310,555 research outputs found
Finkelstein-Rubinstein constraints for the Skyrme model with pion masses
No full textThe Skyrme model is a classical field theory modelling the strong interaction between atomic nuclei. It has to be quantized in order to compare it to nuclear physics. When the Skyrme model is semi-classically quantized it is important to take the Finkelstein-Rubinstein constraints into account. Recently, a simple formula has been derived to calculate the these constraints for Skyrmions which are well-approximated by rational maps. However, if a pion mass term is included in the model, Skyrmions of sufficiently large baryon number are no longer well-approximated by the rational map ansatz. This paper addresses the question how to calculate Finkelstein-Rubinstein constraints for Skyrme configurations which are only known numerically
Mixed moments of characteristic polynomials of random unitary matrices
No full textFollowing the work of Conrey, Rubinstein and Snaith and Forrester and Witte we examine a mixed moment of the characteristic polynomial and its derivative for matrices from the unitary group (also known as the CUE) and relate the moment to the solution of a Painlev{\'e} differential equation. We also calculate a simple form for the asymptotic behaviour of moments of logarithmic derivatives of these characteristic polynomials evaluated near the unit circle
The Grin of Schrödinger's Cat; Quantum Photography and the limits of Representation
No full textThe famous quantum physics experiment 'Schrödinger's cat' suggests that some situations are undecidable, i.e. they exist outside of the normative distinctions between 'truth' and 'false' because both states can co-exist under certain conditions. This paper suggests that photography has very close links with this state of affairs, because photography allows one to move from the world of certainty into the quantum dimension of undecidability and indeterminate states
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Síndrome de Rubinstein-Taybi, genética e clínica: uma revisão integrativa: Rubinstein-Taybi syndrome, genetic and clinic: an integrative review
No full textIntrodução: A Síndrome de Rubinstein-Taybi é uma doença genética rara, com amplo espectro fenotípico. É conhecida classicamente por sua alteração nos genes CREBBP e EP300 e clinicamente, pelo atraso intelectual, microcefalia, fácies típica, hálux alargado e alterações cognitivas. Entretanto, há uma variedade de quadros clínicos e genéticos muito ampla e pouco difundidas, o que dificulta o diagnóstico. Nesse sentido, esta revisão tem o objetivo de apresentar os diversos achados clínicos e facilitar o diagnóstico. Além disso, expõe os aspectos genéticos e a mutação mais frequente encontrada. Metodologia: foi realizada uma revisão integrativa, com o método PRISMA, com o intuito de demonstrar os principais aspectos genéticos e clínicos da síndrome de Rubinstein-Taybi, com a seleção final de 25 artigos. Resultados: foi observada uma clínica muito variada, com destaque para alterações não citadas no quadro clínico clássico e complicações em diversos sistemas. Na parte genética, foi encontrada maior mutação no gene CREBBP em relação ao EP300. Discussão: não foi possível relacionar o quadro genético com os fenótipos de forma muito específica
Exportações de carne bovina e infraestrutura de transporte rodoviária e portuária de 2001 a 2009: uma abordagem gravitacional
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Sócio-Econômico, Programa de Pós-Graduação em Economia, Florianópolis, 2011Para investigar a exportação de carne bovina das microrregiões brasileira a pesquisa utiliza o modelo gravitacional aumentado com correção de amostra e empresas heterogêneas de Helpman, Melitz e Rubinstein, 2008, (HMR), para somente uma commodity. A partir dos dados de exportação de 43 microrregiões, pelos portos de Paranaguá, Santos e Itajaí para Europa Ocidental, Leste Europeu e Oriente médio entre os anos de 2001 a 2009, montou-se um painel com 3.843 observações. Os coeficientes obtidos mostraram que tempo, custo e quantidade movimentada de contêineres nos portos são barreiras relevantes para as exportações brasileiras, assim como a infraestrutura rodoviária. Ademais, com investimentos devidamente planejados na ordem de R140 milhões em comércio de carne.To investigate the exportation of Brazilian micro-region#s beef (cattle meat) the study used the augmented gravity model with sample correction and heterogeneous firms of Helpman, Melitz and Rubinstein, 2008, (HMR), for only one commodity. Using a data from the exports of 43 micro-regions to the ports of Paranaguá, Santos and Itajaí to Western Europe, Eastern Europe and the Middle East between the years 2001 to 2009, a panel was set up with 3.843 observations. The coefficients showed that time, ship-in costs and quantity of containers traded in ports are important barriers to Brazilian exports as well as road infrastructure. Moreover properly planned investments of around R 140 million in meat trade
Artur Rubinstein
