Regularity of the optimal sets for some spectral functionals

In this paper we study the regularity of the optimal sets for the shape optimization problem min{λ1(Ω)+⋯+λk(Ω) : Ω⊂Rd open, |Ω|=1}, where λ1(·) , … , λk(·) denote the eigenvalues of the Dirichlet Laplacian and | · | the d-dimensional Lebesgue measure. We prove that the topological boundary of a minimizer Ωk∗ is composed of a relatively open regular part which is locally a graph of a C∞ function and a closed singular part, which is empty if d< d∗, contains at most a finite number of isolated points if d= d∗ and has Hausdorff dimension smaller than (d- d∗) if d> d∗, where the natural number d∗∈ [ 5 , 7 ] is the smallest dimension at which minimizing one-phase free boundaries admit singularities. To achieve our goal, as an auxiliary result, we shall extend for the first time the known regularity theory for the one-phase free boundary problem to the vector-valued case

On the bend number of circular-arc graphs as edge intersection graphs of paths on a grid

Golumbic, Lipshteyn and Stern \cite{Golumbic-epg} proved that every graph can be represented as the edge intersection graph of paths on a grid (EPG graph), i.e., one can associate with each vertex of the graph a nontrivial path on a rectangular grid such that two vertices are adjacent if and only if the corresponding paths share at least one edge of the grid. For a nonnegative integer $k$, $B_k$-EPG graphs are defined as EPG graphs admitting a model in which each path has at most $k$ bends. Circular-arc graphs are intersection graphs of open arcs of a circle. It is easy to see that every circular-arc graph is a $B_4$-EPG graph, by embedding the circle into a rectangle of the grid. In this paper, we prove that every circular-arc graph is $B_3$-EPG, and that there exist circular-arc graphs which are not $B_2$-EPG. If we restrict ourselves to rectangular representations (i.e., the union of the paths used in the model is contained in a rectangle of the grid), we obtain EPR (edge intersection of path in a rectangle) representations. We may define $B_k$-EPR graphs, $k\geq 0$, the same way as $B_k$-EPG graphs. Circular-arc graphs are clearly $B_4$-EPR graphs and we will show that there exist circular-arc graphs that are not $B_3$-EPR graphs. We also show that normal circular-arc graphs are $B_2$-EPR graphs and that there exist normal circular-arc graphs that are not $B_1$-EPR graphs. Finally, we characterize $B_1$-EPR graphs by a family of minimal forbidden induced subgraphs, and show that they form a subclass of normal Helly circular-arc graphs

Perturbations of the optical properties of mineral dust particles by mixing with black carbon: A numerical simulation study

Field observations show that individual aerosol particles are a complex mixture of a wide variety of species, reflecting different sources and physico-chemical transformations. The impacts of individual aerosol morphology and mixing characteristics on the Earth system are not yet fully understood. Here we present a sensitivity study on climate-relevant aerosols optical properties to various approximations. Based on aerosol samples collected in various geographical locations, we have observationally constrained size, morphology and mixing, and accordingly simulated, using the discrete dipole approximation model (DDSCAT), optical properties of three aerosols types: (1) bare black carbon (BC) aggregates, (2) bare mineral dust, and (3) an internal mixture of a BC aggregate laying on top of a mineral dust particle, also referred to as polluted dust. DDSCAT predicts optical properties and their spectral dependence consistently with observations for all the studied cases. Predicted values of mass absorption, scattering and extinction coefficients (MAC, MSC, MEC) for bare BC show a weak dependence on the BC aggregate size, while the asymmetry parameter (g) shows the opposite behavior. The simulated optical properties of bare mineral dust present a large variability depending on the modeled dust shape, confirming the limited range of applicability of spheroids over different types and size of mineral dust aerosols, in agreement with previous modeling studies. The polluted dust cases show a strong decrease in MAC values with the increase in dust particle size (for the same BC size) and an increase of the single scattering albedo (SSA). Furthermore, particles with a radius between 180 and 300 nm are characterized by a decrease in SSA values compared to bare dust, in agreement with field observations. This paper demonstrates that observationally constrained DDSCAT simulations allow one to better understand the variability of the measured aerosol optical properties in ambient air and to define benchmark biases due to different approximations in aerosol parametrization

Esposas de jogadores patológicos: traços de personalidade, sintomas depressivos e ajustamento social

