Investigating general and specific links from adolescents’ perceptions of ecological assets to their civic actions

Civic engagement is an important marker of thriving among adolescents, and more research is needed that clarifies the ecological assets (positive supports across settings) that foster youth civic engagement. Simultaneously modeling associations between multiple ecological assets and civic behaviors can provide a nuanced view of the way adolescents’ ecological assets relate to distinct forms of civic engagement. To advance positive youth development theory, we used a bifactor modeling approach to examine general and specific ecological asset factors in relation to volunteering, conventional political, online political, and informal helping behaviors. In a large ethnically diverse sample of adolescents, the general ecological asset factor was positively associated with informal helping only. Classroom civic learning opportunities were positively associated with volunteering, conventional, and online political behaviors. Family political discussions were positively associated with conventional and online political behaviors. Our study suggests that civic engagement should be understood multidimensionally and that broad and specific ways of conceptualizing ecological assets have merit for understanding different types of youth civic engagement.     

Extracurricular Activity Participation and the Acquisition of Developmental Assets: Differences Between Involved and Noninvolved Canadian High School Students

In order to prepare students for adulthood and responsible citizenship, most high schools offer extracurricular activities designed to facilitate the learning of a wide range of competencies. The purpose of this study was to examine how participation in a single or a combination of extracurricular school activities for high school students may impact both their developmental outcomes and their level of school engagement. Results indicated differences between youth who participated in a combination of both sport and nonsport activities as well as sport only activities compared to youth not involved in extracurricular activities on a number of developmental assets and school engagement. It is recommended that parents and adult leaders encourage and support students in their involvement in various extracurricular activities, including high school sport, in order to facilitate positive youth development.     

Structural Relations Among Spirituality,Religiosity, and Thriving in Adolescence

Using the randomly selected subsample of 1,000 youth (472 boys, M age = 12.2 years, SD = 1.5; 528 girls, M age = 12.1 years, SD = 1.4) drawn by Dowling, Getsdottir, Anderson, von Eye, and Lerner (in press) from a Search Institute (1984) archival data set, Young Adolescents and Their Parents (YAP), this research employed structural equation modeling procedures to appraise the structural relations among second-order factors of religiosity, spirituality, and thriving. Three hierarchically related models were tested: The first model was a complete mediation model that involved a direct effect of spirituality on thriving and an indirect effect of spirituality on thriving, mediated by religiosity, the second model only consisted of the mediated effect, and the third model only consisted of the direct effects of spirituality on thriving and religiosity on thriving. Consistent with expectations, the complete mediation model provided reasonably good fit to the data and was significantly better than either of the alternative models. The importance of the findings reported here for the future study of youth thriving using either the YAP data set or new, longitudinal studies is discussed.     

Differential evolvability along lines of least resistance of upper and lower molars in island house mice

Variation within a population is a key feature in evolution, because it can increase or impede response to selection, depending on whether or not the intrapopulational variance is correlated to the change under selection. Hence, main directions of genetic variance have been proposed to constitute "lines of least resistance to evolution" along which evolution would be facilitated. Yet, the screening of selection occurs at the phenotypic level, and the phenotypic variance is not only the product of the underlying genetic variance, but also of developmental processes. It is thus a key issue for interpreting short and long term evolutionary patterns to identify whether main directions of phenotypic variance indeed constitute direction of facilitated evolution, and whether this is favored by developmental processes preferably generating certain phenotypes. We tackled these questions by a morphometric quantification of the directions of variance, compared to the direction of evolution of the first upper and lower molars of wild continental and insular house mice. The main phenotypic variance indeed appeared as channeling evolution between populations. The upper molar emerged as highly evolvable, because a strong allometric component contributed to its variance. This allometric relationship drove a repeated but independent evolution of a peculiar upper molar shape whenever size increased. This repeated evolution, together with knowledge about the molar development, suggest that the main direction of phenotypic variance correspond here to a "line of least developmental resistance" along which evolution between population is channeled.     