No full textThis poster celebrating Arther Rubinstein features a black and white illustration of piano keys, some of which are pressed down, on a black background.piano keys on a black backgroun
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Quantum Earth mover's distance, No-go Quantum Kantorovich-Rubinstein theorem, and Quantum Marginal Problem
No full textThe earth mover's distance is a measure of the distance between two
probabilistic measures. It plays a fundamental role in mathematics and computer
science. The Kantorovich-Rubinstein theorem provides a formula for the earth
mover's distance on the space of regular probability Borel measures on a
compact metric space. In this paper, we investigate the quantum earth mover's
distance. We show a no-go Kantorovich-Rubinstein theorem in the quantum
setting. More precisely, we show that the trace distance between two quantum
states can not be determined by their earth mover's distance. The technique
here is to track the bipartite quantum marginal problem. Then we provide
inequality to describe the structure of quantum coupling, which can be regarded
as quantum generalization of Kantorovich-Rubinstein theorem. After that, we
generalize it to obtain into the tripartite version, and build a new class of
necessary criteria for the tripartite marginal problem.Comment: arXiv admin note: text overlap with arXiv:quant-ph/0506138 by other
author
Rubinstein-Taybi Syndrome: physical anomalies, clinical and audiologic evaluation
No full textINTRODUÇÃO: A Síndrome de Rubinstein-Taybi foi descrita pela primeira vez em 1963, após a observação dos traços físicos semelhantes apresentados por sete crianças com retardo mental, baixa estatura, polegares grandes e largos e anomalias faciais. Mais tarde, novas publicações definiram outras características dessa síndrome, a qual incide em 1 a cada 300.000 nascidos e apresenta etiologia incerta. Sintomas otorrinolaringológicos e fonoaudiológicos são freqüentes, daí a importância de melhor conhecimento dessa síndrome por esses especialistas. RELATO DE CASO: Apresentamos as principais manifestações clínicas, traços físicos e as avaliações auditivas de cinco crianças portadoras da Síndrome de Rubinstein-Taybi, em atendimento na Faculdade de Medicina de Botucatu (UNESP). Para as avaliações auditivas foram realizados exames de audiometria tonal, imitanciometria e potenciais evocados do tronco encefálico (BERA). As principais características observadas foram: retardo mental, baixa estatura, polegares largos, pirâmide nasal alta, palato ogival, má oclusão dentária, atraso no desenvolvimento neuropsicomotor e de linguagem. DISCUSSÃO: Os traços físicos característicos dos portadores dessa síndrome facilitam o diagnóstico, e muitos deles são responsáveis por sintomas otorrinolaringológicos e fonoaudiológicos, como infeções de vias aéreas superiores, obstrução nasal, otites médias, hipertrofia adenoamigdaliana, surdez condutiva, hipotonia perioral e disfagia. O importante comprometimento cognitivo é responsável pelo atraso no desenvolvimento da linguagem e pelo baixo rendimento escolar. CONCLUSÕES: Frente às várias manifestações otorrinolaringológicas e fonoaudiológicas apresentadas pelas crianças portadoras da Síndrome de Rubinstein-Taybi, torna-se necessário que esses especialistas conheçam melhor essa síndrome para que possam fazer o diagnóstico precoce e orientar o tratamento dessas crianças.INTRODUCTION: The Rubinstein-Taybi Syndrome was first described in 1963 when the authors presented seven children with mental and growth retardation, broad thumbs and big toes, associated to face anomalies. Years later new publications characterized other physical anomalies. The incidence in the general population is one in 300.000 borns and the aetiology is unknown until now. The purpose of this study was to present the clinical manifestations, physical anomalies and the audiologic evaluation of five children with Rubinstein-Taybi Syndrome. REPORT of CASES: Five children with Rubinstein-Taybi Syndrome were evaluated by main clinical manifestations, physical anomalies and audiologic evaluation. The main clinical and physical manifestations were: mental retardation, short stature, short and broad fingers, beaked nose, high palate, irregular placement of teeth and poor speech development. The auditory acuity was evaluated by tonal audiometry, tympanometry and auditory brainstem response (ABR). DISCUSSION: The physical characteristics presented by the patients with Rubinstein-Taybi Syndrome facilitate the diagnosis and are responsible for otolaryngological and phonoaudiological symptoms, like airway infections, nasal obstruction, otitis media, tonsillar hyperplasia, deafness, perioral hypotonia and dysphagia. The cognitive impairment is responsible to speech delay and learning disabilities. CONCLUSION: The presence of otolaryngologic and phonoaudiologic symptoms in patients with Rubinstein-Taybi Syndrome permit specialists to make early diagnoses and treatment.UNESP Faculdade de Medicina de BotucatuUNESP Faculdade de Medicina de Botucat
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