1,614 research outputs found
Over egging the pudding? Comments on Ojala and Thorpe
In a recent paper in ISCJ, Ojala and Thorpe offered a culturally based observation that questions the role and application of coaching in action sports. Their critique is focused on the action sport of snowboarding which, despite its’ comparatively recent inclusion in the Olympics, retains a different, almost collaborative rather than competitive culture more akin to other action sports such as skateboarding and surfing. Ojala and Thorpe then present Problem Based Learning (PBL) as the solution to many of these perceived ills, describing the positive characteristics of the approach and promoting its cultural fit with action sport environments and performers. In this paper we offer a different perspective, which questions the veracity of the data presented and the unquestioningly positive view of PBL as the answer. Our alternative, data-driven perspective suggests that action sport athletes are increasingly positive, or even desirous of good coaching, of which PBL is a possible approach; suitable for some athletes some of the time
Uniqueness of human running coordination: The integration of modern and ancient evolutionary innovations
Running is a pervasive activity across human cultures and a cornerstone of contemporary health, fitness and sporting activities. Yet for the overwhelming predominance of human existence running was an essential prerequisite for survival. A means to hunt, and a means to escape when hunted. In a very real sense humans have evolved to run. Yet curiously, perhaps due to running’s cultural ubiquity and the natural ease with which we learn to run, we rarely consider the uniqueness of human bipedal running within the animal kingdom. Our unique upright, single stance, bouncing running gait imposes a unique set of coordinative difficulties. Challenges demanding we precariously balance our fragile brains in the very position where they are most vulnerable to falling injury while simultaneously retaining stability, steering direction of travel, and powering the upcoming stride: all within the abbreviated time-frames afforded by short, violent ground contacts separated by long flight times.
These running coordination challenges are solved through the tightly-integrated blending of primitive evolutionary legacies, conserved from reptilian and vertebrate lineages, and comparatively modern, more exclusively human, innovations. The integrated unification of these top-down and bottom-up control processes bestows humans with an agile control system, enabling us to readily modulate speeds, change direction, negotiate varied terrains and to instantaneously adapt to changing surface conditions.
The seamless integration of these evolutionary processes is facilitated by pervasive, neural and biological, activity-dependent adaptive plasticity. Over time, and with progressive exposure, this adaptive plasticity shapes neural and biological structures to best cope with regularly imposed movement challenges. This pervasive plasticity enables the gradual construction of a robust system of distributed coordinated control, comprised of processes that are so deeply collectively entwined that describing their functionality in isolation obscures their true irrevocably entangled nature.
Although other species rely on a similar set of coordinated processes to run, the bouncing bipedal nature of human running presents a specific set of coordination challenges, solved using a customized blend of evolved solutions.
A deeper appreciation of the foundations of the running coordination phenomenon promotes conceptual clarity, potentially informing future advances in running training and running-injury rehabilitation interventions
Putting the bumps in the rocky road: Optimising the pathway to excellence
There seems to be general agreement on the importance of challenge for effective development on the athlete pathway. What seems less coherent, however, are ideas on how much, when and how this challenge should be used. Reflecting our own experience as applied practitioners and our ongoing research, we offer a perspective on this work from a practitioner stance. The literature suggests that differences between levels of adult achievement relate more to what performers bring to the challenges than what they experience. Therefore, it is essential that young athletes have the opportunity to develop psycho-behavioural and coping skills, and have adequate social support, to ensure that adversity is interpreted as a positive growth experience. A periodized and progressive set of challenge, preceded with specific skill development, would seem to offer the best pathway to success. The importance of preparing athletes for challenges, supporting them through the experience, and then encouraging positive evaluation and reflection is key to successful outcome. Finally, we offer some suggestions, structures and systems which can be used to support the skill-based approach promoted
Using the Hopf Algebra Structure of QFT in Calculations
We employ the recently discovered Hopf algebra structure underlying
perturbative Quantum Field Theory to derive iterated integral representations
for Feynman diagrams. We give two applications: to massless Yukawa theory and
quantum electrodynamics in four dimensions.Comment: 28 p, Revtex, epsf for figures, minor changes, to appear in
Phys.Rev.