When and What Parents Tell Children About Race: An Examination of Race-Related Socialization Among African American Families

This article describes a developmental systems approach to applied developmental science (ADS), which provides a framework to design and evaluate technology-rich programs that promote positive development by emphasizing the strengths and assets of young people instead of focusing on diminishing or preventing risk-taking behaviors. Until now, most of the psychoeducational programs conceived within the ADS model have not focused on the role of new technologies in young people's lives. This absence is particularly striking given that, in today's world, new technologies play an important role in different areas of the lives of young people, such as education, entertainment, socialization, and communication. This article presents the concept of identity construction environments (ICE), an interdisciplinary model that proposes guidelines to design and study new technologies purposefully created to promote positive youth development (PYD). Two types of ICE have been developed: one focusing on stand-alone technologies for learning, such as the Zora virtual city; and the other focusing on an approach for developing technologically rich learning contexts, such as the Project Inter-Actions robotics workshops. This article presents both examples of ICE and describes how their design fosters the 6 components of PYD. Initial findings from pilot studies conducted with very different populations of youth engaged in both types of ICE—such as young children, adolescents, and chronically ill children—are presented.     

Local Distributions of Wealth to Describe Health Inequalities in India: A New Approach for Analyzing Nationally Representative Household Survey Data, 1992–2008

Background

Worse health outcomes including higher morbidity and mortality are most often observed among the poorest fractions of a population. In this paper we present and validate national, regional and state-level distributions of national wealth index scores, for urban and rural populations, derived from household asset data collected in six survey rounds in India between 1992–3 and 2007–8. These new indices and their sub-national distributions allow for comparative analyses of a standardized measure of wealth across time and at various levels of population aggregation in India.

Methods

Indices were derived through principal components analysis (PCA) performed using standardized variables from a correlation matrix to minimize differences in variance. Valid and simple indices were constructed with the minimum number of assets needed to produce scores with enough variability to allow definition of unique decile cut-off points in each urban and rural area of all states.

Results

For all indices, the first PCA components explained between 36% and 43% of the variance in household assets. Using sub-national distributions of national wealth index scores, mean height-for-age z-scores increased from the poorest to the richest wealth quintiles for all surveys, and stunting prevalence was higher among the poorest and lower among the wealthiest. Urban and rural decile cut-off values for India, for the six regions and for the 24 major states revealed large variability in wealth by geographical area and level, and rural wealth score gaps exceeded those observed in urban areas.

Conclusions

The large variability in sub-national distributions of national wealth index scores indicates the importance of accounting for such variation when constructing wealth indices and deriving score distribution cut-off points. Such an approach allows for proper within-sample economic classification, resulting in scores that are valid indicators of wealth and correlate well with health outcomes, and enables wealth-related analyses at whichever geographical area and level may be most informative for policy-making processes.     

Discussion: Three Ways to Misunderstand Developmental Systems Theory

Developmental systems theory (DST) is a general theoretical perspective on development, heredity and evolution. It is intended to facilitate the study of interactions between the many factors that influence development without reviving `dichotomous' debates over nature or nurture, gene or environment, biology or culture. Several recent papers have addressed the relationship between DST and the thriving new discipline of evolutionary developmental biology (EDB). The contributions to this literature by evolutionary developmental biologists contain three important misunderstandings of DST.     

Youth BMI Trajectories: Evidence From the NLSY97

We examined heterogeneity in BMI trajectory classes among youth and variables that may be associated with trajectory class membership. We used data from seven rounds (1997–2003) of the 1997 National Longitudinal Survey of Youth (NLSY97), a nationally representative, longitudinal survey of people born between 1980 and 1984 who were living in the United States in 1997. The analyses were based on an accelerated longitudinal design. General growth mixture modeling implemented in Mplus (version 4.1) was used to identify subtypes of youth BMI growth trajectories over time. Four distinct youth BMI trajectories were identified. Class 1 includes youth at high risk for becoming obese by young adulthood (at age 12 and 23, ～67 and 90%, respectively, are classified as obese, and almost 72% will have had a BMI ≥ 40 at some time during this developmental period). Class 2 includes youth at moderate‐to‐high risk (at age 12 and 23, ～55 and 68%, respectively, are classified as obese). Class 3 includes youth at low‐to‐moderate risk (i.e., at age 12 and 23, ～8 and 27%, respectively, are classified as obese). Class 4 includes youth at low risk (few of these youth are obese at any age during this developmental period). These results highlight the importance of considering heterogeneity in BMI growth among youth and early interventions among those most at risk of the adverse health consequences of excess weight.     

