713 research outputs found
A cross-sectional analysis of mental toughness in a professional football academy
This study investigated mental toughness in an English Premier League football academy. 112 football players aged between 12 and 18 years of age completed the Mental Toughness Questionnaire 18 (Clough, Earle, & Sewell, 2002) as a measure of mental toughness. A cross-sectional design was used to test for differences in mental toughness across age groups, and data concerning players who were either retained or released by the club was also compared. A one-way ANOVA showed no differences in mental toughness between age groups, and an independent t-test also found no differences in the mental toughness of players who were either retained or released. These results suggest that older and more experienced academy football players do not possess higher levels of mental toughness than younger, less experienced players. Qualitative research involving academy staff and players is encouraged to provide a more detailed evaluation
Quantum Fluctuations, Temperature and Detuning Effects in Solid-Light Systems
The superfluid to Mott insulator transition in cavity polariton arrays is
analyzed using the variational cluster approach, taking into account quantum
fluctuations exactly on finite length scales. Phase diagrams in one and two
dimensions exhibit important non-mean-field features. Single-particle
excitation spectra in the Mott phase are dominated by particle and hole bands
separated by a Mott gap. In contrast to Bose-Hubbard models, detuning allows
for changing the nature of the bosonic particles from quasi-localized excitons
to polaritons to weakly interacting photons. The Mott state with density one
exists up to temperatures , implying experimentally accessible
temperatures for realistic cavity couplings .Comment: 4 pages, 4 figures, to appear in Phys. Rev. Letter
On blocks of Deligne's category Rep(S_t)
Recently P. Deligne introduced the tensor category Rep(S_t) (for t not
necessarily an integer) which in a certain precise sense interpolates the
categories Rep(S_d) of representations of the symmetric groups S_d. In this
paper we describe the blocks of Deligne's category Rep(S_t).Comment: 43 pages, final version, includes an added appendix as well as other
modifications recommended by the refere
Akt isoforms in vascular disease.
The mammalian serine/threonine Akt kinases comprise three closely related isoforms: Akt1, Akt2 and Akt3. Akt activation has been implicated in both normal and disease processes, including in development and metabolism, as well as cancer and cardiovascular disease. Although Akt signalling has been identified as a promising therapeutic target in cancer, its role in cardiovascular disease is less clear. Importantly, accumulating evidence suggests that the three Akt isoforms exhibit distinct tissue expression profiles, localise to different subcellular compartments, and have unique modes of activation. Consistent with in vitro findings, genetic studies in mice show distinct effects of individual Akt isoforms on the pathophysiology of cardiovascular disease. This review summarises recent studies of individual Akt isoforms in atherosclerosis, vascular remodelling and aneurysm formation, to provide a comprehensive overview of Akt function in vascular disease.This work was supported by British Heart Foundation grants PG/11/
112/29272, RG/08/009/25841 and RG/13/14/30314, and the Cambridge
NIHR Biomedical Research Centre.This is the final version of the article. It was first published by Elsevier at http://www.sciencedirect.com/science/article/pii/S1537189115000397
Aerodynamic drag reduction of a simplified squareback vehicle using steady blowing
A large contribution to the aerodynamic drag of a
vehicle arises from the failure to fully recover pressure in the
wake region, especially on squareback configurations. A
degree of base pressure recovery can be achieved through
careful shape optimisation, but the freedom of an automotive
aerodynamicist to implement significant shape changes is
limited by a variety of additional factors such styling, ergonomics
and loading capacity. Active flow control technologies
present the potential to create flow field modifications
without the need for external shape changes and have
received much attention in previous years within the aeronautical
industry and, more recently, within the automotive
industry. In this work the influence of steady blowing applied
at a variety of angles on the roof trailing edge of a simplified
