDistance was found for cycling speed, with participants cycling 1-1.25 km/h faster at the start of the music introduced time trial than in both the music removed and no music time trials (pmusic during exercise and this finding can be used to extend current theory as it does not specifically address the periodic use music. The fact that participants exercised harder when they expected music to be introduced at a later stage illustrates the behavioural influences that music can engender during self-paced exercise.

  1. Finite life time effects in the coherent exciton transfer

    International Nuclear Information System (INIS)

    Barvik, I.; Herman, P.

    1992-04-01

    The paper addresses a specific problem in the exciton transfer in molecular aggregates, namely the influence of the finite life time effects, on the memory functions entering the Generalized Master Equation (GME) which connect different sites of the system. 7 refs, 2 figs

  2. Effect of liquid nitrogen storage time on the survival and ...

    African Journals Online (AJOL)

    Investigations were undertaken on the effect of liquid nitrogen (LN) storage time on survival and regeneration of somatic embryos of cocoa (Theobroma cacao l.). Somatic embryos from different cocoa genotypes (AMAZ 3-2, AMAZ 10-1, AMAZ 12, SIAL 93, and IMC 14) at 15.45% moisture content were cryopreserved in LN ...

  3. Effects of time pressure and accountability to constituents on negotiation

    NARCIS (Netherlands)

    Mosterd, I.; Rutte, C.G.

    2000-01-01

    A laboratory experiment examined the effects of time pressure (high versus low) and accountability to constituents (not-accountable-to-constituents versus accountable-to-constituents) on the competitiveness of negotiators' interaction and on the outcome (i.e., agreement or impasse) of the

  4. The combined effect of gibberellic acid and long time osmopriming ...

    African Journals Online (AJOL)

    Seeds of this plant have dormancy that causes reduction of seed germination. Experiment was performed as factorial with complete randomized design with 3 factors: polyethylene glycol (PEG) priming, gibberellic acid (GA3) treatment, GA3 application time. This research was performed to evaluate priming effect alone and ...

  5. Distillation time effect on lavender essential oil yield and composition

    Science.gov (United States)

    Lavender (Lavandula angustifolia Mill.) is one of the most widely grown essential oil crops in the world. Commercial extraction of lavender oil is done using steam distillation. The objective of this study was to evaluate the effect of the length of the distillation time (DT) on lavender essential o...

  6. "Deflategate": Time, Temperature, and Moisture Effects on Football Pressure

    Science.gov (United States)

    Blumenthal, Jack; Beljak, Lauren; Macatangay, Dahlia-Marie; Helmuth-Malone, Lilly; McWilliams, Catharina; Raptis, Sofia

    2016-01-01

    In a recent paper in "The Physics Teacher (TPT)", DiLisi and Rarick used the National Football League "Deflategate" controversy to introduce to physics students the physics of a bouncing ball. In this paper, we measure and analyze the environmental effects of time, ambient temperature, and moisture on the internal pressure of…

  7. Modeling Fan Effects on the Time Course of Associative Recognition

    Science.gov (United States)

    Schneider, Darryl W.; Anderson, John R.

    2012-01-01

    We investigated the time course of associative recognition using the response signal procedure, whereby a stimulus is presented and followed after a variable lag by a signal indicating that an immediate response is required. More specifically, we examined the effects of associative fan (the number of associations that an item has with other items…

  8. interactive effect of cowpea variety, dose and exposure time

    African Journals Online (AJOL)

    ACSS

    variety (V), exposure time (T) and dose (D) on the tolerance of C. maculatus to both plant materials. The effect ... laboratories and institutions of higher education in several West .... Each value is the mean±S.E of 20 cowpea seeds. Means ...

  9. Time-reversal symmetry breaking by ac field: Effect of ...

    Indian Academy of Sciences (India)

    deviate from 2 thus signalling on the time-reversal breaking by the ac field. ... is also the parity effect: the enchancement is only present if either P or Q is even. ... analysis (see figure 1) is possible and the ergodic zero-dimensional approx-.

  10. interactive effect of cowpea variety, dose and exposure time

    African Journals Online (AJOL)

    ACSS

    Callosobruchus maculatus has for years remained a serious menace in cowpea in Sub-Sahara Africa. The objective of this study was to investigate the effect of genotypic cowpea (Vigna unguiculata (L.) Walp) varieties, time and dose on C. maculatus exposed to powders of Piper guineense and Eugenia aromatica.

  11. The combined effect of gibberellic acid and long time osmopriming ...

    African Journals Online (AJOL)

    use

    2011-10-26

    Oct 26, 2011 ... Seedling growth responses to PEG priming was similar (in. -1 MPa) or lesser (in ... Seeds can also be primed for short period of time to improve ..... that GA3 is effective in breaking of non-deep physiological dormancy, but it ...

  12. Effects of limiting feed access time and re - alimentation on ...

    African Journals Online (AJOL)

    This experiment was carried out to study the effect of limiting feed access time on the performance of growing rabbit. Forty eighty (48) male rabbits of mixed breeds (Chinchilla x Dutch x California White) with an average weight of 600g. The rabbits were divided into 4 groups of 12 rabbits each after balancing for live weight.

  13. Ultrasound-Assisted Extraction: Effect of Extraction Time and Solvent ...

    African Journals Online (AJOL)

    Purpose: To investigate the influence of extraction conditions assisted by ultrasound on the quality of extracts obtained from Mesembryanthemum edule shoots. Methods: The extraction procedure was carried out in an ultrasonic bath. The effect of two solvents (methanol and ethanol) and two extraction times (5 and 10 min) ...

  14. Effect of Soaking Time on Proximate and Mineral Compositions and ...

    African Journals Online (AJOL)

    Effect of soaking time on some composition of yellow maize was investigated. Yellow maize seeds (Zea mays) were soaked in deionized water for 12, 24, 36 and 48 hours respectively followed by draining, drying and milling. The unsoaked seeds were milled and served as the control. Proximate and mineral compositions ...

  15. Effect of Magnetic Activity on Ionospheric Time Delay at Low ...

    Indian Academy of Sciences (India)

    E) using dual frequency (1575.42 and 1227.60 MHz) GPS measurements. Data from GSV4004A GPS Iono- spheric Scintillation and TEC monitor (GISTM) have been chosen to study these effects. This paper presents the results of ionospheric time delay during quiet and disturbed days for the year 2005. Results show that.

  16. Review of time-dose effects in radiation therapy

    International Nuclear Information System (INIS)

    Peschel, R.E.; Fischer, J.J.

    1980-01-01

    A historical review of conventional fractionation offers little confidence that such treatment is optimal for all tumors. Thus manipulation of time-dose schedules may provide a relatively inexpensive yet potentially useful technique for improving therapeutic results in radiation therapy. Consideration of basic radiobiological principles and animal model data illustrates the complex and heterogeneous nature of normal tissue and tumor response to time-dose effects and supports the hypothesis that better time-dose prescriptions can be found in clinical practice. The number of possible time-dose prescriptions is very large, and a review of the clinical trials using nonconventional fractionation demonstrates that the sampled portion of the total three-dimensional space of time, fraction number, and dose has been very small. Only carefully designed clinical trials can establish the therapeutic advantage of a new treatment schedule, and methods for selecting the most promising schedules are discussed. The use of simple data reduction formulas for time-dose effects should be discarded since they ignore the very complexity and heterogeneity of tissues and tumors which may form the basis of improved clinical results

  17. Effects of cooling time on a closed LWR fuel cycle

    International Nuclear Information System (INIS)

    Arnold, R. P.; Forsberg, C. W.; Shwageraus, E.

    2012-01-01

    In this study, the effects of cooling time prior to reprocessing spent LWR fuel has on the reactor physics characteristics of a PWR fully loaded with homogeneously mixed U-Pu or U-TRU oxide (MOX) fuel is examined. A reactor physics analysis was completed using the CASM04e code. A void reactivity feedback coefficient analysis was also completed for an infinite lattice of fresh fuel assemblies. Some useful conclusions can be made regarding the effect that cooling time prior to reprocessing spent LWR fuel has on a closed homogeneous MOX fuel cycle. The computational analysis shows that it is more neutronically efficient to reprocess cooled spent fuel into homogeneous MOX fuel rods earlier rather than later as the fissile fuel content decreases with time. Also, the number of spent fuel rods needed to fabricate one MOX fuel rod increases as cooling time increases. In the case of TRU MOX fuel, with time, there is an economic tradeoff between fuel handling difficulty and higher throughput of fuel to be reprocessed. The void coefficient analysis shows that the void coefficient becomes progressively more restrictive on fuel Pu content with increasing spent fuel cooling time before reprocessing. (authors)

  18. The effects of immigration on NHS waiting times.

    Science.gov (United States)

    Giuntella, Osea; Nicodemo, Catia; Vargas-Silva, Carlos

    2018-03-01

    This paper analyzes the effects of immigration on waiting times for the National Health Service (NHS) in England. Linking administrative records from Hospital Episode Statistics (2003-2012) with immigration data drawn from the UK Labour Force Survey, we find that immigration reduced waiting times for outpatient referrals and did not have significant effects on waiting times in accident and emergency departments (A&E) and elective care. The reduction in outpatient waiting times can be explained by the fact that immigration increases natives' internal mobility and that immigrants tend to be healthier than natives who move to different areas. Finally, we find evidence that immigration increased waiting times for outpatient referrals in more deprived areas outside of London. The increase in average waiting times in more deprived areas is concentrated in the years immediately following the 2004 EU enlargement and disappears in the medium term (e.g., 3-4 years). Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Clinical and psychological effects of excessive screen time on children.

    Science.gov (United States)

    Domingues-Montanari, Sophie

    2017-04-01

    Over recent years, screen time has become a more complicated concept, with an ever-expanding variety of electronic media devices available throughout the world. Television remains the predominant type of screen-based activity among children. However, computer use, video games and ownership of devices, such as tablets and smart phones, are occurring from an increasingly young age. Screen time, in particular, television viewing, has been negatively associated with the development of physical and cognitive abilities, and positively associated with obesity, sleep problems, depression and anxiety. The physiological mechanisms that underlie the adverse health outcomes related to screen time and the relative contributions of different types of screen and media content to specific health outcomes are unclear. This review discusses the positive and negative effects of screen time on the physiological and psychological development of children. Furthermore, recommendations are offered to parents and clinicians. © 2017 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

  20. Real-time motional Stark effect in jet

    International Nuclear Information System (INIS)

    Alves, D.; Stephen, A.; Hawkes, N.; Dalley, S.; Goodyear, A.; Felton, R.; Joffrin, E.; Fernandes, H.

    2004-01-01

    The increasing importance of real-time measurements and control systems in JET experiments, regarding e.g. Internal Transport Barrier (ITB) and q-profile control, has motivated the development of a real-time motional Stark effect (MSE) system. The MSE diagnostic allows the measurement of local magnetic fields in different locations along the neutral beam path providing, therefore, local measurement of the current and q-profiles. Recently in JET, an upgrade of the MSE diagnostic has been implemented, incorporating a totally new system which allows the use of this diagnostic as a real-time control tool as well as an extended data source for off-line analysis. This paper will briefly describe the technical features of the real-time diagnostic with main focus on the system architecture, which consists of a VME crate hosting three PowerPC processor boards and a fast ADC, all connected via Front Panel Data Port (FPDP). The DSP algorithm implements a lockin-amplifier required to demodulate the JET MSE signals. Some applications for the system will be covered such as: feeding the real-time equilibrium reconstruction code (EQUINOX) and allowing the full coverage analysis of the Neutral Beam time window. A brief comparison between the real-time MSE analysis and the off-line analysis will also be presented

  1. Timing is everything: priority effects alter community invasibility after disturbance.

    Science.gov (United States)

    Symons, Celia C; Arnott, Shelley E

    2014-02-01

    Theory suggests that communities should be more open to the establishment of regional species following disturbance because disturbance may make more resources available to dispersers. However, after an initial period of high invasibility, growth of the resident community may lead to the monopolization of local resources and decreased probability of successful colonist establishment. During press disturbances (i.e., directional environmental change), it remains unclear what effect regional dispersal will have on local community structure if the establishment of later arriving species is affected by early arriving species (i.e., if priority effects are important). To determine the relationship between time-since-disturbance and invasibility, we conducted a fully factorial field mesocosm experiment that exposed tundra zooplankton communities to two emerging stressors - nutrient and salt addition, and manipulated the arrival timing of regional dispersers. Our results demonstrate that invasibility decreases with increasing time-since-disturbance as abundance (nutrient treatments) or species richness (salt treatments) increases in the resident community. Results suggest that the relative timing of dispersal and environmental change will modify the importance of priority effects in determining species composition after a press disturbance.

  2. Effect of transmitter turn-off time on transient soundings

    Science.gov (United States)

    Fitterman, D.V.; Anderson, W.L.

    1987-01-01

    A general procedure for computing the effect of non-zero turn-off time on the transient electromagnetic response is presented which can be applied to forward and inverse calculation methods for any transmitter-receiver configuration. We consider in detail the case of a large transmitter loop which has a receiver coil located at the center of the loop (central induction or in-loop array). For a linear turn-off ramp of width t0, the voltage response is shown to be the voltage due to an ideal step turn-off averaged over windows of width t0. Thus the effect is similar to that obtained by using averaging windows in the receiver. In general when time zero is taken to be the end of the ramp, the apparent resistivity increases for a homogeneous half-space over a limited time range. For time zero taken to be the start of the ramp the apparent resistivity is affected in the opposite direction. The effect of the ramp increases with increasing t0 and first-layer resistivity, is largest during the intermediate stage, and decreases with increasing time. It is shown that for a ramp turn-off, there is no effect in the early and late stages. For two-layered models with a resistive first layer (??1>??2), the apparent resistivity is increased in the intermediate stage. When the first layer is more conductive than the second layer (??1interpretation as shown by field examples; the influence is the greatest on near-surface layer parameters. ?? 1987.

  3. Pubertal-related changes in hypothalamic-pituitary-adrenal axis reactivity and cytokine secretion in response to an immunological stressor.

    Science.gov (United States)

    Goble, K H; Bain, Z A; Padow, V A; Lui, P; Klein, Z A; Romeo, R D

    2011-02-01

    Pubertal development is marked by profound changes in stress reactivity. For example, following a brief stressor, such as foot shock, ether inhalation or restraint, prepubertal rats display a prolonged adrenocorticotrophic hormone (ACTH) and corticosterone response that takes twice as long to return to baseline compared to adults. Pubertal-related differences in the recovery of the hormonal stress response following a more protracted systemic stressor, such as an immunological challenge, have not yet been investigated. Moreover, it is unclear whether an immunological stressor leads to a differential cytokine response in animals before and after pubertal maturation. To examine these issues, we used a single injection of lipopolysaccharide (LPS; 0.1 mg/kg) to induce a hormonal stress and innate immune response and measured plasma ACTH, corticosterone, and the pro-inflammatory cytokines interleukin (IL)-1β and IL-6 in prepubertal and adult male rats 0, 2, 4, 6, 8, or 24 h after LPS exposure. In a follow-up experiment, we assessed neural activation, as indexed by FOS immunohistochemistry, in the paraventricular nucleus of the hypothalamus (PVN) in prepubertal and adult males 0, 4, 8, or 24 h after a 0.1 mg/kg injection of LPS. By contrast to the prolonged response observed in prepubertal animals following a variety of acute stressors, we found that corticosterone and IL-6 responses induced by LPS recover toward baseline faster in prepubertal compared to adult rats. Along with these different peripheral responses, we also found that LPS-induced neural activation in the PVN of prepubertal animals showed a faster return to baseline compared to adults. Together, these data indicate that prepubertal and adult animals react in distinct ways, both peripherally and centrally, to an immunological stressor. © 2011 The Authors. Journal of Neuroendocrinology © 2011 Blackwell Publishing Ltd.

