Compression garments and cerebral blood flow: Influence on cognitive and exercise performance     

Brittany A. Smale  Joseph M. Northey  Disa J. Smee  Nathan G. Versey 《European Journal of Sport Science》2018,18(3):315-322

This study aimed to describe the effect of compression garments on middle cerebral artery blood flow velocity (MCA_v) in relation to cognitive and exercise performance whilst cycling. In a randomised-controlled-cross-over design, 15 well-trained male cyclists were recruited to participate in three identical trials wearing loose fitting shorts (control), low-grade, or medium-grade compression garments. The protocol involved four 8?min increments of cycling at 30%, 50%, 70%, and 85% maximal power output and a 4?km time-trial. Participants undertook a cognitive Stroop task at baseline and at the midpoint of each increment. MCA_v was monitored with Transcranial Doppler Ultrasonography. Mean arterial pressure (MAP) and partial pressure of end-tidal CO₂ (P_etCO₂) were measured throughout. MCA_v, MAP, P_etCO₂, and reaction time of the complex Stroop task were influenced by exercise intensity, but not compression garments. Compression garments significantly affected cognitive accuracy in the complex Stroop task such that low-grade compression appeared to enhance cognitive accuracy in comparison to the control condition at the highest intensity (p?=?.010). Time-trial performance did not differ between the control (338.0?±?17.3 s), low-grade (338.7?±?18.7 s), or medium-grade (342.2?±?19.3 s) conditions (p?=?.114). Compression garments did not affect MCA_v during exercise or time-trial performance, but compression may be beneficial for improved cognitive accuracy during high-intensity exercise. Further research is required to elucidate the potential impact on cognitive performance.  相似文献   

Three-dimensional anthropometric analysis: Differences between elite Australian rowers and the general population     

Natasha Schranz  Grant Tomkinson  Tim Olds  Nathan Daniell 《Journal of sports sciences》2013,31(5):459-469

Abstract

The aim of this study was to quantify the anthropometric differences between elite senior Australian rowers and the Australian adult population using three-dimensional (3D) whole-body scanning. The dimensions of senior rowers competing at the 2007–2008 Australian Rowing Championships were compared with those of an age-matched sample of Australian adults. Mass, height, and sitting height were measured before the participants underwent a 3D whole-body scan, with lengths, breadths, girths, cross-sectional and surface areas, and volumes extracted from each scan. Differences in means and variability between the two groups were expressed as standardized effect sizes and ratios of coefficients of variation. Heavyweight rowers were generally much larger than the general population in absolute size, with 3D dimensions and height and mass showing the largest effects. In contrast, lightweight rowers were generally similar or smaller in absolute and proportional size. The dimensions of rowers, especially the lightweights, were also generally less variable than those of the general population. The greatest differences between elite rowers and the general population were seen in dimensions that could not be captured without 3D scanning, such as segmental volumes and cross-sectional areas.  相似文献   

Notes: Evaluation of Physical Education in North Carolina High Schools     

Nathan Taylor Dodson 《Research quarterly for exercise and sport》2013,84(2):243-244

Abstract

The purpose of this study was to determine if there were differences in learning to perform a novel motor task between two equated groups: one group was subjected to learning the task immediately following a heavy physical work bout on a bicycle ergometer; the other group was subjected to learning the task with no imposed physical exercise. It was found that the subjects who practiced the stabilometer exercise in a fatigued state performed significantly better than subjects in the control group except for test 4. The experimental group also performed significantly better than the control group during the 5th test which was performed without any fatiguing task. It appears from this study that the fatigue state of the learner had a favorable influence on both performance and learning of certain novel motor skills.  相似文献   

Weaving a New 'Net: A Mesh-Based Solution for Democratizing Networked Communications     

Aram Sinnreich  Nathan Graham  Aaron Trammell 《The Information Society》2013,29(5):336-345

Although the Internet is largely decentralized in its communication and social patterns, its technical and regulatory apparatuses are highly centralized and hierarchical. Consequently, digital communications are vulnerable to a degree of surveillance and censorship that would be unthinkable in traditional social arenas, threatening “Internet freedom” and cyberliberties in both democratic and politically repressed societies. We believe a new architecture is required in order to protect the continuance of civil liberties in networked society. In this article, we propose 10 “social specifications” describing the requirements of such a network, and outline an architecture called MondoNet that meets these specifications using ad hoc, wireless mesh networking technologies. We also address the legal and technical challenges facing the MondoNet project, and anticipate future developments in this field.  相似文献   

