402 research outputs found

    Time-course changes associated with PA Lumbar Mobilizations on Lumbar and Hamstring Range of Motion:A Randomized Controlled Crossover Trial

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    Objective: We aimed to compare the post-intervention time-course changes in active knee extension (AKE) and active lumbar flexion (ALF) range of motion in response to unilateral posterior–anterior (UPA) mobilizations of the lumbar spine (L4/5 zygapophyseal). Methods: Twenty-four asymptomatic participants (maleness: 0.58, age [mean ± standard deviation]: 32 ± 8 years, body mass index 25.9 ± 2.6 kg m2) were recruited to a fully controlled crossover trial. Following either the intervention (L4/5 zygapophyseal mobilizations) or control, participants immediately performed the AKE and ALF tests, which were also performed at baseline. Subsequent tests were made at intervals of 5, 10, 15, 20, 25, 30, 45 and 60 min. Results: After adjustment for baseline (mean AKE: 37.2° from full extension, mean ALF: 14.37 cm), sex and age, UPA lumbar mobilizations had a most likely moderate effect on AKE (9.8° closer to full extension; ±1.9) and a likely moderate effect on ALF (1.34 cm; ±90% confidence limits 0.43). The magnitude of the AKE effect became most likely small 20-min posttreatment (5.3; ±1.7) and possibly small/possibly trivial 60-min posttreatment (2.1; ±1.4). For ALF, the magnitude of the effect became most likely small 15-min posttreatment (0.76; ±0.25), possibly small/possibly trivial 25-min posttreatment (0.38; ±0.18) and likely trivial 60-min posttreatment (0.26; ±1.8). Discussion: UPA lumbar mobilizations increased lumbar Range of Motion and hamstring extensibility by a moderate magnitude, with the effect reducing after 10–20-min posttreatment. Clinicians should consider these time-course changes when applying UPA lumbar mobilizations

    Artificial grass: a longitudinal study on ball roll and free pile height

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    Ball roll is seen as one of the first criterion which cause artificial grass pitches to fail performance standards. Previous research has demonstrated that the ball roll distance increased after a seven-year period. However, there is a lack of understanding in the mechanisms causing the ball roll distance to increase with time. During this study, the ball roll distance and free pile height were measured over a twelve-month period on an indoor pitch. The aim was to evaluate the early-life pitch performance and to determine if a correlation existed between ball roll distance and free pile height. The indoor environment protected the measurements from the confounding effects of wind and precipitation, providing a controlled environment in which to assess the effects of mechanical wear from player usage on both ball roll and free pile height. There was a general trend for the ball roll distance to increase and the free pile height to reduce with time. There was a strong, negative correlation (R= -0.967) between ball roll distance and free pile height. The ball roll distance increased above the FIFA 2* limit within the first twelve months of pitch life, however intervening drag brushing the surface was found to reduce ball roll distance to within the requirements, signifying the importance of regular drag brushing. Significant spatial variation (P<0.001) existed in ball roll and free pile height between high use and low use areas of the pitch. The study provides strong evidence on the effects of free pile height on the ball roll distance, indicating that pitch owners need effective maintenance to ensure the carpet pile remains upright to maintain ball roll distance to meet performance standards

    Understanding the effects of decompaction maintenance on the infill state and play performance of third-generation artificial grass pitches

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    Third generation artificial grass pitches have been observed to get harder over time. The maintenance technique of rubber infill decompaction is intended to help slow, or reverse, this process. At present, little is understood about either the science of the infill compaction process or the efficacy of decompaction maintenance. The objective of this study was to measure the changes in rubber infill net bulk density, force reduction (impact absorption) and vertical ball rebound under various levels of compactive effort in controlled laboratory-based testing. The assessments were repeated after the systems had been raked to simulate the decompaction maintenance techniques. These tests defined the limits of compaction (loose to maximally compacted) in terms of the change in rubber infill net bulk density, force reduction and vertical ball rebound. Site testing was also undertaken at four third generation pitches immediately pre and post decompaction, to determine the measurable effects in the less well controlled field environment. Rubber infill net bulk density was found to increase as compactive effort increased, resulting in increased hardness. Decompacting the surface was found to approximately fully reverse these effects. In comparison, the site measurements demonstrated similar but notably smaller magnitudes of change following the decompaction process suggesting that the field state pre and post decompaction did not reach the extremes obtained in the laboratory. The findings suggest that rubber infill net bulk density is an important parameter influencing the hardness of artificial grass and that decompactions can be an effective method to reverse compaction related hardness changes

