A Bayesian Method for Evaluating Passing Scores: The PPoP Curve

In this note, we demonstrate an interesting use of the posterior distributions (and corresponding posterior samples of proficiency) that are yielded by fitting a fully Bayesian test scoring model to a complex assessment. Specifically, we examine the efficacy of the test in combination with the specific passing score that was chosen through expert judgment, or, in general, any external a priori criterion. In addition, we study the robustness of the test's efficacy with respect to choice of the passing score.     

The oxygen-conserving potential of the diving response: A kinetic-based analysis

We investigated the oxygen-conserving potential of the human diving response by comparing trained breath-hold divers (BHDs) to non-divers (NDs) during simulated dynamic breath-holding (BH). Changes in haemodynamics [heart rate (HR), stroke volume (SV), cardiac output (CO)] and peripheral muscle oxygenation [oxyhaemoglobin ([HbO₂]), deoxyhaemoglobin ([HHb]), total haemoglobin ([tHb]), tissue saturation index (TSI)] and peripheral oxygen saturation (SpO₂) were continuously recorded during simulated dynamic BH. BHDs showed a breaking point in HR kinetics at mid-BH immediately preceding a more pronounced drop in HR (?0.86 bpm.%^?1) while HR kinetics in NDs steadily decreased throughout BH (?0.47 bpm.%^?1). By contrast, SV remained unchanged during BH in both groups (all P > 0.05). Near-infrared spectroscopy (NIRS) results (mean ± SD) expressed as percentage changes from the initial values showed a lower [HHb] increase for BHDs than for NDs at the cessation of BH (+24.0 ± 10.1 vs. +39.2 ± 9.6%, respectively; P < 0.05). As a result, BHDs showed a [tHb] drop that NDs did not at the end of BH (?7.3 ± 3.2 vs. ?3.0 ± 4.7%, respectively; P < 0.05). The most striking finding of the present study was that BHDs presented an increase in oxygen-conserving efficiency due to substantial shifts in both cardiac and peripheral haemodynamics during simulated BH. In addition, the kinetic-based approach we used provides further credence to the concept of an “oxygen-conserving breaking point” in the human diving response.     

Effects of purposeful soccer heading on circulating small extracellular vesicle concentration and cargo

BackgroundConsidering the potential cumulative effects of repetitive head impact (HI) exposure, we need sensitive biomarkers to track short- and long-term effects. Circulating small extracellular vesicles (sEVs) (<200 nm) traffic biological molecules throughout the body and may have diagnostic value as biomarkers for disease. The purpose of this study was to identify the microRNA (miRNA) profile in circulating sEVs derived from human plasma following repetitive HI exposure.MethodsHealthy adult (aged 18–35 years) soccer players were randomly assigned to one of 3 groups: the HI group performed 10 standing headers, the leg impact group performed 10 soccer ball trapping maneuvers over 10 min, and the control group did not participate in any soccer drills. Plasma was collected before testing and 24 h afterward, and sEVs were isolated and characterized via nanoparticle tracking analysis. Next-generation sequencing was utilized to identify candidate miRNAs isolated from sEVs, and candidate microRNAs were analyzed via quantitative polymerase chain reaction. In silico target prediction was performed using TargetScan (Version 7.0; targetscan.org) and miRWalk (http://mirwalk.umm.uni-heidelberg.de/) programs, and target validation was performed using luciferase reporter vectors with a miR-7844-5p mimic in human embryonic kidney (HEK) 293T/17 cells.ResultsPlasma sEV concentration and size were not affected across time and group following repetitive HI exposure. After 24 h, the HI read count from next-generation sequencing showed a 4-fold or greater increase in miR-92b-5p, miR-423-5p, and miR-24-3p and a 3-fold or greater decrease in miR-7844-5p, miR-144-5p, miR-221-5p, and miR-22-3p. Analysis of quantitative polymerase chain reaction revealed that leg impact did not alter the candidate miRNA levels. To our knowledge, miR-7844-5p is a previously unknown miRNA. We identified 8 miR-7844-5p mRNA targets: protein phosphatase 1 regulatory inhibitor subunit 1B (PPP1R1B), LIM and senescent cell antigen-like domains 1 (LIMS1), autophagy-related 12 (ATG12), microtubule-associated protein 1 light chain 3 beta (MAP1LC3B), integrin subunit alpha-1 (ITGA1), mitogen-activated protein kinase 1 (MAPK1), glycogen synthase kinase 3β (GSK3β), and mitogen-activated protein kinase 8 (MAPK8).ConclusionCollectively, these data indicate repetitive HI exposure alters plasma sEV miRNA content, but not sEV size or number. Furthermore, for the first time we demonstrate that previously unknown miR-7844-5p targets mRNAs known to be involved in mitochondrial apoptosis, autophagy regulation, mood disorders, and neurodegenerative disease.     

Applications of Augmented Reality in Informal Science Learning Sites: a Review

The importance of increasing interest in the STEM disciplines has been noted in a number of recent national reports. While many previous studies have focused on such efforts inside of the formal classroom, comparatively few have looked closely at informal learning environments. We investigate the innovative use of technology in informal learning by reviewing research on the incorporation of augmented reality (AR) at exhibit-based informal science education (ISE) settings in the literature. We report on the common STEM-focused topics that are covered by current AR applications for ISE learning, as well as the different devices used to support these applications. Additionally, we report on the prevalence of positive learning outcomes and engagement factors commonly associated with the use AR applications in informal environments. This review aims to foster continued development and implementation of AR technology in exhibit-based ISE settings by informing the community of recent findings and promoting additional rigorous research for the future.     

Mobiles and Cancer: A Case of Phony Connections?

Students learning statistics want to know how our methods are used in the real world. In response, this article offers a discussion of a relevant and timely medical study reported in recent headlines. Careful consideration of the study raises some ideas to get students engaged with statistics.     

Social Studies Education in the Age of Testing and Accountability

With 3 years and counting since its inception, the scope and impact of No Child Left Behind is now being felt in classrooms across the nation. Although some successes have been identified, concerns about the implementation and expectations of the legislation are emerging. As a result of the legislation's emphasis on the development of standards and assessment systems in reading, mathematics, and science, educators of other core and elective subjects are weighing the impact of being left out of the No Child Left Behind formula of testing and accountability. In an attempt to ascertain the perceptions and sentiments of social studies teachers concerning the impact of No Child Left Behind and the concomitant issue of state-level testing and accountability policy, a tristate study was conducted. The findings of this research indicate that although elementary, middle, and high school social studies educators recognize the negative consequences of being left out of No Child Left Behind, they are not convinced that being included would be better for them, their students, or social studies education in general.