DGM-FD: A Finite Difference Scheme Based on the Discontinuous Galerkin Method

Accurate and efficient numerical wave propagation is important in many areas of study such as computational aero-acoustics (CAA). While dissipation and dispersion errors influence the accuracy of a method, efficiency can be assessed by convergence rates and effective adaptability to different mesh structures. Finite difference and finite element methods are commonly used numerical schemes in CAA. Finite difference methods have the advantages of ease of use as well as high order convergence, but often require a uniform grid, and stable boundary closure can be non-trivial. Finite element methods adapt well to different mesh structures but can become difficult to implement as the order of approximation increases. In this research we formulate a numerical method that has high-order convergence, with strong accuracy for numerical wave numbers, and is adaptive to non-uniform grids. Such a method is developed based on the Discontinuous Galerkin Method (DGM) applied to the hyperbolic equation. Finite difference type schemes applicable to non-uniform grids are proposed. The schemes will be referred to as DGM-FD schemes. These schemes inherit, naturally, some features of the DGM, such as high-order approximations, applicability to non-uniform grids and super-accuracy for wave propagations. Two grid structures are studied. In the first structure, a regular, but non-uniform, finite difference type grid is assumed. In the second structure, some grid points are double-valued and the derivative scheme has a shortened stencil. Fourth-order upwind and third order central schemes are presented as examples of the first grid structure. Fifth-order upwind schemes are derived for the second structure. For non-linear equations, flux finite difference formula are given where no explicit upwind and downwind split of the flux is needed. This is in contrast to existing upwind finite difference schemes in the literature. Stability of the schemes with boundary closures and the super-accuracy for wave propagation problems are investigated and validated. The new schemes are demonstrated by numerical examples including the linearized acoustic waves, the solution of non-linear Burger\u27s equation and the flat-plate boundary layer problem

(VIDEO) Latino Immigration and Chronic Disease: A Critical Analysis of Socioeconomic and Psychological Mediators

