1,278 research outputs found

    Effects of adaptation, chance, and history on the evolution of the toxic dinoflagellate Alexandrium minutum under selection of increased temperature and acidification

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    The roles of adaptation, chance, and history on evolution of the toxic dinoflagellate Alexandrium minutum Halim, under selective conditions simulating global change, have been addressed. Two toxic strains (AL1V and AL2V), previously acclimated for two years at pH 8.0 and 20◦C, were transferred to selective conditions: pH 7.5 to simulate acidification and 25◦C. Cultures under selective conditions were propagated until growth rate and toxin cell quota achieved an invariantmean value at 720 days (ca. 250 and ca. 180 generations for strains AL1V and AL2V, respectively). Historical contingencies strongly constrained the evolution of growth rate and toxin cell quota, but the forces involved in the evolution were not the same for both traits. Growth rate was 1.5–1.6 times higher than the one measured in ancestral conditions. Genetic adaptation explained two-thirds of total adaptation while one-third was a consequence of physiological adaptation. On the other hand, the evolution of toxin cell quota showed a pattern attributable to neutralmutations because the final varianceswere significantly higher than thosemeasured at the start of the experiment. It has been hypothesized that harmful algal blooms will increase under the future scenario of global change. Although this study might be considered an oversimplification of the reality, it can be hypothesized that toxic blooms will increase but no predictions can be advanced about toxicity.Universidad de Málaga. Campus de excelencia internacional. Andalucia Tech. Financially supported by the Spanish Ministry of Science and Innovation by the grant CGL2008-00652/BOS, and Junta de Andalucía Research Group RNM-115

    State anxiety improves prediction of pain and pain-related disability after 12 weeks in patients with acute low back pain:a cohort study

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    Question: Do measures of state anxiety and trait anxiety in people with acute low back pain (ALBP) improve prediction of chronic low back pain (CLBP), defined as pain or pain-related disability at 12 weeks? Design: Observational multi-centre prospective cohort study in primary physiotherapy care with measurements at baseline and at 12 weeks of state and trait anxiety, as well as other established prognostic factors for CLBP. Participants: People with nonspecific ALBP, aged 18 to 60 years, who had been pain free for ≥ 3 months before their current ALBP, and who were being treated according the Dutch clinical guidelines. Outcome measures and analysis: CLBP was defined as a pain score ≥ 3/10 on the Numerical Pain Rating Scale (primary outcome), and as a pain-related disability score ≥ 19/70 on the Pain Disability Inventory. Univariate and multivariate logistic regression analyses estimated how the risk of CLBP differed with state and trait anxiety and other established prognostic factors. Results: Most (204 of 225) participants completed both assessments. State anxiety was an independent predictor of CLBP, whether defined as pain or pain-related disability at 12 weeks, in contrast to trait anxiety. State anxiety improved the predictive performance of the model, with area under the curve (AUC) increasing from 0.64 (95% CI 0.56 to 0.71) to 0.75 (95% CI 0.68 to 0.82) and Nagelkerke's R2 increasing from 0.08 to 0.24 for the primary outcome measure, pain. For the secondary outcome measure, pain-related disability: AUC 0.63 (95% CI 0.54 to 0.72) improved to 0.73 (95% CI 0.65 to 0.82) and Nagelkerke's R2 increased from 0.05 to 0.16. Adding trait anxiety to the prognostic model for pain improved the AUC from 0.64 (95% CI 0.56 to 0.71) to 0.70 (95% CI 0.62 to 0.77) and Nagelkerke's R2 from 0.08 to 0.15. Conclusion: State anxiety in patients with ALBP improved prediction of CLBP, defined as pain and pain-related disability at 12 weeks

    Expectations about recovery from acute non-specific low back pain predict absence from usual work due to chronic low back pain:a systematic review

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    Question: Do negative expectations in patients after the onset of acute low back pain increase the odds of absence from usual work due to progression to chronic low back pain? Design: Systematic review with meta-analysis of prospective inception cohort studies. Participants: Adults with acute or subacute non-specific low back pain. Outcome measure: Absence from usual work at a given time point greater than 12 weeks after the onset of pain due to ongoing pain. Results: Ten studies involving 4683 participants were included in the review. Participants with acute or subacute pain and negative expectations about their recovery had significantly greater odds of being absent from usual work at a given time point more than 12 weeks after the onset of pain: OR 2.17 (95% CI 1.61 to 2.91). The exclusion of five studies with the greatest risk of bias showed that the result was similar when more rigorous quality criteria were applied: OR 2.52 (95% CI 1.47 to 4.31). Conclusion: The odds that adults with acute or subacute non-specific low back pain and negative recovery expectations will remain absent from work due to progression to chronic low back pain are two times greater than for those with more positive expectations. These results were consistent across the included studies despite variations in the risk of bias. [Hallegraeff JM, Krijnen WP, van der Schans CP, de Greet MHG (2012) Expectations about recovery from acute non-specific low back pain predict absence from usual work due to chronic low back pain: a systematic review. Journal of Physiotherapy 58:165-172]

