693 research outputs found

    Gender, perceived competence and the enjoyment of physical education in children: a longitudinal examination

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    <p>Abstract</p> <p>Background</p> <p>The current study examined associations between gender, perceived athletic competence, and enjoyment of physical education (PE) class over time in a cohort of children enrolled in grade four (ages 9 or 10) at baseline (n = 2262).</p> <p>Methods</p> <p>We assessed each student 5 times over a period of 2 years. We used mixed effects modeling to examine change over time in enjoyment of PE.</p> <p>Results</p> <p>Enjoyment of PE declined among girls but remained constant among boys. Higher levels of perceived competence were associated with higher PE enjoyment. A 3-way interaction between gender, competence, and time revealed that PE enjoyment was lowest and declined most markedly among girls with low perceived athletic competence. Among boys with low competence, enjoyment remained at a consistently low level.</p> <p>Conclusions</p> <p>Our results indicate that lower perceived athletic competence is associated with low enjoyment of PE, and, among girls, with declining enjoyment. Findings suggest that interventions in a PE context that target perceived competence should be considered in future work.</p

    Discovery of frameshifting in Alphavirus 6K resolves a 20-year enigma.

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    BACKGROUND: The genus Alphavirus includes several potentially lethal human viruses. Additionally, species such as Sindbis virus and Semliki Forest virus are important vectors for gene therapy, vaccination and cancer research, and important models for virion assembly and structural analyses. The genome encodes nine known proteins, including the small '6K' protein. 6K appears to be involved in envelope protein processing, membrane permeabilization, virion assembly and virus budding. In protein gels, 6K migrates as a doublet--a result that, to date, has been attributed to differing degrees of acylation. Nonetheless, despite many years of research, its role is still relatively poorly understood. RESULTS: We report that ribosomal -1 frameshifting, with an estimated efficiency of approximately 10-18%, occurs at a conserved UUUUUUA motif within the sequence encoding 6K, resulting in the synthesis of an additional protein, termed TF (TransFrame protein; approximately 8 kDa), in which the C-terminal amino acids are encoded by the -1 frame. The presence of TF in the Semliki Forest virion was confirmed by mass spectrometry. The expression patterns of TF and 6K were studied by pulse-chase labelling, immunoprecipitation and immunofluorescence, using both wild-type virus and a TF knockout mutant. We show that it is predominantly TF that is incorporated into the virion, not 6K as previously believed. Investigation of the 3' stimulatory signals responsible for efficient frameshifting at the UUUUUUA motif revealed a remarkable diversity of signals between different alphavirus species. CONCLUSION: Our results provide a surprising new explanation for the 6K doublet, demand a fundamental reinterpretation of existing data on the alphavirus 6K protein, and open the way for future progress in the further characterization of the 6K and TF proteins. The results have implications for alphavirus biology, virion structure, viroporins, ribosomal frameshifting, and bioinformatic identification of novel frameshift-expressed genes, both in viruses and in cellular organisms

    Isoscalar electric multipole strength in C-12

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    Journals published by the American Physical Society can be found at http://publish.aps.org/The excitation region in C-12 below E-x=45 MeV was studied using 240 MeV alpha-particle scattering. Elastic scattering was measured from theta(c.m.)=3.8degrees to 49.4degrees and density dependant folding optical model parameters were obtained. Inelastic scattering to the 4.44 MeV 2(+), 7.65 MeV 0(+), 9.64 MeV 3(-), 10.3 MeV 0(+), and 10.84 MeV 1(-) states was measured and B(EL) values obtained. Inelastic scattering exciting C-12 to 10 MeVless than or equal toE(x)less than or equal to12.5 MeV was measured from 1.4degreesless than or equal totheta(c.m.)less than or equal to10degrees and to 12.5 MeVless than or equal toE(x)less than or equal to45 MeV from 1.4degreesless than or equal totheta(c.m.)less than or equal to16degrees and E0, E1, E2, and E3 strength distributions were obtained. Strength was identified corresponding to 27+/-5, 78+/-9, and 51+/-7% of the isoscalar E0, E1, and E2 energy weighted sum rule (EWSR), respectively, with centroids of 21.9+/-0.3, 27.5+/-0.4, and 22.6+/-0.5 MeV and rms widths of 4.8+/-0.5, 7.6+/-0.6, and 6.8+/-0.6 MeV. Less than 7% of the E3 EWSR strength was identified

    Isoscalar E0 strength between 6 and 11 MeV in Ca-40

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    Journals published by the American Physical Society can be found at http://publish.aps.org/The region from 6<E-x<11 MeV in Ca-40 has been studied with inelastic scattering of 240 MeV alpha particles at small angles including 0degrees . Strength corresponding to 3.2+/-1.0% of the isoscalar E0 sum rule was identified with a centroid of 8.7+/-0.30 MeV

    Isoscalar giant resonances for nuclei with mass between 56 and 60

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    Journals published by the American Physical Society can be found at http://publish.aps.org/The giant resonance region from 10 MeV < E-x < 62 MeV in Fe-56, Ni-58, and Ni-60 has been studied with inelastic scattering of 240 MeV alpha particles at small angles, including 0 degrees. Most of the expected isoscalar E0 and E2 strength has been identified below E-x = 40 MeV. Between 56 and 72% of the isoscalar E1 strength has been located in these nuclei. The mass dependence of the giant monopole energy between A = 40 and 90 is compared to relativistic and nonrelativistic calculations for interactions with compressibility of nuclear matter K-NM similar to 211-225 MeV

