4,817 research outputs found

    Evaluation of the cytotoxic and genotoxic potential of Khat (Catha edulis Forsk) extracts on human T lymphoblastoid cell line

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    This paper reports on an investigation of the cytotoxic and genotoxic potential of khat extract using a human T lymphoblastoid cell line (CEM). Exponentially growing CEM cells were cultured for 12 h in the presence of khat extract (0-2000 μg ml-1). Statistically significant, dose-dependent increases in; CEM cell death at dose (> 400 μg ml-1), in DNA damage at dose (>200 μg ml-1) and in micronuclei frequency, at dose (>200 μg ml-1) were observed. The genetic damage effects of khat extract on human cell line observed in this study could serve as a major contribution towards the understanding and creating of awareness of an increased risk of cancer amongst long-term khat consumers

    How Do I Fit through That Gap? Navigation through Apertures in Adults with and without Developmental Coordination Disorder

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    During everyday life we move around busy environments and encounter a range of obstacles, such as a narrow aperture forcing us to rotate our shoulders in order to pass through. In typically developing individuals the decision to rotate the shoulders is body scaled and this movement adaptation is temporally and spatially tailored to the size of the aperture. This is done effortlessly although it actually involves many complex skills. For individuals with Developmental Coordination Disorder (DCD) moving in a busy environment and negotiating obstacles presents a real challenge which can negatively impact on safety and participation in motor activities in everyday life. However, we have a limited understanding of the nature of the difficulties encountered. Therefore, this current study considered how adults with DCD make action judgements and movement adaptations while navigating apertures. Fifteen adults with DCD and 15 typically developing (TD) controls passed through a series of aperture sizes which were scaled to body size (0.9-2.1 times shoulder width). Spatial and temporal characteristics of movement were collected over the approach phase and while crossing the aperture. The decision to rotate the shoulders was not scaled in the same way for the two groups, with the adults with DCD showing a greater propensity to turn for larger apertures compared to the TD adults when body size alone was accounted for. However, when accounting for degree of lateral trunk movement and variability on the approach, we no longer saw differences between the two groups. In terms of the movement adaptations, the adults with DCD approached an aperture differently when a shoulder rotation was required and then adapted their movement sooner compared to their typical peers. These results point towards an adaptive strategy in adults with DCD which allows them to account for their movement difficulties and avoid collision

    When an object appears unexpectedly: object circumvention in adults

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    Obstacles often appear unexpectedly in our pathway and these require us to make immediate adjustments. Despite how regularly we encounter such situations only few studies have considered how we adjust to unexpected obstacles in the pathway which require us to walk around them. The current study considered how adults adjust to the possibility of an obstacle appearing and then also how foot placement is adjusted to circumvent an obstacle. Fifteen healthy adults walked down an 11m walkway, initially they were told this was a clear pathway and nothing in the environment would change (no gate), they then performed a series of trials in which a gate may (gate close) or may not (gate open) partially obstruct their pathway. We found that medio-lateral trunk velocity and acceleration was significantly increased when there was the possibility of an obstacle but before the obstacle appeared. This demonstrates an adaptive walking strategy which seems to enable healthy young adults to successfully circumvent obstacles. We also categorised foot placement adjustments and found that adults favoured making shorter and wider steps away from the obstacle. We suggest this combination of adjustments allows participants to maintain stability whilst successfully circumventing the obstacle

    Relationship of serum adiponectin and resistin to glucose intolerance and fat topography in south-Asians

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    Objectives South-Asians have lower adiponectin levels compared to Caucasians. It was not clear however, if this intrinsic feature is related to aspects of glucose metabolism. This study aims to determine the relationship between body fat distribution and adipocytokine in South-Asian subjects by measuring serum adipocytokines, adiposity, insulinemia, and glucose tolerance levels. Methods In this cross-sectional study, 150 South-Asians (80 males, 70 females) were included, 60 had NGT (Control group, Age 51.33 ± 11.5, BMI 27 ± 2.3), 60 had IGT (Age 57.7 ± 12.5, BMI 27.2 ± 2.7), 30 had type 2 DM (Age 49.5 ± 10.9, BMI 28 ± 1.7). Measures of adiposity, adipocytokines and other metabolic parameters were determined. Parameters were measured using the following: a) Plasma glucose by glucose oxidase method b) CRP by immunoturbidimetric method (Roche/Hitachi analyser) c) insulin by Medgenix INS-ELISA immunoenzymetric assay by Biosource (Belgium) d) Leptin, Adiponectin by radioimmunoassay kits by Linco Research (St. Charles MO) e) Resistin by immunoassay kits by Phoenix Pharmaceuticals INC (530 Harbor Boulevard, Belmont CA 94002, USA). Results Adiponectin concentrations were highest in NGT, decreased in IGT and lowest in DMT2, (both p < 0.01). Leptin was significantly higher in DMT2 than IGT and NGT p = 0.02 and 0.04 respectively. There was a significant positive relationships between log adiponectin and 2-hr insulin values, p = 0.028 and history of hypertensions and a ischemic heart disease p = 0.008 with R = 0.65. There was a significant inverse correlation between log adiponectin and resistin, p < 0.01. Conclusion Resistin levels had an inverse correlation with adiponectin levels, indicating an inverse relationship between pro-inflammatory cytokines and adiponectin. Adiponectin levels were related to glucose tolerance