  4. Effect of exposure time and image resolution on fractal dimension

    International Nuclear Information System (INIS)

    An, Byung Mo; Heo, Min Suk; Lee, Seung Pyo; Lee, Sam Sun; Choi, Soon Chul; Park, Tae Won; Kim, Jong Dae

    2002-01-01

    To evaluate the effect of exposure time and image resolution on fractal dimension calculations for determining the optimal range of these two variances. Thirty-one radiographs of the mandibular angle area of sixteen human dry mandibles were taken at different exposure times (0.01, 0.08, 0.16, 0.25, 0.40, 0.64, and 0.80 s). Each radiograph was digitized at 1200 dpi, 8 bit, 256 gray level using a film scanner. We selected an Region of Interest (ROI) that corresponded to the same region as in each radiograph, but the resolution of ROI was degraded to 1000, 800, 600, 500, 400, 300, 200, and 100 dpi. The fractal dimension was calculated by using the tile-counting method for each image, and the calculated values were then compared statistically. As the exposure time and the image resolution increased, the mean value of the fractal dimension decreased, except the case where exposure time was set at 0.01 seconds (alpha = 0.05). The exposure time and image resolution affected the fractal dimension by interaction (p<0.001). When the exposure time was set to either 0.64 seconds or 0.80 seconds, the resulting fractal dimensions were lower, irrespective of image resolution, than at shorter exposure times (alpha = 0.05). The optimal range for exposure time and resolution was determined to be 0.08-0.40 seconds and from 400-1000 dpi, respectively. Adequate exposure time and image resolution is essential for acquiring the fractal dimension using tile-counting method for evaluation of the mandible.

  5. Effects of Social Constraints on Career Maturity: The Mediating Effect of the Time Perspective

    Science.gov (United States)

    Kim, Kyung-Nyun; Oh, Se-Hee

    2013-01-01

    Previous studies have provided mixed results for the effects of social constraints on career maturity. However, there has been growing interest in these effects from the time perspective. Few studies have examined the effects of social constraints on the time perspective which in turn influences career maturity. This study examines the mediating…

  6. mtDNA copy number in oocytes of different sizes from individual pre- and post-pubertal pigs

    DEFF Research Database (Denmark)

    Pedersen, Hanne Skovsgaard; Løvendahl, Peter; Larsen, Knud Erik

    2014-01-01

    from ovaries of 10 pre- and 10 post-pubertal pigs. Cumulus cells were removed and the oocytes were measured (inside-ZP-diameter). Oocytes were transferred to DNAase-free tubes, snap-frozen, and stored at –80°C. The genes ND1 and COX1 were used to determine the mtDNA copy number. Plasmid preparations...... Reproduction 131, 233–245). However, the correlation between size and mtDNA copy number in single oocytes has not been determined. This study describes the relation between oocytes of defined diameters from individual pre- and postpubertal pigs and mtDNA copy number. Cumulus-oocyte complexes were aspirated...

  7. Isolated torsion of the fallopian tube in a menopausal woman and a pre-pubertal girl: two case reports

    OpenAIRE

    Toyoshima, Masafumi; Mori, Hikaru; Kudo, Kei; Yodogawa, Yuki; Sato, Kazuyo; Kudo, Takako; Igeta, Saori; Makino, Hiromitsu; Shima, Takashi; Matsuura, Rui; Ishigaki, Nobuko; Akagi, Kozo; Takeyama, Yoichi; Iwahashi, Hideki; Yoshinaga, Kosuke

    2015-01-01

    Introduction Isolated torsion of the fallopian tube without an ovarian abnormality is an uncommon event, with an incidence of approximately 1 in 1,500,000 females. Isolated torsion of the fallopian tube occurs mostly in reproductive-aged women, and is thus extremely rare in menopausal women and pre-pubertal girls. Case presentations In case 1, 63-year-old Japanese woman presented with a 2-day history of acute lower abdominal pain. Menopause occurred at 53?years of age. Pelvic ultrasonography ...

  8. Radiation effects on time-dependent deformation: Creep and growth

    International Nuclear Information System (INIS)

    Simonen, E.P.

    1989-03-01

    Observations of irradiation creep strain as well as irradiation growth strain and related microstructures are reviewed and compared to mechanisms for radiation effects on time-dependent deformation. Composition, microstructure, stress and temperature affect irradiation creep less than thermal creep. Irradiation creep rates can often dominate thermal creep rates, particularly at low temperatures and low stresses. Irradiation creep mechanisms are classified in two general categories: (1) stress-induced preferential absorption and (2) climb-glide. In the former, creep results from dislocation climb, whereas in the latter, creep results from dislocation glide. The effects of irradiation creep on failure modes in nuclear environments are discussed. 53 refs., 18 figs., 1 tab

  9. Quantum gravity effects in Myers-Perry space-times

    International Nuclear Information System (INIS)

    Litim, Daniel F.; Nikolakopoulos, Konstantinos

    2014-01-01

    We study quantum gravity effects for Myers-Perry black holes assuming that the leading contributions arise from the renormalization group evolution of Newton’s coupling. Provided that gravity weakens following the asymptotic safety conjecture, we find that quantum effects lift a degeneracy of higher-dimensional black holes, and dominate over kinematical ones induced by rotation, particularly for small black hole mass, large angular momentum, and higher space-time dimensionality. Quantum-corrected space-times display inner and outer horizons, and show the existence of a black hole of smallest mass in any dimension. Ultra-spinning solutions no longer persist. Thermodynamic properties including temperature, specific heat, the Komar integrals, and aspects of black hole mechanics are studied as well. Observing a softening of the ring singularity, we also discuss the validity of classical energy conditions

  10. The time factor in dose-effect relationships

    International Nuclear Information System (INIS)

    Jones, H.B.; Grendon, A.; White, M.R.; California Univ., Berkeley

    1976-01-01

    The assumption that carcinogenic risk is proportional to dose fails to consider that probable time of actual cancer incidence. The time lag between exposure and carcinogenic effect for radiation and chemical agents varies as Dosesup(-1/n), with napproximately3. A model is offered explaining that concentration of initially altered cells depends on dose, whereas their chance for development into tumours on their proximity, which varies as Dsup(-1/3). Because of biological variability, n has a range of values. The model implies that tumours resulting from a single exposure should be closely distributed in time, producing a pulse of cases and subsequently being essentially without effect. Testing of the Dsup(-1/3) rule was extended and its model, by further refinement of methods, applied to radiogenic leukaemia risk and to the effect of urethan in inducing lung tumours in mice with and without radiation exposure as a possible cocarcinogen. Radiation did not affect the tumour yield from urethan in mice. Radiogenic leukaemia and lung tumours induced by urethan both occur in proportion to exposure, but the time of their occurrence is limited to a short interval in relation to life span. Similarly, in murine or in human radiogenic leukaemia, leukaemia risk occurs in proportion to exposure, but the time of occurrences is limited to a short interval in relation to life span. In both sets of observations, as well as in other test systems of carcinogenesis, the peak of occurrence or the mean latent period is roughly inversely related to Dsup(-1/3). Applied to lung tumours and leukaemia, the spread of cases about the peak incidence was found to be typically less than a fifth of the life span. Exposure risks do not continue to act over life span. Neoplastic disease risk from carcinogens levels too low to be tested experimentally, theoretically usually lies beyond the life span. The social and economic consequences of a theoretically calculated number of deaths due to those

  11. MEST- avoid next extinction by a space-time effect

    Science.gov (United States)

    Cao, Dayong

    2013-03-01

    Sun's companion-dark hole seasonal took its dark comets belt and much dark matter to impact near our earth. And some of them probability hit on our earth. So this model kept and triggered periodic mass extinctions on our earth every 25 to 27 million years. After every impaction, many dark comets with very special tilted orbits were arrested and lurked in solar system. When the dark hole-Tyche goes near the solar system again, they will impact near planets. The Tyche, dark comet and Oort Cloud have their space-time center. Because the space-time are frequency and amplitude square of wave. Because the wave (space-time) can make a field, and gas has more wave and fluctuate. So they like dense gas ball and a dark dense field. They can absorb the space-time and wave. So they are ``dark'' like the dark matter which can break genetic codes of our lives by a dark space-time effect. So the upcoming next impaction will cause current ``biodiversity loss.'' The dark matter can change dead plants and animals to coal, oil and natural gas which are used as energy, but break our living environment. According to our experiments, which consciousness can use thought waves remotely to change their systemic model between Electron Clouds and electron holes of P-N Junction and can change output voltages of solar cells by a life information technology and a space-time effect, we hope to find a new method to the orbit of the Tyche to avoid next extinction. (see Dayong Cao, BAPS.2011.APR.K1.17 and BAPS.2012.MAR.P33.14) Support by AEEA

  12. Effectiveness of chelation therapy with time after acute uranium intoxication

    International Nuclear Information System (INIS)

    Domingo, J.L.; Ortega, A.; Llobet, J.M.; Corbella, J.

    1990-01-01

    The effect of increasing the time interval between acute uranium exposure and chelation therapy was studied in male Swiss mice. Gallic acid, 4,5-dihydroxy-1,3- benzenedisulfonic acid (Tiron), diethylenetriaminepentaacetic acid (DTPA), and 5-aminosalicylic acid (5-AS) were administered ip at 0, 0.25, 1, 4, and 24 hr after sc injection of 10 mg/kg of uranyl acetate dihydrate. Chelating agents were given at doses equal to one-fourth of their respective LD50 values. Daily elimination of uranium into urine and feces was determined for 4 days after which time the mice were killed, and the concentration of uranium was measured in kidney, spleen, and bone. The excretion of uranium was especially rapid in the first 24 hr. Treatment with Tiron or gallic acid at 0, 0.25, or 1 hr after uranium exposure significantly increased the total excretion of the metal. In kidney and bone, only administration of Tiron at 0, 0.25, or 1 hr after uranium injection, or gallic acid at 1 hr after uranium exposure significantly reduced tissue uranium concentrations. Treatment at later times (4 to 24 hr) did not increase the total excretion of the metal and did not decrease the tissue uranium concentrations 4 days after uranyl acetate administration. The results show that the length of time before initiating chelation therapy for acute uranium intoxication greatly influences the effectiveness of this therapy

  13. Effects of snowmelt on watershed transit time distributions

    Science.gov (United States)

    Fang, Z.; Carroll, R. W. H.; Harman, C. J.; Wilusz, D. C.; Schumer, R.

    2017-12-01

    Snowmelt is the principal control of the timing and magnitude of water flow through alpine watersheds, but the streamflow generated may be displaced groundwater. To quantify this effect, we use a rank StorAge Selection (rSAS) model to estimate time-dependent travel time distributions (TTDs) for the East River Catchment (ERC, 84 km2) - a headwater basin of the Colorado River, and newly designated as the Lawrence Berkeley National Laboratory's Watershed Function Science Focus Area (SFA). Through the SFA, observational networks related to precipitation and stream fluxes have been established with a focus on environmental tracers and stable isotopes. The United Stated Geological Survey Precipitation Runoff Modeling System (PRMS) was used to estimate spatially- and temporally-variable boundary fluxes of effective precipitation (snowmelt & rain), evapotranspiration, and subsurface storage. The DiffeRential Evolution Adaptive Metropolis (DREAM) algorithm was used to calibrate the rSAS model to observed stream isotopic concentration data and quantify uncertainty. The sensitivity of the simulated TTDs to systematic changes in the boundary fluxes was explored. Different PRMS and rSAS model parameters setup were tested to explore how they affect the relationship between input precipitation, especially snowmelt, and the estimated TTDs. Wavelet Coherence Analysis (WCA) was applied to investigate the seasonality of TTD simulations. Our ultimate goal is insight into how the Colorado River headwater catchments store and route water, and how sensitive flow paths and transit times are to climatic changes.

  14. Effect of Time and Temperature on Thickened Infant Formula.

    Science.gov (United States)

    Gosa, Memorie M; Dodrill, Pamela

    2017-04-01

    Unlike adult populations, who primarily depend on liquids for hydration alone, infants rely on liquids to provide them with hydration and nutrition. Speech-language pathologists working within pediatric medical settings often identify dysphagia in patients and subsequently recommend thickened liquids to reduce aspiration risk. Caregivers frequently report difficulty attempting to prepare infant formula to the prescribed thickness. This study was designed to determine (1) the relationship between consistencies in modified barium swallow studies and thickened infant formulas and (2) the effects of time and temperature on the resulting thickness of infant formula. Prepackaged barium consistencies and 1 standard infant formula that was thickened with rice cereal and with 2 commercially available thickening agents were studied. Thickness was determined via a line spread test after various time and temperature conditions were met. There were significant differences between the thickened formula and barium test consistencies. Formula thickened with rice cereal separated over time into thin liquid and solid residue. Formula thickened with a starch-based thickening agent was thicker than the desired consistency immediately after mixing, and it continued to thicken over time. The data from this project suggest that nectar-thick and honey-thick infant formulas undergo significant changes in flow rates within 30 minutes of preparation or if refrigerated and then reheated after 3 hours. Additional empirical evidence is warranted to determine the most reliable methods and safest products for thickening infant formula when necessary for effective dysphagia management.

  15. More about tunnelling times and superluminal tunnelling (Hartmann effect)

    International Nuclear Information System (INIS)

    Olkhovsky, V.S.; Recami, E.; Raciti, F.; Zaichenko, A.

    1995-05-01

    Aims of the present paper are: i) presenting and analysing the results of various numerical calculations on the penetration and return times Pen >, Ret >, during tunnelling inside a rectangular potential barrier, for various penetration depths x f ; ii) putting forth and discussing suitable definitions, besides of the mean values, also of the variances (or dispersions) D τT and D τR for the time durations of transmission and reflection processes; iii)mentioning, moreover, that our definition T > for the average transmission time results to constitute an improvement of the ordinary dwell- time formula; iv) commenting, at last, on the basis of the new numerical results, upon some recent criticism by C.R. Leavens. The paper stresses that numerical evaluations confirm that the approach implied, and implies, the existence of the Hartmann effect: an effect that in these days (due to the theoretical connections between tunnelling and evanescent-wave propagation) is receiving - at Cologne, Berkeley, Florence and Vienna - indirect, but quite interesting, experimental verification

  16. Generation time and effective population size in Polar Eskimos

    Science.gov (United States)

    Matsumura, Shuichi; Forster, Peter

    2008-01-01

    North Greenland Polar Eskimos are the only hunter–gatherer population, to our knowledge, who can offer precise genealogical records spanning several generations. This is the first report from Eskimos on two key parameters in population genetics, namely, generation time (T) and effective population size (Ne). The average mother–daughter and father–son intervals were 27 and 32 years, respectively, roughly similar to the previously published generation times obtained from recent agricultural societies across the world. To gain an insight for the generation time in our distant ancestors, we calculated maternal generation time for two wild chimpanzee populations. We also provide the first comparison among three distinct approaches (genealogy, variance and life table methods) for calculating Ne, which resulted in slightly differing values for the Eskimos. The ratio of the effective to the census population size is estimated as 0.6–0.7 for autosomal and X-chromosomal DNA, 0.7–0.9 for mitochondrial DNA and 0.5 for Y-chromosomal DNA. A simulation of alleles along the genealogy suggested that Y-chromosomal DNA may drift a little faster than mitochondrial DNA in this population, in contrast to agricultural Icelanders. Our values will be useful not only in prehistoric population inference but also in understanding the shaping of our genome today. PMID:18364314

  17. Transit time corrected arterial spin labeling technique aids to overcome delayed transit time effect

    International Nuclear Information System (INIS)

    Yun, Tae Jin; Sohn, Chul-Ho; Yoo, Roh-Eul; Kang, Kyung Mi; Choi, Seung Hong; Kim, Ji-hoon; Park, Sun-Won; Hwang, Moonjung; Lebel, R.M.

