Childhood obesity and adolescent follow-up depressive symptoms: exploring a moderated mediation model of body esteem and gender.

Obesity is a well-recognized risk factor for adolescent depressive symptoms, but mediating mechanisms of this association have scarcely been studied. This study is unique in examining an indirect pathway of this link via body esteem (BE) prospectively from childhood (8-12 years) to adolescence (13-18 years). In addition, potential gender moderation was examined. This study utilized data from a case-control study comparing 100 children with and without obesity matched on important confounders (age, gender, and socioeconomic status). Our findings provide support for the mediating role of BE in the link between childhood weight status and adolescent depressive symptoms at a 5-year follow-up. This mediation effect did not differ between boys and girls. The findings suggest the relevance of specifically targeting children's BE in preventive intervention programs among children with obesity to prevent future mental health problems.

Development and preliminary validation of the Adolescent Food Parenting Questionnaire: Parent and adolescent version.

Suitable instruments for measuring Food Parenting Practices (FPP) among adolescents and their parents that also measure the perception of adolescents about their parent's FPP are rare. The current study describes the development and preliminary testing of a short 16-item Adolescent Food Parenting Questionnaire (AFPQ) for parents (AFPQ-p) and adolescents (AFPQ-a) that may enable future large-scale research on potentially eminent parent-child FPP discrepancy. Participants included 381 parents (73.8 % mothers; Mage 45.9, 26.2% fathers; Mage 49.1) and their adolescent children (aged 12-16) who participated in the Dutch "G(F)OOD together" study. Most parents finished higher professional education (mothers: 44.3 %; fathers: 34.4 %) and performed a paid job of 32 h per week or more (mothers: 22.1 %; fathers: 60.0 %). The theoretical framework of Vaughn (2016) was leading in the development of the AFPQ. Exploratory factor analysis (EFA) was performed on a random split sample of parent-adolescent dyads and confirmatory factor analysis (CFA) was performed on the other half. The EFA in both parent and adolescent samples resulted in a clear 5 factor solution explaining 61.6 % (AFPQ-p) and 64.2 % (AFPQ-a) of the variance respectively, representing the factors Autonomy Support (α = 0.79/.82), Coercive Control (α = 0.85/.83), Snack Structure (α = 0.79/75), Healthy Structure (α = 0.78/74) and Modelling (α = 0.69/85). CFA confirmed good model fit for the AFPQ-p and the AFPQ-a. Associations with adolescent self-reported food intake were in the expected direction, confirming the preliminary convergent validity of the instrument among a moderate to highly educated group of parent-adolescent dyads. Although the AFPQ provides a promising short instrument, future research in more diverse samples is needed to build evidence on the instrument's psychometric characteristics in other groups.

Is the Prospective Link between Parental Stress and Adolescent Snack Intake or Weight Outcome Mediated by Food Parenting Practices?

Parental stress may influence adolescents' food intake and weight development over time, however, it is largely unknown why this is the case. This study examines whether the link between parental stress and adolescents' snack intake and weight outcome is mediated by food parenting practices (FPPs). Participants included 400 parents and their adolescent children (aged 12-16) who completed questionnaires. The Perceived Stress Scale (PSS) was used to assess parental general stress levels and the Adolescent Food Parenting Questionnaire (AFPQ) to assess FPPs. Multiple mediation analyses with parallel mediators were performed, with parental general stress as an independent variable and adolescent snack intake and zBMI as dependent variables. FPPs (autonomy support, coercive control, modeling, healthy structure, snack structure) were entered as mediators in the model, adjusted for covariates. Autonomy support mediated the link between parental general stress and adolescent savory snack and sweet snack intake at follow-up. Parents who reported higher stress levels provided less autonomy support, which resulted in more adolescent snacking. None of the other FPPs mediated any link between parental stress and intake or weight outcome, and no significant indirect effects were observed with zBMI as an outcome variable. Further research should replicate this finding and may further examine underlying mechanisms.

The longitudinal link between mothers' and adolescents' snacking: The moderating role of television viewing.

