1,386 research outputs found

    Government Information Quarterly. Volume 7, no. 2: National Aeronautics and Space Administration Scientific and Technical Information Programs. Special issue

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    NASA scientific and technical information (STI) programs are discussed. Topics include management of information in a research and development agency, the new space and Earth science information systems at NASA's archive, scientific and technical information management, and technology transfer of NASA aerospace technology to other industries

    [NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 2:] External Information Sources and aerospace R&D: The use and importance of technical reports by US aerospace engineers and scientists

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    This paper formulates and studies two propositions. Proposition 1 states that information that is external to the aerospace organization tends to be used less than internal sources of information; the more geographically removed the information is from the organization, the less likely it is to be used. Proposition 2 states that of the various sociometric variables assumed to influence the use of an information channel or source, perceived accessibility exerts the greatest influence. Preliminary analysis based on surveys supports Proposition 1. This analysis does not support Proposition 2, however. Evidence here indicates that reliability and relevance influence the use of an information source more than the idea of perceived accessibility

    A review and evaluation of the Langley Research Center's Scientific and Technical Information Program: Results of phase 6: The technical report. A survey and analysis

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    Current practice and usage using selected technical reports; literature relative to the sequential, language, and presentation components of technical reports; and NASA technical report publications standards are discussed. The effctiveness of the technical report as a product for information dissemination is considered

    NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 24: A general approach to measuring the value of aerospace information products and services

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    This paper discusses the various approaches to measuring the value of information, first defining the meanings of information, economics of information, and value. It concludes that no general model of measuring the value of information is possible and that the usual approaches, such as cost/benefit equations, have very limited applications. It also concludes that in specific contexts with given goals for newly developed products and services or newly acquired information there is a basis for its objective valuation. The axioms and inputs for such a model are described and directions for further verification and analysis are proposed

    Weyl invariance, non-compact duality and conformal higher-derivative sigma models

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    We study a system of nn Abelian vector fields coupled to 12n(n+1)\frac 12 n(n+1) complex scalars parametrising the Hermitian symmetric space Sp(2n,R)/U(n)\mathsf{Sp}(2n, {\mathbb R})/ \mathsf{U}(n). This model is Weyl invariant and possesses the maximal non-compact duality group Sp(2n,R)\mathsf{Sp}(2n, {\mathbb R}). Although both symmetries are anomalous in the quantum theory, they should be respected by the logarithmic divergent term (the ``induced action'') of the effective action obtained by integrating out the vector fields. We compute this induced action and demonstrate its Weyl and Sp(2n,R)\mathsf{Sp}(2n, {\mathbb R}) invariance. The resulting conformal higher-derivative σ\sigma-model on Sp(2n,R)/U(n)\mathsf{Sp}(2n, {\mathbb R})/ \mathsf{U}(n) is generalised to the cases where the fields take their values in (i) an arbitrary K\"ahler space; and (ii) an arbitrary Riemannian manifold. In both cases, the σ\sigma-model Lagrangian generates a Weyl anomaly satisfying the Wess-Zumino consistency condition.Comment: 24 page

    Diagnosis and treatment of upper eyelid lipoma: A case report

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    Purpose: Presentation of a rare lesion: a case of upper eyelid lipoma, Observations: A 76-year-old otherwise healthy woman presented with a right upper eyelid swelling. Her medical history was recorded. On ophthalmologic examination a soft, non-ulcerated and not well-circumscribed mass was evident. An ultrasonography examination was carried out showing a hyperechoic non capsulated mass situated between the superior orbital margin and the orbicularis oculi muscle. Conclusions and Importance: Eyelid lipomas must be differentiated from herniated orbital fat, cystic lesions, tumours, and the lacrimal gland. A pre-operative differential diagnosis of eyelid lipoma can be done through medical history, ophthalmologic, and ultrasonography examinations. Nevertheless, in case of doubt a magnetic resonance imaging (MRI) should be performed to assess a possible orbital involvement and to plan for the right surgical procedure to be performed

    NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 48: Valuing information in an interactive environment

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    Consideration effort has been devoted over the past 30 years to developing methods and means of assessing the value of information. Two approaches - value in exchange and value in use - dominate; however, neither approach enjoys much practical application because validation schema for decision-making is missing. The approaches fail to measure objectively the real costs of acquiring information and the real benefits that information will yield. Moreover, these approaches collectively fail to provide economic justification to build and/or continue to support an information product or service. In addition, the impact of Cyberspace adds a new dimension to the problem. A new paradigm is required to make economic sense in this revolutionary information environment. In previous work, the authors explored the various approaches to measuring the value of information and concluded that, in large measure, these methods were unworkable concepts and constructs. Instead, they proposed several axioms for valuing information. Most particularly they concluded that the 'value of information cannot be measured in the absence of a specific task, objective, or goal.' This paper builds on those axioms and describes under which circumstances information can be measured in objective and actionable terms. This paper also proposes a methodology for undertaking such measures and validating the results