Isoform-selective susceptibility of DISC1/phosphodiesterase-4 complexes to dissociation by elevated intracellular cAMP levels
Disrupted-in-schizophrenia 1 (DISC1) is a genetic susceptibility factor for schizophrenia and related severe psychiatric conditions. DISC1 is a multifunctional scaffold protein that is able to interact with several proteins, including the independently identified schizophrenia risk factor phosphodiesterase-4B (PDE4B). Here we report that the 100 kDa full-length DISC1 isoform (fl-DISC1) can bind members of each of the four gene, cAMP-specific PDE4 family. Elevation of intracellular cAMP levels, so as to activate protein kinase A, caused the release of PDE4D3 and PDE4C2 isoforms from fl-DISC1 while not affecting binding of PDE4B1 and PDE4A5 isoforms. Using a peptide array strategy, we show that PDE4D3 binds fl-DISC1 through two regions found in common with PDE4B isoforms, the interaction of which is supplemented because of the presence of additional PDE4B-specific binding sites. We propose that the additional binding sites found in PDE4B1 underpin its resistance to release during cAMP elevation. We identify, for the first time, a functional distinction between the 100 kDa long DISC1 isoform and the short 71 kDa isoform. Thus, changes in the expression pattern of DISC1 and PDE4 isoforms offers a means to reprogram their interaction and to determine whether the PDE4 sequestered by DISC1 is released after cAMP elevation. The PDE4B-specific binding sites encompass point mutations in mouse Disc1 that confer phenotypes related to schizophrenia and depression and that affect binding to PDE4B. Thus, genetic variation in DISC1 and PDE4 that influence either isoform expression or docking site functioning may directly affect psychopathology
Medical student experiences in clinical reproductive medicine: dual-cohort assessment of a new learning module at the Royal College of Surgeons in Ireland
Aims: Exposure to a structured curriculum in reproductive medicine during medical school is helpful given the high frequency of fertility and pregnancy-related issues that future physicians will encounter. This study sought to evaluate a new reproductive medicine module for medical students. Study Design: Prospective cohort study. Place and Duration of Study: Dublin, Ireland; 2008-2010. Methodology: A new educational module in reproductive medicine for upper-level medical students was initiated in 2008 at the Royal College of Surgeons in Ireland (RCSI). The module included reproductive endocrinology lectures, laboratory sessions, and direct observation of clinical consultations as a required component of an obstetrics and gynaecology rotation. Students were assigned to this module on the basis of random allocation by departmental administration. The current investigation used an anonymous questionnaire and a MCQ exam to measure academic performance and student acceptance of this module, at launch and again two years later. The first sampling was from the pilot class in 2008 and a second group was evaluated in 2010. No student was in both groups. Results: 42 of 66 students completed the evaluation in 2008, and 71 of 98 did so in 2010. Mean±SD medical student age and average examination scores were comparable for the two groups. In both samples, most students (95.5%) had no prior lectures on reproductive endocrinology, and most indicated improvement in their level of understanding after the module. Both laboratory and clinical features were scored highly by students. Conclusion: At present, there is no standardised medical student curriculum for reproductive medicine in Ireland. This report is the first to describe a structured learning experience in this subspecialty area for medical students in Ireland. Additional studies are planned to track knowledge acquisition and career impact specific to reproductive medicine based on this module
Differential Equations for Definition and Evaluation of Feynman Integrals
It is shown that every Feynman integral can be interpreted as Green function
of some linear differential operator with constant coefficients. This
definition is equivalent to usual one but needs no regularization and
application of -operation. It is argued that presented formalism is
convenient for practical calculations of Feynman integrals.Comment: pages, LaTEX, MSU-PHYS-HEP-Lu2/9
Compact SAW aerosol generator
In this work, we discuss and demonstrate the principle features of surface acoustic wave (SAW) aerosol generation, based on the properties of the fluid supply, the acoustic wave field and the acoustowetting phenomena. Furthermore, we demonstrate a compact SAW-based aerosol generator amenable to mass production fabricated using simple techniques including photolithography, computerized numerical control (CNC) milling and printed circuit board (PCB) manufacturing. Using this device, we present comprehensive experimental results exploring the complexity of the acoustic atomization process and the influence of fluid supply position and geometry, SAW power and fluid flow rate on the device functionality. These factors in turn influence the droplet size distribution, measured here, that is important for applications including liquid chromatography, pulmonary therapies, thin film deposition and olfactory displays
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