Elasticity of Substitution in the U.S. Market with Endogenous Transport Costs: a Sectoral Approach.

En este artículo se presentan estimaciones de la elasticidad de sustitución de bienes importados al mercado de los EEUU en el periodo 1990 - 2003, siguiendo a Anderson y Wincoop (2004). Estas estimaciones aprovechan la disponibilidad de la información sobre costos de transporte de bienes publicada por la Oficina del Censo de los Estados Unidos, desagregándola a seis digitos. Se obtienen dos estimaciones diferentes de la elasticidad de sustitución: una a nivel agregado promedio y otra a nivel sectorial. Como puede esperarse, las estimaciones que tienen en cuenta la endogeneidad de los costos de transporte son estadisticamente diferentes en un punto porcentual a los resultados obtenidos cuando no se contempla la estructura de los costos de transporte. Esta diferencia es incluso superior cuando comparamos los resultados obtenidos utilizando la clasificacion sectorial a nivel de dos digitos de la clasificacion ISIC revisión 2.

Proteomic profiling of neuromas reveals alterations in protein composition and local protein synthesis in hyper-excitable nerves

Neuropathic pain may arise following peripheral nerve injury though the molecular mechanisms associated with this are unclear. We used proteomic profiling to examine changes in protein expression associated with the formation of hyper-excitable neuromas derived from rodent saphenous nerves. A two-dimensional difference gel electrophoresis ( 2D-DIGE) profiling strategy was employed to examine protein expression changes between developing neuromas and normal nerves in whole tissue lysates. We found around 200 proteins which displayed a > 1.75-fold change in expression between neuroma and normal nerve and identified 55 of these proteins using mass spectrometry. We also used immunoblotting to examine the expression of low-abundance ion channels Nav1.3, Nav1.8 and calcium channel alpha 2 delta-1 subunit in this model, since they have previously been implicated in neuronal hyperexcitability associated with neuropathic pain. Finally, S(35)methionine in vitro labelling of neuroma and control samples was used to demonstrate local protein synthesis of neuron-specific genes. A number of cytoskeletal proteins, enzymes and proteins associated with oxidative stress were up-regulated in neuromas, whilst overall levels of voltage-gated ion channel proteins were unaffected. We conclude that altered mRNA levels reported in the somata of damaged DRG neurons do not necessarily reflect levels of altered proteins in hyper-excitable damaged nerve endings. An altered repertoire of protein expression, local protein synthesis and topological re-arrangements of ion channels may all play important roles in neuroma hyper-excitability.

Talent in autism: hyper-systemising, hyper-attention to detail and sensory hypersensitivity

We argue that hyper-systemizing predisposes individuals to show talent, and review evidence that hyper-systemizing is part of the cognitive style of people with autism spectrum conditions (ASC). We then clarify the hyper-systemizing theory, contrasting it to the weak central coherence (WCC) and executive dysfunction (ED) theories. The ED theory has difficulty explaining the existence of talent in ASC. While both hyper-systemizing and WCC theories postulate excellent attention to detail, by itself excellent attention to detail will not produce talent. By contrast, the hyper-systemizing theory argues that the excellent attention to detail is directed towards detecting 'if p, then q' rules (or [input-operation-output] reasoning). Such law-based pattern recognition systems can produce talent in systemizable domains. Finally, we argue that the excellent attention to detail in ASC is itself a consequence of sensory hypersensitivity. We review an experiment from our laboratory demonstrating sensory hypersensitivity detection thresholds in vision. We conclude that the origins of the association between autism and talent begin at the sensory level, include excellent attention to detail and end with hyper-systemizing.

