294 research outputs found
Sds22 regulates aurora B activity and microtubule-kinetochore interactions at mitosis
Sds22 defines protein phosphatase 1 location and function at kinetochores and subsequent activity of aurora B in mitosis
Plus ça change...? Innovation and continuity in UK youth employment policy during the Great Recession
In response to rising youth unemployment in the context of the Great Recession, the UK introduced since 2010 numerous policy innovations in of its youth transitional labour market policy, focusing especially on Active Labour Market Policies (ALMPs) and Vocational Education and Training (VET). But is the intense reform activity indicative of a significant path-shift in policy trajectory in a direction of greater social investment, when considered against the UK’s pre-crisis institutional legacy? Focusing on key measures implemented in England between 2010 and 2015, we draw on Hall (1993) ‘degrees of change’ conceptual framework to analyse the content of recent policy innovations and assess their relative degree of continuity with the UK’s characteristic features as a ‘liberal youth transitions’ regime (Pohl and Walther, 2007). We find that despite significant changes in policy instruments’ design, the UK’s policy goals and overall youth transition model exhibit striking continuity with the pre-crisis period. In the dimension of ALMPs, we find continued emphasis on supply-side policies aimed at encouraging young people’s early labour market entry, prioritising work experience and early activation. VET shows signs of potential paradigmatic change, with numerous measures seeking to significantly transform the VET status and level of employer involvement. However, the depth of institutional change is limited, as evidence suggests continued employer resistance to stronger coordination mechanisms and a more active role as VET providers rather than consumers
The gold standard: accurate stellar and planetary parameters for eight Kepler M dwarf systems enabled by parallaxes
We report parallaxes and proper motions from the Hawaii Infrared Parallax Program for eight nearby M dwarf stars with transiting exoplanets discovered by Kepler. We combine our directly measured distances with mass-luminosity and radius–luminosity relationships to significantly improve constraints on the host stars’ properties. Our astrometry enables the identification of wide stellar companions to the planet hosts. Within our limited sample, all the multi-transiting planet hosts (three of three) appear to be single stars, while nearly all (four of five) of the systems with a single detected planet have wide stellar companions. By applying strict priors on average stellar density from our updated radius and mass in our transit fitting analysis, we measure the eccentricity probability distributions for each transiting planet. Planets in single-star systems tend to have smaller eccentricities than those in binaries, although this difference is not significant in our small sample. In the case of Kepler-42bcd, where the eccentricities are known to be ≃0, we demonstrate that such systems can serve as powerful tests of M dwarf evolutionary models by working in L⋆ − ρ⋆ space. The transit-fit density for Kepler- 42bcd is inconsistent with model predictions at 2.1σ (22%), but matches more empirical estimates at 0.2σ (2%), consistent with earlier results showing model radii of M dwarfs are underinflated. Gaia will provide high-precision parallaxes for the entire Kepler M dwarf sample, and TESS will identify more planets transiting nearby, late-type stars, enabling significant improvements in our understanding of the eccentricity distribution of small planets and the parameters of late-type dwarfs.Support for Program number HST-HF2-51364.001-A was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555.Some of the data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Support for MAST for non-HST data is provided by the NASA Office of Space Science via grant NNX09AF08G and by other grants and contracts. This paper includes data collected by the Kepler mission. Funding for the Kepler mission is provided by the NASA Science Mission directorate. The authors acknowledge the Texas Advanced Computing Center (TACC) at The University of Texas at Austin for providing HPC resources that have contributed to the research results reported within this paper. URL: http://www.tacc.utexas.edu. (HST-HF2-51364.001-A - NASA through Space Telescope Science Institute; NAS5-26555 - NASA; NNX09AF08G - NASA Office of Space Science; NASA Science Mission directorate
Quantitative analysis of chromatin compaction in living cells using FLIM-FRET
FRET analysis of cell lines expressing fluorescently tagged histones on separate nucleosomes demonstrates that variations in chromosome compaction occur during mitosis
Regulation of mesenchymal stem cell morphology using hydrogel substrates with tunable topography and photoswitchable stiffness
Cell function can be directly influenced by the mechanical and structural properties of the extracellular environment. In particular, cell morphology and phenotype can be regulated via the modulation of both the stiffness and surface topography of cell culture substrates. Previous studies have highlighted the ability to design cell culture substrates to optimise cell function. Many such examples, however, employ photo-crosslinkable polymers with a terminal stiffness or surface profile. This study presents a system of polyacrylamide hydrogels, where the surface topography can be tailored and the matrix stiffness can be altered in situ with photoirradiation. The process allows for the temporal regulation of the extracellular environment. Specifically, the surface topography can be tailored via reticulation parameters to include creased features with control over the periodicity, length and branching. The matrix stiffness can also be dynamically tuned via exposure to an appropriate dosage and wavelength of light, thus, allowing for the temporal regulation of the extracellular environment. When cultured on the surface of the hydrogels, the morphology and alignment of immortalised human mesenchymal stem cells can be directly influenced through the tailoring of surface creases, while cell size can be altered via changes in matrix stiffness. This system offers a new platform to study cellular mechanosensing and the influence of extracellular cues on cell phenotype and function
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