3,815 research outputs found
Is Achievement Motivation in Basketball Games Affected by Team or Individual Competitive Situations in Elementary Physical Education Classes?
This study examined the relationship between skill, setting and gender. There were three main purposes for conducting this study. The first was to determine whether a child\u27s achievement motivation changes when participating in a team setting compared to an individual setting. The second purpose was to determine and compare any differences between boys\u27 and girls\u27 achievement motivation, in both team and individual settings, and thirdly, to determine and compare any differences between the achievement motivation of high-skilled and low-skilled children, in both team and individual settings. Subjects were administered the Sport Orientation Questionnaire, (Gill and Deeter, 1988), which assesses competitiveness, win-orientation and goal-orientation. Subjects in this study included a total of 117, (70 female, 47 male), 5th and 6th grade students at Jefferson Elementary School in Charleston, Illinois. Participants were categorized into high and low skill ability, (66 high skilled and 51 low skilled participants). Each student completed the Sport Orientation Questionnaire twice, once for team setting and once for individual setting. Students completed the SOQ, referring to feelings about team basketball competition, after four classes involving five-on-five basketball games. Students completed the SOQ a second time after four classes, which were structured on one-on-one competition. In regards to the primary hypothesis, it was determined that a child\u27s achievement motivation does change when participating in a team setting compared to an individual setting. Results using a 3 way MANOVA indicated six significant differences: 1. Boys are more competitive than girls. 2. High-skilled children are more competitive than low-skilled children. 3. High-skilled children prefer to compete in an individual setting while low-skilled children prefer to compete in a team setting. 4. Both genders and skill levels have a stronger desire to win in a team setting compared to an individual setting. 5. Low-skilled children possess a higher motive to accomplish personal goals in a team setting compared to an individual setting. 6. High-skill participants possess a higher motive to achieve personal goals than low-skilled participants
Di- and Trinuclear Mixed-Valence Copper Amidinate Complexes from Reduction of Iodine
Molecular examples of mixed-valence copper complexes through chemical oxidation are rare but invoked in the mechanism of substrate activation, especially oxygen, in copper-containing enzymes. To examine the cooperative chemistry between two metals in close proximity to each other we began studying the reactivity of a dinuclear Cu(I) amidinate complex. The reaction of [(2,6-Me2C6H3N)2C(H)]2Cu2, 1, with I2 in tetrahydrofuran (THF), CH3CN, and toluene affords three new mixed-valence copper complexes [(2,6-Me2C6H3N)2C(H)]2Cu2(Ό2-I3)(THF)2, 2, [(2,6-Me2C6H3N)2C(H)]2Cu2(Ό2-I) (NCMe)2, 3, and [(2,6-Me2C6H3N)2C(H)]3Cu3(Ό3-I)2, 4, respectively. The first two compounds were characterized by UV-vis and electron paramagnetic resonance spectroscopies, and their molecular structure was determined by X-ray crystallography. Both di- and trinuclear mixed-valence intermediates were characterized for the reaction of compound 1 to compound 4, and the molecular structure of 4 was determined by X-ray crystallography. The electronic structure of each of these complexes was also investigated using density functional theory
Novel use Of Hydroxyurea in an African Region with Malaria (NOHARM): a trial for children with sickle cell anemia
Hydroxyurea treatment is recommended for children with sickle cell anemia (SCA) living in high-resource malaria-free regions, but its safety and efficacy in malaria-endemic sub-Saharan Africa, where the greatest sickle-cell burden exists, remain unknown. In vitro studies suggest hydroxyurea could increase malaria severity, and hydroxyurea-associated neutropenia could worsen infections. NOHARM (Novel use Of Hydroxyurea in an African Region with Malaria) was a randomized, double-blinded, placebo-controlled trial conducted in malaria-endemic Uganda, comparing hydroxyurea to placebo at 20 ± 2.5 mg/kg per day for 12 months. The primary outcome was incidence of clinical malaria. Secondary outcomes included SCA-related adverse events (AEs), clinical and laboratory effects, and hematological toxicities. Children received either hydroxyurea (N = 104) or placebo (N = 103). Malaria incidence did not differ between children on hydroxyurea (0.05 episodes per child per year; 95% confidence interval [0.02, 0.13]) vs placebo (0.07 episodes per child per year [0.03, 0.16]); the hydroxyurea/placebo malaria incidence rate ratio was 0.7 ([0.2, 2.7]; P = .61). Time to infection also did not differ significantly between treatment arms. A composite SCA-related clinical outcome (vaso-occlusive painful crisis, dactylitis, acute chest syndrome, splenic sequestration, or blood transfusion) was less frequent with hydroxyurea (45%) than placebo (69%; P = .001). Children receiving hydroxyurea had significantly increased hemoglobin concentration and fetal hemoglobin, with decreased leukocytes and reticulocytes. Serious AEs, sepsis episodes, and dose-limiting toxicities were similar between treatment arms. Three deaths occurred (2 hydroxyurea, 1 placebo, and none from malaria). Hydroxyurea treatment appears safe for children with SCA living in malaria-endemic sub-Saharan Africa, without increased severe malaria, infections, or AEs. Hydroxyurea provides SCA-related laboratory and clinical efficacy, but optimal dosing and monitoring regimens for Africa remain undefined. This trial was registered at www.clinicaltrials.gov as #NCT01976416
Distinguishing among Technicolor/Warped Scenarios in Dileptons
Models of dynamical electroweak symmetry breaking usually include new spin-1
resonances, whose couplings and masses have to satisfy electroweak precision
tests. We propose to use dilepton searches to probe the underlying structure
responsible for satisfying these. Using the invariant mass spectrum and charge
asymmetry, we can determine the number, parity, and isospin of these
resonances. We pick three models of strong/warped symmetry breaking, and show
