1,721,230 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“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
Get PDFWe 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
Utilité des tests fonctionnels dans les neuropathies amyloïdes familiales
No full textI.4 But du travail
Un travail de thèse mené par une doctorante en physiopathologie (Irène Calero-Romero, sous la direction du Prof. F. Feihl, CHUV) a permis de recenser une quinzaine de patients souffrant de NAF (neuropathie amyloïde familiale) et d'évaluer l'utilité de mesures de quantification par « laser-doppler flowmetry». Cette étude a investigué une technique basée sur le réflexe d'axone vasomoteur cutané, en estimant le flux sanguin cutané avant et après l'application locale d'un stimulus électrique ou chimique (histamine), par les propriétés doppler d'un balayage laser de la peau. La fonction des PF périphériques a pu être ainsi objectivée en mesurant l'importance de l'érythème induit.
Dans ce contexte d'atteinte sélective dans les NPF et de l'évaluation des PF par laser Doppler, ont été aussi étudiées les corrélations entre données cliniques et le testing sensitif cutané (QST). Les objectifs de ce travail de Maîtrise ont donc été de rassembler les dossiers des patients NAF en étudiant les données épidémiologiques, cliniques, biologiques et les examens complémentaires, et de les corréler aux déficits quantifiés par le QST
Expanding view of phenotype and oxidative stress in Friedreich's ataxia patients with and without idebenone
No full textSummary:
Friedreich's ataxia (FRDA), the most common autosomal recessive ataxia, is characterised by progressive ataxia with dysarthria of speech, loss of deep-tendon reflexes, impaired vibratory and proprioceptive sensations and corticospinal weakness with a Babinski's sign. Patients eventually also develop kyphoscoliosis, cardiomyopathy and diabetes mellitus. The disease is a GAA repeat disorder resulting in severely reduced levels of frataxin, with secondary increased sensitivity to oxidative stress. The anti-oxidative drug, idebenone, is effective against FRDA-associated cardiomyopathy. We provide detailed clinical, electrophysiological and biochemical data from 20 genetically confirmed FRDA patients and have analysed the relation-ship between phenotype, genotype and malondialdehyde (MDA), which is a marker of superoxide formation. We assessed the effects of idebenone biochemically by measuring blood M DA and clinically by serial measurements of the International Cooperative Ataxia Rating Scale (ICARS). The GAA repeat length influenced the age at onset (p <0.001), the severity of ataxia (p= 0.02), the presence of cardiomyopathy (p =0.04) and of low-frequency hearing loss (p = 0.009). Multilinear regression analysis showed (p = 0.006) that ICARS was dependent on the two variables of disease duration (p = 0.01) and size of the GAA expansion (p = 0.02). We found no correlation to bilateral palpebral ptosis visual impairment, diabetes mellitus or skeletal deformities, all of which appear to be signs of disease progression rather than severity. We discuss more thoroughly two underrecognised clinical findings: palpebral ptosis and GAA length-dependent low-frequency hearing loss. The average ICARS remained unchanged in 10 patients for whom follow-up on treatment was available (mean 2.9 years), whereas most patients treated with idebenone reported an improvement in dysarthria (63%), hand dexterity (.58%) and fatigue (47%) after taking the drug for several weeks or months. Oxidative stress analysis showed an unexpected increase in blood MDA levels in patients on idebenone (p = 0.04), and we discuss the putative underlying mechanism for this result, which could then explain the unique efficacy of idebenone in treating the FRDA-associated cardiomyopathy, as opposed to other antioxidative drugs. Indeed, idebenone is not only a powerful stimulator of complexes II and III of the respiratory chain, but also an inhibitor of complex I activity, then promoting superoxide formation. Our preliminary clinical observations are the first to date supporting an effect of idebenone in delaying neurological worsening. Our MDA results point to the dual effect of idebenone on oxidative stress and to the need for controlled studies to assess its potential toxicity at high doses on the one hand, and to revisit the exact mechanisms underlying the .physiopathology of Friedreich's ataxia on the other hand, while recent reports suggest non-oxidative pathophysiology of the disease
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
IRM musculaire corps entier selon Dixon en pathologie neuromusculaire
No full textIntroduction L'utilisation de séquences corps entier de l'IRM en séquences musculaires (mWB MRI) à contrastes rend compte en un seul temps de la charge en eau ou en graisse du muscle, correspondant à une inflammation ou infiltration graisseuse, en plus de la réduction de volume du muscle ou amyo- trophie. La technique Dixon est basée sur ces principes, en utilisant quatre reconstructions tirées d'une seule « double » acquisition IRM (en phase, IP, et en opposition de phase, OP), dont deux images re- construites du signal de l'eau seule (ou water) et de la graisse seule (ou fat).
Notre étude a pour but de répondre aux questions suivantes: - quel est l'impact du mWB MRI Dixon dans la prise en charge des patients au CHUV depuis son introduction en 2013 ? - Quels sont les élé- ments cliniques, para-cliniques et radiologiques associés à un changement de prise en charge chez ces patients ?
Matériel et méthodes Tous les examens mWB MRI ont été revus. Les données cliniques et d'imagerie ont été regroupées avec une cotation binaire. Une échelle de cotation radiologique binaire a été mise au point pour caractériser l'atteinte musculaire et les séries d'images ont été relues selon cette grille avec un radiologue musculosquelettique. Les examens ont été classés en catégories selon l'indication à l'imagerie et selon le diagnostic. La base de données ainsi établie a été complétée par le résultat des examens paracliniques (CK, ENMG, biopsie musculaire et son site). Deux groupes « mWB MRI contribu- tif » et « mWB MRI non contributif » à la prise en charge ont été constitués et leurs caractéristiques comparées entre elles par une régression logistique uni et multivariée.
Résultats Globalement, le mWB MRI s’est révélé contributif dans 54,2% des cas (45/83) pour le dia- gnostic et la prise en charge. Dans 37,3% des cas (31/83), l’examen a permis un changement de prise en charge, que ce soit dans la décision de commencer une prise en charge (N=8) ou d'en éviter une (N=23). Dans 16,8% des cas (14/83), l'examen n'a pas modifié le traitement initialement prévu, mais il a permis de documenter l'étendue de la maladie ou l'atteinte de groupes musculaires asymptoma- tiques.
Statistiquement, le mWB MRI a été contributif lorsqu'il évoquait une maladie neuromusculaire (p<0,001). La présence d'infiltration graisseuse (p<0,01) et d'œdème (p=0,01) rend également les examens contributifs pour le traitement. Un dosage des CK pathologique est fréquemment retrouvé dans le groupe contributif (p=0,11). Un ENMG pratiqué avant l'imagerie augmente la probabilité que le mWB MRI soit non contributif (p=0,09). Une biopsie réalisée avant le mWB MRI (p=0,37) ou un résultat pathologique de la biopsie (p=0,16) sont fréquemment retrouvés parmi les mWB MRI contributifs, ces résultats sont toutefois sans signification statistique.
Conclusion Le mWB MRI occupe une place centrale dans le diagnostic et la prise en charge des pa- tients atteints de maladies neuromusculaires. Il est utilisé comme examen de débrouillage et de sélec- tion d'un muscle candidat à une biopsie, ou comme complément à une biopsie négative en présence d'une clinique évocatrice. L'IRM peut dans certains cas se placer en amont de la clinique et détecter des anomalies de signal chez des sujets asymptomatiques
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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