The elasticity of demand is about occupancy, not prices: building European demand curves based on occupancy elasticity

The peak congestion of the European grid may create significant impacts on system costs because of the need for higher marginal cost generation, higher cost system balancing and increasing grid reinforcement investment. The use of time of use rates, incentives, real time pricing and other programmes, usually defined as Demand Side Management (DSM), could bring about significant reductions in prices, limit carbon emissions from dirty power plants, and improve the integration of renewable sources of energy. Unlike previous studies on elasticity of residential electricity demand under flat tariffs, the aim of this study is not to investigate the known relatively inelastic relationship between demand and prices. Rather, the aim is to assess how occupancy levels vary in different European countries. This reflects the reality of demand loads, which are predominantly determined by the timing of human activities (e.g. travelling to work, taking children to school) rather than prices. To this end, two types of occupancy elasticity are estimated: baseline occupancy elasticity and peak occupancy elasticity. These represent the intrinsic elasticity associated with human activities of single residential end-users in 15 European countries. This study makes use of occupancy time-series data from the Harmonised European Time Use Survey database to build European occupancy curves; identify peak occupancy periods; draw time use demand curves for video and TV watching activity; and estimate national occupancy elasticity levels of single-occupant households. Findings on occupancy elasticities provide an indication of possible DSM strategies based on occupancy levels and not prices.

Hyper-parallel tempering Monte Carlo simulations of Ar adsorption in new models of microporous non-graphitizing activated carbon: effect of microporosity

The adsorption of gases on microporous carbons is still poorly understood, partly because the structure of these carbons is not well known. Here, a model of microporous carbons based on fullerene- like fragments is used as the basis for a theoretical study of Ar adsorption on carbon. First, a simulation box was constructed, containing a plausible arrangement of carbon fragments. Next, using a new Monte Carlo simulation algorithm, two types of carbon fragments were gradually placed into the initial structure to increase its microporosity. Thirty six different microporous carbon structures were generated in this way. Using the method proposed recently by Bhattacharya and Gubbins ( BG), the micropore size distributions of the obtained carbon models and the average micropore diameters were calculated. For ten chosen structures, Ar adsorption isotherms ( 87 K) were simulated via the hyper- parallel tempering Monte Carlo simulation method. The isotherms obtained in this way were described by widely applied methods of microporous carbon characterisation, i. e. Nguyen and Do, Horvath - Kawazoe, high- resolution alpha(a)s plots, adsorption potential distributions and the Dubinin - Astakhov ( DA) equation. From simulated isotherms described by the DA equation, the average micropore diameters were calculated using empirical relationships proposed by different authors and they were compared with those from the BG method.

Plane wave approximation in linear elasticity

We consider the approximation of solutions of the time-harmonic linear elastic wave equation by linear combinations of plane waves. We prove algebraic orders of convergence both with respect to the dimension of the approximating space and to the diameter of the domain. The error is measured in Sobolev norms and the constants in the estimates explicitly depend on the problem wavenumber. The obtained estimates can be used in the h- and p-convergence analysis of wave-based finite element schemes.

Food restriction reverses the hyper-muscular phenotype and force generation capacity deficit of the myostatin null mouse

Food restriction has a great impact on skeletal muscle mass by inducing muscle protein breakdown to provide substrates for energy production through gluconeogenesis. Genetic models of hyper-muscularity interfere with the normal balance between protein synthesis and breakdown which eventually results in extreme muscle growth. Mutations or deletions in the myostatin gene result in extreme muscle mass. Here we evaluated the impact of food restriction for a period of 5 weeks on skeletal muscle size (i.e., fibre cross-sectional area), fibre type composition and contractile properties (i.e., tetanic and specific force) in myostatin null mice. We found that this hyper-muscular model was more susceptible to catabolic processes than wild type mice. The mechanism of skeletal muscle mass loss was examined and our data shows that the myostatin null mice placed on a low calorie diet maintained the activity of molecules involved in protein synthesis and did not up-regulate the expression of genes pivotal in ubiquitin-mediated protein degradation. However, we did find an increase in the expression of genes associated with autophagy. Surprisingly, the reduction on muscle size was followed by improved tetanic and specific force in the null mice compared to wild type mice. These data provide evidence that food restriction may revert the hyper-muscular phenotype of the myostatin null mouse restoring muscle function.

