65 research outputs found

    Varied patterns of catch-up in child growth: Evidence from Young Lives

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    The development of human capabilities for many disadvantaged children around the world depends on growth recovery ('catch-up growth'). Here we develop a novel framework that allows different types of catch-up growth to be classified and estimated. We distinguish between catch-up in the mean of a group toward that of a healthy reference population versus catch-up within the group. We show these different growth types can be tested in a unified setting using a latent growth framework. We apply the results to four developing countries, using longitudinal data on 7641 children collected over the period 2002-2013. The results show catch-up growth rates are generally modest but vary significantly between countries, and that local environmental factors are material to variation in child growth trajectories. The paper discusses the benefits of the new framework versus current methods, shows that the method is feasible, and suggests they call for intervention designs that are sensitive to community and country contexts

    Validity of new child-specific thoracic gas volume prediction equations for air-displacement plethysmography

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    BACKGROUND: To determine the validity of the recently developed child-specific thoracic gas volume (TGV) prediction equations for use in air-displacement plethysmography (ADP) in diverse pediatric populations. METHODS: Three distinct populations were studied: European American and African American children living in Birmingham, Alabama and European children living in Lisbon, Portugal. Each child completed a standard ADP testing protocol, including a measured TGV according to the manufactures software criteria. Measured TGV was compared to the predicted TGV from current adult-based ADP proprietary equations and to the recently developed child-specific TGV equations of Fields et al. Similarly, percent body fat, derived using the TGV prediction equations, was compared to percent body fat derived using measured TGV. RESULTS: Predicted TGV from adult-based equations was significantly different from measured TGV in girls from each of the three ethnic groups (P < 0.05), however child-specific TGV estimates did not significantly differ from measured TGV in any of the ethnic or gender groups. Percent body fat estimates using adult-derived and child-specific TGV estimates did not differ significantly from percent body fat measures using measured TGV in any of the groups. CONCLUSION: The child-specific TGV equations developed by Fields et al. provided a modest improvement over the adult-based TGV equations in an ethnically diverse group of children

    Does sport participation (including level of performance and previous injury) increase risk of osteoarthritis? A systematic review and meta-analysis

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    Background: To assess the relationship between sport and osteoarthritis, and specifically to determine whether previous participation, in terms of level (elite or non-elite), type of sport, intensity or previous injury were associated with osteoarthritis. Methods: This systematic review was developed using PRISMA guidelines. Databases were searched (to May 2016). Narrative review and meta-analysis (with risk ratio (RR) and 95% confidence intervals (CI)) approaches were undertaken where appropriate. Study quality was assessed using GRADE. Results: Forty-six studies were included. Narratively, 31 studies reported an increased risk of osteoarthritis, with 19 demonstrating an increased risk in elite athletes. There was an increased risk after sports exposure (irrespective of type) (RR:1.37; 95% CI:1.14, 1.64; 21 studies). It remained uncertain whether there was a difference in risk of osteoarthritis between elite and non-elite athletes (RR:1.37; 95% CI:0.84, 2.22; 17 studies). Risk was higher in soccer (RR:1.42; 95% CI:1.14, 1.77; 15 studies), but lower runners (RR:0.86; 95% CI:0.53, 1.41; 12 studies). Nine studies showed an association with the intensity of sport undertaken and osteoarthritis. Five studies demonstrated a higher prevalence of osteoarthritis following meniscectomies and anterior cruciate ligament tears. Overall the evidence was of GRADE 'very low' quality. Conclusions: There was very low quality evidence to support an increased relationship between sports participation and osteoarthritis in elite participants. It is unclear whether there is a difference in risk between elite and non-elite participants with further prospective studies needed to evaluate this. Pooled findings suggested significant injuries were associated with OA in soccer players

    Minimizing the source of nociception and its concurrent effect on sensory hypersensitivity: An exploratory study in chronic whiplash patients

