17,227 research outputs found
Ethical Leadership and Ethical Voice: The Mediating Mechanisms of Value Internalization and Integrity Identity
Drawing upon self-concept and social-information processing perspectives, we theorize and test a model linking ethical leadership with ethical voice via ethical value internalization and integrity identity. In two field studies (N = 972 and N = 765, respectively) of police officers and staff in the United Kingdom and an online 3-wave study (N = 448), we investigate the mediating role of ethical value internalization and integrity identity in the relationship between ethical leadership and ethical voice. Study 1 uses time-lagged data and demonstrates ethical leadership to be positively related to followers’ ethical value internalization, which in turn enhances their integrity identity and ethical voice. The serial mediation effect of the relationship between ethical leadership and ethical voice via employees’ ethical value internalization and integrity identity is also significant. Further support for our hypotheses is provided using multi-source data (Study 2) and a 3-wave cross-lagged design (Study 3). Theoretical and practical implications are discussed
Seabed corrugations beneath an Antarctic ice shelf revealed by autonomous underwater vehicle survey: Origin and implications for the history of Pine Island Glacier
Ice shelves are critical features in the debate about West Antarctic ice sheet change and sea level rise, both because they limit ice discharge and because they are sensitive to change in the surrounding ocean. The Pine Island Glacier ice shelf has been thinning rapidly since at least the early 1990s, which has caused its trunk to accelerate and retreat. Although the ice shelf front has remained stable for the past six decades, past periods of ice shelf collapse have been inferred from relict seabed "corrugations" (corrugated ridges), preserved 340 km from the glacier in Pine Island Trough. Here we present high-resolution bathymetry gathered by an autonomous underwater vehicle operating beneath an Antarctic ice shelf, which provides evidence of long-term change in Pine Island Glacier. Corrugations and ploughmarks on a sub-ice shelf ridge that was a former grounding line closely resemble those observed offshore, interpreted previously as the result of iceberg grounding. The same interpretation here would indicate a significantly reduced ice shelf extent within the last 11 kyr, implying Holocene glacier retreat beyond present limits, or a past tidewater glacier regime different from today. The alternative, that corrugations were not formed in open water, would question ice shelf collapse events interpreted from the geological record, revealing detail of another bed-shaping process occurring at glacier margins. We assess hypotheses for corrugation formation and suggest periodic grounding of ice shelf keels during glacier unpinning as a viable origin. This interpretation requires neither loss of the ice shelf nor glacier retreat and is consistent with a "stable" grounding-line configuration throughout the Holocene
Finite Size Effect on Correlation Functions of a Bose Gas in a Trap and Destruction of the Order Parameter by Phase Fluctuations
The influence of the finite sizes on the coherent properties of 3D Bose
systems is considered. As is shown, the correlation functions of a Bose gas in
a trap have essential differences from analogous correlation functions in an
infinite system. Thus, the anomalous correlation function vanishes due to the
divergency of phase fluctuations which destruct the order parameter too. The
normal correlation function decays exponentially in time for sufficiently large
time interval.Comment: 10 pages, RevTex4, some references have been added some changes in
text are mad
Aircraft and avionic related research required to develop an effective high-speed runway exit system
Research was conducted to increase airport capacity by studying the feasibility of the longitudinal separation between aircraft sequences on final approach. The multidisciplinary factors which include the utility of high speed exits for efficient runway operations were described along with recommendations and highlights of these studies
Postprandial 25-hydroxyvitamin D response varies according to the lipid composition of a vitamin D3 fortified dairy drink
In-vitro evidence suggests that the lipid component of foods alters vitamin D absorption. This single-blinded, cross-over postprandial study examined the effect of changing the lipid component of a 20 µg vitamin D3 fortified dairy drink on postprandial 25(OH)D concentrations. Participants consumed one dairy drink per visit: a non-lipid, a pre-formed oleic acid micelle, an olive oil and a fish oil dairy drink. There was a significant time*drink*baseline status effect on 25(OH)D concentrations (p = 0.039). There were no time*drink, time or drink effects on 25(OH)D in vitamin D sufficient participants (\u3e50nmol/L). However, there was an effect of time on changes in 25(OH)D concentrations after the olive oil dairy drink (p = 0.034) in vitamin D insufficient participants (\u3c50nmol/L). There were no effects after the other diary drinks. Olive oil may improve vitamin D absorption from fortified foods. Further research is needed to examine the practical implications of changing the lipid component of fortified foods
Serum 25-Hydroxyvitamin D Response to Vitamin D Supplementation Using Different Lipid Delivery Systems in Middle-Aged and Older Adults: A Randomised Controlled Trial
