The epidemiology and prevention of injuries in contact flag football

Sport wordt beschouwd als een essentieel onderdeel van een actieve en gezonde levensstijl, waardoor het risico tot het oplopen van verschillende ziekten vermindert en bijdraagt tot een beter psychisch en fysisch welbevinden. De gunstige effecten van sporten moeten afgewogen worden tegen het risico op letsels, die deels onvermijdelijk zijn. Hoewel de noodzaak aan interventie studies in de ‘realworld’ contex van sportbeoefening duidelijk aanwezig is, is er tot op heden heel weinig onderzoek gedaan op dit belangrijke onderzoeksdomein. Het oorspronkelijke onderzoek binnen dit doctoraat is begonnen in de loop van het contact “flag football” seizoen in Israel, in 2005. Hoewel contact flag football een niet-contact sport is, en de daardoor opgelopen blessures beschouwd kunnen worden als "licht", zijn de kosten van behandeling van deze blessures hoog. Dit onderzoek toonde aan dat 88% van de blessures opgelopen werden in 5 anatomische gebieden: handen, gezicht/hoofd, knieen, enkels en schouders. Bijna 40% van alle hand/vingerverwondingen (die bestaan uit 30% van alle blessures) waren een direct gevolg van vingers die ingeklemd bleven in de broekzakken van de tegenstanders. Als resultaat van de epidemiologische gegevens welke geextrapoleerd zijn uit deze studie, is een blessure preventieve pilot studie opgezet over een seizoen (experimentele cohort) met als doel een aanzienlijke vermindering te verkrijgen van de incidentie en de ernst van sport gerelateerde letsels. Vier interventies werden uitgevoerd: verbod van in de broekzakken te graaien (no pocket-rule), het dragen van enkel braces, en het verschaffen van een informatiebrochure over blessure behandeling. In deze studie werd een daling van het aantal letsels vastgesteld in alle lichaamsdelen, maar statistische significantie werd alleen geconstateerd in het aantal vinger/duim letsels (p<0,05) Op basis van de ervaringen van de pilot studie werd een 2-seizoens prospectieve blessure-preventieve cohort studie (hoofdstuk 4) opgezet. Deze studie toonde een vermindering van 88% van het totale aantal blessures aan. Een statistisch significante vermindering van hand/pols verwondingen werd vastgesteld (P<0,001). Ook was er een significante vermindering van de ernst van milde tot matige verwondingen(p<0,05). De "no pocket-rule” en het verplichte gebruik van mondbeschermers is op basis van de studieresultaten uitgegroeid tot een definitieve regel in de AFI-competitie. Met behulp van de verkregen resultaten zullen aanbevelingen worden gedaan aan de International Federation of Flag Football (IFAF). Aanbevelingen zijn gedaan aan de IFAF (hoofdstuk 6) waaronder het wijzigen van de regels met betrekking op blokkeren (in contact flag football), mondbeschermers verplicht te voorzien van duidelijke kleur, en de strikte toepassing van de 'no pocket-rule". Sterk aanbevolen werd het dragen van comfortabel zittende beschermende enkelbraces en zachte hooofddeksels. Ook het veranderen van de regels met betrekking tot blokkeren, zullen leiden tot een verdere reductie van frequentie en ernst van blessures in deze snel groeiende internationale sport, waardoor contact flag football veiliger voor alle betrokkenen wordt

The prevention of injuries in contact flag football

American flag football is a non-tackle, contact sport with many moderate to severe contact-type injuries reported. A previous prospective injury surveillance study by the authors revealed a high incidence of injuries to the fingers, face, knee, shoulder and ankle. The objectives of the study were to conduct a pilot-prospective injury prevention study in an attempt to significantly reduce the incidence and the severity of injuries as compared to a historical cohort, as well as to provide recommendations for a future prospective injury prevention study. A prospective injury prevention study was conducted involving 724 amateur male (mean age: 20.0 +/- A 3.1 years) and 114 female (mean age: 21.2 +/- A 7.2 years) players. Four prevention measures were implemented: the no-pocket rule, self-fitting mouth guards, ankle braces (for those players with recurrent ankle sprains) and an injury treatment information brochure. An injury surveillance questionnaire was administered to record all time-loss injuries sustained in game sessions. There was a statistically significant reduction in the number of injured players, the number of finger/hand injuries, the incidence rate and the incidence proportion between the two cohorts (p < 0.05). This one-season pilot prevention study has provided preliminary evidence that finger/hand injuries can be significantly reduced in flag football. Prevention strategies for a longer, prospective, randomised-controlled injury prevention study should include the strict enforcement of the no-pocket rule, appropriate head gear, the use of comfortable-fitting ankle braces and mouth guards, and changing the blocking rules of the game

Quark Solitons from Effective Action of QCD

We derive an effective low energy action for QCD in 4 dimensions. The low energy dynamics is described by chiral fields transforming non-trivially under both color and flavor. We use the method of anomaly integration from the QCD action. The solitons of the theory have the quantum numbers of quarks. They are expected to be the constituent quarks of hadrons. In two dimensions our result is exact, namely the bosonic gauged action of WZW.Comment: 19 pages (phyzzx macropackage) WIS-93/110/Nov-PH, TAUP 2117-93. Some sign changes, one sentence added following eq(3.9), and one ref. [23] adde

