186,538 research outputs found
Mesenchymal Differentiation and Organ Distribution of Established Human Stromal Cell Lines in NOD/SCID Mice
No full textTwo human stromal cell lines were established previously from bone marrow-derived primary long-term cultures by immortalization using the SV40 large T antigen and cellular cloning. After irradiation, the fibroblast-like cell lines L87/4 and L88/5 support hematopoietic differentiation of allogeneic cord blood cells in vitro. The stromal cells do not express CD34 and CD50, but some adhesion molecules and integrins, such as CD44, CD54 and CD58. Their expression profiles on RNA and protein levels are suggestive of their osteogenic potency. The quality and quantity of osteocalcin and osteopontin protein expression depended on the culture conditions. Expression of the osteogenic markers increased over time in culture, especially in cells growing in clusters. The stromal cells also expressed collagens I and V, but did not show any expression of collagens II and III. The potentially osteoblastic stromal cells were transplanted into NOD/SCID recipient mice by intravenous injection and were found in various mesenchymal organs up to 10 weeks after transplantation. Osteocalcin-positive human stromal cells could be detected in the bone marrow, thymus, liver, brain and gut of the recipient animals. In summary, there is evidence that human bone-marrow-derived stromal cells have to be considered mesenchymal progenitors, persistently expressing osteogenic markers in vitro and in vivo. Copyright (C) 2001 S, Karger AG, Basel
Anatomy of Gossamer superconductivity
No full textHaas S, Maki K, Dahm T, Thalmeier P. Anatomy of Gossamer superconductivity. Current Applied Physics. 2007;7(1):64-67.There are many systems in which two order parameters compete with each other. Of particular interest are systems in which these order parameters are both unconventional. In this contribution, we examine the representative example of a d-wave superconductor in the presence of a d-wave density wave, which has been suggested as a model for the pseudogap phase in the high-T-c superconductors. The physical properties of unconventional superconductivity in the presence of an anisotropic charge density wave are investigated within mean field theory. This model describes many features that were anticipated by an earlier phenomenological treatment of Tallon and Loram. In addition, the quasiparticle density of states in the presence of these two order parameters is calculated, which should be accessible by scanning tunneling microscopy. (c) 2006 Elsevier B.V. All rights reserved
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
"Stem cell candidates" purified by liquid culture in the presence of Steel factor, IL-3, and 5FU are strictly stroma-dependent and have myeloid, lymphoid, and megakaryocytic potential
No full textBerardi et al. (Science 1995; 267:105) reported recently that combined cytokine stimulation and antimetabolite treatment were able to isolate cells with characteristics of hemopoietic stem cells. Bone marrow (BM) low-density cells were cultured for 1 week in the presence of Steel factor (SF), IL-3, and the antimetabolite 5-FU. Following this approach one in 10(5) BM cells were purified. These cells showed no clonogenic potential in soft gel assays but presented a striking myeloid-lymphoid potential as long-term culture-initiating cells (LTC-ICs). We investigated this new "stem cell candidate." following a similar approach we purified one in 55,000/130,000 cells from cord blood and peripheral blood in mobilized cancer patients. These cells displayed no clonogenic potential in methylcellulose assays in the presence of different cytokine combinations and generated very few or no clonogenic progenitors in liquid cultures in the presence of cytokines. When seeded on layers derived from the murine BM stromal cell line M2-10B4, 38-86% of the cells purified using this approach generated multilineage progenitors acting as LTC-lCs. In a different series of studies, after 5-week culture on human BM stromal cell line L87/4 layers, cells were forced to selected lineage differentiation by culture in the presence of low concentrations of SF and high concentrations of lineage-specific cytokines such as Flt3-ligand (myeloid and pre-B cell differentiation), Tpo (megakaryocytic differentiation). IL-7, and IL-2 (pre-B and NK differentiation). After 12-day culture under these conditions, generation of myeloid, pre-B, megakaryocytic, and NK progenitors was assessed by immunohistochemistry, flow cytometry, and mRNA expression of CD7, 14, 19, 41b, S6, and 61. We conclude that this procedure for multilineage progenitor cell purification is simple and effective and could have major implications for gene transfer and stem cell transplantation
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Dr. Edward P. Wimberly, ITC, July 2011
No full textThis video is a conversation with Dr. Edward P. Wimberly. Dr. Wimberly talks about his book, "No Shame in Wesley's Gospel: A Twenty-First Century Pastoral Gospel". Brad Ost, AUC Woodruff Library, is the interviewer
Author Rights and Scholarly Publishing
No full textOriginally posted at
http://blog.library.gsu.edu/2014/10/24/author-rights-and-scholarly-publishing/</p
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