320 research outputs found
Economic factors affecting obesity: an application in Italy
No full textThe World Health Organization has stated that obesity is spreading around the world like a “global epidemic”. In 2004 the percentage of obese people in the Italian population was 9%, but the trend s increasing in recent years. Focusing on this country, the purpose of the paper is to analyze the socio-economic variables affecting obesity by means of a survey conducted in a consumer sample. Our analysis is based on a survey conducted in Italy, and the sample was composed of 999 consumers. We used a binary logit model and the dependent variable is body mass index (BMI), expressed in a dichotomic way (seriously overweight and obese, value 1, and normal weight, value 0). The results show that the condition of the seriously overweight and obese increases with age, especially in people over 65 of age. Also gender is correlated with the pathology: being seriously overweight and obese is far more likely for men than for women. An inverse relation was shown between obesity and education, and between obesity and the level of food knowledge. The results highlight that disadvantaged social categories are more susceptible to the problem of overweight and obesity. A policy implication of the analysis, to limit the spread of obesity, could lie in programs aimed at improving health and food awareness and focused on these minority groups.economics of obesity, BMI and consumer, logit model, Food Consumption/Nutrition/Food Safety, Health Economics and Policy,
Author response
No full textDetecting pathogens and mounting immune responses upon infection is crucial for animal health. However, these responses come at a high metabolic price (McKean and Lazzaro, 2011, Kominsky et al., 2010), and avoiding pathogens before infection may be advantageous. The bacterial endotoxins lipopolysaccharides (LPS) are important immune system infection cues (Abbas et al., 2014), but it remains unknown whether animals possess sensory mechanisms to detect them prior to infection. Here we show that Drosophila melanogaster display strong aversive responses to LPS and that gustatory neurons expressing Gr66a bitter receptors mediate avoidance of LPS in feeding and egg laying assays. We found the expression of the chemosensory cation channel dTRPA1 in these cells to be necessary and sufficient for LPS avoidance. Furthermore, LPS stimulates Drosophila neurons in a TRPA1-dependent manner and activates exogenous dTRPA1 channels in human cells. Our findings demonstrate that flies detect bacterial endotoxins via a gustatory pathway through TRPA1 activation as conserved molecular mechanism.sponsorship: Vlaams Instituut voor Biotechnologie Alessia Soldano Luis Franco Guangda Liu Natalia Mora Emre Yaksi Bassem A Hassanr Fonds Wetenschappelijk Onderzoek G.0702.12 Alessia Soldano Yeranddy A Alpizar Brett Boonen Alejandro Lopez-Requena Natalia Mora Thomas Voets Rudi Vennekens Bassem A Hassan Karel Talaverar Fonds Wetenschappelijk Onderzoek G.0077.15 Alessia Soldano Yeranddy A Alpizar Brett Boonen Alejandro Lopez-Requena Natalia Mora Thomas Voets Rudi Vennekens Bassem A Hassan Karel Talaverar Fonds Wetenschappelijk Onderzoek G.0680.10 Alessia Soldano Yeranddy A Alpizar Brett Boonen Alejandro Lopez-Requena Natalia Mora Thomas Voets Rudi Vennekens Bassem A Hassan Karel Talaverar Fonds Wetenschappelijk Onderzoek G.0681.10 Alessia Soldano Yeranddy A Alpizar Brett Boonen Alejandro Lopez-Requena Natalia Mora Thomas Voets Rudi Vennekens Bassem A Hassan Karel Talaverar Fonds Wetenschappelijk Onderzoek G.0503.12 Alessia Soldano Yeranddy A Alpizar Brett Boonen Alejandro Lopez-Requena Natalia Mora Thomas Voets Rudi Vennekens Bassem A Hassan Karel Talaverar Fonds Wetenschappelijk Onderzoek G.0654.15 Alessia Soldano Yeranddy A Alpizar Brett Boonen Alejandro Lopez-Requena Natalia Mora Thomas Voets Rudi Vennekens Bassem A Hassan Karel Talaverar Fonds Wetenschappelijk Onderzoek G.0761.10N Alessia Soldano Yeranddy A Alpizar Brett Boonen Alejandro Lopez-Requena Natalia Mora Thomas Voets Rudi Vennekens Bassem A Hassan Karel Talaverar Fonds Wetenschappelijk Onderzoek G.0596.12 Alessia Soldano Yeranddy A Alpizar Brett Boonen Alejandro Lopez-Requena Natalia Mora Thomas Voets Rudi Vennekens Bassem A Hassan Karel Talaverar Fonds Wetenschappelijk Onderzoek G.0565.07 Alessia Soldano Yeranddy A Alpizar Brett Boonen Alejandro Lopez-Requena Natalia Mora Thomas Voets