    The Arab American experience with diabetes: Perceptions, myths and implications for culturally-specific interventions

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    Culturally-specific lifestyle diabetes prevention programs require an assessment of population disease perceptions and cultural influences on health beliefs and behaviors. The primary objectives were to assess Arab Americans’ knowledge and perceptions of diabetes and their preferences for a lifestyle intervention

    Idiopathic calcium nephrolithiasis with pure calcium oxalate composition: clinical correlates of the calcium oxalate dihydrate/monohydrate (COD/COM) stone ratio

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    Pure calcium oxalate is the most frequent type of idiopathic kidney stone composition. Fourier transform infrared spectroscopy (FT-IR) allows to detect the ratio of calcium oxalate dihydrate (COD) and monohydrate (COM) crystals in stones, but the clinical significance of this parameter remains uncertain. The objective of this observational study was to verify the association of clinical and laboratory parameters of kidney stone disease with COD/COM ratio in a group of 465 (322 M, age 46 ± 14) patients suffering from idiopathic calcium nephrolithiasis with pure calcium oxalate stones (≥ 97%). Each participant underwent a complete clinical examination, serum chemistry, 24-h urine collection for the determination of the profile of lithogenic risk, and had stones analyzed by FT-IR. Most (62%) of the stones had a COD/COM ratio ≤ 0.25, and the urine chemistry of the corresponding patients showed a low prevalence of urinary metabolic abnormalities. With increasing COD/COM ratio intervals (0–0.25, 0.26–0.50, 0.51–0.75, 0.76–1), a significant association was observed for the number of urological procedures, serum calcium, 24-h urinary calcium excretion, prevalence of hypercalciuria and relative calcium oxalate supersaturation, and a negative trend was detected for the age of the first stone episode (all p values < 0.05). A linear regression model showed that the only parameters significantly associated with COD/COM ratio were 24-h urinary calcium excretion (standardized β = 0.464, p < 0.001) and urine pH (standardized β = 0.103, p = 0.013). In pure calcium oxalate idiopathic stones, COD/COM ratio may reflect the presence of urinary metabolic risk factors, and represent a guide for the prescription of urinary analyses

    Insulin Sensitivity and Secretion in Arab Americans with Glucose Intolerance

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    Background: This study examined the pathophysiological abnormalities in Arab Americans with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT). Subjects and Methods: Homeostasis model assessment of insulin resistance (HOMA-IR), homeostasis model assessment of insulin secretion (HOMA-%?), and the Matsuda Insulin Sensitivity Index composite (ISIcomposite) were calculated from the fasting and stimulated glucose and insulin concentrations measured during the oral glucose tolerance test in a population-based, representative, cross-sectional sample of randomly selected Arab Americans. Results: In total, 497 individuals (42±14 years old; 40% males; body mass index [BMI], 29±6?kg/m2) were studied. Multivariate linear regression models were performed to compare HOMA-IR, HOMA-%?, and ISIcomposite among individuals with normal glucose tolerance (NGT) (n=191) versus isolated IFG (n=136), isolated IGT (n=22), combined IFG/IGT (n=43), and diabetes (n=105). Compared with individuals with NGT (2.9±1.6), HOMA-IR progressively increased in individuals with isolated IFG (4.8±2.7, P<0.001), combined IFG/IGT (6.0±4.3, P<0.001), and diabetes (9.7±8.3, P<0.001) but not in those with isolated IGT (3.0±1.7, P=0.87). After adjustment for sex and BMI, these associations remained unchanged. Whole-body insulin sensitivity as measured by ISIcomposite was significantly lower in individuals with isolated IFG (3.9±2.3, P<0.001), isolated IGT (2.8±1.5, P<0.001), combined IFG/IGT (1.9±1.1, P<0.001), and diabetes (1.6±1.1, P<0.001) compared with those with NGT (6.1±3.5). HOMA-%? was significantly lower in diabetes (113.7±124.9, P<0.001) compared with NGT (161.3±92.0). After adjustment for age, sex, and BMI, isolated IFG (146.6±80.2) was also significantly associated with a decline in HOMA-%? relative to NGT (P=0.005). Conclusions: This study suggests that differences in the underlying metabolic defects leading to diabetes in Arab Americans with IFG and/or IGT exist and may require different strategies for the prevention of diabetes.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140352/1/dia.2013.0045.pd
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