Minimality via second variation for a nonlocal isoperimetric problem

We discuss the local minimality of certain configurations for a nonlocal isoperimetric problem used to model microphase separation in diblock copolymer melts. We show that critical configurations with positive second variation are local minimizers of the nonlocal area functional and, in fact, satisfy a quantitative isoperimetric inequality with respect to sets that are $L^1$-close. The link with local minimizers for the diffuse-interface Ohta-Kawasaki energy is also discussed. As a byproduct of the quantitative estimate, we get new results concerning periodic local minimizers of the area functional and a proof, via second variation, of the sharp quantitative isoperimetric inequality in the standard Euclidean case. As a further application, we address the global and local minimality of certain lamellar configurations.Comment: 35 page

A variational problem for multifunctions with interaction between leaves

We discuss a variational problem defined on couples of functions that are constrained to take values into the 2-dimensional unit sphere. The energy functional contains, besides standard Dirichlet energies, a non-local interaction term that depends on the distance between the gradients of the two functions. Different gradients are preferred or penalized in this model, in dependence of the sign of the interaction term. In this paper we study the lower semicontinuity and the coercivity of the energy and we find an explicit representation formula for the relaxed energy. Moreover, we discuss the behavior of the energy in the case when we consider multifunctions with two leaves rather than couples of functions

Curvature-dependent energies: The elastic case

We continue our analysis on functionals depending on the curvature of graphs of curves in high codimension Euclidean space. We deal with the “elastic” case, corresponding to a superlinear dependence on the pointwise curvature.We introduce the corresponding relaxed energy functional and prove an explicit representation formula. Different phenomena w.r.t. the “plastic” case, i.e. to the relaxation of the total curvature functional, are observed. A p-curvature functional is well-defined on continuous curves with finite relaxed energy, and the relaxed energy is given by the length plus the p-curvature. The wider class of graphs of one-dimensional BV-functions is treated

Stability of Lamellar Configurations in a Nonlocal Sharp Interface Model

Equilibrium models based on a free energy functional deserve special interest in recent investigations, as their critical points exhibit various pattern structures. These systems are characterized by the presence of coexisting phases, whose distribution results from the competition between short and long-range interactions. This article deals with an energy-driven sharp interface model with long-range interaction being governed by a screened Coulomb kernel. We investigate a number of criteria for the stability of lamellar configurations, as they are indeed strict local minimizers. We also give a sufficient condition to ensure a nontrivial periodic 2D minimal energy configuration

GEN-O-MA project: an Italian network studying clinical course and pathogenic pathways of moyamoya disease—study protocol and preliminary results

Background: GENetics of mOyaMoyA (GEN-O-MA) project is a multicenter observational study implemented in Italy aimed at creating a network of centers involved in moyamoya angiopathy (MA) care and research and at collecting a large series and bio-repository of MA patients, finally aimed at describing the disease phenotype and clinical course as well as at identifying biological or cellular markers for disease progression. The present paper resumes the most important study methodological issues and preliminary results. Methods: Nineteen centers are participating to the study. Patients with both bilateral and unilateral radiologically defined MA are included in the study. For each patient, detailed demographic and clinical as well as neuroimaging data are being collected. When available, biological samples (blood, DNA, CSF, middle cerebral artery samples) are being also collected for biological and cellular studies. Results: Ninety-eight patients (age of onset mean ± SD 35.5 ± 19.6 years; 68.4% females) have been collected so far. 65.3% of patients presented ischemic (50%) and haemorrhagic (15.3%) stroke. A higher female predominance concomitantly with a similar age of onset and clinical features to what was reported in previous studies on Western patients has been confirmed. Conclusion: An accurate and detailed clinical and neuroimaging classification represents the best strategy to provide the characterization of the disease phenotype and clinical course. The collection of a large number of biological samples will permit the identification of biological markers and genetic factors associated with the disease susceptibility in Italy

Análise da prevalência e características do burnout em profissionais da saúde que atuaram em hospitais de referência para COVID-19 no ES