A critical analysis of chronic disease among Latino immigrants demonstrates the interplay between the individual, socioeconomic, and pathophysiological mediators of disease. To identify the major factors involved, a conceptual framework was developed to explain the relationship between Latino immigration to the US and the manifestation of diabetes and cardiovascular disease. Mediating factors include: self-efficacy, stress, social support, access to healthcare, pathophysiological risk factors and the familial and cultural environment. As the Latino population is the fastest growing and largest minority group in America, increased support among the identified factors will target interventions with broad health and economic implications for the entire nation. Objective: Latinos are the largest minority group in the United States and are anticipated to represent 25% of the population by 2050. Latinos as a whole collectively experience a disproportionate burden of poverty and poor health outcomes, when compared to the rest of the national population. A heavy burden of disease among the largest minority group in America creates a compelling argument for resource application and investment to reduce the overall impending strain on an already strained healthcare system. The specific aim of the critical analysis was to development a conceptual framework clarifying the root causes and associated factors that contribute to Latino immigrant health. Creating a robust conceptual framework contributes to future academia and builds a base and springboard for future research. Doing so ultimately facilitates the development of program plans and grant proposals for future interested researchers and community clinics, as they develop calls for action and plan interventions and programs. By creating a comprehensive and thorough conceptual framework via critical analysis, the research contributes to the larger discussion of immigrant health. It strengthens and validates the argument that a further investment of resources, time and passion among researchers is needed to improve immigrant health outcomes. The overarching goal is for the critical analysis to be fundamentally useful for community clinics to develop public health programs, provide concrete evidence, and direct their efforts to improve Latino immigrant health. Methods: The main procedure for reviewing literature and conducting the critical analysis involves searching online journals. The primary research journals and search platforms used include: Google Scholar, PubMed, Medline, JSTOR, Scientific American, American Journal of Clinical Nutrition, SAGE Journals, Springer, NCBI and the Lancet. The literature review was conducted with strict research criteria. Criteria include publication data range, study design type, search terms, and inclusion and exclusion criteria. The inclusion and exclusion criteria comprise the most critical component of critical analysis. Having strict definitions of what articles can be included will facilitate data collection, analysis, and the final write up. Specific research criteria will guide the literature review and analysis. Research criteria concerns specifications for data range, study design, search terms, inclusion/exclusion criteria and databases used. Data Range Limitations: The data range was limited to publications from 1990-present, emphasizing publications from 2008 to the present. Older articles, prior to 2008, may be used to develop baseline data. Study Design Limitations: The study designs of analyzed research papers include: longitudinal case-control or cohort studies. The longitudinal observational studies can be used for socioeconomic, psychological, behavioral, biological and environmental factors. Participant samples must be: of Latino or Hispanic backgrounds, immigrants or first-generation families, and have chronic health conditions, such as Type II diabetes, obesity, cardiovascular disease. Search terms: diabetes, cardiovascular disease, hypertension, chronic disease, immigrant, Latino, hormonal imbalance, insulin, glucagon, inflammation, diabetic nephropathy/retinopathy, socioeconomic status, poverty, broken window syndrome, environment, stress, chronic stress, depression Studies eligible for inclusion had to meet the following selection criteria: - Exposure variable: social, economic, or behavioral experiences of Latino or Hispanic patients - Outcome variable: chronic disease - Designed as a longitudinal case-control or cohort study - Community or population based Selection of Literature The primary literature collection and review yielded 112 articles pertaining to the specific search criteria. After title and abstract review, 63 were selected for relevancy. Full text evaluation and data collection yielded 46 articles. 40 papers were finally selected, after excluding 6 for insufficient sample size, data, or being incomplete longitudinal studies. Results: Critical analysis of the selected literature gave evidence of an interconnected relationship among individual and socioeconomic factors and the pathophysiology of diabetes and CVD. INDIVIDUAL FACTORS - Race and Ethnicity: Race and ethnicity classification is a primary measure influencing a person’s world-view and interaction with society or health problems. Identifying as Latino affects the lived experience of disease and how Latinos in the US navigate chronic disease control, maintenance, and prevention. Understanding chronic disease among Latinos in the US poses significant challenges. - Acculturation and Self-Efficacy: Acculturation, or the process of social and psychological change from blending native and host cultures, has been used as a measurement of immigrant adaptation status Indicative of language and culture adoption, acculturation level is associated with depression, socioeconomic standing, education, social isolation and health care navigation. Less fluent linguistic capabilities may prevent opportunities for financial or socioeconomic advancement, by inhibiting successful negotiation of educational or job opportunities. Language barriers particularly impair immigrant advancement, promoting social isolation and preventing integration into the dominant host culture. Less acculturated immigrants face more barriers to health care, are less likely to have health insurance, and may not be educated about chronic disease risk factors compared to their more acculturated counterparts. - Personal Stressors: Immigrants experience a myriad of personal stressors from both the immigration process and cultural assimilation. The analysis of personal stress among US Latinos indicated a consistent association with increased chronic stress, CVD and major CVD risk factors, such as diabetes and smoking. Conclusion: The conceptual framework explains the relationship between Latino immigration to the US and the manifestation of diabetes and cardiovascular disease. By identifying the unique components that contribute to the lived disease experience of Latinos, public health interventions and community programs may target potential areas of the acculturation experience to improve immigrant health. If acculturation can be reframed as a more positive experience, with adoption of healthier activities, then minority and national health overall may improve

A phylogeny of Setaria (Poaceae, Panicoideae, Paniceae) and related genera based on the chloroplast gene ndhF

