1,720,964 research outputs found
Le minorazioni visive
No full textGli autori definiscono l’ipovisione: danno visivo non corregibile per mezzo dei comuni occhiali da vista o lenti a contatto e come una situazione patologica che interferisce con la capacità di adempiere alle normalità attività quotidiane.
I soggetti ipovedenti possono comunque trovare beneficio nell’uso di particolari strumenti ottici e non ottici e per mezzo di specifiche tecniche riabilitative. Quindi viene evidenziata l’importanza di un accurato esame della funzione visiva basato principalmente sulla valutazioni di: contrasto limite, risoluzione e campo visivo. In base a tali accertamenti sarà possibile classificare i soggetti ipovedenti facendo riferimento al testo di legge (riportato) n. 138 del 3 Aprile 2001: Classificazione e quantificazione delle minorazioni visive e norme in materia di accertamenti oculistici
Una nuova tecnica per la misurazione dell’autofluorescenza del fondo oculare: modulo software per l’analisi quantitativa dell’autofluorescenza del fondo oculare
No full textA new method of autofluorescence quantification: software module autofluorescence quantitative analysis. Age related macular disease (AMD) is now the leading cause of severe visual loss in all industrialized countries. It may be speculated that changes seen in FAF imaging on the RPE cell level precede the occurrence of visible lesions as the disease progresses. There is no an universally accepted standard method to quantification FAF. It should be remembered that AF measurements are relative and subject to degradation by the lens, rather than absolute values obtained spectroscopically. To make quantitative assessment of abnormal AF we planed a new method based on the quantification of grey variations between two images of AF, recorded in different period, in the same patients. Key words: autofluorescence quantification, age-related macular degeneratio
Changes in fundus autofluorescence in patients with choroideal neovascularization pre and post photodynamic therapy. Correlation to visual function
No full textPURPOSE: To investigate fundus autofluorescence changes in patients with choroidal neovascularization (classic, minimally classic and occult CNV) pre and post photodynamic therapy (PDT) to correlate these changes to visual function. METHODS: Autofluorescence images were recorded in 30 consecutive eyes (30 patients) with CNV. All patients underwent a detailed ophthalmoscopic examination: best corrected visual acuity (BCVA) with Early Treatment Diabetic Retinopathy (ETDRS) charts; slit lamp examination; binocular funduscopy; OCT, AF, fluorescein and indocyanine angiography pre and post PDT (every two months from each PDT, follow-up 24 months). RESULTS: All eyes showed variations from the initial pattern. In the 43,3% of eyes we observed a marked reduction of macular AF with a minimal residual visual function and severe visual loss from the initial. In the 56,7% of eyes was evident only a minimal reduction of macular AF in correlation to a good residual visual function. CONCLUSION: Preserved AF post PDT indicates viable retinal pigment epithelium initially, which has implications for visual prognosis. Marked decrease of AF post PDT indicates loss of retinal pigment epithelium and photoreceptor with a severe visual loss. Minimal reduction of macular AF post PDT is in correlation to a good residual visual function. Autofluorescence imaging may increase our understanding of CNV in AMD after PDT. Variations in AF permit us to understand the behavior of CNV and the changes of final visual function. KEY WORDS: Choroidal neovascularization (CNV), autofluorescence (AF), retinal pigment epithelium (RPE), photodynamic therapy, visual function
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
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