    2018-01-01

    This study aimed to evaluate the usefulness of transit time corrected cerebral blood flow (CBF) maps based on multi-phase arterial spin labeling MR perfusion imaging (ASL-MRP). The Institutional Review Board of our hospital approved this retrospective study. Written informed consent was waived. Conventional and multi-phase ASL-MRPs and dynamic susceptibility contrast MR perfusion imaging (DSC-MRP) were acquired for 108 consecutive patients. Vascular territory-based volumes of interest were applied to CBF and time to peak (TTP) maps obtained from DSC-MRP and CBF maps obtained from conventional and multi-phase ASL-MRPs. The concordances between normalized CBF (nCBF) from DSC-MRP and nCBF from conventional and transition time corrected CBF maps from multi-phase ASL-MRP were evaluated using Bland-Altman analysis. In addition, the dependence of difference between nCBF (ΔnCBF) values obtained from DSC-MRP and conventional ASL-MRP (or multi-phase ASL-MRP) on TTP obtained from DSC-MRP was also analyzed using regression analysis. The values of nCBFs from conventional and multi-phase ASL-MRPs had lower values than nCBF based on DSC-MRP (mean differences, 0.08 and 0.07, respectively). The values of ΔnCBF were dependent on TTP values from conventional ASL-MRP technique (F = 5.5679, P = 0.0384). No dependency of ΔnCBF on TTP values from multi-phase ASL-MRP technique was revealed (F = 0.1433, P > 0.05). The use of transit time corrected CBF maps based on multi-phase ASL-MRP technique can overcome the effect of delayed transit time on perfusion maps based on conventional ASL-MRP. (orig.)

  18. Transit time corrected arterial spin labeling technique aids to overcome delayed transit time effect

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Tae Jin; Sohn, Chul-Ho; Yoo, Roh-Eul; Kang, Kyung Mi; Choi, Seung Hong; Kim, Ji-hoon [Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Park, Sun-Won [Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University Boramae Medical Center, Department of Radiology, Seoul (Korea, Republic of); Hwang, Moonjung [GE Healthcare Korea, Seoul (Korea, Republic of); Lebel, R.M. [GE Healthcare Canada, Calgary (Canada)

    2018-03-15

    This study aimed to evaluate the usefulness of transit time corrected cerebral blood flow (CBF) maps based on multi-phase arterial spin labeling MR perfusion imaging (ASL-MRP). The Institutional Review Board of our hospital approved this retrospective study. Written informed consent was waived. Conventional and multi-phase ASL-MRPs and dynamic susceptibility contrast MR perfusion imaging (DSC-MRP) were acquired for 108 consecutive patients. Vascular territory-based volumes of interest were applied to CBF and time to peak (TTP) maps obtained from DSC-MRP and CBF maps obtained from conventional and multi-phase ASL-MRPs. The concordances between normalized CBF (nCBF) from DSC-MRP and nCBF from conventional and transition time corrected CBF maps from multi-phase ASL-MRP were evaluated using Bland-Altman analysis. In addition, the dependence of difference between nCBF (ΔnCBF) values obtained from DSC-MRP and conventional ASL-MRP (or multi-phase ASL-MRP) on TTP obtained from DSC-MRP was also analyzed using regression analysis. The values of nCBFs from conventional and multi-phase ASL-MRPs had lower values than nCBF based on DSC-MRP (mean differences, 0.08 and 0.07, respectively). The values of ΔnCBF were dependent on TTP values from conventional ASL-MRP technique (F = 5.5679, P = 0.0384). No dependency of ΔnCBF on TTP values from multi-phase ASL-MRP technique was revealed (F = 0.1433, P > 0.05). The use of transit time corrected CBF maps based on multi-phase ASL-MRP technique can overcome the effect of delayed transit time on perfusion maps based on conventional ASL-MRP. (orig.)

  19. Time evolution of quenched state and correlation to glassy effects

    International Nuclear Information System (INIS)

    Kilic, K.; Kilic, A.; Altinkok, A.; Yetis, H.; Cetin, O.; Durust, Y.

    2005-01-01

    In this work, dynamic changes generated by the driving current were studied in superconducting bulk polycrystalline YBCO sample via transport relaxation measurements (V-t curves). The evolution of nonlinear V-t curves was interpreted in terms of the formation of resistive and nonresistive flow channels and the spatial reorganization of the transport current in a multiply connected network of weak-link structure. The dynamic re-organization of driving current could cause an enhancement or suppression in the superconducting order parameter due to the magnitude of the driving current and coupling strength of weak-link structure along with the chemical and anisotropic states of the sample as the time proceeds. A nonzero voltage decaying with time, correlated to the quenched state, was recorded when the magnitude of initial driving current is reduced to a finite value. It was found that, after sufficiently long waiting time, the evolution of the quenched state could result in a superconducting state, depending on the magnitude of the driving current and temperature. We showed that the decays in voltage over time are consistent with an exponential time dependence which is related to the glassy state. Further, the effect of doping of organic material Bis dimethyl-glyoximato Copper (II) to YBCO could be monitored apparently via the comparison of the V-t curves corresponding to doped and undoped YBCO samples

  20. Heart Surgery Waiting Time: Assessing the Effectiveness of an Action.

    Science.gov (United States)

    Badakhshan, Abbas; Arab, Mohammad; Gholipour, Mahin; Behnampour, Naser; Saleki, Saeid

    2015-08-01

    Waiting time is an index assessing patient satisfaction, managerial effectiveness and horizontal equity in providing health care. Although heart surgery centers establishment is attractive for politicians. They are always faced with the question of to what extent they solve patient's problems. The objective of this study was to evaluate factors influencing waiting time in patients of heart surgery centers, and to make recommendations for health-care policy-makers for reducing waiting time and increasing the quality of services from this perspective. This cross-sectional study was performed in 2013. After searching articles on PubMed, Elsevier, Google Scholar, Ovid, Magiran, IranMedex, and SID, a list of several criteria, which relate to waiting time, was provided. Afterwards, the data on waiting time were collected by a researcher-structured checklist from 156 hospitalized patients. The data were analyzed by SPSS 16. The Kolmogorov Smirnov and Shapiro tests were used for determination of normality. Due to the non-normal distribution, non-parametric tests, such as Kruskal-Wallis and Mann-Whitney were chosen for reporting significance. Parametric tests also used reporting medians. Among the studied variables, just economic status had a significant relation with waiting time (P = 0.37). Fifty percent of participants had diabetes, whereas this estimate was 43.58% for high blood pressure. As the cause of delay, 28.2% of patients reported financial problems, 18.6% personal problem and 13.5% a delay in providing equipment by the hospital. It seems the studied hospital should review its waiting time arrangements and detach them, as far as possible, from subjective and personal (specialists) decisions. On the other hand, ministries of health and insurance companies should consider more financial support. It is also recommend that hospitals should arrange preoperational psychiatric consultation for increasing patients' emotionally readiness.

  1. Pubertal dependent effects of cadmium on episodic prolactin secretion in male rats

    Energy Technology Data Exchange (ETDEWEB)

    Lafuente, A.; Alvarez-Demanuel, E.; Marquez, N. [Fac. de Cienicas, Orense (Spain). Lab. de Toxicologia; Esquifino, A.I. [Dept. Bioquimica, Facultad de Medicina, Universidad Complutense, 28040-Madrid (Spain)

    1999-02-01

    This work was undertaken to assess if exposure to cadmium related to puberty may affect the episodic pattern of prolactin. Male rats were submitted to cadmium exposure, from day 30 to 60 or from day 60 to 90 of life respectively, at a dose of 50 ppm in the drinking water. Control age-matched rats received cadmium-free water. Prepubertal cadmium administration decreased mean serum prolactin levels and the absolute amplitude of the prolactin pulses. Subchronic exposure to cadmium of adult rats decreased mean serum prolactin levels, the absolute amplitude of the prolactin pulses and their duration, and the mean half-life of the hormone. These results suggest that subchronic cadmium exposure changes the secretory pattern of prolactin in adult male rats in a puberty-dependent way. (orig.) With 1 fig., 1 tab., 37 refs.

  2. The effects of puberty on white matter development in boys.

    Science.gov (United States)

    Menzies, Lara; Goddings, Anne-Lise; Whitaker, Kirstie J; Blakemore, Sarah-Jayne; Viner, Russell M

    2015-02-01

    Neuroimaging studies demonstrate considerable changes in white matter volume and microstructure during adolescence. Most studies have focused on age-related effects, whilst puberty-related changes are not well understood. Using diffusion tensor imaging and tract-based spatial statistics, we investigated the effects of pubertal status on white matter mean diffusivity (MD) and fractional anisotropy (FA) in 61 males aged 12.7-16.0 years. Participants were grouped into early-mid puberty (≤Tanner Stage 3 in pubic hair and gonadal development; n=22) and late-post puberty (≥Tanner Stage 4 in pubic hair or gonadal development; n=39). Salivary levels of pubertal hormones (testosterone, DHEA and oestradiol) were also measured. Pubertal stage was significantly related to MD in diverse white matter regions. No relationship was observed between pubertal status and FA. Regression modelling of MD in the significant regions demonstrated that an interaction model incorporating puberty, age and puberty×age best explained our findings. In addition, testosterone was correlated with MD in these pubertally significant regions. No relationship was observed between oestradiol or DHEA and MD. In conclusion, pubertal status was significantly related to MD, but not FA, and this relationship cannot be explained by changes in chronological age alone. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Effects of integration time on in-water radiometric profiles.

    Science.gov (United States)

    D'Alimonte, Davide; Zibordi, Giuseppe; Kajiyama, Tamito

    2018-03-05

    This work investigates the effects of integration time on in-water downward irradiance E d , upward irradiance E u and upwelling radiance L u profile data acquired with free-fall hyperspectral systems. Analyzed quantities are the subsurface value and the diffuse attenuation coefficient derived by applying linear and non-linear regression schemes. Case studies include oligotrophic waters (Case-1), as well as waters dominated by Colored Dissolved Organic Matter (CDOM) and Non-Algal Particles (NAP). Assuming a 24-bit digitization, measurements resulting from the accumulation of photons over integration times varying between 8 and 2048ms are evaluated at depths corresponding to: 1) the beginning of each integration interval (Fst); 2) the end of each integration interval (Lst); 3) the averages of Fst and Lst values (Avg); and finally 4) the values weighted accounting for the diffuse attenuation coefficient of water (Wgt). Statistical figures show that the effects of integration time can bias results well above 5% as a function of the depth definition. Results indicate the validity of the Wgt depth definition and the fair applicability of the Avg one. Instead, both the Fst and Lst depths should not be adopted since they may introduce pronounced biases in E u and L u regression products for highly absorbing waters. Finally, the study reconfirms the relevance of combining multiple radiometric casts into a single profile to increase precision of regression products.

  4. Timing of food intake predicts weight loss effectiveness.

    Science.gov (United States)

    Garaulet, M; Gómez-Abellán, P; Alburquerque-Béjar, J J; Lee, Y-C; Ordovás, J M; Scheer, F A J L

    2013-04-01

    There is emerging literature demonstrating a relationship between the timing of feeding and weight regulation in animals. However, whether the timing of food intake influences the success of a weight-loss diet in humans is unknown. To evaluate the role of food timing in weight-loss effectiveness in a sample of 420 individuals who followed a 20-week weight-loss treatment. Participants (49.5% female subjects; age (mean ± s.d.): 42 ± 11 years; BMI: 31.4 ± 5.4 kg m(-2)) were grouped in early eaters and late eaters, according to the timing of the main meal (lunch in this Mediterranean population). 51% of the subjects were early eaters and 49% were late eaters (lunch time before and after 1500 hours, respectively), energy intake and expenditure, appetite hormones, CLOCK genotype, sleep duration and chronotype were studied. Late lunch eaters lost less weight and displayed a slower weight-loss rate during the 20 weeks of treatment than early eaters (P=0.002). Surprisingly, energy intake, dietary composition, estimated energy expenditure, appetite hormones and sleep duration was similar between both groups. Nevertheless, late eaters were more evening types, had less energetic breakfasts and skipped breakfast more frequently that early eaters (all; Pmeal (P=0.015) with a higher frequency of minor allele (C) carriers among the late eaters (P=0.041). Neither sleep duration, nor CLOCK SNPs or morning/evening chronotype was independently associated with weight loss (all; P>0.05). Eating late may influence the success of weight-loss therapy. Novel therapeutic strategies should incorporate not only the caloric intake and macronutrient distribution - as is classically done - but also the timing of food.

  5. Contribution of the Endocrine Perspective in the Evaluation of Endocrine Disrupting Chemical Effects

    DEFF Research Database (Denmark)

    Bourguignon, Jean-Pierre; Juul, Anders; Franssen, Delphine

    2016-01-01

    Debate makes science progress. In the field of endocrine disruption, endocrinology has brought up findings that substantiate a specific perspective on the definition of endocrine disrupting chemicals (EDCs), the role of the endocrine system and the endpoints of hormone and EDC actions among other...... issues. This paper aims at discussing the relevance of the endocrine perspective with regard to EDC effects on pubertal timing. Puberty involves particular sensitivity to environmental conditions. Reports about the advancing onset of puberty in several countries have led to the hypothesis...

  6. Time effectiveness of capillary effect improvement of ramie fabrics processed by RF glow discharging

    International Nuclear Information System (INIS)

    Wang Zhiwen; Wei Weixing; He Yanhe; Zhao Yuanqing; Pan Liyiji; Li Xuemei; Shi Shaodui; Li Guangxin

    2010-01-01

    The time effectiveness of capillary effect improvement of ramie fabrics processed by RF glow discharging was studied. The ramie fabrics were processed in fulfilling with different gas (O 2 , N 2 , Ar) by different parameters (such as pressure,power and time) plasma. The capillary effect of the ramie fabrics processed by RF glow discharging was tested at different time. The results indicate that the capillary effect of ramie fabrics processed by RF glow discharging has been improved, the improvement of the capillary effect firstly decrease rapidly, then slowly, and become stable after 15 day, it indicate that improvement of the ramie fabrics capillary has good time effectiveness, and the plasma parameter for the best capillary effect improvement of ramie fabric is 100 W and 40 Pa processed 20 min by oxygen plasma. (authors)

  7. Financial time series analysis based on effective phase transfer entropy

    Science.gov (United States)

    Yang, Pengbo; Shang, Pengjian; Lin, Aijing

    2017-02-01

    Transfer entropy is a powerful technique which is able to quantify the impact of one dynamic system on another system. In this paper, we propose the effective phase transfer entropy method based on the transfer entropy method. We use simulated data to test the performance of this method, and the experimental results confirm that the proposed approach is capable of detecting the information transfer between the systems. We also explore the relationship between effective phase transfer entropy and some variables, such as data size, coupling strength and noise. The effective phase transfer entropy is positively correlated with the data size and the coupling strength. Even in the presence of a large amount of noise, it can detect the information transfer between systems, and it is very robust to noise. Moreover, this measure is indeed able to accurately estimate the information flow between systems compared with phase transfer entropy. In order to reflect the application of this method in practice, we apply this method to financial time series and gain new insight into the interactions between systems. It is demonstrated that the effective phase transfer entropy can be used to detect some economic fluctuations in the financial market. To summarize, the effective phase transfer entropy method is a very efficient tool to estimate the information flow between systems.