The War that Ended Peace: The Road to 1914     

Nathan Crick 《Quarterly Journal of Speech》2016,102(2):221-224

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Structured Play for Preschoolers with Developmental Delays     

Nathan M. Murata  Julienne K. Maeda 《Early Childhood Education Journal》2002,29(4):237-240

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Exploring a Personal Social Knowledge Network (PSKN) to aid the observation of connectivist interaction for high- and low-performing learners in connectivist massive open online courses     

Jinju Duan  Kui Xie  Nathan A. Hawk  Shengquan Yu  Minjuan Wang 《British journal of educational technology : journal of the Council for Educational Technology》2019,50(1):199-217

This study adds a new perspective to the observations about connectivist interaction behavior in cMOOCs by extending the notion of network building from the perspective of individuals. We explore the possibility of building a learning network named Personal Social Knowledge Network (PSKN) to support in the monitoring of learning performance and interaction in cMOOCs. The sample in this study included 284 preservice teachers and their learning lasted approximately 12 weeks. Data were primarily gathered by PSKN graphs. The results revealed a correlation between connectivist interaction measured by the PSKN (including density structure) and learning performance. The results also revealed differences in connectivist interaction behavior and patterns, indicated by PSKN (densities and structures), for high- and low-performing learners in cMOOCs. The high-performing learners show deeper knowledge interaction and social communication in addition to simple knowledge sharing and social communication. Additionally, as time passed and the PSKN of high-performing learners extended further, their interaction behavior became more complex and their role had gradually changed from “learning” to “teaching” as well as from knowledge acceptance to knowledge creation in cMOOCs.  相似文献   

Mobiles for literacy in developing countries: An effectiveness framework     

Daniel A. Wagner  Nathan M. Castillo  Katie M. Murphy  Molly Crofton  Fatima Tuz Zahra 《Prospects》2014,44(1):119-132

In recent years, the advent of low-cost digital and mobile devices has led to a strong expansion of social interventions, including those that try to improve student learning and literacy outcomes. Many of these are focused on improving reading in low-income countries, and particularly among the most disadvantaged. Some of these early efforts have been called successful, but little credible evidence exists for those claims. Drawing on a robust sample of projects in the domain of mobiles for literacy, this article introduces a design solution framework that combines intervention purposes with devices, end users, and local contexts. In combination with a suggested set of purpose-driven methods for monitoring and evaluation, this new framework provides useful parameters for measuring effectiveness in the domain of mobiles for literacy.  相似文献   

Promoting early literacy through the professional development of preschool teachers     

Cristianne Lane  Mary Jo Surges Prokop  Blanche Podhajski  Jane Nathan 《Early Years: An International Journal of Research and Development》2014,34(1):67-80

The purpose of this study was to examine the effect of a professional learning program on the emergent literacy skills of preschool children. Building Blocks for Literacy^® is a program consisting of training supported by mentoring designed to teach early childcare providers how to promote the development of early literacy skills. A previous investigation found positive effects of the program on the pre-literacy skills of children in Vermont. The current study extended their work by replicating the training for Head Start teachers (n?=?27) in another state. Teachers were divided into three groups. One group received the training and live mentoring; a second group received training and distance mentoring; and a third group of teachers served as controls. The results indicate that children (n?=?97) served by teachers who received the training (n?=?18) made higher gains on a measure of early literacy skills than those children (n?=?36) served by control teachers. The gains made by children in the treatment groups were consistent for teachers who received either live or distance mentoring. Implications for practice are discussed.  相似文献   

Humor ability,unwillingness to communicate,loneliness, and perceived stress: Testing a security theory   总被引：1，自引：0，他引：1  

Nathan Miczo 《Communication Studies》2013,64(2):209-226

The purpose of this study was to develop and test a theory of the laughter‐humor link in interpersonal communication. The basic premise of the theory is that a sense of security underlies the ability to encode humor in everyday conversation. It was hypothesized that communication‐related security (i.e., willingness to communicate) predicts humor ability, which in turn negatively predicts loneliness and perceived stress. Undergraduates completed a survey including the following scales: Unwillingness‐ to‐Communicate, Humor Orientation, Coping Humor, revised UCLA Loneliness, and Perceived Stress. Regression analyses confirm that willingness to communicate predicted humor orientation, while humor orientation mediated the relationship between willingness to communicate and coping humor. Humor orientation negatively predicted loneliness and perceived stress, although in both cases willingness to communicate mediated the relationships. The discussion highlights methodological limitations (e.g., use of self‐report) and reiterates the need for interaction‐ and context‐based studies of the laughter‐humor relationship.  相似文献