47 research outputs found

    Universal differential equations for glacier ice flow modelling

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    Geoscientific models are facing increasing challenges to exploit growing datasets coming from remote sensing. Universal differential equations (UDEs), aided by differentiable programming, provide a new scientific modelling paradigm enabling both complex functional inversions to potentially discover new physical laws and data assimilation from heterogeneous and sparse observations. We demonstrate an application of UDEs as a proof of concept to learn the creep component of ice flow, i.e. a nonlinear diffusivity differential equation, of a glacier evolution model. By combining a mechanistic model based on a two-dimensional shallow-ice approximation partial differential equation with an embedded neural network, i.e. a UDE, we can learn parts of an equation as nonlinear functions that then can be translated into mathematical expressions. We implemented this modelling framework as ODINN.jl, a package in the Julia programming language, providing high performance, source-to-source automatic differentiation (AD) and seamless integration with tools and global datasets from the Open Global Glacier Model in Python. We demonstrate this concept for 17 different glaciers around the world, for which we successfully recover a prescribed artificial law describing ice creep variability by solving ∼ 500 000 ordinary differential equations in parallel. Furthermore, we investigate which are the best tools in the scientific machine learning ecosystem in Julia to differentiate and optimize large nonlinear diffusivity UDEs. This study represents a proof of concept for a new modelling framework aiming at discovering empirical laws for large-scale glacier processes, such as the variability in ice creep and basal sliding for ice flow, and new hybrid surface mass balance models.</p

    Comparison of the information provided by electronic health records data and a population health survey to estimate prevalence of selected health conditions and multimorbidity

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    This is a freely-available open access publication. Please cite the published version which is available via the DOI link in this record.Background Health surveys (HS) are a well-established methodology for measuring the health status of a population. The relative merit of using information based on HS versus electronic health records (EHR) to measure multimorbidity has not been established. Our study had two objectives: 1) to measure and compare the prevalence and distribution of multimorbidity in HS and EHR data, and 2) to test specific hypotheses about potential differences between HS and EHR reporting of diseases with a symptoms-based diagnosis and those requiring diagnostic testing. Methods Cross-sectional study using data from a periodic HS conducted by the Catalan government and from EHR covering 80% of the Catalan population aged 15 years and older. We determined the prevalence of 27 selected health conditions in both data sources, calculated the prevalence and distribution of multimorbidity (defined as the presence of ≥2 of the selected conditions), and determined multimorbidity patterns. We tested two hypotheses: a) health conditions requiring diagnostic tests for their diagnosis and management would be more prevalent in the EHR; and b) symptoms-based health problems would be more prevalent in the HS data. Results We analysed 15,926 HS interviews and 1,597,258 EHRs. The profile of the EHR sample was 52% women, average age 47 years (standard deviation: 18.8), and 68% having at least one of the selected health conditions, the 3 most prevalent being hypertension (20%), depression or anxiety (16%) and mental disorders (15%). Multimorbidity was higher in HS than in EHR data (60% vs. 43%, respectively, for ages 15-75+, P <0.001, and 91% vs. 83% in participants aged ≥65 years, P <0.001). The most prevalent multimorbidity cluster was cardiovascular. Circulation disorders (other than varicose veins), chronic allergies, neck pain, haemorrhoids, migraine or frequent headaches and chronic constipation were more prevalent in the HS. Most symptomatic conditions (71%) had a higher prevalence in the HS, while less than a third of conditions requiring diagnostic tests were more prevalent in EHR. Conclusions Prevalence of multimorbidity varies depending on age and the source of information. The prevalence of self-reported multimorbidity was significantly higher in HS data among younger patients; prevalence was similar in both data sources for elderly patients. Self-report appears to be more sensitive to identifying symptoms-based conditions. A comprehensive approach to the study of multimorbidity should take into account the patient perspective.Ministry of Science and Innovation through the Instituto Carlos IIIISCiii-RETICSInstitut Universitari d’Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol

    Socio-economic status and the risk of developing hand, hip or knee osteoarthritis: a region-wide ecological study

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    SummaryObjectiveTo determine the association between socio-economic status (SES) and risk of hand, hip or knee osteoarthritis (OA) at a population level.DesignRetrospective ecological study using the System for the Development of Research in Primary Care (SIDIAP) database (primary care anonymized records for >5 million people in Catalonia (Spain)). Urban residents >15 years old (2009–2012) were eligible. Outcomes: Validated area-based SES deprivation index MEDEA (proportion of unemployed, temporary workers, manual workers, low educational attainment and low educational attainment among youngsters) was estimated for each area based on census data as well as incident diagnoses (ICD-10 codes) of hand, hip or knee OA (2009–2012). Zero-inflated Poisson models were fitted to study the association between MEDEA quintiles and the outcomes.ResultsCompared to the least deprived, the most deprived areas were younger (43.29 (17.59) vs 46.83 (18.49), years (Mean SD), had fewer women (49.1% vs 54.8%), a higher percentage of obese (16.2% vs 8.4%), smokers (16.9% vs 11.9%) and high-risk alcohol consumption subjects (1.5% vs 1.3%). Compared to the least deprived, the most deprived areas had an excess risk of OA: age-sex-adjusted Incidence Rate Ratio (IRR) 1.26 (1.11–1.42) for hand, 1.23 (1.17–1.29) hip, and 1.51 (1.45–1.57) knee. Adjustment for obesity attenuated this association: 1.06 (0.93–1.20), 1.04 (0.99–1.09), and 1.23 (1.19–1.28) respectively.ConclusionsDeprived areas have higher rates OA (hand, hip, knee). Their increased prevalence of obesity accounts for a 50% of the excess risk of knee OA observed. Public health interventions to reduce the prevalence of obesity in this population could reduce health inequalities