Objective: Wives of pathological gamblers tend to endure long marriages despite financial and emotional burden. Difficulties in social adjustment, personality psychopathology, and comorbidity with psychiatric disorders are pointed as reasons for remaining on such overwhelming relationships. The goal was to examine the social adjustment, personality and negative emotionality of wives of pathological gamblers. Method: The sample consisted of 25 wives of pathological gamblers, mean age 40.6, SD = 9.1 from a Gambling Outpatient Unit and at GAM-ANON, and 25 wives of non-gamblers, mean age 40.8, SD = 9.1, who answered advertisements placed at the Universidade de São Paulo hospital and medical school complex. They were selected in order to approximately match demographic characteristics of the wives of pathological gamblers. Subjects were assessed by the Social Adjustment Scale, Temperament and Character Inventory, Beck Depression Inventory and State-Trait Anxiety Inventory. Results: Three variables remained in the final Multiple Logistic Regression model, wives of pathological gamblers presented greater dissatisfaction with their marital bond, and higher scores on Reward Dependence and Persistence temperament factors. Both, Wives of pathological gamblers and wives of non-gamblers presented well-structured character factors excluding personality disorders. Conclusion: This personality profile may explain wives of pathological gamblers emotional resilience and their marriage longevity. Co-dependence and other labels previously used to describe them may work as a double edged sword, legitimating wives of pathological gamblers problems, while stigmatizing them as inapt and needy.Objetivo: Esposas de jogadores patológicos tendem a permanecer casadas por muitos anos, apesar das dificuldades financeiras e emocionais. Dificuldades de ajustamento social, transtornos de personalidade, e comorbidades com transtornos psiquiátricos são apontados como razões para permanecerem nesses relacionamentos tão opressivos. O objetivo foi examinar o ajustamento social, a personalidade e as emoções negativas das esposas de jogadores patológicos. Método: A amostra foi constituída por 25 esposas de jogadores patológicos, média de idade 40,6 anos (DP = 9,1), do Ambulatório de Jogadores Patológicos e do Jog-Anon, e 25 esposas de não jogadores, média de idade 40,8 anos (DP = 9,1), que responderam a anúncios colocados no complexo do hospital da faculdade de medicina da Universidade de São Paulo. Foram selecionadas aquelas que apresentavam características demográficas próximas às das esposas de jogadores patológicos. Os sujeitos foram avaliados por meio da Escala de Ajustamento Social, do Inventário de Temperamento e Caráter, do Inventário de Depressão de Beck, e do Inventário de Ansiedade Traço-Estado. Resultados: Três variáveis permaneceram no modelo final da Análise de Regressão Logística Múltipla. Esposas de jogadores patológicos apresentaram maior insatisfação no relacionamento marital e escores mais altos nos fatores de temperamento Dependência de Gratificação e Persistência. Ambas, as esposas de jogadores patológicos e de não jogadores apresentaram fatores de caráter bem estruturados, excluindo transtornos de personalidade. Conclusão: Este perfil de personalidade pode explicar a resiliência emocional das esposas de jogadores patológicos e a longa duração de seus casamentos. Codependência e outros rótulos utilizados anteriormente para descrevê-las podem, de um lado, legitimar seus problemas e, de outro, estigmatizá-las como inaptas e carentes

Molecular and physical characteristics of aerosol at a remote free troposphere site: implications for atmospheric aging

Aerosol properties are transformed by atmospheric processes during long-range transport and play a key role in the Earth's radiative balance. To understand the molecular and physical characteristics of free tropospheric aerosol, we studied samples collected at the Pico Mountain Observatory in the North Atlantic. The observatory is located in the marine free troposphere at 2225&thinsp;m above sea level, on Pico Island in the Azores archipelago. The site is ideal for the study of long-range-transported free tropospheric aerosol with minimal local influence. Three aerosol samples with elevated organic carbon concentrations were selected for detailed analysis. FLEXPART retroplumes indicated that two of the samples were influenced by North American wildfire emissions transported in the free troposphere and one by North American outflow mainly transported within the marine boundary layer. Ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry was used to determine the detailed molecular composition of the samples. Thousands of molecular formulas were assigned to each of the individual samples. On average  ∼ 60&thinsp;% of the molecular formulas contained only carbon, hydrogen, and oxygen atoms (CHO),  ∼ 30&thinsp;% contained nitrogen (CHNO), and  ∼ 10&thinsp;% contained sulfur (CHOS). The molecular formula compositions of the two wildfire-influenced aerosol samples transported mainly in the free troposphere had relatively low average O∕C ratios (0.48±0.13 and 0.45±0.11) despite the 7–10 days of transport time according to FLEXPART. In contrast, the molecular composition of the North American outflow transported mainly in the boundary layer had a higher average O∕C ratio (0.57±0.17) with 3 days of transport time. To better understand the difference between free tropospheric transport and boundary layer transport, the meteorological conditions along the FLEXPART simulated transport pathways were extracted from the Global Forecast System analysis for the model grids. We used the extracted meteorological conditions and the observed molecular chemistry to predict the relative-humidity-dependent glass transition temperatures (Tg) of the aerosol components. Comparisons of the Tg to the ambient temperature indicated that a majority of the organic aerosol components transported in the free troposphere were more viscous and therefore less susceptible to oxidation than the organic aerosol components transported in the boundary layer. Although the number of observations is limited, the results suggest that biomass burning organic aerosol injected into the free troposphere is more persistent than organic aerosol in the boundary layer having broader implications for aerosol aging.</p

