1,721,262 research outputs found
Developments in Target Normal Sheath Acceleration theoretical modeling: Ion cut-off energy dependence on target thickness and transverse size
No full text
The potential role of glutamate in the current diabetes epidemic
No full textIn the present article, we propose the perspective that abnormal glutamate homeostasis might contribute to diabetes pathogenesis. Previous reports and our recent data indicate that chronically high extracellular glutamate levels exert direct and indirect effects that might participate in the progressive loss of β-cells occurring in both T1D and T2D. In addition, abnormal glutamate homeostasis may impact all the three accelerators of the "accelerator hypothesis" and could partially explain the rising frequency of T1D and T2D
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
Pancreas endocrino e metabolismo del colesterolo
Full text linkIl diabete di tipo 2 comprende un complesso gruppo di disordini metabolici eterogenei caratterizzati da un deficit di secrezione di insulina accompagnato da insulino-resistenza. E’ spesso associato a dislipidemia che contribuisce sia alla progressiva disfunzione beta-pancreatica sia all’aumentato rischio di complicanze cardiovascolari. Queste ultime rappresentano la principale causa di mortalità nei soggetti diabetici.
Studi condotti in questi anni supportano un ruolo chiave del colesterolo non solo nello sviluppo di complicanze cardiovascolari ma anche direttamente nel controllo della funzionalità beta-pancreatica, fondamentale per garantire la secrezione di insulina e l’omeostasi glicemica. Le cellule beta-pancreatiche sono sensibili alle variazioni di colesterolo ed hanno sviluppato un complesso sistema per controllarne omostaticamente la concentrazione intracellulare.
Dopo una breve introduzione sul pancreas endocrino e sui meccanismi molecolari che sono alla base del controllo della secrezione di insulina, la rassegna prende in esame il metabolismo del colesterolo nella cellula beta-pancreatica ed esamina l’impatto del lipide sulla funzione e disfunzione di questa cellula. Infine, nell’ultima parte, vengono analizzate le evidenze che legano il metabolismo del colesterolo, alla funzionalità beta-pancreatica e al metabolismo glucidico nell’uomo.
La conoscenza degli specifici meccanismi molecolari responsabili del metabolismo e della tossicità del colesterolo nella cellula beta-pancreatica rappresenta un fondamentale obiettivo della ricerca sperimentale per identificare nuovi target di intervento farmacologico per il trattamento del diabete e delle sue complicanze, possibilmente ancora più efficaci e sicuri di quelle ora disponibili.Type 2 diabetes includes a complex of heterogeneous metabolic disorders characterized by a lack
of insulin secretion accompanied by insulin resistance. Dyslipidemia is often associated with both
progressive beta-cell dysfunction and increased risk of cardiovascular complications. The latter are
the main cause of mortality in diabetic subjects. Studies carried out in recent years support a key role
of cholesterol not only in the development of cardiovascular complications, but also directly in the
control of beta-pancreatic function, which is fundamental for ensuring insulin secretion and glycemic
homeostasis. Beta-pancreatic cells are sensitive to changes in cholesterol and have developed a complex
system to control their homeostatic intracellular concentration. After a brief introduction on the
endocrine pancreas and the molecular mechanisms that underlie the control of insulin secretion, the
review examines the metabolism of cholesterol in the beta-pancreatic cell and examines the impact of
lipid on the function and dysfunction of this cell. Finally, in the last part, the evidence linking cholesterol
metabolism, beta-pancreatic function and glucose metabolism in humans are analyzed. Knowledge
of the specific molecular mechanisms of metabolism and cholesterol toxicity in the beta-pancreatic
cell is a fundamental objective of experimental research to identify new targets for pharmacological
intervention for the treatment of diabetes and its complications, possibly even more effective and safe
than those now available
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
- …
