1,246 research outputs found

    On the impact of covariance functions in multi-objective Bayesian optimization for engineering design

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordMulti-objective Bayesian optimization (BO) is a highly useful class of methods that can effectively solve computationally expensive engineering design optimization problems with multiple objectives. However, the impact of covariance function, which is an important part of multi-objective BO, is rarely studied in the context of engineering optimization. We aim to shed light on this issue by performing numerical experiments on engineering design optimization problems, primarily low-fidelity problems so that we are able to statistically evaluate the performance of BO methods with various covariance functions. In this paper, we performed the study using a set of subsonic airfoil optimization cases as benchmark problems. Expected hypervolume improvement was used as the acquisition function to enrich the experimental design. Results show that the choice of the covariance function give a notable impact on the performance of multi-objective BO. In this regard, Kriging models with Matern-3/2 is the most robust method in terms of the diversity and convergence to the Pareto front that can handle problems with various complexities.Natural Environment Research Council (NERC

    Comparative study of the degree of patient satisfaction in intermittent catheterization with Lofric and polyvinyl chloride catheters

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    Actas Urol Esp. 2001 Nov-Dec;25(10):725-30. [Comparative study of the degree of patient satisfaction in intermittent catheterization with Lofric and polyvinyl chloride catheters]. [Article in Spanish] López Pereira P, Martínez Urrutia MJ, Lobato L, Rivas S, Jaureguizar Monereo E. SourceUnidad de Urología Infantil, Hospital Universitario La Paz, Madrid. Abstract PURPOSE: To assess the grade of satisfaction in children on intermittent catheterization with the use of LoFric and PVC conventional catheters. MATERIAL AND METHODS: A total of 40 p with experience in CIC were included in this study. An anonymous questionnaire was sent to all patients after 2-months using the LoFric catheter. Patients were divided in 3 groups (bladder augmentation, artificial sphincter, Mitrofanoff) because of major differences in CIC discomfort between these groups. RESULTS: The questionnaire was completed by 87.5% of the patients (35 p). In 86% (30 p) LoFric catheter training was easy or very easy but in 14% (5 p) it was difficult. Four patients had some difficulty during conventional catheter insertion, in 3 (75%) the difficulty disappeared with the use of LoFric catheter. Of the 51% (18 p) who reported some discomfort during the insertion of conventional catheter, 72% said it was eliminated when the LoFric catheter was used. Of 6 p with some discomfort when removing the conventional catheter, 5 (83%) said it disappeared with the new catheter. Th LoFric catheter was favored by 70% of patients because it reduced the discomfort caused by conventional catheters, bladder insertion was easier and smoother, and gel lubrication was not needed. The 17% of patients reported some difficulty dealing with this slippery catheter. CONCLUSIONS: The use of the LoFric catheter could be justified in patients who report with conventional catheters have some discomfort. It can also be recommended in patients with artificial sphincter, bladder augmentation and Mitrofanoff procedure, in whom any complication related to CIC would have serious consequences

    Stellar equilibrium configurations of white dwarfs in the f(R,T)f(R,T) gravity

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    In this work we investigate the equilibrium configurations of white dwarfs in a modified gravity theory, na\-mely, f(R,T)f(R,T) gravity, for which RR and TT stand for the Ricci scalar and trace of the energy-momentum tensor, respectively. Considering the functional form f(R,T)=R+2λTf(R,T)=R+2\lambda T, with λ\lambda being a constant, we obtain the hydrostatic equilibrium equation for the theory. Some physical properties of white dwarfs, such as: mass, radius, pressure and energy density, as well as their dependence on the parameter λ\lambda are derived. More massive and larger white dwarfs are found for negative values of λ\lambda when it decreases. The equilibrium configurations predict a maximum mass limit for white dwarfs slightly above the Chandrasekhar limit, with larger radii and lower central densities when compared to standard gravity outcomes. The most important effect of f(R,T)f(R,T) theory for massive white dwarfs is the increase of the radius in comparison with GR and also f(R)f(R) results. By comparing our results with some observational data of massive white dwarfs we also find a lower limit for λ\lambda, namely, λ>3×104\lambda >- 3\times 10^{-4}.Comment: To be published in EPJ

    Asthma and COPD "Overlap": a Treatable Trait or Common Several Treatable-Traits?

