1,720,972 research outputs found
Linking mitochondria to different human disorders: implication of mitophagy in LHON disease and characterization of the mitochondrial Ca2+ regulator MCUb in cancer progression
No full textCa2+ homeostasis and Ca2+ signal perform a central role in modulating several cellular responses, such as motility, muscle contraction, fertilization, exocytosis, proliferation, and apoptosis. It is not surprising that, being involved in all these crucial processes, intracellular Ca2+ manipulation by numerous proteins can lead to dysfunctions. An essential organelle which has a protagonist role in calcium homeostasis regulation and in most of the previous mentioned cellular processes is undoubtedly the mitochondria. Mitochondrial dysfunctions have been found to be associated with several disorders such as neurodegenerative diseases, aging, and cancer. In this thesis work, we investigated mitochondrial dynamics in the context of an important optic neuropathy and in cell cycle progression. In particular, we explored the role of autophagic and compartment-specific mitophagic activity in Leber's hereditary optic neuropathy (LHON) finding that this degradative process represents a primary target for blocking the progressive optic nerve degeneration and the consequent reduction of vision typical of this neuropathy. Concerning cell cycle, with this work, we place the mitochondria at the center of a [Ca2+]c buffering action that allows the correct progression through the cell cycle, and we assign for the first time a potential oncogenic connotation to the MCU complex dominant-negative subunit MCUb. Taken together, these data remark the importance of this fascinating organelle, clarifies some relationships between mitochondria, calcium signaling, and cell physiology and provide a new starting point for future investigations aimed at identifying new therapies for and against mitochondrial-mediated cell death.L'omeostasi ed il segnale calcio svolgono un ruolo fondamentale nella modulazione di diversi processi cellulari quali motilità, contrazione muscolare, fecondazione, esocitosi, proliferazione ed apoptosi. Prendendo parte a questo gran numero di processi essenziali per la cellula, non stupisce il fatto che la manipolazione intracellulare dello ione calcio da parte di numerose proteine porti a disfunzioni. Il mitocondrio è senza alcun dubbio uno dei più importanti organelli intracellulari, e gioca un ruolo da protagonista nella regolazione dell'omeostasi del calcio e nella maggior parte dei processi cellulari precedentemente citati. Negli ultimi anni sono emerse molte evidenze che hanno messo in relazione alcune disfunzioni mitocondriali a diversi disturbi, quali ad esempio malattie neurodegenerative, invecchiamento e cancro. Questo lavoro di tesi ha avuto come obiettivo primario la valutazione di parametri di fisiologia mitocondriale nel contesto di un'importante neuropatia ottica e nella progressione del ciclo cellulare. In particolare, abbiamo valutato il contributo dell'attività autofagica e mitofagica nella neuropatia ottica ereditaria di Leber (LHON), assegnando un ruolo chiave a questo processo degradativo. Abbiamo evidenziato come la mitofagia potrebbe rappresentare un importante target per il blocco della degenerazione progressiva del nervo ottico e la conseguente riduzione della visione, tipica di questa neuropatia. Per quanto concerne il ciclo cellulare, questo lavoro di tesi attribuisce ai mitocondri la regolazione di un'importante azione tampone che agisce nelle oscillazioni della [Ca2+]c e che consente la corretta divisione cellulare. Abbiamo proposto altresì per la prima volta una potenziale connotazione oncogenica alla proteina MCUb, una subunità componente l’uniporto mitocondriale per il calcio (MCU). Nell’insieme, questi dati sottolineano e confermano l'importanza di questo particolare organello intracellulare, chiariscono alcune relazioni tra mitocondri, segnale calcio e fisiologia cellulare e forniscono un nuovo punto di partenza per indagini future volte a identificare nuove terapie a favore e contro la morte cellulare mitocondrio-mediata
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
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
Calcium Dynamics as a Machine for Decoding Signals
No full textCalcium (Ca2+) is considered one of the most-important biological cations, because it is implicated in cell physiopathology and cell fate through a finely tuned signaling system. In support of this notion, Ca2+is the primary driver of cell proliferation and cell growth; however, it is also intimately linked to cell death. Functional abnormalities or mutations in proteins that mediate Ca2+homeostasis usually lead to a plethora of diseases and pathogenic states, including cancer, heart failure, diabetes, and neurodegenerative disease. In this review, we examine recent discoveries in the highly localized nature of Ca2+-dependent signal transduction and its roles in cell fate, inflammasome activation, and synaptic transmission
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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