389 research outputs found

    Biomechanical predictors of ball velocity during punt kicking in elite rugby league kickers

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    Punt kicking is integral to the attacking and defensive elements of rugby league and the ability to kick the ball with high velocity is desirable. This study aimed to identify important technical aspects of kicking linked to the generation of ball velocity. Maximal punt kicks were obtained from six elite rugby league kickers using a 10-camera motion capture system. Three-dimensional kinematics of the lower extremities was obtained. Regression analysis with ball velocity as criterion was used to identify the kinematic parameters associated with the development of ball velocity. The regression model yielded an adj R2¼0.76, p�0.01. Two parameters were identified: knee extension angular velocity of the kicking limb at impact (R2¼0.50) and peak flexion angular velocity of the kicking hip (R2¼0.26, p�0.01). It is conceivable that players may benefit from exposure to coaching and strength techniques geared toward the modification of kicking mechanics specific to this stud

    Glucocorticoid Receptor 1B and 1C mRNA Transcript Alterations in Schizophrenia and Bipolar Disorder, and Their Possible Regulation by GR Gene Variants

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    Abnormal patterns of HPA axis activation, under basal conditions and in response to stress, are found in individuals with schizophrenia and bipolar disorder. Altered glucocorticoid receptor (GR) mRNA and protein expression in the dorsolateral prefrontal cortex (DLPFC) in psychiatric illness have also been reported, but the cause of these abnormalities is not known. We quantified expression of GR mRNA transcript variants which employ different 5′ promoters, in 35 schizophrenia cases, 31 bipolar disorder cases and 34 controls. We also explored whether sequence variation within the NR3C1 (GR) gene is related to GR mRNA variant expression. Total GR mRNA was decreased in the DLPFC in schizophrenia cases relative to controls (15.1%, p<0.0005) and also relative to bipolar disorder cases (8.9%, p<0.05). GR-1B mRNA was decreased in schizophrenia cases relative to controls (20.2%, p<0.05), while GR-1C mRNA was decreased in both schizophrenia and bipolar disorder cases relative to controls (16.1% and 17.2% respectively, both p<0.005). A dose-dependent effect of rs10052957 genotype on GR-1B mRNA expression was observed, where CC homozygotes displayed 18.4% lower expression than TC heterozygotes (p<0.05), and 31.8% lower expression than TT homozygotes (p<0.005). Similarly, a relationship between rs6190 (R23K) genotype and GR-1C expression was seen, with 24.8% lower expression in GG homozygotes than GA heterozygotes (p<0.01). We also observed an effect of rs41423247 (Bcl1) SNP on expression of 67 kDa GRα isoform, the most abundant GRα isoform in the DLPFC. These findings suggest possible roles for the GR-1B and GR-1C promoter regions in mediating GR gene expression changes in psychotic illness, and highlight the potential importance of sequence variation within the NR3C1 gene in modulating GR mRNA expression in the DLPFC

    Angular and Current-Target Correlations in Deep Inelastic Scattering at HERA

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    Correlations between charged particles in deep inelastic ep scattering have been studied in the Breit frame with the ZEUS detector at HERA using an integrated luminosity of 6.4 pb-1. Short-range correlations are analysed in terms of the angular separation between current-region particles within a cone centred around the virtual photon axis. Long-range correlations between the current and target regions have also been measured. The data support predictions for the scaling behaviour of the angular correlations at high Q2 and for anti-correlations between the current and target regions over a large range in Q2 and in the Bjorken scaling variable x. Analytic QCD calculations and Monte Carlo models correctly describe the trends of the data at high Q2, but show quantitative discrepancies. The data show differences between the correlations in deep inelastic scattering and e+e- annihilation.Comment: 26 pages including 10 figures (submitted to Eur. J. Phys. C

    Plastisol Foaming Process. Decomposition of the Foaming Agent, Polymer Behavior in the Corresponding Temperature Range and Resulting Foam Properties