A large proportion of adolescents eats too many energy-dense snacks, which is detrimental for their current and future health. To understand how to promote healthy dietary behaviors in adolescents, we need to identify factors that affect their snacking. While previous cross-sectional work has shown mother-child similarities in eating behavior, longitudinal studies are lacking. Hence, the first aim of this study was to examine whether maternal snacking predicted changes in adolescents' snacking over time. A second aim was to examine whether adolescents' television viewing magnified the strength of this longitudinal association. Television viewing may increase the motivation to eat the snacks consumed by mothers later on, for example through food advertisement exposure and mindless eating. To address both aims, 2051 adolescents (Mage baseline = 13.81; 51.5% boys) were asked to report on their snacking and television viewing three times, with intervals of one year. Moreover, a subsample of mothers of adolescents (N = 1080) reported on their snacking at baseline as well. The results indicate that maternal snacking indeed predicts adolescents' snacking over time and that this effect is more pronounced among adolescents who watch a great amount of television. These findings attest to the importance of mothers in forming adolescents' snacking, not only concurrently but also prospectively. Additionally, this study highlights the relevance of assessing other home environmental factors that may influence maternal effects on their children's snacking.

RankProd 2.0: a refactored bioconductor package for detecting differentially expressed features in molecular profiling datasets.

MOTIVATION: The Rank Product (RP) is a statistical technique widely used to detect differentially expressed features in molecular profiling experiments such as transcriptomics, metabolomics and proteomics studies. An implementation of the RP and the closely related Rank Sum (RS) statistics has been available in the RankProd Bioconductor package for several years. However, several recent advances in the understanding of the statistical foundations of the method have made a complete refactoring of the existing package desirable. RESULTS: We implemented a completely refactored version of the RankProd package, which provides a more principled implementation of the statistics for unpaired datasets. Moreover, the permutation-based P -value estimation methods have been replaced by exact methods, providing faster and more accurate results. AVAILABILITY AND IMPLEMENTATION: RankProd 2.0 is available at Bioconductor ( https://www.bioconductor.org/packages/devel/bioc/html/RankProd.html ) and as part of the mzMatch pipeline ( http://www.mzmatch.sourceforge.net ). CONTACT: rainer.breitling@manchester.ac.uk. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Exact p-values for pairwise comparison of Friedman rank sums, with application to comparing classifiers.

BACKGROUND: The Friedman rank sum test is a widely-used nonparametric method in computational biology. In addition to examining the overall null hypothesis of no significant difference among any of the rank sums, it is typically of interest to conduct pairwise comparison tests. Current approaches to such tests rely on large-sample approximations, due to the numerical complexity of computing the exact distribution. These approximate methods lead to inaccurate estimates in the tail of the distribution, which is most relevant for p-value calculation. RESULTS: We propose an efficient, combinatorial exact approach for calculating the probability mass distribution of the rank sum difference statistic for pairwise comparison of Friedman rank sums, and compare exact results with recommended asymptotic approximations. Whereas the chi-squared approximation performs inferiorly to exact computation overall, others, particularly the normal, perform well, except for the extreme tail. Hence exact calculation offers an improvement when small p-values occur following multiple testing correction. Exact inference also enhances the identification of significant differences whenever the observed values are close to the approximate critical value. We illustrate the proposed method in the context of biological machine learning, were Friedman rank sum difference tests are commonly used for the comparison of classifiers over multiple datasets. CONCLUSIONS: We provide a computationally fast method to determine the exact p-value of the absolute rank sum difference of a pair of Friedman rank sums, making asymptotic tests obsolete. Calculation of exact p-values is easy to implement in statistical software and the implementation in R is provided in one of the Additional files and is also available at http://www.ru.nl/publish/pages/726696/friedmanrsd.zip .

The Non-uniqueness Property of the Intrinsic Estimator in APC Models.

This article explores an important property of the intrinsic estimator that has received no attention in literature: the age, period, and cohort estimates of the intrinsic estimator are not unique but vary with the parameterization and reference categories chosen for these variables. We give a formal proof of the non-uniqueness property for effect coding and dummy variable coding. Using data on female mortality in the United States over the years 1960-1999, we show that the variation in the results obtained for different parameterizations and reference categories is substantial and leads to contradictory conclusions. We conclude that the non-uniqueness property is a new argument for not routinely applying the intrinsic estimator.

