1,720,960 research outputs found
ABCA-1 Expression is reduced in atherosclerotic plaques of hypertensive patient: a new link between hypertension and atherosclerosis
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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
MicroRNA profiling reveals new potential modulators of insulin-resistance and cardiovascular risk in type 2 diabetes
No full textBackground: Type 2 Diabetes (T2DM) is a chronic disease characterized
by an inadequate beta-cell response to the progressive insulin
resistance. The tiny mechanism(s) underlying insulin-resistance and
increased atherosclerosis burden in T2DM patients are not fully
understood. MicroRNAs (miRNAs) are short (20–22 nucleotides of
length), endogenous, non-coding, RNAs representing a new class of
regulators of gene expression. Remarkably, they are found in all cell
type and their presence is clearly detectable in peripheral blood.
Currently miRNAs involvement has been demonstrated in many
diseases such as cancer, inflammatory and cardiovascular diseases.
However, the role of miRNAs in T2DM in humans is not fully elucidated,
thus aim of this study was to investigate the plasma miRNAs
profile of diabetic patients.
Materials and Methods: Blood samples were collected from 11
diabetic patients and 11 matched control patients. T2DM diagnosis
was formulated according currently available American Diabetes
Association guidelines. We enrolled only drug-naı ̈ve patients before
starting specific treatment. Patients with active inflammatory diseases,
chronic kidney disease and cancer were excluded. RNA was extracted
according with previously validated methods, quantified and pooled
and a wide microRNA expression profiling was performed (miRNome).
Then, some of the miRNAs that were differently expressed
between two groups were validated by RealTime-PCR (RT-PCR).
Data analyses were performed with deltadelta Ct method. Finally,
bioinformatics was used in order to identify the potential targets of
these miRNAs.
Results: Microarray analysis showed that 4 miRNAs were upregulated
whereas 21 miRNAs were downregulated in diabetic patients.
Interestingly, RT-PCR validation confirmed a significant downregulation
of let-7a (p = 0.023) and let-7f (p = 0.049). Moreover, we
found a significant upregulation of miR-326 (p = 0.006). Furthermore,
an interesting trend supporting down-regulation of miR-16,
miR-21 and let-7 g in diabetic patients was found, despite these
values did not reach statistical significance probably due the small
study population. In silico analysis of predicted targets confirmed that
these miRNAs may modulate genes greatly involved in insulin-signaling
(including Adiponectin, IGF-1 receptor and others),
endothelial function (including PTEN) and linked to cardiovascular
risk (including VLDL receptor, TGF-beta).
Conclusion: This study demonstrated that diabetes is associated with
a modulation of the expression of plasma miRNA that are involved in
insulin resistance and endothelial function. Further studies on these specific miRNAs’ targets are required to understand the molecular
read-out of this modulation. If confirmed, these findings will contribute
to improve our knowledge on diabetes pathophysiology and
lead to the identification of new innovative therapeutic strategies for
T2DM
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
MicroRNA profiling reveals new potential modulators of insulin-resistance in type 2 Diabetes
No full textBackground: Type 2 Diabetes (T2DM) is a chronic disease characterized by an inadequate beta-cell response to the progressive insulin resistance. The tiny mechanism(s) underlying insulin-resistance and increased atherosclerosis burden in T2DM patients are not fully understood. MicroRNAs (miRNAs) are short (20-22 nucleotides of length), endogenous, non-coding, RNAs representing a new class of regulators of gene expression. Remarkably, they are found in all cell type and their presence is clearly detectable in peripheral blood. Currently miRNAs involvement has been demonstrated in many diseases such as cancer, inflammatory and cardiovascular diseases. However, the role of miRNAs in T2DM in humans is not fully elucidated, thus aim of this study was to investigate the plasma miRNAs profile of diabetic patients.
Materials and Methods: blood samples were collected from 11 diabetic patients and 11 matched control patients. T2DM diagnosis was formulated according currently available American Diabetes Association guidelines. We enrolled only drug-naïve patients before starting specific treatment. Patients with active inflammatory diseases, chronic kidney disease and cancer were excluded. RNA was extracted according with previously validated methods, quantified and pooled and a wide microRNA expression profiling was performed (miRNome). Then, some of the miRNAs that were differently expressed between two groups were validated by RealTime-PCR (RT-PCR). Data analyses were performed with deltadelta Ct method. Finally, bioinformatics was used in order to identify the potential targets of these miRNAs.
Results: microarray analysis showed that 4 miRNAs were upregulated whereas 21 miRNAs were downregulated in diabetic patients. Interestingly, RT-PCR validation confirmed a significant downregulation of let-7a (p=0.023) and let-7f (p=0.049). Moreover, we found a significant upregulation of miR-326 (p=0.006). Furthermore, an interesting trend supporting down-regulation of miR-16, miR-21 and let-7g in diabetic patients was found, despite these values did not reach statistical significance probably due the small study population. In silico analysis confirmed that the predicted targets of these miRNAs are able to modulate genes involved in insulin-sensitivity, including Adiponectin and IGF-1 receptor.
Conclusion: this study demonstrated that diabetes is associated with a modulation of the expression of plasma miRNA that are involved in insulin resistance. If confirmed, these findings will contribute to improve our knowledge on diabetes pathophysiology and lead to the identification of new innovative therapeutic approach
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