36 research outputs found

    Towards Machine Wald

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    The past century has seen a steady increase in the need of estimating and predicting complex systems and making (possibly critical) decisions with limited information. Although computers have made possible the numerical evaluation of sophisticated statistical models, these models are still designed \emph{by humans} because there is currently no known recipe or algorithm for dividing the design of a statistical model into a sequence of arithmetic operations. Indeed enabling computers to \emph{think} as \emph{humans} have the ability to do when faced with uncertainty is challenging in several major ways: (1) Finding optimal statistical models remains to be formulated as a well posed problem when information on the system of interest is incomplete and comes in the form of a complex combination of sample data, partial knowledge of constitutive relations and a limited description of the distribution of input random variables. (2) The space of admissible scenarios along with the space of relevant information, assumptions, and/or beliefs, tend to be infinite dimensional, whereas calculus on a computer is necessarily discrete and finite. With this purpose, this paper explores the foundations of a rigorous framework for the scientific computation of optimal statistical estimators/models and reviews their connections with Decision Theory, Machine Learning, Bayesian Inference, Stochastic Optimization, Robust Optimization, Optimal Uncertainty Quantification and Information Based Complexity.Comment: 37 page

    Disclosing the truth to terminal cancer patients: A discussion of ethical and cultural issues [Divulgation de la vérité aux patients atteints d'un cancer en phase terminale: Discussion sur les problèmes éthiques et culturels]

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    One of the most difficult ethical dilemmas facing health care professionals working in oncology is whether, when, how and how much to tell terminal cancer patients about their diagnosis and prognosis. The aim of this article is to review the trends in this issue worldwide. While a majority of physicians in both developed and developing countries tell the truth more often today than in the past, the assumption that truth-telling is always beneficial to patients can be questioned. The issue of truth-telling is still approached differently in different countries and cultures and there is a need for an increased awareness of cultural differences to truth-telling among patients from ethnic minorities

    Single-center experience with remote endarterectomy for the treatment of long-segment superficial femoral artery occlusion: Long-term results

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    Objectives: Remote endarterectomy (RE) is a relatively minimally invasive procedure as an alternative to femoropopliteal above-knee bypass for the treatment of long-segment superficial femoral artery (SFA) occlusion. The objective of this study was to report our experience and to evaluate the long-term outcome. Design: Single-center nonrandomized retrospective study with prospective collection of patients' data. Methods: Twelve patients (11 men; mean age 72 years, range 55-81 years) with long (>10 cm) SFA occlusion underwent RE followed by stent (aSpire) placement at the distal end of the endarterectomy. All patients had at least 2 tibial vessels outflow. Indications were severe claudication in 9 (75%), rest pain in 1(8%), and gangrene in 2 (17%) cases. Technical, hemodynamic success rates and clinical improvement were recorded. Assessment of patency and limb loss was made at a mean follow-up of 50 months (range 12-66 months). Results: Technical success rate was 100%. Immediate hemodynamic and clinical improvement were 92% and 75%, respectively. The mean increase in the Ankle-Brachial pressure index was 0.24. The primary, primary-assisted, and secondary patency rates were 50%, 83%, and 100%, respectively. The perioperative mortality rate was 8% (one death due to myocardial infarction). There was no early (30-day) reocclusion. During the follow-up, 5 (41.6%) cases underwent 7 reinterventions, all by endovascular means. The amputation rate was 16% (2 of 12). Conclusions: The RE for long SFA occlusion is a feasible procedure with acceptable short- and long-term outcomes in the presence of distal arterial outflow. Good long-term patency and limb salvage can be achieved with close surveillance and with the compensation of endovascular reintervention procedures. © The Author(s) 2015

    Rare earths as authenticity markers for the discrimination of Greek and Turkish pistachios using elemental metabolomics and chemometrics

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    Pistachios are a nutritionally beneficial food source widely consumed all over the world. Pistachios exhibit high content of antioxidants, vitamins and other beneficial micronutrients, including nutrient elements and rare earth elements (REEs). Considering that the concentration of REEs depends on the climate and soil characteristics that vary among different geographical regions, REEs could constitute markers responsible for the geographical discrimination of this nut type. In this study, Greek pistachios with a protected designation of origin (PDO) label from Aegina Island and Fthiotida and Turkish pistachios from Adana were analyzed with inductively coupled plasma mass spectrometry (ICP-MS) to assess their REE profile. La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb were determined and quantified. The quantification results were further analyzed using the main effect plot, permutational analysis of variance (PERMANOVA), nonmetric multidimensional scaling (nMDS), principal component analysis (PCA) and hierarchical clustering (HCA) to investigate the similarities between the pistachios. A decision tree (DT) was developed for the classification of pistachios according to their geographical origin proving to be a promising and reliable tool for verifying the authenticity of food products on the basis of their REE profile. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Hybrid procedures for chronic lower limb ischemia: What determines the outcome?