  8. Effects of weather and tailings properties on tailings drying times

    Energy Technology Data Exchange (ETDEWEB)

    Gantzer, C.; Fasking, T.; Costello, M.; Greenwood, J. [Barr Engineering, Calgary, AB (Canada)

    2010-07-01

    This PowerPoint presentation presented the results of a study conducted to determine the effects of weather and tailings properties on tailings drying times. Weather conditions have a significant impact the potential evaporation (PE) and actual evaporation (AE) of oil sands tailings. A 2-stage drying of slurry at a constant PE was conducted to determine the shrinkage limit of untreated mature fine tailings (MFT). An evaporation and seepage model was used to determine maximum first-stage drying rates. Measurements were also taken in a wind tunnel. Potential evaporation rates were calculated and evaporative water losses from the MFT were determined. Estimated drying times were presented. Results of the approach were compared with field measurements conducted in a previous study. Results of the study showed that evaporative water loss rates for May through August were limited by the properties of the tailings. Water loss rates were limited by weather for other months in the year-long study. tabs., figs.

  9. Effect of the anti-androgenic endocrine disruptor vinclozolin on embryonic testis cord formation and postnatal testis development and function.

    Science.gov (United States)

    Uzumcu, Mehmet; Suzuki, Hiroetsu; Skinner, Michael K

    2004-01-01

    Vinclozolin is a systemic dicarboximide fungicide that is used on fruits, vegetables, ornamental plants, and turf grass. Vinclozolin and its metabolites are known to be endocrine disruptors and act as androgen receptor antagonists. The hypothesis tested in the current study is that transient embryonic exposure to an anti-androgenic endocrine disruptor at the time of testis determination alters testis development and subsequently influences adult spermatogenic capacity and male reproduction. The effects of vinclozolin on embryonic testicular cord formation in vitro were examined, as well as the effects of transient in utero vinclozolin exposure on postnatal testis development and function. Embryonic day 13 (E13, sperm-positive vaginal smear day = E0) gonads were cultured in the absence or presence of vinclozolin (50-500microM). Vinclozolin treated gonads had significantly fewer cords (P vinclozolin (100 mg/kg/day) between embryonic days 8 and 14 (E8-E14) of development. Testis morphology and function were analyzed from postnatal day (P) 0, pubertal P20, and adult P60. No significant effect of vinclozolin on testis histology or germ cell viability was observed in P0 testis. The pubertal P20 testis from vinclozolin exposed animals had significantly higher numbers of apoptotic germ cells (P vinclozolin exposed males (P vinclozolin exposed animals was higher in adult P60 animals. Observations demonstrate that vinclozolin can effect embryonic testicular cord formation in vitro and that transient in utero exposure to vinclozolin increases apoptotic germ cell numbers in the testis of pubertal and adult animals. This correlated to reduced sperm motility in the adult. In conclusion, transient exposure to vinclozolin during the time of testis differentiation (i.e. cord formation) alters testis development and function. Observations indicate that transient exposure to an anti-androgenic endocrine disruptor during embryonic development causes delayed effects later in adult life

  10. The effect of extrinsic motivation on cycle time trial performance.

    Science.gov (United States)

    Hulleman, Michiel; De Koning, Jos J; Hettinga, Florentina J; Foster, Carl

    2007-04-01

    Athletes occasionally follow pacing patterns that seem unreasonably aggressive compared with those of prerace performances, potentially because of the motivation provided by competition. This study evaluated the effect of extrinsic motivation on cyclists' time trial performance. Well-trained recreational cyclists (N=7) completed four 1500-m laboratory time trials including a practice trial, two self-paced trials, and a trial where a monetary reward was offered. Time, total power output, power output attributable to aerobic and anaerobic metabolic sources, VO2, and HR were measured. The time required for the second, third, and last (extrinsically motivated) time trials was 133.1 +/- 2.1, 134.1 +/- 3.4, and 133.6 +/- 3.0 s, respectively, and was not different (P>0.05). There were no differences for total (396 +/- 19, 397 +/- 23, and 401 +/- 17 W), aerobic (253 +/- 12, 254 +/- 10, and 246 +/- 13 W), and anaerobic (143 +/- 14, 143 +/- 21, and 155 +/- 11 W) power output. The highest VO2 was not different over consecutive time trials (3.76 +/- 0.19, 3.73 +/- 0.16, and 3.71 +/- 0.22 L x min(-1)). When ranked by performance, without reference to the extrinsic motivation (131.9 +/- 2.4, 133.4 +/- 2.4, and 135.4 +/- 2.5 s), there was a significant difference for the first 100 m and from 100 to 300 m in power output, with a larger total power (560 +/- 102, 491 +/- 82, and 493 +/- 93; and 571 +/- 94, 513 +/- 41, and 484 +/- 88 W) and power attributable to anaerobic sources (446 +/- 100, 384 +/- 80, and 324 +/- 43; and 381 +/- 87, 383 +/- 90, and 289 +/- 91 W) for the fastest trial. Extrinsic motivation did not change the time trial performance, suggesting that 1500-m performance is extremely stable and not readily changeable with simple external motivation. The results suggest that spontaneous improvement in performance for time trials of this duration is attributable to greater early power output, which is primarily attributable to anaerobic metabolic sources.

  11. Study of peak broadening effect in floor time histories

    International Nuclear Information System (INIS)

    Soni, R.S.; Kushwaha, H.S.; Mahajan, S.C.; Kakodkar, A.

    1996-01-01

    Seismic design of secondary systems such components and piping is usually carried out by using the floor motions at their support points. These floor motions can be in the form of Floor Response Spectra (FRS) or the Floor Time Histories (FTH). In order to account for the various uncertainties in generating these floor motions, these motions should be peak broadened and smoothened as per the regulatory codes. Presented here in this paper is the methodology to account for such peak broadening effect in the FTH. Results of this study have been compared with the FRS approach and various important conclusions have been arrived at based on the study

  12. Committed effective doses at various times after intakes of radionuclides

    CERN Document Server

    Phipps, A W; Kendall, G M; Silk, T J; Stather, J W

    1991-01-01

    This report contains details of committed effective doses at nine times after intake from intakes by ingestion and inhalation of 1 mu 1 AMAD particles by adults. Data are given for various chemical forms of 359 nuclides. It complements NRPB-R245 which describes the changes which have taken place since the last NRPB compendium of dose per unit intake factors (dose coefficients) and gives summary tables. Information on committed equivalent doses to organs is given in NRPB-M288. The information given in these memoranda is also available as a microcomputer package - NRPB-SR245.

  13. Multiplicity counting from fission detector signals with time delay effects

    Science.gov (United States)

    Nagy, L.; Pázsit, I.; Pál, L.

    2018-03-01

    In recent work, we have developed the theory of using the first three auto- and joint central moments of the currents of up to three fission chambers to extract the singles, doubles and triples count rates of traditional multiplicity counting (Pázsit and Pál, 2016; Pázsit et al., 2016). The objective is to elaborate a method for determining the fissile mass, neutron multiplication, and (α, n) neutron emission rate of an unknown assembly of fissile material from the statistics of the fission chamber signals, analogous to the traditional multiplicity counting methods with detectors in the pulse mode. Such a method would be an alternative to He-3 detector systems, which would be free from the dead time problems that would be encountered in high counting rate applications, for example the assay of spent nuclear fuel. A significant restriction of our previous work was that all neutrons born in a source event (spontaneous fission) were assumed to be detected simultaneously, which is not fulfilled in reality. In the present work, this restriction is eliminated, by assuming an independent, identically distributed random time delay for all neutrons arising from one source event. Expressions are derived for the same auto- and joint central moments of the detector current(s) as in the previous case, expressed with the singles, doubles, and triples (S, D and T) count rates. It is shown that if the time-dispersion of neutron detections is of the same order of magnitude as the detector pulse width, as they typically are in measurements of fast neutrons, the multiplicity rates can still be extracted from the moments of the detector current, although with more involved calibration factors. The presented formulae, and hence also the performance of the proposed method, are tested by both analytical models of the time delay as well as with numerical simulations. Methods are suggested also for the modification of the method for large time delay effects (for thermalised neutrons).

  14. The IPERMOB System for Effective Real-Time Road Travel Time Measurement and Prediction

    OpenAIRE

    Martelli, Francesca; Renda, Maria Elena; Santi, Paolo

    2010-01-01

    Accurate, real-time measurement and estimation of road travel time is considered a central problem in the design of advanced Intelligent Transportation Systems. In particular, whether eective, real-time collection of travel time measurements in a urban area is possible is, to the best of our knowledge, still an open problem. In this paper, we introduce the IPERMOB system for efficient, real-time collection of travel time measurements in urban areas through vehicular networks. We demonstrate t...

  15. Effect of viscosity on tear drainage and ocular residence time.

    Science.gov (United States)

    Zhu, Heng; Chauhan, Anuj

    2008-08-01

    An increase in residence time of dry eye medications including artificial tears will likely enhance therapeutic benefits. The drainage rates and the residence time of eye drops depend on the viscosity of the instilled fluids. However, a quantitative understanding of the dependence of drainage rates and the residence time on viscosity is lacking. The current study aims to develop a mathematical model for the drainage of Newtonian fluids and also for power-law non-Newtonian fluids of different viscosities. This study is an extension of our previous study on the mathematical model of tear drainage. The tear drainage model is modified to describe the drainage of Newtonian fluids with viscosities higher than the tear viscosity and power-law non-Newtonian fluids with rheological parameters obtained from fitting experimental data in literature. The drainage rate through canaliculi was derived from the modified drainage model and was incorporated into a tear mass balance to calculate the transients of total solute quantity in ocular fluids and the bioavailability of instilled drugs. For Newtonian fluids, increasing the viscosity does not affect the drainage rate unless the viscosity exceeds a critical value of about 4.4 cp. The viscosity has a maximum impact on drainage rate around a value of about 100 cp. The trends are similar for shear thinning power law fluids. The transients of total solute quantity, and the residence time agrees at least qualitatively with experimental studies. A mathematical model has been developed for the drainage of Newtonian fluids and power-law fluids through canaliculi. The model can quantitatively explain different experimental observations on the effect of viscosity on the residence of instilled fluids on the ocular surface. The current study is helpful for understanding the mechanism of fluid drainage from the ocular surface and for improving the design of dry eye treatments.

  16. Assessment of circulating sex steroid levels in prepubertal and pubertal boys and girls by a novel ultrasensitive gas chromatography-tandem mass spectrometry method

    DEFF Research Database (Denmark)

    Courant, Frédérique; Aksglæde, Lise; Antignac, Jean-Philippe

    2010-01-01

    Estrogens and androgens play key roles for pubertal onset and sexual maturation. Most currently used immunoassays are not sensitive enough to accurately measure the low circulating levels of sex steroids in children without any signs of puberty. However, this does not exclude that sex steroids ha...

  17. Effect of hydraulic retention time on continuous biocatalytic calcification reactor

    International Nuclear Information System (INIS)

    Isik, Mustafa; Altas, Levent; Kurmac, Yakup; Ozcan, Samet; Oruc, Ozcan

    2010-01-01

    High calcium concentrations in the wastewaters are problematic, because they lead to clogging of pipelines, boilers and heat exchangers through scaling (as carbonate, sulfate or phosphate precipitates), or malfunctioning of aerobic and anaerobic reactors. As a remedy to this problem, the industry typically uses chemical crystallization reactors which are efficient but often require complex monitoring and control and, as a drawback, can give rise to highly alkaline effluents. Biomineralization are emerging as alternative mechanisms for the removal of calcium from aqueous environments. Biocatalytic calcification reactors (BCR) utilize microbial urea hydrolysis by bacteria for the removal of calcium, as calcite, from industrial wastewater. Hydraulic retention time (HRT) effect on calcium removal was studied with a continuous feed BCR reactor treating a simulated pulp paper wastewater. Study showed that HRT is important parameter and HRT of 5-6 h is optimum for calcium removal from calcium-rich wastewaters.

  18. Gender differentiations of cognitive-motor functioning in prepubertal and pubertal children.

    Science.gov (United States)

    Katić, Ratko; Bala, Gustav; Barović, Zdenka

    2012-06-01

    The aim of this study was to determine cognitive and motor status factors in female and male children aged 10-14, as well as developmental and/or integration functions according to gender. The study included 162 girls and 134 boys aged 10-14, divided into four groups: 84 girls aged 10-12 (mean age 11.26, SD 0.68), 84 boys aged 10-12 (mean age 11.41, SD 0.50), 78 girls aged 13-14 (mean age 13.52, SD 0.63) and 50 boys aged 13-14 (mean age 13.21, SD 0.53). The significance of quantitative differences between boys and girls in the overall system of variables was defined based on the results of canonic discriminant analysis of variance, and within each variable based on the results on univariate analysis of variance (ANOVA). In the younger age group (10-12 years), girls were superior to boys in a test assessing flexibility (Seated straddle stretch), whereas, compared to girls, boys had greater strength of the trunk (Crossed-arm sit-ups), greater explosive strength ofjump and sprint type (Standing broad jump and 20 m dash), and coordination (Obstacle course backwards and Steps laterally). In the older age group (13-14 years) differences in flexibility were even more prominent in favor of girls, whereas the differences in explosive strength increased in favor of boys, especially of the throwing type with better agility (Steps laterally), balance (Board balance) and greater static strength of arms and shoulders (Bent-arm hang). In order to determine qualitative differences between pubertal and prepubertal girls and boys, the matrix of variable inter-correlations was factorized by the procedure of principal components procedure, that were then transformed to promax solution. The results showed that cognitive functioning had a significant role in the motor efficacy of girls and boys aged 10 to 14. In the age group of 10-12 years, in females, cognitive functioning is related to the motor system which integrates the regulation of muscle tone with agility/coordination, whereas

  19. The effects of orbital motion on LISA time delay interferometry

    International Nuclear Information System (INIS)

    Cornish, Neil J; Hellings, Ronald W

    2003-01-01

    In an effort to eliminate laser phase noise in laser interferometer spaceborne gravitational wave detectors, several combinations of signals have been found that allow the laser noise to be cancelled out while gravitational wave signals remain. This process is called time delay interferometry (TDI). In the papers that defined the TDI variables, their performance was evaluated in the limit that the gravitational wave detector is fixed in space. However, the performance depends on certain symmetries in the armlengths that are available if the detector is fixed in space, but that will be broken in the actual rotating and flexing configuration produced by the LISA orbits. In this paper we investigate the performance of these TDI variables for the real LISA orbits. First, addressing the effects of rotation, we verify Daniel Shaddock's result that the Sagnac variables α (t), β (t) and γ (t) will not cancel out the laser phase noise, and we also find the same result for the symmetric Sagnac variable ζ (t). The loss of the latter variable would be particularly unfortunate since this variable also cancels out gravitational wave signal, allowing instrument noise in the detector to be isolated and measured. Fortunately, we have found a set of more complicated TDI variables, which we call Δ Sagnac variables, one of which accomplishes the same goal as ζ (t) to good accuracy. Finally, however, as we investigate the effects of the flexing of the detector arms due to non-circular orbital motion, we show that all variables, including the interferometer variables, X(t), Y(t) and Z(t), which survive the rotation-induced loss of direction symmetry, will not completely cancel laser phase noise when the armlengths are changing with time. This unavoidable problem will place a stringent requirement on laser stability of ∼5 Hz Hz -1/2