The genus Setaria is the largest genus in the so-called bristle clade, a monophyletic group of panicoid grasses distinguished by the presence of sterile branches, or bristles, in their inflorescences. The clade includes both foxtail millet and pearl millet, the latter an important cereal crop in dry parts of the world. Other members of the clade are weeds that are widespread agricultural pests. Previous molecular phylogenetic studies have suggested that Setaria might not be monophyletic but did not have a large enough sample of species to test this rigorously. In addition, taxonomic studies have suggested a close relationship between Setaria and Paspalidium, with some authors combining them into a single genus, but molecular studies included too few Paspalidium accessions for a meaningful conclusion. Accordingly, we have produced 77 new sequences of the chloroplast gene ndhF for 52 species not in previous analyses. These were added to available sequences for 35 species in 10 genera of the bristle clade and four outgroup taxa. We find that Setaria species fall into several moderately to strongly supported clades that correlate with geography but not with the existing subgeneric classification. Relationships among these clades and among other genera within the bristle clade are unclear. Constraint experiments using the approximately unbiased test reject the monophyly of Pennisetum, Setaria, and Setaria plus Paspalidium, as well as several other groupings, although the test may be overly sensitive and prone to Type I error. The more conservative Shimodaira-Hasegawa test fails to reject monophyly of any of the tested clades.Fil: Kellogg, Elizabeth Anne. University of Missouri; Estados UnidosFil: Aliscioni, Sandra Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Cátedra de Botánica Agrícola; ArgentinaFil: Morrone, Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Pensiero, Jose Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Zuloaga, Fernando Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentin

Le pouvoir de la grâce : le projet politique d'Hernando de Salazar, confesseur du comte-duc d'Olivares

International audienceProponemos un estudio del proyecto político que jesuita Fernando de Salazar, confesor del conde duque de Olivares, somete al valido de Felipe IV en 1625, buscando dar cuenta de su ambición reformadora sin que sea necesario enmarcarlo en el paradigma clásico del Estado moderno. El manuscrito estudiado, una síntesis de los proyectos que se discuten en aquel entonces en el entorno de Olivares, promueve un reforzamiento del carácter gracioso de la gracia real - mediatizada por el valido- dinamizando a la vez la negociación con los representantes autorizados de los distintos cuerpos del reino. Salazar comparte las críticas al uso del sistema polisinodial y pretende confiar el gobierno de la monarquía a juntas controladas por fieles del valido, capaces de poner en obra la reforma. En el nuevo paisaje institucional que diseña Salazar, el confesor del valido, así como el del rey, no tiene espacio asignado. Para nosotros, lejos de reducir el poder del confesor del valido aquí, Salazar se niega a imponerle límitesNous proposons une étude du projet politique soumis au comte-duc d'Olivares par son confesseur, le jésuite Hernando de Salazar, en 1625, qui donne la mesure de sa portée réformatrice sans pour autant le rattacher au paradigme classique de l'Etat moderne. Le manuscrit étudié, qui fait la synthèse des projets alors agités dans l'entourage d'Olivares, promeut un renforcement caractère gracieux de la grâce royale - médiatisée par le favori du roi - tout en relançant la négociation avec les représentants autorisés des différents corps du royaume. Salazar partage les critiques du système polysynodal et prétend confier le gouvernement à des juntes contrôlées par des fidèles du favori, susceptibles de mettre en œuvre cette réforme. Dans le nouveau paysage institutionnel qu'il dessine, le confesseur du favori, tout comme celui du roi, n'ont pas de place assignée. A notre sens, loin d'amoindrir ici le pouvoir du confesseur du favori, Salazar se refuse à lui imposer des limites

Investigation of precipitated calcium carbonate as a processing aid and impact modifier in poly(vinyl chloride)

The effect of ultra-fine precipitated calcium carbonate (PCC), with a primary particle size of 50 nm, on the fusion behavior and mechanical properties of Ca/Zn stabilized poly(vinyl chloride) PVC has been investigated. The optimum concentration of PCC was determined and, in addition, experimental design was used to examine possible synergies between PCC and two important additives in an unplasticized PVC (PVC-U) formulation: namely, the processing aid and impact modifier. Dry blends were extruded and tested by differential scanning calorimetry, tensile testing, and Charpy impact testing. The results confirm that ultrafine PCC can give rise to large improvements in single notch impact strengths. Control values of 8 kJ/m were increased to 79 kJ/m through the addition of ultra-fine PCC. There was also found to be a significant increase in fusion levels but no effect on the tensile strength of the samples. It is concluded that PCC behaves as both a processing aid and impact modifier in PVC-U formulations, and the reasons for this are discussed

