The radiation of a uniformly accelerated charge is beyond the horizon: a simple derivation

We show, by exploring some elementary consequences of the covariance of Maxwell's equations under general coordinate transformations, that, despite inertial observers can indeed detect electromagnetic radiation emitted from a uniformly accelerated charge, comoving observers will see only a static electric field. This simple analysis can help understanding one of the most celebrated paradoxes of last century.Comment: Revtex, 6 pages, 2 figures. v2: Some small corrections. v3: Citation of a earlier paper included. v4: Some stylistic changes. v5: Final version to appear in AJ

Hemolytic vascular inflammation: an update

Made available in DSpace on 2016-11-10T13:31:43Z (GMT). No. of bitstreams: 1 pmed_26969775.pdf: 607909 bytes, checksum: c33e900140de01738d42c6807067a943 (MD5) Previous issue date: 201638555

Gaining land and gaining ground? The Popular Agrarian Reform by the Landless Rural Workers’ Movement (MST) in Brazil

The Landless Rural Workers' Movement (MST), one of the most important movements in Brazil, known for its land occupations, recently launched proposals to implement a new Popular Agrarian Reform (PAR) project. Consequently, one must ask: is there need for agrarian reform (AR) in Brazil? This question must engage with another discussion, that of the development of capitalism in the countryside and its consequences for the peasantry - the agrarian question (AQ). Its contemporary relevance is a matter of debate, and agrarian populism has gained traction in academic and popular discourse. PAR must be situated within these debates, as a response to processes of agrarian change. The aim of this qualitative case study was to understand how MST reads the AQ and constructs such response. Fieldwork was conducted in Southern Brazil in January-February 2015. Findings indicate that PAR reflects the understanding of a new AQ by MST. I argue that PAR was partly born due to an MST dilemma: frustration regarding possibilities of redistributive AR; de-legitimization of previous land occupation claims; MST’s de-territorialization in settlements/camps and settlements’ individual character. PAR must be understood as a dispute of material and symbolic territories, a strategy to conquer land, keep it and gain ground

Compuestos fenólicos alimentarios y su relación con biomarcadores de inflamación en personas con enfermedades cardiometabólicas.

Introducción: Los compuestos polifenólicos poseen propiedades benéficas que podrían prevenir las enfermedades cardiometabólicas (ECM). Objetivo: Analizar la relación entre indicadores de inflamación, ingesta de compuestos fenólicos y factores de riesgo (FR) de enfermedades cardiometabólicas. Metodología: Estudio descriptivo, correlacional, de corte transversal. Participaron adultos (n=174) asistentes al Servicio de Cardiología del HNC. Se aplicaron: encuesta alimentaria validada, de actividad física y hábito tabáquico, toma de medidas antropométricas, presión arterial y determinaciones bioquímicas. Se utilizó el programa Interfood v.1.3 para analizar ingesta de polifenoles y alimentos fuente (AF), test de Fisher y Wilcoxon para analizar FR según sexo y test de Spearman para valorar relación entre ingesta de polifenoles, AF y FR. Resultados: El 83% presentó exceso de peso y 96% riesgo cardiovascular. HDL-c, colesterol y PCRus fueron diferentes según sexo (p<0,05). El consumo promedio de AF de compuestos fenólicos fue 637,97 ± 501,11 y 600,53 ± 422,81 g/día para hombres y mujeres, respectivamente. El consumo de AF de antocianos fue mayor en mujeres (p=0,04). Se encontró asociación inversa estadísticamente significativa entre: presión arterial diastólica (PAD) y flavanonas (r=-0,15, p=0,05); IMC y AF de antocianos (r= - 0,19, p=0,02); PA sistólica (PAS) y AF de flavanoles (r= -0,17, p=0,02) y PAS y AF de flavanonas (r= -0,17, p=0,03). Asociaciones positivas entre: PAD y flavonas (r=0,15, p=0,04); glucemia y flavonas (r=0,22, p=0,01); triglicéridos e isoflavonas (r=0,42, p=0,05); IMC y AF de flavanonas (r=0,19, p=0,01); glucemia y AF de flavonoles (r=0,19, p=0,03) y PCRus y AF flavonoles (r=0,29, p=0,02). Conclusión: Los compuestoS fenólicos se asociaron a indicadores de inflamación y de riesgo de ECM

Characterizing videos, audience and advertising in Youtube channels for kids

Online video services, messaging systems, games and social media services are tremendously popular among young people and children in many countries. Most of the digital services offered on the internet are advertising funded, which makes advertising ubiquitous in children's everyday life. To understand the impact of advertising-based digital services on children, we study the collective behavior of users of YouTube for kids channels and present the demographics of a large number of users. We collected data from 12,848 videos from 17 channels in US and UK and 24 channels in Brazil. The channels in English have been viewed more than 37 billion times. We also collected more than 14 million comments made by users. Based on a combination of text-analysis and face recognition tools, we show the presence of racial and gender biases in our large sample of users. We also identify children actively using YouTube, although the minimum age for using the service is 13 years in most countries. We provide comparisons of user behavior among the three countries, which represent large user populations in the global North and the global South

Integrated stress response of Escherichia coli to methylglyoxal : transcriptional readthrough from the nemRA operon enhances protection through increased expression of glyoxalase I

