1,720,960 research outputs found
Pantothenate kinase-2 (Pank2) silencing causes cell growth reduction, cell-specific ferroportin upregulation and iron deregulation
No full textPantothenate kinase 2 (Pank2) is a mitochondrial enzyme that catalyses the first regulatory step of Coenzyme A synthesis and that is responsible for a genetic movement disorder named Pank-associated neurodegeneration (PKAN). This is characterized by abnormal iron accumulation in the brain, particularly in the globus pallidus. We downregulated Pank2 in some cell lines by using specific siRNAs to study its effect on iron homeostasis. In HeLa cells this caused a reduction of cell proliferation and of aconitase activity, signs of cytosolic iron deficiency without mitochondrial iron deposition, and a 12-fold induction of ferroportin mRNA. Pank2 silencing caused a strong induction of ferroportin mRNA also in hepatoma HepG2, a modest one in neuroblastoma SH-SY5Y and none in glioma U373 cells. A reduction of cell growth was observed in all these cell types. The strong Pank2-mediated alteration of ferroportin expression in some cell types might alter iron transfer to the brain and be connected with brain iron accumulation
Pantothenate kinase-2 (Pank2) silencing causes cell growth reduction, cell-specific ferroportin upregulation and iron deregulation
No full textPantothenate kinase 2 (Pank2) is a mitochondrial enzyme that catalyses the first regulatory step of Coenzyme A synthesis and that is responsible for a genetic movement disorder named Pank-associated neurodegeneration (PKAN). This is characterized by abnormal iron accumulation in the brain, particularly in the globus pallidus. We downregulated Pank2 in some cell lines by using specific siRNAs to study its effect on iron homeostasis. In HeLa cells this caused a reduction of cell proliferation and of aconitase activity, signs of cytosolic iron deficiency without mitochondrial iron deposition, and a 12-fold induction of ferroportin mRNA. Pank2 silencing caused a strong induction of ferroportin mRNA also in hepatoma HepG2, a modest one in neuroblastoma SH-SY5Y and none in glioma U373 cells. A reduction of cell growth was observed in all these cell types. The strong Pank2-mediated alteration of ferroportin expression in some cell types might alter iron transfer to the brain and be connected with brain iron accumulation. (C) 2010 Elsevier Inc. All rights reserved
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
Didattica delle lingue in prospectiva interculturale: innovazione e potencialita
No full textDesde principios de los 80 el adjetivo "intercultural" en el aprendizaje de idiomas y la enseñanza ha adquirido una importancia notable, aunque su significado es muy debatido a pesar de la existencia de una vasta literatura sobre este tema, las dificultades surgen cuando se aplica en el aula. El objetivo de este trabajo es analizar los elementos que consideramos pilares centrales en esta metodología: un lenguaje renovado y su relación cultural, la competencia comunicativa intercultural, el hablante intercultural. Estos factores nos permiten considerar un nuevo paradigma en la enseñanza de idiomas y, además, fomentar la creación de nuevas potencialidades y configurar el aula como un ambiente de aprendizaje significativo hacia el descubrimiento de la alteridad
UN PERCORSO DI ITALIANO LS IN PROSPETTIVA INTERCULTURALE
No full textA partire dagli anni ’80 la didattica delle lingue straniere è stata influenzata in modocrescente dalla prospettiva interculturale: su di essa esiste ormai una vasta letteratura,ma il suo esatto significato continua ad essere fonte di intenso dibattito.Cosa si intende per didattica interculturale? Quali strategie didattiche adottare perportare gli studenti all’acquisizione della competenza comunicativa interculturale?Quali proposte per contesti di italiano LS?Questo intervento propone possibili risposte a queste domande attraverso lapresentazione di un percorso didattico sperimentato con studenti messicani, partendodall’ipotesi che per iniziare a sviluppare la competenza comunicativa interculturale,nucleo della didattica in prospettiva interculturale, si debba partire da un lavoro inclasse che porti gli studenti ad assumere consapevolezza del proprio “softwarementale”. Questo lavoro va considerato come passaggio imprescindibile per arrivare acomunicare efficacemente con l’altro diverso da sé
Didattica delle lingue in prospectiva interculturale: innovazione e potencialita
No full textEnsayoDesde principios de los 80 el adjetivo "intercultural" en el aprendizaje de idiomas y la enseñanza ha adquirido una importancia notable, aunque su significado es muy debatido a pesar de la existencia de una vasta literatura sobre este tema, las dificultades surgen cuando se aplica en el aula. El objetivo de este trabajo es analizar los elementos que consideramos pilares centrales en esta metodología: un lenguaje renovado y su relación cultural, la competencia comunicativa intercultural, el hablante intercultural. Estos factores nos permiten considerar un nuevo paradigma en la enseñanza de idiomas y, además, fomentar la creación de nuevas potencialidades y configurar el aula como un ambiente de aprendizaje significativo hacia el descubrimiento de la alteridad.---------Poiché primi anni '80 l'aggettivo "interculturale" per l'apprendimento delle lingue e l'insegnamento è sembrato di acquisire una notevole importanza, anche se il suo significato è fortemente dibattuto. È un dato di fatto, nonostante l'esistenza di una vasta letteratura su questo argomento, le difficoltà sorgono quando si applica in classe. L'obiettivo di questo lavoro è quello di analizzare gli elementi che riteniamo essere i pilastri centrali in questa metodologia, cioè un linguaggio rinnovato rapporto-e-cultura, la competenza comunicativa interculturale, l'oratore interculturale. Questi fattori ci permettono di considerare questo come un nuovo paradigma di insegnamento delle lingue, inoltre, favoriscono la creazione di nuove potenzialità e configurare la classe come un ambiente di apprendimento significativo verso la scoperta dell'Altro.Universidad Nacional Autónoma de Méxic
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
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