Effects of Isolated Hip Abductor Fatigue on Frontal Plane Knee Mechanics

Purpose: Anterior cruciate ligament injuries and patellofemoral pain syndrome are both common and significant injuries to the knee that have been associated with hip weakness. Prospective studies have linked the risk of experiencing either injury to alterations in the frontal plane knee angle and moment during activity. These components of knee mechanics are theorized to be affected by hip abductor weakness. The purpose of this study was to identify the effects of isolated hip abductor fatigue-induced weakness on lower extremity kinematics and kinetics in recreationally active women

Hip External Rotator Strength Is Associated With Better Dynamic Control of the Lower Extremity During Landing Tasks

Hip external rotator strength is associated with better dynamic control of the lower extremity during landing tasks. J Strength Cond Res 30(1): 282–291, 2016—The purpose of this study was to determine the association between hip strength and lower extremity kinematics and kinetics during unanticipated single-leg landing and cutting tasks in collegiate female soccer players. Twenty-three National Collegiate Athletic Association division I female soccer players were recruited for strength testing and biomechanical analysis. Maximal isometric hip abduction and external rotation strength were measured using a hand-held dynamometer and expressed as muscle torque (force × femoral length) and normalized to body weight. Three-dimensional lower extremity kinematics and kinetics were assessed with motion analysis and force plates, and an inverse dynamics approach was used to calculate net internal joint moments that were normalized to body weight. Greater hip external rotator strength was significantly associated with greater peak hip external rotation moments (r = 0.47; p = 0.021), greater peak knee internal rotation moments (r = 0.41; p = 0.048), greater hip frontal plane excursion (r = 0.49; p = 0.017), and less knee transverse plane excursion (r = -0.56; p = 0.004) during unanticipated single-leg landing and cutting tasks. In addition, a statistical trend was detected between hip external rotator strength and peak hip frontal plane moments (r = 0.39; p = 0.06). The results suggest that females with greater hip external rotator strength demonstrate better dynamic control of the lower extremity during unanticipated single-leg landing and cutting tasks and provide further support for the link between hip strength and lower extremity landing mechanics

Charm, Beauty and Top at HERA

Results on open charm and beauty production and on the search for top production in high-energy electron-proton collisions at HERA are reviewed. This includes a discussion of relevant theoretical aspects, a summary of the available measurements and measurement techniques, and their impact on improved understanding of QCD and its parameters, such as parton density functions and charm- and beauty-quark masses. The impact of these results on measurements at the LHC and elsewhere is also addressed.Comment: 103 pages, 60 figures, to be published in Prog. Part. Nucl. Phy

First record of the family Cantharidae on Socotra, with description of a new genus and two new species of the subfamily Silinae (Coleoptera: Elateroidea)

The papers published in Acta Entomologica Musei Nationalis Pragae are open access. The attached file is the published version of the article.NHM Repositor

Anticipatory Effects on Lower Extremity Neuromechanics During a Cutting Task

Context: Continued research into the mechanism of noncontact anterior cruciate ligament injury helps to improve clinical interventions and injury-prevention strategies. A better understanding of the effects of anticipation on landing neuromechanics may benefit training interventions. Objective: To determine the effects of anticipation on lower extremity neuromechanics during a single-legged land-and-cut task. Design: Controlled laboratory study. Setting: University biomechanics laboratory. Participants: Eighteen female National Collegiate Athletic Association Division I collegiate soccer players (age = 19.7 ± 0.8 years, height = 167.3 ± 6.0 cm, mass = 66.1 ± 2.1 kg). Intervention(s): Participants performed a single-legged land-and-cut task under anticipated and unanticipated conditions. Main Outcome Measure(s): Three-dimensional initial contact angles, peak joint angles, and peak internal joint moments and peak vertical ground reaction forces and sagittal-plane energy absorption of the 3 lower extremity joints; muscle activation of selected hip- and knee-joint muscles. Results: Unanticipated cuts resulted in less knee flexion at initial contact and greater ankle toe-in displacement. Unanticipated cuts were also characterized by greater internal hip-abductor and external-rotator moments and smaller internal knee-extensor and external-rotator moments. Muscle-activation profiles during unanticipated cuts were associated with greater activation of the gluteus maximus during the precontact and landing phases. Conclusions: Performing a cutting task under unanticipated conditions changed lower extremity neuromechanics compared with anticipated conditions. Most of the observed changes in lower extremity neuromechanics indicated the adoption of a hip-focused strategy during the unanticipated condition

The Association of Dorsiflexion Flexibility on Knee Kinematics and Kinetics during a Drop Vertical Jump in Healthy Female Athletes

Purpose While previous studies have examined the association between ankle dorsiflexion flexibility and deleterious landing postures, it is not currently known how landing kinetics are influenced by ankle dorsiflexion flexibility. The purpose of this study was to examine whether ankle dorsiflexion flexibility was associated with landing kinematics and kinetics that have been shown to increase the risk of anterior cruciate ligament (ACL) injury in female athletes. Methods Twenty-three female collegiate soccer players participated in a preseason screening that included the assessment of ankle dorsiflexion flexibility and lower-body kinematics and kinetics during a drop vertical jump task. Results The results demonstrated that females with less ankle dorsiflexion flexibility exhibited greater peak knee abduction moments (r = −.442), greater peak knee abduction angles (r = .355), and less peak knee flexion angles (r = .385) during landing. The range of dorsiflexion flexibility for the current study was between 9° and 23° (mean = 15.0°; SD 3.9°). Conclusion Dorsiflexion flexibility may serve as a useful clinical measure to predict poor landing postures and external forces that have been associated with increased knee injury risk. Rehabilitation specialists can provide interventions aimed at improving dorsiflexion flexibility in order to ameliorate the impact of this modifiable factor on deleterious landing kinematics and kinetics in female athletes