    Which Swiitch Is The Switch, Miss, For Ipswich

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    https://digitalcommons.library.umaine.edu/mmb-vp/5479/thumbnail.jp

    The feasibility of using sonoelastography to identify the effect of joint hypermobility syndrome on elasticity of gastrocnemius muscle

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    Background: Joint hypermobility syndrome (JHS) is a heritable connective tissue disorder in which multiple synovial joints demonstrate a painful and extraordinary range of motion. Genetically there are abnormal changes in the connective tissue matrix in people with JHS, and that may alter the viscoelasticity of their muscular tissue. Sonoelastography (SEG) is a new technology in musculoskeletal practice for assessing tissue elasticity. This study aimed to determine the feasibility of using SEG to distinguish between those with and without a diagnosis of JHS. Gastrocnemius muscle (GM) elasticity was examined, as it is essential for balance and walking.Methods: Twenty participants were examined in a cross-sectional feasibility study: 10 participants diagnosed with JHS and 10 age- and gender-matched healthy controls. The dominant GM was scanned three times using SEG. The colours of the SEG images indicate soft (red), intermediate (green) and hard (blue) tissues. ImageJ software was used to analyse the images by identifying the mean percentage of pixels of each colour.Results: For the JHS group, nine females and one male were examined, with a mean age of 38.9 years (S.D. 15.53). Similarly, for the non-JHS group, nine females and one male were examined, with a mean age of 38.9 years (S.D. 12.37). The groups were comparable in terms of age, gender and BMI (P = 1.00, 1.00, and 0.77, respectively).The JHS group had a significantly higher percentage of blue (hard tissue) pixels when compared with the control group (P = 0.035). No significant differences were found in the mean percentage of green (intermediate) and red (soft) pixels (P = 0.55 and P = 0.051, respectively).SEG required a reasonable amount of training for clinicians with sufficient background in musculoskeletal anatomy, 4 h of observation and practical training. The examination was completed in < 5 min, so it may be reasonable for use in clinical practice, and it was well tolerated by patients. The SEG image was analysed in < 5 minutes.Conclusion: The results indicate that the GM in people with JHS had more areas of hard tissue when compared with the control group, contradicting the expected results. However, GM hyperactivity has been identified during walking in people with JHS, and increased muscle tone might therefore explain the findings. The findings need to be verified in a much larger future study. The SEG seems a feasible tool for quantifying muscular tissue elasticity in JHS

    Bounds on the lightest Higgs boson mass with three and four fermion generations

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    We present lower bounds on the Higgs boson mass in the Standard Model with three and four fermion generations SM(3,4), as well as upper bounds on the lightest Higgs boson mass in the minimal supersymmetric extension of the SM with three and four generations MSSM(3,4). Our analysis utilizes the SM(3,4) renormalization-group-improved one-loop effective potential of the Higgs boson to find the upper bounds on the Higgs mass in the MSSM(3,4) while the lower bounds in the SM(3,4) are derived from considerations of vacuum stability. All the bounds increase as the degenerate fourth generation mass increases, providing more room in theory space that respects the increasing experimental lower limit of the Higgs mass.Comment: 24 pages, 10 figures, Some additional discussion added. Final version to be published in International Journal of Modern Physics

    Proton Structure Functions from Chiral Dynamics and QCD Constraints

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    The spin fractions and deep inelastic structure functions of the proton are analyzed using chiral field theory involving Goldstone bosons. A detailed comparison with recent chiral models sheds light on their successful description of the spin fractions of the proton as being due to neglecting helicity non-flip chiral transitions. This approximation is valid for zero mass quarks but not for constituent quarks. Since the chiral spin fraction models with the pure spin-flip approximation reproduce the measured spin fractions of the proton, axialvector constituent-quark-Goldstone boson coupling is found to be inconsistent with the proton spin data. Initial quark valence distributions are then constructed using quark counting constraints at Bjorken x→1x \to 1 and Regge behavior at x→0x \to 0. Sea quark distributions predicted by chiral field theory on this basis have correct order of magnitude and shape. The spin fractions agree with the data.Comment: 30 pages, 2 tables, 10 figure-ps files, LaTex. Accepted by Int. J. Mod. Phys. A. More details added on polarized chiral splitting function

    Imperfect transparency and camouflage in glass frogs

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