Collabowrighting the hyper(play)text: a postdramatic digital poetics

The aim of this research is to exhibit how literary playtexts can evoke multisensory trends prevalent in 21st century theatre. In order to do so, it explores a range of practical forms and theoretical contexts for creating participatory, site-specific and immersive theatre. With reference to literary theory, specifically to semiotics, reader-response theory, postmodernism and deconstruction, it attempts to revise dramatic theory established by Aristotle’s Poetics. Considering Gertrude Stein’s essay, Plays (1935), and relevant trends in theatre and performance, shaped by space, technology and the everchanging role of the audience member, a postdramatic poetics emerges from which to analyze the plays of Mac Wellman and Suzan-Lori Parks. Distinguishing the two textual lives of a play as the performance playtext and the literary playtext, it examines the conventions of the printed literary playtext, with reference to models of practice that radicalize the play form, including works by Mabou Mines, The Living Theatre and Fiona Templeton. The arguments of this practice-led Ph.D. developed out of direct engagement with the practice project, which explores the multisensory potential of written language when combined with hypermedia. The written thesis traces the development process of a new play, Rumi High, which is presented digitally as a ‘hyper(play)text,’ accessible through the Internet at www.RumiHigh.org. Here, ‘playwrighting’ practice is expanded spatially, collaboratively and textually. Plays are built, designed and crafted with many layers of meaning that explore both linguistic and graphic modes of poetic expression. The hyper(play)text of Rumi High establishes playwrighting practice as curatorial, where performance and literary playtexts are in a reciprocal relationship. This thesis argues that digital writing and reading spaces enable new approaches to expressing the many languages of performance, while expanding the collaborative network that produces the work. It questions how participatory forms of immersive and site-specific theatre can be presented as interactive literary playtexts, which enable the reader to have a multisensory experience. Through a reflection on process and an evaluation of the practice project, this thesis problematizes notions of authorship and text.

The impact of maternal cortisol concentrations on child arterial elasticity

Epidemiological studies suggest that glucocorticoid excess in the fetus may contribute to the pathophysiology of cardiovascular diseases in adulthood. However, the impact of maternal glucocorticoid on the cardiovascular system of the offspring has not been much explored in studies involving humans, especially in childhood. The objective of this study was to assess the influence of maternal cortisol concentrations on child arterial elasticity. One hundred and thirty pregnant women followed from 1997 to 2000, and respective children 5-7 years of age followed from 2004 to 2006 were included in the study. Maternal cortisol was determined in saliva by an enzyme immunoassay utilizing the mean concentration of nine samples of saliva. Arterial elasticity was assessed by the large artery elasticity index (LAEI; the capacitive elasticity of large arteries) by recording radial artery pulse wave, utilizing the equipment HDI/PulseWave CR-2000 Cardiovascular Profiling System (R). The nutritional status of the children was determined by the body mass index (BMI). Insulin concentration was assessed by chemiluminescence, and insulin resistance by the homeostasis model assessment. Blood glucose, total cholesterol and fractions (LDL-c and HDL-c) and triglyceride concentrations were determined by automated enzymatic methods. The association between maternal cortisol and child arterial elasticity was assessed by multivariate linear regression analysis. There was a statistically significant association between maternal cortisol and LAEI (P=0.02), controlling for birth weight, age, BMI and HDL-c of the children. This study suggests that exposure to higher glucocorticoid concentrations in the prenatal period is associated to lower arterial elasticity in childhood, an earlier cardiovascular risk marker.