Empowerment for Continuous Agent-Environment Systems

This paper develops generalizations of empowerment to continuous states. Empowerment is a recently introduced information-theoretic quantity motivated by hypotheses about the efficiency of the sensorimotor loop in biological organisms, but also from considerations stemming from curiosity-driven learning. Empowemerment measures, for agent-environment systems with stochastic transitions, how much influence an agent has on its environment, but only that influence that can be sensed by the agent sensors. It is an information-theoretic generalization of joint controllability (influence on environment) and observability (measurement by sensors) of the environment by the agent, both controllability and observability being usually defined in control theory as the dimensionality of the control/observation spaces. Earlier work has shown that empowerment has various interesting and relevant properties, e.g., it allows us to identify salient states using only the dynamics, and it can act as intrinsic reward without requiring an external reward. However, in this previous work empowerment was limited to the case of small-scale and discrete domains and furthermore state transition probabilities were assumed to be known. The goal of this paper is to extend empowerment to the significantly more important and relevant case of continuous vector-valued state spaces and initially unknown state transition probabilities. The continuous state space is addressed by Monte-Carlo approximation; the unknown transitions are addressed by model learning and prediction for which we apply Gaussian processes regression with iterated forecasting. In a number of well-known continuous control tasks we examine the dynamics induced by empowerment and include an application to exploration and online model learning

Junior Recital: Connor Osburn, horn

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Performance. Mr. Osburn studies horn with Tom Witte.https://digitalcommons.kennesaw.edu/musicprograms/1306/thumbnail.jp

Strange and singlet form factors of the nucleon: Predictions for G0, A4, and HAPPEX-II experiments

We investigate the strange and flavor-singlet electric and magnetic form factors of the nucleon within the framework of the SU(3) chiral quark-soliton model. Isospin symmetry is assumed and the symmetry-conserving SU(3) quantization is employed, rotational and strange quark mass corrections being included. For the experiments G0, A4, and HAPPEX-II we predict the quantities $G^{0}_E + \beta G^{0}_M$ and $G^{\rm s}_E + \beta G^{\rm s}_M$. The dependence of the results on the parameters of the model and the treatment of the Yukawa asymptotic behavior of the soliton are investigated.Comment: 16 pages, 3 figures, Final version for publication in Eur. Phys. J.

The Constitutent Quark as a Topological Soliton

Recently it was proposed that the constituent quark is a topological soliton. I investigate this soliton, calculating its mass, radius, magnetic moment, color magnetic moment, and spin structure function. Within the approximations used, the magnetic moments and spin structure function cannot simultaneously be made to agree with the constituent quark model. Some discussion of what to expect from better approximations is included.Comment: 21 pages, LBL-3510

A heterobivalent ligand inhibits mast cell degranulation via selective inhibition of allergen-IgE interactions in vivo

Current treatments for allergies include epinephrine and antihistamines, which treat the symptoms after an allergic response has taken place; steroids, which result in local and systemic immune suppression; and IgE-depleting therapies, which can be used only for a narrow range of clinical IgE titers. The limitations of current treatments motivated the design of a heterobivalent inhibitor (HBI) of IgE-mediated allergic responses that selectively inhibits allergen-IgE interactions, thereby preventing IgE clustering and mast cell degranulation. The HBI was designed to simultaneously target the allergen binding site and the adjacent conserved nucleotide binding site (NBS) found on the Fab of IgE Abs. The bivalent targeting was accomplished by linking a hapten to an NBS ligand with an ethylene glycol linker. The hapten moiety of HBI enables selective targeting of a specific IgE, whereas the NBS ligand enhances avidity for the IgE. Simultaneous bivalent binding to both sites provided HBI with 120-fold enhancement in avidity for the target IgE compared with the monovalent hapten. The increased avidity for IgE made HBI a potent inhibitor of mast cell degranulation in the rat basophilic leukemia mast cell model, in the passive cutaneous anaphylaxis mouse model of allergy, and in mice sensitized to the model allergen. In addition, HBI did not have any observable systemic toxic effects even at elevated doses. Taken together, these results establish the HBI design as a broadly applicable platform with therapeutic potential for the targeted and selective inhibition of IgE-mediated allergic responses, including food, environmental, and drug allergies

Strange vector form factors of the nucleon in the SU(3) chiral quark-soliton model with the proper kaonic cloud

The strange vector form factors are evaluated in the range between $Q^2=0$ and Q^2=1\ \mbox{GeV}^2 in the framework of the SU(3) chiral quark-soliton model (or semi-bosonized SU(3) Nambu-Jona-Lasinio model). The rotational $1/N_c$ and $m_s$ corrections are taken into account up to linear order. Taking care of a proper Yukawa-tail of the kaonic cloud, we get \langle r^{2}\rangle^{\rm Sachs}_{s}=-0.095\; \mbox{fm}^2 and $\mu_s = -0.68\;\mu_N$. The results are compared with several different models.Comment: 27 pages with 8 figures. RevTeX and epsfig.sty are used. Submitted to Nucl. Phys.