Measurements of ice nucleation by mineral dusts in the contact mode

Formation of ice in Earth\u27s atmosphere at temperatures above approximately −20 °C is one of the outstanding problems in cloud physics. Contact nucleation has been suggested as a possible mechanism for freezing at relatively high temperatures; some laboratory experiments have shown contact freezing activity at temperatures as high as −4 °C. We have investigated Arizona Test Dust and kaolinite as contact nuclei as a function of size and temperature and find that the fraction of submicron particles that are active as contact ice nuclei is less than 10−3 for −18 °C and greater. We also find that the different dusts are quite distinct in their effectiveness as contact nuclei; Arizona Test Dust catalyzed freezing in the contact mode at all mobility diameters we tested at −18 °C whereas kaolinite triggered freezing only for mobility diameters of 1000 and 500 nm at that temperature

Ice cloud formation potential by free tropospheric particles from long-range transport over the Northern Atlantic Ocean

Long-range transported free tropospheric particles can play a significant role on heterogeneous ice nucleation. Using optical and electron microscopy we examine the physicochemical characteristics of ice nucleating particles (INPs). Particles were collected on substrates from the free troposphere at the remote Pico Mountain Observatory in the Azores Islands, after long-range transport and aging over the Atlantic Ocean. We investigate four specific events to study the ice formation potential by the collected particles with different ages and transport patterns. We use single-particle analysis, as well as bulk analysis to characterize particle populations. Both analyses show substantial differences in particle composition between samples from the four events; in addition, single-particle microscopy analysis indicates that most particles are coated by organic material. The identified INPs contained mixtures of dust, aged sea salt and soot, and organic material acquired either at the source or during transport. The temperature and relative humidity (RH) at which ice formed, varied only by 5% between samples, despite differences in particle composition, sources, and transport patterns. We hypothesize that this small variation in the onset RH may be due to the coating material on the particles. This study underscores and motivates the need to further investigate how long-range transported and atmospherically aged free tropospheric particles impact ice cloud formatio

Robot-mediated therapy for paretic upper limb of chronic patients following neurological injury

Objective: To evaluate the effectiveness of robot-mediated therapy targeted at the motor recovery of the upper limb in chronic patients following neurological injury

The Digital Image Correlation technique applied to the deformation behavior of welded sheet joints

The existence of a welded zone generally influences the local strain and stress distribution especially in case of welding defects. A method able to measure the local deformability can hence give many important information about the real stress and strain fields useful to improve the welded structure design. In this experimental work, some new generation automotive steels have been considered, because of the well known welding problems due to their unstable microstructural condition. Such materials, known as Q&P steels and available only as thin sheets, require a suitable quenching process able to give high mechanical resistance and satisfying deformability. Some sheet samples were welded by electron beam technique, because it is able to reduce the width of the heat affected zone where the main microstructural changes are concentrated. From such samples, tensile specimens were machined. During the tensile tests, the deformations were measured both by a traditional extensometer and by a 3D Digital Image Correlation (3D DIC) technique. A preliminary investigation of the melted and the heat affected zones resulted in small dimensions (about 10 mm) and hence the measuring setup has been optimized in order maximize the achievable measuring resolution minimizing the resulting uncertainty. This result can be achieved by a pattern generated by a suitable software and by an accurate preparation of the surface where the pattern will be deposited on

Barriers and facilitators to the implementation of nurse’s role in primary care settings: an integrative review

Background: The rapid evolution of the epidemiological picture and the recent SARS-COV-2 pandemic has expressed the vulnerabilities of health systems and focuses attention on the population’s needs. The nurse’s figure in the care teams is universally identified; however, the implementation of the role within some care settings turns out to be complex and challenging. This integrative review aims to identify the barriers and facilitators in implementing the role of the nurse in primary care settings. Methods: An integrative review was conducted on the Medline and Cinahl databases until 9 June 2020. Qualitative, quantitative, and Mixed-method research studies were selected to identify studies related to the barriers and facilitators of the nurse’s role in nursing facilities’ primary care. For the extraction of the results, the Consolidating Framework for Research Implementation (CFIR) was used to identify the factors that influence implementation in health care. Results: Following the duplicates’ removal, the search identified 18,257 articles, of which 56 were relevant to the inclusion criteria; therefore, they were included in the summary. The selected studies were conducted in thirteen countries, most from Oceania, Europe, North America, Latin America, and the Caribbean. The barriers reported most frequently concern the nursing profession’s regulatory and regulatory aspects within the contexts of care, cultural and organizational aspects, training, and the transfer of specific skills, which were previously designated to doctors. The facilitators are mainly linked to the nurse’s adaptability to the various contexts of care, recognizing the patient’s role, and the desire to develop multidisciplinary and effective working groups to respond to the health needs of the population in primary care contexts. Conclusion: This review highlighted the main barriers and facilitators in implementing the nurse’s role in primary care settings. These results offer useful elements for stakeholders to identify effective strategies in preparing programs and activities for implementing the nurse’s role, acting on the elements identified as barriers and favouring the aspects that emerge as facilitators