9 research outputs found

    Do we need photonic-based instruments to characterize multiscale processes in marine environments?

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    Ocean Optics XXI, 8-12 October 2012, Glasgow, Scotland, United KingdomTime- or space-series analysis is the one of the essential methods for marine science to understand the dynamics of ocean processes. It not only helps to identify the phenomenon represented by sequences of observations, but also helps to forecast events by feeding models. One of the first questions to address regarding the sampling strategy to obtain a time/space data series is the sampling frequency and the number of samples to measure. In many cases the answers to these questions are based mainly on logistic or operational restrictions (maximum number of samples that it is possible to process, instrumental capabilities, etc.). However, it is important to take into account the principles of Information Theory in order to avoid potential artefacts derived from improper sampling design. Furthermore, in those cases where the processes are not stationary (a common situation in marine environments) the sampling frequency and the number of samples play an important role in determining the time-frequency resolution required to characterize their dynamical properties. To address these problems of scale, two data sets are used as examples: (a) the analysis of a time series measured 3 samples/hr by the Imaging FlowCytobot (IFCB) installed at the entrance to the Mission-Aransas estuary (Port Aransas, TX, USA) during 2008 and (b) the high resolution spatial series of fluorescence data obtained 1 sample/m with an autonomous underwater vehicle (AUV) in Alfacs Bay (Ebro delta, Spain) during 2011. The final results indicate the need for measurements with sampling rates much higher than those commonly used in conventional methods (such as those relying on manual microscopy or pigment analysis) even in those cases in which the main goal is to characterize the dynamics at large spatial (order of km) or temporal (order of month-year) scales. These results reinforce the idea that the regular use of photonic-based instruments (optical, imaging or holographic systems) is necessary to characterize multiscale processes in marine environments due to the fact that, at present time, these are the only technologies capable of sampling at the required ratesPeer Reviewe

    Anticipatory anxiety and participation in cancer screening. A systematic review

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    ObjectivesTo synthesize current evidence on the association between anticipatory anxiety, defined as apprehension-specific negative affect that may be experienced when exposed to potential threat or uncertainty, and cancer screening to better inform strategies to maximize participation rates.MethodsSearches related to cancer screening and anxiety were conducted in seven electronic databases (APA PsycINFO, Scopus, Web of Science, Embase, Cochrane Library, PubMed, CINAHL), with potentially eligible papers screened in Covidence. Data extraction was conducted independently by multiple authors. Barriers to cancer screening for any type of cancer and relationships tested between anticipatory anxiety and cancer screening and intention were categorized and compared according to the form and target of anxiety and cancer types.ResultsA total of 74 articles (nparticipants = 119,990) were included, reporting 103 relationships tested between anticipatory anxiety and cancer screening and 13 instances where anticipatory anxiety was reported as a barrier to screening. Anticipatory anxiety related to a possible cancer diagnosis was often associated with increased screening, while general anxiety showed no consistent relationship. Negative relationships were often found between anxiety about the screening procedure and cancer screening.ConclusionAnticipatory anxiety about a cancer diagnosis may promote screening participation, whereas a fear of the screening procedure could be a barrier. Public health messaging and primary prevention practitioners should acknowledge the appropriate risk of cancer, while engendering screening confidence and highlighting the safety and comfort of screening tests

    Prospective observational cohort study on grading the severity of postoperative complications in global surgery research

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    Background The Clavien–Dindo classification is perhaps the most widely used approach for reporting postoperative complications in clinical trials. This system classifies complication severity by the treatment provided. However, it is unclear whether the Clavien–Dindo system can be used internationally in studies across differing healthcare systems in high- (HICs) and low- and middle-income countries (LMICs). Methods This was a secondary analysis of the International Surgical Outcomes Study (ISOS), a prospective observational cohort study of elective surgery in adults. Data collection occurred over a 7-day period. Severity of complications was graded using Clavien–Dindo and the simpler ISOS grading (mild, moderate or severe, based on guided investigator judgement). Severity grading was compared using the intraclass correlation coefficient (ICC). Data are presented as frequencies and ICC values (with 95 per cent c.i.). The analysis was stratified by income status of the country, comparing HICs with LMICs. Results A total of 44 814 patients were recruited from 474 hospitals in 27 countries (19 HICs and 8 LMICs). Some 7508 patients (16·8 per cent) experienced at least one postoperative complication, equivalent to 11 664 complications in total. Using the ISOS classification, 5504 of 11 664 complications (47·2 per cent) were graded as mild, 4244 (36·4 per cent) as moderate and 1916 (16·4 per cent) as severe. Using Clavien–Dindo, 6781 of 11 664 complications (58·1 per cent) were graded as I or II, 1740 (14·9 per cent) as III, 2408 (20·6 per cent) as IV and 735 (6·3 per cent) as V. Agreement between classification systems was poor overall (ICC 0·41, 95 per cent c.i. 0·20 to 0·55), and in LMICs (ICC 0·23, 0·05 to 0·38) and HICs (ICC 0·46, 0·25 to 0·59). Conclusion Caution is recommended when using a treatment approach to grade complications in global surgery studies, as this may introduce bias unintentionally

    The surgical safety checklist and patient outcomes after surgery: a prospective observational cohort study, systematic review and meta-analysis

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    © 2017 British Journal of Anaesthesia Background: The surgical safety checklist is widely used to improve the quality of perioperative care. However, clinicians continue to debate the clinical effectiveness of this tool. Methods: Prospective analysis of data from the International Surgical Outcomes Study (ISOS), an international observational study of elective in-patient surgery, accompanied by a systematic review and meta-analysis of published literature. The exposure was surgical safety checklist use. The primary outcome was in-hospital mortality and the secondary outcome was postoperative complications. In the ISOS cohort, a multivariable multi-level generalized linear model was used to test associations. To further contextualise these findings, we included the results from the ISOS cohort in a meta-analysis. Results are reported as odds ratios (OR) with 95% confidence intervals. Results: We included 44 814 patients from 497 hospitals in 27 countries in the ISOS analysis. There were 40 245 (89.8%) patients exposed to the checklist, whilst 7508 (16.8%) sustained ≥1 postoperative complications and 207 (0.5%) died before hospital discharge. Checklist exposure was associated with reduced mortality [odds ratio (OR) 0.49 (0.32–0.77); P\u3c0.01], but no difference in complication rates [OR 1.02 (0.88–1.19); P=0.75]. In a systematic review, we screened 3732 records and identified 11 eligible studies of 453 292 patients including the ISOS cohort. Checklist exposure was associated with both reduced postoperative mortality [OR 0.75 (0.62–0.92); P\u3c0.01; I2=87%] and reduced complication rates [OR 0.73 (0.61–0.88); P\u3c0.01; I2=89%). Conclusions: Patients exposed to a surgical safety checklist experience better postoperative outcomes, but this could simply reflect wider quality of care in hospitals where checklist use is routine

    Critical care admission following elective surgery was not associated with survival benefit: prospective analysis of data from 27 countries

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    This was an investigator initiated study funded by Nestle Health Sciences through an unrestricted research grant, and by a National Institute for Health Research (UK) Professorship held by RP. The study was sponsored by Queen Mary University of London

    Nitrogen excretion in insects

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