A fast algorithm for determining bounds and accurate approximate p-values of the rank product statistic for replicate experiments.

BACKGROUND: The rank product method is a powerful statistical technique for identifying differentially expressed molecules in replicated experiments. A critical issue in molecule selection is accurate calculation of the p-value of the rank product statistic to adequately address multiple testing. Both exact calculation and permutation and gamma approximations have been proposed to determine molecule-level significance. These current approaches have serious drawbacks as they are either computationally burdensome or provide inaccurate estimates in the tail of the p-value distribution. RESULTS: We derive strict lower and upper bounds to the exact p-value along with an accurate approximation that can be used to assess the significance of the rank product statistic in a computationally fast manner. The bounds and the proposed approximation are shown to provide far better accuracy over existing approximate methods in determining tail probabilities, with the slightly conservative upper bound protecting against false positives. We illustrate the proposed method in the context of a recently published analysis on transcriptomic profiling performed in blood. CONCLUSIONS: We provide a method to determine upper bounds and accurate approximate p-values of the rank product statistic. The proposed algorithm provides an order of magnitude increase in throughput as compared with current approaches and offers the opportunity to explore new application domains with even larger multiple testing issue. The R code is published in one of the Additional files and is available at http://www.ru.nl/publish/pages/726696/rankprodbounds.zip .

The exact probability distribution of the rank product statistics for replicated experiments.

The rank product method is a widely accepted technique for detecting differentially regulated genes in replicated microarray experiments. To approximate the sampling distribution of the rank product statistic, the original publication proposed a permutation approach, whereas recently an alternative approximation based on the continuous gamma distribution was suggested. However, both approximations are imperfect for estimating small tail probabilities. In this paper we relate the rank product statistic to number theory and provide a derivation of its exact probability distribution and the true tail probabilities.

Social coping by masking? Parental support and peer victimization as mediators of the relationship between depressive symptoms and expressive suppression in adolescents.

Expressive suppression is regarded as a generally ineffective emotion regulation strategy and appears to be associated with the development of depressive symptoms among adolescents. However, the mechanisms linking suppression to depressive symptoms are not well understood. The main aim of this study was to examine two potential mediators of the prospective relationship from depressive symptoms to expressive suppression among adolescents: parental support and peer victimization. Structural equation modelling was used to construct a three-wave cross-lagged model (n = 2,051 adolescents, 48.5 % female, at baseline; 1,465 with data at all three time points) with all possible longitudinal linkages. Depressive symptoms preceded decreases in perceived parental support 1 year later. Decreases in parental support mediated the relationship between depressive symptoms and increases in expressive suppression over a 2-year period. Multi-group analyses show that the mediation model tested was significant for girls, but not for boys. No evidence for other mediating models was found. Although initial suppression preceded increases in depressive symptoms 1 year later, we did not find any evidence for the reversed link from suppression to depressive symptoms. Clear evidence for a reciprocal relationship between depressive symptoms and parental support was found. However, only limited and inconsistent support was found for a reciprocal relationship between depressive symptoms and peer victimization. Finally, although some evidence for a unidirectional relationship from parental support to increases in suppression was found, no significant prospective relationship was found between peer victimization and suppression. The implications of our clear results for parental support, and mostly lacking results for peer victimization, are discussed.

Over my dead body: body donation and the rise in donor registrations in The Netherlands.

In The Netherlands, the number of body donor registrations has been increasing for several years. Body donors are people who register at an anatomical institute to donate their entire body, after death, for scientific education and research. Although only 0.1% of the Dutch population is registered as a body donor, this is sufficient to realize the anatomical demand of about 650 bodies annually. Due to the recent rise of registrations many anatomical institutes have (temporarily) stopped registering new donors to prevent a surplus of bodies. Based on a large body donor survey (n=759) and in-depth anthropological interviews with 20 body donors, we try to give an explanation for the rising registration numbers. We argue that the choice for body donation in contemporary, individualized Dutch society is an autonomous way to give meaning and sense to life and death outside the framework of institutionalized religion.

Interviewer BMI effects on under- and over-reporting of restrained eating: evidence from a national Dutch face-to-face survey and a postal follow-up.

