Global estimates of the implications of COVID-19-related preprimary school closures for children’s instructional access,development, learning,and economic wellbeing

Observational data collected prior to the pandemic (between 2004 and 2019) were used to simulate the potential consequences of early childhood care and education (ECCE) service closures on the estimated 167 million preprimary-age children in 196 countries who lost ECCE access between March 2020 and February 2021. COVID-19-related ECCE disruptions were estimated to result in 19.01 billion person-days of ECCE instruction lost, 10.75 million additional children falling “off track” in their early development, 14.18 million grades of learning lost by adolescence, and a present discounted value of USD 308.02 billion of earnings lost in adulthood. Further burdens associated with ongoing closures were also forecasted. Projected developmental and learning losses were concentrated in low- and lower middle-income countries, likely exacerbating long-standing global inequities.     

The Attrition of Change: A Study of Change and Continuity

In this article models and theories on effective schooling are reviewed. Modelling is based on the various disciplinary oriented approaches to educational effectiveness. As such production functions, instructional effectiveness models and integrated, multi‐level educational effectiveness models are discussed. Various conceptual and formal representations of facilitation across levels are seen as the most interesting area for further model‐driven research. In the second part of the article four organization theories are discussed, all of which are seen as specific interpretations of the rationality paradigm: rational control theory and bureaucratic structuring; contingency theory; public choice theory; and retroactive planning. A fifth theoretical perspective, chaos theory, as applied to organizational functioning, looks more like a complete anti‐thesis of rationality, but can nevertheless be related to the emergence of ordered patterns and to organizational survival. Core mechanisms or theory‐embedded principles that follow from these theories are, respectively: proactive structuring; fit; market mechanisms; the cybernetic principle; and self‐organization. Further analysis of these principles leads to the conclusion that the cybernetic principle of evaluation feedback and reinforcement is the most interesting one, both from a theoretical and practice‐oriented perspective. Throughout the article hints and suggestions are provided for future, more theory and model‐driven educational effectiveness research.     

Potentiation of sprint cycling performance: the effects of a high-inertia ergometer warm-up

ABSTRACT

Participant and protocol factors affect post-activation potentiation response. Performance enhancement is more consistent in highly-trained participants following multiple sets of a biomechanically similar conditioning activity. Providing optimal conditions, 6 international-level sprint cyclists executed multiple sets of short maximal conditioning contractions on a high-inertia ergometer before metered sprint performance. Three trial conditions were completed on separate days after a standardised warm-up: dynamic (DYN: 4 × 4 crank-cycles), isometric (ISO: 4 × 5-sec maximal voluntary contraction (MVC)), and control (CON: rest). Performance was measured from standing start to maximum velocity on an inertial-load ergometer at baseline (Pre), 4 (Post4), 8 (Post8) and 16 (Post16) min post-conditioning. Performance and biomechanical measures were assessed across 4 sprint segments, with magnitude-based inferences used to assess the likelihood that any affect was beneficial. Performance time only improved in DYN Post4, a 3.9% reduction during the first crank cycle (92% likely). On the ascending limb of the power-cadence relationship, peak torque and average power increased by 6.2% (94% likely) and 4.0% (87% likely), respectively. In ISOPost16, optimal cadence increased (82% likely) and average power improved over the descending limb (76% likely). DYN and ISO potentiated extremities of the torque-cadence relationship at distinct recovery times post-conditioning. This study suggests merit in including a high-inertia warm-up for sprint cycling.     

The health information specialist: a new resource for hospital library services and education programs

Growing pressures for more effective education programs at community hospitals demand better and more responsive hospital library resources and services. It is suggested that, with a modest amount of additional training and support, a community hospital librarian can play a key role in (1) improving the effectiveness of the hospital's library services and resources, (2) assisting hospital educators with the task of developing, implementing, and evaluating education programs, and (3) facilitating coordination of health information resources and services with all aspects of hospital education programs. An expanded, more active role, that of the Health Information Specialist, is suggested for hospital librarians. A one-week training program for librarians and special orientation for hospital educators and administrators plus followup field consultation for all three is described and proposed as an implementation strategy to provide the background and impetus needed to help hospital librarians evolve and expand their functional role into that of a Health Information Specialist.     