Asthma and Maternal Body Mass Index Are Related to Pediatric Body Mass Index and Obesity: Results from the Third National Health and Nutrition Examination Survey

Objective: Clinical research has shown an increased prevalence of obesity in children with asthma. This study was designed to assess the relationship between asthma and pediatric body mass index (BMI) in a national database and to examine factors that may modify this relationship. Design: The cross‐sectional relationship between asthma and pediatric BMI and obesity (BMI ≥ 85th percentile) was studied. Variables that may influence the relationship between asthma and pediatric BMI, such as race/ethnicity and television watching were included in the model for the total sample. A smaller sample of 3009 white and African American youth were studied in regression models including maternal BMI. Study Population: A nationally representative crosssectional sample of 5154 children and adolescents of 6 to 16 years of age from the Third National Health And Nutrition Examination Survey. Results: In the full sample, asthma and television watching were related to BMI, accounting for 3% of the variance in BMI. When maternal BMI was included in the nonHispanic sample, television watching, maternal BMI, and the interaction of maternal BMI and asthma were related to youth BMI, accounting for 15% of the variance. The standardized BMI z‐score for those youth without asthma and no maternal obesity was 0.06, which increased to 0.33 if the youth had asthma, to 0.70 if the youth did not have asthma but the mother was obese, and to 1.71 if the youth had asthma and the mother was obese. Asthma, television watching, and maternal BMI were independent predictors of youth obesity. Conclusions: BMI and prevalence of obesity is higher in youth with asthma. Pediatric BMI, but not obesity, is also related to the interaction of asthma and maternal BMI in white and African American youth. Comorbidity of asthma and obesity may complicate treatment of either condition, and prevention of obesity should be encouraged for asthmatic children.     

Cranial growth in Homo erectus: how credible are the Ngandong juveniles?

Confusion exists regarding the developmental ages of numerous Asian and southeast Asian Homo erectus fossils because of Weidenreich's contention that Pithecanthropus fused its sutures prematurely relative to H. sapiens. I reevaluate the cranial developmental ages of the Ngandong “juveniles” (2, 5, 8, 9) based on a series of indicators of youth (superstructure development, suture development/fusion, and cranial thickness) and cranial contours. The Ngandong juveniles are compared with H. sapiens adults (n = 281) and subadults (n = 81) and with Ngandong and other H. erectus adults (n = 20) and subadults (n = 4). Cranial contours are assessed using bivariate plots of arc vs. chord measurements. All indicators suggest that Ngandong 5 and 9 are adults, whereas Ngandong 8 is an older juvenile or young adult and Ngandong 2 is a juvenile with a developmental age range of greater than 6 and less than 11 years. In addition, adult cranial contours and the pattern of contour development are similar between Ngandong adults and other H. erectus adults. There is nothing in the cranial contour data to suggest that Ngandong is, despite a relatively large brain, transitional in vault shape between H. erectus and H. sapiens. Am J Phys Anthropol 108:223–236, 1999. © 1999 Wiley-Liss, Inc.     

Testing the rate isomorphy hypothesis using five statistical methods

Abstract Organisms are said to be in developmental rate isomorphy when the proportions of developmental stage durations are unaffected by temperature. Comprehensive stage‐specific developmental data were generated on the cabbage beetle, Colaphellus bowringi Baly (Coleoptera: Chrysomelidae), at eight temperatures ranging from 16°C to 30°C (in 2°C increments) and five analytical methods were used to test the rate isomorphy hypothesis, including: (i) direct comparison of lower developmental thresholds with standard errors based on the traditional linear equation describing developmental rate as the linear function of temperature; (ii) analysis of covariance to compare the lower developmental thresholds of different stages based on the Ikemoto‐Takai linear equation; (iii) testing the significance of the slope item in the regression line of versus temperature, where p is the ratio of the developmental duration of a particular developmental stage to the entire pre‐imaginal developmental duration for one insect or mite species; (iv) analysis of variance to test for significant differences between the ratios of developmental stage durations to that of pre‐imaginal development; and (v) checking whether there is an element less than a given level of significance in the p‐value matrix of rotating regression line. The results revealed no significant difference among the lower developmental thresholds or among the aforementioned ratios, and thus convincingly confirmed the rate isomorphy hypothesis.     

