Mathematical retroreflectors

Retroreflectors are optical devices that reverse the direction of incident beams of light. Here we present a collection of billiard type retroreflectors consisting of four objects; three of them are asymptotically perfect retroreflectors, and the fourth one is a retroreflector which is very close to perfect. Three objects of the collection have recently been discovered and published or submitted for publication. The fourth object - notched angle - is a new one; a proof of its retroreflectivity is given.Comment: 32 pages, 19 figure

Osteomielite Crónica em Lactente

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Automatic monitoring and control of museums’ environment based on Wireless Sensor Networks

In museums, it is critical to properly conserve the existing artwork. For this purpose, it is fundamental to continuously monitor its environment, either in storage or exhibition rooms. Contrarily to traditional measuring equipments and procedures used in museums, the deployment of a Wireless Sensor Network (WSN) can help to implement these measurements continuously, in a real-time basis, and in a much easier and cheaper way. This is the main objective of the WISE-MUSE project, which proposes the use of WSNs for museums’ environmental and structural monitoring, and automatic environmental control. In this paper, the implementation and the main results of the WISE-MUSE project, which was carried out in a contemporary art museum, are described. Among other important contributions that will also be described in this paper, the development of a new wireless sensor node and a Web-based visualization tool, which bring some considerable advantages when compared with other commercially available solutions, are emphasized.info:eu-repo/semantics/publishedVersio

A Osteomielite Crónica pode ser o Precedente de uma Infeção por Corynebacterium Diphtheriae

INTRODUÇÃO E OBJETIVOS: A infeção por Corynebacterium diphtheriae não toxinogénica tem sido cada vez mais descrita e associada a doença grave e disseminada, como endocardite, artrite séptica e osteomielite1, podendo estar associada a doentes com infeções ósseas ou ar6culares, entre outras. 2 A vacinação não é protetora para C. diphtheriae não toxinogénica. 3 Apresentamos o caso clínico de uma doente com fractura exposta do úmero com 1 ano de evolução com sinais de osteomielite crónica e isolamento de C. diphtheriae, S. aureus e S. pyogenes. CASO CLÍNICO: Rapariga de 11 anos Natural e residente na Guiné Desconhece-se estado vacinal. Desconhece-se contexto epidemiológico. Foi fieto: DESBRIDAMENTO e fistulectomia FLUCLOXACILINA e RIFAMPICINA 12semanas + PENICILINA 3 semanas; boa evolução aos 3 meses. CONCLUSÃO: A difteria cutânea é causada por estirpes de Corynebacterium diphteriae, produtoras ou não de toxina. Caracterizam-se por úlceras cutâneas crónicas, que servem como reservatório. A probabilidade de envolvimento faríngeo é rara. É possível, que possa ter algum papel como agente patogénico na osteomielite crónica, em co-infeção com S. aureus2, tal como no caso apresentado.info:eu-repo/semantics/publishedVersio