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    The decomposition of azodicarbonamide, used as foaming agent in PVC - plasticizer (1/1) plastisols was studied by DSC. Nineteen different plasticizers, all belonging to the ester family, two being polymeric (polyadipates), were compared. The temperature of maximum decomposition rate (in anisothermal regime at 5 K min-1 scanning rate), ranges between 434 and 452 K. The heat of decomposition ranges between 8.7 and 12.5 J g -1. Some trends of variation of these parameters appear significant and are discussed in terms of solvent (matrix) and viscosity effects on the decomposition reactions. The shear modulus at 1 Hz frequency was determined at the temperature of maximum rate of foaming agent decomposition, and differs significantly from a sample to another. The foam density was determined at ambient temperature and the volume fraction of bubbles was used as criterion to judge the efficiency of the foaming process. The results reveal the existence of an optimal shear modulus of the order of 2 kPa that corresponds roughly to plasticizer molar masses of the order of 450 ± 50 g mol-1. Heavier plasticizers, especially polymeric ones are too difficult to deform. Lighter plasticizers such as diethyl phthalate (DEP) deform too easily and presumably facilitate bubble collapse

    Thinking about going to the dentist: a Contemplation Ladder to assess dentally-avoidant individuals' readiness to go to a dentist

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    <p>Abstract</p> <p>Background</p> <p>The Transtheoretical Model suggests that individuals vary according to their readiness to change behavior. Previous work in smoking cessation and other health areas suggests that interventions are more successful when they are tailored to an individual's stage of change with regards to the specific behavior. We report on the performance of a single-item measure ("Ladder") to assess the readiness to change dental-avoidant behavior.</p> <p>Methods</p> <p>An existing Contemplation Ladder for assessing stage of change in smoking cessation was modified to assess readiness to go to a dentist. The resulting Ladder was administered to samples of English-speaking adolescents (USA), Spanish-speaking adults (USA), and Norwegian military recruits (Norway) in order to assess construct validity. The Ladder was also administered to a sample of English-speaking avoidant adolescents and young adults who were enrolled in an intervention study (USA) in order to assess criterion validity. All participants also had dental examinations, and completed other questionnaires. Correlations, chi square, t tests and one-way ANOVAs were used to assess relationships between variables.</p> <p>Results</p> <p>In two samples, participants who do not go to the dentist had significantly more teeth with caries; in a third sample, participants who do not go to the dentist had significantly worse caries. Ladder scores were not significantly related to age, gender, caries, or dental fear. However, Ladder scores were significantly related to statements of intention to visit a dentist in the future and the importance of oral health. In a preliminary finding, Ladder scores at baseline also predicted whether or not the participants decided to go to a dentist in the intervention sample.</p> <p>Conclusions</p> <p>The data provide support for the convergent and divergent construct validity of the Ladder, and preliminary support for its criterion validity. The lack of relationship between dental fear and Ladder scores suggests that avoidant individuals may be helped to decide to go to a dentist using interventions which do not explicitly target their fear.</p

    Molecular Characterization of the Region 7q22.1 in Splenic Marginal Zone Lymphomas

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    Splenic marginal zone lymphomas (SMZL) are an uncommon type of B-cell non-Hodgkin's lymphoma (NHL-B) in which no specific chromosomal translocations have been described. In contrast, the most frequent cytogenetic abnormality is the loss of the long arm of chromosome 7 (7q). Previous reports have located this loss in the 7q32 region. In order to better characterize the genomic imbalances in SMZL, molecular studies were carried out in 73 patients with SMZL. To gain insight into the mapping at 7q a tiling array was also used. The results confirmed the loss of 7q as the most frequent change. In addition, several abnormalities, including 4q22.1, 1q21.3–q22, 6q25.3, 20q13.33, 3q28, 2q23.3–q24.1 and 17p13, were also present. A loss of 7q22.1 at 99925039–101348479 bp was observed in half of the cases. The region of 7q22.1 has not previously been characterised in SMZL. Our results confirmed the presence of a new region of loss on chromosome 7 in these NHL

    Radiosensitizing potential of the selective cyclooygenase-2 (COX-2) inhibitor meloxicam on human glioma cells