  20. Effect of gene time on acute radiation mucositis and dermatitis

    International Nuclear Information System (INIS)

    Li Suyan; Gao Li; Yin Weibo; Xu Guozhen; Xiao Guangli

    2002-01-01

    Objective: To evaluate the effect of recombinant human epidermal growth factor (Gene Time) on acute mucositis and dermatitis induced by radiation. Methods: 120 head and neck cancer patients were randomized into 3 groups: 1. Mucositis prophylactic application (MPA) group with control, 2. Mucositis therapeutic application (MTA) group with control and 3. Dermatitis therapeutic application (DTA) group with control. Prophylactic application of drug consisted of spraying the Gene Time preparation on the irradiated skin or mucous membrane as radiotherapy was being carried out. This was compared with control patients who received routine conventional skin care. Therapeutic application was started as grade I radiation mucositis or dermatitis appeared. The evaluation of acute radiation mucositis and dermatitis was done according to the systems proposed by RTOG or EORTC. Results: The results showed that in the MPA group, the rate of radiation mucositis at ≤10 Gy was 20% (4/20) as compared to the 70% (14/20) of the control (P = 0.004). During the course of radiation, the incidences of grade III, IV acute radiation mucositis and dermatitis were always lower than the control. In therapeutic application of Gene Time, the response rate of acute radiation mucositis was also better than the control (90% vs 50%) (P = 0.016) and that of acute dermatitis was similar (95% vs 50%) (P = 0.005). Moreover, the ≤3 d rate of healing of grade III dermatitis in the application group was 3/7 as compared to the 0/14 of the control. Conclusion: Prophylactic application of recombinant human epidermal growth factor is able to postpone the development of radiation mucositis. This preparation is also able to lower the incidence of grade III, IV mucositis and dermatitis both by therapeutic and prophylactic application in addition to the hastened healing of grade III dermatitis

  1. Anxiety Symptoms in African American Youth: The Role of Puberty and Biological Sex

    Science.gov (United States)

    Carter, Rona

    2015-01-01

    This study examined the effects of pubertal status, pubertal timing (actual and perceived), and youth biological sex on symptom dimensions of anxiety (i.e., social, separation, harm avoidance, physical) in African Americans (n = 252; ages 8-12). For girls, results indicated that pubertal status and timing (actual) exerted similar effects for some…

  2. Time-dependent effect in green synthesis of silver nanoparticles

    Directory of Open Access Journals (Sweden)

    Darroudi M

    2011-04-01

    Full Text Available Majid Darroudi1,2, Mansor Bin Ahmad3, Reza Zamiri4, AK Zak5, Abdul Halim Abdullah1,3, Nor Azowa Ibrahim31Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology (ITMA, Universiti Putra Malaysia, Selangor, Malaysia; 2Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran; 3Department of Chemistry, 4Department of Physics, Faculty of Science, Universiti Putra Malaysia, Selangor, Malaysia; 5Low Dimensional Materials Research Center, Department of Physics, Faculty of Science, University of Malaya, Kuala Lumpur, MalaysiaAbstract: The application of “green” chemistry rules to nanoscience and nanotechnology is very important in the preparation of various nanomaterials. In this work, we successfully developed an eco-friendly chemistry method for preparing silver nanoparticles (Ag-NPs in natural polymeric media. The colloidal Ag-NPs were synthesized in an aqueous solution using silver nitrate, gelatin, and glucose as a silver precursor, stabilizer, and reducing agent, respectively. The properties of synthesized colloidal Ag-NPs were studied at different reaction times. The ultraviolet-visible (UV-vis spectra were in excellent agreement with the obtained nanostructure studies performed by transmission electron microscopy (TEM and their size distributions. The prepared samples were also characterized by X-ray diffraction (XRD and atomic force microscopy (AFM. The use of eco-friendly reagents, such as gelatin and glucose, provides green and economic attributes to this work.Keywords: silver nanoparticles, gelatin, green chemistry, time-dependent effect, ultraviolet-visible spectra

  3. Entry time effects and follow-on drug competition.

    Science.gov (United States)

    Andrade, Luiz Flavio; Sermet, Catherine; Pichetti, Sylvain

    2016-01-01

    Pharmaceutical firms have been criticized for concentrating efforts of R&D on the so-called me-too or follow-on drugs. There have been many comments for and against the dissemination of these incremental innovations but few papers have broached the subject from an econometric point of view, possibly because identification of me-too or follow-on drugs is not so obvious. This paper focuses on the impact of entry order on follow-on drug competition in the French market between the years 2001 and 2007. More precisely, this study examines the effects on market share of first entrants in the follow-on drug market and how this possible competitive advantage changes over time. First results are coherent with theoretical microeconomic issues concerning the importance of being first. We find evidence that first movers in the follow-on drug market have the ability to capture and maintain greater market share for a long period of time. The hierarchical market position of follow-on drugs does not seem to be affected by generic drug emergence. From a dynamic perspective, our analysis shows that market share is positively correlated with the ability of follow-on drugs to set prices higher than the average follow-on drug prices in a specific therapeutic class, which means that market power remains considerably important for first movers. Moreover, we found that the optimum level of innovation to maximize market share is the highest one.

  4. Effect of Rainfall on Travel Time and Accuracy of Travel Time prediction with rainfall

    OpenAIRE

    CHUNG, E; EL-FAOUZI, NE; KUWAHARA, M

    2007-01-01

    Travel time is an important parameter to report to travelers. From the user's perspective, accurate predictions and an estimate of their precision are more beneficial than the current travel time since conditions may change significantly before a traveler completes the journey. Past researches have developed travel time prediction models without considering accidents and rain. Normally accident and Rain may cause to increase travel time. Therefore, it may be interesting to consider Rain and a...

  5. The effect of short-time active listening training.

    Science.gov (United States)

    Tatsumi, Asami; Sumiyoshi, Kenichi; Kawaguchi, Hitomi; Sano, Yukiko

    2010-01-01

    We conducted mental health training incorporating active listening for managers at a site of a general chemical company with 1,400 employees. Our purpose was to clarify the effect of active listening training of 2.5h. All subjects were managers. The mental health training was given to 229 managers, 21 times from May 2007 until March 2008. Surveys were conducted from May 2007 to September 2008. The training sessions were conducted in a company meeting room, starting at 2:00 p.m. The importance and significance of listening as a mental health measure and methods of active listening were explained in the training. Afterward, role-playing and follow-up discussions were done twice each. In summaries, participants wrote down what they noticed about listening and gave group presentations. The instructor commented on the presentations, and ended the session by passing out and explaining a paper summarizing what is important in listening. The training was evaluated with a questionnaire distributed at the completion of training, and questionnaires on implementation of what was learned were distributed 1, 3, and 6 mo later. The Active Listening Attitude Scale (ALAS; composed of two scales for method of listening and listening attitude) developed by Mishima et al. was also used before and 1, 3, and 6 mo after the training. In questionnaires distributed on the same day after training, 60% of the 212 respondents said the training time was just right, and 30.1% felt it was too short. The difficulty level of the training was considered appropriate by 77.8%, and 79.7% intended to implement what they had learned. Overall satisfaction was high at 85.9%. In the questionnaire 6 mo after training, 81.4% of the 145 respondents remembered the content of the training and 49.7% said they were practicing what they had learned. They responded that their conversations with subordinates about non-work topics had increased, and communication and support at work had become smoother. ALAS was

  6. Elastodynamic metasurface: Depolarization of mechanical waves and time effects

    Energy Technology Data Exchange (ETDEWEB)

    Boutin, Claude, E-mail: claude.boutin@entpe.fr [Ecole Nationale des Travaux Publics de l' Etat, Université de Lyon, LGCB, UMR CNRS 5513, Vaulx-en-Velin (France); Schwan, Logan [Acoustics Research Center, University of Salford, Newton Building, Salford M5 4WT (United Kingdom); Dietz, Matthew S. [Department of Civil Engineering, University of Bristol, Queen' s Building, Bristol BS8 1TR (United Kingdom)

    2015-02-14

    We report the concept of microstructured surfaces with inner resonance in the field of elastodynamics, so-called elastodynamic metasurfaces. Such metasurfaces allow for wavefield manipulation of mechanical waves by tuning the boundary conditions at specific frequencies. In particular, they can be used to depolarize elastic waves without introducing heterogeneities in the medium itself; the physical means to do so in homogeneous elastic media used to remain, surprisingly, an open question while depolarization is commonplace in electromagnetism. The principle relies on the anisotropic behaviour of a subwavelength array of resonators: Their subwavelength configuration confines the Bragg interferences scattered by resonators into a boundary layer. The effective behaviour of the resonating array is expressed with homogenization as an unconventional impedance, the frequency-dependence, and anisotropy of which lead to depolarization and time effects. The concept of the elastodynamic metasurface is tested experimentally and results bear testament to its efficacy and robustness. Elastodynamic metasurfaces are easily realized and analytically predictable, opening new possibilities in tomography techniques, ultrasonics, geophysics, vibration control, materials and structure design.

  7. Analyzing the effect of gain time on soft task scheduling policies in real-time systems

    OpenAIRE

    Búrdalo Rapa, Luis Antonio; Terrasa Barrena, Andrés Martín; Espinosa Minguet, Agustín Rafael; García Fornes, Ana María

    2012-01-01

    In hard real-time systems, gain time is defined as the difference between the Worst Case Execution Time (WCET) of a hard task and its actual processor consumption at runtime. This paper presents the results of an empirical study about how the presence of a significant amount of gain time in a hard real-time system questions the advantages of using the most representative scheduling algorithms or policies for aperiodic or soft tasks in fixed-priority preemptive systems. The work presented here...

  8. Fast-Response-Time Shape-Memory-Effect Foam Actuators

    Science.gov (United States)

    Jardine, Peter

    2010-01-01

    Bulk shape memory alloys, such as Nitinol or CuAlZn, display strong recovery forces undergoing a phase transformation after being strained in their martensitic state. These recovery forces are used for actuation. As the phase transformation is thermally driven, the response time of the actuation can be slow, as the heat must be passively inserted or removed from the alloy. Shape memory alloy TiNi torque tubes have been investigated for at least 20 years and have demonstrated high actuation forces [3,000 in.-lb (approximately equal to 340 N-m) torques] and are very lightweight. However, they are not easy to attach to existing structures. Adhesives will fail in shear at low-torque loads and the TiNi is not weldable, so that mechanical crimp fits have been generally used. These are not reliable, especially in vibratory environments. The TiNi is also slow to heat up, as it can only be heated indirectly using heater and cooling must be done passively. This has restricted their use to on-off actuators where cycle times of approximately one minute is acceptable. Self-propagating high-temperature synthesis (SHS) has been used in the past to make porous TiNi metal foams. Shape Change Technologies has been able to train SHS derived TiNi to exhibit the shape memory effect. As it is an open-celled material, fast response times were observed when the material was heated using hot and cold fluids. A methodology was developed to make the open-celled porous TiNi foams as a tube with integrated hexagonal ends, which then becomes a torsional actuator with fast response times. Under processing developed independently, researchers were able to verify torques of 84 in.-lb (approximately equal to 9.5 Nm) using an actuator weighing 1.3 oz (approximately equal to 37 g) with very fast (less than 1/16th of a second) initial response times when hot and cold fluids were used to facilitate heat transfer. Integrated structural connections were added as part of the net shape process, eliminating

  9. Fluoride exposure changed the structure and the expressions of HSP related genes in testes of pubertal rats.

    Science.gov (United States)

    Zhao, Yangfei; Zhao, Jun; Wang, Jinming; Wang, Jundong

    2017-10-01

    Previous studies have indicated that fluoride exposure damaged the male reproductive function; however, the cellular mechanism of fluoride-induced testicular toxicity is still unclear. In this study, twenty-two female pregnant Wistar rats were allotted randomly to two groups: control (deionized water) and sodium fluoride (NaF, contain F - : 67.86 mg/L) groups. After delivery, the dosage was continued for 15 weeks for puppies. Twelve rats in each group were tested at 6 and 9 (pubertal); 12 and 15 (mature) weeks of age. Our results suggested that organ coefficient of epididymis was significantly decreased in the mature (12 and 15 week-old) rats. Epididymal sperm abnormality and femur fluoride concentration were increased with the concomitant decrease in sperm motility and concentration in these experimental periods. Compared to the control, in the NaF group, the seminiferous tubules of each age were reduced in terms of diameter and thickness. The sperm cells were lost and shedding and finally disappeared after 9 weeks. mRNA and protein levels of HSP27 and 90 were decreased with a concomitant increase in HSP70 and HSF mRNA and protein levels in NaF exposed rats. The mRNA and protein levels of HSP27 and HSF (only mRNA) were significantly increased in NaF treated rats at 9 and 15 weeks of age, respectively. In summary, these results emphasize that NaF induces testicular and sperm abnormalities through the involvement of HSPs especially during the pubertal period. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Endocrine and molecular investigations in a cohort of 25 adolescent males with prominent/persistent pubertal gynecomastia.

    Science.gov (United States)

    Paris, F; Gaspari, L; Mbou, F; Philibert, P; Audran, F; Morel, Y; Biason-Lauber, A; Sultan, C

    2016-03-01

    Pubertal gynecomastia is a common condition observed in up to 65% of adolescent males. It is usually idiopathic and tends to regress within 1-2 years. In this descriptive cross-sectional study, we investigated 25 adolescent males with prominent (>B3) and/or persistent (>2 years) pubertal gynecomastia (P/PPG) to determine whether a hormonal/genetic defect might underline this condition. Endocrine investigation revealed the absence of hormonal disturbance for 18 boys (72%). Three patients presented Klinefelter syndrome and three a partial androgen insensitivity syndrome (PAIS) as a result of p.Ala646Asp and p.Ala45Gly mutations of the androgen receptor gene. The last patient showed a 17α-hydroxylase/17,20-lyase deficiency as a result of a compound heterozygous mutation of the CYP17A1 gene leading to p.Pro35Thr(P35T) and p.Arg239Stop(R239X) in the P450c17 protein. Enzymatic activity was analyzed: the mutant protein bearing the premature stop codon R239X showed a complete loss of 17α-hydroxylase and 17,20-lyase activity. The mutant P35T seemed to retain 15-20% of 17α-hydroxylase and about 8-10% of 17,20-lyase activity. This work demonstrates that P/PPG had an endocrine/genetic cause in 28% of our cases. PAIS may be expressed only by isolated gynecomastia as well as by 17α-hydroxylase/17,20-lyase deficiency. Isolated P/PPG is not always a 'physiological' condition and should thus be investigated through adequate endocrine and genetic investigations, even though larger studies are needed to better determine the real prevalence of genetic defects in such patients. © 2016 American Society of Andrology and European Academy of Andrology.

  11. Pubertal development and fertility in survivors of childhood acute myeloid leukemia treated with chemotherapy only: a NOPHO-AML study.

