1,720,958 research outputs found
Motor and somatosensory evoked potentials in autosomal dominant hereditary spastic paraparesis (ADHSP) linked to chromosome 2p, SPG4
No full textAbstract
The aim of our study was to evaluate Motor Evoked Potentials (MEPs) and cortical excitability, using Transcranial Magnetic Stimulation (TMS) as well as short latency Somatosensory Evoked Potentials (SEPs) in Autosomal Dominant Hereditary Spastic Paraparesis (ADHSP) patients. MEPs were recorded from upper and lower limb muscles in 12 patients (7 m and 5f) affected by ADHSP with spastin mutation (SPG4). We measured: (i) motor threshold (MTh); (ii) total motor conduction time (TMCT); (iii) direct and indirect central motor conduction time (d-CMCT and i-CMCT) calculated by subtracting from the cortical latency those obtained on magnetic spinal stimulation (d-PMCT) and via the F-wave method (i-PMCT); (iv) MEP amplitude (MEP/Mmax ratio%) and (v) duration of the cortical silent period (CSP). Latency, amplitude and persistence of the F-wave obtained with electrical nerve stimulation were also considered; H reflex was also tested from lower extremities. SEPs were recorded from spine and scalp sites following median and posterior tibial nerve stimulation; conventional latency and amplitude measurements were performed. In a comparison with the control group, the MTh recording from lower limbs was significantly higher (67.5 +/- 7.7% versus 52.5 +/- 6.9%), MEPs were absent in one case and showed reduced amplitude in the remainders (22.9 +/- 12.6% versus 66.3 +/- 25.9% of M wave); TMCT resulted to be abnormal (36.5 +/- 3.9 ms versus 27.1 +/- 1.4 ms) and d-CMCT as well as i-CMCT were significantly prolonged (23.1 +/- 3.5 ms versus 13.8 +/- 1.3 ms; and 20.1 +/- 3.4 ms versus 10.6 +/- 1.3 ms, respectively). The CSP, which was normal from the hands, was significantly shortened from the legs and correlated with spasticity scoring (Ashworth scale). Cortical SEPs from lower limbs were abnormal in all cases, whereas SEPs by stimulation of median nerves were normal; F-wave parameters from upper limbs showed no abnormalities, whereas an increased persistence was detected from lower limbs; H reflex amplitudes resulted larger compared with controls. Moreover, shortening of the CSP, being correlated with the Ashworth scale, can be considered an electrophysiological marker of spasticity that seems to arise from impairment of the supraspinal or intracortical inhibitory pathways with an additional contribution of increased segmental motor neuron excitability. These data prove the existence of comparable neurophysiological abnormalities in ADHSP with spastin mutation (SPG4) when long ascending and descending pathways are involved
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
Metabolic muscle adaptation to aerobic training in patients affected by mitochondrial myopathies.
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