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    The COX-2 protein is frequently overexpressed in human malignant gliomas. This expression has been associated with their aggressive growth characteristics and poor prognosis for patients. Targeting the COX-2 pathway might improve glioma therapy. In this study, the effects of the selective COX-2 inhibitor meloxicam alone and in combination with irradiation were investigated on human glioma cells in vitro. A panel of three glioma cell lines (D384, U87 and U251) was used in the experiments from which U87 cells expressed constitutive COX-2. The response to meloxicam and irradiation (dose-range of 0–6 Gy) was determined by the clonogenic assay, cell proliferation was evaluated by growth analysis and cell cycle distribution by FACS. 24–72 h exposure to 250–750 μM meloxicam resulted in a time and dose dependent growth inhibition with an almost complete inhibition after 24 h for all cell lines. Exposure to 750 μM meloxicam for 24 h increased the fraction of cells in the radiosensitive G2/M cell cycle phase in D384 (18–27%) and U251 (17–41%) cells. 750 μM meloxicam resulted in radiosensitization of D384 (DMF:2.19) and U87 (DMF:1.25) cells, but not U251 cells (DMF:1.08). The selective COX-2 inhibitor meloxicam exerted COX-2 independent growth inhibition and radiosensitization of human glioma cells

    Turnover of Sex Chromosomes in the Stickleback Fishes (Gasterosteidae)

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    Diverse sex-chromosome systems are found in vertebrates, particularly in teleost fishes, where different systems can be found in closely related species. Several mechanisms have been proposed for the rapid turnover of sex chromosomes, including the transposition of an existing sex-determination gene, the appearance of a new sex-determination gene on an autosome, and fusions between sex chromosomes and autosomes. To better understand these evolutionary transitions, a detailed comparison of sex chromosomes between closely related species is essential. Here, we used genetic mapping and molecular cytogenetics to characterize the sex-chromosome systems of multiple stickleback species (Gasterosteidae). Previously, we demonstrated that male threespine stickleback fish (Gasterosteus aculeatus) have a heteromorphic XY pair corresponding to linkage group (LG) 19. In this study, we found that the ninespine stickleback (Pungitius pungitius) has a heteromorphic XY pair corresponding to LG12. In black-spotted stickleback (G. wheatlandi) males, one copy of LG12 has fused to the LG19-derived Y chromosome, giving rise to an X1X2Y sex-determination system. In contrast, neither LG12 nor LG19 is linked to sex in two other species: the brook stickleback (Culaea inconstans) and the fourspine stickleback (Apeltes quadracus). However, we confirmed the existence of a previously reported heteromorphic ZW sex-chromosome pair in the fourspine stickleback. The sex-chromosome diversity that we have uncovered in sticklebacks provides a rich comparative resource for understanding the mechanisms that underlie the rapid turnover of sex-chromosome systems

    Development of a cDNA microarray for the measurement of gene expression in the sheep scab mite Psoroptes ovis

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    Background: Sheep scab is caused by the ectoparasitic mite Psoroptes ovis which initiates a profound cutaneous inflammatory response, leading to the development of the skin lesions which are characteristic of the disease. Existing control strategies rely upon injectable endectocides and acaricidal dips but concerns over residues, eco-toxicity and the development of acaricide resistance limit the sustainability of this approach. In order to identify alternative means of disease control, a deeper understanding of both the parasite and its interaction with the host are required. Methods: Herein we describe the development and utilisation of an annotated P. ovis cDNA microarray containing 3,456 elements for the measurement of gene expression in this economically important ectoparasite. The array consists of 981 P. ovis EST sequences printed in triplicate along with 513 control elements. Array performance was validated through the analysis of gene expression differences between fed and starved P. ovis mites. Results: Sequences represented on the array include homologues of major house dust mite allergens and tick salivary proteins, along with factors potentially involved in mite reproduction and xenobiotic metabolism. In order to validate the performance of this unique resource under biological conditions we used the array to analyse gene expression differences between fed and starved P. ovis mites. These analyses identified a number of house dust mite allergen homologues up-regulated in fed mites and P. ovis transcripts involved in stress responses, autophagy and chemosensory perception up-regulated in starved mites. Conclusion: The P. ovis cDNA microarray described here has been shown to be both robust and reproducible and will enable future studies to analyse gene expression in this important ectoparasite
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