scale squareback style vehicle has been investigated. Hotwire
anemometry, force balance measurements, surface
pressure measurements and PIV have been used to investigate
the effects of the steady blowing on the vehicle wake
structures and the resulting body forces. The energy consumption
of the steady jet is calculated and is used to deduce
an aerodynamic drag power change. Results show that
overall gains can be achieved; however, the large mass flow
rate required restricts the applicability of the technique to
road vehicles. Means by which the mass flow rate requirements
of the jet may be reduced are discussed and suggestions
for further work put forward
Tissue Inhibitor of Metalloproteinase–3 (TIMP-3) induces FAS dependent apoptosis in human vascular smooth muscle cells
Over expression of Tissue Inhibitor of Metalloproteinases-3 (TIMP-3) in vascular smooth muscle cells (VSMCs) induces apoptosis and reduces neointima formation occurring after saphenous vein interposition grafting or coronary stenting. In studies to address the mechanism of TIMP-3-driven apoptosis in human VSMCs we find that TIMP-3 increased activation of caspase-8 and apoptosis was inhibited by expression of Cytokine response modifier A (CrmA) and dominant negative FAS-Associated protein with Death Domain (FADD). TIMP-3 induced apoptosis did not cause mitochondrial depolarisation, increase activation of caspase-9 and was not inhibited by over-expression of B-cell Lymphoma 2 (Bcl2), indicating a mitochondrial independent/type-I death receptor pathway. TIMP-3 increased levels of the First Apoptosis Signal receptor (FAS) and depletion of FAS with shRNA showed TIMP-3-induced apoptosis was FAS dependent. TIMP-3 induced formation of the Death-Inducing Signalling Complex (DISC), as detected by immunoprecipitation and by immunofluorescence. Cellular-FADD-like IL-1 converting enzyme-Like Inhibitory Protein (c-FLIP) localised with FAS at the cell periphery in the absence of TIMP-3 and this localisation was lost on TIMP-3 expression with c-FLIP adopting a perinuclear localisation. Although TIMP-3 inhibited FAS shedding, this did not increase total surface levels of FAS but instead increased FAS levels within localised regions at the cell surface. A Disintegrin And Metalloproteinase 17 (ADAM17) is inhibited by TIMP-3 and depletion of ADAM17 with shRNA significantly decreased FAS shedding. However ADAM17 depletion did not induce apoptosis or replicate the effects of TIMP-3 by increasing localised clustering of cell surface FAS. ADAM17-depleted cells could activate caspase-3 when expressing levels of TIMP-3 that were otherwise sub-apoptotic, suggesting a partial role for ADAM17 mediated ectodomain shedding in TIMP-3 mediated apoptosis. We conclude that TIMP-3 induced apoptosis in VSMCs is highly dependent on FAS and is associated with changes in FAS and c-FLIP localisation, but is not solely dependent on shedding of the FAS ectodomain
Quantum Monte Carlo results for bipolaron stability in quantum dots
Bipolaron formation in a two-dimensional lattice with harmonic confinement,
representing a simplified model for a quantum dot, is investigated by means of
quantum Monte Carlo simulations. This method treats all interactions exactly
and takes into account quantum lattice fluctuations. Calculations of the
bipolaron binding energy reveal that confinement opposes bipolaron formation
for weak electron-phonon coupling, but abets a bound state at intermediate to
strong coupling. Tuning the system from weak to strong confinement gives rise
to a small reduction of the minimum Frohlich coupling parameter for the
existence of a bound state.Comment: 5 pages, 2 figures, final version to appear in Phys. Rev.
An investigation into the wake structure of square back vehicles and the effect of structure modification on resultant vehicle forces
A large contribution to the aerodynamic drag of a vehicle (30%(1) or more depending on vehicle shape) arises from the low base pressure in the wake region, especially on square-back configurations. A degree of base pressure recovery can be achieved through careful shape optimization, but the flow structures and mechanisms within the wake that cause these base pressure changes are not well understood. A more complete understanding of these mechanisms may provide opportunities for further drag reductions from both passive shape changes and in the future through the use of active flow control technologies
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