934 resultados para SMITH, A. Mark. (2008a). “Alhacen´s Approach to “Alhazen´s Problem””. Arabic Sciences and Philosophy, vol. 18 pp. 143-163.


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This work deals with the theory of Relativity and its diffusion in Italy in the first decades of the XX century. Not many scientists belonging to Italian universities were active in understanding Relativity, but two of them, Max Abraham and Tullio Levi-Civita left a deep mark. Max Abraham engaged a substantial debate against Einstein between 1912 and 1914 about electromagnetic and gravitation aspects of the theories. Levi-Civita played a fundamental role in giving Einstein the correct mathematical instruments for the General Relativity formulation since 1915. This work, which doesn't have the aim of a mere historical chronicle of the events, wants to highlight two particular perspectives: on one hand, the importance of Abraham-Einstein debate in order to clarify the basis of Special Relativity, to observe the rigorous logical structure resulting from a fragmentary reasoning sequence and to understand Einstein's thinking; on the other hand, the originality of Levi-Civita's approach, quite different from the Einstein's one, characterized by the introduction of a method typical of General Relativity even to Special Relativity and the attempt to hide the two Einstein Special Relativity postulates.

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We evaluated the feasibility of a modified embolization technique of pulmonary arteriovenous malformations (PAVM) using venous sac embolization with detachable coils combined with the feeding artery embolization with the Amplatzer vascular plug (AVP).

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Profiling miRNA expression in cells that directly contribute to human disease pathogenesis is likely to aid the discovery of novel drug targets and biomarkers. However, tissue heterogeneity and the limited amount of human diseased tissue available for research purposes present fundamental difficulties that often constrain the scope and potential of such studies. We established a flow cytometry-based method for isolating pure populations of pathogenic T cells from bronchial biopsy samples of asthma patients, and optimized a high-throughput nano-scale qRT-PCR method capable of accurately measuring 96 miRNAs in as little as 100 cells. Comparison of circulating and airway T cells from healthy and asthmatic subjects revealed asthma-associated and tissue-specific miRNA expression patterns. These results establish the feasibility and utility of investigating miRNA expression in small populations of cells involved in asthma pathogenesis, and set a precedent for application of our nano-scale approach in other human diseases. The microarray data from this study (Figure 7) has been submitted to the NCBI Gene Expression Omnibus (GEO; http://ncbi.nlm.nih.gov/geo) under accession no. GSE31030.

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The areca alkaloids comprise arecoline, arecaidine, guvacoline, and guvacine. Approximately 600 million users of areca nut products, for example, betel quid chewers, are exposed to these alkaloids, principally arecoline and arecaidine. Metabolism of arecoline (20 mg/kg p.o. and i.p.) and arecaidine (20 mg/kg p.o. and i.p.) was investigated in the mouse using a metabolomic approach employing ultra-performance liquid chromatography-time-of-flight mass spectrometric analysis of urines. Eleven metabolites of arecoline were identified, including arecaidine, arecoline N-oxide, arecaidine N-oxide, N-methylnipecotic acid, N-methylnipecotylglycine, arecaidinylglycine, arecaidinylglycerol, arecaidine mercapturic acid, arecoline mercapturic acid, and arecoline N-oxide mercapturic acid, together with nine unidentified metabolites. Arecaidine shared six of these metabolites with arecoline. Unchanged arecoline comprised 0.3-0.4%, arecaidine 7.1-13.1%, arecoline N-oxide 7.4-19.0%, and N-methylnipecotic acid 13.5-30.3% of the dose excreted in 0-12 h urine after arecoline administration. Unchanged arecaidine comprised 15.1-23.0%, and N-methylnipecotic acid 14.8%-37.7% of the dose excreted in 0-12 h urine after arecaidine administration. The major metabolite of both arecoline and arecaidine, N-methylnipecotic acid, is a novel metabolite arising from carbon-carbon double-bond reduction. Another unusual metabolite found was the monoacylglyceride of arecaidine. What role, if any, that is played by these uncommon metabolites in the toxicology of arecoline and arecaidine is not known. However, the enhanced understanding of the metabolic transformation of arecoline and arecaidine should contribute to further research into the clinical toxicology of the areca alkaloids.