Analysis of a hyper-diverse seed dispersal network: modularity and underlying mechanisms

Mutualistic interactions involving pollination and ant-plant mutualistic networks typically feature tightly linked species grouped in modules. However, such modularity is infrequent in seed dispersal networks, presumably because research on those networks predominantly includes a single taxonomic animal group (e.g. birds). Herein, for the first time, we examine the pattern of interaction in a network that includes multiple taxonomic groups of seed dispersers, and the mechanisms underlying modularity. We found that the network was nested and modular, with five distinguishable modules. Our examination of the mechanisms underlying such modularity showed that plant and animal trait values were associated with specific modules but phylogenetic effect was limited. Thus, the pattern of interaction in this network is only partially explained by shared evolutionary history. We conclude that the observed modularity emerged by a combination of phylogenetic history and trait convergence of phylogenetically unrelated species, shaped by interactions with particular types of dispersal agents.

A discontinuous-Galerkin-based immersed boundary method with non-homogeneous boundary conditions and its application to elasticity

We propose a discontinuous-Galerkin-based immersed boundary method for elasticity problems. The resulting numerical scheme does not require boundary fitting meshes and avoids boundary locking by switching the elements intersected by the boundary to a discontinuous Galerkin approximation. Special emphasis is placed on the construction of a method that retains an optimal convergence rate in the presence of non-homogeneous essential and natural boundary conditions. The role of each one of the approximations introduced is illustrated by analyzing an analog problem in one spatial dimension. Finally, extensive two- and three-dimensional numerical experiments on linear and nonlinear elasticity problems verify that the proposed method leads to optimal convergence rates under combinations of essential and natural boundary conditions. (C) 2009 Elsevier B.V. All rights reserved.

Price elasticity of demand for cigarettes : The Case of Sweden

Due to health problems and the negative externalities associated with cigarette consumption, many governments try to discourage cigarette consumption by increasing its price through taxation. However, cigarette, like the other addictive goods, is viewed as that it is not sensitive to demand rules and the market forces. This study analyses the effect of price increase on cigarette consumption. We used Swedish time series data from 1970 to 2010. Our results reveal that though cigarette is addictive substance its demand is sensitive to changes in the price. Estimates from this study indicate short-run price-elasticity of -0.29 and the long run price elasticity of -0.47.

Hyper-Automaton: avaliação interativa de alunos em cursos na WEB baseado em autômatos finitos

O objetivo desta dissertação é a elaboração de uma técnica da aplicação do formalismo de Autômatos Finitos com Saída (Máquina de Mealy e Máquina de Moore) como um modelo estrutural para a organização de hiperdocumentos instrucionais, em destacar especial, Avaliação e Exercício. Esse objetivo é motivado pela organização e agilização do processo de avaliação proporcionado ao professor e ao aluno. Existem diferentes técnicas de ensino utilizadas na Internet, algumas dessas continuam sendo projetadas com o uso de metodologias tradicionais de desenvolvimento, outras têm a capacidade de modelar de forma integrada e consistente alguns aspectos necessários para uma aplicação WEB. Para alcançar o objetivo proposto, foram realizadas pesquisas nas várias áreas abrangidas pelo tema em evidência, tanto relativo ao processo tradicional (aplicação de prova utilizando metodologia tradicional), como o desenvolvimento de software mediado por computador e uso da Internet em si. A modelagem de desenvolvimento para Internet deve integrar características de técnicas de projeto de sistemas de hipermídia devido à natureza hipertextual da Internet. O uso de hiperdocumento como autômatos com saída está na forma básica de representação de hipertexto, em que cada fragmento de informação é associado a um nodo ou a um link (estado/transições) do grafo. Sendo assim, os arcos direcionados representam relacionamentos entre os nodos ou links, ou seja, uma passagem do nodo origem para o nodo destino. As n-uplas dos autômatos apresentam uma correspondência as estruturas de hiperdocumentos na WEB, seu estado/transição inicial corresponde a sua primeira página e suas transições definidas na função programa, funcionam como ligações lógicas, quando selecionadas durante a navegação do hipertexto. Entretanto, faz-se necessário um levantamento dos modelos de hipertextos e das ferramentas de implementação disponíveis para a Internet, a fim de que seja capaz de suportar as peculiaridades do ambiente. Tudo isso deve ser integrado preferencialmente em um paradigma de desenvolvimento amplamente aceito, para que os projetistas não tenham muitas dificuldades em assimilar os conceitos propostos. A proposta apresentada nesta dissertação, batizada de Hyper-Automaton (hipertexto e autômato), consiste na integração de um Curso na WEB, utilizando formalismo de Autômatos Finitos com Saída para a modelagem dos conceitos necessários e definição das fases adequadas para completar a especificação de Sistema Exercício e Avaliação, bem como a especificação da Geração Automática dos Exercícios e Avaliações baseadas em autômatos para a WEB. Os modelos criados abrangem conceitos de Máquina de Mealy, Máquina de Moore e Aplicações de Hiperdocumentos e Ferramentas de Programação para Internet, os mesmos já testados em caso real. Os parâmetros apurados, nos testes, serviram a uma seqüência de etapas importantes para modelar e complementar a especificação do sistema projetado. Com os parâmetros e etapas de modelagem, a metodologia Hyper-Automaton consegue integrar, de forma consistente, as vantagens de várias técnicas específicas de modelagem de documentos e sistemas de hipermídia. Essas vantagens, aliadas ao suporte às ferramentas de desenvolvimento para Internet, garantem que a metodologia fique adequada para a modelagem de Sistemas com aplicação de métodos de autômatos para exercícios e avaliação na WEB.

