1,721,426 research outputs found
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
Kanser Moleküler Biyolojisi
No full textNormal dokularda ve hücre kültürlerinde çoğalma sırasında hücre-hücre teması oluştuğunda hücre çoğalması baskılanır. Hücrelertek tabaka halinde ürerler ve bu durum hem laboratuar ortamı için(in vitro) hem de çok hücreli canlılar (in vivo) için geçerlidir. Yara iyileşmesi buna iyi bir örnektir. Bu duruma “kontakt inhibisyon” denir.Normal dokuların dengesinin ve yapısının korunmasında gereklibir mekanizmadır. Tümör gelişiminde ise bu durum tümü ile bozulur.1 Kırk yıldır bilinmekte olan kontakt inhibisyonun işlevsel yapısıgünümüzde aydınlatılmaya başlamıştır. Kanserleşmiş hücre, kanserdokusunu oluşturma sürecinde çoğalma yeteneği kazanma işlevi yanısıra çoğalmayı önleyici durumlardan kaçma yeteneği de kazanmaktadır. Büyüme önleyici mekanizmalardan kaçma olarak adlandırılanbu durum, kanser hücrelerine büyüme faktörlerinden bağımsızlık yeteneği olarak yansımaktadır. Büyüme önleyici sinyal yolaklarını başlatan bu moleküller tümör baskılayıcı genler (TBG) olarak adlandırdığımız 20’den fazla gen tarafından kodlanan farklı proteinlerdir. Tümörgelişimini önleyen bu moleküller birbirinden farklı olsa da genel birisimle anılırlar.2 Büyüme önleyici sistemleri, gerektiğinde, doğru zamanda ve yerde çalıştırırlar. Kanserli hücrelerde tümör süpresörlerinaktivitesi genelde mutasyonla azalmıştır. Kanser hücreleri büyümereseptörlerine uyarı gelmeden (ligand-reseptör bağlanması olmadan) reseptörün sürekli kendiliğinden uyarılması gibi mekanizmalarlabüyüme sinyali alır duruma gelmektedir. Kazandığı bu yetenek sinyal yolaklarının, sürekli uyarılmış kalmasına yol açmaktadır. Büyümereseptörlerinin ligandları, büyüme faktörleridir. Bu faktörler, kökenaldığı organa ya da işlevine göre farklı isimler almaktadırlar3</p
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
Prognostic significance of cell proliferation and apoptosis-regulating proteins in epstein-barr virus positive and negative pediatric hodgkin and non-hodgkin's lymphoma
No full textPediatrik HL ve NHL patogenezinde apoptoz, proliferasyon, EBV iliskisi güncel arastırılmaktadır. Antiapoptotik Bcl-2, proapoptotik bax, apoptoz inhibitör protein survivin, ekstrensek apoptoz yolagı reseptörü fas, tümör süpresör p53 apoptoz iliskili faktörlerdir. C-myc hücre siklusunun G1-S faz geçisinde etkin bir onkogen, ki-67 G1-S-G2-M fazlarında eksprese olan proliferasyon belirleyicisidir. Bu çalısmanın amacı pediatrik HL ve NHL'da EBV, proliferasyon, apoptoz ve iliskili faktörlerin patogenez ve prognozdaki rolünü arastırmaktır. EBV-EBER, LMP-1, ki-67, bcl-2, bax, survivin, p53, c-myc, fas, in-situ TUNEL yöntemi ile apoptotik indeks(A_x0003_) 63 HL, 70 NHL'da arastırılmıstır. Bulgularla klinik veriler Ki-kare, Mann Whitney U, Pearson korelasyon, Kaplan Meier sagkalım analizleriyle istatistiksel degerlendirilmistir. HL olgularının yas ortalaması 8.46'dır. Otuziki erken, 31 geç evre olguda dört exitus, altı rekürrens saptanmıstır. Genel sagkalım %94, olaysız sagkalım %83.6' dır. EBV %82.5, bax %74.6, bcl-2 %47.6, survivin %43, p53 %33.3, fas %54 ve c-myc %25.4 pozitiftir. A_x0003_ ortalama %18,22, proliferasyon indeksi %57,83'dür. EBV ile proliferasyon indeksi pozitif, A_x0003_ ters iliskiliæ bax, bcl-2, survivin, p53, fas, c-myc iliskisiz bulunmustur. Tüm parametreler sagkalım iliskisizdir. NHL olgularının yas ortalaması 7.16'dır. Erken evre yedi, ileri evre 63 olgunun, onunda exitus, dördünde rekürrens vardır. Genel sagkalım %82, olaysız sagkalım %75'tir. EBV %25.7, bax %40, bcl-2 %50, survivin %42,9, p53 %8,6, fas %18,6, c-myc %45,7 