Identifying and predicting problem behavior trajectories among pre-school children investigated for child abuse and neglect

Objective

Young children involved with child welfare services are at high risk for behavior problems. This study aims to identify externalizing behavior paths that preschoolers in this high-risk population follow over a 6 year period, and the predictors of membership in normative and problematic pathways.

Methods

Using data from the National Study of Child and Adolescent Well-being (NSCAW), the sample included 246 4-year-olds who remained home after investigation. Latent class growth analysis (LCGA) was used to estimate the number, size, and shape of subgroups of preschoolers following distinct behavioral pathways. Early predictors of membership in the resulting groups were then examined.

Results

Four groups of preschool children following distinct behavior trajectories over 6 years were identified. Weighted results show that more than half (61%) of the children followed a low/normal problem behavior trajectory while just over one tenth (12%) were on a persistent high trajectory, remaining in the clinical range throughout the study. Improving (23%) and worsening (4%) problem behavior groups were also identified. Internalizing problems, attention problems, child ethnicity, and maltreatment type reported at age 4 predicted membership in the trajectory groups.

Conclusions

Internalizing behavior problems and maltreatment type may distinguish preschool children who are more likely to experience worsening or persistent problematic externalizing behaviors from those likely to follow a normal behavior trajectory.

Practice implications

Identifying early indicators of externalizing behavior problems and addressing them with evidence-based interventions to reduce negative behaviors may avert long-term negative outcomes.     

Microfluidic wet spinning of chitosan-alginate microfibers and encapsulation of HepG2 cells in fibers

The successful encapsulation of human hepatocellular carcinoma (HepG2) cells would greatly assist a broad range of applications in tissue engineering. Due to the harsh conditions during standard chitosan fiber fabrication processes, encapsulation of HepG2 cells in chitosan fibers has been challenging. Here, we describe the successful wet-spinning of chitosan-alginate fibers using a coaxial flow microfluidic chip. We determined the optimal mixing conditions for generating chitosan-alginate fibers, including a 1:5 ratio of 2% (w∕w) water-soluble chitosan (WSC) solution to 2% (w∕w) alginate solution. Ratio including higher than 2% (w∕w) WSC solution increased aggregation throughout the mixture. By suspending cells in the WSC-alginate solution, we successfully fabricated HepG2 cell-laden fibers. The encapsulated HepG2 cells in the chitosan-alginate fibers were more viable than cells encapsulated in pure alginate fibers, suggesting that cross-linked chitosan provides a better environment for HepG2 cells than alginate alone. In addition, we found that the adhesion of HepG2 cells on the chitosan-alginate fiber is much better than that on the alginate fibers.     

Stem cells in microfluidics

Microfluidic techniques have been recently developed for cell-based assays. In microfluidic systems, the objective is for these microenvironments to mimic in vivo surroundings. With advantageous characteristics such as optical transparency and the capability for automating protocols, different types of cells can be cultured, screened, and monitored in real time to systematically investigate their morphology and functions under well-controlled microenvironments in response to various stimuli. Recently, the study of stem cells using microfluidic platforms has attracted considerable interest. Even though stem cells have been studied extensively using bench-top systems, an understanding of their behavior in in vivo-like microenvironments which stimulate cell proliferation and differentiation is still lacking. In this paper, recent cell studies using microfluidic systems are first introduced. The various miniature systems for cell culture, sorting and isolation, and stimulation are then systematically reviewed. The main focus of this review is on papers published in recent years studying stem cells by using microfluidic technology. This review aims to provide experts in microfluidics an overview of various microfluidic systems for stem cell research.     