    Science.gov (United States)

    Molgaard-Hansen, Lene; Skou, Anne-Sofie; Juul, Anders; Glosli, Heidi; Jahnukainen, Kirsi; Jarfelt, Marianne; Jónmundsson, Guðmundur K; Malmros, Johan; Nysom, Karsten; Hasle, Henrik

    2013-12-01

    More than 60% of children with acute myeloid leukemia (AML) become long-term survivors. Most are cured using chemotherapy without hematopoietic stem cell transplantation (HSCT). We report on pubertal development and compare self-reported parenthood among AML survivors and their siblings. We included 137 children treated for AML according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO)-AML-84, -88, and -93 trials, who were alive by June 2007. Patients with relapse or treated with HSCT were excluded. AML survivors participated in a physical and biochemical examination (n = 102) and completed a questionnaire (n = 101). One of their siblings completed an identical questionnaire (n = 84). At a median follow-up of 11 years (range 5-25) after diagnosis of AML the survivors (median age 16 years, range 5-36) were either prepubertal or had entered puberty normally. Serum levels of FSH, LH, testosterone, estradiol, sex hormone binding globulin (SHBG), inhibin A and B, and testicular volumes were within normal ranges. Anti-Müllerian hormone (AMH) levels were decreased in 5 of 40 postpubertal females. Mean reported age at menarche was 13.1 (range 11-17) years. Among survivors 15 years of age or older 31% of females reported pregnancies and 9% of males reported pregnancies in their partners, rates comparable with the frequency reported by their siblings. Most AML survivors treated with chemotherapy had normal pubertal development and fertility, however, AMH levels were decreased in 13% of postpubertal females. Longer follow-up is necessary to evaluate possible risk of premature ovarian failure. © 2013 Wiley Periodicals, Inc.

  12. Single machine total completion time minimization scheduling with a time-dependent learning effect and deteriorating jobs

    Science.gov (United States)

    Wang, Ji-Bo; Wang, Ming-Zheng; Ji, Ping

    2012-05-01

    In this article, we consider a single machine scheduling problem with a time-dependent learning effect and deteriorating jobs. By the effects of time-dependent learning and deterioration, we mean that the job processing time is defined by a function of its starting time and total normal processing time of jobs in front of it in the sequence. The objective is to determine an optimal schedule so as to minimize the total completion time. This problem remains open for the case of -1 < a < 0, where a denotes the learning index; we show that an optimal schedule of the problem is V-shaped with respect to job normal processing times. Three heuristic algorithms utilising the V-shaped property are proposed, and computational experiments show that the last heuristic algorithm performs effectively and efficiently in obtaining near-optimal solutions.

  13. Distillation time effect on lavender essential oil yield and composition.

    Science.gov (United States)

    Zheljazkov, Valtcho D; Cantrell, Charles L; Astatkie, Tess; Jeliazkova, Ekaterina

    2013-01-01

    Lavender (Lavandula angustifolia Mill.) is one of the most widely grown essential oil crops in the world. Commercial extraction of lavender oil is done using steam distillation. The objective of this study was to evaluate the effect of the length of the distillation time (DT) on lavender essential oil yield and composition when extracted from dried flowers. Therefore, the following distillation times (DT) were tested in this experiment: 1.5 min, 3 min, 3.75 min, 7.5 min, 15 min, 30 min, 60 min, 90 min, 120 min, 150 min, 180 min, and 240 min. The essential oil yield (range 0.5-6.8%) reached a maximum at 60 min DT. The concentrations of cineole (range 6.4-35%) and fenchol (range 1.7-2.9%) were highest at the 1.5 min DT and decreased with increasing length of the DT. The concentration of camphor (range 6.6-9.2%) reached a maximum at 7.5-15 min DT, while the concentration of linalool acetate (range 15-38%) reached a maximum at 30 min DT. Results suggest that lavender essential oil yield may not increase after 60 min DT. The change in essential oil yield, and the concentrations of cineole, fenchol and linalool acetate as DT changes were modeled very well by the asymptotic nonlinear regression model. DT may be used to modify the chemical profile of lavender oil and to obtain oils with differential chemical profiles from the same lavender flowers. DT must be taken into consideration when citing or comparing reports on lavender essential oil yield and composition.

  14. The Effects of Spaceflight on the Rat Circadian Timing System

    Science.gov (United States)

    Fuller, Charles A.; Murakami, Dean M.; Hoban-Higgins, Tana M.; Fuller, Patrick M.; Robinson, Edward L.; Tang, I.-Hsiung

    2003-01-01

    Two fundamental environmental influences that have shaped the evolution of life on Earth are gravity and the cyclic changes occurring over the 24-hour day. Light levels, temperature, and humidity fluctuate over the course of a day, and organisms have adapted to cope with these variations. The primary adaptation has been the evolution of a biological timing system. Previous studies have suggested that this system, named the circadian (circa - about; dies - a day) timing system (CTS), may be sensitive to changes in gravity. The NASA Neurolab spaceflight provided a unique opportunity to evaluate the effects of microgravity on the mammalian CTS. Our experiment tested the hypotheses that microgravity would affect the period, phasing, and light sensitivity of the CTS. Twenty-four Fisher 344 rats were exposed to 16 days of microgravity on the Neurolab STS-90 mission, and 24 Fisher 344 rats were also studied on Earth as one-G controls. Rats were equipped with biotelemetry transmitters to record body temperature (T(sub b)) and heart rate (HR) continuously while the rats moved freely. In each group, 18 rats were exposed to a 24-hour light-dark (LD 12:12) cycle, and six rats were exposed to constant dim red-light (LL). The ability of light to induce a neuronal activity marker (c-fos) in the circadian pacemaker of the brain, the suprachiasmatic nucleus (SCN), was examined in rats studied on flight days two (FD2) and 14 (FD14), and postflight days two (R+1) and 14 (R+13). The flight rats in LD remained synchronized with the LD cycle. However, their T(sub b), rhythm was markedly phase-delayed relative to the LD cycle. The LD flight rats also had a decreased T(sub b) and a change in the waveform of the T(sub b) rhythm compared to controls. Rats in LL exhibited free-running rhythms of T(sub b), and HR; however, the periods were longer in microgravity. Circadian period returned to preflight values after landing. The internal phase angle between rhythms was different in flight than

  15. Effect of myopia onset time for macula choroidal thickness

    Directory of Open Access Journals (Sweden)

    Shi-Ming Wang

    2016-03-01

    Full Text Available AIM:To investigate the effect of onset time(Tfor macula choroidal thickness(CTin myopia patient. METHODS:A prospective cohort study was designed.One hundred and twenty-two myopia patients(244 eyes; 67 male and 55 female; aged 30~41 years, mean 35.1±4.6 years oldwho received preoperative examinations from March 2014 to April 2015 were recruited in this study. The patients were divided into three groups according to onset time(T:group A(T≤5a, group B(5aF=1.56,P>0.05,age(F=2.13,P>0.05,best corrected visual acuity(BCVA, F=1.41,P>0.05,corneal curvature(F=1.65,P>0.05and axial length(F=1.89,P>0.05among the three groups. The choroid in macular region was measured by enhanced depth imaging(EDIusing spectral-domain optical coherence tomography(SD-OCT. This study recorded the CT at subfoveal(SFCT, 1mm at temporal(T1mm, nasal(N1mm, superior(S1mmand inferior(I1mmto the fovea and 3mm temporal(T3mm, nasal(N3mm, superior(S3mmand inferior(I3mmto the fovea, respectively. The differences of CT at the same position among the three groups were analyzed.RESULTS:The mean SFCT for group A,B,C were 238.32±57.95μm, 230.58±67.21μm, 221.63±62.37μm respectively in this study. The CT was found no significant difference in different locations except N3mm(tA-B=4.34,P3mm(tB-C=7.61,P3mm(t=0.76,P>0.05between group A and C. Significant difference was found at N3mm(tA-B=4.31,t B-C=7.59,tA-C=12.18; PCONCLUSION:The choroidal thickness decreases as the myopia onset time is earlier, especially at nasal.

  16. [Evaluation of nutrition mode and nutritional status and pro health education of children during the period of pubertal spurt in the city of Szczecin].

    Science.gov (United States)

    Goluch-Koniuszy, Zuzanna; Friedrich, Mariola; Radziszewska, Magdalena

    2009-01-01

    This research was aimed at evaluation of the method of nutrition and the state of nutrition in the children aged 13 during the period of pubertal spurt who had their body mass, body height and waist measurement defined. These values led to calculation of BMI, WC, and WHtR indicators, which were related to centile distribution of children from Warszawa and Lódź. Only in 63.6% of girls and 68.9% of boys from Szczecin schools the value of BMI was proper. The problem of accumulation of fat tissue (WC > or = 90 c) around the waist refers to nearly 14% of girls and 9.4% of boys. The value of the indicator WHtR > or = 90 c was found in 11% of the children under research. Children with overweight (BMI 90-97 c) and obesity (BMI > or = 97 c) were selected based on the value of BMI indicator. Their menus of three chosen at random weekdays were obtained. Analysis of the nutrition method of children with overweight and obesity showed low energy value of the diet, general protein, complex carbohydrates, cellulose, mineral components (Ca, Mg, Fe, Cu, Zn), A, E (girls), C (boys), group B vitamins and also liquids deficiency. The children have undergone a special pro health education in the form of "live" workshops and 3 months after an evaluation inquiry was conducted to assess the effects of the workshops. The analysis of the evaluation inquiry showed that the children have included in their diet breakfasts and afternoon snacks and to their main meal menus whole wheat products, larger quantity of vegetables, fruit and water. It has been also established that sweets, meals of fast food types, chips, pizzy and energizing drinks have been limited.

  17. The effect of chromatic and luminance information on reaction times.

    Science.gov (United States)

    O'Donell, Beatriz M; Barraza, Jose F; Colombo, Elisa M

    2010-07-01

    We present a series of experiments exploring the effect of chromaticity on reaction time (RT) for a variety of stimulus conditions, including chromatic and luminance contrast, luminance, and size. The chromaticity of these stimuli was varied along a series of vectors in color space that included the two chromatic-opponent-cone axes, a red-green (L-M) axis and a blue-yellow [S - (L + M)] axis, and intermediate noncardinal orientations, as well as the luminance axis (L + M). For Weber luminance contrasts above 10-20%, RTs tend to the same asymptote, irrespective of chromatic direction. At lower luminance contrast, the addition of chromatic information shortens the RT. RTs are strongly influenced by stimulus size when the chromatic stimulus is modulated along the [S - (L + M)] pathway and by stimulus size and adaptation luminance for the (L-M) pathway. RTs are independent of stimulus size for stimuli larger than 0.5 deg. Data are modeled with a modified version of Pieron's formula with an exponent close to 2, in which the stimulus intensity term is replaced by a factor that considers the relative effects of chromatic and achromatic information, as indexed by the RMS (square-root of the cone contrast) value at isoluminance and the Weber luminance contrast, respectively. The parameters of the model reveal how RT is linked to stimulus size, chromatic channels, and adaptation luminance and how they can be interpreted in terms of two chromatic mechanisms. This equation predicts that, for isoluminance, RTs for a stimulus lying on the S-cone pathway are higher than those for a stimulus lying on the L-M-cone pathway, for a given RMS cone contrast. The equation also predicts an asymptotic trend to the RT for an achromatic stimulus when the luminance contrast is sufficiently large.

  18. Childhood body mass index at 5.5 years mediates the effect of prenatal maternal stress on daughters' age at menarche: Project Ice Storm.

    Science.gov (United States)

    Duchesne, A; Liu, A; Jones, S L; Laplante, D P; King, S

    2017-04-01

    Early pubertal timing is known to put women at greater risk for adverse physiological and psychological health outcomes. Of the factors that influence girls' pubertal timing, stress experienced during childhood has been found to advance age at menarche (AAM). However, it is not known if stress experienced by mothers during or in the months before conception can be similarly associated with earlier pubertal timing. Prenatal maternal stress (PNMS) is associated with metabolic changes, such as increased childhood adiposity and risk of obesity, that have been associated with earlier menarchal age. Using a prospective longitudinal design, the present study tested whether PNMS induced by a natural disaster is either directly associated with earlier AAM, or whether there is an indirect association mediated through increased girls' body mass index (BMI) during childhood. A total of 31 girls, whose mothers were exposed to the Quebec's January 1998 ice storm during pregnancy were followed from 6 months to 5 1/2 to 5.5 years of age. Mother's stress was measured within 6 months of the storm. BMI was measured at 5.5 years, and AAM was assessed through teen's self-report at 13.5 and 15.5 years of age. Results revealed that greater BMI at 5.5 years mediated the effect of PNMS on decreasing AAM [B=-0.059, 95% confidence intervals (-0.18, -0.0035)]. The present study is the first to demonstrate that maternal experience of stressful conditions during pregnancy reduces AAM in the offspring through its effects on childhood BMI. Future research should consider the impact of AAM on other measures of reproductive ability.

  19. Timing of quizzes during learning: Effects on motivation and retention.

    Science.gov (United States)

    Healy, Alice F; Jones, Matt; Lalchandani, Lakshmi A; Tack, Lindsay Anderson

    2017-06-01

    This article investigates how the timing of quizzes given during learning impacts retention of studied material. We investigated the hypothesis that interspersing quizzes among study blocks increases student engagement, thus improving learning. Participants learned 8 artificial facts about each of 8 plant categories, with the categories blocked during learning. Quizzes about 4 of the 8 facts from each category occurred either immediately after studying the facts for that category (standard) or after studying the facts from all 8 categories (postponed). In Experiment 1, participants were given tests shortly after learning and several days later, including both the initially quizzed and unquizzed facts. Test performance was better in the standard than in the postponed condition, especially for categories learned later in the sequence. This result held even for the facts not quizzed during learning, suggesting that the advantage cannot be due to any direct testing effects. Instead the results support the hypothesis that interrupting learning with quiz questions is beneficial because it can enhance learner engagement. Experiment 2 provided further support for this hypothesis, based on participants' retrospective ratings of their task engagement during the learning phase. These findings have practical implications for when to introduce quizzes in the classroom. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  20. The Welfare Effects of Involuntary Part-time Work

    DEFF Research Database (Denmark)

    Borowczyk-Martins, Daniel; Lalé, Etienne

    2018-01-01

    Employed individuals in the USA are increasingly more likely to move to involuntarily part-time work than to unemployment. Spells of involuntary part-time work are different from unemployment spells: a full-time worker who takes on a part-time job suffers an earnings loss while remaining employed......, and is unlikely to receive income compensation from publicly provided insurance programmes. We analyse these differences through the lens of an incomplete-market, job-search model featuring unemployment risk alongside an additional risk of involuntary part-time employment. A calibration of the model consistent...... with US institutions and labour market dynamics shows that involuntary part-time work generates lower welfare losses relative to unemployment. This finding relies critically on the much higher probability to return to full-time employment from part-time work. We interpret it as a premium in access to full...

  1. Effects of time of day on shopping behavior.

    Science.gov (United States)

    Chebat, J C

    1999-04-01

    Shoppers interviewed in a shopping mall at different times of the day show different activities within the mall and attitudes toward the products. Prices also vary with the time of the day. These results can be explained in terms of shopping values and the related demographic characteristics of the population visiting the shopping center at different times of the day.

  2. Veterinary attitudes towards pre-pubertal gonadectomy of cats: a comparison of samples from New Zealand, Australia and the United Kingdom.

