Felipe Ortega

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The adult mouse subependymal zone (SEZ) harbours adult neural stem cells (aNSCs) that give rise to neuronal and oligodendroglial progeny. However it is not known whether the same aNSC can give rise to neuronal and oligodendroglial progeny or whether these distinct progenies constitute entirely separate lineages. Continuous live imaging and single-cell(More)
Wikipedia is one of the most successful examples of massive collaborative content development. However, many of the mechanisms and procedures that it uses are still unknown in detail. For instance, how equal (or unequal) are the contributions to it has been discussed in the last years, with no conclusive results. In this paper, we study exactly that aspect(More)
Is there a bias against women’s representation in Wikipedia biographies? Thousands of biographical subjects from six sources are compared against the English-language Wikipedia and the online Encyclopædia Britannica with respect to coverage, gender representation, and article length. We conclude that Wikipedia provides better coverage and longer articles,(More)
Reprogramming of somatic cells into neurons provides a new approach toward cell-based therapy of neurodegenerative diseases. A major challenge for the translation of neuronal reprogramming into therapy is whether the adult human brain contains cell populations amenable to direct somatic cell conversion. Here we show that cells from the adult human cerebral(More)
Glycogen synthase kinase-3 (GSK3) is a key player in the regulation of neuronal survival. Herein, we report evidence of an interaction between P2X7 receptors with NMDA and BDNF receptors at the level of GSK3 signalling and neuroprotection. The activation of these receptors in granule neurons led to a sustained pattern of GSK3 phosphorylation that was mainly(More)
Despite the widespread interest in direct neuronal reprogramming, the mechanisms underpinning fate conversion remain largely unknown. Our study revealed a critical time point after which cells either successfully convert into neurons or succumb to cell death. Co-transduction with Bcl-2 greatly improved negotiation of this critical point by faster neuronal(More)
In this study we report the coupling of nucleotide receptors to GSK-3 signalling, a relevant survival pathway in cerebellar granule neurons. P2X7 agonist BzATP induced a 3–4-fold increase in GSK-3 phosphorylation, which is reported to be associated with the catalytic activity inhibition. This effect was dependent on extracellular calcium and PKC, and(More)
An understanding of participation dynamics within online production communities requires an examination of the roles assumed by participants. Recent studies have established that the organizational structure of such communities is not flat; rather, participants can take on a variety of well-defined functional roles. What is the nature of functional roles?(More)
The creation and maintenance of online production communities depend on the complex ecology created by the interaction of social roles, and these roles are essential for the governance of the community. This study investigates the organizational structure of one of the most notable peerproduction projects: Wikipedia. While online communities have often been(More)
Developer turnover can result in a major problem when developing software. When senior developers abandon a software project, they leave a knowledge gap that has to be managed. In addition, new (junior) developers require some time in order to achieve the desired level of productivity. In this paper, we present a methodology to measure the effect of(More)