1,721,021 research outputs found
Functional identification of bovine mammary epithelial stem/progenitor cells
No full textThe in vitro and in vivo assays have been developed to detect primitive bovine mammary cells.
The in vitro CFC assay allowed us to detect different type of progenitors as demonstrated by the
different colonies that they were able to generate when cultured in vitro.
Cells from bovine mammary tissue were able to generate organized outgrowths in a xenograft model.
Moreover progenitor cells could be detected in these outgrowths, but the frequencies of the different
type of colonies showed a marked variation when compared to the CFC assay performed on freshly
dissociated BMECs.
The systems described here provide very useful tools to improve the knowledge of the bovine
mammary tissue hierarchy and of the mechanisms and factors that drive proliferation and
differentiation. As future perspective this knowledge may then be used to develop new strategies for
increasing milk production in dairy cows by specifically targeting signaling pathways that are important
in the control of the stem/progenitor cell compartmen
Isolated ruminant mammary stem cell population and uses thereof for production of transgenic proteins in vivo
No full textThus object of the present disclosure is to provide a bovine stem cell population able to (re)generate polarized and functional structures in vitro and in vivo when transplanted in an animal model.
A further object of the present disclosure is to provide a novel approach for transgene production in milk: given the huge proliferative and morphogenic potential of stem cells, such cells represent a preferential target for in vitro manipulation. The present disclosure concerns the use of a transgenic stem cell population that upon transplantation is able to regenerate mammary structure that secretes the transgene in their lumen.
According to the present invention said objects are achieved thanks to the solution having the characteristics referred to specifically in the ensuing claims. Thus the claims form integral part of the technical teaching herein provided in relation to the present invention.
To achieve this object, the present inventors have developed an isolated ruminant mammary stem cell population able to generate polarized and functional structures of a mammary gland tissue both in vitro and in vivo.
In an embodiment of the present disclosure the isolated ruminant mammary stem cell population is able to proliferate and differentiate into luminal and myoepithelial cells, thus generating mammary alveoli, which are able to secrete milk.
In a further embodiment of the instant invention, a transgenic isolated ruminant mammary stem cell population is provided, wherein the mammary stem cells contain within their DNA a construct encoding for at least one heterologous protein, which is secreted, preferably in the lumen of the luminal cells and/or the mammary alveoli.
In a still further embodiment the construct is a vector, being this vector selected among a lentiviral vector. Preferably the vector is provided at the N-terminal with a secretion signal and/or with a conditional promoter able to control the expression of the heterologous protein in the luminal cells and thus in milk.
In a further embodiment the heterologous protein is selected among human beta-casein, k-casein, beta-lactoglobulin, alpha-lactalbumin, monoclonal antibodies, plasma proteins such as the coagulation factors Factor XII, Factor XIII, Factor IX, albumin, human alpha 1 antitrypsin.
Further embodiments of the instant disclosure concern the use of the isolated ruminant mammary stem cell population for the regeneration of a ruminant mammary gland tissue and/or for increasing milk production in a ruminant.
In a further embodiment, the present disclosure concerns the use of the transgenic isolated ruminant mammary stem cell population for the production of the heterologous protein(s) in the milk of the ruminant, wherein the transgenic mammary stem cell population is transplanted in the mammary gland tissue of the ruminant
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
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