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OBJECTIVES We sought to evaluate the strategy success and short term clinical outcomes of direct stenting via 5 French (F) diagnostic catheters using a novel bare metal stent with integrated delivery system (IDS) (Svelte Medical Systems, New Providence, NJ) and compare the results to a conventionally treated matched group. METHODS Fifteen consecutive patients with lesions deemed suitable for direct stenting using a bare metal stent were included. The primary endpoint was the strategy success defined as the ability to successfully treat a target lesion via a 5 F diagnostic catheter with a good angiographic result (TIMI III flow, residual stenosis ≤20%). Procedure and fluoroscopy times, contrast agent use, cost, and short-term clinical outcomes were compared to a matched group treated via conventional stenting. RESULTS The primary endpoint was reached in 14/15 patients (93%). There were no significant differences in procedural (58.6 min ± 12.7 vs. 57.4 min ± 14.2) or fluoroscopy times (10.0 min ± 4.3 vs.10.1 min ± 3.9) or contrast agent use (193.7 ml ± 54.8 vs. 181.4 ml ± 35.6). However, there were significant reductions in materials used in the study group compared to the control group equating to cost savings of almost US $600 per case (US $212.44 ± 258.09 vs. US $804.69 ± 468.11; P = 0.001). CONCLUSIONS Direct stenting using a novel bare metal stent with an IDS via 5 F diagnostic catheters is a viable alternative to conventional stenting in selected patients and is associated with significant cost savings.

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Farmed and wild salmonids are affected by a variety of skin conditions, some of which have significant economic and welfare implications. In many cases, the causes are not well understood, and one example is cold water strawberry disease of rainbow trout, also called red mark syndrome, which has been recorded in the UK since 2003. To date, there are no internationally agreed methods for describing these conditions, which has caused confusion for farmers and health professionals, who are often unclear as to whether they are dealing with a new or a previously described condition. This has resulted, inevitably, in delays to both accurate diagnosis and effective treatment regimes. Here, we provide a standardized methodology for the description of skin conditions of rainbow trout of uncertain aetiology. We demonstrate how the approach can be used to develop case definitions, using coldwater strawberry disease as an example.

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Purpose: To discuss the approach and recommendations related to the adoption of school based curriculum for violence prevention. Findings: Preliminary assessments suggest that middle and high school youth experience a variety of forms of violence in social and dating relationships. Such experiences have negative academic, behavioral and emotional consequences. Conclusions: The authors have clearly illuminated the need for addressing the phenomenon of dating violence. The field could benefit from more robust evidenced-based investigations that substantiate that interventions have an impact beyond attitudinal changes toward the behavior. Such academic endeavors will provide a platform to validate the inclusion of such information in a school based curriculum as act as a call for action for broad based interventions.

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The inventors in PATSTAT are often duplicates: the same person or company may be split into multiple entries in PATSTAT, each associated to different patents. In this paper, we address this problem with an algorithm that efficiently de-duplicates the data. It needs minimal manual input and works well even on consumer-grade computers. Comparisons between entries are not limited to their names, and thus this algorithm is an improvement over earlier ones that required extensive manual work or overly cautious clean-up of the names.

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Within children's geographies there has been an absence concerning sexuality and in particular how this can lead to the discimination and marginalisation of individuals. Similarly, within geographies of sexualities the demographic of non-heterosexual children and youth has been under researched, with studies concerning the space of the school being very limited. This thesis sought to address these absences by carrying out qualitative interviews with non-heterosexual individuals about their school experiences. The interviews showed the importance and variation of both physical and time-spaces in the (re)production of heteronormativities, and that the agency of the indiviudal was asserted through the use of negotiation strategies that sought to navigate or resist heteronormativities.

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The reliability of measurement refers to unsystematic error in observed responses. Investigations of the prevalence of random error in stated estimates of willingness to pay (WTP) are important to an understanding of why tests of validity in CV can fail. However, published reliability studies have tended to adopt empirical methods that have practical and conceptual limitations when applied to WTP responses. This contention is supported in a review of contingent valuation reliability studies that demonstrate important limitations of existing approaches to WTP reliability. It is argued that empirical assessments of the reliability of contingent values may be better dealt with by using multiple indicators to measure the latent WTP distribution. This latent variable approach is demonstrated with data obtained from a WTP study for stormwater pollution abatement. Attitude variables were employed as a way of assessing the reliability of open-ended WTP (with benchmarked payment cards) for stormwater pollution abatement. The results indicated that participants' decisions to pay were reliably measured, but not the magnitude of the WTP bids. This finding highlights the need to better discern what is actually being measured in VVTP studies, (C) 2003 Elsevier B.V. All rights reserved.