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    In the last years, disease classification of chronic respiratory diseases (CRD) has been vivaciously discussed and new concepts have been introduced, namely asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO). Controversially the GOLD consensus document of 2020 considered that we should no longer refer to ACO, as they constitute two different diseases that may share some common traits and clinical features. The treatable traits approach has numerous strengths that are applicable to several levels of health care. In this paper we review the application of the treatable traits to CRD and describe in detail the ones already identified in patients with asthma and COPD. Treatable traits in CRD can be divided in pulmonary, extra-pulmonary and behavior/lifestyle risk factors. Patients with both asthma and COPD patients have clearly recognized treatable traits in all these subtopics but it is notorious the severe and frequent exacerbations, the associated cardiovascular disease and the low health related quality of life and productivity of these patients.info:eu-repo/semantics/publishedVersio

    Pandemic influenza control in Europe and the constraints resulting from incoherent public health laws

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    © 2010 Martin et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: With the emergence of influenza H1N1v the world is facing its first 21st century global pandemic. Severe Acute Respiratory Syndrome (SARS) and avian influenza H5N1 prompted development of pandemic preparedness plans. National systems of public health law are essential for public health stewardship and for the implementation of public health policy[1]. International coherence will contribute to effective regional and global responses. However little research has been undertaken on how law works as a tool for disease control in Europe. With co-funding from the European Union, we investigated the extent to which laws across Europe support or constrain pandemic preparedness planning, and whether national differences are likely to constrain control efforts. Methods: We undertook a survey of national public health laws across 32 European states using a questionnaire designed around a disease scenario based on pandemic influenza. Questionnaire results were reviewed in workshops, analysing how differences between national laws might support or hinder regional responses to pandemic influenza. Respondents examined the impact of national laws on the movements of information, goods, services and people across borders in a time of pandemic, the capacity for surveillance, case detection, case management and community control, the deployment of strategies of prevention, containment, mitigation and recovery and the identification of commonalities and disconnects across states. Results: Results of this study show differences across Europe in the extent to which national pandemic policy and pandemic plans have been integrated with public health laws. We found significant differences in legislation and in the legitimacy of strategic plans. States differ in the range and the nature of intervention measures authorized by law, the extent to which borders could be closed to movement of persons and goods during a pandemic, and access to healthcare of non-resident persons. Some states propose use of emergency powers that might potentially override human rights protections while other states propose to limit interventions to those authorized by public health laws. Conclusion: These differences could create problems for European strategies if an evolving influenza pandemic results in more serious public health challenges or, indeed, if a novel disease other than influenza emerges with pandemic potential. There is insufficient understanding across Europe of the role and importance of law in pandemic planning. States need to build capacity in public health law to support disease prevention and control policies. Our research suggests that states would welcome further guidance from the EU on management of a pandemic, and guidance to assist in greater commonality of legal approaches across states.Peer reviewe

    Different kidney function trajectory patterns before dialysis in elderly patients: clinical implications and outcomes

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    Background. Identifying trajectories of kidney disease progression in chronic kidney disease (CKD) patients may help to deliver better care. We aimed to identify and characterize trajectories of renal function decline in CKD patients and to investigate their association with mortality after dialysis.Methods. This retrospective cohort study included 378 CKD patients who initiated dialysis (aged 65 years and over) between 2009 and 2016. Were considered mixed models using linear quadratic and cubic models to define the trajectories, and we used probabilistic clustering procedures. Patient characteristics and care practices at and before dialysis were examined by multivariable multinomial logistic regression. The association of these trajectories with mortality after dialysis was examined using Cox models.Results. Four distinct groups of eGFR trajectories decline before dialysis were identified: slower decline (18.3%), gradual decline (18.3%), early rapid decline (41.2%), and rapid decline (22.2%). Patients with rapid eGFR decline were more likely to have diabetes, more cognitive impairment, to have been hospitalized before dialysis, and were less likely to have received pre-dialysis care compared to the patients with a slower decline. They had a higher risk of death within the first and fourth year after dialysis initiation, and after being more than 4 years in dialysis.Conclusions. There are different patterns of eGFR trajectories before dialysis initiation in the elderly, that may help to identify those who are more likely to experience an accelerated decline in kidney function, with impact on pre ESKD care and in the mortality risk after dialysis
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