9 research outputs found

    Nonergodicity in protective factors of resilience in athletes

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    Resilience is a key construct to understand when athletes continue to perform optimally, or when they break down. Although there is consensus that resilience can be conceptualized as a dynamic process, it remains an open question whether studying such a process on a group level adequately represents the individuals within a given sample. As a first step to answer this question, we designed a diary study to test whether the statistics for repeated assessments of protective factors and resilience can be generalized from group-level trajectories to the individuals. By tracking resilience and the protective factors over 21 days in athletes, we found divergent patterns of group-level and individual-level statistics for the repeated assessments. This so-called "ergodicity problem" implies that the individual, rather than the group, should be placed at the level of analysis to avoid wrong conclusions and ineffective interventions on their resilience

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    We present a thorough investigation on using machine learning to construct effective personalized anti-spam filters. The investigation includes four learning algorithms, Naive Bayes, Flexible Bayes, LogitBoost, and Support Vector Machines, and four datasets, constructed from the mailboxes of different users. We discuss the model and search biases of the learning algorithms, along with worst-case computational complexity figures, and observe how the latter relate to experimental measurements. We study how classification accuracy is affected when using attributes that represent sequences of tokens, as opposed to single tokens, and explore the effect of the size of the attribute and training set, all within a cost-sensitive framework. Furthermore, we describe the architecture of a fully implemented learning-based anti-spam filter, and present an analysis of its behavior in real use over a period of seven months. Information is also provided on other available learning-based anti-spam filters, and alternative filtering approaches

    Filtron: A Learning-Based Anti-Spam Filter

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    We present Filtron, a prototype anti-spam filter that integrates the main empirical conclusions of our comprehensive analysis on using machine learning to construct e#ective personalized anti-spam filters. Filtron is based on the experimental results over several design parameters on four publicly available benchmark corpora. After describing Filtron's architecture, we assess its behavior in real use over a period of seven months. The results are deemed satisfactory, though they can be improved with more elaborate preprocessing and regular re-training

    The Evolution of Living Donor Nephrectomy Program at A Hellenic Transplant Center. Laparoscopic vs. Open Donor Nephrectomy: Single-Center Experience

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    Since its introduction in 1995, laparoscopic nephrectomy has emerged as the preferred surgical approach for living donor nephrectomy. Given the ubiquity of the surgical procedure and the need for favorable outcomes, as it is an elective operation on otherwise healthy individuals, it is imperative to ensure appropriate preoperative risk stratification and anticipate intraoperative challenges. The aim of the present study was to compare peri-and postoperative outcomes of living kidney donors (LD), who had undergone laparoscopic nephrectomy (LDN), with a control group of those who had undergone open nephrectomy (ODN). Health-related quality of life (QoL) was also assessed using the validated SF-36 questionnaire. Data from 252 LD from a single transplant center from March 2015 to December 2020 were analyzed retrospectively. In total, 117 donors in the LDN and 135 in the ODN groups were assessed. Demographics, type of transplantation, BMI, duration of surgery, length of hospital stay, peri- and postoperative complications, renal function at discharge and QoL were recorded and compared between the two groups using Stata 13.0 software. There was no difference in baseline characteristics, nor in the prevalence of peri-and postoperative complications, with a total complication rate of 16% (mostly minor, Clavien–Dindo grade II) in both groups, while a different pattern of surgical complications was noticed between them. Duration of surgery was significantly longer in the ODN group (median 240 min vs. 160 min in LDN, p < 0.01), warm ischemia time was longer in the LDN group (median 6 min vs.2 min in ODN, p < 0.01) and length of hospital stay shorter in the LDN group (median 3 days vs. 7 days in ODN). Conversion rate from laparoscopic to open surgery was 2.5%. There was a drop in estimated glomerular filtration rate (eGFR) at discharge of 36 mL/min in the LDN and 32 mL/min in the ODN groups, respectively (p = 0.03). No death, readmission or reoperation were recorded. There was a significant difference in favor of LDN group for each one of the eight items of the questionnaire (SF1–SF8). As for the two summary scores, while the total physical component summary (PCS) score was comparable between the two groups (57.87 in the LDN group and 57.07 in the ODN group), the mental component summary (MCS) score was significantly higher (62.14 vs. 45.22, p < 0.001) in the LDN group. This study provides evidence that minimally invasive surgery can be performed safely, with very good short-term outcomes, providing several benefits for the living kidney donor, thereby contributing to expanding the living donor pool, which is essential, especially in countries with deceased-donor organ shortage

    Early Start of Oral Clarithromycin Is Associated with Better Outcome in COVID-19 of Moderate Severity: The ACHIEVE Open-Label Single-Arm Trial

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    Introduction The anti-inflammatory effect of macrolides prompted the study of oral clarithromycin in moderate COVID-19. Methods An open-label non-randomized trial in 90 patients with COVID-19 of moderate severity was conducted between May and October 2020. The primary endpoint was defined at the end of treatment (EOT) as no need for hospital re-admission and no progression into lower respiratory tract infection (LRTI) for patients with upper respiratory tract infection and as at least 50% decrease of the respiratory symptoms score without progression into severe respiratory failure (SRF) for patients with LRTI. Viral load, biomarkers, the function of mononuclear cells and safety were assessed. Results The primary endpoint was attained in 86.7% of patients treated with clarithromycin (95% CIs 78.1-92.2%); this was 91.7% and 81.4% among patients starting clarithromycin the first 5 days from symptoms onset or later (odds ratio after multivariate analysis 6.62; p 0.030). The responses were better for patients infected by non-B1.1 variants. Clarithromycin use was associated with decreases in circulating C-reactive protein, tumour necrosis factor-alpha and interleukin (IL)-6; by increase of production of interferon-gamma and decrease of production of interleukin-6 by mononuclear cells; and by suppression of SARS-CoV-2 viral load. No safety concerns were reported. Conclusions Early clarithromycin treatment provides most of the clinical improvement in moderate COVID-19

    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
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