© 2013 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.Peer reviewedPublisher PD

Educação ambiental e unidades de conservação : a inclusão da população como alternativa de manejo do Parque Nacional de Brasília

Monografia (graduação)—Universidade de Brasília, Instituto de Humanidades, Departamento de Geografia, 2009.Localizado próximo a uma área urbana, o Parque Nacional de Brasília sofre pressões antrópicas que aumentam gradativamente junto com a expansão urbana. Além da ocupação desordenada do seu entorno, um dos grandes problemas enfrentados pelo parque são os comportamentos e os impactos das ações da população sobre a área. É de grande importância a Educação Ambiental dos freqüentadores do Parque, despertando neles o interesse pela área, a fim de incluindo-os no processo de preservação e conscientização ambiental, como forma de auxiliar no manejo desta Unidade de Conservação

Pair Interaction Scale: construction and evidence of validity for higher education students

As relações que os estudantes estabelecem com os pares são importantes para a aprendizagem e o desenvolvimento psicossocial e cognitivo. Diante disto, este estudo apresenta a construção e as evidências de validade da Escala de Interação com Pares para estudantes do ensino superior. Participaram da pesquisa 1070 universitários, com idade média de 23 anos (DP=6,5). A análise fatorial exploratória indicou uma estrutura multidimensional, composta pelos fatores: Interações Sociais, Interações Íntimas, Interações Acadêmicas pautadas no oferecimento de ajuda e Interações Acadêmicas com ênfase no recebimento de ajuda. A análise fatorial confirmatória destacou a adequação dos dados à estrutura fatorial (CFI=0,978; GFI=0,980; RMSEA=0,06). Os coeficientes de regressão dos itens junto aos fatores foram satisfatórios (0,55<ß<0,86) e os indicadores de consistência interna de cada fator são adequados (0,72< <0,85). Tais resultados sinalizam a existência de propriedades psicométricas aceitáveis e sugerem eficiência na utilização do instrumento.The relationships that students establish with pairs are important to their learning and to their psychosocial and cognitive development. In view of this, this study presents the construction and evidence of the validity of the Pair Interaction Scale for higher education students. 1070 university students with an average of 23 years of age (SD=6.5) participated in the research. The exploratory factor analysis indicated a multidimensional structure, composed of the factors: Social Interactions, Intimate Interactions, Academic Interactions related to offering help and Academic Interactions with emphasis on receiving help. The confirmatory factor analysis highlighted the suitability of the data to the factor structure (CFI=0.978; GFI=0.980; RMSEA=0.06). The regression coefficients of the items in relation to the factors were satisfactory (0.55<ß<0.86) and the indicators of internal consistency of each factor are suitable (0.72< <0.85). Such results signal the existence of acceptable psychometric parameters and efficiency in the utilization of the instrument is suggested.Editora Universitária São Francisc

Comparação do conteúdo entre: qualidade de vida e escalas de funcionalidade para a paraparesia espástica não-traumática de acordo com a Classificação Internacional de Funcionalidade, Incapacidade e Saúde

Objetivo: Identificar instrumentos utilizados para a avaliação funcional de pessoas com lesão medular não-traumática (LMNT) e comparar seu conteúdo de acordo com os conceitos da CIF. Método: A revisão sistemática foi realizada nas bases de dados Medline, Scielo, Pubmed e Bireme com os descritores “paraparesia espástica”, “avaliação funcional”, “exame neurológico”, “escalas neurológicas”, “avaliação neurológica” e “medidas de avaliação neurológica”. Para encontrar artigos relatando as escalas de avaliação funcional aplicadas em indivíduos com LMNT. O conteúdo de tais instrumentos foi comparado após vinculá-los à CIF. Resultados: A revisão sistemática identificou 12 instrumentos de avaliação funcional de LMNT, foram identificadas 153descrições das categorias da CIF, concentradas principalmente em: funções neuromusculoesqueléticas, digestivas, atividades motoras e autocuidado. Entre os fatores ambientais: a tecnologia assistiva para mobilidade, para uso pessoal na vida cotidiana, mereceu maior atenção. Conclusão: Este estudo forneceu um guia para identificar instrumentos para avaliar a funcionalidade de indivíduos com LMNT. &nbsp; &nbsp;Purpose: Identify instruments used for the functional evaluation of people with Non-traumatic Spinal Cord Injury (NTSP), and compare their contents according to ICF concepts. Method: Literature review was conducted in the Medline, Scielo, Pubmed, and Bireme databases with the descriptors “spastic paraparesis,” “functional evaluation,” “neurological examination,” “neurological scales,” “neurological evaluation,” and “neurological evaluation measurements,” to find articles reporting the functional evaluation scales having been applied on individuals with NTSP. The content of such instruments was compared after linking them to ICF. Results: The systematic review identified 12 instruments for functional evaluation instruments of NTSP, in we described 153 ICF categories, concentrated mainly in: neuromusculoskeletal functions, digestive, motor activities, and self-care. Among the environmental factors: assistive technology for mobility, to personal use in daily life deserved greater attention. Conclusion: This study provided a guide to identify instruments to evaluate the functionality of individuals with NTSP