726 research outputs found

    Dynamic structure factor of the Ising model with purely relaxational dynamics

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    We compute the dynamic structure factor for the Ising model with a purely relaxational dynamics (model A). We perform a perturbative calculation in the ϵ\epsilon expansion, at two loops in the high-temperature phase and at one loop in the temperature magnetic-field plane, and a Monte Carlo simulation in the high-temperature phase. We find that the dynamic structure factor is very well approximated by its mean-field Gaussian form up to moderately large values of the frequency ω\omega and momentum kk. In the region we can investigate, kξ5k\xi \lesssim 5, ωτ10\omega \tau \lesssim 10, where ξ\xi is the correlation length and τ\tau the zero-momentum autocorrelation time, deviations are at most of a few percent.Comment: 21 pages, 3 figure

    Heavy metal contamination in recorded and unrecorded spirits. Should we worry?

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    Heavy metals can be released into all alcoholic beverages during production and storage. However, there is at least a theoretical risk that they could be present in higher, and potentially toxic, concentrations in those produced in the household and small-scale stills common in Central and Eastern Europe, which lack quality control and whose products are unrecorded by authorities. Yet, so far, few studies comparing concentrations of heavy metals in recorded and unrecorded spirits have been published. In this study we ask whether there is any difference between heavy metal concentrations in recorded and unrecorded spirits and, thus, the related health risk. The levels of heavy metals were determined in recorded (n = 97) and unrecorded (n = 100) spirits using inductively coupled plasma optical emission spectrometric analysis and applied to population-based risk assessments, considering average, regular and chronic heavy drinkers. Concentrations of Cu, Zn, and Sn were significantly higher in unrecorded spirits than those in their recorded counterparts and recorded spirits contained significantly higher levels of Fe, Mn, and Ni than unrecorded spirits. Combined exposure to heavy metals posed a potential health risk in chronic heavy drinkers consuming recorded spirits. However, when compared to the health risk arising from drinking large volumes of ethanol, the risk is negligible. Consequently, there are no grounds to worry about the adverse effects of heavy metals from spirits

    Brief psychosocial education, not core stabilization, reduced incidence of low back pain: results from the Prevention of Low Back Pain in the Military (POLM) cluster randomized trial

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    <p>Abstract</p> <p>Background</p> <p>Effective strategies for the primary prevention of low back pain (LBP) remain elusive with few large-scale clinical trials investigating exercise and education approaches. The purpose of this trial was to determine whether core stabilization alone or in combination with psychosocial education prevented incidence of low back pain in comparison to traditional lumbar exercise.</p> <p>Methods</p> <p>The Prevention of Low Back Pain in the Military study was a cluster randomized clinical study with four intervention arms and a two-year follow-up. Participants were recruited from a military training setting from 2007 to 2008. Soldiers in 20 consecutive companies were considered for eligibility (n = 7,616). Of those, 1,741 were ineligible and 1,550 were eligible but refused participation. For the 4,325 Soldiers enrolled with no previous history of LBP average age was 22.0 years (SD = 4.2) and there were 3,082 males (71.3%). Companies were randomly assigned to receive traditional lumbar exercise, traditional lumbar exercise with psychosocial education, core stabilization exercise, or core stabilization with psychosocial education, The psychosocial education session occurred during one session and the exercise programs were done daily for 5 minutes over 12 weeks. The primary outcome for this trial was incidence of low back pain resulting in the seeking of health care.</p> <p>Results</p> <p>There were no adverse events reported. Evaluable patient analysis (4,147/4,325 provided data) indicated no differences in low back incidence resulting in the seeking of health care between those receiving the traditional exercise and core stabilization exercise programs. However, brief psychosocial education prevented low back pain episodes regardless of the assigned exercise approach, resulting in a 3.3% (95% CI: 1.1 to 5.5%) decrease over two years (numbers needed to treat (NNT) = 30.3, 95% CI = 18.2 to 90.9).</p> <p>Conclusions</p> <p>Core stabilization has been advocated as preventative, but offered no such benefit when compared to traditional lumbar exercise in this trial. Instead, a brief psychosocial education program that reduced fear and threat of low back pain decreased incidence of low back pain resulting in the seeking of health care. Since this trial was conducted in a military setting, future studies are necessary to determine if these findings can be translated into civilian populations.</p> <p>Trial Registration</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT00373009">NCT00373009</a> at ClinicalTrials.gov - <url>http://clinicaltrials.gov/</url></p

    The role of γδ T cells in airway epithelial injury and bronchial responsiveness after chlorine gas exposure in mice

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    BACKGROUND: Acute exposure to chlorine (Cl(2)) gas causes epithelial injury and airway dysfunction. γδ T cells are present in the mucosal surface of the airways and may contribute to the injury/repair response of the epithelium. METHODS: C57Bl/6J (wild type) and TCR-δ(-/- )mice exposed to Cl(2 )(400 ppm) for 5 minutes underwent measurements of airway responses to i.v. methacholine (MCh) at 1, 3, and 5 days after exposure. Bronchoalveolar lavage was performed to determine epithelial and leukocyte counts, and protein content. Tissue repair was assessed by proliferating cell nuclear antigen (PCNA) immunoreactivity and by expression of keratinocyte growth factor (KGF) mRNA by real-time PCR. RESULTS: Wild type mice developed a greater degree of airway hyperresponsiveness to MCh at 1 day post exposure to Cl(2 )compared with TCR-δ(-/- )mice. Epithelial cell counts in BAL after Cl(2 )exposure were greater in TCR-δ(-/- )mice, but macrophages showed a later peak and granulocyte numbers were lower in TCR-δ(-/- )than in wild type mice. Both groups had increased levels of total protein content in BAL after Cl(2 )exposure that resolved after 3 and 5 days, respectively. Epithelial proliferating cell nuclear antigen staining was increased at 1 and 3 days post exposure and was similar in the two groups. KGF mRNA was constitutively expressed in both groups and did not increase significantly after Cl(2 )but expression was lower in TCR-δ(-/- )mice. CONCLUSION: The severity of airway epithelial injury after Cl(2 )is greater in TCR-δ(-/- )mice but the inflammatory response and the change in airway responsiveness to methacholine are reduced. The rates of epithelial regeneration are comparable in both groups

