1,721,181 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
Direct conversion of human fibroblasts into striatal neurons by defined factors
No full textDissertação de mestrado apresentada ao Departamento Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de CoimbraNew findings in stem cell research show that it is possible to reprogram a somatic
cell into a pluripotent stem cell, by delivering specific genes. The induction of
pluripotency arouse questions related with the possibility of directly reprogram a somatic
cell into another somatic cell type, also by delivering specific combinations of genes,
without going through a pluripotency state.
Several reports have shown that this direct conversion is possible and in 2010, the
first description of the conversion of mouse fibroblasts into induced neuronal (iN) cells
was published. Since then, it has been established that it is possible to obtain subtype
specific iN cells from human fibroblasts.
This thesis describes a project with the aim of directly convert human fibroblasts
into striatal GABAergic projection neurons, by using a combination of defined
transcription factors with important biological functions in neuronal development and
differentiation of striatal neurons. Since these neurons are specially affected in cases of
Huntington’s disease and stroke, their generation through the direct conversion process
would possibly be a valuable approach to obtain cells that could be used in cellular
therapy, being transplanted into patients’ brains.
In order to maximize the efficiency of neural conversion, a comparative study
including several protocols for the generation of iN cells was also performed.Novas descobertas na área de investigação em células estaminais demonstram ser
possível reprogramar uma célula somática numa célula pluripotente, através da entrega de
genes específicos. Esta indução de pluripotência levantou algumas questões relacionadas
com a possibilidade de converter directamente um determinado tipo célula somática
noutro, também através da entrega de combinações específicas de genes, sem que esta
célula passe por um estado de pluripotência.
Várias publicações demonstraram que esta conversão directa é possível e em 2010,
a primeira descrição da conversão de fibroblastos de rato em células neuronais induzidas
foi publicada. Desde então, foi estabelecido também que é possível obter células neuronais
induzidas, de um determinado sub-tipo, a partir de fibroblastos humanos.
Esta tese descreve um projecto que teve como objectivo converter directamente
fibroblastos humanos em neurónios GABAérgicos estriatais, utilizando uma combinação
de factores de transcrição, com funções biológicas relacionadas sobretudo com o
desenvolvimento neuronal e a diferenciação de neurónios estriatais. Pelo facto de estes
neurónios serem especialmente afectados em casos de doença de Huntington e acidente
vascular cerebral, a sua obtenção através de um processo de conversão directa constituiria
um método de grande valor para a obtenção de células que poderiam ser utilizadas em
terapia celular, servindo como material de transplante em cérebros de pacientes.
De modo a maximizar a eficiência da conversão neuronal, um estudo comparativo
envolvendo diferentes protocolos para a obtenção de células neuronais induzidas foi
também realizado
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
Advances, challenges, and opportunities of human midbrain organoids for modelling of the dopaminergic system
Full text linkDopaminergic neurons in the ventral midbrain are critical for regulating movement, cognition, and emotion. Ventral midbrain organoids can be used to model both development and diseases of the dopaminergic system, especially Parkinson’s disease. Here, we summarize recent advances and remaining challenges in developing such three-dimensional organoids from human pluripotent stem cells. We outline how ventral midbrain organoid systems have progressed from early three-dimensional culture models to sophisticated, engineered, multiregional systems that more accurately replicate the complex network of dopaminergic neurons. Furthermore, we examine how the development of organoid models from other brain regions, particularly the forebrain, provides complementary insights that can accelerate progress also in the field of midbrain organoids, towards the generation of more advanced in vitro systems for midbrain dopaminergic neurons and their circuitry. Such cutting-edge human stem cell-based models offer powerful platforms for investigating dopaminergic neuron generation, function, and connectivity, thereby enhancing disease modelling, drug discovery, and the development of targeted cell-based therapies
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
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