Clonality, recombination, and hybridization in the plumbing-inhabiting human pathogen Fusarium keratoplasticum inferred from multilocus sequence typing

Sammanfattning/AbstractHelene Erös och Jennie Karlsson (2013). Action programs as tool for learning.Specialpedagogprogrammet 90hp Skolutveckling och ledarskap Lärande och samhälle, Malmö högskolaProblemområde: Skolverket (2012) presenterade nyligen de senaste resultaten från PIRLS och TIMMS. De visade att Sveriges elever i årskurs 4 hade försämrats inom läsning och i matematik hade de lägre resultat än andra EU/OECD länder. Detta är alarmerande och måste tas på allvar. Sämre resultat leder på sikt till att fler och fler åtgärdsprogram behöver utfärdas. Det är viktigt att åtgärdsprogrammen fungerar som redskap för att motverka de negativa utvecklingstrenderna.Syfte: Syftet med vår undersökning var att undersöka åtgärdsprogram som verktyg för lärande. Med hjälp av våra frågeställningar belyste vi åtgärdsprogram ur flera perspektiv. De var blanketternas utformning och innehåll, synen på lärande i åtgärderna och hur lärare arbetar med åtgärdsprogram i undervisningen. Teoretisk ram: I arbetet utgick vi från två teorier om lärande, kognitiv konstruktivism och social konstruktivism. Vi använde även teori utifrån det sociokulturella perspektivet. Tidigare forskning kring åtgärdsprogram och riktlinjer från lagar, läroplaner och allmänna råd bildade en bakgrund.Metod: Vi valde att göra en kvalitativ innehållsanalys av åtgärdsprogram och halvstrukturerade intervjuer med fyra lärare från två kommuner.Resultat med analys: Våra resultat visar att begrepp i åtgärdsprogrammen som styrkor eller organisation, grupp och individ tolkas olika av lärare. Målen är överlag svåra för eleven att uppnå inom en rimlig tid och det är vanligt att målformuleringarna är otydliga. Åtgärderna ligger mycket på individnivå och omfattas mest av färdighetsträning. Föräldrars och elevers delaktighet vid utformningen av åtgärdsprogrammen varierar. I intervjuerna framkommer att lärarna ser elevernas svårigheter som något utöver och utanför den ordinarie undervisningen. Lärarna förlägger åtgärderna under eget arbete i eller utanför klassrummet och ibland till och med innan eller efter skoltid. Konklusion: Formuleringarna av mål och åtgärder varierar beroende på vem som skriver. För att åtgärdsprogram ska fungera som verktyg för lärande måste pedagogerna först förstå begreppen i åtgärdsprogrammen. De måste även ha kunskaper om var eleverna befinner sig i sin utveckling och framförallt vart de är på väg så att mål och åtgärder blir kortsiktiga, konkreta och mätbara. Blanketternas utformning och ordval kan förvilla pedagogerna och bidra till feltolkningar. Detta är ett område som vi inte hittat någon forskning kring. Utifrån ett sociokulturellt perspektiv drar vi slutsatsen att fler åtgärder bör ligga på gruppnivå där dialogen blir ett viktigt redskap.Implementering: Specialpedagogens roll blir att föra en regelbunden dialog med lärarna ute på skolorna om åtgärdsprogrammens begrepp och vad som ska ingå i programmen. En annan uppgift för specialpedagogen blir att få lärarna att använda sig av gruppen och få arbetet med åtgärdsprogrammen integrerat i den ordinarie undervisningen. Får vi till detta blir åtgärdsprogrammen fungerande verktyg för lärande. Våra resultat stämmer med tidigare forskning kring formuleringen av innehållet i åtgärdsprogrammen. Implikationerna gäller därför både för oss specifikt men även i vidare mening

Spin Liquid State in an Organic Mott Insulator with Triangular Lattice

$^{1}$H NMR and static susceptibility measurements have been performed in an organic Mott insulator with nearly isotropic triangular lattice, $\kappa$-(BEDT-TTF)$_{2}$Cu$_{2}$(CN)$_{3}$, which is a model system of frustrated quantum spins. The static susceptibility is described by the spin $S$ = 1/2 antiferromagnetic triangular-lattice Heisenberg model with the exchange constant $J$ $\sim$ 250 K. Regardless of the large magnetic interactions, the $^{1}$H NMR spectra show no indication of long-range magnetic ordering down to 32 mK, which is four-orders of magnitude smaller than $J$. These results suggest that a quantum spin liquid state is realized in the close proximity of the superconducting state appearing under pressure.Comment: 4 pages, 4 figure

Summary of the NOW'98 Phenomenology Working Group

Summary of the Phenomenology Working Group at the Europhysics Neutrino Oscillation Workshop (NOW'98), 7-9 September 1998, Amsterdam.Comment: 66 page

Coupling of THz radiation with intervalence band transitions in microcavities

The strong coupling of THz radiation and material excitations can improve the quantum efficiency of THz emitters. In this paper, we investigate THz polaritons and antipolaritons based on valence band transitions, which allow TE coupling in a simple configuration. The approach can improve the quantum efficiency of THz based devices based on TE mode in the strong coupling regime of THz radiations and intervalence bands transitions in a GaAs/AlGaAs quantum wells. A Nonequilibrium Many Body Approach for the optical response beyond the Hartree-Fock approximation is used as input to the effective dielectric function formalism for the polariton/antipolariton problem. The energy dispersion relations in the THz range are obtained by adjusting the full numerical solutions to simple analytical expressions, which can be used for non specialists in a wide number of new structures and material systems. The combination of manybody and nonparabolicity at high densities leads to dramatic changes in the polariton spectra in a nonequilibrium configuration, which is only possible for intervalence band transitions