    Can we monitor heart attack in the troponin era: evidence from a population-based cohort study

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    <p>Abstract</p> <p>Background</p> <p>Troponins (highly sensitive biomarkers of myocardial damage) increase counts of myocardial infarction (MI) in clinical practice, but their impact on trends in admission rates for MI in National statistics is uncertain.</p> <p>Methods</p> <p>Cases coded as MI or other cardiac diagnoses in the Hospital Morbidity Data Collection (MI-HMDC) in Western Australia in 1998 and 2003 were classified using revised criteria for MI developed by an International panel convened by the American Heart Association (AHA criteria) using information on symptoms, ECGs and cardiac biomarkers abstracted from samples of medical notes. Age-sex standardized rates of MI-HMDC were compared with rates of MI based on AHA criteria including troponins (MI-AHA) or traditional biomarkers only (MI-AHAck).</p> <p>Results</p> <p>Between 1998 and 2003, rates of MI-HMDC decreased by 3.5% whereas rates of MI-AHA increased by 17%, a difference largely due to increased false-negative cases in the HMDC associated with marked increased use of troponin tests in cardiac admissions generally, and progressively lower test thresholds. In contrast, rates of MI-AHA<sub>ck </sub>declined by 18%.</p> <p>Conclusions</p> <p>Increasing misclassification of MI-AHA by the HMDC may be due to reluctance by clinicians to diagnose MI based on relatively small increases in troponin levels. These influences are likely to continue. Monitoring MI using AHA criteria will require calibration of commercially available troponin tests and agreement on lower diagnostic thresholds for epidemiological studies. Declining rates of MI-AHA<sub>ck </sub>are consistent with long-standing trends in MI in Western Australia, suggesting that neither MI-HMDC nor MI-AHA reflect the true underlying population trends in MI.</p

    Dimethylthiourea protects against chlorine induced changes in airway function in a murine model of irritant induced asthma

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    <p>Abstract</p> <p>Background</p> <p>Exposure to chlorine (Cl<sub>2</sub>) causes airway injury, characterized by oxidative damage, an influx of inflammatory cells and airway hyperresponsiveness. We hypothesized that Cl<sub>2</sub>-induced airway injury may be attenuated by antioxidant treatment, even after the initial injury.</p> <p>Methods</p> <p>Balb/C mice were exposed to Cl<sub>2 </sub>gas (100 ppm) for 5 mins, an exposure that was established to alter airway function with minimal histological disruption of the epithelium. Twenty-four hours after exposure to Cl<sub>2</sub>, airway responsiveness to aerosolized methacholine (MCh) was measured. Bronchoalveolar lavage (BAL) was performed to determine inflammatory cell profiles, total protein, and glutathione levels. Dimethylthiourea (DMTU;100 mg/kg) was administered one hour before or one hour following Cl<sub>2 </sub>exposure.</p> <p>Results</p> <p>Mice exposed to Cl<sub>2 </sub>had airway hyperresponsiveness to MCh compared to control animals pre-treated and post-treated with DMTU. Total cell counts in BAL fluid were elevated by Cl<sub>2 </sub>exposure and were not affected by DMTU treatment. However, DMTU-treated mice had lower protein levels in the BAL than the Cl<sub>2</sub>-only treated animals. 4-Hydroxynonenal analysis showed that DMTU given pre- or post-Cl<sub>2 </sub>prevented lipid peroxidation in the lung. Following Cl<sub>2 </sub>exposure glutathione (GSH) was elevated immediately following exposure both in BAL cells and in fluid and this change was prevented by DMTU. GSSG was depleted in Cl<sub>2 </sub>exposed mice at later time points. However, the GSH/GSSG ratio remained high in chlorine exposed mice, an effect attenuated by DMTU.</p> <p>Conclusion</p> <p>Our data show that the anti-oxidant DMTU is effective in attenuating Cl<sub>2 </sub>induced increase in airway responsiveness, inflammation and biomarkers of oxidative stress.</p

    Saudi international students’ perceptions of their transition to the UK and the impact of social media

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    In their transition to a new country, international students often feel lost, anxious or stressed. Saudi students in the UK in particular may face further challenges due to the cultural, social and religious differences that they experience. There is a lot of evidence that social media play a crucial role in this experience. By interviewing 12 Saudi students from different cities in the UK, the aim of this study is to investigate how they perceive their transition to the UK and how social media is involved. The analysis indicates that Saudi students’ perceptions of transition tend to fall in to one of two markedly different camps. Some students see transition as an opportunity to detach themselves from their home country and to engage with the new society. Those students turn to social media as a tool allowing them to build bridges with the new society. Other students feel less enthusiastic to make a full engagement with the UK society. Those students find social media as a good tool to maintain connections and links with family and friends in their home country
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