University of Coimbra

About: University of Coimbra is a education organization based out in Coimbra, Portugal. It is known for research contribution in the topics: Population & Context (language use). The organization has 14318 authors who have published 43067 publications receiving 994733 citations. The organization is also known as: UC & Universidade dos Estudos Gerais.

Lifts of Convex Sets and Cone Factorizations

Abstract: In this paper, we address the basic geometric question of when a given convex set is the image under a linear map of an affine slice of a given closed convex cone. Such a representation or lift of the convex set is especially useful if the cone admits an efficient algorithm for linear optimization over its affine slices. We show that the existence of a lift of a convex set to a cone is equivalent to the existence of a factorization of an operator associated to the set and its polar via elements in the cone and its dual. This generalizes a theorem of Yannakakis that established a connection between polyhedral lifts of a polytope and nonnegative factorizations of its slack matrix. Symmetric lifts of convex sets can also be characterized similarly. When the cones live in a family, our results lead to the definition of the rank of a convex set with respect to this family. We present results about this rank in the context of cones of positive semidefinite matrices. Our methods provide new tools for understanding cone lifts of convex sets.

Social determinants of mental health: A review of the evidence

Abstract: Background and Objectives: The aim of this study is to present a non-systematic narrative review of the published evidence on the association between mental health and sociodemographic and economic factors at individual- and at area-level. Methods: A literature search of PubMed and Web of Science was carried out to identify studies published between 2004 and 2014 on the impact of sociodemographic and economic individual or contextual factors on psychiatric symptoms, mental disorders or suicide. The results and methodological factors were extracted from each study. Results Seventy-eight studies assessed associations between individual-level factors and mental health. The main individual factors shown to have a statistically significant independent association with worse mental health were low income, not living with a partner, lack of social support, female gender, low level of education, low income, low socioeconomic status, unemployment, financial strain, and perceived discrimination. Sixty-nine studies reported associations between area-level factors and mental health, namely neighbourhood socioeconomic conditions, social capital, geographical distribution and built environment, neighbourhood problems and ethnic composition. Conclusions Most of the 150 studies included reported associations between at least one sociodemographic or economic characteristic and mental health outcomes. There was large variability between studies concerning methodology, study populations, variables, and mental illness outcomes, making it difficult to draw more than some general qualitative conclusions. This review highlights the importance of social factors in the initiation and maintenance of mental illness and the need for political action and effective interventions to improve the conditions of everyday life in order to improve population's mental health.

Novel Methods for Pulse Wave Velocity Measurement

Abstract: The great incidence of cardiovascular (CV) diseases in the world spurs the search for new solutions to enable an early detection of pathological processes and provides more precise diagnosis based in multi-parameters assessment. The pulse wave velocity (PWV) is considered one of the most important clinical parameters for evaluate the CV risk, vascular adaptation, and therapeutic efficacy. Several studies were dedicated to find the relationship between PWV measurement and pathological status in different diseases, and proved the relevance of this parameter. The commercial devices dedicate to PWV estimation make a regional assessment (measured between two vessels), however a local measurement is more precise evaluation of artery condition, taking into account the differences in the structure of arteries. Moreover, the current devices present some limitations due to the contact nature. Emerging trends in CV monitoring are moving away from more invasive technologies to non-invasive and non-contact solutions. The great challenge is to explore the new instrumental solutions that allow the PWV assessment with fewer approximations for an accurately evaluation and relatively inexpensive techniques in order to be used in the clinical routine.