1,720,987 research outputs found
Intralaboratory reproducibility of interpretation of pap smears: results of an experiment
No full textOne hundred and twenty Pap-smears were examined by 3 cytotechnologists on two occasions in the Legnano Hospital Cytologic Center. A 10-category classification system was used. Chance-adjusted overall and category-specific agreement was estimated (Cohen's unweighted kappa-statistics) within and between cytotechnologists. Mean K for the Center, weighted for precision, was 0.432, S.E. 0.029 (between cytotechnologists). The most reproducible categories (between cytotechnologists) were "9: malignant cells" (K = 0.683) and "1: normal" (K = 0.533); the least reproducible categories were "4: endocervical metaplastic cells" (K = 0.024) and "8: severe squamous dysplasia CIN III" (K = 0.227)
Polymer adsorption at the brine/rock interface : the role of electrostatic interactions and wettability
No full textInjection of polymers that selectively reduce the water permeability can be used to control water production from oil or gas wells. Because this method relies on the adsorption of a polymer layer onto the rock surface, a deeper understanding of the relevant polymer/rock interactions is of primary importance in order to develop reliable chemical selection rules for field applications. In this paper we study the role of electrostatic interactions and wettability in the adsorption of water-soluble polymers (bearing differently charged groups) onto solid surfaces of siliceous nature. By means of static adsorption tests, we show that the adsorption is dominated by the electrostatic interactions between the polymer molecules and the solid surface. We also show that lithology, brine composition and wettability are critical parameters that can influence the adsorption behavior at a brine/rock interface
Discovering asymptomatic non-precancerous lesions with cervical cytologic mass-screening campaigns: is it a benefit or a cost?
No full textA total of 3357 women (88.1% married, 82.0% parous) were examined at least once in the mass-screening program carried out by the Legnano Hospital Screening Center in Nerviano (a small town near Milan with 15,600 inhabitants) in 1974, 1977 and 1980. Married women with visible portio and adequate smear were 2758: a visibly healthy cervix was found only in 1143 subjects (41.4%). A total of 1516 married women were examined at least in 2 consecutive campaigns: 1279 (84.4%) reported "no gynecologic treatment in the previous 5 years" at the first campaign, and 899 (59.3%) reported "no gynecologic treatment in the previous 3 years" at their second one. Of 350 women with "medical lesions" and 525 with "surgical lesions" recorded at the first visit, 111 (31.7%) and 232 (44.2%) reported, respectively, a "medical treatment" or a "surgical treatment" at the second visit. In women with "medical lesions" at the first visit, at the second visit a healthy cervix was found in 66.2% of the treated women and in 72.6% of the untreated patients. In those with "surgical lesions" a healthy cervix was successively found in 91.6% of treated and in 40.7% of the untreated patients
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Candidate and chemical selection guidelines for relative permeability modification (RPM) treatments
No full textWater shutoff treatments with polymers that selectively reduce the water permeability can be effective at reducing water production from hydrocarbon wells that cannot be treated with conventional approaches. This paper describes the elaboration of understanding-based rules for candidate and chemical selection to guide the application of this technology in the field. These rules are based on an analysis of the principal operative issues and on experimental and simulation studies that explore the physical and chemical mechanisms governing treatment efficacy
Variations on the Author
Get PDF“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
Get PDFWe 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
Polymer/rock interactions in polymer treatments for water-cut control
No full textIn this paper we study the adsorption of polymers bearing differently charged groups onto solid surfaces of siliceous nature. By means of static adsorption tests we show that the adsorption is dominated by the electrostatic interactions between the polymer molecules and the solid surface. We also show that both lithology and brine composition can strongly influence the adsorption behavior; such effects must be therefore carefully assessed before applying these treatments in the field
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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