Rudi Vennekens Bassem A Hassan Karel Talaverar KU Leuven GOA/14/011 Alessia Soldano Yeranddy A Alpizar Brett Boonen Luis Franco Alejandro Lopez-Requena Guangda Liu Natalia Mora Emre Yaksi Thomas Voets Rudi Vennekens Bassem A Hassan Karel Talaverar European Commission IUAP P7/13 Alessia Soldano Yeranddy A Alpizar Brett Boonen Luis Franco Alejandro Lopez-Requena Guangda Liu Natalia Mora Emre Yaksi Thomas Voets Rudi Vennekensr KU Leuven OT/12/091 Alessia Soldano Yeranddy A Alpizar Brett Boonen Luis Franco Alejandro Lopez-Requena Guangda Liu Natalia Mora Emre Yaksi Thomas Voets Rudi Vennekens Bassem A Hassan Karel Talaverar KU Leuven PF-TRPLe Alessia Soldano Yeranddy A Alpizar Brett Boonen Luis Franco Alejandro Lopez-Requena Guangda Liu Natalia Mora Emre Yaksi Thomas Voets Rudi Vennekens Bassem A Hassan Karel Talavera (Vlaams Instituut voor Biotechnologie, Fonds Wetenschappelijk Onderzoek|G.0702.12, Fonds Wetenschappelijk Onderzoek|G.0077.15, Fonds Wetenschappelijk Onderzoek|G.0680.10, Fonds Wetenschappelijk Onderzoek|G.0681.10, Fonds Wetenschappelijk Onderzoek|G.0503.12, Fonds Wetenschappelijk Onderzoek|G.0654.15, Fonds Wetenschappelijk Onderzoek|G.0761.10N, Fonds Wetenschappelijk Onderzoek|G.0596.12, KU Leuven|GOA/14/011, KU Leuven|OT/12/091, European Commission|IUAP P7/13, KU Leuven PF-TRPLe)status: Publishe
Efficient equilibrium-based stress recovery for isogeometric laminated curved structures
No full textThis work extends the stress recovery for laminated composite solid plates, proposed in [1,2], to curved structures. Based on 3D Isogeometric Analysis (IGA) computations and equilibrium, this procedure uses a single element through the thickness in combination with a calibrated layer-by-layer integration rule or a homogenized approach, allowing for an inexpensive and accurate approximation in terms of in-plane stresses (and their derivatives), while through-the-thickness stress components are poorly approximated. Relying on the highorder continuity properties of IGA shape functions, an accurate out-of-plane stress state can also be recovered by means of direct integration of the equilibrium equations in strong form. The a posteriori step application, which is straightforward in the context of solid plates, is not trivial in the case of curved geometries. In fact, the notion of in-plane and out-of-plane directions is not clear when modeling this kind of structures in the global reference system, while adopting curvilinear coordinates to express the equilibrium gives rise to additional coupled terms that require an iterative process to resolve the balance of momentum equation. Therefore, we propose to apply the recovery locally, which, despite leading to more elaborated stress derivative terms because of the increasing geometry complexity, still allows for a direct reconstruction as the resolvent system is uncoupled. Several numerical results show the good performance of this approach particularly for composite stacks with significant radius-to-thickness ratio and number of plies.MN
A rigorous and efficient explicit algorithm for irreversibility enforcement in phase-field finite element and isogeometric modeling of brittle crack propagation
No full textIn the present work, a computationally efficient and explicit algorithm for the rigorous enforcement of the irreversibility
constraint in the phase-field modeling of brittle fracture is presented. The proposed approach is staggered and relies on the
alternate minimization of the total energy functional. The phase-field evolution turns out to be governed by a complementarity
boundary-value problem, where the complementarity stems from the irreversibility, while the boundary-value problem is
originated by the presence of the gradient term in the phase-field functional. Several different techniques have been proposed in
the literature to account for damage irreversibility in a computationally effective way. Following a similar approach proposed
in the past for a gradient-plasticity problem, a particularly simple and effective solution strategy based on the Projected
Successive Over-Relaxation (PSOR) method for constrained optimization, where an iterative explicit scheme is used for the
solution of symmetric linear complementarity problems, is presented. Even though the proposed method is restricted to linear
complementarity problems, it can be applied to the numerical simulation of a wide range of problems discussed in the literature.
