25,566 research outputs found

    Cortical fMRI activation to opponents' body kinematics in sport-related anticipation: Expert-novice differences with normal and point-light video

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    This is the post-print version of the final paper published in Neuroscience Letters. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2011 Elsevier B.V.Badminton players of varying skill levels viewed normal and point-light video clips of opponents striking the shuttle towards the viewer; their task was to predict in which quadrant of the court the shuttle would land. In a whole-brain fMRI analysis we identified bilateral cortical networks sensitive to the anticipation task relative to control stimuli. This network is more extensive and localised than previously reported. Voxel clusters responding more strongly in experts than novices were associated with all task-sensitive areas, whereas voxels responding more strongly in novices were found outside these areas. Task-sensitive areas for normal and point-light video were very similar, whereas early visual areas responded differentially, indicating the primacy of kinematic information for sport-related anticipation.Research Grants Council of the Hong Kong Special Administrative Region, Chin

    A study of physico-chemical interactions between Haemophilus influenzae type b and meningococcus group C conjugate vaccines.

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    Background: Haemophilus influenzae type b (Hib) and Meningococcal group C (MenC) conjugate vaccines, which protect against otitis media, bacteremia and invasive diseases, including pneumonia and meningitis, are attractive candidates for combination, since they are both administered to infants and children. A Hib-MenC combination booster at 12 mo has recently been introduced in the U.K. Objectives: To rule out the possibility for the individual vaccine components in a Hib-MenC combination to interact, rendering one or both of them less effective, this work assessed whether these two saccharide-protein conjugates, namely, Hib oligosaccharide-CRM197 (Cross-Reacting Material 197) and MenC-CRM197, interact in solution. Furthermore an evaluation of the size and integrity of the vaccines was also performed. Methods: HPLC Size-exclusion chromatography (SEC) with UV-adsorption and refractive index detection was performed with a phosphate and non-phosphate saline buffer to characterize the size of Hib and MenC conjugates as individual components or when combined. Results: Hib-CRM197 eluted significantly earlier than MenC-CRM197 in both phosphate-saline and MOPS-saline buffers on a TSK5000 PWXL column. When combined, there was no significant change in their elution. Refractive index monitoring showed no evidence of significant free saccharide or free protein. Conclusions: By size-exclusion chromatography and refractive index detection methods, there was no indication of degradation, and no evidence of significant associative interactions between Hib-CRM197 and MenC-CRM197 in saline-based buffers, pH 7.2. African Health Sciences Vol. 7 (4) 2007: pp.190-19

    Local Volatility Calibration by Optimal Transport

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    The calibration of volatility models from observable option prices is a fundamental problem in quantitative finance. The most common approach among industry practitioners is based on the celebrated Dupire's formula [6], which requires the knowledge of vanilla option prices for a continuum of strikes and maturities that can only be obtained via some form of price interpolation. In this paper, we propose a new local volatility calibration technique using the theory of optimal transport. We formulate a time continuous martingale optimal transport problem, which seeks a martingale diffusion process that matches the known densities of an asset price at two different dates, while minimizing a chosen cost function. Inspired by the seminal work of Benamou and Brenier [1], we formulate the problem as a convex optimization problem, derive its dual formulation, and solve it numerically via an augmented Lagrangian method and the alternative direction method of multipliers (ADMM) algorithm. The solution effectively reconstructs the dynamic of the asset price between the two dates by recovering the optimal local volatility function, without requiring any time interpolation of the option prices

    Functional imaging of cortical responses in expert and novice badminton players while predicting the direction of a badminton stroke

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    This journal suppl. entitled: Special Issue: 15th Annual Meeting of the Organization for Human Brain MappingINTRODUCTION: Abernethy et al. (2008) showed that expert badminton players can use the kinematic information of the opponent's body movement to predict the direction of a stroke. The purpose of the present study was to compare the brain activity of expert and novice badminton players while carrying out a similar anticipation task. METHODS: In a block design fMRI study, participants viewed 2 s video displays of an opposing player, and pressed a button to indicate which of four possible court positions a stroke was directed. Individual trials were occluded either 80 ms before or 80ms after the ...postprin

    Systematic sample subdividing strategy for training landslide susceptibility models

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    © 2019 Elsevier B.V. Current practice in choosing training samples for landslide susceptibility modelling (LSM) is to randomly subdivide inventory information into training and testing samples. Where inventory data differ in distribution, the selection of training samples by a random process may cause inefficient training of machine learning (ML)/statistical models. A systematic technique may, however, produce efficient training samples that well represent the entire inventory data. This is particularly true when inventory information is scarce. This research proposed a systemic strategy to deal with this problem based on the fundamental distribution of probabilities (i.e. Hellinger) and a novel graphical representation of information contained in inventory data (i.e. inventory information curve, IIC). This graphical representation illustrates the relative increase in available information with the growth of the training sample size. Experiments on a selected dataset over the Cameron Highlands, Malaysia were conducted to validate the proposed methods. The dataset contained 104 landslide inventories and 7 landslide-conditioning factors (i.e. altitude, slope, aspect, land use, distance from the stream, distance from the road and distance from lineament) derived from a LiDAR-based digital elevation model and thematic maps acquired from government authorities. In addition, three ML/statistical models, namely, k-nearest neighbour (KNN), support vector machine (SVM) and decision tree (DT), were utilised to assess the proposed sampling strategy for LSM. The impacts of model's hyperparameters, noise and outliers on the performance of the models and the shape of IICs were also investigated and discussed. To evaluate the proposed method further, it was compared with other standard methods such as random sampling (RS), stratified RS (SRS) and cross-validation (CV). The evaluations were based on the area under the receiving characteristic curves. The results show that IICs are useful in explaining the information content in the training subset and their differences from the original inventory datasets. The quantitative evaluation with KNN, SVM and DT shows that the proposed method outperforms the RS and SRS in all the models and the CV method in KNN and DT models. The proposed sampling strategy enables new applications in landslide modelling, such as measuring inventory data content and complexity and selecting effective training samples to improve the predictive capability of landslide susceptibility models

