Detracking America's schools: Equity at zero cost?

Schools across the country are ending the practice of grouping students based on ability, in part, because of research indicating that tracking hurts low-ability students without helping students of other ability levels. Using a nationally representative survey conducted by the National Center for Education Statistics, (NCES) we reexamine the impact of tracking on high school student achievement through the estimation of a standard education production function. This approach allows us to control for the possibility that track is correlated with factors such as class size and teacher education. In addition, we address the possibility that there are unobserved student or school characteristics that affect both achievement and track placement. Our results indicate that abolishing tracking in America's schools would have a large positive impact on achievement for students currently in the lower tracks, but that this increase in achievement would come at the expense of students in upper-track classes.     

Motivations for Social Media Use: Associations with Social Media Engagement and Body Satisfaction and Well-Being among Adolescents

Journal of Youth and Adolescence - Adolescents are spending considerable time on social media, yet it is unclear whether motivations for social media use drive different forms of social media...     

Longitudinal Discrepancy in Adolescent Aggressive Behavior Problems: Differences by Reporter and Contextual Factors

Journal of Youth and Adolescence - Little is known about the developmental course of informant discrepancies in adolescent aggressive behavior problems, though whether aggression increases or...     

波兰供热改革及其对北京市的启示

始于20世纪90年代的波兰供热改革和我国北方地区正在进行的供热体制改革具有相似性.首先,所处的经济背景相似.     

高等教育创新的新机遇

人口结构的变化、科学技术的变革以及经济全球化,都对高等教育产生了很大影响,提供了很多新的机遇。这些机遇不仅可以提高我们的效率,同时也可以带来新的创造知识和传播知识的方式方法。     

Parent–Adolescent Conflict across Adolescence: Trajectories of Informant Discrepancies and Associations with Personality Types

Journal of Youth and Adolescence - Parent–adolescent conflict can be intense, yet parents and adolescents do not always agree on the intensity of conflict. Conflict intensity tends to change...     

Patterns of Young Adult Social Roles Transitions Across 24 Months and Subsequent Substance Use and Mental Health

Journal of Youth and Adolescence - Young adults experience social role transitions across multiple life domains, and a deeper understanding of the ways in which these simultaneous transition...     

Volatile Organic Compound Profiling from Postmortem Microbes using Gas Chromatography–Mass Spectrometry

Volatile organic compounds (VOCs) are by-products of cadaveric decomposition and are responsible for the odor associated with decomposing remains. The direct link between VOC production and individual postmortem microbes has not been well characterized experimentally. The purpose of this study was to profile VOCs released from three postmortem bacterial isolates (Bacillus subtilis, Ignatzschineria indica, I. ureiclastica) using solid-phase microextraction arrow (SPME Arrow) and gas chromatography–mass spectrometry (GC-MS). Species were inoculated in headspace vials on Standard Nutrient Agar and monitored over 5 days at 24°C. Each species exhibited a different VOC profile that included common decomposition VOCs. VOCs exhibited upward or downward temporal trends over time. Ignatzschineria indica produced a large amount of dimethyldisulfide. Other compounds of interest included alcohols, aldehydes, aromatics, and ketones. This provides foundational data to link decomposition odor with specific postmortem microbes to improve understanding of underlying mechanisms for decomposition VOC production.