Preventing the seemingly unpreventable – challenging the return-to-play criteria for recurrent hamstring strain prevention

Background: Hamstring strains are one of the most common injuries in sport. Previous injury has been found to be one of the greatest risk factors associated with recurrent hamstring strains. Although rehabilitation programmes have been developed and implemented to aid safe and efficient return-to-play, the incidence of hamstring injuries has not decreased.Discussion: As hamstring strains most commonly occur during the eccentric phase of muscle action, rehabilitation should focus on eccentric muscle strengthening. The L-protocol and the Nordic Hamstring Exercise protocol strengthen the hamstring muscles eccentrically. They have been found to be effective in decreasing the incidence of new hamstring strains as well as the rate of recurrence. This commentary therefore aims to suggest changes to the return-to-play criteria following hamstring strains to prevent the seemingly unpreventable.Keywords: hamstrings, injury prevention, sports, eccentric movemen

Hungary: Liquidity Scheme

Amid the global credit crunch in late 2008, foreign investors dumped Hungarian assets, the Hungarian forint (HUF) depreciated, and liquidity deteriorated in the Hungarian banking sector due to the prevalence of short-term, foreign currency-denominated liabilities. On March 10, 2009, the Hungarian government established a scheme to provide up to HUF 1.1 trillion (USD 4.9 billion) in foreign exchange liquidity to domestic credit institutions and subsidiaries of foreign banks. The government used funds provided by the International Monetary Fund (IMF) and European Union (EU) in October 2008, a USD 25.1 billion package to provide Hungary with sufficient foreign exchange reserves to meet broad external, foreign-currency obligations. Earlier efforts to establish voluntary guarantees and recapitalizations for Hungarian banks using the IMF-EU funds were unsuccessful, and markets remained concerned about the liquidity of Hungary’s banks. By January 2010, the liquidity scheme had lent HUF 690 billion (USD 3 billion) to three domestic banks. Over the next four years, the EC repeatedly reapproved the scheme for six-month extensions, although the facility did not originate any further loans. The scheme was finally allowed to expire on June 30, 2013

Avalanche statistics of sand heaps

Large scale computer simulations are presented to investigate the avalanche statistics of sand piles using molecular dynamics. We could show that different methods of measurement lead to contradicting conclusions, presumably due to avalanches not reaching the end of the experimental table.Comment: 6 pages, 4 figure

Preventing the seemingly unpreventable – challenging the return-to-play criteria for recurrent hamstring strain prevention

   Background: Hamstring strains are one of the most common injuries in sport. Previous injury has been found to be one of the greatest risk factors associated with recurrent hamstring strains. Although rehabilitation programmes have been developed and implemented to aid safe and efficient return-to-play, the incidence of hamstring injuries has not decreased.  Discussion: As hamstring strains most commonly occur during the eccentric phase of muscle action, rehabilitation should focus on eccentric muscle strengthening. The L-protocol and the Nordic Hamstring Exercise protocol strengthen the hamstring muscles eccentrically. They have been found to be effective in decreasing the incidence of new hamstring strains as well as the rate of recurrence. This commentary therefore aims to suggest changes to the return-to-play criteria following hamstring strains to prevent the seemingly unpreventable

Two phase transitions in (s+id)-wave Bardeen-Cooper-Schrieffer superconductivity

We establish universal behavior in temperature dependencies of some observables in $(s+id)$-wave BCS superconductivity in the presence of a weak $s$ wave. There also could appear a second second-order phase transition. As temperature is lowered past the usual critical temperature $T_c$, a less ordered superconducting phase is created in $d$ wave, which changes to a more ordered phase in $(s+id)$ wave at $T_{c1}$ ($< T_c$). The presence of two phase transitions manifest in two jumps in specific heat at $T_c$ and $T_{c1}$. The temperature dependencies of susceptibility, penetration depth, and thermal conductivity also confirm the new phase transition.Comment: 6 pages, 5 post-script figures