OBJECTIVES: To determine the effect of interviewer BMI on self-reported restrained eating in a face-to-face survey and to examine under- and over-reporting using the face-to face study and a postal follow-up. METHODS: A sample of 1,212 Dutch adults was assigned to 98 interviewers with different BMI who administered an eating questionnaire. To further evaluate misreporting a mail follow-up was conducted among 504 participants. Data were analyzed using two-level hierarchical models. RESULTS: Interviewer BMI had a positive effect on restrained eating. Normal weight and pre-obese interviewers obtained valid responses, underweight interviewers stimulated under-reporting whereas obese interviewers triggered over-reporting. CONCLUSION: In face-to-face interviews self-reported dietary restraint is distorted by interviewer BMI. This result has implications for public health surveys, the more so given the expanding obesity epidemic.

Weather conditions and voter turnout in Dutch national parliament elections, 1971-2010.

While conventional wisdom assumes that inclement weather on election day reduces voter turnout, there is remarkably little evidence available to support truth to such belief. This paper examines the effects of temperature, sunshine duration and rainfall on voter turnout in 13 Dutch national parliament elections held from 1971 to 2010. It merges the election results from over 400 municipalities with election-day weather data drawn from the nearest weather station. We find that the weather parameters indeed affect voter turnout. Election-day rainfall of roughly 25 mm (1 inch) reduces turnout by a rate of one percent, whereas a 10-degree-Celsius increase in temperature correlates with an increase of almost one percent in overall turnout. One hundred percent sunshine corresponds to a one and a half percent greater voter turnout compared to zero sunshine.

Anatomist on the dissecting table? Dutch anatomical professionals' views on body donation.

Anatomical professionals know better than anyone else that donated bodies are a valuable asset to anatomical science and medical education. They highly value voluntary donations, since a dearth of bodies negatively affects their profession. With this in mind, we conducted a survey (n = 54) at the 171st scientific meeting of the Dutch Anatomical Society in 2009 to see to what extent anatomical professionals are willing to donate their own body. The results reveal that none of the survey participants are registered as a whole body donor and that only a quarter of them would consider the possibility of body donation. We argue that the two main constraints preventing Dutch anatomical professionals from donating their own body are their professional and their social environments. In contrast to the absence of registered body donors, half of the anatomical professionals are registered as an organ donor. This figure far exceeds the proportion of registered organ donors among the general Dutch population.

Weather conditions and political party vote share in Dutch national parliament elections, 1971-2010.

Inclement weather on election day is widely seen to benefit certain political parties at the expense of others. Empirical evidence for this weather-vote share hypothesis is sparse however. We examine the effects of rainfall and temperature on share of the votes of eight political parties that participated in 13 national parliament elections, held in the Netherlands from 1971 to 2010. This paper merges the election results for all Dutch municipalities with election-day weather observations drawn from all official weather stations well distributed over the country. We find that the weather parameters affect the election results in a statistically and politically significant way. Whereas the Christian Democratic party benefits from substantial rain (10 mm) on voting day by gaining one extra seat in the 150-seat Dutch national parliament, the left-wing Social Democratic (Labor) and the Socialist parties are found to suffer from cold and wet conditions. Cold (5°C) and rainy (10 mm) election day weather causes the latter parties to lose one or two parliamentary seats.

Personality and motivation for body donation.

BACKGROUND: This study examines the relationship between motivation for body donation to science and personality characteristics using a body donor survey (N=759) conducted by the University Medical Centre Groningen (UMCG) in The Netherlands. The survey expands on anthropological studies that suggest an association between donor motivation and personality. METHODS: A structural equation model was used to investigate the relationship between personality and motivation for body donation. FINDINGS: The results show that, compared to society at large, body donors have a similar spectrum of personality characteristics. However, we found statistically significant positive relationships between donor motivation and Big Five personality traits. Together the personality traits explain between 5% and 15% of the variance in motivation for body donation. CONCLUSIONS: We argue that donor campaigns should not focus solely on altruistic motives, but should include the aspect of possible personal achievement by the donor. This is a fruitful starting point for approaching potential donors and anticipating their needs.