    Factors related to the development of health-promoting community activities in Spanish primary healthcare: two case-control studies.

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    Objective Spanish primary healthcare teams have the responsibility of performing health-promoting community activities (CAs), although such activities are not widespread. Our aim was to identify the factors related to participation in those activities. Design Two case–control studies. setting Performed in primary care of ve Spanish regions. subjects In the rst study, cases were teams that performed health-promoting CAs and controls were those that did not. In the second study (on case teams from the rst study), cases were professionals who developed these activities and controls were those who did not. Main outcome measures Team, professional and community characteristics collected through questionnaires (team managers/professionals) and from secondary sources. results The rst study examined 203 teams (103 cases, 100 controls). Adjusted factors associated with performing CAs were percentage of nurses (OR 1.07, 95% CI 1.01 to 1.14), community socioeconomic status (higher vs lower OR 2.16, 95% CI 1.18 to 3.95) and performing undergraduate training (OR 0.44, 95% CI 0.21 to 0.93). In the second study, 597 professionals responded (254 cases, 343 controls). Adjusted factors were professional classi cation (physicians do fewer activities than nurses and social workers do more), training in CAs (OR 1.9, 95% CI 1.2 to 3.1), team support (OR 2.9, 95% CI 1.5 to 5.7), seniority (OR 1.06, 95% CI 1.03 to 1.09), nursing tutor (OR 2.0, 95% CI 1.1 to 3.5), motivation (OR 3.7, 95% CI 1.8 to 7.5), collaboration with non-governmental organisations (OR 1.9, 95% CI 1.2 to 3.1) and participation in neighbourhood activities (OR 3.1, 95% CI 1.9 to 5.1). Conclusions Professional personal characteristics, such as social sensitivity, profession, to feel team support or motivation, have in uence in performing health-promoting CAs. In contrast to the opinion expressed by many professionals, workload is not related to performance of health-promoting CAs

    Conditions for research in general practice: can the Dutch and British experiences be applied to other countries, for example Spain?

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    The aim of this study is to identify conditions for research as part of professional development in general practice. Based on the work of Andrew Abbott, who studied the dynamics of professional development, five conditions were identified. These are: the creation of associations among professionals; control of work; the establishment of specialised education; the development of professional knowledge; and the creation of organised structures for professional work. Two countries with a well-established research tradition in general practice (the UK and the Netherlands) and one country where GP research development is still limited (Spain) were evaluated on the basis of these conditions. The conditions identified as favourable were as follows: the existence of a scientific association; a peer reviewed journal; a defined population resulting in a population denominator for practices; a gatekeeping system; chairs and departments of general practice at universities; the integration of education centres and research centres; GPs working in group practices or health centres; a certain degree of independence from the Ministry of Health; and financial support for practicing GPs to conduct research acitivities. We showed that most conditions for the successful scientific progress of general practice in Spain are present. However there is still a gap between academia and general practice and a lack of research organisation and support. (aut.ref.

    Variaciones en la aplicación de técnicas médicas en atención primaria.

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    Objectives: To describe the application of medical techniques (ATM) in Spain and to analyze the relationship with diverse characteristics related to general practitioners and the center of primary health care. Design: Multicenter cross-sectional study. Setting: Three hundred nineteen general practitioners working in primary care centers in the restructured public sector of the Autonomous Communities of Andalusia, Basque Country and Catalonia in Spain. Main measurements: Structured and validated questionnaire comprising 100 items in four sections: general charateristics of the physician and health center, task profile, and job satisfaction. The questionnaire was sent by mail to the health center (Andalusia and Basque Country) or to the home (Catalonia). For the analysis an index variable was created from the answers to the questions on AMT. Results: The index variable of AMT obtained a mean value of 10.02 (SD=4.55). Andalusia obtained the highest value (median: 11.11; SD: 4.33) of the three Autonomous Communities in the study (p=.012). AMT acquired significantly higher values when associated with: masculine sex (sample from the three autonomous communities: p=.046), rural environment, teamwork, availability of basic equipment, fewer patients, and reduced work load. Conclusions: Index of ATM in Spain is significantly different in the three Spanish communities under study. The quality of the sanitary services evaluated from the dimension of the ATM seems to be much related with demographic characteristics, the readiness in the consultations of ascientific-technical stuff and the appropriate time for medical consultations. (aut.ref.
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