    Science.gov (United States)

    Farnworth, M J; Adams, N J; Seksel, K; Waran, N K; Beausoleil, N J; Stafford, K J

    2013-07-01

    To compare the attitudes and practices of a sample of veterinarians in New Zealand, Australia and the United Kingdom (UK) towards pre-pubertal gonadectomy of cats. Respondents' demographics were gathered using an electronic questionnaire distributed via professional veterinary associations in the target countries, as were minimum age at gonadectomy and typical age of puberty. Desirability of prepubertal gonadectomy was gauged using three response categories ('yes', 'no' or 'sometimes'), respondents were then able to justify the response given. Two-way Analyses of Variance (ANOVA) followed by post hoc Tukey HSD tests were used to test whether there were differences in minimum ages for gonadectomy within and between countries and between providers and non-providers of services to pounds (or animal welfare centres). Views on the desirability of prepubertal gonadectomy relative to demographics were explored using a Likelihood Ratio Test. The survey received 717 responses. Most respondents believed pre-pubertal gonadectomy was either entirely or 'sometimes' desirable (556/621), few thought it was undesirable (65/621). Minimum age at gonadectomy was significantly affected by country surveyed and provision or non-provision of services for pounds. Post hoc Tukey HSD analysis indicated the mean age of both spaying and castration (4.3 months) in the UK was significantly different from both Australia (spaying: 3.4 months, castration: 3.2 months) and New Zealand (spaying: 3.4 months, castration: 3.2 months) (all ppre- pubertal gonadectomy. Respondents from the UK were more likely to answer 'no' (p = 0.004) or 'sometimes' (p = 0.050) as compared to those from New Zealand or Australia. Females were more likely to respond with 'sometimes' as opposed to 'yes' than males. Reasons for considering pre-pubertal gonadectomy desirable or sometimes desirable focussed on reducing unwanted pregnancies and improving population control, as well as improving rates of adoption, owner

  3. Adult Height after Growth Hormone Treatment at Pubertal Onset in Short Adolescents Born Small for Gestational Age: Results from a Belgian Registry-Based Study

    Directory of Open Access Journals (Sweden)

    M. Thomas

    2018-01-01

    Full Text Available Objectives. Information on the efficacy of GH treatment in short SGA children starting their treatment in adolescence is limited. Therefore, adult height (AH, total height gain, and pubertal height gain were evaluated in short SGA children who started GH treatment at pubertal onset. Patient and Methods. Growth data of 47 short SGA adolescents (22 boys who started GH treatment at pubertal onset (PUB group were compared with results from 27 short SGA patients (11 boys who started GH therapy at least 1 year before pubertal onset (PrePUB group. Results. The PUB group achieved a mean (±SD total height gain of 0.8 ± 0.7 SDS and an AH of −2.5 ± 0.7 SDS after 4.1 ± 1.1 years of GH treatment with a dosage of 41.8 ± 8.4 μg/kg/day. These results were comparable with those in the PrePUB group, which was treated for a longer duration (5.8 ± 2.1 years, resulting in a total height gain of 1.1 ± 0.7 SDS and an AH of −2.1 ± 1.0 SDS. Multiple regression analysis showed a significantly lower height gain in pubertal patients, females, and patients weighing less at start of GH treatment. An AH above −2 SDS and above the parent-specific lower limit of height was, respectively, reached in 28% and 70% of PUB and 44% and 67% of PrePUB patients (NS. AH SDS was positively correlated with the height SDS at start of GH. Conclusions. Short SGA adolescents starting GH therapy at an early pubertal stage have a modest and variable height gain. A normal AH can be expected in one third of the patients, especially in those with a smaller height deficit at onset of GH treatment.

  4. Physical activity, sedentary time, and sleep and the association with inflammatory markers and adiponectin in 8- to 11-year-old Danish children

    DEFF Research Database (Denmark)

    Nielsen, Mette Søndergaard; Quist, Jonas Salling; Chaput, Jean-Philippe

    2016-01-01

    the association between accelerometer determined moderate-to-vigorous physical activity (MVPA), sedentary time, and sleep (7 days/8 nights) and fasting C-reactive protein (CRP), interleukin-6 (IL-6), and adiponectin in 806 school children. A sleep variability score was calculated. RESULTS: MVPA was negatively...... associated with adiponectin in boys and girls (Psleep duration, sedentary time, age, fat mass index (FMI), and pubertal status. Sedentary time was positively associated with adiponectin in boys and girls (both Psleep duration...... with adiponectin in boys independent of age, FMI, and pubertal status (PSleep duration variability was positively associated with CRP in girls independent of all covariates (P

  5. The timing of normal puberty and the age limits of sexual precocity

    DEFF Research Database (Denmark)

    Parent, Anne-Simone; Teilmann, Grete; Juul, Anders

    2003-01-01

    During the past decade, possible advancement in timing of puberty has been reported in the United States. In addition, early pubertal development and an increased incidence of sexual precocity have been noticed in children, primarily girls, migrating for foreign adoption in several Western European...

  6. The timing of normal puberty and the age limits of sexual precocity

    DEFF Research Database (Denmark)

    Parent, Anne-Simone; Teilmann, Grete; Juul, Anders

    2003-01-01

    During the past decade, possible advancement in timing of puberty has been reported in the United States. In addition, early pubertal development and an increased incidence of sexual precocity have been noticed in children, primarily girls, migrating for foreign adoption in several Western Europe...

  7. Association of Adiposity Genetic Variants With Menarche Timing in 92,105 Women of European Descent

    NARCIS (Netherlands)

    Fernández-Rhodes, L.; Demerath, E.W.; Cousminer, D.L.; Tao, R.; Dreyfus, J.G.; Esko, T.; Smith, A.V.; Gudnason, V.; Harris, T.B.; Launer, L.; McArdle, P.F.; Yerges-Armstrong, L.M.; Elks, C.E.; Strachan, D.P.; Kutalik, Z.; Vollenweider, P.; Feenstra, B.; Boyd, H.A.; Metspalu, A.; Mihailov, E.; Broer, L.; Zillikens, M.C.; Oostra, B.A.; van Duijn, C.M.; Lunetta, K.L.; Perry, J.R.; Murray, A.; Koller, D.L.; Lai, D.; Corre, T.; Toniolo, D.; Albrecht, E.; Stöckl, D.; Grallert, H.; Gieger, C.; Hayward, C.; Polasek, O.; Rudan, I.; Wilson, J.F.; He, C.; Kraft, P.; Hu, F.B.; Hunter, D.J.; Hottenga, J.J.; Willemsen, G.; Boomsma, D.I.; Byrne, E.M.; Martin, N.G.; Montgomery, G.W.; Warrington, N.M.; Pennell, C.E.; Stolk, L.; Visser, J.A.; Hofman, A.; Uitterlinden, A.G.; Rivadeneira, F.; Lin, P.; Fisher, S.L.; Bierut, L.J.; Crisponi, L.; Porcu, E.; Mangino, M.; Zhai, G.; Spector, T.D.; Buring, J.E.; Rose, L.M.; Ridker, P.M.; Poole, C.; Hirschhorn, J.N.; Murabito, J.M.; Chasman, D.I.; Widén, E.; North, K.E.; Ong, K.K.; Franceschini, N.

    2013-01-01

    Obesity is of global health concern. There are well-described inverse relationships between female pubertal timing and obesity. Recent genome-wide association studies of age at menarche identified several obesity-related variants. Using data from the ReproGen Consortium, we employed meta-analytical

  8. Effect of long construction times on utility financial requirements

    International Nuclear Information System (INIS)

    Francis, J.M.

    1981-01-01

    It is well-known that long construction times significantly increase the cost of an individual nuclear plant. Long construction times, however, are not confined to either a single plant or a single utility. Rather, they apparently occur in almost all nuclear plants currently under construction. The total financial requirement to complete the 82 nuclear plants currently under construction was assessed. The analysis was performed assuming a construction time of ten years in one case, and six years in another. It was found that decreasing the construction time from ten to six years will reduce the financial requirements of the utility industry by $89 billion

  9. Inferring Saving in Training Time From Effect Size Estimates

    National Research Council Canada - National Science Library

    Burright, Burke

    2000-01-01

    .... Students' time saving represents a major potential benefit of using them. This paper fills a methodology gap in estimating the students' timesaving benefit of asynchronous training technologies...

  10. The Welfare Effects of Involuntary Part-Time Work

    OpenAIRE

    Borowczyk-Martins, Daniel; Lalé, Etienne

    2016-01-01

    Employed individuals in the U.S. are increasingly more likely to work part-time involuntarily than to be unemployed. Spells of involuntary part-time work are different from unemployment spells: a full-time worker who takes on a part-time job suffers an earnings loss while remaining employed, and is unlikely to receive income compensation from publicly-provided insurance programs.We analyze these differences through the lens of an incomplete-market, job-search model featuring unemployment risk...

  11. Analysis of Time Discretization and its Effect on Simulation Processes

    Directory of Open Access Journals (Sweden)

    Gilbert-Rainer Gillich

    2006-10-01

    Full Text Available The paper presents the influence of time discretization on the results of simulations of technical systems. In this sense the systems are mod-eled using the SciLab/SCICOS environment, using different time inter-vals. Ulterior the processes are simulated and the results are com-pared.

  12. Effect of Individual Surgeons and Anesthesiologists on Operating Room Time

    NARCIS (Netherlands)

    van Eijk, Ruben P A; van Veen-Berkx, Elizabeth; Kazemier, Geert; Eijkemans, Marinus J C

    BACKGROUND:: Variability in operating room (OR) time causes overutilization and underutilization of the available ORs. There is evidence that for a given type of procedure, the surgeon is the major source of variability in OR time. The primary aim was to quantify the variability between surgeons and

  13. Effect of Retention Time on Biogas Production from Poultry ...

    African Journals Online (AJOL)

    A study was carried out on different retention times in the anaerobic fermentation of slurry from poultry droppings and cassava peels. The system adopted in this work was batch-type. Daily gas production fell slightly from 130 to 32 litres as retention time was increased from 10 to 40 days for poultry droppings. For cassava ...

  14. Effect of curing time on microstructure and mechanical strength ...

    Indian Academy of Sciences (India)

    The aim of this paper is to study the influence of curing time on the microstructure and mechanical strength development of alkali activated binders based on vitreous calcium aluminosilicate (VCAS). Mechanical strength of alkali activated mortars cured at 65 °C was assessed for different curing times (4–168 h) using 10 ...

  15. Design of TIME2 code: time dependent effects on Land 2 type repositories for Department of the Environment

    International Nuclear Information System (INIS)

    1985-07-01

    Design details for the proposed TIME2 computer code are presented for the purposes of information, planning and to serve as a guideline during code development. The TIME2 code will describe the long-term evolution of the environments of Land 2 type radioactive waste disposal sites (also known as 'time dependent effects'). Outlines are presented of code purpose and utilisation, specification and structure, input and output design, verification and validation, quality assurance and documentation. (author)

  16. Effect of prolonged mixing time on concrete properties

    International Nuclear Information System (INIS)

    Mohd Noorul Ikhsan Mohamed; Sidek, H.A.A.; Wahab, Z.A.

    2009-01-01

    The correlation between workability, compressive strength and mixing time of fresh concrete has been studied. The concrete samples used in the study are normal concrete of grade 30. The mix design of the concrete samples was estimated using software called Calcrete. Three concrete cubes of 150 mm size were cast immediately after mixing. The same grade of concrete was prepared with the mixing time of 30 minutes to 5 hours. All of the concrete samples were cured for 28 days under room temperature before they were compressed using a compression machine. Result shows that the compressive strength of concrete decreases when mixing time is increased. (author)

  17. RETENTION TIME EFFECT ON METAL REMOVAL BY PEAT COLUMNS

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, E

    2007-02-28

    The potential use of a peat bed to treat the H-12 Outfall discharge to bring it to new compliance limits was previously investigated and reported utilizing a 7 hour retention time. The influence of retention time (contact time) of water with peat moss on the removal of copper from the water was investigated under laboratory conditions using vertical flow peat moss columns. Reduction of the necessary retention time has a large influence on the design sizing of any peat bed that would be constructed to treat the H-12 discharge on a full scale basis. Retention times of 5 hours, 3 hours and 1 hour were tested to determine the copper removal by the peat columns using vertical flow. Water samples were collected after 4, 8, 12, and 16 water volumes had passed through the columns and analyzed for a suite of metals, with quantitative emphasis on copper. Laboratory results indicated that copper removal was very high at each of the 3 retention times tested, ranging from 99.6 % removal at 5 and 3 hours to 98.8% removal at 1 hour. All these values are much lower that the new compliance limit for the outfall. The results also indicated that most divalent metals were removed to their normal reporting detection limit for the analytical methods used, including zinc. Lead levels in the H-12 discharge used in this study were below PQL in all samples analyzed. While each of the retention times studied removed copper very well, there were indications that 1 hour is probably too short for an operational, long-term facility. At that retention time, there was about 6% compaction of the peat in the column due to the water velocity, and this may affect long term hydraulic conductivity of the peat bed. At that retention time, copper concentration in the effluent was higher than the other times tested, although still very low. Because of the potential compacting and somewhat reduced removal efficiency at a 1 hour retention time, it would be prudent to design to at least a 3 hour retention

  18. Finite correlation time effects in kinematic dynamo problem

    International Nuclear Information System (INIS)

    Schekochihin, A.A.; Kulsrud, R.M.

    2000-01-01

    One-point statistics of the magnetic fluctuations in kinematic regime with large Prandtl number and non delta-correlated in time advecting velocity field are studied. A perturbation expansion in the ratio of the velocity correlation time to the dynamo growth time is constructed in the spirit of the Kliatskin-Tatarskii functional method and carried out to first order. The convergence properties are improved compared to the commonly used van Kampen-Terwiel method. The zeroth-order growth rate of the magnetic energy is estimated to be reduced (in three dimensions) by approximately 40%. This reduction is quite close to existing numerical results

  19. The differential effects of full-time and part-time work status on breastfeeding.

    Science.gov (United States)

    Mandal, Bidisha; Roe, Brian Eric; Fein, Sara Beck

    2010-09-01

    Return to work is associated with diminished breastfeeding. Although more mothers breastfeed after returning to work compared to a decade ago, research has not documented the variations in breastfeeding initiation and duration based on full-time and part-time (less than 35h/week) work status. In this study, we clarify these differences. Longitudinal data from the Infant Feeding Practices Study II, collected between 2005 and 2007, for over 1400 mothers are used. In analyzing initiation, mother's work status was categorized by the expected number of hours she planned to work postpartum. In the duration model, work status was categorized based on the actual number of hours worked upon mother's return to employment after controlling for baby's age when she returned to work. Covariates in logistic and censored regressions included demographics, maternity leave, parity, past breastfeeding experience, hospital experience, and social support. Compared with expecting not to work, expecting to work Part-time work and increased amount of leave taken promote breastfeeding initiation and duration.

  20. The Effects of Time on Soil Behaviour and Pile Capacity

    DEFF Research Database (Denmark)

    Augustesen, Anders

    When designing pile foundations, static design equations, pile driving formulae, static loading tests or stress wave analyses can be employed to estimate the axial capacity of single piles. Both laboratory and field tests show that soil exhibits time-dependent behaviour. An important result...... based on a set of static loading tests. In the literature it is suggested that the pile capacity increases with the logarithm to time after installation which is confirmed in this thesis. In continuation of this, it is analysed whether the magnitude of the set-up is related to the properties of the clay...... circumstances (e.g. load specifications, length of pile, pile material). In order to evaluate the design methods for piles in clay, it is necessary to correct for time between pile driving and pile testing. Results of testing the calculation procedures against the available data by employing different time...

  1. Nonlinear effects on Turing patterns: Time oscillations and chaos

    KAUST Repository

    Aragó n, J. L.; Barrio, R. A.; Woolley, T. E.; Baker, R. E.; Maini, P. K.

