Error analysis of a SUPG-stabilized POD-ROM method for convection-diffusion-reaction equations

A reduced order model (ROM) method based on proper orthogonal decomposition (POD) is analyzed for convection-diffusion-reaction equations. The streamline-upwind Petrov--Galerkin (SUPG) stabilization is used in the practically interesting case of dominant convection, both for the full order method (FOM) and the ROM simulations. The asymptotic choice of the stabilization parameter for the SUPG-ROM is done as proposed in the literature. This paper presents a finite element convergence analysis of the SUPG-ROM method for errors in different norms. The constants in the error bounds are uniform with respect to small diffusion coefficients. Numerical studies illustrate the performance of the SUPG-ROM method

Estrutura e interação entre vegetação e ambiente de uma floresta ombrófila densa das terras baixas, Espírito Santo

O objetivo deste trabalho foi conhecer a estrutura e a composição de espécies da comunidade arbustiva-arbórea de um fragmento florestal de uma Floresta Ombrófila Densa das Terras Baixas, bem como verificar a interação da vegetação com as variáveis ambientais. Foram demarcadas 24 parcelas (20 x 20 m), totalizando 0,96 ha, onde foram medidos todos os indivíduos arbustivoarbóreos com diâmetro a altura do peito ≥ 2,5 cm. Além disso, foi calculada a porcentagem de abertura de dossel, por meio de fotografias hemisféricas, e realizada a caracterização química da camada superficial do solo (0 – 5 cm). Os dados foram correlacionados com a densidade absoluta de 25 espécies que possuíam no mínimo 30 indivíduos (obtidas a partir da análise fitossociológica), por meio da Análise de Correspondência Canônica. Foram registrados 4.585 indivíduos e identificadas 379 espécies distribuídas em 195 gêneros e 66 famílias botânicas. A densidade foi de 4.604 ind./ha e a área basal foi 31,88 m²/ha. O índice de Shannon (H’) encontrado para este estudo foi 5,41 e a equabilidade (J) foi 0,83, evidenciando a alta diversidade florística do fragmento e a sua semelhança com áreas bem preservadas da Mata Atlântica. A espécie de maior destaque em Valor de Importância (VI) foi Actinostemon klotzschii (Didr.) Pax, principalmente devido a densidade e frequência. Houve predominância de espécies secundárias tardias (51,9%) e de dispersão zoocórica (72,3%), evidenciando que o fragmento estudado está em bom estado de conservação. A partir da Análise de Correspondência Canônica foi possível comprovar que as variáveis fósforo, magnésio, matéria orgânica, nitrogênio, potássio e abertura de dossel exerceram influência sobre a distribuição das espécies deste fragmento (p<0,05), com destaque para a Xylopia frutescens Aubl. que apresentou elevada correspondência com a porcentagem de abertura de dossel e para as espécies Actinostemon klotzschii (Didr.) Pax, Chrysophyllum lucentifolium Cronquist, Ecclinusa ramiflora Mart., Eugenia platyphylla O.Berg e Rinorea bahiensis (Moric.) Kuntze que se desenvolveram em locais com menor necessidade de nutrientes. Com base no exposto, pode-se concluir que a vegetação possui alta riqueza de espécies e que as variáveis ambientais exercem influência sobre a distribuição das espécies deste fragmento indicando a possibilidade de implantação dessas espécies em locais com maior exposição a luminosidade e baixa fertilidade.The objective of this study was to determine the structure and species composition of shrub-tree community of a forest fragment in Lowlands Rain Forest and verify the interaction of vegetation with environmental variables. 24 plots (20 x 20 m) were marked, totaling 0.96 ha, in which were measured every shrub-trees individuals with diameter at breast height ≥ 2.5 cm. In addition, was calculated the percentage of canopy openness through hemispherical photographs and were performed the chemical characterization of the surface soil layer (0-5 cm). The data were correlated with the absolute density of 25 species that had at least 30 individuals (obtained from the phytosociological analysis) through Canonical Correspondence Analysis. 4,585 individuals were recorded and 379 species were identified, distributed in 195 genera and 66 botanical families. The density was 4,604 ind./ha and basal area was 31.88 m²/ha. The Shannon index (H') found in this study was 5.41 and evenness (J) was 0.83, suggesting the high floristic diversity of the fragment and its similarity with preserved areas of Atlantic Forest. The most remarkable species in Importance Value (IV) was Actinostemon klotzschii (Didr.) Pax, mainly due to density and frequency. Were predominant Late Secondary species (51,9%) and zoochoric dispersion (72.3%), indicating that the studied fragment is in good condition. From the Canonical Correspondence Analysis was possible to prove that the variables phosphorus, magnesium, organic matter, nitrogen, potassium and canopy openness influenced the distribution of species on this fragment (p <0.05), especially for Xylopia frutescens Aubl. that showed high correspondence with the percentage of canopy openness and the Actinostemon klotzschii (Didr.) Pax, Chrysophyllum lucentifolium Cronquist, Ecclinusa ramiflora Mart., Eugenia platyphylla O.Berg and Rinorea bahiensis (Moric.) Kuntze that developed in places with less nutrients. Based on the foregoing, it can be concluded that the vegetation has high species richness and the environmental variables influence on the distribution of species of this fragment indicating the possibility of implantation of these species in places with higher exposure to light and low fertility.CAPE

