458 research outputs found
LOWER ORDER PERTURBATION AND GLOBAL ANALYTIC VECTORS FOR A CLASS OF GLOBALLY ANALYTIC HYPOELLIPTIC OPERATORS
No full textIn this work we return to the class of globally analytic hypoelliptic Hormander's operators defined on the N-dimensional torus introduced by Cordaro and Himonas and prove that if P is any operator in this class, then a perturbation of P by an analytic pseudodifferential operator with degree smaller than the subelliptic index of P remains globally analytic hypoelliptic. We also study the Gevrey regularity of the Gevrey vectors for such a class and at the end we also show that Cordaro and Himonas's result can be extended to a similar class of operators now defined in a product of compact Lie group by a compact manifold
On global analytic and Gevrey hypoellipticity on the torus and the M??tivier inequality
No full textWe obtain a global version in the N-dimensional torus of the Metivier inequality for analytic and Gevrey hypoellipticity, and based on it we introduce a class of globally analytic hypoelliptic operators which remain so after suitable lower order perturbations. We also introduce a new class of analytic (pseudodifferential) operators on the torus whose calculus allows us to study the corresponding perturbation problem in a far more general context
Local solvability for a class of evolution equations
No full textMotivated by the celebrated example of Y. Kannai of a linear partial differential operator which is hypoelliptic but not locally solvable, we consider it class of evolution operators with real-analytic coefficients and study their local solvability both in L(2) and in the weak sense. In order to do so we are led to propose a generalization of the Nirenberg-Treves condition (psi) which is suitable to our study. (C) 2009 Published by Elsevier Inc.CNPqConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fapes
The relationship between nostalgia, social exclusion, and empathy
No full textAs a positive, social emotion, nostalgia has the potential to reduce the negative impact of social exclusion on empathy. I ran a series of experiments in order to establish the relationship between nostalgia, social exclusion, and empathy. In Studies 1 and 2, participants were instructed to recall either a nostalgic or ordinary autobiographical experience and then read an essay ostensibly written by another participant describing a physically painful ordeal. Afterwards, the participants were asked to report the level of empathy that they felt for the person who wrote the essay. Participants who had previously recalled a nostalgic event reported significantly higher levels of empathy than those who had recalled an ordinary event. In Studies 3 and 4, participants were given randomly assigned future alone, future belonging, or control feedback. Participants who were given future alone (compared to future belonging or control) feedback reported significantly higher levels of nostalgia. Study 5 examined nostalgia’s ability to directly counteract social threats. Individuals who were exposed to a future alone (compared to future belonging) feedback reported lower levels of empathy when they were instructed to recall an ordinary autobiographical experience. However, the future alone manipulation had no significant effect on empathy when participants recalled a nostalgic experience. The results suggest that nostalgia may function as an adaptive reaction to social exclusion, and can prevent people from becoming emotionally numb after being exclude
Periodontitis and platelet count: A new potential link with cardiovascular and other systemic inflammatory diseases
No full textAim: As an infection-driven inflammatory disease, periodontitis could lead to a reactive increase in platelet count. This mechanism could partially mediate the well-documented association between periodontitis and atherosclerotic cardiovascular disease. The aim of this cross-sectional study was to test the presence of an association between periodontitis and platelet count in a representative sample of the South Korea population. Materials and methods: A total of 5,197 subjects representative of 34.9 million of adults were examined. Multivariate regression analyses were applied controlling for age, gender, smoking status, educational level, body mass index, alcoholism, diabetes and hypertension status, vitamin D serum levels and total cholesterol, triglycerides, HDL and LDL blood levels. Results: Compared to the non-severe periodontitis group, subjects with severe periodontitis (CPI = 4) displayed 13,048.93 more platelets for μl of blood (95% CI: 3,296.26–22,801.61, p = 0.009) in the fully-adjusted model. The association between severe periodontitis and platelet count has shown to be highlighted in subjects aged more than 60 years, females, non-smokers and with normal HDL blood levels. A systemic inflammatory biomarker (white blood cell count) explained the 19.25% of this association. Conclusions: Within the limitations of this study, periodontitis—especially severe—is independently associated with a considerable increase in platelet count which is explained, at least in part, by an increase in the systemic inflammation
Non-Semisimple Gaugings of D=5 N=8 Supergravity and FDA.s
