2,193 research outputs found
The construction of knowledge-based economies versus knowledge societies: The cases of Germany and Singapore
In the past decades, terms such as knowledge-based economy (KBE)\u27, and \u27information/knowledge society\u27 have been adopted by governments worldwide in order to underline their interest in developing their economies and societies further and assure future growth. Many governments used these catchwords as labels for government programs and action plans aiming at economic and social prosperity. This aim of national governments to construct knowledge-based economies, information/knowledge societies, the actions taken and especially the ability or disability to do so, is the topic of this paper. As two cases of comparison act Singapore and Germany. (DIPF/Orig.
Single Nucleotide Polymorphism discovery and genotyping within the chicken Tapasin gene
Tapasin is one of the specific accessory molecules for the assembly of MHC class I molecules inside the Endoplasmic Reticulum (ER) (Antoniou et al., 2003). Mammalian tapasin is a 48 kDa transmembrane chaperone-protein (Sadasivan et al., 1996), and is member of the immunoglobulin superfamily (Ortmann et al., 1997)
Fractal-like structures in colloid science
The present work aims at reviewing our current understanding of fractal structures in the frame of colloid aggregation as well as the possibility they offer to produce novel structured materials. In particular, the existing techniques to measure and compute the fractal dimension df are critically discussed based on the cases of organic/inorganic particles and proteins. Then the aggregation conditions affecting df are thoroughly analyzed, pointing out the most recent literature findings and the limitations of our current understanding. Finally, the importance of the fractal dimension in applications is discussed along with possible directions for the production of new structured materials
single nucleotide polymorphism discovery in the avian tapasin gene
Abstract Tapasin is a transmembrane glycoprotein located in the endoplasmic reticulum. Its function is to assist the assembly of major histocompatibility complex class I molecules. The chicken Tapasin gene includes 8 exons and is localized inside the major histocompatibility complex between the 2 class IIβ genes. The aim of the current study was the estimation of single nucleotide polymorphism frequency within the avian Tapasin gene. The Tapasin gene sequence from exon 5 to exon 6 was amplified for the chicken, turkey, and pheasant, and sequences of different lengths were obtained. The sequence analysis based on PolyBayes identified 25 putative single nucleotide polymorphism sites when the 3 species were compared. The coding sequences were further translated and analyzed to identify amino acid substitutions. The results indicated that polymorphisms within this region of the gene was mainly observed in the heterozygous state. The level of conservation of the Tapasin gene sequence among species is likely to be related to the functional importance of the gene
Molecular characterization of genes involved in chicken MHC class I antigen presentation pathway
Tapasin, TAP1 and TAP2 are involved in the assembly of MHC class I molecules. The genes encoding these three products belong to the Major Histocompatibility Complex: in chicken, Tapasin is located between the two class IIb genes, while TAP1 and TAP2 are found between the two class I genes. The current study aimed at the molecular characterization of these three genes. Starting from Single Nucleotide Polymorphisms (11 in Tapasin, 18 in TAP1 and 21 in TAP2) previously discovered by the authors within these genes, the nucleotide diversity was assessed at each locus. Moreover, the haplotypes were reconstructed for each individual and the genetic distances between the chicken lines and breeds were estimated. From the analysis of the nucleotide diversity values, variable polymorphism rates could be observed among the three genes. In the three analyzed loci the SNPs rates were higher than the reported chicken genome mean nucleotide diversity of 5 SNPs kb-1. The calculation of the genetic distances permitted, generally, the distinction of animals among the analyzed lines/breeds
GoSh: a goat and sheep ESTs database.
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Amniotic microvesicles impact hatching and pregnancy percentages of in vitro bovine embryos and blastocyst microRNA expression versus in vivo controls
Embryo development and implantation are dynamic processes, responsive to external signals, and can potentially be influenced by many environmental factors. The aims of this study were to evaluate the effects of a culture medium supplemented with amniotic-derived microvesicles (MVs) on in vitro embryo hatching after cryopreservation, and pregnancy rate following embryo transfer. In addition, miRNA profiling of blastocysts produced in vitro, with or without (control; CTR) amniotic MV supplementation, was also evaluated using blastocysts produced in vivo. In vitro embryos were cultured with and without amniotic MV supplementation. In vivo blastocysts were obtained from superovulated cows. Samples for RNA isolation were obtained from three pools of 10 embryos each (in vivo, in vitro-CTR and in vitro + MVs). Our results show that the hatching percentage of cryopreserved in vitro + MVs embryos is higher (P < 0.05) than in vitro-CTR embryos and the pregnancy rate with fresh and cryopreserved in vitro + MVs embryos is higher than in vitro-CTR embryos. In addition, the analysis of differently expressed (DE) microRNAs showed that embryos produced in vivo are clearly different from those produced in vitro. Moreover, in vitro-CTR and in vitro + MVs embryos differ significantly for expression of two miRNAs that were found in higher concentrations in in vitro-CTR embryos. Interestingly, these two miRNAs were also reported in degenerated bovine embryos compared to good quality blastocysts. In conclusion, MV addition during in vitro production of embryos seems to counteract the adverse effect of in vitro culture and partially modulate the expression of specific miRNAs involved in successful embryo implantation
Cellular kinetics of perivascular MSC precursors
Mesenchymal stem/stromal cells (MSCs) and MSC-like multipotent stem/progenitor cells have been widely investigated for regenerative medicine and deemed promising in clinical applications. In order to further improve MSC-based stem cell therapeutics, it is important to understand the cellular kinetics and functional roles of MSCs in the dynamic regenerative processes. However, due to the heterogeneous nature of typical MSC cultures, their native identity and anatomical localization in the body have remained unclear, making it difficult to decipher the existence of distinct cell subsets within the MSC entity. Recent studies have shown that several blood-vessel-derived precursor cell populations, purified by flow cytometry from multiple human organs, give rise to bona fide MSCs, suggesting that the vasculature serves as a systemic reservoir of MSC-like stem/progenitor cells. Using individually purified MSC-like precursor cell subsets, we and other researchers have been able to investigate the differential phenotypes and regenerative capacities of these contributing cellular constituents in the MSC pool. In this review, we will discuss the identification and characterization of perivascular MSC precursors, including pericytes and adventitial cells, and focus on their cellular kinetics: cell adhesion, migration, engraftment, homing, and intercellular cross-talk during tissue repair and regeneration. © 2013 William C. W. Chen et al
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