L’apprenti à l’université dans une logique de construction d’un ethos professionnel. Enquête sur des étudiants apprentis et stagiaires de masters en management du sport

La professionnalisation caractérise l’une des tendances fortes des réformes envisagées ces dernières décennies dans l’enseignement supérieur. Elle s’inscrit dans un double mouvement articulant des logiques disciplinaires de formation et de recherche et des logiques professionnelles optimisant les perspectives d’emploi des étudiants. Mais qu’en est-il dans la réalité ? Notre intention, dans cet article, est d’expliciter quelques formes d’élaboration de l’ethos professionnel à partir d’une analyse comparative entre deux cohortes d’étudiants, apprentis et stagiaires, de masters en management du sport.Professionalisation has been one of the main trends of proposed reforms in higher education over recent decades. It is part of a dual trend that combines subject-specific training and research approaches and professional approaches to optimise students’ employment prospects. But what is the reality? Our intention in this article is to clarify some ways in which professional ethos is created, drawing on a comparative analysis of two cohorts of students, apprentices and trainees on Masters in Sports Management courses

Currents and Superpotentials in classical gauge invariant theories I. Local results with applications to Perfect Fluids and General Relativity

E. Noether's general analysis of conservation laws has to be completed in a Lagrangian theory with local gauge invariance. Bulk charges are replaced by fluxes of superpotentials. Gauge invariant bulk charges may subsist when distinguished one-dimensional subgroups are present. As a first illustration we propose a new {\it Affine action} that reduces to General Relativity upon gauge fixing the dilatation (Weyl 1918 like) part of the connection and elimination of auxiliary fields. It allows a comparison of most gravity superpotentials and we discuss their selection by the choice of boundary conditions. A second and independent application is a geometrical reinterpretation of the convection of vorticity in barotropic nonviscous fluids. We identify the one-dimensional subgroups responsible for the bulk charges and thus propose an impulsive forcing for creating or destroying selectively helicity. This is an example of a new and general Forcing Rule.Comment: 64 pages, LaTeX. Version 2 has two more references and one misprint corrected. Accepted in Classical and Quantum Gravit

Editorial: Writing the field of equity

Description to be added.Cannot be left empt

Remote monitoring of patients with implantable cardioverter-defibrillators: Can results from large clinical trials be transposed to clinical practice?

SummaryBackgroundRemote monitoring (RM) is increasingly used to follow up patients with implantable cardioverter-defibrillators (ICDs). Randomized control trials provide evidence for the benefit of this intervention, but data for RM in daily clinical practice with multiple-brands and unselected patients is lacking.AimsTo assess the effect of RM on patient management and clinical outcome for recipients of ICDs in daily practice.MethodsWe reviewed ICD recipients followed up at our institution in 2009 with RM or with traditional hospital only (HO) follow-up. We looked at the effect of RM on the number of scheduled ambulatory follow-ups and urgent unscheduled consultations, the time between onset of asymptomatic events to clinical intervention and the clinical effectiveness of all consultations. We also evaluated the proportion of RM notifications representing clinically relevant situations.ResultsWe included 355 patients retrospectively (RM: n=144, HO: n=211, 76.9% male, 60.3±15.2years old, 50.1% with ICDs for primary prevention and mean left ventricular ejection fraction 35.5±14.5%). Average follow-up was 13.5months. The RM group required less scheduled ambulatory follow-up consultations (1.8 vs. 2.1/patient/year; P<0.0001) and a far lower median time between the onset of asymptomatic events and clinical intervention (7 vs. 76days; P=0.016). Of the 784 scheduled ambulatory follow-up consultations carried out, only 152 (19.4%) resulted in therapeutic intervention or ICD reprogramming. We also found that the vast majority of RM notifications (61.9%) were of no clinical relevance.ConclusionRM allows early management of asymptomatic events and a reduction in scheduled ambulatory follow-up consultations in daily clinical practice, without compromising safety, endorsing RM as the new standard of care for ICD recipients

Increased Expression of Cytotoxic T-Lymphocyte-Associated Protein 4 by T Cells, Induced by B7 in Sera, Reduces Adaptive Immunity in Patients With Acute Liver Failure.