    A clear definition of nocturnal leg cramps is essential for comparability of research

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    In 2012, our randomised trial demonstrated that stretching before sleep reduces the frequency and severity of nocturnal leg cramps in older adults.1 These episodic cramp attacks are characteristic: painful, sustained, involuntary muscle contractions of the calf muscles, hamstrings or feet. The sharp and intense pain may last from seconds to several minutes, accompanied by firm and tender muscles, and in some cases, with plantar flexion of feet and toes.2–5 In his letter, Garrison argues that prophylactic stretching is unlikely to prevent nocturnal leg cramps

    Hungry or Stressed? Relationship between Stress and Attention for Food-related Words

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    Obesity is a major health problem in western society and caused by different factors. Stress-induced eating is widely thought to increase the risk for obesity. The purpose of this study was to investigate the influence of stress on attention for food. We hypothesized that stress creates an attentional bias for high-caloric food, which can be assessed by an adapted Stroop task. This is measured by comparing reaction times for food-related words and non-food related words before and after stress. Against our expectations, we found that stress had no significantly different effect on the food word list compared to the neutral word list. Stressed and non-stressed participants turned out to be significantly slower on the food-word list than on the neutral-word list and participants were generally faster on both lists after stress. Taken together, our results show that the attentional bias for high-caloric food is not influenced by stress

    Illness perceptions as an independent predictor of chronic low back pain and pain-related disability:a prospective cohort study

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    OBJECTIVES: To investigate whether illness perceptions, measured with the Brief Illness Perception Questionnaire, are an independent predictor of chronic low back pain and pain-related disability at 12 weeks. DESIGN: A prospective, observational cohort study. SETTING: 26 outpatient primary care physiotherapy practices throughout the Netherlands. PARTICIPANTS: Acute nonspecific low back pain patients between the age of 18 and 60 years, with or without radiating pain, and a pain-free episode of at least three months before onset. INTERVENTIONS: Standard physiotherapy care according to Dutch clinical practice guidelines. OUTCOME MEASURE: Chronic low back pain defined as pain ≥3/10 on the Numeric Pain Rating Scale and as pain-related disability ≥19/70 on the Pain Disability Index measured after 12 weeks. RESULTS: Two hundred and four people with acute nonspecific low back pain completed both assessments. In the multivariable analyses, adjusted for pain intensity, disability, duration, radiating pain, depressed mood, associations of illness perceptions were OR 1.04 (95% CI: 1.01 to 1.08) for pain and 1.04 (95% CI: 0.99 to 1.09) for pain-related disability. CONCLUSIONS: Illness perceptions independently predicted chronic low back pain but not pain-related disability at 12 weeks. The added predictive value of illness perceptions was relatively low

    Australian dust storm associated with extensive Aspergillus sydowii fungal "Bloom" in coastal waters

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    A massive central Australian dust storm in September 2009 was associated with abundant fungal spores (150,000/m(3)) and hyphae in coastal waters between Brisbane (27 degrees S) and Sydney (34 degrees S). These spores were successfully germinated from formalinpreserved samples, and using molecular sequencing of three different genes (the large subunit rRNA gene [LSU], internal transcribed spacer [ITS], and beta-tubulin gene), they were conclusively identified as Aspergillus sydowii, an organism circumstantially associated with gorgonian coral fan disease in the Caribbean. Surprisingly, no human health or marine ecosystem impacts were associated with this Australian dust storm event. Australian fungal cultures were nontoxic to fish gills and caused a minor reduction in the motility of Alexandrium or Chattonella algal cultures but had their greatest impacts on Symbiodinium dinoflagellate coral symbiont motility, with hyphae being more detrimental than spores. While we have not yet seen any soft coral disease outbreaks on the Australian Great Barrier Reef similar to those observed in the Caribbean and while this particular fungal population was non-or weakly pathogenic, our observations raise the possibility of future marine ecosystem pathogen impacts from similar dust storms harboring more pathogenic strains
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