The diversity of population responses to environmental change

The current extinction and climate change crises pressure us to predict population dynamics with ever‐greater accuracy. Although predictions rest on the well‐advanced theory of age‐structured populations, two key issues remain poorly explored. Specifically, how the age‐dependency in demographic rates and the year‐to‐year interactions between survival and fecundity affect stochastic population growth rates. We use inference, simulations and mathematical derivations to explore how environmental perturbations determine population growth rates for populations with different age‐specific demographic rates and when ages are reduced to stages. We find that stage‐ vs. age‐based models can produce markedly divergent stochastic population growth rates. The differences are most pronounced when there are survival‐fecundity‐trade‐offs, which reduce the variance in the population growth rate. Finally, the expected value and variance of the stochastic growth rates of populations with different age‐specific demographic rates can diverge to the extent that, while some populations may thrive, others will inevitably go extinct

The effect of precipitated calcium carbonate on the mechanical properties of poly(vinyl chloride)

This study examines the effect of various grades of precipitated and ground calcium carbonate on the tensile strength and Charpy impact energy of extruded PVC profile. The results confirm that ultra-fine precipitated calcium carbonate (pcc) can give rise to large improvements in single notch impact strengths. Control values of 9 kJm-2 were increased to 79 kJm-2 through the addition of ultra-fine pcc. The results have been interpreted in terms of the particle size, shape and coating of the calcium carbonate grades and the effect on the gelation characteristics of the PVC formulations

Importance of the Inverted Control in Measuring Holistic Face Processing with the Composite Effect and Part-Whole Effect

Holistic coding for faces is shown in several illusions that demonstrate integration of the percept across the entire face. The illusions occur upright but, crucially, not inverted. Converting the illusions into experimental tasks that measure their strength - and thus index degree of holistic coding - is often considered straightforward yet in fact relies on a hidden assumption, namely that there is no contribution to the experimental measure from secondary cognitive factors. For the composite effect, a relevant secondary factor is size of the "spotlight" of visuospatial attention. The composite task assumes this spotlight can be easily restricted to the target half (e.g., top-half) of the compound face stimulus. Yet, if this assumption were not true then a large spotlight, in the absence of holistic perception, could produce a false composite effect, present even for inverted faces and contributing partially to the score for upright faces. We review evidence that various factors can influence spotlight size: race/culture (Asians often prefer a more global distribution of attention than Caucasians); sex (females can be more global); appearance of the join or gap between face halves; and location of the eyes, which typically attract attention. Results from five experiments then show inverted faces can sometimes produce large false composite effects, and imply that whether this happens or not depends on complex interactions between causal factors. We also report, for both identity and expression, that only top-half face targets (containing eyes) produce valid composite measures. A sixth experiment demonstrates an example of a false inverted part-whole effect, where encoding-specificity is the secondary cognitive factor. We conclude the inverted face control should be tested in all composite and part-whole studies, and an effect for upright faces should be interpreted as a pure measure of holistic processing only when the experimental design produces no effect inverted.Australian Research Council DP0984558 to Elinor McKone; Australian Research Council Centre of Excellence in Cognition and its Disorders (project number CE110001021); Kate Crookes salary supported by Hong Kong Research Grants Council grant (HKU744911) to William Hayward

A risk management system for sustainable fleet replacement.

This article analyzes the fleet management problem faced by a firm when deciding which vehicles to add to its fleet. Such a decision depends not only on the expected mileage and tasks to be assigned to the vehicle but also on the evolution of fuel and CO2 emission prices and on fuel efficiency. This article contributes to the literature on fleet replacement and sustainable operations by proposing a general decision support system for the fleet replacement problem using stochastic programming and conditional value at risk (CVaR) to account for uncertainty in the decision process. The article analyzes how the CVaR associated with different types of vehicle is affected by the parameters in the model by reporting on the results of a real-world case study