1,720,970 research outputs found
Retinal blood flow in senile macular degeneration. A Blue Field study [STUDIO DEL MICROCIRCOLO RETINICO CON LA TECNICA DEL BLUE FIELD IN PAZIENTI AFFETTI DA DEGENERAZIONE MACULARE SENILE]
No full textThe technique of the "Blue Field" simulation is based on an endo-optic phenomenon obtained by means of gazing a dark-blue and uniform light, of a 430 nanometers wave lenght. This phenomenon is due to the presence, in the retinal capillaries of 7-10 micrometers diameter, of red blood cells with some leucocytes among them, while the red blood cells do not allow the light to reach the retinal photoreceptors, the leucocytes are crossed by it, so being perceived as shining bodies.In order to obtain that, the patient is request to compare and balance the number of the perceived leucocytes,their velocity and rythm, by means of simulating with the help of a computer the presence of the leucocytes in a video display. This procedure is repeated five times.The Authors report the results obtained by using this technique in a group of 10 patients suffering from senile macular degeneration in prediskiform stage.In this way we pointed out that the circulation in the macular retinal capillaries in this patients is changed, in relation to the alterations of the visus from near
Valutazione critica degli esami fluoroangiografici eseguiti in due anni.
No full textGli AA valutano retrospettivamente gli esami fluoroangiografici effettuati in un periodo di 2 anni, sono valutate le indicazioni alla base della richiesta dell' approfondimento diagnostico fluoroangiografico in relazione alle complicanze delle varie patologie oculari; inoltre sono descritti possibili effetti secondari.The authors report a critical evaluation of two years of fluorescein angiograms, underling situations of limitation and over-utilization of angiographic service.
Key words: Fluorescein angiography, indications, ophthalmoscopy, macular diseases, diabetic retinopathy, retinal vascular diseases, choroidal tumors, optic disk diseases
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
Latent tuberculous infection among foreign-born individuals applying to shelters in the metropolitan area of Milan
No full textSETTING:
Screening for latent tuberculous infection (LTBI) of groups at high risk of active tuberculosis (TB) is a key component of the End TB Strategy.
OBJECTIVE:
To conduct a retrospective descriptive analysis of LTBI rates among foreign-born individuals applying to shelters in the metropolitan area of Milan, Italy.
DESIGN:
All foreign-born individuals registering for accommodation centres in the city of Milan from November 2009 to April 2017 were screened for active TB and LTBI. Individuals aged <36 years with a tuberculin skin test (TST) induration of >10 mm were offered confirmatory testing with QuantiFERON®-TB Gold In-Tube (QFT-GIT).
RESULTS:
Of the 2666 TST-positive migrants aged <36 years who underwent LTBI confirmation testing, 1322 (49.6%) tested negative, 1339 (50.2%) were positive and five (0.2%) had indeterminate results. In the multivariate analysis, TB incidence in the country of origin and age were significantly associated with QFT-GIT positivity. Although estimated TB incidence in Eritrea, Morocco and Romania was 100/100 000 person-years (py), the probability of being QFT-GIT-positive in individuals from these countries were not statistically significantly different from individuals from countries with TB incidence > 250/100 000 person-years.
CONCLUSION:
Our data showed a high proportion of LTBI among individuals coming from intermediate TB burden countries
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
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