Yo-Yo IR2 testing of elite and sub-elite soccer players: Performance, heart rate response and correlations to other interval tests

Abstract We examined performance, heart rate response and construct validity of the Yo-Yo IR2 test by testing 111 elite and 92 sub-elite soccer players from Norway and Denmark. VO(2)max, Yo-Yo IR1 and repeated sprint tests (RSA) (n?=?51) and match-analyses (n?=?39) were also performed. Yo-Yo IR2 and Yo-Yo IR1 performance was 41 and 25% better (P??0.05). For top-teams, Yo-Yo IR2 performance (28%) and sprinting distance (25%) during match were greater (P?相似文献   

Broadband for public libraries: Importance,issues, and research needs

U.S. public libraries provide free public internet services to the communities that they serve, but require robust, high-speed broadband internet connections to continue meeting public demands. The 2008–2009 Public Library Funding & Technology Access Study (PLFTAS) illustrates challenges that public libraries encounter in achieving broadband connectivity and equipment upgrades, and maintaining acceptable levels of services as they meet continually increasing internet-enabled service demands. This article: 1) analyzes the ability of public libraries to serve as a community-based public internet access point in the context of limited funding and access to telecommunications services and equipment; 2) discusses key policy issues that affect the provision of public library internet-enabled services through broadband; 3) provides recommendations for policy makers to include libraries as part of a larger national-level telecommunications policy; and 4) identifies a number of topics and issues that need further investigation and research in this shifting policy environment.     

Inhibition of exploratory behavior in the rat by handling

The effect of tail-handling on exploratory behavior of the rat, measured as step-through latency in a well-lighted, two-box apparatus, was investigated. Male adult Wistar rats, aged 60 days, were employed in all three experiments. Experiment 1, in which the subjects were handled at different times after entering the goal chamber (0, 10, 30, 60, 300, and 600 sec), showed that immediate handling, relative to detention in the goal chamber (delay of handling) had an inhibitory effect on exploration. Experiment 2 showed that groups handled immediately after entering the goal chamber but then detained there for different durations all showed the same progressive inhibition of exploration. Experiment 3 showed that the inhibition of exploration (very long step-through latencies) due to tail-handling immediately after entering the goal chamber could be significantly decreased by further trials in which handling was delayed for a sufficient duration (30 sec or more). Handling is discussed as a stimulus that is aversive enough to elicit conditioned passive-avoidance responses (inhibition of exploratory behavior), although it is subject to rapid extinction.     

High-throughput size-based rare cell enrichment using microscale vortices

Cell isolation in designated regions or from heterogeneous samples is often required for many microfluidic cell-based assays. However, current techniques have either limited throughput or are incapable of viable off-chip collection. We present an innovative approach, allowing high-throughput and label-free cell isolation and enrichment from heterogeneous solution using cell size as a biomarker. The approach utilizes the irreversible migration of particles into microscale vortices, developed in parallel expansion-contraction trapping reservoirs, as the cell isolation mechanism. We empirically determined the critical particle∕cell diameter D(crt) and the operational flow rate above which trapping of cells∕particles in microvortices is initiated. Using this approach we successfully separated larger cancer cells spiked in blood from the smaller blood cells with processing rates as high as 7.5×10(6) cells∕s. Viable long-term culture was established using cells collected off-chip, suggesting that the proposed technique would be useful for clinical and research applications in which in vitro culture is often desired. The presented technology improves on current technology by enriching cells based on size without clogging mechanical filters, employing only a simple single-layered microfluidic device and processing cell solutions at the ml∕min scale.     

‘Slow Science’: Building scientific concepts in physics in high school

In this study, a progressive-learning approach to physics, based on knowledge-building pedagogy, was compared to a content-centered approach in which explanations, experiments, and discussions are centered on the transmission of knowledge. Forty-six students attending the first year of high school participated in this study over a whole school year. Students’ knowledge and mastery of physics concepts were assessed through questionnaires containing both open-ended and multiple-choice questions. Overall, the ‘progressive-learning' group outperformed the content-centered group. Results are discussed in relation to the theoretical background and the experimental teacher's diary of classroom activities. The main conclusion achieved by this study is that the teaching of physics should be slow, cyclic, and developmentally appropriate for the context.     

Effectiveness of specific factors in community-based intervention for child-witnesses of interparental violence: A randomized trial

A community-based intervention with specific factors for children and parents exposed to interparental violence (IPV) was compared with a control intervention based on non-specific factors. We hypothesized that participation in an intervention with specific factors, focused on IPV, parenting and coping, would be associated with better recovery. IPV exposed children and parents were group randomized over a specific factors- and control intervention. Baseline, posttest and follow-up measurements of 155 parents and children (aged 6–12 years, 55.5% boys) were fitted in a multilevel model. Outcomes were parent and teacher reported children's internalizing and externalizing problems (CBCL, TRF), child self-reported depressive symptoms (CDI) and parent and child reported children's post-traumatic stress symptoms (TSCYC, TSCC). Based on intention-to-treat and completer analyses, children in the specific factors intervention did not show better recovery than children in the control intervention. Children in both interventions decreased significantly in parent-reported children's internalizing and externalizing problems and post-traumatic stress symptoms. Children reported a decrease in their mean level of depressive and post-traumatic stress symptoms. Teachers reported a decrease in internalizing problems, but not in externalizing problems. No association between time since exposure and level and course of symptoms was found. Treatment differentiation was assessed and both programs were significantly different on hypothesized effective factors. Higher treatment adherence in both programs did not result in a larger difference in recovery. IPV exposed children improve over the course and after participating in a community-based child- and parent program, but specific factors in intervention may not carry additional benefits when implemented in community settings.     

BURNOUT IN SPECIAL NEEDS TEACHERS AT KINDERGARTEN AND PRIMARY SCHOOL: INVESTIGATING THE ROLE OF PERSONAL RESOURCES AND WORK WELLBEING

The purpose of the current study was to examine, within an integrative predictive model, the relative contributions of sociodemographic variables, personal resources, and work wellbeing to teacher burnout. The research was conducted with special education teachers at Italian preschools—a context in which few previous studies have been carried out—and primary schools. A cross‐sectional survey‐based study with a sample of 194 kindergarten and primary school teachers was conducted. The results indicated that teachers’ happiness at school and job satisfaction incrementally predicted variance in personal, work‐related, and student‐related burnout, even after controlling for the effects of sociodemographic factors and personal resources. Furthermore, the final integrative predictive model was similar for both kindergarten and primary teachers.