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Two second-order meta-analyses synthesized approximately 100 years of research on the effects of ability grouping and acceleration on K-12 students' academic achievement. Outcomes of 13 ability grouping meta-analyses showed that students benefitedfrom within-class grouping (0.19≤g≤0.30), cross-grade subject grouping (g = 0.26), and special grouping for the gifted (g = 0.3 7), but did not benefitfrom between-class grouping (0.04≤g≤0.06); the effects did not vary for high-, medium-, and low-ability students. Three acceleration meta-analyses showed that accelerated students significantly outperformed their nonaccelerated same-age peers (g = 0.70) but did not differ significantly from nonaccelerated older peers (g = 0.09). Three other meta-analyses that aggregated outcomes across specific forms of acceleration found that acceleration appeared to have a positive, moderate, and statistically significant impact on students' academic achievement (g = 0.42).

The Van Allen radiation belts contain ultrarelativistic electrons trapped in Earth's magnetic field. Since their discovery in 1958, a fundamental unanswered question has been how electrons can be accelerated to such high energies. Two classes of processes have been proposed: transport and acceleration of electrons from a source population located outside the radiation belts (radial acceleration) or acceleration of lower-energy electrons to relativistic energies in situ in the heart of the radiation belts (local acceleration). We report measurements from NASA's Van Allen Radiation Belt Storm Probes that clearly distinguish between the two types of acceleration. The observed radial profiles of phase space density are characteristic of local acceleration in the heart of the radiation belts and are inconsistent with a predominantly radial acceleration process.

Humans are undoubtedly altering many geological processes on Earth—and have been for some time. But what is the stratigraphic evidence for officially distinguishing this new human-dominated time period, termed the “Anthropocene,” from the preceding Holocene epoch? Waters et al. review climatic, biological, and geochemical signatures of human activity in sediments and ice cores. Combined with deposits of new materials and radionuclides, as well as human-caused modification of sedimentary processes, the Anthropocene stands alone stratigraphically as a new epoch beginning sometime in the mid–20th century. Science , this issue p. 10.1126/science.aad2622 Human activity is leaving a pervasive and persistent signature on Earth. Vigorous debate continues about whether this warrants recognition as a new geologic time unit known as the Anthropocene. We review anthropogenic markers of functional changes in the Earth system through the stratigraphic record. The appearance of manufactured materials in sediments, including aluminum, plastics, and concrete, coincides with global spikes in fallout radionuclides and particulates from fossil fuel combustion. Carbon, nitrogen, and phosphorus cycles have been substantially modified over the past century. Rates of sea-level rise and the extent of human perturbation of the climate system exceed Late Holocene changes. Biotic changes include species invasions worldwide and accelerating rates of extinction. These combined signals render the Anthropocene stratigraphically distinct from the Holocene and earlier epochs.

With an estimated 3.8 million sport- and recreation-related concussions occurring annually, targeted prevention and diagnostic methods are needed. Biomechanical analysis of head impacts may provide quantitative information that can inform both prevention and diagnostic strategies. To assess available head-impact devices and their clinical utility. We performed a systematic search of the electronic database PubMed for peer-reviewed publications, using the following phrases: accelerometer and concussion, head impact telemetry, head impacts and concussion and sensor, head impacts and sensor, impact sensor and concussion, linear acceleration and concussion, rotational acceleration and concussion, and xpatch concussion. In addition to the literature review, a Google search for head impact monitor and concussion monitor yielded 15 more devices. Included studies were performed in vivo, used commercially available devices, and focused on sport-related concussion. One author reviewed the title and abstract of each study for inclusion and exclusion criteria and then reviewed each full-text article to confirm inclusion criteria. Controversial articles were reviewed by all authors to reach consensus. In total, 61 peer-reviewed articles involving 4 head-impact devices were included. Participants in boxing, football, ice hockey, soccer, or snow sports ranged in age from 6 to 24 years; 18% (n = 11) of the studies included female athletes. The Head Impact Telemetry System was the most widely used device (n = 53). Fourteen additional commercially available devices were presented. Measurements collected by impact monitors provided real-time data to estimate player exposure but did not have the requisite sensitivity to concussion. Proper interpretation of previously reported head-impact kinematics across age, sport, and position may inform future research and enable staff clinicians working on the sidelines to monitor athletes. However, head-impact-monitoring systems have limited clinical utility due to error rates, designs, and low specificity in predicting concussive injury.

COVID-19 confronts the education system with a new and massive crisis. What should a “new normal” look like for future generations? How can countries use the innovativeness of the recovery period to “build back better”? This Viewpoint highlights the UNESCO-led Global Coalition for Education initiative, which is seeking solutions to support learners and teachers, as well as governments throughout the recovery process, with a principal focus on inclusion, equity, and gender equality. The Viewpoint also argues that the current crisis is an opportunity for stronger international collaboration, which might provide a better focus and deliver solutions, including digital tools. Resilience and adaptability will be crucial for the next generations to navigate through the present—and any future—pandemic.

