The perception of effort during muscular fatigue and recovery

This study investigated how sense of effort is altered during fatigue in nine normal subjects. A contralateral limb matching paradigm was used in which the subjects nondominant (reference) arm was held at 20% MVC with force production matched at one minute intervals by the dominant (marching arm). It was found that matching force increased in a linear fashion with fatigue. It was also observed that EMG amplitude increased in the reference and matching arm and remained elevated during a 15 minute recovery period. As in previous studies strong correlation (r = 0.85) between rmsEMG in the reference arm and matching force was recorded. It was found that a subject was able to estimate force accurately a short time (in 10 minutes) after the fatiguing influence was removed although strength had not fully recovered. As with previous studies it was concluded that judgements of force production were based on the subjects internally generated perception of effort and not on the absolute force being generated

A note on fermions mesons in holographic QCD

We study the fermionic sector of a probe D8-brane in the supergravity background made of D4-branes compactified on a circle with supersymmetry broken explicitly by the boundary conditions. At low energies the dual field theory is effectively four-dimensional and has proved surprisingly successful in recovering qualitative and quantitative properties of QCD. We investigate fluctuations of the fermionic fields on the probe D8-brane and interpret these as mesinos (fermionic superpartners of mesons). We demonstrate that the masses of these modes are comparable to meson masses and show that their interactions with ordinary mesons are not suppressed

A Computational Methodology to Screen Activities of Enzyme Variants

We present a fast computational method to efficiently screen enzyme activity. In the presented method, the effect of mutations on the barrier height of an enzyme-catalysed reaction can be computed within 24 hours on roughly 10 processors. The methodology is based on the PM6 and MOZYME methods as implemented in MOPAC2009, and is tested on the first step of the amide hydrolysis reaction catalyzed by Candida Antarctica lipase B (CalB) enzyme. The barrier heights are estimated using adiabatic mapping and are shown to give barrier heights to within 3kcal/mol of B3LYP/6-31G(d)//RHF/3-21G results for a small model system. Relatively strict convergence criteria (0.5kcal/(mol{\AA})), long NDDO cutoff distances within the MOZYME method (15{\AA}) and single point evaluations using conventional PM6 are needed for reliable results. The generation of mutant structure and subsequent setup of the semiempirical calculations are automated so that the effect on barrier heights can be estimated for hundreds of mutants in a matter of weeks using high performance computing

Patients with ALS show highly correlated progression rates in left and right limb muscles.

ObjectiveAmyotrophic lateral sclerosis (ALS) progresses at different rates between patients, making clinical trial design difficult and dependent on large cohorts of patients. Currently, there are few data showing whether the left and right limbs progress at the same or different rates. This study addresses rates of decline in specific muscle groups of patients with ALS and assesses whether there is a relationship between left and right muscles in the same patient, regardless of overall progression.MethodsA large cohort of patients was used to assess decline in muscle strength in right and left limbs over time using 2 different methods: The Tufts Quantitative Neuromuscular Exam and Accurate Test of Limb Isometric Strength protocol. Then advanced linear regression statistical methods were applied to assess progression rates in each limb.ResultsThis report shows that linearized progression models can predict general slopes of decline with good accuracy. Critically, the data demonstrate that while overall decline is variable, there is a high degree of correlation between left and right muscle decline in ALS. This implies that irrespective of which muscle starts declining soonest or latest, their rates of decline following onset are more consistent.ConclusionsFirst, this study demonstrates a high degree of power when using unilateral treatment approaches to detect a slowing in disease progression in smaller groups of patients, thus allowing for paired statistical tests. These findings will be useful in transplantation trials that use muscle decline to track disease progression in ALS. Second, these findings discuss methods, such as tactical selection of muscle groups, which can improve the power efficiency of all ALS clinical trials

Modeling of internal tides in fjords

A previous model for the distribution of internal tides above irregular topography is generalized to include arbitrary stratification and a radiation condition at the open boundary. Thanks to a small amount of dissipation, this model remains valid in the presence of resonant internal tides, leading to intense wave-energy beams. An application to a Norwegian fjord correctly reproduces the observed energy pattern consisting of two beams both originating at the 60-meter deep entrance sill and extending in-fjord, one upward toward the surface, the other downward toward the bottom. After correction for the varying width of the fjord, the observed and modelled energy levels are in good agreement, especially in the upper levels where energy is the greatest. Furthermore, the substantial phase lag between these two energy beams revealed by the observations is correctly reproduced by the model. Finally, a third and very narrow energy spike is noted in the model at the level of a secondary bump inward of the sill. This beam is missed by the current meter data, because the current meters were placed only at a few selected depths. But an examination of the salinity profiles reveals a mixed layer at approximately the same depth. The explanation is that high-wave energy leads to wave breaking and vigorous mixing. The model\u27s greatest advantage is to provide the internal-tide energy distribution throughout the fjord. Discrepancies between observations and model are attributed to coarse vertical resolution in the vicinity of the sill and to unaccounted cross-fjord variations

Når jentene må inn i skapet: Seksuell trakassering og kjønnsfrihet i online dataspill

This article presents findings from a Norwegian research project on sexual harassment in online gaming. Based on an online survey (N=935) and expert interviews (N=8) with players, the authors examine sexual harassment, how it is performed, explained and with what consequences. The survey shows that sexually harassing language and behaviour is prevalent in games, but is also subject to controversy as many players code their activity as part of gameplay and not as a marginalizing process.Denne artikkelen presenterer funn fra et forskningsprosjekt om holdninger til kjønn, seksualitet og online-spill hos norske spillere. Forfatterne diskuterer spilleres forståelser av betydningen av trakasserende språkbruk og oppførsel i spill, og konsekvensene av seksuell trakassering på spillkulturnivå og aktørnivå gjennom en spørreundersøkelse og kvalitative intervju. Undersøkelsen viste at potensielt seksuelt trakasserende språkbruk er utbredt i spill, men også at det er stor uenighet blant spillere om hvorvidt slik språkbruk faktisk virker trakasserende, og hvorvidt det utgjør et problem. I artikkelen presenterer og diskuterer vi de to ulike synspunktene informantene har på seksuell trakassering i spill, og analyserer betydningen av at mange kvinnelige spillere holder skjuler informasjon om kjønn for å unngå seksuell trakassering.This article is downloaded from www.idunn.no. © 2015 Author(s). This is an Open Access article distributed under the terms of the Creative Commons CC-BY-NC 4.0 License (http://creativecommons.org/licenses/by-nc/4.0/), allowing third parties to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material for non-commercial use, provided the original author and source are credited

About the Dirac Equation with a δ\delta potential

An elementary treatment of the Dirac Equation in the presence of a three-dimensional spherically symmetric $\delta (r-r_0)$-potential is presented. We show how to handle the matching conditions in the configuration space, and discuss the occurrence of supercritical effects.Comment: 8 pages, 1 postscript figure, Latex, Revise

The N=8 Supergravity Hamiltonian as a Quadratic Form

We conjecture that the light-cone Hamiltonian of N=8 Supergravity can be expressed as a quadratic form. We explain why this rewriting is unique to maximally supersymmetric theories. The N=8 quartic interaction vertex is constructed and used to verify that this conjecture holds to second order in the coupling constant