1,720,967 research outputs found
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
Site- and time-specific emergence of adipogenic competence in skeletal stem cells determines the natural history of Fibrous Dysplasia of bone
No full textFibrous Dysplasia (OMIM174800) is a human genetic disease of the skeleton caused by point mutations in the GNAS gene, encoding the alpha subunit of Gs-alpha. The mutations arise from methylation-deamination sequence of cytosine in a CpG dinucleotide at codon 201 in pluripotent cells in early embryos, and can be modeled by heterotopic transplantation in SCID/bg mice of skeletal progenitors from the bone marrow of affected postnatal bones. We generated mouse model of the human disease expressing the disease gene either constitutively or as targeted to specific cell types in the bone/bone marrow environment. Mice with constitutively expressed GsaR201C develop an exact replica of the human disease over time, while mice with osteoblast-targeted mutation develop a different phenotype phenocopying high bone mass disorders caused by dyregulated Wnt signaling in humans. A detailed analysis of the mode of development of FD lesions, in mice, which consist in the deposition of abnormally unmineralized and over-remodeled bone that deforms and fractures, revealed that bone lesions arise from a unique process of unstable brownization of marrow adipocytes triggered by overproduction of cAMP and characterized by morphological and molecular changes (UCP-1, PGC1a) defining BAT. This process is followed by reprogramming of newly brownize marrow adipocytes to aberrant osteoblasts, which ectoptically express adipocyte genes. Among these, the gla-containing protein, Matrix Gla Protein (MGP; expressed in adipocytes but not in mouse osteoblasts) is a potent local inhibitor of bone mineralization, explaining the characteristic mineralization defect of FD bone both in humans and in mice. Importantly, the reprogramming of marrow adipocytes to aberrant osteoblasts via BAT occurs in an obligate site and time specific pattern, which is directly dictated by the emergence of adipogenesis at specific times and sites in the mouse bone marrow. Sites of yellow marrow such as the tail vertebrae are the first sites to be affected, and onset of disease coincides with onset of marrow adipogenesis. Of note, adipogenesis is a postnatal event in mouse bone marrow, and the entire bone formation process that spans prenatal development is accordingly normal in FD mice. Mouse ES cells expressing the mutation could be directed to be directed to normal chondrogenesis in vitro, and normal endochondral ossification in a transplantation model. These data demonstrate the significance of site and time specific emergence of differentiation potential in bone marrow skeletal progenitors; reveal that bone marrow adipocytes can be brownized by excess cAMP, as predictable from its effect in extramedullary beige and brown fat; demonstrate a unique path to bone disease strictly dependent on the existence and properties of skeletal stem cells and its dependent system of time an dsite specific lineage
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
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
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
Valutazione di nuovi marcatori molecolari di prognosi e risposta terapeutica nella leucemia linfatica cronica-B.
No full textLa leucemia linfatica cronica a cellule B (LLC-B) è la forma più comune di leucemia umana ed è caratterizzata dall’accumulo di piccoli linfociti B monoclonali CD5 positivi, non maturi nel sangue periferico, nel midollo osseo e negli organi linfatici. È una patologia eterogenea, ci sono dei pazienti che possono sopravvivere per diversi anni senza sintomi gravi e non necessitano di un trattamento farmacologico e altri che fin dall’esordio presentano una rapida progressione e richiedono un trattamento.
L’LLC-B si può manifestare in due forme aggressiva e indolente; la forma aggressiva è caratterizzata da una elevata espressione dello ZAP 70 e non presenta mutazioni delle IgVH, mentre la forma indolente è caratterizzata da una bassa espressione dello ZAP70 e presenta mutazioni delle IgVH.
Uno dei principali obiettivi della ricerca sull’LLC-B è quello di creare una stratificazione dei pazienti fin dal momento della diagnosi e nel corso del tempo sono stati definiti dei parametri classici (il tempo di raddoppiamento linfocitario, l’infiltrazione del midollo osseo) e più recentemente si è passati a utilizzare dei marcatori citogenetici, quali la presenza di alterazioni citogenetiche (delezione del 13, delezione del 17p e delezione/trisomia del 12), lo stato mutazionale dei geni della catena pesante delle immunoglobuline e l’espressione di molecole come il CD38 e lo ZAP70.
Negli ultimi anni sono stati aggiunti nuovi criteri molecolari per la stratificazione: es
pressione di hCNT1 (human concentrative nucleoside trasporter 1) e hENT1 (equilibrative nucleoside trasporter 1) e WNT 5b.
hCNT1 e hENT1 sono dei trasportatori coinvolti nel metabolismo degli analoghi delle purine (Cladribina e Fludarabina) che vengono usati come chemioterapici.
Lo scopo di questa tesi è quello di valutare tramite REAL-TIME PCR quantitativa l’espressione di questi marcatori, in pazienti affetti da LLC, trattati con anticorpo monoclonale umanizzato Rituximab in associazione con analoghi delle purine e di correlare il livello di espressione con la prognosi e la risposta terapeutica. I risultati potrebbero servire per modulare la somministrazione degli anologhi purinici nei pazienti che presentano determinati livelli di espressione e impostare per ogni paziente una terapia personalizzata anche in base all’espressione di questi nuovi marcatori che potrebbero potenziare quelli di significato prognostico gia’ noto
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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