1,721,073 research outputs found
Clinical and molecular diagnosis of cerebrotendinous xanthomatosis with a review of the mutations in the CYP27A1 gene
No full textCerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disease due to defective activity of the mitochondrial enzyme sterol 27-hydroxylase. In 1991, sterol 27-hydroxylase gene (CYP27A1) was localised on the long arm of chromosome 2 [1]. Clinical characteristics of CTX are diarrhoea, cataracts, tendon xanthomas and neurological manifestations including dementia, psychiatric disturbances, pyramidal and/or cerebellar signs, and seizures. More than 300 patients with CTX have been reported to date worldwide and about 50 different mutations identified in the CYP27A1 gene. Almost all mutations lead to the absence or inactive form of the sterol 27-hydroxylase. In this review, according with the aims of this section of the journal, we describe the different pathogenetic mutations in the CYP27A1 gene and the main clinical and pathogenetic aspects that may help clinical neurologists in the diagnosis of CTX
Raffronto di Vari Metodi per l’Identificazione dell’Espressione Genica Differenziale, un’Applicazione con Oligonucleotidi alla Soppressione del Gene Antiapoptosi Survivina
No full textA very common problem that is adressed using microarray technology is that of identificating genes that are differentially expressed between two or more classes of samples. For this purpose many methods have been proposed and made available to a wide range of users by supplying related software. Refinements of familiar tools such as the t-test are used to take the multiplicity problem into account (Dudoit et al. 2002), and to obtain a reliable estimate of the variance of gene expression (Tusher et al. 2001), as well as model based methods, both in a frequentist (Kerr and Churchill 2001) and Bayesian framework (Gottardo et al. 2002). These methods imply different hypotheses and their use on data can lead to substantially different results. The purpose of this work is to evaluate and compare, through a case study, results from different methods for identifying differentially expressed genes
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Il monitoraggio biologico dei lavoratori esposti a tossici industriali. aggiornamenti e sviluppi
No full textFactors related to glycemic control in IDDM and insulin-treated NIDDM patients in current practice. A comparison of care policies. SIEMTIC Group. Studio Italiano Epidemiologico Multicentrico su Terapia Insulin e Controllo Metabolico.
No full textImproving Step Performance of PMU Algorithms: Left and Right Taylor-Fourier Expansions
No full textModern power systems are characterized by fast dynamics, due to the massive presence of power electronic converters. In this scenario, the present paper proposes an approach for measuring synchrophasor, frequency and rate of change of frequency (ROCOF) that allows to effectively cope with abrupt transients. The method is based on Taylor-Fourier models, which typically consider a symmetric observation window with respect to the reporting instant. In this paper, the Taylor expansion is also performed on asymmetric windows, that look either at the left or at the right of the measurement instant. A robust rule enables detecting the presence of an abrupt transient, so that the best expansion is selected. Results show an exemplary behavior in amplitude and phase step tests, also in the presence of wideband noise
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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