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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
GSK3β down-regulation in Mesenchymal Stem Cells from patients with Myelodysplastic Syndrome.
No full textIn addition to neoplastic transformation of hematopoietic progenitors,bone marrow microenvironment damages can contribute to myeloid neoplasms development and maintenance. Several functional and morphological abnormalities of bone marrow mesenchymal stromal cells (BM-MSC) have been described in myeloid neoplasms. Nevertheless, molecular bases of differences between MSCs from normal and leukemic/myelodysplastic bone marrows are still unknown. Deregulation of genes belonging to PI3K/AKT signaling pathway has been
described in MSC from different type of cancers. We studied the expression
profile of genes belonging to PI3K/AKT signaling pathway in MSCs from 40 patients including 10 de novo AML, 10 de novo MDS, 10 t-MN (therapy-related myeloid neoplasms) and 10 patients with limited stage lymphoma without bone marrow involvement (used as normal control). BM-MSCs were obtained by Ficoll-gradient centrifugation
of bone marrow samples and cultured up to 70% confluence in MesenCult Medium. Cells at 2nd passage were used for all experiments. The Human PI3K-AKT PCR array (SABioscience) was used to analyze mRNA levels of 84 key genes involved in PI3K-AKT signaling pathway, comparing 5 de novo AML, 5 de novo MDS and 5 t-MN vs 5 normal
bone marrows. Relative changes in gene expression were calculated using the DDCt method. Fold change variations ≥1.5 in association to statistically significant T-test (p-value≤ 0.05) were used for the statistical analysis. Genes resulted significantly deregulated were validated by
quantitative real time RT-PCR, in 10 de novo AML samples, 10 de novo
MDS, 10 t-MN and 10 normal controls. Total GSK3b protein level and
its Ser-9 phosphorylated isoform were measured by Western blot in a
subgroup of MDS patients and controls. PI3K-AKT PCR arrays revealed
a significantly down-regulation of GSK3b, MTCP1, RASA1 and SOS1
genes in MSC from all leukemic and myelodysplastic bone marrows
compared to control group. After validation, all genes were confirmed
as significantly down-regulated in de novo MDS samples respect to normal
controls: GSK3b (p=0.0056, FC=-1.94), RASA1 (p =0.0044, FC=-2.19), SOS1 (p=0.0047, FC=-1.9) and MTCP1 (p=0.0026, FC=-1.93). No significant differences were found in the expression levels of studied
genes in the validation group among de novo AML, t-MN and controls.
Western blot analysis confirmed the down-regulation of both GSK3b
total protein and of its Ser-9 phosphorylated isoform in MDS MSC
respect to controls. Deregulation of genes belonging to PI3K/AKT signaling
pathway may contribute to MSC dysfunction described in MDS
bone marrows and can affect their ability to interact with normal
hematopoietic cells, participating to bone marrow failure and
myelodysplastic development. GSK3b, a crucial regulatory kinase interacting
with multiple signaling pathways, is one of the most significantly
down-regulated genes in MSC from myelodysplastic bone marrows
and its functional significance is under investigation
Variations on the Author
Get PDF“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
DEREGULATION OF PI3K/AKT SIGNALING IN BONE MARROW MESENCHIMAL STROMAL CELLS FROM PATIENTS WITH DE NOVO AND THERAPY-RELATED ACUTE MYELOID LEUKEMIA
No full textBackground: In addition to neoplastic transformation of hematopoietic progenitors,
a damage of bone marrow microenvironment can contribute to leukemia
development and maintenance. Several functional and morphological abnormalities
of bone marrow mesenchimal stromal cells (BM-MSCs) have been
described in myeloid neoplasms. Nevertheless molecular bases of differences
between MSCs from normal and leukemic bone marrows are still unknown.
PI3K/AKT signaling pathway is involved in several MSC functions and deregulation
of genes belonging to these pathways have been described in MSCs
from different type of cancers.
Aims: To study the expression profile of genes belonging to PI3K/AKT signaling
pathway in MSCs from patients with de novo and therapy related Acute
Myeloid Leukemia (t-AML), using as normal counterpart BM-MSCs isolated
from patients with limited stage lymphoma without bone marrow involvement.
Methods: Study population included 5 patients with limited stage diffuse large
B cell lymphoma (DLBCL) without bone marrow involvement, as normal control,
and 10 patients with AML, including 5 de novo and 5 therapy-related cases.
Bone marrow mononuclear cells were obtained by Ficoll-gradient centrifugation
of bone marrow samples and cultured in Complete Human MesenCultR
Medium (Stem Cell Technologies) in 25 cm2 flask at 37°C. After 24 hours nonadherent
cells were removed and adherent cells were cultured up to 70% confluence,
then trypsinized and passed to a new flask. Cells at 2nd passage were
collected by trypsinization, RNA was extracted using RNase mini kit (Qiagen)
and cDNA was synthesized by QuantiTect Reverse Transcription kit (Qiagen).
The Human PI3K-AKT PCR array (RT2ProfilerTM PCR Array; SABioscience)
was used to analyze mRNA levels of 84 key genes involved in PI3K-AKT Signaling
Pathway, in a 96-well plate in the CFX96 thermocycler (Bio-Rad). Relative
changes in gene expression were calculated using the ΔΔCt method. An
average Ct value of five housekeeping genes (GAPDH, βactin, β2-microglobulin,
HPRT1 and RPLPO) was used to normalize the gene expression between
sample groups. Fold change (FC) variations ≥1.5 in association to statistically
significant T-test (P-value≤0.05) were used for the statistical analysis.
Results: Comparison of MSCs from AML samples versus normal controls
identified three genes significantly down-regulated in leukemic samples, including
GSK3B (P=0.0002, FC=-1.56), MTCP1 (P=0.019, FC=-1.62) and RASA1
(P=0.013, FC=-1.58). Stratifying the analysis according to AML subtypes, three
genes were significantly down-regulated in t-AML versus normal bone marrow,
including GSK3B (P=0.0009 and FC=-1.63), PTEN (P=0.004 and FC=-1.50)
and SOS1 (P=0.004 and FC=-1.50). Similarly when comparing MSC from de
novo AML versus normal bone marrow, GSK3B, MTCP1 and RASA1 resulted
still down-regulated in MSC from leukemic samples (P=0.005 and FC=-1.51;
P=0.018 and FC=-1.96; P=0.007 and FC=-1.81, respectively). No differences
were found in the expression levels of studied genes between de novo and therapy-
related AML.
Summary and Conclusions: Deregulation of genes belonging to PI3K/AKT
signaling pathway may contribute to MSC dysfunction described in leukemic
bone marrows and can affect their ability to interact with leukemic blasts and
normal hematopoietic cells, eventually contributing to bone marrow failure and
leukemia development. GSK3B was the most significantly and commonly
down-regulated gene in MSCs from leukemic samples and codifies for the serine/
threonine protein kinase Gsk3β which is also involved in additional signaling
pathways, such as Raf/Mek/Erk and Wnt/β-catenin
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Get PDFWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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