Food fortification improves vitamin D intakes but is not yet mandated in many countries. Combining vitamin D with different dietary lipids altered vitamin D absorption in in vitro and postprandial studies. This randomised, placebo-controlled trial examined the effect of the lipid composition of a vitamin D-fortified dairy drink on change in 25-hydroxyvitamin D (25(OH)D) concentrations. Sixty-three healthy adults aged 50+ years were randomised to one of the following for 4 weeks: vitamin D-fortified olive oil dairy drink, vitamin D-fortified coconut oil dairy drink, vitamin D supplement or placebo control dairy drink. All vitamin D groups received 20 µg of vitamin D3 daily. Serum was collected at baseline and post-intervention to measure 25(OH)D concentrations and biomarkers of metabolic health. Repeated-measures general linear model ANCOVA (RM GLM ANCOVA) compared changes over time. There was a significant time × treatment interaction effect on 25(OH)D concentrations for those classified as vitamin D-insufficient (P \u3c 0·001) and -sufficient at baseline (P = 0·004). 25(OH)D concentrations increased significantly for all insufficient participants receiving vitamin D3 in any form. However, for vitamin D-sufficient participants at baseline, 25(OH)D concentrations only increased significantly with the coconut oil dairy drink and supplement. There was no effect of vitamin D on biomarkers of metabolic health. Vitamin D fortification of lipid-containing foods may be used in lieu of supplementation when supplement adherence is low or for individuals with dysphagia. These results are important given the recent recommendation to increase vitamin D intakes to 15–20 µg for older adults in Ireland
Gravity in the 3+1-Split Formalism II: Self-Duality and the Emergence of the Gravitational Chern-Simons in the Boundary
We study self-duality in the context of the 3+1-split formalism of gravity
with non-zero cosmological constant. Lorentzian self-dual configurations are
conformally flat spacetimes and have boundary data determined by classical
solutions of the three-dimensional gravitational Chern-Simons. For Euclidean
self-dual configurations, the relationship between their boundary initial
positions and initial velocity is also determined by the three-dimensional
gravitational Chern-Simons. Our results imply that bulk self-dual
configurations are holographically described by the gravitational Chern-Simons
theory which can either viewed as a boundary generating functional or as a
boundary effective action.Comment: 25 pages; v2: minor improvements, references adde
Extraction of Airways with Probabilistic State-space Models and Bayesian Smoothing
Segmenting tree structures is common in several image processing
applications. In medical image analysis, reliable segmentations of airways,
vessels, neurons and other tree structures can enable important clinical
applications. We present a framework for tracking tree structures comprising of
elongated branches using probabilistic state-space models and Bayesian
smoothing. Unlike most existing methods that proceed with sequential tracking
of branches, we present an exploratory method, that is less sensitive to local
anomalies in the data due to acquisition noise and/or interfering structures.
The evolution of individual branches is modelled using a process model and the
observed data is incorporated into the update step of the Bayesian smoother
using a measurement model that is based on a multi-scale blob detector.
Bayesian smoothing is performed using the RTS (Rauch-Tung-Striebel) smoother,
which provides Gaussian density estimates of branch states at each tracking
step. We select likely branch seed points automatically based on the response
of the blob detection and track from all such seed points using the RTS
smoother. We use covariance of the marginal posterior density estimated for
each branch to discriminate false positive and true positive branches. The
method is evaluated on 3D chest CT scans to track airways. We show that the
presented method results in additional branches compared to a baseline method
based on region growing on probability images.Comment: 10 pages. Pre-print of the paper accepted at Workshop on Graphs in
Biomedical Image Analysis. MICCAI 2017. Quebec Cit
Fluctuation-Response Relations for Multi-Time Correlations
We show that time-correlation functions of arbitrary order for any random
variable in a statistical dynamical system can be calculated as higher-order
response functions of the mean history of the variable. The response is to a
``control term'' added as a modification to the master equation for statistical
distributions. The proof of the relations is based upon a variational
characterization of the generating functional of the time-correlations. The
same fluctuation-response relations are preserved within moment-closures for
the statistical dynamical system, when these are constructed via the
variational Rayleigh-Ritz procedure. For the 2-time correlations of the
moment-variables themselves, the fluctuation-response relation is equivalent to
an ``Onsager regression hypothesis'' for the small fluctuations. For
correlations of higher-order, there is a new effect in addition to such linear
propagation of fluctuations present instantaneously: the dynamical generation
of correlations by nonlinear interaction of fluctuations. In general, we
discuss some physical and mathematical aspects of the {\it Ans\"{a}tze}
required for an accurate calculation of the time correlations. We also comment
briefly upon the computational use of these relations, which is well-suited for
automatic differentiation tools. An example will be given of a simple closure
for turbulent energy decay, which illustrates the numerical application of the
relations.Comment: 28 pages, 1 figure, submitted to Phys. Rev.
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