Introdução: A doença viral denominada COVID-19, causada pelo SARS-CoV-2, iniciou seu curso infeccioso pela China em dezembro de 2019 e levou a OMS a declarar estado de pandemia global em 30 de janeiro de 2020, afetando drasticamente a saúde física e mental de uma parcela considerável da população mundial. Paralelo a esse quadro, a síndrome de burnout tem uma alta incidência entre os profissionais da área da saúde, principalmente frente a condições adversas de trabalho, dentre as quais podemos destacar uma recém-descoberta pandemia viral com tamanho poder de infectividade como o SARS-CoV-2. Objetivo: Analisar as características e prevalência do burnout presente em profissionais em área de tratamento referência COVID-19, e propor ideias de enfrentamento. Método: A pesquisa é composta de duas etapas: 1- avaliação inicial, e 2- avaliação final. Um questionário sistematizado, com 40 questões, foi aplicado aos profissionais da área. Resultado: Dentre os 96 entrevistados na avaliação inicial, segundo os preditores indicados pelo Grupo de Estudo e Pesquisa sobre Stress e Síndrome de Burnout, apenas 32 médicos pontuaram dentro dos níveis que sugerem burnout (Baixo, Médio e Alto), sendo que o nível “Médio” das três dimensões analisadas (Exaustão Emocional, Despersonalização, Realização Pessoal) foi o mais prevalente. Conclusão: Diante desse contexto, a caracterização da síndrome de burnout nos profissionais da saúde é de fundamental importância para o delineamento de estratégias de promoção de saúde mental e qualidade de vida destes profissionais, submetidos à alta carga de trabalho e a diversos sentimentos negativos observados

Measurement of the b-hadron production cross section using decays to D*+ μ − X final states in pp collisions at √s = 7 TeV with the ATLAS detector

The b-hadron production cross section is measured with the ATLAS detector in pp collisions at √s = 7 TeV, using 3.3 pb−1 of integrated luminosity, collected during the 2010 LHC run. The b-hadrons are selected by partially reconstructing D*+μ−X final states. Differential cross sections are measured as functions of the transverse momentum and pseudorapidity. The measured production cross section for a b-hadron with pT > 9 GeV and |η| < 2.5 is 32.7±0.8(stat.)+4.5−6.8(syst.) μb, higher than the next-to-leadingorder QCD predictions but consistent within the experimental and theoretical uncertainties

ATLAS search for new phenomena in dijet mass and angular distributions using pp collisions at s\sqrt{s}=7 TeV

Mass and angular distributions of dijets produced in LHC proton-proton collisions at a centre-of-mass energy $\sqrt{s}$=7 TeV have been studied with the ATLAS detector using the full 2011 data set with an integrated luminosity of 4.8/fb. Dijet masses up to 4.0 TeV have been probed. No resonance-like features have been observed in the dijet mass spectrum, and all angular distributions are consistent with the predictions of QCD. Exclusion limits on six hypotheses of new phenomena have been set at 95% CL in terms of mass or energy scale, as appropriate. These hypotheses include excited quarks below 2.83 TeV, colour octet scalars below 1.86 TeV, heavy W bosons below 1.68 TeV, string resonances below 3.61 TeV, quantum black holes with six extra space-time dimensions for quantum gravity scales below 4.11 TeV, and quark contact interactions below a compositeness scale of 7.6 TeV in a destructive interference scenario.publishedVersio

Conceptual Design of a Soft X‐ray SASE‐FEL Source

FELs based on SASE are believed to be powerful tools to explore the frontiers of basic sciences, from physics to chemistry to biology. Intense R&D programs have started in the USA and Europe in order to understand the SASE physics and to prove the feasibility of these sources. The allocation of considerable resources in the Italian National Research Plan (PNR) brought about the formation of a CNR‐ENEA‐INFN‐University of Roma "Tor Vergata" study group. A conceptual design study has been developed and possible schemes for linac sources have been investigated, bringing to the SPARX proposal. We report in this paper the results of a preliminary start to end simulation concerning one option we are considering based on an S‐band normal conducting linac with high brightness photoinjector integrated in a RF compressor