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    Abstract. Background. The cervical zygapophyseal joints may be a primary source of pain in up to 60% of individuals with chronic whiplash associated disorders (WAD) and may be a contributing factor for peripheral and centrally mediated pain (sensory hypersensitivity). Sensory hypersensitivity has been associated with a poor prognosis. The purpose of the study was to determine if there is a change in measures indicative of sensory hypersensitivity in patients with chronic WAD grade II following a medial branch block (MBB) procedure in the cervical spine. Methods. Measures of sensory hypersensitivity were taken via quantitative sensory testing (QST) consisting of pressure pain thresholds (PPT's) and cold pain thresholds (CPT's). In patients with chronic WAD (n = 18), the measures were taken at three sites bilaterally, pre- and post- MBB. Reduced pain thresholds at remote sites have been considered an indicator of central hypersensitivity. A healthy age and gender matched comparison group (n = 18) was measured at baseline. An independent t-test was applied to determine if there were any significant differences between the WAD and normative comparison groups at baseline with respect to cold pain and pressure pain thresholds. A dependent t-test was used to determine whether there were any significant differences between the pre and post intervention cold pain and pressure pain thresholds in the patients with chronic WAD. Results. At baseline, PPT's were decreased at all three sites in the WAD group (p < 0.001). Cold pain thresholds were increased in the cervical spine in the WAD group (p < 0.001). Post-MBB, the WAD group showed significant increases in PPT's at all sites (p < 0.05), and significant decreases in CPT's at the cervical spine (p < 0.001). Conclusions. The patients with chronic WAD showed evidence of widespread sensory hypersensitivity to mechanical and thermal stimuli. The WAD group revealed decreased sensory hypersensitivity following a decrease in their primary source of pain stemming from the cervical zygapophyseal joints

    Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

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    Lawson criterion for ignition exceeded in an inertial fusion experiment

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    For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

    Acupuncture for chronic knee pain: a randomized clinical trial.

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    IMPORTANCE: There is debate about benefits of acupuncture for knee pain. OBJECTIVE: To determine the efficacy of laser and needle acupuncture for chronic knee pain. DESIGN, SETTING, AND PARTICIPANTS: Zelen-design clinical trial (randomization occurred before informed consent), in Victoria, Australia (February 2010-December 2012). Community volunteers (282 patients aged ≥50 years with chronic knee pain) were treated by family physician acupuncturists. INTERVENTIONS: No acupuncture (control group, n = 71) and needle (n = 70), laser (n = 71), and sham laser (n = 70) acupuncture. Treatments were delivered for 12 weeks. Participants and acupuncturists were blinded to laser and sham laser acupuncture. Control participants were unaware of the trial. MAIN OUTCOMES AND MEASURES: Primary outcomes were average knee pain (numeric rating scale, 0 [no pain] to 10 [worst pain possible]; minimal clinically important difference [MCID], 1.8 units) and physical function (Western Ontario and McMaster Universities Osteoarthritis Index, 0 [no difficulty] to 68 [extreme difficulty]; MCID, 6 units) at 12 weeks. Secondary outcomes included other pain and function measures, quality of life, global change, and 1-year follow-up. Analyses were by intention-to-treat using multiple imputation for missing outcome data. RESULTS: At 12 weeks and 1 year, 26 (9%) and 50 (18%) participants were lost to follow-up, respectively. Analyses showed neither needle nor laser acupuncture significantly improved pain (mean difference; -0.4 units; 95% CI, -1.2 to 0.4, and -0.1; 95% CI, -0.9 to 0.7, respectively) or function (-1.7; 95% CI, -6.1 to 2.6, and 0.5; 95% CI, -3.4 to 4.4, respectively) compared with sham at 12 weeks. Compared with control, needle and laser acupuncture resulted in modest improvements in pain (-1.1; 95% CI, -1.8 to -0.4, and -0.8; 95% CI, -1.5 to -0.1, respectively) at 12 weeks, but not at 1 year. Needle acupuncture resulted in modest improvement in function compared with control at 12 weeks (-3.9; 95% CI, -7.7 to -0.2) but was not significantly different from sham (-1.7; 95% CI, -6.1 to 2.6) and was not maintained at 1 year. There were no differences for most secondary outcomes and no serious adverse events. CONCLUSIONS AND RELEVANCE: In patients older than 50 years with moderate or severe chronic knee pain, neither laser nor needle acupuncture conferred benefit over sham for pain or function. Our findings do not support acupuncture for these patients. TRIAL REGISTRATION: anzctr.org.au Identifier: ACTRN12609001001280
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