12,155 research outputs found
Teamwork and organizational innovation: the moderating role of the HRM context
Evidence is accumulating on the role of teams in shaping a variety of business outcomes, but our knowledge on the effect of teamwork on organizational innovation is still evolving. This study examines whether the extent to which two staff groups are organized in teams (production staff and management/administrative staff) affects organizational innovation and whether human resource management (HRM) systems, which can be of facilitating or con- straining nature, enhance the teamwork/innovation relationships. Hypotheses were tested with lagged and longitudinal data derived from 18 to 45 organizations from the UK manufacturing sector. Results suggest that the more widespread the use of teamwork in organizations, the higher the level of organizational innovation. Furthermore, this effect depends, particularly for production teams, on the overall quality of the HRM systems that exist in their organizations. Teamwork/innovation relationships are further moderated (for management and administrative teams) by an HRM practice that provides teams with time for thoughtful reflection. Thus, HRM systems can be of more or less facilitating or constraining nature for teams in organizations
Histone crosstalk directed by H2B ubiquitination is required for chromatin boundary integrity
Genomic maps of chromatin modifications have provided evidence for the partitioning of genomes into domains of distinct chromatin states, which assist coordinated gene regulation. The maintenance of chromatin domain integrity can require the setting of boundaries. The HS4 insulator element marks the 3′ boundary of a heterochromatin region located upstream of the chicken β-globin gene cluster. Here we show that HS4 recruits the E3 ligase RNF20/BRE1A to mediate H2B mono-ubiquitination (H2Bub1) at this insulator. Knockdown experiments show that RNF20 is required for H2Bub1 and processive H3K4 methylation. Depletion of RNF20 results in a collapse of the active histone modification signature at the HS4 chromatin boundary, where H2Bub1, H3K4 methylation, and hyperacetylation of H3, H4, and H2A.Z are rapidly lost. A remarkably similar set of events occurs at the HSA/HSB regulatory elements of the FOLR1 gene, which mark the 5′ boundary of the same heterochromatin region. We find that persistent H2Bub1 at the HSA/HSB and HS4 elements is required for chromatin boundary integrity. The loss of boundary function leads to the sequential spreading of H3K9me2, H3K9me3, and H4K20me3 over the entire 50 kb FOLR1 and β-globin region and silencing of FOLR1 expression. These findings show that the HSA/HSB and HS4 boundary elements direct a cascade of active histone modifications that defend the FOLR1 and β-globin gene loci from the pervasive encroachment of an adjacent heterochromatin domain. We propose that many gene loci employ H2Bub1-dependent boundaries to prevent heterochromatin spreading
Luminosity Dependence in the Fundamental Plane Projections of Elliptical Galaxies
We analyze the fundamental plane projections of elliptical galaxies as a
function of luminosity, using a sample of approximately 80,000 galaxies drawn
from Data Release 4 (DR4) of the Sloan Digital Sky Survey (SDSS). We separate
brightest cluster galaxies (BCGs) from our main sample and reanalyze their
photometry due to a problem with the default pipeline sky subtraction for BCGs.
The observables we consider are effective radius (R_e), velocity dispersion
(sigma), dynamical mass (M_dyn ~ R_e sigma2), effective density (sigma2/R_e2),
and effective surface brightness (mu_e). With the exception of the L-M_dyn
correlation, we find evidence of variations in the slope (i.e. the power-law
index) of the fundamental plane projections with luminosity for our normal
elliptical galaxy population. In particular, the radius-luminosity and
Faber-Jackson relations are steeper at high luminosity relative to low
luminosity, and the more luminous ellipticals become progressively less dense
and have lower surface brightnesses than lower luminosity ellipticals. These
variations can be understood as arising from differing formation histories,
with more luminous galaxies having less dissipation. Data from the literature
and our reanalysis of BCGs show that BCGs have radius-luminosity and
Faber-Jackson relations steeper than the brightest non-BCG ellipticals in our
sample, consistent with significant growth of BCGs via dissipationless mergers.
