1,720,957 research outputs found
Non-motor aspects of parkinson's disease
No full textFor many decades, PD was regarded as a unique entity, namely a sporadic neurodegenerative disease with its main lesion in the substantia nigra. The actual pathology was described as pathognomonic Lewy bodies in nigral dopaminergic cells, and the clinical abnormalities were thought to be due to insufficient dopamine release from nigrostriatal terminals, primarily in the putamen. It is now realized that the classical stereotypic description of PD starting with tremor or hypokinesia/rigidity and progressing to postural instability and eventually to cognitive decline is not the only scenario (although it may be the more common one). This latter observation led to a definition of the "Lewy body dementia" concept where motor symptoms may be minimal initially. In many patients, the disease starts with autonomic (particularly gastro-intestinal) or sensory (i.e., olfactory) manifestations. The identification of a-synuclein as a key constituent of Lewy bodies allowed the demonstration of specific changes in other areas such as the olfactory bulb and particularly the brain stem. Changes in the raphe nucleus and the locus coeruleus which antedate the substantia nigra lesions could explain some mental manifestations, particularly the depression which has been described prior to the first motor manifestations. Several behavioral disorders may be observed in people with PD. Hypodopaminergic states linked to the disease itself or associated with low levodopa levels may frequently contribute to symptoms such as anxiety, apathy, fatigue, sleep disruption. About twothirds of PD patients with fluctuations reported significant "on-off" mood swings. The excessive use of dopaminergic treatment may eventually lead to a pervasive behavioral syndrome termed homeostatic hedonistic dysregulation (HHD). We discuss these aspects with a particular interest in clinical practice
Parkinson's disease as a model of basal ganglia disruption
No full textThe assumption that the PD neurodegenerative process begins in the dopaminergic substantia nigra has been seriously challenged by recent publications. New different studies have provided evidence in support of a lower brainstem origin, predating involvement of the nigra. In addition to the prominent loss of nigro-striatal dopamine neurons, there is also degeneration of nor-epinephrine neurons in the locus coeruleus, cholinergic neurons in the nucleus basalis of Meynert, the dorsal motor nucleus of the vagus, and involvement of the spinal cord and peripheral autonomic system. There is dysfunction of multiple neurotransmitter systems and research is underway to determine if therapeutic restoration of these transmitters can provide benefit in PD. We discuss these biochemical and pathological aspects inside the most classic clinical assumption of PD as a dopaminergic depletion-induced diseas
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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