1,721,030 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
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
Anatomia microcirúrgica de áreas cerebrais da linguagem revisitadas através do mapeamento cerebral em pacientes com gliomas
Get PDFAtualmente, nós sabemos que a teoria localizacionista, baseada em áreas corticais como a área de Broca e área de Wernicke, não consegue explicar o funcionamento da linguagem. Nos últimos anos, muitos estudos demonstraram novas áreas corticais relacionadas à linguagem, esses achados levaram à uma mudança de paradigma de conceitos localizacionistas para uma visão hodotópica. Isto foi possível devido a uma mudança de paradigma no tratamento dos tumores cerebrais, especialmente nos gliomas. Recentemente que a ressecção total ou subtotal de tumores cerebrais com mapeamento cortical e subcortical em pacientes acordados tornou-se o padrão ouro, principalmente em tumores localizados no hemisfério dominante para a fala. Esses novos conceitos são baseados em conexões subcorticais. Assim, os fascículos clássicos são descritos de acordo com suas funções, enquanto novos tratos são relacionados à função da linguagem. A identificação dessas áreas anatômicas e tratos durante a ressecção do tumor permite a preservação das funções às quais eles servem. Neste artigo, nós relatamos os resultados de nossas dissecções anatômicas usando a técnica de Klinger para o estudo das fibras brancas e discutimos essa recente anatomia funcional da linguagem.Currently, we know that the localizationist theory, based on cortical areas such as Broca's area and Wernicke's area, cannot explain how the language function works. In recent years, several studies have demonstrated new cortical areas related to language, largely resulting in a paradigm shift from localizationism to hodotopical concepts. This was possible due to a paradigm change in treating cerebral tumors, especially in low-grade gliomas. Recently that total or subtotal resection of cerebral tumors with cortical and subcortical mapping on awake patients has become the gold standard, chiefly for tumors located on the dominant hemisphere for speech. These new concepts are based on subcortical connections. Thus, classical fasciculi are described according to their functions, while new tracts are related to the language function. The identification of those anatomical areas and tracts during brain tumor resections allows the preservation of the functions they subserve. In this study, we thus reveal the results of our anatomical dissections using the Klinger technique for white fiber studies and discuss this new language anatomy
Anatomia microcirúrgica endoscópica e microscópica dos acessos interhemisféricos anteriores modificados para aneurismas da artéria comunicante anterior
Get PDFIntrodução: A extensa variedade de acessos cirúrgicos tem sido descritos para o tratamento dos aneurismas da artéria comunicante anterior (AComA) porém ainda existe controvérsia como a melhor modo cirúrgico. O acesso interhemisférico anterior (AIA) é preferível para os aneurismas do complexo AComA superiores por permitir a visualização da exposição do aneurisma com uma retração cortical reduzida e menor dissecção. Métodos: Cinco acessos cirúrgicos interhemisféricos anteriores modificados foram realizados em 5 espécimes (10 lados) preparados com látex colorido. Cada área cirúrgica foi explorada por múltiplos cirurgiões utilizando tanto o microscópio quanto o endoscópio e a identificação de importantes referencias cirúrgicas foram avaliadas. Resultados: Nosso estudo forneceu a perspectiva anatômica do complexo AComA vista através de uma perspectiva do acesso interhemisférico anterior. Nós também discutimos as vantagens de cada acesso e as limitações. Conclusão: Nosso estudo confirmou que o acesso interhemisférico anterior permanece como opção para o acesso aos aneurismas da AComA. O entendimento das relações entre as estruturas microcirúrgicas, assim como o uso do endoscópio pode ajudar em diminuir o risco de complicações cirúrgicas.Introduction: A variety of surgical approaches have been described for the treatment of anterior communicating artery (ACoA) aneurysms but there remains controversy as to the best mode of surgical treatment. The anterior interhemispheric approach (AIH) is preferred for high-riding ACoA complex aneurysms as it allows for the visualization and exposure of the aneurysm with reduced cortical retraction and reduced dissection. Our objective is to perform an anatomic comparison between five tailored AIH for ACoA aneurysms. Methods: Five tailored anterior interhemispheric approach were performed on 5 cadaveric heads (10 sides) injected with colored latex. Each surgical area was explored by multiple surgeons using both microsurgical and endoscope, and the identification of important surgical landmarks were evaluated. Results: Our study provided a surgical anatomy comparison of five tailored anterior communicating artery as seen through an anterior interhemispheric perspective. We also discussed about the advantages of each approach and their limitations. Conclusion: Our study confirmed that the anterior interhemispheric approach is still the optimal option for approaching ACoA aneurysms. Understanding the relationships among the microsurgical structures, as well as the use of the endoscope, may help reduce the risk of surgical complications
Influência da abordagem cirúrgica na ressecção dos meningiomas petroclivais
Get PDFMeningiomas petroclivais são tumores da base do crânio desafiadores para ressecção cirúrgica devido a sua localização profunda e relação com estruturas neurovasculares vitais. Geralmente são lesões benignas, mas podem envolver ou infiltrar o osso da base do crânio, dura-máter, tronco encefálico e todas as estruturas neurovasculares desta região, tornando a remoção total difícil sem causar déficits neurológicos. O objetivo deste estudo é revisar uma série de casos de meningiomas petroclivais tratados cirurgicamente em centro de referência de base de crânio, considerando os fatores determinantes para a escolha da abordagem. A casuística foi analisada com coleta retrospectiva dos dados. Devido à dificuldade de acesso, essas lesões geralmente requerem diferentes abordagens cirúrgicas e apresentam dificuldades cirúrgicas distintas. Embora as abordagens fronto-órbito-zigomática, petrosas, incluindo présigmoide retrolabiríntica, translabiríntica e petrosectomia total, e a retrossigmoide sejam as mais utilizadas para ressecção destes tumores, não foi realizado até o presente momento estudo comparativo que determine qual abordagem apresenta maior grau de ressecção cirúrgica associada a menor taxa de morbidade.Petroclival meningiomas are challenging skull base tumors for surgical resection because of its deep location and their relationship to vital neurovascular structures. They are usually benign, but may involve or infiltrate the bone of the skull base, dura, brain stem and all neurovascular structures in this region, making it difficult to completely remove without causing neurological deficits. The aim of this study is to review a surgical series of petroclival meningioma treated in a referral center for skull base tumors, considering the determining factors to the choice of approach. The casuistry was analyzed with retrospective data collection. Due to difficult access, these injuries usually require different surgical approaches and have different surgical difficulties. Although the fronto-orbital-zygomatic, petrous, including retrolabyrinthine pre-sigmoid, translabyrinthine and total petrosectomy, and retrosigmoid are frequently used for resection of these tumors, it has not been realized to date comparative study to determine which approach has greater degree of surgical resection associated with lower morbidity rate
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
- …