    Relativistic Hydrodynamics with General Anomalous Charges

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    We consider the hydrodynamic regime of gauge theories with general triangle anomalies, where the participating currents may be global or gauged, abelian or non-abelian. We generalize the argument of arXiv:0906.5044, and construct at the viscous order the stress-energy tensor, the charge currents and the entropy current.Comment: 13 pages, Revte

    White blood cell count and risk of incident lung cancer in the UK Biobank

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    Background The contribution of measurable immunological/inflammatory parameters to lung cancer development remains unclear, particularly among never-smokers. We investigated the relationship between total and differential white blood cell (WBC) counts and incident lung cancer risk overall and among subgroups defined by smoking status and sex in the United Kingdom (UK). Methods We evaluated 424,407 adults aged 37-73 years from the UK Biobank. Questionnaires, physical measurements, and blood were administered/collected at baseline in 2006-2010. Complete blood cell counts were measured using standard methods. Lung cancer diagnoses and histological classifications were obtained from cancer registries. Multivariable Cox regression models were used to estimate the hazard ratio (HR) and 95% confidence intervals (CI) of incident lung cancer in relation to quartiles (Q) of total WBC and subtype-specific counts, with Q1 as the reference. Results There were 1,493 incident cases diagnosed over an average 7-year follow-up. Overall, the highest quartile of total WBC count was significantly associated with elevated lung cancer risk (HRQ4=1.67, 95% CI:1.41-1.98). Among women, increased risks were found in current-smokers (ncases/n=244/19,464, HRQ4=2.15, 95% CI:1.46-3.16), former-smokers (ncases/n=280/69,198, HRQ4=1.75, 95% CI:1.24-2.47), and never-smokers without environmental tobacco smoke exposure (ncases/n=108/111,294, HRQ4=1.93, 95% CI:1.11-3.35). Among men, stronger associations were identified in current-smokers (ncases/n=329/22,934, HRQ4=2.95, 95% CI:2.04-4.26) and former-smokers (ncases/n= 358/71,616, HRQ4=2.38, 95% CI:1.74-3.27) but not in never-smokers. Findings were similar for lung adenocarcinoma and squamous cell carcinoma and were driven primarily by elevated neutrophil fractions. Conclusions Elevated WBCs could potentially be one of many important markers for increased lung cancer risk, especially among never-smoking women and ever-smoking men

    Longitudinal Match Performance Characteristics of UK and Non-UK Players in the English Premier League

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    This study investigated the longitudinal match performance characteristics in the English Premier League (EPL), with special reference to player nationality (UK vs. non-UK). Match observations (n = 14700) were collected using a multi-camera computerised tracking system across 7 consecutive EPL seasons (2006–2007 to 2012– 2013). Player nationality referred to their birthplace, with players born in England, Scotland, Wales or Northern Ireland classified as the UK players and other nationalities considered non-UK. The non-UK players demon- strated the most pronounced increases in high-intensity running distance across the 7 seasons compared with UK players (P 0.05, ES: 0.08 [CI 0.01–0.15]). In contrast, the non-UK players performed more passes in 2006–2007 compared with the UK players (P 0.05, ES: 0.05 [CI −0.01–0.13]). The data demonstrates that the longitudinal match performance characteristics in the EPL are similar between the UK and non-UK populations

    Evolution of match performance parameters for various playing positions in the English Premier League

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    This study aimed to investigate position-specific evolution of physical and technical performance parameters in the English Premier League (EPL). Match performance observations (n = 14700) were collected using a multiple-camera computerized tracking system across seven seasons (2006–07 to 2012–13). Data were analyzed relative to five playing positions: central defenders (n = 3792), full backs (n = 3420), central midfielders (n = 3200), wide midfielders (n = 2136) and attackers (n = 2152). High-intensity running distance increased in the final season versus the first season in all playing positions (p < .05, ES: 0.9–1.3) with full backs displaying the greatest increase (∼36% higher in 2012–13). Similar trends were observed for sprint distance with full backs demonstrating the most pronounced increase across the seven seasons (36–63%, p < .001, ES: 0.8–1.3). Central players (central defenders and midfielders) illustrated the most pronounced increases in total passes and pass success rate (p < .05, ES: 0.7–0.9) whilst wide players (full backs and wide midfielders) demonstrated only small-moderate increases in total passes and pass success rate (p < .05, ES: 0.6–0.8). The data demonstrates that evolving tactics in the EPL have impacted on the physical demands of wide players and the technical requirements of central players. These findings could be used for talent identification or position-specific physical and technical training
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