1,721,012 research outputs found
Lhermitte-Duclos disease: MR diffusion and spectroscopy
No full textAIM:
To describe two cases of Lhermitte-Duclos disease studied with Diffusion MRI and MRi Spectroscopy.
MATERIALS AND METHODS:
Two patients showing a space-occupying lesion in the cerebellar hemisphere were studied by conventional MRI associated with Diffusion MRI and Spectroscopy.
RESULTS:
Conventional MRI showed the typical morphological pattern of Lhermitte-Duclos disease with a slow-growing cerebellar mass mainly involving the cortex and non-enhancing thickened cerebellar folia. The mass exerted mild compression of the IV ventricle causing hydrocephalus On Diffusion imaging showed the lesion to be hyperintense due to residual T2-activity and hypointense on the ADC map. Spectroscopy was typical with an increased lactate peak and a reduced choline peak, indicating abnormal anaerobic glycolysis and demyelination, respectively.
DISCUSSION:
Lhermitte-Duclos disease is a neurological condition which presents several signs and symptoms related to the cerebellar mass. Cowden's syndrome, an autosomal dominant neoplastic disorder with malignant features is associated in 40% of cases. MRI associated with functional examinations such as Diffusion Imaging and Spectroscopy is the imaging modality of choice in LDD patients. They allow a definite diagnosis as the neuroradiological findings correlate well with molecular biology theories regarding the malformative nature of dysplastic cerebellar gangliocytoma
Migrainous infarction: Association with vascular risk factors in a male subject
No full textMigraine with aura (MA) is associated with an increased risk of ischemic stroke, especially in young women with vascular risk factors (smoke, contraceptive pill). Patent foramen ovale (PFO) has also been associated with MA. We describe a 41-year-old man, in good health, with MA since 16, familiar history of diabetes, heavy smoker (30 cigarettes/day). Frequency (1-2 attacks/year) and clinical features of migraine have been unchanged since the onset. A few days before our examination he suffered a typical migraine attack. In the following hours, however, the headache became more and more throbbing and the aura symptoms (regressed as usual in 30 min) reappeared and persisted, so he went to an Emergency Department. The CT-scan (without contrast) was normal. The following days he had visual disturbances and spatial disorientation. We found a normal neurological examination and fundus oculi. He referred persisting visual troubles. We prescribed MR + angioMR which confirmed a migrainous infarction and ruled out others pathological conditions. Further tests found out dislipidemia, hyperhomocysteinemia, impaired glucose tolerance. Transcranial Doppler showed right to left shunting. We also prescribed the screening tests for vasculitis (normal). In our opinion this case highlights the relevance of vascular risk factors in MA complications also in male subjects. © Springer-Verlag 2009
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
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
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
Quartz Crystal Microbalance as Cell-Based Biosensor to Detect and Study Cytoskeletal Alterations and Dynamics
No full text- …