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    BACKGROUND: To report the long term outcome of hybrid (combined open and endovascular) procedures for the management of multisegmental chronic peripheral arterial disease. METHODS: A retrospective analysis from a single center during the period 2009-2013. Patency rates, survival and limb salvage were the primary outcomes. Univariate and multivariate analyses were used to assess the association with various factors. RESULT S: A total of 132 patients (116 males) with mean age of 69±1.4 years, were treated. The technical and hemodynamic success rates were 94% and 97.7% respectively. The primary and assisted primary patency rates in 36 months were 69.7% and 94.7%, respectively. The Hazard Ratio for primary and assisted primary patency failure was 1.94 (95% CI: 1.07-3.51, P=0.029) and 5.55 (95% CI: 1.15-26.79, P=0.033) times higher in diabetic patients, respectively. Limb salvage rate in 36 months was 87.9%. Rutherford category (P=0.046) and previous ipsilateral reconstruction (P=0.011) were the only factors associated with limb loss. CONCLUSIONS: Hybrid procedures are associated with good long term outcomes in the treatment of multisegmental chronic peripheral arterial disease. Diabetes mellitus remains a determinant of worse outcome, while the severity of the disease and previous ipsilateral revascularization are associated with poorer limb salvage

    Balloon Angioplasty Versus Stenting for the Treatment of Failing Arteriovenous Grafts: A Meta-Analysis

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    Purpose: To assess the outcomes of plain balloon angioplasty versus stenting for the treatment of failed or malfunctioning chronic haemodialysis arteriovenous grafts (AVGs). Methods: A systematic search of the literature was undertaken using the PUBMED, EMBASE, and Cochrane databases from January 2000 to September 2016 for articles comparing balloon angioplasty versus stenting in the management of failed or malfunctioning chronic haemodialysis AVGs. Results are reported as OR and 95% CI. Results: The search identified eight studies (1051 patients). Balloon angioplasty alone was used in 521 patients (49.6%) and stenting in 530 patients (50.4%). At the time of the endovascular re-intervention, the mean life of AVGs was 807.7±115.4 days for the balloon angioplasty and 714.2±96.3 days for the stenting group (p=.92). All AVGs were located in the arm. Most procedures (98.1%) were performed across the venous anastomosis, while 88% of the patients in the stenting group received a stent graft. The technical success rate was significantly higher in the stenting group (OR 0.16, 95% CI 0.08–0.31, p<.001). At 12 months, loss of primary and secondary patency was significantly higher in patients undergoing plain balloon angioplasty compared with stenting (OR 3.54, 95% CI 2.18–5.74, p<.001, and OR 1.82, 95% 1.17–2.82, p=.008, respectively). Conclusion: Stenting is associated with better technical success and patency rates compared with plain angioplasty in treating failed or malfunctioning chronic haemodialysis AVGs, and thus it should be considered as the first line therapeutic option. © 2017 European Society for Vascular Surger

    The Effectiveness of Spinal, Diaphragmatic, and Specific Stabilization Exercise Manual Therapy and Respiratory-Related Interventions in Patients with Chronic Nonspecific Neck Pain: Systematic Review and Meta-Analysis

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    Patients with nonspecific chronic neck pain (NSCNP) exhibit respiratory dysfunction. This systematic review aimed to analyze randomized controlled trials (RCTs) investigating the effect of spinal and/or diaphragmatic and/or specific stabilization exercise manual therapy and/or respiratory exercises on musculoskeletal and respiratory diagnostic outcomes in patients with NSCNP. A systematic search and selection of RCTs was performed in three scientific databases (Pubmed, Scopus, and Physiotherapy Evidence Database (PEDro)) and one search engine (Google Scholar) from inception to April 2022. Relevant studies published in the English language were extracted, evaluated, and independently rated for methodological quality (PEDro scale). The quality of the evidence was assessed with the GRADE approach. Out of 1089 studies collected in total, 1073 were excluded (i.e., did not meet the inclusion criteria or were duplicates). Sixteen RCTs were finally included, rated on 5.62/10 (PEDro score) on average for methodological quality. Overall, there was sparse evidence that spinal and/or diaphragmatic manual therapy and/or trunk stabilization exercises and/or respiratory exercises significantly improved pain, disability, and respiratory outcomes in patients with NSCNP immediately post-treatment. However, the clinical heterogeneity between studies was significant, and the level of certainty of the evidence was low to very low. More, high-quality RCTs are required, contributing to the holistic diagnostic monitoring and management of patients with NSCNP. © 2022 by the authors. Licensee MDPI, Basel, Switzerland
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