pozitiftir. A_x0003_ ortalama 131,29/5000 hücre, PI %55,97'dir. EBV fasla iliskili, bcl-2 ile ters iliskilidir. Diger faktörlerle iliskisizdir. Hiçbir faktör sagkalım belirleyicisi degildir. Sonuçlarımız EBV'nin pediatrik HL patogenezinde proliferatif aktiviteyi tetikleyip apoptozu önleyerek rol oynayabilecegi desteklemektedir, ancak prognoz belirleyici degildir. Pediatrik NHL serimizde bulgular EBV'nin patogenezde öncelikli etkili olmadıgını desteklemektedir. Apoptosis, proliferation and relationship with EBV is a contemporary issue in the pathogenesis of HL and NHL. Antiapoptotic bcl-2, proapoptotic bax, inhibitor of apoptosis protein survivin, extrensec apoptotic pathway receptor fas, tumor supressor gene product p53 are apoptosisrelated proteins. C-myc is an oncogene that plays a role in cell-cycle G1-S pass. Ki 67 is a proliferation marker expressed in G1, S, G2, M phases of cell-cycle. In this study prognostic or pathogenetic role of EBV, proliferating activity, apoptosis and regulating proteins in pediatric HL and NHL were explored. EBV-EBER, lmp-1, ki-67, Bcl-2, survivin, Bax, fas, c-myc, p53 and AI detected by in-situ TUNEL method were explored in.63 HL and 70 NHL cases Statistical evaluation was done by chisquare, Mann Whitney U test, Pearson Correlation and Kaplan Meier survival analysis. The mean age of HL cases was 8.46. Among 32 early and 31 advanced stage cases exitus was observed in four and relapse in six cases. Overall survival was 94% and event free survival 83.6%. EBV was positive in 82.5%, bax in 74.6%, bcl-2 in 47.6%, survivin in 43%, p53 in 33.3%, fas in 54% and c-myc in 25.4% cases. Mean AI was 18,22%. Mean proliferation index(PI) was 57,83%. EBV was positively related with PI and negatively with AI, not with bax, bcl-2, survivin, p53, fas and c-myc. None of the parameters were related with prognosis. The mean age of NHL cases was 7.16. Among seven early stage and 63 advenced stage cases exitus was observed in 10 cases and relapse in four cases. Overall survival was 82%, while event free survival was 75%. EBV was positive in 25.7%, bax in 40%, bcl-2 in 50%, survivin in 42,9%, p53 in 8,6%, fas in 18,6% ve c-myc 45,7%. Mean AI was 131,29/5000 cells, mean PI was 55,97%. EBV was related with fas and negatively related with bcl-2, not ralated by other factors. None of the parameters were related with prognosis. Our results suggest that EBV might play a role in HL pathogenesis by inducing proliferative activity and by inhibiting apoptosis but does not predict prognosis. Our results of pediatric NHL series indicate that EBV does not have a primary role in the pathogenesis
Future aspects of immunotherapy and gene therapy in neuroblastoma
No full textImmunotherapy against cancer aims at stimulating the immune system or building an immune response against targeted tumor-associated antigens (TAAs). It was proposed theoretically as a potential therapy for cancer over a century ago but it became popular in the past two decades. Gene therapy represents a promising approach for reversing the neoplastic phenotype or driving tumor cells to self-destruction. Although survival rates of neuroblastoma (NB) with biologically favorable disease are greater than 90%, outcomes of patients with high risk disease are less than 40%. Stage 4 metastatic NB cases over 18 months of age are often incurable with multimodality chemotherapy regimens. In this article, translation of immuno-gene therapy strategies into clinical trials for NB are reviewed. Future aspects of immuno-gene therapy are discussed. © 2009 Zerbinis Medical Publications
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