Impact of developmental variance on behavior of models for insect populations I. Models for populations with unrestricted growth

The concept of developmental variance is discussed with reference to its use in models for insect populations. When included in a model, developmental variance is typically used to describe the variation of developmental periods among individuals. However, its presence in a model can also have indirect impact on survival and fertility schedules. This impact can lead to significant changes in population growth rates and generation times. These relationships between developmental variance and population growth in models are quantified and discussed.     

Tobacco, alcohol and illicit drug use among Aboriginal youth living off-reserve: results from the Youth Smoking Survey

Background

Despite the high prevalence of smoking among Aboriginal youth, there is a paucity of research related to tobacco use and other risk behaviours among Aboriginal youth living off-reserve in Canada. We used data from the national Youth Smoking Survey to characterize non-traditional tobacco use, exposure to second-hand smoke, and alcohol and drug use among Aboriginal youth living off-reserve. We examined whether these youth were at increased health risk compared with non-Aboriginal youth.

Methods

We examined cigarette smoking behaviour, use of other tobacco products, use of alcohol and other drugs, and exposure to second-hand smoke among 2620 Aboriginal youth living off-reserve and 26 223 non-Aboriginal youth in grades 9 to 12 who participated in the 2008/09 Youth Smoking Survey.

Results

The prevalence of current smoking among the Aboriginal youth was more than double that among non-Aboriginal youth (24.9% v. 10.4%). Aboriginal youth also had a higher prevalence of regular exposure to second-hand smoke at home (37.3% v. 19.7%) and in cars (51.0% v. 30.3%). Aboriginal youth were more likely than non-Aboriginal youth to be current smokers, to be regularly exposed to second-hand smoke, to have tried marijuana and other illicit drugs, and to engage in binge drinking. They were less likely than non-Aboriginal youth to have tried to quit smoking.

Interpretation

Current national estimates of smoking, and alcohol and illicit drug use among youth underestimate the prevalence of these behaviours among Aboriginal youth living off-reserve. Our findings highlight the need for culturally appropriate prevention and cessation policies and programs for this at-risk population.Compared with the general population in Canada, Aboriginal youth start smoking earlier¹ and have a higher prevalence of smoking,^1–3 with female Aboriginals at greatest risk.¹ Research has also shown that Aboriginal youth have high rates of binge drinking¹ and are more likely than non-Aboriginal youth to use marijuana.⁴Despite the high prevalence of smoking among Aboriginal youth in Canada, there is a paucity of research related to their patterns of tobacco use, especially among Aboriginals living off-reserve.⁵ Most Aboriginals in Canada live off-reserve,⁶ and those 15 years of age and older are more likely than non-Aboriginals to have chronic health conditions, to drink heavily and to smoke.⁷ Given that the Canadian Tobacco Control Strategy emphasizes targeting youth, young adults, First Nations, Inuit and other Aboriginal groups,⁸ a better understanding of tobacco use among Aboriginal youth living off-reserve is required.We conducted this study to examine patterns of tobacco use, exposure to second-hand smoke and the prevalence of alcohol and other drug use among Aboriginal youth living off-reserve. We compared these data with those for non-Aboriginal youth using nationally representative data from the 2008/09 Youth Smoking Survey.     

我国森林资源生态产品价值实现的基本逻辑、核心机制与模式

基于森林资源生态产品价值实现的研究进程和实践经验,解析森林资源生态产品价值实现的理论逻辑、制度逻辑、技术逻辑,设计以政府主导的森林资源资产化、市场主导的森林资产资本化机制和政府与市场交叉的价值反馈机制,衔接关键要素的森林资源生态产品价值实现核心机制。从实践案例提炼出我国森林资源生态产品价值实现的典型--生态产业化经营模式、绿色金融模式、生态指标交易模式和林下经济模式,其中生态产业化经营模式包括森林资源流转、林业产业多元化发展和生态产业化;绿色金融模式包括生态运营中心模式和股权合作型生态修复;生态指标交易模式主要是森林碳汇交易;林下经济模式的核心做法是林业立体复合生产经营。最后聚焦森林资源生态产品价值实现的三大关键环节:"资源变资产"资产变资本"资本变资金",提出建立森林生态运营中心、采取金融资本化运营和实施森林资源生态产品分类经营的政策建议。     