Tunneling into Current-Carrying Surface States of High Tc_c Superconductors

Theoretical results for the ab-plane tunneling conductance in the d-wave model for high Tc superconductors are presented. The d-wave model predicts surface bound states below the maximum gap. A sub-dominant order parameter, stabilized by the surface, leads to a splitting of the zero-bias conductance peak (ZBCP) in zero external field and to spontaneous surface currents. In a magnetic field screening currents shift the quasiparticle bound state spectrum and lead to a voltage splitting of the ZBCP that is linear in H at low fields, and saturates at a pairbreaking critical field of order 3 Tesla. Comparisons with recent experimental results on Cu/YBCO junctions are presented.Comment: 4 pages in a RevTex (3.0) file plus 3 Figures in PostScript. To appear in Phys. Rev. Let

Temporal Partitioning and Overlapping Use of a Shared Natural Resource by People and Elephants

In social-ecological systems around the world, human-wildlife interactions are on the rise, often with negative consequences. This problem is particularly salient in areas where populations of humans and wildlife are increasing and share limited space and resources. However, few studies look at how both people and wildlife navigate shared spaces. To better examine people and wildlife within the same environment, we used methods from social science and spatial ecology to investigate how humans and elephants in Botswana utilize trees, a shared natural resource. Trees provide an opportunity to study shared resource use because they are important for people as firewood and for elephants as food and habitat. We compared tree species gathered on 49 firewood collections with the species damaged by elephants in 83 vegetation plots. We found that many tree species were damaged by elephants in ways that would generate firewood. There was also a strong overlap in the tree species that people collected and the species that elephants browsed and/or damaged. We compared spatially-explicit firewood collection locations and movement data from elephant GPS collars to model resource selection by people and elephants. Proximity to settlements was a strong driving factor for people in firewood collection, while various factors including vegetation characteristics played a role in predicting elephant movement. We found that areas where people collect firewood were negatively correlated with daytime elephant movement and positively correlated with nighttime elephant movement. We further compared the times that people collected firewood with the times when elephants were near the villages and found that people collected firewood during daylight hours when elephants were not nearby, providing further evidence of temporal partitioning. People and elephants utilized the same species of trees, and also had correlated spatial patterns of resource selection. Therefore, elephant foraging of trees provides a previously unrecognized utility to people in the form of firewood creation, and temporal partitioning allows this to occur without direct human-elephant interaction

Nuclear spin-lattice relaxation rate in the D+iD superconducting state: implications for CoO superconductor

We calculated the nuclear spin-lattice relaxation rate $1/T_1$ for the D+iD superconducting state with impurities. We found that small amount of unitary impurities quickly produces the residual density of states inside the gap. As a result, the T-linear behavior in 1/T$_1$ is observed at low temperatures. Our results show that the D+iD pairing symmetry of the superconducting state of Na$_{0.35}$CoO$_{2} \cdot y$H$_2$ O is compatible with recent $^{59}$Co 1/T$_1$ experiments of several groups.Comment: 5 pages, 4 figures, minor change

The effect of the contract-relax-antagonist-contract (CRAC) stretch of hamstrings on range of motion, sprint and agility performance in moderately active males: A randomised control trial

Background: Although stretching is done routinely to prevent injury during explosive sport activities, there is some concern that effective stretching might negatively impact on performance. Objectives: This study’s main objective was to investigate the impact of a specific stretch (CRAC), in which the muscle to be stretched, hamstrings, is actively contracted then relaxed. This is then followed by the antagonist muscle (quadriceps) contracting. Secondly, the impact of the stretch on performance was examined. Methods: A randomised control trial was used. Forty healthy active males between 21 and 35 years of age were assigned to either receive three repetitions of CRAC or rest. Hamstring flexibility and the Illinois Agility Test were the primary outcome measures. Results: The intervention was effective in improving hamstring flexibility by 37% immediately post-application and this was maintained for eight minutes thereafter. It had no significant effect on agility or sprint times. Conclusions: CRAC applied to stretch the hamstring muscles of active males resulted in a large increase of active knee extension range of motion, without decreasing performance. CRAC appears to be a safe and effective method of increasing the length of the hamstrings pre-sport activity and should be utilised by sports physiotherapists if deemed necessary and beneficial following initial assessment

Thermodynamic Potential for Superfluid 3He in Aerogel

We present a free energy functional for superfluid 3He in the presence of homogeneously distributed impurity disorder which extends the Ginzburg-Landau free energy functional to all temperatures. We use the new free energy functional to calculate the thermodynamic potential, entropy, heat capacity and density of states for the B-phase of superfluid 3He in homogeneous, isotropic aerogel.Comment: 10 pages, 4 figure