The performance of the suggested solution algorithm on a number of test cases is compared with that of a recently proposed
penalty approach for the approximated enforcement of irreversibility
Higher order phase-field modeling of brittle fracture via isogeometric analysis
No full textThe evolution of brittle fracture in a material can be conveniently investigated by means of the phase-field technique introducing a smooth crack density functional. Following Borden et al. (2014), two distinct types of phase-field functional are considered: (i) a second-order model and (ii) a fourth-order one. The latter approach involves the bi-Laplacian of the phase field and therefore the resulting Galerkin form requires continuously differentiable basis functions: a condition we easily fulfill via Isogeometric Analysis. In this work, we provide an extensive comparison of the considered formulations performing several tests that progressively increase the complexity of the crack patterns. To measure the fracture length necessary in our accuracy evaluations, we propose an image-based algorithm that features an automatic skeletonization technique able to track complex fracture patterns. In all numerical results, damage irreversibility is handled in a straightforward and rigorous manner using the Projected Successive Over-Relaxation algorithm that is suitable to be adopted for both phase-field formulations since it can be used in combination with higher continuity isogeometric discretizations. Based on our results, the fourth-order approach provides higher rates of convergence and a greater accuracy. Moreover, we observe that fourth- and second-order models exhibit a comparable accuracy when the former methods employ a mesh-size approximately two times larger, entailing a substantial reduction of the computational effort
Investigation of microscale brittle fracture opening in diamond with olivine inclusion using XFEM and cohesive zone modeling
No full textInclusions trapped in diamonds are a fundamental source of information to probe the Earth's interior, provided that the pressure conditions at which the diamond grew are correctly determined. This study explores the traditional assumptions in geothermobarometry for olivine-in-diamond host-inclusion systems by employing extended finite element methods (XFEM) and cohesive zone models (CZM) to quantify the contributions of brittle fractures to the relaxation of the residual stress of inclusions. Our analysis was performed assuming that the host-inclusion system does not contain fluids and that the unfractured minerals are elastically isotropic. Our models show that the damage initiation is solely dependent on the shape of the inclusion and on the fracture strength of the diamond host, while the fracture nucleation is influenced by both the size of the inclusion and the toughness of the diamond. Our findings indicate that, in dry systems, the amount of relaxation of residual stress of the inclusion due to the opening of brittle fractures is much lower than that due to the elastic interaction between the host and the inclusion. Moreover, the pressure release due to fractures is not substantially affected by the shape of the inclusion. We also show that the total relaxation of the residual pressure due to the combined effect of the elastic interaction and the brittle deformation is lower than what is observed in natural samples, even when assuming fracture strength and toughness lower than those reported from experiments on single crystals of diamond. Such discrepancies suggest that in natural olivine-diamond systems additional mechanisms such as viscous or plastic deformation and/or the presence of preexisting defects and fluids in the host might play a relevant role in the relaxation of the residual stress. These findings underscore the need for advanced numerical tools that consider the complex interplay of the geometry of the host-inclusion system, the fracture properties, and the presence of fluids and defects in order to build more accurate models to constrain the geological history of diamonds
Social Network to analyse the relationship between ‘victim-author’ and ‘motivation’ of violence against women in Italy.
No full textThe paper aims to analyse the phenomenon of Violence against women in the Italian context during 2020. It proposes to study the relationship between ‘victim-author’ and ‘motivation’ in femicides committed in domestic environment. By means of the properties of the Social Network Analysis on bimodal data, the study detected main actors and motivations that generated the homicides with female victims. At the same time, the structural relationships allowed to investigate the existence of motivations that better characterized the action of the various actors. The bipartite graph visualization and centrality scores calculated have demonstrated the effectiveness of the methodology for the pursued objectives
Louis-Philippe Dalembert, «vagabond jusqu’au bout de la fatigue»
No full textThe Haitian novelist and poet Louis-Philippe Dalembert (Port-au-Prince, 1962) has developed in his works of fiction the concept of vagabondage as a literary projection of his biographical wandering through multiple spaces. The aim of this essay is to study the presence of vagabondage and its distinctive features in those novels written by Dalembert that reflect the writer’s perpetual motion: Le Crayon du bon Dieu n’a pas de gomme (1996), L’Autre face de la mer (1998), L’Île du bout des rêves (2003), Les dieux voyagent la nuit (2006). The main characters are constantly moving, they are cosmopolitan wanderers who belong to many places at the same time, just like Dalembert himself. By analyzing the representation of movement in these fictions, we will show that the notion of vagabondage is depicted by the author as a positive and meaningful opportunity for the vagabond who travels across countries, languages and cultures
- …
