1,720,998 research outputs found
Indices of apoptosis and proliferation as potential prognostic markers in non-functioning pituitary adenomas
No full textOBJECTIVE: Non-functioning pituitary adenomas (NFAs) are a distinct group of pituitary adenomas, which comprise approximately 20% of pituitary adenomas. Although most pituitary adenomas are benign, there is a subset of adenomas that behaves in an aggressive fashion, with either invasion of the surrounding structures or recurrence. The aim of this study was to investigate whether the behaviour of NFAs can be predicted using immunohistochemical markers that label proliferating and apoptotic cells, including a new marker for apoptosis (M30 CytoDEATH). This is the first study to analyse both the proliferation labelling index (LI) and the apoptotic index (AI) in NFAs and to correlate the labelling indices of these histological markers with tumor growth rate as measured by 2 postoperative MRI scans. MATERIAL AND METHODS: 40 patients in total were included in the study. 20 patients with high growth rate and percentage change in the pituitary adenoma volume as assessed on 2 postoperative MRI scans were age/sex matched to 20 patients with low growth rate or percentage change.RESULTS: There is no significant statistical difference of the histological and immunohistochemical indices assessed between cases and controls.CONCLUSION: The routine assessment of the proliferation and the apoptotic markers used in this study in NFAs has no prognostic value
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
Analysis of ependymomas using comparative genomic hybridisation
No full textBackground and objectives Ependymomas are the third most common CNS tumours in childhood, and account for 9–12% of CNS neoplasms in all age groups. However, the prognosis for cases not completely excised is poor and the underlying biology of their development and progression is poorly understood. The few studies published to date have suggested that specific chromosomal abnormalities may be associated with the development of a significant proportion of these tumours. We setout to screen a large series of intracranial and spinal ependymomas for genetic imbalances, and to correlate these with histology and clinical behaviour.Methods Comparative genomic hybridisation (CGH) was used to detect chromosome imbalances on 86 ependymomas from 77 patients, of which 22 were children under 16, treated at one of three UK centres (Newcastle, Nottingham, Southampton). Cases were first analysed without reference to histology or clinical features, and were then divided up according to anatomical location, histology and age at presentation.Results Chromosomal imbalances were detected in tumours from 63/77 patients (82%). The majority involved entire chromosomes or chromosome arms, many showing patterns of gains suggestive of intermediate ploidy. Of previously reported abnormalities in ependymoma, the most frequent findings were gain of 1 q, seen in 13 cases (17%), and loss of 22 in 20 (26%). Whereas 1 q gain was seen mainly in posterior fossa tumours and was restricted to those with classic and anaplastic histology, loss of 22 was rarely observed in tumours from this location and their histology was predominantly classic or myxopapillary. In contrast to previous studies, loss of 6q was found in only 6 cases (8%) and in only one child. Out of 7 tumours biopsied at presentation and relapse, 4 revealed imbalances and 3 of these demonstrated progression of abnormalities at relapse.Conclusions Chromosomal imbalance is common in ependymoma and patterns of abnormality are emerging that are associated with histology or location. Further studies are needed to establish the prognostic significance of these abnormalities
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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