BACKGROUND & AIMS: Patients with acute liver failure (ALF) have defects in innate immune responses to microbes (immune paresis) and are susceptible to sepsis. Cytotoxic T-lymphocyte-associated protein 4 (CTLA4), which interacts with the membrane receptor B7 (also called CD80 and CD86), is a negative regulator of T-cell activation. We collected T cells from patients with ALF and investigated whether inhibitory signals down-regulate adaptive immune responses in patients with ALF. METHODS: We collected peripheral blood mononuclear cells from patients with ALF and controls from September 2013 through September 2015 (45 patients with ALF, 20 patients with acute-on-chronic liver failure, 15 patients with cirrhosis with no evidence of acute decompensation, 20 patients with septic shock but no cirrhosis or liver disease, and 20 healthy individuals). Circulating CD4+ T cells were isolated and analyzed by flow cytometry. CD4+ T cells were incubated with antigen, or agonist to CD3 and dendritic cells, with or without antibody against CTLA4; T-cell proliferation and protein expression were quantified. We measured levels of soluble B7 molecules in supernatants of isolated primary hepatocytes, hepatic sinusoidal endothelial cells, and biliary epithelial cells from healthy or diseased liver tissues. We also measured levels of soluble B7 serum samples from patients and controls, and mice with acetaminophen-induced liver injury using enzyme-linked immunosorbent assays. RESULTS: Peripheral blood samples from patients with ALF had a higher proportion of CD4+ CTLA4+ T cells than controls; patients with infections had the highest proportions. CD4+ T cells from patients with ALF had a reduced proliferative response to antigen or CD3 stimulation compared to cells from controls; incubation of CD4+ T cells from patients with ALF with an antibody against CTLA4 increased their proliferative response to antigen and to CD3 stimulation, to the same levels as cells from controls. CD4+ T cells from controls up-regulated expression of CTLA4 after 24-48 hours culture with sera from patients with ALF; these sera were found to have increased concentrations of soluble B7 compared to sera from controls. Necrotic human primary hepatocytes exposed to acetaminophen, but not hepatic sinusoidal endothelial cells and biliary epithelial cells from patients with ALF, secreted high levels of soluble B7. Sera from mice with acetaminophen-induced liver injury contained high levels of soluble B7 compared to sera from mice without liver injury. Plasma exchange reduced circulating levels of soluble B7 in patients with ALF and expression of CTLA4 on T cells. CONCLUSIONS: Peripheral CD4+ T cells from patients with ALF have increased expression of CTLA4 compared to individuals without ALF; these cells have a reduced response to antigen and CD3 stimulation. We found sera of patients with ALF and from mice with liver injury to have high concentrations of soluble B7, which up-regulates CTLA4 expression by T cells and reduces their response to antigen. Plasma exchange reduces levels of B7 in sera from patients with ALF and might be used to restore antimicrobial responses to patients

Polar oceans and sea ice in a changing climate

Polar oceans and sea ice cover 15% of the Earth’s ocean surface, and the environment is changing rapidly at both poles. Improving knowledge on the interactions between the atmospheric and oceanic realms in the polar regions, a Surface Ocean–Lower Atmosphere Study (SOLAS) project key focus, is essential to understanding the Earth system in the context of climate change. However, our ability to monitor the pace and magnitude of changes in the polar regions and evaluate their impacts for the rest of the globe is limited by both remoteness and sea-ice coverage. Sea ice not only supports biological activity and mediates gas and aerosol exchange but can also hinder some in-situ and remote sensing observations. While satellite remote sensing provides the baseline climate record for sea-ice properties and extent, these techniques cannot provide key variables within and below sea ice. Recent robotics, modeling, and in-situ measurement advances have opened new possibilities for understanding the ocean–sea ice–atmosphere system, but critical knowledge gaps remain. Seasonal and long-term observations are clearly lacking across all variables and phases. Observational and modeling efforts across the sea-ice, ocean, and atmospheric domains must be better linked to achieve a system-level understanding of polar ocean and sea-ice environments. As polar oceans are warming and sea ice is becoming thinner and more ephemeral than before, dramatic changes over a suite of physicochemical and biogeochemical processes are expected, if not already underway.These changes in sea-ice and ocean conditions will affect atmospheric processes by modifying the production of aerosols, aerosol precursors, reactive halogens and oxidants, and the exchange of greenhouse gases. Quantifying which processes will be enhanced or reduced by climate change calls for tailored monitoring programs for high-latitude ocean environments. Open questions in this coupled system will be best resolved by leveraging ongoing international and multidisciplinary programs, such as efforts led by SOLAS, to link research across the ocean–sea ice–atmosphere interface

Leucine-Rich Glioma-Inactivated 1 Encephalitis: Broadening the Sphere

Background: Leucine-rich glioma-inactivated 1 (LGI1) encephalitis is a rare entity. Its typical features are seizures, faciobrachial dystonic seizures (FBDS), cognitive impairment, and personality changes. Case report: We report the case of a 66-year-old man with an unusual presentation, consisting of two types of FBDS, one starting in the foot and the other consisting of asynchronous myoclonic and dystonic jerks of the face triggered by noise and chin stimulation. The patient displayed no personality changes or cognitive impairment. Discussion: LGI1 encephalitis is a heterogeneous disease. Many different forms of FBDS may be observed, and these seizures can be the only symptom. This type of encephalitis should be suspected in presenting very frequent episodic events with dystonic features, regardless of the part of the body affected