The Influence of Parenting Change on Pediatric Weight Control

Objective: Parenting style was examined as a predictor of weight loss maintenance in behavioral family‐based pediatric obesity treatment. Research Methods and Procedures: Fifty obese children who participated in a behavioral family‐based pediatric obesity treatment were studied. Hierarchical regression tested the incremental effect of baseline parenting and parenting during treatment on children's percentage overweight change over 12 months, beyond demographics and adherence to targeted behaviors. Results: Children's percentage overweight significantly decreased at 6 (?16.3) and 12 (?11.1) months. Adherence to program goals significantly increased variance accounted for in the regression model by 10.8%, whereas adding baseline father acceptance and change in father acceptance accounted for another 20.5%. The overall model accounted for 40.6% of the variance in pediatric weight control. ANOVA showed significantly greater percentage overweight decrease from baseline for youth with fathers who increased their acceptance vs. those who decreased acceptance at 6 (?19.8 vs. ?14.6) and 12 (?17.4 vs. ?8.1) months. Discussion: Youth who perceive an increase in father acceptance after treatment had better changes in percentage overweight over 12 months than youth with lower ratings of father acceptance. Future directions include examining how other parenting dimensions impact pediatric obesity treatment outcome and how parental acceptance can be enhanced to improve child weight control.     

Patterns of sex ratio, virginity and developmental mortality in gregarious parasitoids

Theory considering sex ratio optima under ‘strict local mate competition with offspring groups produced by a single foundress’ makes a suite of predictions, one of which is a mean female bias. Treating individual offspring as discrete units, theory further predicts sex ratios to have low variance (precise sex ratio) and to equal the reciprocal of clutch size (one male per clutch). The maternal decision may be complicated by imperfect control of sex allocation, limited insemination capacity of sons and offspring developmental mortality: each can lead to virgin daughters (with zero fitness) and consequently select for less biased sex ratios. When clutches are small and/or developmental mortality is common, appreciable proportions of virgins are expected, even when control of sex allocation is perfect and the mating capacity of males is unlimited. This suite of predictions has been only partially tested. We provide further tests by examining sex ratios and developmental mortalities within and across species of locally mating parasitoids. We find a wide range of mean developmental mortalities (6–67%), but mortality distributions are consistendy overdispersed (have greater than binomial variance) and sexually differential mortality appears to be absent. Sex ratios are female biased and have low variance, but are not perfectly precise and variance is increased by mortality within species and (equivocally) across species. Sex ratios less biased than the reciprocal of clutch size are observed; probably due to a maternal response to developmental mortality in one species, and to limited insemination capacity in others. Cross species comparisons indicate that mean proportions of mortality and virginity are positively correlated. Virginity is more prevalent than predicted among species with higher mortalities but not among lower mortality species. Predicted relationships between virginity and clutch size are supported in species with lower mortalities but only partially supported when mortality rates are higher.     

青藏高原地区生态资产核算研究——以西藏自治区山南市为例

生态资产是重要的自然资源资产,也是优质生态产品提供的基础,生态资产的变化趋势可作为衡量生态保护和恢复成效的重要指标。山南市拥有青藏高原地区各种生态资产类型,以山南市为例开展生态资产核算可为青藏高原地区生态资产评估与保护提供参考。以生态资产数量、质量和生态资产指数为主要指标,揭示山南市2000-2015年生态资产的变化趋势及影响因素。结果表明：（1）2015年山南市生态资产以草地和森林为主,分别占生态资产总面积的40.6%和35.8%;但质量不高,优、良等级比例仅占11.8%和12.0%;生态资产综合指数为38.26,草地、森林、灌丛和湿地生态资产指数分别为16.23、14.88、5.37和1.78;（2）2000-2015年,山南市生态资产面积总体变化不大,森林和荒漠生态资产分别增加50.2 km²和43.9 km²,但湿地、农田、草地、灌丛、冰川生态资产面积分别减少97.4、29.8、2.9、2.7、0.3 km²;生态资产质量明显提升,优级和良级生态资产增幅分别为40.5%和108.5%;生态资产指数增加了16.1%;（3）退耕还林还草等生态保护和修复政策、城镇扩张以及气候变化等是山南市生态资产变化的主要因素。     

