1,721,105 research outputs found
Eveline, Elsie, and the politics of paralysis: Echoes of Dubliners in Zoë Wicomb’s “Nothing Like the Wind”
No full textThis article discusses the presence of a covert but substantial Joycean intertext in Zoë Wicomb’s short story “Nothing Like the Wind”, namely “Eveline” in Dubliners. The two texts tackle similarly the felt experience of their female protagonists, Elsie and Eveline, two colonial or colonized subjects suffering equally because of their physical location, gender, and social class. Apart from the parallels at the level of both content and form, the short stories perform a dialogue centred around the staple thematic concerns of patriarchal family, home, and emigration — over which the paralytic legacy of colonialism hovers. Wicomb’s engagement with these issues finds a ready counterpart in Joyce’s own treatment of British policies in Ireland. This intertextual connection sheds new light on the possibilities of interpretation, both of “Nothing Like the Wind” and of “Eveline”
MECHANISMS OF PROTEIN TRANSPORT AT THE ER-GOLGI INTERFACE
Full text linkThe Endoplasmic Reticulum represents the first station of the secretory path-way, where proteins destined to the cell surface or to some intracellular organelles are recruited in specific ER subdomains, the ER Exit Sites (ERES), and start to travel into transport carriers to reach the proper final destination. Even though cargoes are usual-ly recruited to ERES by a sequence-dependent mechanism, it is known that other fac-tors contribute to protein export from the ER. Using model fluorescent tail-anchored proteins our group previously demonstrated that the length/hydrophobicity of the transmembrane domain is an important factor determining recruitment to or exclusion from ERES: a protein with a short TMD (FP-17) is excluded from ERES and retained in the ER, while a longer TMD (FP-22) determines enrichment in ERES. In order to clarify the molecular mechanism underlying this TMD-dependent transport, we first compared the transport of an export signal-bearing (VSV-G DxE) membrane protein with our model protein FP22, which lacks an export signal. FP22 and VSV-G accu-mulate together at ERES, but VSVG reaches the plasma membrane more rapidly than FP22. To investigate the basis of this difference, we combined cDNA microinjection to temperature blocks and live-cell imaging approaches that allowed us to analyze the transport at early steps of the secretory pathway at the ER-Golgi interface. At 20°C, a temperature at which only the transport between the ER and the Golgi is allowed, all of the VSVG accumulates in the Golgi, while FP-22 remains distributed between the ER and the Golgi. After bleaching the Golgi fraction of FP22 we observed a rapid, energy-dependent, fluorescence recovery, indicating an efficient ER to Golgi transport even in the absence of the export signal and suggesting that FP22 may be re-cycled between the two compartments. In agreement, a rapid emptying of the Golgi was observed after ER bleaching (accompanied by a fluorescence recovery of the ER fraction). To investigate whether this phenomenon is restricted to our model protein only or it is more general event, we then tested the behavior of a signal-deleted form of VSV-G (VSV-G AxA). Similarly to FP22, VSVG AxA is distributed between the Golgi and the ER at 20°C and Golgi fluorescence rapidly decreases after ER bleach-ing, suggesting a new role of the ER export signal, which is important not only in re-cruiting cargoes at the ERES, but also in preventing their recruitment into futile cy-cles between the Golgi and the ER, which delay their arrival to the cell surface.
To further characterize the mechanism of TMD-dependent sorting, we then in-vestigated the role of membrane curvature; our group previously demonstrated that FP-22 is segregated from FP-17 in specific ER subdomains, which are characterized by membrane curvature (ERES and ER tubules). In collaboration with Bruno Goud and Jean-Baptiste Manneville (Institute Curie, Paris), we created highly curved do-mains using membranes composed of a uniform lipid composition (POPC, palmitoyl-oleyl-phosphatidylcholine) or ER lipids extracted from rat liver microsomes, and we analyzed the distribution of our two model proteins in flat and curved domains. Our results indicate that the two proteins are uniformly distributed in curved membranes and strongly suggest that the membrane curvature alone cannot drive the TMD-dependent partitioning of membrane proteins in ERES and ER tubules.
Taken together, our data contribute to clarify the role of two fundamental fac-tors influencing the transport of membrane proteins along the secretory pathway that were never investigated before
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
Analisi della propagazione di cricche in pannelli a struttura integrale
No full textI componenti a struttura integrale (monolitica) possono assumere un ruolo fondamentale nella progettazione strutturale ad alta efficienza; infatti, considerando l’attuale stato dell’arte delle procedure tecnologiche di fabbricazione, le strutture integrali possono risultare efficaci nell’abbattimento dei costi di realizzazione e soprattutto nella riduzione del peso. Ci sono però importanti aspetti relativi all’integrità strutturale che ne hanno limitato l’uso fino ad ora. Le strutture convenzionali che usano
sistemi di giunzione meccanica o tramite incollaggio offrono indubbi vantaggi in termini di comportamento damage tolerant e fail safe. In particolare, nelle strutture aerospaziali la presenza di
due parti distinte, pelli e correnti, aumenta considerevolmente l’affidabilità strutturale del componente in presenza di difetti e cricche propaganti. Scopo di questo lavoro è di illustrare l’applicazione di una metodologia numerica per la determinazione del comportamento di strutture integrali rinforzate, per
uso aerospaziale, in presenza di cricche. L’attività descritta è stata sviluppata in accordo con “Analytical Round Robin on Crack Growth and Residual Strength Prediction in Integral Structures”
proposto da ASTM Task Group E08.04.05; in particolare, nel lavoro descritto sono stati sviluppati modelli ad elementi finiti di diverse tipologie di pannelli integrali, su cui è stata simulata la
propagazione della cricca. La validazione dei modelli numerici, ottenuta usando i dati di propagazione sperimentali, mostra una buona accuratezza delle predizioni
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
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