Performance and physiological effects of different descending strategies for cross-country mountain biking

This study investigated the performance-related feasibility and physiological benefits of purposefully eliminating propulsive work while descending in mountain biking and compared values to those measured during road descending. Participants cycled uphill on a road at race pace before descending over three conditions (off-road pedalling; off-road coasting; road coasting). Relatively low power output during off-road pedalling was associated with a greater oxygen uptake (p?<?.01) when compared with off-road coasting despite no difference in vibration exposure (p?>?.05). Importantly, pedalling did not invoke a performance benefit (p?>?.05) on the descent used in this study. Significantly greater heart rate and oxygen uptake (both p?<?.01) were observed between road and off-road descending, likely caused by the increase in terrain-induced vibrations (p?<?.01) experienced between the bicycle and rider. Results indicate that reducing propulsive work during descending can improve recovery without being disadvantageous to performance. Similarly, the vibrations experienced during road descending are relatively low, and further reduce oxygen cost. In an effort to increase efficiency, it is recommended that mountain bike athletes focus on skills to increase descending speed without the addition of pedalling, and that equipment be used to decrease vibrations nearer to those seen on the road.     

The influence of tyre characteristics on measures of rolling performance during cross-country mountain biking

This investigation sets out to assess the effect of five different models of mountain bike tyre on rolling performance over hard-pack mud. Independent characteristics included total weight, volume, tread surface area and tread depth. One male cyclist performed multiple (30) trials of a deceleration field test to assess reliability. Further tests performed on a separate occasion included multiple (15) trials of the deceleration test and six fixed power output hill climb tests for each tyre. The deceleration test proved to be reliable as a means of assessing rolling performance via differences in initial and final speed (coefficient of variation (CV) = 4.52%). Overall differences between tyre performance for both deceleration test (P = 0.014) and hill climb (P = 0.032) were found, enabling significant (P < 0.0001 and P = 0.049) models to be generated, allowing tyre performance prediction based on tyre characteristics. The ideal tyre for rolling and climbing performance on hard-pack surfaces would be to decrease tyre weight by way of reductions in tread surface area and tread depth while keeping volume high.     

Leg Muscle Metabolism in Trained and Untrained Men

The purpose of this study was to describe substrate changes in blood and muscles during submaximal exercise and to look at the relationship of these changes to some enzyme activities important in lipid and carbohydrate metabolism. A group of six trained and six untrained men were exercised for 1 hour at 50% [Vdot]O₂ max; three from each group cycled and the rest ran on a treadmill. During the exercise, blood-free fatty acid (FFA) levels increased twofold, glycerol by 3.6 times, triglyceride (TG) by 11/100 ml, and glucose by a mean 11 mg/100 ml in the trained men. In the untrained subjects, however, FFA increased 1.8 fold, glycerols 1.6 fold, and TG by a mean 24/100 ml. Glucose fell in every subject by an average 5 mg%. Muscle glycogen depletion averaged 34 mmoles/kg in the untrained and 23 mmoles/kg in the trained group. The activities of succinic acid dehydrogenase (SDH), malic acid dehydrogenase (MDH), and carnitine palmityl transferase (CPT) were greater by 177%, 93%, and 64%, respectively, in the trained group than in the untrained subjects. The results indicated that at the same percent [Vdot]O₂ max, the trained men seemed to “preferentially” use FFA as an energy source, possibly due to a well developed Krebs cycle and increased CPT activities. This preference would tend to inhibit the major rate-limiting enzymes of glycolysis, thus slowing even further the use of carbohydrates as an energy source. The differences in response to exercise were independent of fiber type and indicate that these catabolic responses were primarily due to aerobic training.