Identification of quantitative trait loci for shank length and growth at different development stages in chicken

Shank length affects chicken leg health and longer shanks are a source of leg problems in heavy-bodied chickens. Identification of quantitative trait loci (QTL) affecting shank length traits may be of value to genetic improvement of these traits in chickens. A genome scan was conducted on 238 F₂ chickens from a reciprocal cross between the Silky Fowl and the White Plymouth Rock breeds using 125 microsatellite markers to detect static and developmental QTL affecting weekly shank length and growth (from 1 to 12 weeks) in chickens. Static QTL affected shank length from birth to time t , while developmental QTL affected shank growth from time t− 1 to time t . Seven static QTL on six chromosomes (GGA2, GGA3, GGA4, GGA7, GGA9 and GGA23) were detected at ages of 2, 3, 4, 5, 6, 7, 9 and 12 weeks, and six developmental QTL on five chromosomes (GGA1, GGA2, GGA4, GGA5 and GGA23) were detected for five shank growth periods, weeks 2–3, 4–5, 5–6, 10–11 and 11–12. A static QTL and a developmental QTL ( SQSL1 and DQSL2 ) were identified at GGA2 (between ADL0190 and ADL0152 ). SQSL1 explained 2.87–5.30% of the phenotypic variation in shank length from 3 to 7 weeks. DQSL2 explained 2.70% of the phenotypic variance of shank growth between 2 and 3 weeks. Two static and two developmental QTL were involved chromosome 4 and chromosome 23. Two chromosomes (GGA7 and GGA9) had static QTL but no developmental QTL and another two chromosomes (GGA1 and GGA5) had developmental QTL but no static QTL. The results of this study show that shank length and shank growth at different developmental stages involve different QTL.     

Spirituality,Religiosity, and Thriving Among Adolescents: Identification and Confirmation of Factor Structures

Using a data set from Search Institute's research archive, Young Adolescents and Their Parents (YAP), this study ascertained whether religiosity, spirituality, and thriving could be identified and confirmed as separate latent constructs among a randomly selected subsample of 1,000 youth drawn from the larger YAP sample. Factor analytic and structural equation modeling findings provided evidence of the separate, multidimensional presence of the latent constructs (second-order factors) and confirmed the presence of 4 religiosity first-order factors (e.g., role of a faith institution in one's life), 3 spirituality first-order factors (e.g., orientation to help people other than the self), and 9 thriving first-order factors (e.g., future orientation/path to a hopeful future). Limitations of this analyses and directions for future research with this, and related data sets, are discussed.     

Drivers of human development: How relationships and context shape learning and development1

ABSTRACT

This article synthesizes knowledge on the role of relationships and key macroand micro-contexts - poverty, racism, families, communities, schools, and peers - in supporting and/or undermining the healthy development of children and youth, using a relational developmental systems framework. Relationships with parents, siblings, peers, caregivers, and teachers are explored in the context of early care and childhood settings, schools, classrooms, and school-based interventions. Additional contextual factors include; chronic stress, institutionalized racism, stereotype threat, and racial identity. A companion article focuses on how the human brain develops, and the major constructs that define human development, the constructive nature of development, and the opportunities for resilience. Human development occurs through reciprocal coactions between the individual and their contexts and culture, with relationships as the key drivers. Relationships and contexts, along with how children appraise and interpret them, can be risks and assets for healthy learning and development, and their influence can be seen across generations and can produce intra- as well as intergenerational assets and risks. This knowledge about the individual’s responsiveness to context and experience has both positive and negative implications across early childhood, adolescence and into adulthood. Sensitive periods for brain growth and development are considered within the contextual factors that influence development including; parental responsiveness and attunement, intentional skill development, mindfulness, reciprocal interactions, adversity, trauma, and enriching opportunities. The accumulated knowledge on human development and the power of context and culture can inform child-serving systems that support positive adaptations, resilience, learning, health, and well-being.