Energy Performance and Condensation Risk of DCDV System in Subtropical Hong Kong简

The combined use of dry cooling （DC） system and dedicated ventilation （DV） system to decouple cool-ing and dehumidification process for energy efficiency was proposed for subtropical climates like Hong Kong. In this study, the energy performance and condensation risk of the use of DCDV system were examined by analyzing its ap-plication in a typical office building in Hong Kong. Through hour-by-hour simulation using actual equipment per-formance data and realistic building and system characteristics, it was found that with the use of DCDV system, the annual energy consumption could be reduced by 54%in comparison with the conventional system （constant air vol-ume with reheat system）. In respect of condensation risk, it was found that the annual frequency of occurrence of con-densation on DC coil was 35 h. Additional simulations were conducted to examine the influence of different parame-ters on the condensation risk of DCDV system. Measures to ensure condensate-free on DC coil were also discussed.     

《终身教育法》修正后韩国终身教育振兴政策的动向及特征

近10年来,从终身教育的立法到各项政策的推广实施,韩国终身教育领域出现了前所未有的变化。2007年修正的韩国《终身教育法》的公布不仅明确了终身教育的范围,而且也使中央与地方的职责与权限更加明确,并通过重组力图建构更加完善且有效率的终身教育行政与财政支援体制。为了振兴终身教育,韩国大力开展了相应的支援计划：终身学习城市支援计划;终身学习账户制度;终身学习中心大学培育计划;终身教育专业人员的培养及其能力提升计划等。呈现的特点：一是国家相关政策的制定与引导是推进终身教育的根本动力．足够的经费和人力资源支撑是必要条件。二是注重整合各类教育资源,特别是在建立多样的终身教育机构和设施等平台的同时,也注重发挥学校教育的作用。三是实施面向全员并开展全程的终身教育,特别注重增加弱势群体的教育机会。这次修正不仅促进了各自治团体终身教育基础设施的建设,提升了社区网络的发展水平,而且还建立了将学习成果运用于地方的循环体系,促进了国民对终身教育的理解及参与,推动了韩国社会的协调发展。     

Identifying the Content,Lesson Structure,and Data Use Within Pre-collegiate Data Science Curricula

Journal of Science Education and Technology - As data become more available and integrated into daily life, there has been growing interest in developing data science curricula for youth in...     

Revisioning Fairness as Social Justice in Early Childhood Education

Early Childhood Education Journal - Young children’s ideas of fairness have been studied in a range of laboratory settings with findings that children see fairness as equal distribution of...     

A methodological framework for instructional design model development: Critical dimensions and synthesized procedures

Instructional design (ID) models have been developed to promote understandings of ID reality and guide ID performance. As the number and diversity of ID practices grows, implicit doubts regarding the reliability, validity, and usefulness of ID models suggest the need for methodological guidance that would help to generate ID models that are relevant and appropriate to the ever-changing design challenges in our world. Because the construction of an ID model involves an intricate externalization of unique sets of design experiences as well as a logical synthesis of relevant research, the purpose of this study was to formulate a methodological framework for ID model development. Through the analysis of 20 selected studies, four critical dimensions and ten synthesized procedures for constructing ID models were formulated. The resulting framework is intended to provide a useful theoretical and practical contribution to the field of ID.     

IMPACT OF EXPLICIT PRESENTATION OF SLOPES IN THREE DIMENSIONS ON STUDENTS’ UNDERSTANDING OF DERIVATIVES IN MULTIVARIABLE CALCULUS

In two dimensions (2D), representations associated with slopes are seen in numerous forms before representations associated with derivatives are presented. These include the slope between two points and the constant slope of a linear function of a single variable. In almost all multivariable calculus textbooks, however, the first discussion of slopes in three dimensions (3D) is seen with the introduction of partial derivatives. The nature of the discussions indicates that authors seem to assume that students are able to naturally extend the concept of a 2D slope to 3D and correspondingly it is not necessary to explicitly present slopes in 3D. This article presents results comparing students that do not explicitly discuss slopes in 3D with students that explicitly discuss slopes in 3D as a precursor to discussing derivatives in 3D. The results indicate that students may, in fact, have significant difficulty extending the concept of a 2D slope to a 3D slope. And that the explicit presentation of slopes in 3D as a precursor to the presentation of derivatives in 3D may significantly improve student comprehension of topics of differentiation in multivariable calculus.