    Artificial grass: a longitudinal study on ball roll and free pile height

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    Ball roll is seen as one of the first criterion which cause artificial grass pitches to fail performance standards. Previous research has demonstrated that the ball roll distance increased after a seven-year period. However, there is a lack of understanding in the mechanisms causing the ball roll distance to increase with time. During this study, the ball roll distance and free pile height were measured over a twelve-month period on an indoor pitch. The aim was to evaluate the early-life pitch performance and to determine if a correlation existed between ball roll distance and free pile height. The indoor environment protected the measurements from the confounding effects of wind and precipitation, providing a controlled environment in which to assess the effects of mechanical wear from player usage on both ball roll and free pile height. There was a general trend for the ball roll distance to increase and the free pile height to reduce with time. There was a strong, negative correlation (R= -0.967) between ball roll distance and free pile height. The ball roll distance increased above the FIFA 2* limit within the first twelve months of pitch life, however intervening drag brushing the surface was found to reduce ball roll distance to within the requirements, signifying the importance of regular drag brushing. Significant spatial variation (P<0.001) existed in ball roll and free pile height between high use and low use areas of the pitch. The study provides strong evidence on the effects of free pile height on the ball roll distance, indicating that pitch owners need effective maintenance to ensure the carpet pile remains upright to maintain ball roll distance to meet performance standards

    HLA Class I and KIR Genes Do Not Protect Against HIV Type 1 Infection in Highly Exposed Uninfected Individuals With Hemophilia A

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    A recent genome-wide association study (GWAS) involving patients with hemophilia A who were exposed to but uninfected with human immunodeficiency virus type 1 (HIV-1) did not reveal genetic variants associated with resistance to HIV-1 infection, beyond homozygosity for CCR5-Δ32. Since variation in HLA class I and KIR genes is not well interrogated by standard GWAS techniques, we tested whether these 2 loci were involved in protection from HIV-1 infection in the same hemophilia cohort, using controls from the general population. Our data indicate that HLA class I alleles, presence or absence of KIR genes, and functionally relevant combinations of the HLA/KIR genotypes are not involved in resistance to parenterally transmitted HIV-1 infectio

    HIV-1 Capture and Transmission by Dendritic Cells : The Role of Viral Glycolipids and the Cellular Receptor Siglec-1

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    Altres ajuts: Work in JMP group is supported by the Spanish AIDS network "Red Temática Cooperativa de Investigación en SIDA" (RD06/0006)Dendritic cells (DCs) are essential in order to combat invading viruses and trigger antiviral responses. Paradoxically, in the case of HIV-1, DCs might contribute to viral pathogenesis through trans -infection, a mechanism that promotes viral capture and transmission to target cells, especially after DC maturation. In this review, we highlight recent evidence identifying sialyllactose-containing gangliosides in the viral membrane and the cellular lectin Siglec-1 as critical determinants for HIV-1 capture and storage by mature DCs and for DC-mediated trans -infection of T cells. In contrast, DC-SIGN, long considered to be the main receptor for DC capture of HIV-1, plays a minor role in mature DC-mediated HIV-1 capture and trans -infection

    Estimating the Respective Contributions of Human and Viral Genetic Variation to HIV Control

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    We evaluated the fraction of variation in HIV-1 set point viral load attributable to viral or human genetic factors by using joint host/pathogen genetic data from 541 HIV infected individuals. We show that viral genetic diversity explains 29% of the variation in viral load while host factors explain 8.4%. Using a joint model including both host and viral effects, we estimate a total of 30% heritability, indicating that most of the host effects are reflected in viral sequence variation

    Disease-associated XMRV sequences are consistent with laboratory contamination.

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    BACKGROUND: Xenotropic murine leukaemia viruses (MLV-X) are endogenous gammaretroviruses that infect cells from many species, including humans. Xenotropic murine leukaemia virus-related virus (XMRV) is a retrovirus that has been the subject of intense debate since its detection in samples from humans with prostate cancer (PC) and chronic fatigue syndrome (CFS). Controversy has arisen from the failure of some studies to detect XMRV in PC or CFS patients and from inconsistent detection of XMRV in healthy controls. RESULTS: Here we demonstrate that Taqman PCR primers previously described as XMRV-specific can amplify common murine endogenous viral sequences from mouse suggesting that mouse DNA can contaminate patient samples and confound specific XMRV detection. To consider the provenance of XMRV we sequenced XMRV from the cell line 22Rv1, which is infected with an MLV-X that is indistinguishable from patient derived XMRV. Bayesian phylogenies clearly show that XMRV sequences reportedly derived from unlinked patients form a monophyletic clade with interspersed 22Rv1 clones (posterior probability >0.99). The cell line-derived sequences are ancestral to the patient-derived sequences (posterior probability >0.99). Furthermore, pol sequences apparently amplified from PC patient material (VP29 and VP184) are recombinants of XMRV and Moloney MLV (MoMLV) a virus with an envelope that lacks tropism for human cells. Considering the diversity of XMRV we show that the mean pairwise genetic distance among env and pol 22Rv1-derived sequences exceeds that of patient-associated sequences (Wilcoxon rank sum test: p = 0.005 and p < 0.001 for pol and env, respectively). Thus XMRV sequences acquire diversity in a cell line but not in patient samples. These observations are difficult to reconcile with the hypothesis that published XMRV sequences are related by a process of infectious transmission. CONCLUSIONS: We provide several independent lines of evidence that XMRV detected by sensitive PCR methods in patient samples is the likely result of PCR contamination with mouse DNA and that the described clones of XMRV arose from the tumour cell line 22Rv1, which was probably infected with XMRV during xenografting in mice. We propose that XMRV might not be a genuine human pathogen
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