Generation of Trophoblast Stem Cells from Rabbit Embryonic Stem Cells with BMP4

Trophoblast stem (TS) cells are ideal models to investigate trophectoderm differentiation and placental development. Herein, we describe the derivation of rabbit trophoblast stem cells from embryonic stem (ES) cells. Rabbit ES cells generated in our laboratory were induced to differentiate in the presence of BMP4 and TS-like cell colonies were isolated and expanded. These cells expressed the molecular markers of mouse TS cells, were able to invade, give rise to derivatives of TS cells, and chimerize placental tissues when injected into blastocysts. The rabbit TS-like cells maintained self-renewal in culture medium with serum but without growth factors or feeder cells, whilst their proliferation and identity were compromised by inhibitors of FGFs and TGF-β receptors. Taken together, our study demonstrated the derivation of rabbit TS cells and suggested the essential roles of FGF and TGF-β signalings in maintenance of rabbit TS cell self-renewal

PAR6, A Potential Marker for the Germ Cells Selected to Form Primordial Follicles in Mouse Ovary

Partitioning-defective proteins (PAR) are detected to express mainly in the cytoplast, and play an important role in cell polarity. However, we showed here that PAR6, one kind of PAR protein, was localized in the nuclei of mouse oocytes that formed primordial follicles during the perinatal period, suggesting a new role of PAR protein. It is the first time we found that, in mouse fetal ovaries, PAR6 appeared in somatic cell cytoplasm and fell weak when somatic cells invaded germ cell cysts at 17.5 days post coitus (dpc). Meanwhile, the expression of PAR6 was observed in cysts, and became strong in the nuclei of some germ cells at 19.5 dpc and all primordial follicular oocytes at 3 day post parturition (dpp), and then obviously declined when the primordial follicles entered the folliculogenic growth phase. During the primordial follicle pool foundation, the number of PAR6 positive germ cells remained steady and was consistent with that of formed follicles at 3 dpp. There were no TUNEL (apoptosis examination) positive germ cells stained with PAR6 at any time studied. The number of follicles significantly declined when 15.5 dpc ovaries were treated with the anti-PAR6 antibody and PAR6 RNA interference. Carbenoxolone (CBX, a known blocker of gap junctions) inhibited the expression of PAR6 in germ cells and the formation of follicles. Our results suggest that PAR6 could be used as a potential marker of germ cells for the primordial follicle formation, and the expression of PAR6 by a gap junction-dependent process may contribute to the formation of primordial follicles and the maintenance of oocytes at the diplotene stage

A modest start, but a steady rise in research use: a longitudinal study of nurses during the first five years in professional life

<p>Abstract</p> <p>Background</p> <p>Newly graduated nurses are faced with a challenging work environment that may impede their ability to provide evidence-based practice. However, little is known about the trajectory of registered nurses' use of research during the first years of professional life. Thus, the aim of the current study was to prospectively examine the extent of nurses' use of research during the first five years after undergraduate education and specifically assess changes over time.</p> <p>Method</p> <p>Survey data from a prospective cohort of 1,501 Swedish newly graduated nurses within the national LANE study (Longitudinal Analyses of Nursing Education and Entry in Worklife) were used to investigate perceived use of research over the first five years as a nurse. The dependent variables consisted of three single items assessing instrumental, conceptual, and persuasive research use, where the nurses rated their use on a five-point scale, from 'never' (1) to 'on almost every shift' (5). These data were collected annually and analyzed both descriptively and by longitudinal growth curve analysis.</p> <p>Results</p> <p>Instrumental use of research was most frequently reported, closely followed by conceptual use, with persuasive use occurring to a considerably lower extent. The development over time showed a substantial general upward trend, which was most apparent for conceptual use, increasing from a mean of 2.6 at year one to 3.6 at year five (unstandardized slope +0.25). However, the descriptive findings indicated that the increase started only after the second year. Instrumental use had a year one mean of 2.8 and a year five mean of 3.5 (unstandardized slope +0.19), and persuasive use showed a year one mean of 1.7 and a year five mean of 2.0 (unstandardized slope +0.09).</p> <p>Conclusion</p> <p>There was a clear trend of increasing research use by nurses during their first five years of practice. The level of the initial ratings also indicated the level of research use in subsequent years. However, it took more than two years of professional development before this increase 'kicked in.' These findings support previous research claiming that newly graduated nurses go through a 'transition shock,' reducing their ability to use research findings in clinical work.</p

Investigation of institutional changes in the UK housing market using structural break tests and time-varying parameter models

This paper investigates the effects of institutional changes within the UK housing market in recent decades using structural break tests and time-varying parameter models. This approach is motivated by models of institutional change drawn from the political science literature which focus on the existence of both fast-moving and slow-moving institutional changes and the interactions between them as drivers of the dynamics of asset prices. As a methodological contribution, we use several time-varying parameter models for the first time in investigations of institutional change. Our findings support the existence of both structural breaks and continuous variance in parameters. This contributes to our understanding of the housing market in two respects. Firstly, the dates of structural breaks appear to better match unexpected market shocks rather than remarkable political events, and this supports prior institutional theory. Secondly, assessment of the effect of slow-moving institutional changes shows that people’s biased expectations rather than the economic fundamentals have increasingly played an important role in driving housing prices in the short run although fundamentals continue to drive house prices to converge to their long-run equilibrium

Publisher Connection: Export-Led Growth in the UAE: Multivariate Causality Between Primary Exports, Manufactured Exports and Economic Growth

The principal question that this research addresses is the validity of the Export-Led Growth hypothesis (ELG) in the United Arab Emirates (UAE) over the period 1981–2012, focusing on the causality between primary exports, manufactured exports and economic growth. Unit root tests are applied to examine the time-series properties of the variables, while the Johansen cointegration test is performed to confirm or not the existence of a long-run relationship between the variables. Moreover, the multivariate Granger causality test and a modified version of Wald test are applied to examine the direction of the short-run and long-run causality respectively. The cointegration analysis reveals that manufactured exports contribute more to economic growth than primary exports in the long-run. In addition, this research provides evidence to support a bi-directional causality between manufactured exports and economic growth in the short-run, while the Growth-Led Exports (GLE) hypothesis is valid in the long-run for UAE