1,720,996 research outputs found
Balance in elderly: overview and personal experience in Paroxysmal Positional Vertigo (PPV)
No full textAge-related hearing loss: biological aspects
No full textPresbycusis is one of the more prevalent neurodegenerative disease of aging. There are many studies about the influence of environmental and genetic factors. Age-related hearing loss is caused by changes in peripheral (cell loss in organ of Corti, spiral ganglion and stria vascularis) and central auditory systems (consequent to peripheral modifications or for changes in the neurobiologic activity underlying central processing of auditory informations) [1]. Consequences are reduced sensitivity, tuning sharpness, compression, and reduced signal-to-noise ratios, deficits in auditory discrimination, temporal processing, processing of degraded auditory signals or when embedded in competing acoustic signals. Approaching biology of age-related hearing loss is complex: it needs to clarify some peripheral aspects with different cochlear structure and cellular type affected, and some others central auditory processing aspects. There are some peripherally induced central effects and others direct neurodegenerative changes in the brain. Moreover biochemical and mechanical injury in life course can represent a risk factor for auditory function particularly for organ of Corti. This complicates the attempt of separate pure presbycusis from socioacusis. Research indicated some "longevity genes" and longevity-promoting life-styles (obesity and correlated conditions like hyperlipidemia, hypercholesterolemia, hypertension, hyperhomocysteinemia and cardiovascular disease, smoking, diet and diabetes [2,3]. Age-related hearing loss seems to occur more frequently in industrial population than in non-industrial [4]. The relation between alleles pro or against-aging and environment maybe play a determinant role in the evolution of hearing with aging. Until such genes are identified, the best strategy is to reduce environmental risk factors (noise exposure, ototoxic drugs, industrial solvents or combinations of these)
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
Database of benign positional paroxysmal nystagmus.
No full textClassification of various manifestations of benign positional paroxysmal nystagmus, due to canalolithiasis or to cupulolithiasis, as a reaction to movements and to the site of detritus, is now possible due to the integration of theoretical knowledge (relationships between the semicircular canals and/or ampullae and the vestibulo-ocular pathways) with the forms of nystagmus induced when the head is placed in various positions. A comparison is made of results in patients examined in three Departments, during the past 3 years, and data presented in the literature. Findings are presented in a database which enables the clinician to compare the standard diagnostic manoeuvres (Dix-Hallpike, Pagnini-McClure, Rose) with results obtained by placing the head in alternative positions. This approach offers all the information needed to identify the site of onset and hence to formulate a correct diagnosis, thus directly indicating the most appropriate liberating or repositioning manoeuvre or--in the case of a suspected central lesion--to suggest further tests. Moreover, it is suggested that this table could become a useful tool for teaching purposes
Surgical treatment of recurring preauricular sinus: supra-auricular approach.
No full textCongenital preauricular sinus is a malformation of the preauricular soft tissues with an incidence ranging between 0.1 and 0.9\% in Europe and the United States. It presents a high risk of recurrence when treated by a standard surgical technique (simple sinectomy), the incidence of which is reported to be between 19\% and 40\%. The supra-auricular approach, proposed by Prasad et al. in 1990, is easier to perform and presents a lower recurrence risk. Personal experience is presented in the treatment of congenital preauricular sinus with the supra-auricular approach as first choice or in the case of recurrence following previous standard surgery. This report includes a short review of the literature in order not only to focus on the supra-auricular approach and check the efficacy as far as concerns reduction of recurrence risk but also to contribute to a more widespread use of this method
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