1,381 research outputs found

    JOINT MOMENTS DURING INSTEP KICKS IN FOOTBALL PLAYERS WITH AND WITHOUT PREVIOUS GROIN PAIN

    Get PDF
    This study examined how previous groin pain and approach angle affects stance leg and lumbar moments during instep kicks. Male football players with and without previous groin pain (n=11, and n=10) performed instep kicks from 45° and 60° angles while kinetic and kinematic data were recorded (1000Hz and 500Hz respectively). 3D stance leg net joint moments of the hip, knee, and ankle were calculated at peak swing knee flexion and ball contact and the sagittal L5/S1 joint moment was examined throughout the kick. Foot speed at ball contact indicated performance. Players with previous groin pain had lower moments during the kick compared to uninjured controls, but there was no difference in performance. This suggests that the players with previous groin pain utilized an aberrant kicking pattern that offloads certain joints but may cause compensations elsewhere in the kinetic chain

    Approximating Tverberg Points in Linear Time for Any Fixed Dimension

    Full text link
    Let P be a d-dimensional n-point set. A Tverberg-partition of P is a partition of P into r sets P_1, ..., P_r such that the convex hulls conv(P_1), ..., conv(P_r) have non-empty intersection. A point in the intersection of the conv(P_i)'s is called a Tverberg point of depth r for P. A classic result by Tverberg implies that there always exists a Tverberg partition of size n/(d+1), but it is not known how to find such a partition in polynomial time. Therefore, approximate solutions are of interest. We describe a deterministic algorithm that finds a Tverberg partition of size n/4(d+1)^3 in time d^{O(log d)} n. This means that for every fixed dimension we can compute an approximate Tverberg point (and hence also an approximate centerpoint) in linear time. Our algorithm is obtained by combining a novel lifting approach with a recent result by Miller and Sheehy (2010).Comment: 14 pages, 2 figures. A preliminary version appeared in SoCG 2012. This version removes an incorrect example at the end of Section 3.

    Two highly divergent alcohol dehydrogenases of melon exhibit fruit ripening-specific expression and distinct biochemical characteristics

    Get PDF
    Alcohol dehydrogenases (ADH) participate in the biosynthetic pathway of aroma volatiles in fruit by interconverting aldehydes to alcohols and providing substrates for the formation of esters. Two highly divergent ADH genes (15% identity at the amino acid level) of Cantaloupe Charentais melon (Cucumis melo var. Cantalupensis) have been isolated. Cm-ADH1 belongs to the medium-chain zinc-binding type of ADHs and is highly similar to all ADH genes expressed in fruit isolated so far. Cm-ADH2 belongs to the short-chain type of ADHs. The two encoded proteins are enzymatically active upon expression in yeast. Cm-ADH1 has strong preference for NAPDH as a co-factor, whereas Cm-ADH2 preferentially uses NADH. Both Cm-ADH proteins are much more active as reductases with Kms 10–20 times lower for the conversion of aldehydes to alcohols than for the dehydrogenation of alcohols to aldehydes. They both show strong preference for aliphatic aldehydes but Cm-ADH1 is capable of reducing branched aldehydes such as 3-methylbutyraldehyde, whereas Cm-ADH2 cannot. Both Cm-ADH genes are expressed specifically in fruit and up-regulated during ripening. Gene expression as well as total ADH activity are strongly inhibited in antisense ACC oxidase melons and in melon fruit treated with the ethylene antagonist 1-methylcyclopropene (1-MCP), indicating a positive regulation by ethylene. These data suggest that each of the Cm-ADH protein plays a specific role in the regulation of aroma biosynthesis in melon fruit

    Cross reactive cellular immune responses in chickens previously exposed to low pathogenic avian influenza

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Avian influenza (AI) infection in poultry can result in high morbidity and mortality, and negatively affect international trade. Because most AI vaccines used for poultry are inactivated, our knowledge of immunity against AI is based largely on humoral immune responses. In fact, little is known about cellular immunity following a primary AI infection in poultry, especially regarding cytotoxic T lymphocytes (CTL’s).</p> <p>Methods</p> <p>In these studies, major histocompatibility complex (MHC)-defined (B<sup>2</sup>/B<sup>2</sup>) chickens were infected with low pathogenic AI (LPAI) H9N2 and clinical signs of disease were monitored over a two weeks period. Splenic lymphocytes from infected and naïve birds were examined for cross reactivity against homologous and heterologous (H7N2) LPAI by ex vivo stimulation. Cellular immunity was determined by cytotoxic lysis of B<sup>2</sup>/B<sup>2</sup> infected lung target cells and proliferation of T cells following exposure to LPAI.</p> <p>Results</p> <p>Infection with H9N2 resulted in statistically significant weight loss compared to sham-infected birds. Splenic lymphocytes derived from H9N2-infected birds displayed lysis of both homologous (H9N2) and heterologous (H7N2) infected target cells, whereas lymphocytes obtained from sham-infected birds did not. T cell proliferation was determined to be highest when exposed to the homologous virus.</p> <p>Conclusions</p> <p>Taken together these data extend the findings that cellular immunity, including CTL’s, is cross reactive against heterologous isolates of AI and contribute to protection following infection.</p

    Polyfunctional T cell responses in children in early stages of chronic Trypanosoma cruzi infection contrast with monofunctional responses of long-term infected adults