    2012-01-01

    consequence, the patterns oscillate in time. When varying a single parameter, a series of bifurcations leads to period doubling, quasiperiodic, and chaotic oscillations without modifying the underlying Turing pattern. A Ruelle-Takens-Newhouse route to chaos

  2. The effect of Agrobacterium densities and inoculation times on gene ...

    African Journals Online (AJOL)

    admin

    2014-06-04

    Jun 4, 2014 ... rubber tree, genetic improvement has been very slow and time-consuming as the ..... Expression of human serum albumin in transgenic Hevea ... Identification of expression profiles of tapping panel dryness (TPD) associated ...

  3. Effect of emergency physician burnout on patient waiting times.

    Science.gov (United States)

    De Stefano, Carla; Philippon, Anne-Laure; Krastinova, Evguenia; Hausfater, Pierre; Riou, Bruno; Adnet, Frederic; Freund, Yonathan

    2018-04-01

    Burnout is common in emergency physicians. This syndrome may negatively affect patient care and alter work productivity. We seek to assess whether burnout of emergency physicians impacts waiting times in the emergency department. Prospective study in an academic ED. All patients who visited the main ED for a 4-month period in 2016 were included. Target waiting times are assigned by triage nurse to patients on arrival depending on their severity. The primary endpoint was an exceeded target waiting time for ED patients. All emergency physicians were surveyed by a psychologist to assess their level of burnout using the Maslach Burnout Inventory. We defined the level of burnout of the day in the ED as the mean burnout level of the physicians working that day (8:30 to the 8:30 the next day). A logistic regression model was performed to assess whether burnout level of the day was independently associated with prolonged waiting times, along with previously reported predictors. Target waiting time was exceeded in 7524 patients (59%). Twenty-six emergency physicians were surveyed. Median burnout score was 35 [Interquartile (24-49)]. A burnout level of the day higher than 35 was independently associated with an exceeded target waiting time (adjusted odds ratio 1.54, 95% confidence interval 1.39-1.70), together with previously reported predictors (i.e., day of the week, time of the day, trauma, age and daily census). Burnout of emergency physicians was independently associated with a prolonged waiting time for patients visiting the ED.

  4. Effects of Barium Concentration on Oropharyngeal Swallow Timing Measures

    OpenAIRE

    Stokely, Shauna L.; Molfenter, Sonja M.; Steele, Catriona M.

    2013-01-01

    Videofluoroscopy is commonly used for evaluating oropharyngeal swallowing but requires radiopaque contrast (typically barium). Prior studies suggest that some aspects of swallowing, including timing measures of oral and pharyngeal bolus transit, vary depending on barium concentration. The aim of our study was to identify timing differences in healthy swallowing between “thin” (40 % w/v concentration) and “ultrathin” (22 % w/v concentration) barium solutions. Twenty healthy adults (Ten women; ...

  5. Effects of barium concentration on oropharyngeal swallow timing measures.

    Science.gov (United States)

    Stokely, Shauna L; Molfenter, Sonja M; Steele, Catriona M

    2014-02-01

    Videofluoroscopy is commonly used for evaluating oropharyngeal swallowing but requires radiopaque contrast (typically barium). Prior studies suggest that some aspects of swallowing, including timing measures of oral and pharyngeal bolus transit, vary depending on barium concentration. The aim of our study was to identify timing differences in healthy swallowing between "thin" (40 % w/v concentration) and "ultrathin" (22 % w/v concentration) barium solutions. Twenty healthy adults (Ten women; mean age = 31 years) each performed a series of three noncued 5-ml swallows each of ultrathin and thin liquid barium solutions in videofluoroscopy. Timing measures were compared between barium concentrations using a mixed-model ANOVA. The measures of interest were stage transition duration, pharyngeal transit time, and duration of upper esophageal sphincter opening. Significant differences were observed in the timing measures of swallowing with respect to barium concentration. In all cases, longer durations were seen with the higher barium concentration. Barium concentration influences timing parameters in healthy swallowing, even between ultrathin and thin concentrations. Clinicians need to understand and control for the impact of different barium stimuli on swallowing physiology.

  6. Association of insulin-like growth factor-1 and IGF binding protein-3 with 25-hydroxy vitamin D in pre-pubertal and adolescent Indian girls.

    Science.gov (United States)

    Marwaha, Ramank K; Garg, M K; Gupta, Sushil; Ganie, Mohd Ashraf; Gupta, Nandita; Narang, Archna; Shukla, Manoj; Arora, Preeti; Singh, Annie; Chadha, Aditi; Mithal, Ambrish

    2018-03-28

    There is a high prevalence of vitamin D deficiency (VDD) in India. Molecular mechanisms suggest a strong relationship between vitamin D and growth factors. However, there is a paucity of literature with regard to a relationship between insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3) and vitamin D particularly in subjects with VDD. The objective of the study was to assess the relationship between growth factors and serum vitamin D-parathormone (PTH) status in school girls and study the impact of vitamin D supplementation on growth factors in pre-pubertal girls with VDD. Our study subjects were apparently healthy school girls aged 6-18 years. The baseline height, weight, body mass index (BMI), pubertal status, serum 25-hydroxy vitamin D (25OHD), PTH, IGF-1 and IGFBP-3 were assessed in 847 girls aged 6-18 years and in 190 pre-pubertal girls with VDD following supplementation. The mean age, BMI and serum 25OHD of girls were 11.5±3.2 years, 18.7±4.8 kg/m2 and 9.9±5.6 ng/mL, respectively. VDD was observed in 94.6% of girls. Unadjusted serum IGF-1 levels and IGF-1/IGFBP-3 molar ratio were significantly higher in girls with severe VDD as compared to girls with mild-to-moderate VDD. However, these differences disappeared when adjusted for age, height or sexual maturation. The serum IGF-1 and IGFBP-3 levels increased significantly post supplementation with vitamin D. There were no differences in serum IGF-1 levels and the IGF-1/IGFBP-3 molar ratio among VDD categories when adjusted for age, height and sexual maturation in girls. Vitamin D supplementation resulted in a significant increase in serum IGF-1 levels in VDD pre-pubertal girls.

  7. Associations of Birth Order with Early Adolescent Growth, Pubertal Onset, Blood Pressure and Size: Evidence from Hong Kong?s ?Children of 1997? Birth Cohort

    OpenAIRE

    Kwok, Man Ki; Leung, Gabriel M.; Schooling, C. Mary

    2016-01-01

    Background Birth order has been proposed as a cardiovascular risk factor, because the lower birth weight and greater infant weight gain typical of firstborns could programme metabolism detrimentally. Methods We examined the associations of birth order (firstborn or laterborn) with birth weight-for-gestational age, length/height and body mass index (BMI) z-scores during infancy, childhood, and puberty using generalized estimating equations, with age at pubertal onset using interval-censored re...

  8. The Differential Effects of Position, Velocity, and Acceleration Feedback on Motivation Over Time

    National Research Council Canada - National Science Library

    Watola, Daniel J

    2005-01-01

    .... Simple effects analyses indicated that participants' indicators of task motivation increased over time in the accelerating performance profile, but decreased over time in the decelerating performance profile...

  9. A Causal Contiguity Effect That Persists across Time Scales

    Science.gov (United States)

    Kilic, Asli; Criss, Amy H.; Howard, Marc W.

    2013-01-01

    The contiguity effect refers to the tendency to recall an item from nearby study positions of the just recalled item. Causal models of contiguity suggest that recalled items are used as probes, causing a change in the memory state for subsequent recall attempts. Noncausal models of the contiguity effect assume the memory state is unaffected by…

  10. Modeling the effects of binary mixtures on survival in time.

    NARCIS (Netherlands)

    Baas, J.; van Houte, B.P.P.; van Gestel, C.A.M.; Kooijman, S.A.L.M.

    2007-01-01

    In general, effects of mixtures are difficult to describe, and most of the models in use are descriptive in nature and lack a strong mechanistic basis. The aim of this experiment was to develop a process-based model for the interpretation of mixture toxicity measurements, with effects of binary

  11. Effects of time-dependent photoionization on interstellar pickup atoms

    International Nuclear Information System (INIS)

    Isenberg, P.A.; Lee, M.A.

    1995-01-01

    We present an analytical model for the density variations of interstellar pickup ions in the solar wind due to a time-dependent variation in the photoionization rate, our model predicts a pickup ion density enhancement lasting for a time of the order of the duration of the increase plus the solar wind convection time to the observation point. If the photoionization rate returns to its initial value, this enhancement is followed by a decreased pickup ion density resulting from a depleted interstellar neutral particle density. In the absence of further variations in the photoionization rate, the pickup ion density recovers on a time which scales as the radial position of the observation point divided by the inflow speed of the neutral particles. Gradual variations in the photoionization rate result in a pickup ion density which tends to track the ionization rate, though the density variations are smoothed and delayed in time due to the solar wind convection of ions picked up at points closer to the Sun. 27 refs., 4 figs

  12. The effect of increased CRA trip insertion times for TMI

    International Nuclear Information System (INIS)

    Irani, A.; Link, J.; Trikouos, N.

    1996-01-01

    In recent years, testing of control rod assembly (CRA) drop times at TMI has resulted in a few rods that have failed to meet the Technical Specification (TS) acceptance criteria of 1.66 seconds to 3/4 inserted. Crud deposition was determined to be the cause of the slow rod insertion times. Corrective actions included increasing lithium concentration and increasing the frequency and extent of exercising the control rod drive mechanisms. However, after one cycle of operation, it was determined that these measures were not fully successful in retarding the crud buildup. Consequently, the safety significance of rods potentially having a longer drop time than the TS limit was evaluated. The analyses in Chapter 14 of the TMI FSAR demonstrate the ability of the plant to mitigate the consequences of postulated accidents without undue hazard to the health and safety of the public. To determine the safety consequences of the longer rod drop times, a reanalysis of some limiting accidents had to be done using the RETRAN, RELAP5 and TRAC computer codes. The safety evaluation concluded that a 3.0 second rod drop time would be acceptable because all of the event acceptance criteria were met. A permanent resolution of the problem is the replacement of the existing thermal barriers with new open flow path thermal barriers. Thermal barriers on half the CRAs at TMI have been replaced to date

  13. EFFECTS OF ACOUSTIC STIMULATION ON BIOPHYSICAL PROFILE TESTING TIME

    Directory of Open Access Journals (Sweden)

    M. Pourissa

    2008-04-01

    Full Text Available Biophysical profile (BPP test is the most commonly used antenatal test of fetal well-being. Purpose of this study is determining the influence of acoustic stimulation (AS on BPP testing time. About 55 pregnant women at 35 to 42 weeks who referred to department of Obstetric & Gynecology at university of medical sciences, Tabriz, Iran, were selected randomly. We used abdominal ultrasound guidance to place buzzer like device with power of 110 dB at the skin surface of the maternal abdomen, close to the fetal head. BPP test performed and BPP mean testing time calculated before and after AS. Data compared and analyzed by paired t-test. The results showed that fetal AS reduces the overall mean testing time from 24 minutes to 5 minutes. This clinical application can be helpful in busy clinics when rapid assessment of fetal health is required.

  14. Effect of Time on Gypsum-Impression Material Compatibility

    Science.gov (United States)

    Won, John Boram

    The purpose of this study was to evaluate the compatibility of dental gypsum with three recently introduced irreversible hydrocolloid (alginate) alternatives. The test materials were Alginot® (Kerr™), Position Penta Quick® (3M ESPE™) and Silgimix ® (Sultan Dental™). The irreversible hydrocolloid impression material, Jeltrate Plus antimicrobial® (Dentsply Caulk™) served as the control. Materials and Methods: Testing of materials was conducted in accordance with ANSI/ADA Specification No. 18 for Alginate Impression Materials. Statistical Analysis: The 3-Way ANOVA test was used to analyze measurements between different time points at a significance level of (p Outcome: It was found that there was greater compatibility between gypsum and the alternative materials over time than the traditional irreversible hydrocolloid material that was tested. A statistically significant amount of surface change/incompatibility was found over time with the combination of the dental gypsum products and the control impression material (Jeltrate Plus antimicrobial®).

  15. Effect of the MCNP model definition on the computation time

    International Nuclear Information System (INIS)

    Šunka, Michal

    2017-01-01

    The presented work studies the influence of the method of defining the geometry in the MCNP transport code and its impact on the computational time, including the difficulty of preparing an input file describing the given geometry. Cases using different geometric definitions including the use of basic 2-dimensional and 3-dimensional objects and theirs combinations were studied. The results indicate that an inappropriate definition can increase the computational time by up to 59% (a more realistic case indicates 37%) for the same results and the same statistical uncertainty. (orig.)

  16. Time dependent density matrix theory and effective interaction

    Energy Technology Data Exchange (ETDEWEB)

    Tohyama, Mitsuru [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine

    1998-07-01

    A correlated ground state of {sup 16}O and an E2 giant resonance built on it are calculated using an extended version of the time-dependent Hartree-Fock theory called the time-dependent density-matrix theory (TDDM). The Skyrme force is used in the calculation of both a mean field and two-body correlations. It is found that TDDM gives reasonable ground-state correlations and a large spreading width of the E2 giant resonance when single-particle states in the continuum are treated appropriately. (author)

  17. Corrections for the combined effects of decay and dead time in live-timed counting of short-lived radionuclides

    International Nuclear Information System (INIS)

    Fitzgerald, R.

    2016-01-01

    Studies and calibrations of short-lived radionuclides, for example "1"5O, are of particular interest in nuclear medicine. Yet counting experiments on such species are vulnerable to an error due to the combined effect of decay and dead time. Separate decay corrections and dead-time corrections do not account for this issue. Usually counting data are decay-corrected to the start time of the count period, or else instead of correcting the count rate, the mid-time of the measurement is used as the reference time. Correction factors are derived for both those methods, considering both extending and non-extending dead time. Series approximations are derived here and the accuracy of those approximations are discussed. - Highlights: • Derived combined effects of decay and dead time. • Derived for counting systems with extending or non-extending dead times. • Derived series expansions for both midpoint and decay-to-start-time methods. • Useful for counting experiments with short-lived radionuclides. • Examples given for "1"5O, used in PET scanning.

  18. Effect of Retention Time on Biogas Production from Poultry ...

    African Journals Online (AJOL)

    JPC

    Daily gas production fell slightly from 130 to 32 litres as retention time was ... The continuing energy crisis has reawakened interest in the anaerobic ... and hydrogen sulfide (H2S2): 0.3 vol.%. ..... Nigerian Journal of Solar Energy 15: 80 – 85.

  19. Effects of tempo and timing of simple musical rhythms

    NARCIS (Netherlands)

    Repp, B.H.; Windsor, W.L.; Desain, P.W.M.

    2002-01-01

    In this study we investigated whether and how the timing of musical rhythms changes with tempo. Twelve skilled pianists played a monophonic 8-bar melody in 21 different rhythmic versions at 4 different tempi. Within bars, the rhythms represented all possible ordered pairs and triplets of note values

  20. Effect of fibrinolysis inhibitors on survival time of irradiated rats

    International Nuclear Information System (INIS)

    Smok, W.

    1988-01-01

    The possibilities of alleviation of the gastrointestinal syndrome of acute radiation sickness by modification of haemorrhagic diathesis using EACA and traskolan were studied. A significant prolongation of the mean survival time was obtained in the irradiated rats treated with EACA. 7 tabs., 10 refs. (author)