The variations in slope we find in the Faber-Jackson relation of non-BCGs are
qualitatively similar to that reported in the black hole mass-velocity
dispersion (M_BH-sigma) correlation. This similarity is consistent with a
roughly constant value of M_BH/M_star over a wide range of early type galaxies,
where M_star is the stellar mass.Comment: v2: expanded analysis of BCGs; 17 pages, 9 figures; accepted in MNRA
Radio Polarisation Study of High Rotation Measure AGNs
As radio polarised emission from astrophysical objects traverse through
foreground magnetised plasma, the physical conditions along the lines of sight
are encrypted in the form of Rotation Measure (RM). We performed broadband
spectro-polarimetric observations of high Rotation Measure (|RM| >~ 300 rad
m-2) sources away from the Galactic plane (|b| > 10 deg) selected from the NVSS
RM catalogue. The main goals are to verify the NVSS RM values, which could be
susceptible to n{\pi}-ambiguity, as well as to identify the origin of the
extreme RM values. We show that 40 % of our sample suffer from n{\pi}-ambiguity
in the NVSS RM catalogue. There are also hints of RM variabilities over ~20
years epoch for most of our sources, as revealed by comparing the RM values of
the two studies in the same frequency ranges after correcting for
n{\pi}-ambiguity. At last, we demonstrate the possibility of applying
QU-fitting to study the ambient media of AGNs.Comment: 6 pages, 2 figures; Accepted by MDPI Galaxies; Conference Proceedings
for the Polarised Emission from Astrophysical Jets meeting on June 12-16
2017, Ierapetra, Greec
Improving Proficiency in Central Venous Catheter Insertion: Standardized Simulation Based Training for Internal Medicine House Staff
Objectives:
The objectives of this study are to assess residents\u27 pre-workshop ability and comfort with CVC placement, undergo a standardized online didactic and hands-on clinical training simulation workshop, and subsequently undergo a proficiency test using simulation models to assess competency. The goal of a standardized training module is to create a universal approach to CVC placement in our institution and improve comfort and technical ability of house staff. We hypothesize that this will reduce complications and improve patient care and safety.https://jdc.jefferson.edu/patientsafetyposters/1063/thumbnail.jp
Regolith production and transport at the Susquehanna Shale Hills Critical Zone Observatory, Part 2: Insights from meteoric 10Be
Regolith-mantled hillslopes are ubiquitous features of most temperate landscapes, and their morphology reflects the climatically, biologically, and tectonically mediated interplay between regolith production and downslope transport. Despite intensive research, few studies have quantified both of these mass fluxes in the same field site. Here we present an analysis of 87 meteoric 10Be measurements from regolith and bedrock within the Susquehanna Shale Hills Critical Zone Observatory (SSHO), in central Pennsylvania. Meteoric 10Be concentrations in bulk regolith samples (n=73) decrease with regolith depth. Comparison of hillslope meteoric 10Be inventories with analyses of rock chip samples (n=14) from a 24 m bedrock core confirms that >80% of the total inventory is retained in the regolith. The systematic downslope increase of meteoric 10Be inventories observed at SSHO is consistent with 10Be accumulation in slowly creeping regolith (∼ 0.2 cm yr-1). Regolith flux inferred from meteoric 10Be varies linearly with topographic gradient (determined from high-resolution light detection and ranging-based topography) along the upper portions of hillslopes at SSHO. However, regolith flux appears to depend on the product of gradient and regolith depth where regolith is thick, near the base of hillslopes. Meteoric 10Be inventories at the north and south ridgetops indicate minimum regolith residence times of 10.5 ± 3.7 and 9.1 ± 2.9 ky, respectively, similar to residence times inferred from U-series isotopes in Ma et al. (2013). The combination of our results with U-series-derived regolith production rates implies that regolith production and erosion rates are similar to within a factor of two on SSHO hillcrests. ©2013. American Geophysical Union. All Rights Reserved
Galaxy Alignments in Very X-ray Luminous Clusters at z>0.5
We present the results of a search for galaxy alignments in 12 galaxy
clusters at z>0.5, a statistically complete subset of the very X-ray luminous
clusters from the MAssive Cluster Survey (MACS). Using high-quality images
taken with the Hubble Space Telescope (HST) that render measurement errors
negligible, we find no radial galaxy alignments within 500 kpc of the cluster
centres for a sample of 545 spectroscopically confirmed cluster members. A
mild, but statistically insignificant trend favouring radial alignments is
observed within a radius of 200 kpc and traced to galaxies on the cluster red
sequence. Our results for massive clusters at z>0.5 are in stark contrast to
the findings of previous studies which find highly significant radial
alignments of galaxies in nearby clusters at z~0.1 out to at least half the
virial radius using imaging data from the SDSS. The discrepancy becomes even
more startling if radial alignment becomes more prevalent at decreasing
clustercentric distance, as suggested by both our and previous work. We
investigate and discuss potential causes for the disparity between our findings
based on HST images of clusters at z>0.5 and those obtained using groundbased
images of systems at z~0.1. We conclude that the most likely explanation is
either dramatic evolution with redshift (in the sense that radial alignments
are less pronounced in dynamically younger systems) or the presence of
systematic biases in the analysis of SDSS imaging data that cause at least
partly spurious alignment signals.Comment: 10 pages, 11 figures, and 1 table. Accepted for publication in MNRA
USF binding sequences from the HS4 insulator element impose early replication timing on a vertebrate replicator
The nuclear genomes of vertebrates show a highly organized program of DNA replication where GC-rich isochores are replicated early in S-phase, while AT-rich isochores are late replicating. GC-rich regions are gene dense and are enriched for active transcription, suggesting a connection between gene regulation and replication timing. Insulator elements can organize independent domains of gene transcription and are suitable candidates for being key regulators of replication timing. We have tested the impact of inserting a strong replication origin flanked by the β-globin HS4 insulator on the replication timing of naturally late replicating regions in two different avian cell types, DT40 (lymphoid) and 6C2 (erythroid). We find that the HS4 insulator has the capacity to impose a shift to earlier replication. This shift requires the presence of HS4 on both sides of the replication origin and results in an advance of replication timing of the target locus from the second half of S-phase to the first half when a transcribed gene is positioned nearby. Moreover, we find that the USF transcription factor binding site is the key cis-element inside the HS4 insulator that controls replication timing. Taken together, our data identify a combination of cis-elements that might constitute the basic unit of multi-replicon megabase-sized early domains of DNA replication
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