This article documents the patterns of White-Black and White-Hispanic enrollment gaps in Advanced Placement (AP) and Dual Enrollment (DE) programs across thousands of school districts in the United States by merging several data sources. We show that the vast majority of districts have racial enrollment gaps in both programs, with wider gaps in AP than DE. Results from fractional regression models indicate that geographic variations in these gaps can be by both local and state factors. We also find that district-level resources and state policies that provide greater access to AP and DE are also associated with wider racial enrollment gaps, implying that greater resources may engender racial disparity without adequate efforts to provide equitable access and support for minority students.

Heading, an integral component of soccer, exposes athletes to a large number of head impacts over a career. The literature has begun to indicate that cumulative exposure may lead to long-term functional and psychological deficits. Quantifying an athlete's exposure over a season is a first step in understanding cumulative exposure.   To measure the frequency and magnitude of direct head impacts in collegiate women's soccer players across impact type, player position, and game or practice scenario.   Cross-sectional study.   National Collegiate Athletic Association Division I institution.   Twenty-three collegiate women's soccer athletes.   Athletes wore Smart Impact Monitor accelerometers during all games and practices. Impacts were classified during visual, on-field monitoring of athletic events. All direct head impacts that exceeded the 10 g threshold were included in the final data analysis. The dependent variable was linear acceleration, and the fixed effects were (1) type of impact: clear, pass, shot, unintentional deflection, or head-to-head contact; (2) field position: goalkeeper, defense, forward, or midfielder; (3) playing scenario: game or practice.   Shots (32.94 g ± 12.91 g, n = 38; P = .02) and clears (31.09 g ± 13.43 g, n = 101; P = .008) resulted in higher mean linear accelerations than passes (26.11 g ± 15.48 g, n = 451). Head-to-head impacts (51.26 g ± 36.61 g, n = 13; P < .001) and unintentional deflections (37.40 g ± 34.41 g, n = 24; P = .002) resulted in higher mean linear accelerations than purposeful headers (ie, shots, clears, and passes). No differences were seen in linear acceleration across player position or playing scenario.   Nonheader impacts, including head-to-head impacts and unintentional deflections, resulted in higher mean linear accelerations than purposeful headers, including shots, clears, and passes, but occurred infrequently on the field. Therefore, these unanticipated impacts may not add substantially to an athlete's cumulative exposure, which is a function of both frequency and magnitude of impact.

Research on sexual assault prevention programs implemented with young people has largely failed to examine program effects between age groups. This systematic review and meta-analysis synthesizes data from 15 high quality studies (N= 6104) examining the effects of sexual assault prevention bystander programs on bystander efficacy, intentions, and intervention across the college years. Findings indicate bystander programs have a significant, desirable effect on all three outcomes. Effects on bystander intentions were significantly stronger among students in their first two years compared to those in their later years of college. There was no evidence of a significant difference in effects on bystander efficacy or intervention between these two groups. Implications and directions for future research are discussed.

The preparation of future scientists, the technical workforce, and informed citizens will require continued transformation to the ways we approach STEM teaching and learning. Undergraduate STEM education is rapidly emerging as a focus of faculty scholarship, but new models for reform need to be developed and tested to accelerate changes in teaching practices. This paper describes a flexible, participant-driven, multi-phase, collaborative approach to developing open educational resources (OERs) that leverages linked communities of practice (CoPs). Equally valuable, our framework for development, adaptation, dissemination, and validation of OERs provides a platform for faculty professional development and sustained support through cooperative mentoring. The three linked CoPs in the framework include incubators for the creation of initial OERs, Faculty Mentoring Networks (FMNs) for the implementation and adaptation of OERs for classroom use, and Education Research Communities to assess the effectiveness of the OERs. The CoPs create numerous benefits for participating faculty, including the ability to collaborate in the Scholarship of Teaching and Learning (SoTL) through scholarly publication of OERs and their assessment; ongoing mentorship in implementation of OERs in the classroom; and development of educational leadership skills and experience. Thus, the three CoPs synergize with one another to build and sustain capacity through providing vetted, up-to-date educational resources, as well as ongoing training and support for faculty. While we developed this approach for the rapidly changing field of bioinformatics, the linked CoP framework will have utility for STEM education reform more broadly and disciplines beyond STEM.

Since 2004, many researchers have considered that grade skipping has a positive impact on academic achievement and is not detrimental to psychosocial development. However, some recent works have called this evidence into question. Therefore, this literature review aims to verify the consistency and robustness of historical and recent results. This review concludes that: (a) on a global level, recent results are more robust (confounding factors are better controlled) and confirm previous results, but many other controls of confounding factors would need to be made; and (b) professionals may continue to recommend grade skipping, but they must remain cautious. Finally, it is still premature to argue that grade skipping has a definite positive impact, even if the results are encouraging and may at least invite teachers to consider grade skipping as a possible solution.