that each model produces specific features that reflect this underlying
structure of electroweak symmetry breaking and cancellations.Comment: Added missing referenc
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A census of atmospheric variability from seconds to decades
This paper synthesizes and summarizes atmospheric variability on time scales from seconds to decades through a phenomenological census. We focus mainly on unforced variability in the troposphere, stratosphere, and mesosphere. In addition to atmosphere-only modes, our scope also includes coupled modes, in which the atmosphere interacts with the other components of the Earth system, such as the ocean, hydrosphere, and cryosphere. The topics covered include turbulence on time scales of seconds and minutes, gravity waves on time scales of hours, weather systems on time scales of days, atmospheric blocking on time scales of weeks, the MaddenâJulian Oscillation on time scales of months, the Quasi-Biennial Oscillation and El NiñoâSouthern Oscillation on time scales of years, and the North Atlantic, Arctic, Antarctic, Pacific Decadal, and Atlantic Multidecadal Oscillations on time scales of decades. The paper serves as an introduction to a special collection of Geophysical Research Letters on atmospheric variability. We hope that both this paper and the collection will serve as a useful resource for the atmospheric science community and will act as inspiration for setting future research directions
The transcriptional repressor protein NsrR senses nitric oxide directly via a [2Fe-2S] cluster
The regulatory protein NsrR, a member of the Rrf2 family of transcription repressors, is specifically dedicated to sensing nitric oxide (NO) in a variety of pathogenic and non-pathogenic bacteria. It has been proposed that NO directly modulates NsrR activity by interacting with a predicted [Fe-S] cluster in the NsrR protein, but no experimental evidence has been published to support this hypothesis. Here we report the purification of NsrR from the obligate aerobe Streptomyces coelicolor. We demonstrate using UV-visible, near UV CD and EPR spectroscopy that the protein contains an NO-sensitive [2Fe-2S] cluster when purified from E. coli. Upon exposure of NsrR to NO, the cluster is nitrosylated, which results in the loss of DNA binding activity as detected by bandshift assays. Removal of the [2Fe-2S] cluster to generate apo-NsrR also resulted in loss of DNA binding activity. This is the first demonstration that NsrR contains an NO-sensitive [2Fe-2S] cluster that is required for DNA binding activity
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School-level factors associated with the sustainment of weekly physical activity scheduled in Australian elementary schools: an observational study
Background
We aimed to: (1) identify school-level factors associated with the sustainment of weekly physical activity (PA) scheduled in elementary schools following withdrawal of effective implementation support; and (2) determine teacherâs perceived usefulness of suggested strategies for sustaining the scheduling of weekly PA.
Methods
A secondary exploratory analysis was employed of data from the intervention arm (nâ=â31 schools) of a randomised controlled trial. Self-report survey data from 134 classroom teachers in New South Wales, Australia, collected following withdrawal of initial implementation support (follow-up T1) and six-months following completion of support (follow-up T2) were used. The outcomes of sustainment of weekly overall PA and energisers (short classroom PA breaks) scheduled were measured via teachersâ completion of a daily activity logbook, with results presented as the difference in mean minutes of PA and energisers scheduled at T1 and T2. An adapted version of the Program Sustainability Assessment Tool (PSAT) was used to measure capacity for program sustainability across seven key domains at follow-up T2. Linear mixed regressions were conducted to evaluate associations between school-level sociodemographic characteristics (e.g., school size, remoteness, and type), teacher-reported school factors (i.e., seven adapted PSAT domains) and the sustainment of PA and energisers scheduled across the school week. Perceived usefulness of 14 proposed sustainability strategies was measured via the teacher survey at follow-up T2 and reported descriptively.
Results
No school-level factor was statistically associated with the sustainment of overall weekly PA or energisers scheduled. Teacher-reported factors in two PSAT domains â âstrategic planningâ and âprogram evaluationâ were statistically negatively associated with the sustainment of weekly energisers scheduled (â 6.74, 95% CI: â 13.02; â 0.47, pâ=â0.036 andââ 6.65, 95% CI: â 12.17; â 1.12, pâ=â0.019 respectively). The proposed support sustainability strategy â âprovision of PA equipment packs that enable energisers or integrated lessonsâ was perceived useful by the most teachers (85%).
Conclusions
Further research is required to explore additional contextual-specific, and end-user appropriate factors associated with schoolsâ sustainment of weekly PA scheduled. This will help accurately inform the development of strategies to address these determinants and support the sustainment and long-term benefits of school-based health interventions more broadly
Fasting Indicators of Insulin Sensitivity: Effects of Ethnicity and Pubertal Status
OBJECTIVEâTo examine the relationship of fasting indicators of insulin sensitivity with a more invasive measure of insulin sensitivity (frequently sampled intravenous glucose tolerance test [FSIVGTT]) and the effect of Tanner stage and ethnicity on that relationship. RESEARCHDESIGNANDMETHODSâData were analyzed from 149 overweight girls (97 Hispanic and 52 African American) who were either in the early stages of maturation defined by Tanner stages 1 or 2 (52Hispanic and 18 African American) or in the later stages of maturation defined by Tanner stages 4 and 5 (45 Hispanic and 34 African American). Fasting indicators of insulin sensitivity (IS) included fasting insulin and glucose and the homeostasis model assess-ment of insulin resistance (HOMA-IR). IS was derived from an FSIVGTTwithminimalmodeling. RESULTSâIn Tanner stages 1 and 2, all fasting indicators were significantly associatedwith IS
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