XHA: eXtensible Hyper-Automation

O objetivo geral desta dissertação é estudar as possibilidades de flexibilização da função de saída do Sistema Hyper-Automaton além das rígidas possibilidades utilizadas atualmente com a utilização direta do HTML, objetivando eliminar as limitações como execução de aplicações proprietárias, caracteres incompatíveis entre browsers, excesso de tráfego na rede, padronizar aplicações, incrementar recursos didáticos, melhorar o suporte a aplicações multimídia atuais e futuras, facilitar a manutenção, implementação e reuso, alterar o layout de saída no browser de maneira dinâmica, explorar outros recursos de links, estabelecer padrões de organização do material instrucional criado pelo professor e muitas outras. Tal sistema anteriormente desenvolvido e funcionando adequadamente, é baseado no formalismo de Autômatos Finitos com Saída como modelo estrutural para organização de hiperdocumentos instrucionais, em especial em cursos na Web, tornando o material hipermídia independente do controle da aplicação. O Sistema Hyper-Automaton, tornou-se portanto, um sistema semi-automatizado para suporte a cursos na Web. Com o desdobramento da pesquisa, esta procurou ir mais além e descreveu possibilidades de não só estudar os aspectos possíveis de formatação de saída do sistema, mas reestruturá-lo totalmente sobre uma linguagem de markup padrão, buscando atualizá-lo tecnologicamente definindo outras possibilidades para que significativos trabalhos futuros possam de maneira mais clara serem alcançados. Dessa maneira, esta dissertação centra-se no estudo da aplicação de formas de flexibilização do Sistema Hyper-Automaton, tanto na parte da estruturação de documentos que são conteúdos instrucionais armazenados, bem como, na forma desse material tornar-se-á disponível através de navegadores WWW compatíveis com as tecnologias propostas, possibilitando o incremento substancial de funcionalidades necessárias para cursos onde a Web é o principal meio. Esta pesquisa dá prosseguimento a dois trabalhos anteriormente concluídos no PPGC e do Curso de Bacharelado em Ciência da Computação da UFRGS no ano de 2000, na seqüência, Hyper-Automaton: Hipertextos e Cursos na Web Utilizando Autômatos Finitos com Saída, dissertação de mestrado de Júlio Henrique de A. P. Machado e Hyper-Automaton: Implementação e Uso, trabalho de diplomação de Leonardo Penczek.