Valores como predictores de satisfacción con la vida en los jóvenes

Numa perspectiva funcionalista, os valores são uma expressão cognitiva das necessidades humanas, princípios que orientam o comportamento para metas mais pessoais, sociais ou gerais de vida, cujo impacto psicossocial merece mais investigação. Neste estudo, analisou-se em que medida o tipo de orientação dos valores prediz a satisfação com a vida de 562 jovens portugueses (n = 303, 53,9% mulheres), com idades entre 14 e 22 anos (M = 16,9, DP = 1,71), que frequentam o ensino médio: via profissionalizante (63,7%) e regular (36,3%). Os jovens completaram o Questionário de Valores Básicos e a Escala de Satisfação com a Vida. Os resultados da análise de regressão linear indicam que a orientação dos valores explica menos de um quarto da variabilidade da satisfação com a vida, o que suscita a necessidade de se analisar o seu poder explicativo em conjunto com outras variáveis, por exemplo, de personalidade e sociocognitivas.In a functionalist perspective, values are a cognitive expression of human needs as well as principles that guide behaviors to personal, social or general life goals, whose psychosocial impact deserves more investigation. This study aimed to analyze whether the type of values orientation predicts life satisfaction in 562 Portuguese youths (n = 303, 53.9% women) aged 14 to 22 years (M = 16.9; SD = 1.71), attending high school studies, being 63.7% technical and (36.3%) regular high school.Students completed the Basic Values Survey and the Satisfaction With Life Scale. The results of the linear regression analyzes indicate that the values orientation explains less than a quarter of life satisfaction variability, which indicated the need to further analyze its explanatory power together with other variables, such as, personality and socio-cognitive.Desde el punto de vista funcional, los valores son una expresión cognitiva de las necesidades humanas, principios que orientan el comportamiento hacia metas más personales, sociales o generales de vida, cuyo impacto psicosocial necesita más investigación. En este estudio se analizó en qué medida el tipo de orientación de los valores predice la satisfacción con la vida de 562 jóvenes portugueses (n = 303, 53.9% mujeres), con edades entre 14 y 22 años ( = 16.9, P = 1.71) que frecuentan Enseñanza Secundaria: profesional (63.7%) y normal (36.3%). Los jóvenes completaron el Cuestionario de Valores Básicos y la Escala de Satisfacción con la Vida. Los resultados del análisis de regresión lineal indican que la orientación de los valores explica menos de una cuarta parte de la variabilidad de satisfacción con la vida, lo que plantea la necesidad de analizar su poder explicativo, junto con otras variables, por ejemplo, de personalidad y socio-cognitivas.(undefined)info:eu-repo/semantics/publishedVersio

Cognitive Impairment and Magnetic Resonance Imaging Correlates in Primary Progressive Multiple Sclerosis

Objectives: To characterize cognitive impairment in primary progressive multiple sclerosis (PPMS) and to correlate the pattern of cognitive deficits with brain magnetic resonance imaging (MRI) volumetric data. Materials and methods: In a multicenter cross-sectional study, we recruited consecutive patients with PPMS as well as age, sex, and education level-matched healthy controls (HC). All participants underwent neuropsychological (NP) assessment, and brain MRI was performed in patients with PPMS for analysis of lesion load, subcortical GM volumes, and regional cortical volumes. Results: We recruited 55 patients with PPMS and 36 HC. Thirty-six patients were included in the MRI analysis. Patients with PPMS performed significantly worse than HC in all NP tests. Subcortical GM volume was significantly correlated with all NP tests, except for Stroop Test, with the largest effect for the thalamus (r=-.516 [BVMT-R DR, P=.016 FDR-corrected] to r=.664 [SDMT, P<.001 FDR-corrected]). In the stepwise linear regression model, thalamic volume was the only predictor of performance in all NP tests. Conclusion: Cognitive impairment is common in PPMS and affects all evaluated cognitive domains. Subcortical GM volume, particularly of the thalamus, is a strong predictor of cognitive performance, suggesting it has a central role in the pathophysiology of PPMS-related cognitive dysfunction.info:eu-repo/semantics/publishedVersio

Active Galactic Nuclei under the scrutiny of CTA

Active Galactic Nuclei (hereafter AGN) produce powerful outflows which offer excellent conditions for efficient particle acceleration in internal and external shocks, turbulence, and magnetic reconnection events. The jets as well as particle accelerating regions close to the supermassive black holes (hereafter SMBH) at the intersection of plasma inflows and outflows, can produce readily detectable very high energy gamma-ray emission. As of now, more than 45 AGN including 41 blazars and 4 radiogalaxies have been detected by the present ground-based gamma-ray telescopes, which represents more than one third of the cosmic sources detected so far in the VHE gamma-ray regime. The future Cherenkov Telescope Array (CTA) should boost the sample of AGN detected in the VHE range by about one order of magnitude, shedding new light on AGN population studies, and AGN classification and unification schemes. CTA will be a unique tool to scrutinize the extreme high-energy tail of accelerated particles in SMBH environments, to revisit the central engines and their associated relativistic jets, and to study the particle acceleration and emission mechanisms, particularly exploring the missing link between accretion physics, SMBH magnetospheres and jet formation. Monitoring of distant AGN will be an extremely rewarding observing program which will inform us about the inner workings and evolution of AGN. Furthermore these AGN are bright beacons of gamma-rays which will allow us to constrain the extragalactic infrared and optical backgrounds as well as the intergalactic magnetic field, and will enable tests of quantum gravity and other "exotic" phenomena.Comment: 28 pages, 23 figure