6 research outputs found

    Combining Thermodynamics-based Model of the Centrifugal Compressors and Active Machine Learning for Enhanced Industrial Design Optimization

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    The design process of centrifugal compressors requires applying an optimization process which is computationally expensive due to complex analytical equations underlying the compressor's dynamical equations. Although the regression surrogate models could drastically reduce the computational cost of such a process, the major challenge is the scarcity of data for training the surrogate model. Aiming to strategically exploit the labeled samples, we propose the Active-CompDesign framework in which we combine a thermodynamics-based compressor model (i.e., our internal software for compressor design) and Gaussian Process-based surrogate model within a deployable Active Learning (AL) setting. We first conduct experiments in an offline setting and further, extend it to an online AL framework where a real-time interaction with the thermodynamics-based compressor's model allows the deployment in production. ActiveCompDesign shows a significant performance improvement in surrogate modeling by leveraging on uncertainty-based query function of samples within the AL framework with respect to the random selection of data points. Moreover, our framework in production has reduced the total computational time of compressor's design optimization to around 46% faster than relying on the internal thermodynamics-based simulator, achieving the same performance.Comment: Accepted after peer-review at the 1st workshop on Synergy of Scientific and Machine Learning Modeling, SynS & ML ICML, Honolulu, Hawaii, USA. July, 2023. Copyright 2023 by the author(s

    Tackling frailty and functional decline: Background of the action group A3 of the European innovation partnership for active and healthy ageing

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    Ageing populations represent a challenge to the sustainability of current healthcare systems. The need to balance these demographic changes with gains in healthy life years and quality of life (QoL) constitutes an additional challenge. Aware of this, the European Commission (EC) launched the European Innovation Partnership on Active and Healthy Ageing (EIPonAHA) in 2012. The EIPonAHA is an interdisciplinary and cross-sector initiative involving more than 3000 partners with two specific objectives: to increase the healthy life expectancy of Europeans by two years by 2020, while increasing their QoL. The initiatives of the EIPonAHA have been organized according to six thematic action groups (AGs), with the A3 group targeting areas relating to the prevention of functional decline and frailty. In addition to the good practices of partners, there are several on-going collaborative works. The involvement of the EC includes support through an elaborated research programme in which the Consumers, Health, Agriculture and Food Executive Agency (CHAFEA) and the Directorate-General for Communications Networks, Content and Technology (DG CONNECT) are the main funding bodies. Screening approaches and preventive interventions constitute most of the initiatives within the A3 AG. Partners are distributed across five sub-groups according to good practices: i) cognitive decline, ii) food and nutrition, iii) physical activity, iv) caregivers, and v) frailty and functional decline. Regular updates of the progression of both good practices and collaborative works are presented in A3 AG meetings. The 2017 meeting in Valencia, Spain, showcased in this paper, provides an up-to-date overview of the current status of A3 activities.Frailty management Optimisation through EIPAHA Commitments and Utilisation of Stakeholders input (FOCUS) project; Consumers, Health, Agriculture and Food Executive Agency (CHAFEA) [664367

    Confirmatory factor analysis of the Patient Assessment of Constipation-Symptoms (PAC-SYM) among patients with chronic constipation

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    Background and aim: PAC-SYM is widely adopted to asses constipation severity. However, it has been validated in a small sample, few items have been included based on expert opinion and not on empirical grounds, and its factor structure has never been replicated. We aimed at evaluating the psychometric properties of PAC-SYM in patients with chronic constipation. Methods: We enrolled 2,203 outpatients with chronic constipation in two waves. We used wave I sample to test the psychometric properties of the PAC-SYM and wave II sample to cross-validate its factor structure, to assess criterion validity, responsiveness to clinical change, and its minimal clinically important difference. Results: Only a minority of patients reported any rectal tearing (38 %). Deletion of such item leads to a 11-item version (M:PAC-SYM). The remaining items in the rectal domain were moderately correlated with the stool domain. Exploratory factor analysis and confirmatory factor analysis revealed a bifactor structure with two subscales (stool and abdominal symptoms) and a general severity factor. The M:PAC-SYM demonstrated excellent reliability, moderate correlation with SF-12 and treatment satisfaction (r = 0.28-0.45), discrimination across Rome III criteria for functional constipation and abdominal pain, and responsiveness to clinical change (ÎČ = -0.49; ω2 = 0.25). M:PAC-SYM minimal clinically important difference was 0.24. Conclusion: Our analysis shows that the rectal domain may not represent a relevant cluster of symptoms for patients with chronic constipation. We developed a modified version of the PAC-SYM which might better represent symptom severity of most patients seeking care in gastroenterology referral centers

    Bloating is associated with worse quality of life, treatment satisfaction, and treatment responsiveness among patients with constipation-predominant irritable bowel syndrome and functional constipation

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    Background: The management of bloating is unclear and its relationship with patients' well-being and treatment satisfaction independent of other abdominal symptoms is uncharacterized. We evaluated the association of bloating with patient-reported outcomes. Methods: Thirty-nine centers for functional gastrointestinal disorders joined the laxative inadequate relief survey. We enrolled 2203 consecutive outpatients with functional constipation (FC) or constipation-predominant irritable bowel syndrome (IBS-C) in two cross-sectional waves. Both wave 1 and 2 included the SF-12, the patient assessment of constipation-symptoms (PAC-SYM), and the treatment satisfaction questionnaire for medication (TSQM-2). Wave 2 only included a global rating of change (GRC) scale to assess patients' assessment of efficacy concerning treatment switches occurred in the 3 months prior to the interview. Bloating in the abdomen was defined on the basis of PAC-SYM item 3. Key Results: The average age was 50.1 years (SD, 16.7) and 82.1% of patients were women. The prevalence of bloating was 91.6% (n = 1970). Bloating was associated with SF-12 Physical Composite Score (p < 0.01), SF-12 Mental Composite Score (p < 0.01), GRC (p < 0.01), Satisfaction with treatment effectiveness (p < 0.01), convenience of administration (p < 0.01), and side effects (p < 0.01) after adjustment for possible confounders. Conclusions & Inferences: Our data suggest that patients regard bloating as a key element in assessing clinical changes and treatments' efficacy as this symptom exerts a strong influence on patient-reported outcomes independent of possible confounders and other symptoms of constipation. Our data provide the rationale to investigate the efficacy and tolerability of new treatments specifically addressing this important, yet disregarded, patients' complain

    Effects of pre‐operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study

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    We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05-1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4-7 days or >= 8 days of 1.25 (1.04-1.48), p = 0.015 and 1.31 (1.11-1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care
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