2,149 research outputs found

    Cavity-enhanced optical detection of carbon nanotube Brownian motion

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    Optical cavities with small mode volume are well-suited to detect the vibration of sub-wavelength sized objects. Here we employ a fiber-based, high-finesse optical microcavity to detect the Brownian motion of a freely suspended carbon nanotube at room temperature under vacuum. The optical detection resolves deflections of the oscillating tube down to 50pm/Hz^1/2. A full vibrational spectrum of the carbon nanotube is obtained and confirmed by characterization of the same device in a scanning electron microscope. Our work successfully extends the principles of high-sensitivity optomechanical detection to molecular scale nanomechanical systems.Comment: 14 pages, 11 figure

    Adherence in Rheumatoid Arthritis patients assessed with a validated Italian version of the 5-item compliance questionnaire for rheumatology

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    OBJECTIVES: The 5-item Compliance Questionnaire for Rheumatology (CQR5) proved reliability and validity in respect of identification of patients likely to be high adherers (HAs) to anti-rheumatic treatment, or low adherers (LAs), i.e. taking<80% of their medications correctly. The objective of the study was to validate an Italian version of CQR5 (I-CQR5) in rheumatoid arthritis (RA) patients and to investigate factors associated with high adherence. METHODS: RA patients, undergoing treatment with ≥1 self-administered conventional synthetic disease-modifying anti-rheumatic drug (csDMARD) or biological DMARD (bDMARD), were enrolled. The cross-cultural adaptation and validation of I-CQR5 followed standardised guidelines. I-CQR5 was completed by patients on one occasion. Data were subjected to factor analysis and Partial Credit model Parametrisation (PCM) to assess construct validity of I-CQR5. Analysis of factors associated with high adherence included demographic, social, clinical and treatment information. Factors achieving a p<0.10 in univariate analysis were included in multivariable analysis. RESULTS: Among 604 RA patients, 274 patients were included in the validation and 328 in the analysis of factors associated with adherence. Factor analysis and PCM confirmed the construct validity and consistency of I-CQR5. HAs were found to be 109 (35.2%) of the patients. bDMARD treatment and employment were found to be independently associated with high adherence: OR 2.88 (1.36-6.1), p=0.006 and OR 2.36 (1.21-4.62), p=0.012, respectively. CONCLUSIONS: Only one-third of RA patients were HAs according to I-CQR5. bDMARDs and employment status increased by almost 3-fold the likelihood of being highly adherent to the anti-rheumatic treatment.Peer reviewe

    Scenic and Recreational River Designation: What Happened to the James?

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    In 1976, the South Dakota Department of Game , Fish and Parks (DGFP) sponsored the nomination of the upper James River as a state scenic and recreational river. The nomination failed to receive legislative approval in the 1977 and 1978 state legislative sessions. A case analysis of this nomination and the failure to approve it is provided in this publication. The major participants are identified, and their �· relationships with each other and how they fared are examined. This gives an understanding of why and how the actors react to the rules in a water allocation process and an overview of the designation process. The case study also provides a historical perspective on one designation process, serving as a basis for future public considerations of changes in the river designation process

    Monitoramento da qualidade da água de represas e avaliação de riscos aos sistemas de irrigação

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    A construção de barragens é uma alternativa para aumentar a disponibilidade dos recursos hídricos visando atender as necessidades humanas. No norte do Espírito Santo essa técnica é muito utilizada no armazenamento de água para uso na irrigação, e tem crescido em função dos longos períodos de estiagem. No entanto a quantidade e qualidade das águas dessas barragens podem variar e comprometer seu uso na irrigação. Deste modo, objetivou-se com este trabalho estudar variáveis físico-químicas e hidroquímicas da água em represas recém-construídas, e outras já existentes, no norte do Espírito Santo, para identificação de possíveis riscos aos sistemas de irrigação. O monitoramento foi realizado, ao longo de 14 meses, em 4 represas em Nova Venécia-ES (P1 a P4) e outras 4 represas no município de São Mateus-ES (P5 a P8). As variáveis hidroquímicas analisadas foram pH, temperatura, oxigênio dissolvido (OD), condutividade elétrica (CE), sólidos totais (ST), turbidez, ferro total (FeT), Fe2+, e Fe3+, ortofosfato (PO43-), sulfato (SO43-), sódio (Na+), potássio (K+), cálcio (Ca+), magnésio (Mg2+), dureza, alcalinidade (HCO3-) e cloreto (Cl-). Além disso, dados de nível de água das represas, regime de chuva e evapotranspiração foram obtidos. Os dados foram avaliados através de estatística descritiva (máximo, mínimo, média e desvio padrão), de acordo com a classe de risco de danos ao sistema de irrigação e com os diagramas de Piper e de classificação de águas para irrigação. As elevadas concentrações de ferro e sólidos totais registradas nas águas das represas, tanto de Nova Venécia, quanto de São Mateus, geralmente com maiores valores nas represas novas, inviabilizam o uso direto destas águas na irrigação por gotejamento. Nestes casos, o tratamento da água é indispensável e possibilita seu uso com redução de possíveis danos ao sistema de irrigação, assim os irrigantes devem estar atentos ao uso de filtros, aeradores e decantadores para impedir a passagem destes elementos, impedindo a deposição ao longo do sistema de irrigação. Para os demais parâmetros estudados a maioria das amostras apresentou resultados aceitáveis. As represas de Nova Venécia e São Mateus apresentaram suas águas majoritariamente em classes C1S1, de baixa salinidade e, portanto, de adequada qualidade para irrigação. Poucas amostras foram enquadradas na classe C2S2, em algumas épocas, neste caso essas águas devem ser utilizadas em solos de boa permeabilidade e com certo grau de lixiviação e optar por plantas mais tolerantes. Quanto a classificação hidroquímica das águas de ambos municípios, foram majoritariamente sódicas cloretadas, com pequenas variações composicionais sazonais

    Kernels for Grassmann flops

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    We develop a generalization of the QQ-construction of the first author, Diemer, and the third author for Grassmann flips. This generalization provides a canonical idempotent kernel on the derived category of the associated global quotient stack. The idempotent kernel, after restriction, induces a semi-orthogonal decomposition which compares the flipped varieties. Furthermore its image, after restriction to the geometric invariant theory semistable locus, "opens" a canonical "window" in the derived category of the quotient stack. We check this window coincides with the set of representations used by Kapranov to form a full exceptional collection on Grassmannians

    Giant optical anisotropy in a single InAs quantum dot in a very dilute quantum-dot ensemble

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    We present the experimental evidence of giant optical anisotropy in single InAs quantum dots. Polarization-resolved photoluminescence spectroscopy reveals a linear polarization ratio with huge fluctuations, from one quantum dot to another, in sign and in magnitude with absolute values up to 82%. Systematic measurements on hundreds of quantum dots coming from two different laboratories demonstrate that the giant optical anisotropy is an intrinsic feature of dilute quantum-dot arrays.Comment: submitted to Applied Physics Letter

    Gli statistici italiani e la "questione della razza"

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    Ricostruzione del contributo di statistici e demografi alla preparazione dei provvedimenti discriminatori del 1938 e degli effetti di questi sull'articolazione accademica e scientifica della disciplina
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