No full textWe reformulate maximal D = 5 supergravity in the consistent approach uniquely based on free differential algebras and the solution of their Bianchi identities (i.e. the rheonomic method). In this approach the Lagrangian is unnecessary since the field equations follow from closure of the supersymmetry algebra. This enables us to explicitly construct the non-compact gaugings corresponding to the non-semisimple algebras CSO(p, q, r), irrespectively of the existence of a Lagrangian. The use of free differential algebras is essential to clarify, within a cohomological set-up, the dualization mechanism between 1-and 2-forms. Our theories contain 12-r self-dual 2-forms and 15+r gauge vectors, r of which are Abelian and neutral. These theories, whose existence is proved and their supersymmetry algebra constructed hereby, have potentially interesting properties in relation to domain wall solutions and the trapping of gravity.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Rialzo del pavimento del seno mascellare per l’inserimento degli impianti ITI senza prelievo di osso extraorale: nostra esperienza
No full textUltrasonographic evaluation of the effects of orthodontic or functional orthopaedic treatment on masseter muscles: A systematic review and meta-analysis
No full textObjectives: This review investigated the effects of orthodontic or functional orthopedic therapy on masseter muscle thickness through the use of ultrasonography (US) in growing subjects when compared with untreated subjects. Materials and Methods: This review systematically assessed studies that investigated growing subjects undergoing orthopedic therapy for the correction of malocclusion of vertical, sagittal and transversal plane. Electronic databases (CENTRAL, MEDLINE-PubMed, Scopus and Web of Science) were searched up to February 2019, including available RCTs and CCTs, without language restrictions. The primary outcome was the effect of orthopedic or functional treatment on masseter muscle thickness. The risk of bias of included studies was assessed through the Newcastle-Ottawa quality assessment scale with the aim of defining their methodological quality. A random-effects meta-analysis analyzing mean differences with 95% confidence intervals was used for quantitative analysis. Results: The search retrieved 749 titles, but the studies selection resulted in a final sample of 5 CCTs. The studies retrieved data from 233 children (age range: 5-22 years) and were conducted at university dental clinics. Children were treated for Class II malocclusion, increased vertical dimension or lateral cross-bite variably with rapid or slow maxillary expansion, twin block, bite block, mandibular activators, quad helix, alone or in combination. Risk of bias was assessed as medium for three studies, low for one and high for another. The meta-analysis determined that at the end of orthopedic or functional treatment masseter muscle thickness, measured through the use of US, is significantly reduced (MD -0.79 mm; 95% CI -1.28 to -0.31). The reduction in muscle thickness, therefore, could be considered an indicator for the evaluation of the success of therapy with orthodontic appliances. Conclusions: Although the meta-analysis revealed that US could be considered a less invasive and effective method to evaluate the masseter muscle thickness, single-blinded RCTs, are required to confirm US reliability in this field of application. This review was registered on PROSPERO with the following registration number: CRD42018068402
Terapia ortopedica funzionale mediante Fränkel nella Classe III: risultati ortopedici
No full textNot Availabl
Periodontitis and platelet count: A new potential link with cardiovascular and other systemic inflammatory diseases
No full textAim: As an infection-driven inflammatory disease, periodontitis could lead to a reactive increase in platelet count. This mechanism could partially mediate the well-documented association between periodontitis and atherosclerotic cardiovascular disease. The aim of this cross-sectional study was to test the presence of an association between periodontitis and platelet count in a representative sample of the South Korea population. Materials and methods: A total of 5,197 subjects representative of 34.9 million of adults were examined. Multivariate regression analyses were applied controlling for age, gender, smoking status, educational level, body mass index, alcoholism, diabetes and hypertension status, vitamin D serum levels and total cholesterol, triglycerides, HDL and LDL blood levels. Results: Compared to the non-severe periodontitis group, subjects with severe periodontitis (CPI = 4) displayed 13,048.93 more platelets for μl of blood (95% CI: 3,296.26–22,801.61, p = 0.009) in the fully-adjusted model. The association between severe periodontitis and platelet count has shown to be highlighted in subjects aged more than 60 years, females, non-smokers and with normal HDL blood levels. A systemic inflammatory biomarker (white blood cell count) explained the 19.25% of this association. Conclusions: Within the limitations of this study, periodontitis—especially severe—is independently associated with a considerable increase in platelet count which is explained, at least in part, by an increase in the systemic inflammation
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