    Human MAIT cells respond to and suppress HIV-1

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    Human MAIT cells sit at the interface between innate and adaptive immunity, are polyfunctional and are capable of killing pathogen infected cells via recognition of the Class IB molecule MR1. MAIT cells have recently been shown to possess an antiviral protective role in vivo and we therefore sought to explore this in relation to HIV-1 infection. There was marked activation of MAIT cells in vivo in HIV-1-infected individuals, which decreased following ART. Stimulation of THP1 monocytes with R5 tropic HIVBAL potently activated MAIT cells in vitro. This activation was dependent on IL-12 and IL-18 but was independent of the TCR. Upon activation, MAIT cells were able to upregulate granzyme B, IFNγ and HIV-1 restriction factors CCL3, 4, and 5. Restriction factors produced by MAIT cells inhibited HIV-1 infection of primary PBMCs and immortalized target cells in vitro. These data reveal MAIT cells to be an additional T cell population responding to HIV-1, with a potentially important role in controlling viral replication at mucosal sites

    Haptoglobin Phenotype, Preeclampsia Risk and the Efficacy of Vitamin C and E Supplementation to Prevent Preeclampsia in a Racially Diverse Population

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    Haptoglobin's (Hp) antioxidant and pro-angiogenic properties differ between the 1-1, 2-1, and 2-2 phenotypes. Hp phenotype affects cardiovascular disease risk and treatment response to antioxidant vitamins in some non-pregnant populations. We previously demonstrated that preeclampsia risk was doubled in white Hp 2-1 women, compared to Hp 1-1 women. Our objectives were to determine whether we could reproduce this finding in a larger cohort, and to determine whether Hp phenotype influences lack of efficacy of antioxidant vitamins in preventing preeclampsia and serious complications of pregnancy-associated hypertension (PAH). This is a secondary analysis of a randomized controlled trial in which 10,154 low-risk women received daily vitamin C and E, or placebo, from 9-16 weeks gestation until delivery. Hp phenotype was determined in the study prediction cohort (n = 2,393) and a case-control cohort (703 cases, 1,406 controls). The primary outcome was severe PAH, or mild or severe PAH with elevated liver enzymes, elevated serum creatinine, thrombocytopenia, eclampsia, fetal growth restriction, medically indicated preterm birth or perinatal death. Preeclampsia was a secondary outcome. Odds ratios were estimated by logistic regression. Sampling weights were used to reduce bias from an overrepresentation of women with preeclampsia or the primary outcome. There was no relationship between Hp phenotype and the primary outcome or preeclampsia in Hispanic, white/other or black women. Vitamin supplementation did not reduce the risk of the primary outcome or preeclampsia in women of any phenotype. Supplementation increased preeclampsia risk (odds ratio 3.30; 95% confidence interval 1.61-6.82, p<0.01) in Hispanic Hp 2-2 women. Hp phenotype does not influence preeclampsia risk, or identify a subset of women who may benefit from vitamin C and E supplementation to prevent preeclampsia

    Circulating microRNAs Reveal Time Course of Organ Injury in a Porcine Model of Acetaminophen-Induced Acute Liver Failure

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    Acute liver failure is a rare but catastrophic condition which can progress rapidly to multi-organ failure. Studies investigating the onset of individual organ injury such as the liver, kidneys and brain during the evolution of acute liver failure, are lacking. MicroRNAs are short, non-coding strands of RNA that are released into the circulation following tissue injury. In this study, we have characterised the release of both global microRNA and specific microRNA species into the plasma using a porcine model of acetaminophen-induced acute liver failure. Pigs were induced to acute liver failure with oral acetaminophen over 19h±2h and death occurred 13h±3h thereafter. Global microRNA concentrations increased 4h prior to acute liver failure in plasma (P<0.0001) but not in isolated exosomes, and were associated with increasing plasma levels of the damage-associated molecular pattern molecule, genomic DNA (P<0.0001). MiR122 increased around the time of onset of acute liver failure (P<0.0001) and was associated with increasing international normalised ratio (P<0.0001). MiR192 increased 8h after acute liver failure (P<0.0001) and was associated with increasing creatinine (P<0.0001). The increase in miR124-1 occurred concurrent with the pre-terminal increase in intracranial pressure (P<0.0001) and was associated with decreasing cerebral perfusion pressure (P<0.002)

    Optimization of admixture and three-layer particleboard made from oil palm empty fruit bunch and rubberwood clones

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    Empty fruit bunch (EFB) is a biomass that is widely available and has the potential to be used as industrial raw material especially in wood-based industries. This study focuses on producing a particleboard by incorporating EFB with two different rubberwood clones: Prang Besar (PB) 260 and RRIM 2002, respectively. PB 260 is a commercially planted clone and wood from matured (>25 year-old) trees are used by wood-based panel manufacturers. RRIM 2002 is a new clone planted at the Malaysian Rubber Board (MRB) research trial plots and consists of only 4-year-old trees. Two types of particleboards (admixture and three-layer) with different ratios were produced. The Japanese Industrial Standard (JIS-5908 2003 particleboard) was used to evaluate mechanical and dimensional stability properties of the particleboards. From the study, it was found that admixture particleboards showed superior properties compared to three-layer particleboards. Layering EFB and rubberwood significantly decreased board performance for all properties (except internal bonding). The optimum ratios of EFB and both rubberwood clones are found to be 1:1 (50% EFB: 50% rubberwood). Meanwhile, increasing the rubberwood clones ratio to 70% lowered board performance especially for EFB (30%):RRIM 2002 clone (70%) boards which showed the lowest values for all properties for both admixture and three-layer board
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