    Get PDF
    Background: Adults with chronic Trypanosoma cruzi exhibit a poorly functional T cell compartment, characterized by monofunctional (IFN-γ-only secreting) parasite-specific T cells and increased levels of terminally differentiated T cells. It is possible that persistent infection and/or sustained exposure to parasites antigens may lead to a progressive loss of function of the immune T cells. Methodology/Principal Findings: To test this hypothesis, the quality and magnitude of T. cruzi-specific T cell responses were evaluated in T. cruzi-infected children and compared with long-term T. cruzi-infected adults with no evidence of heart failure. The phenotype of CD4+ T cells was also assessed in T. cruzi-infected children and uninfected controls. Simultaneous secretion of IFN-γ and IL-2 measured by ELISPOT assays in response to T. cruzi antigens was prevalent among T. cruzi-infected children. Flow cytometric analysis of co-expression profiles of CD4+ T cells with the ability to produce IFN-γ, TNF-α, or to express the co-stimulatory molecule CD154 in response to T. cruzi showed polyfunctional T cell responses in most T. cruzi-infected children. Monofunctional T cell responses and an absence of CD4+TNF-α+-secreting T cells were observed in T. cruzi-infected adults. A relatively high degree of activation and differentiation of CD4+ T cells was evident in T. cruzi-infected children. Conclusions/Significance: Our observations are compatible with our initial hypothesis that persistent T. cruzi infection promotes eventual exhaustion of immune system, which might contribute to disease progression in long-term infected subjects.Fil: Albareda, María Cecilia. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: de Rissio, Ana María. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; ArgentinaFil: Tomas, Gonzalo. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; ArgentinaFil: Serjan, Alicia. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Juan A. Fernández"; ArgentinaFil: Alvarez, María Gabriela. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Viotti, Rodolfo Jorge. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Fichera, Laura Edith. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Esteva, Mónica Inés. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; ArgentinaFil: Potente, Daniel Fernando. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Armenti, Alejandro. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Tarleton, Rick L.. University of Georgia; Estados UnidosFil: Laucella, Susana Adriana. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Anomalous Dimensions and Non-Gaussianity

    Full text link
    We analyze the signatures of inflationary models that are coupled to strongly interacting field theories, a basic class of multifield models also motivated by their role in providing dynamically small scales. Near the squeezed limit of the bispectrum, we find a simple scaling behavior determined by operator dimensions, which are constrained by the appropriate unitarity bounds. Specifically, we analyze two simple and calculable classes of examples: conformal field theories (CFTs), and large-N CFTs deformed by relevant time-dependent double-trace operators. Together these two classes of examples exhibit a wide range of scalings and shapes of the bispectrum, including nearly equilateral, orthogonal and local non-Gaussianity in different regimes. Along the way, we compare and contrast the shape and amplitude with previous results on weakly coupled fields coupled to inflation. This signature provides a precision test for strongly coupled sectors coupled to inflation via irrelevant operators suppressed by a high mass scale up to 1000 times the inflationary Hubble scale.Comment: 40 pages, 10 figure

    Exercise therapy in adults with serious mental illness: a systematic review and meta-analysis

    Get PDF
    Background: Individuals with serious mental illness are at a higher risk of physical ill health. Mortality rates are at least twice those of the general population with higher levels of cardiovascular disease, metabolic disease, diabetes, and respiratory illness. Although genetics may have a role in the physical health problems of these patients, lifestyle and environmental factors such as levels of smoking, obesity, poor diet, and low levels of physical activity also play a prominent part.&lt;p&gt;&lt;/p&gt; Objective: To conduct a systematic review and meta-analysis of randomised controlled trials comparing the effect of exercise interventions on individuals with serious mental illness.&lt;p&gt;&lt;/p&gt; Methods: Searches were made in Ovid MEDLINE, Embase, CINAHL, PsycINFO, Biological Abstracts on Ovid, and The Cochrane Library (January 2009, repeated January 2013) through to February 2013.&lt;p&gt;&lt;/p&gt; Results: Eight RCTs were identified in the systematic search. Six compared exercise versus usual care. One study assessed the effect of a cycling programme versus muscle strengthening and toning exercises. The final study compared the effect of adding specific exercise advice and motivational skills to a simple walking programme. Exercise programmes were noted by their heterogeneity in terms of the type of exercise intervention, setting, and outcome measures. The review found that exercise improved levels of exercise activity (n=13, standard mean difference [SMD] 1.81, CI 0.44 to 3.18, p = 0.01). No beneficial effect was found on negative (n = 84, SMD = -0.54, CI -1.79 to 0.71, p = 0.40) or positive symptoms of schizophrenia (n = 84, SMD = -1.66, CI -3.78 to 0.45, p = 0.12). No change was found on body mass index compared with usual care (n= 151, SMD = -0.24, CI -0.56 to 0.08, p = 0.14), or body weight (n = 77, SMD = 0.13, CI -0.32 to 0.58, p = 0.57). No beneficial effect was found on anxiety and depressive symptoms (n = 94, SMD = -0.26, CI -0.91 to 0.39, p = 0.43), or quality of life in respect of physical and mental domains. One RCT measured the effect of exercise on exercise intensity, attendance, and persistence at a programme. No significant effect was found on these measures.&lt;p&gt;&lt;/p&gt; Conclusions: This systematic review showed that exercise therapies can lead to a modest increase in levels of exercise activity but overall there was no noticeable change for symptoms of mental health, body mass index, and body weight.&lt;p&gt;&lt;/p&gt
    corecore