851 research outputs found
Ethnic minority immigrants and their children in Britain
According to the 2001 UK Census ethnic minority groups account for 4.6 million or
7.9 percent of the total UK population. The 2001 British Labour Force Survey
indicates that the descendants of Britain’s ethnic minority immigrants form an
important part of the British population (2.8 percent) and of the labour force (2.1
percent). In this paper, we use data from the British Labour Force Survey over the
period 1979-2005 to investigate educational attainment and economic behaviour of
ethnic minority immigrants and their children in Britain. We compare different ethnic
minority groups born in Britain to their parent’s generation and to equivalent groups
of white native born individuals. Intergenerational comparisons suggest that British
born ethnic minorities are on average more educated than their parents as well
more educated than their white native born peers. Despite their strong educational
achievements, we find that ethnic minority immigrants and their British born children
exhibit lower employment probabilities than their white native born peers. However,
significant differences exist across immigrant/ethnic groups and genders. British
born ethnic minorities appear to have slightly higher wages than their white native
born peers. But if British born ethnic minorities were to face the white native
regional distribution and were attributed white native characteristics, their wages
would be considerably lower. The substantial employment gap between British born
ethnic minorities and white natives cannot be explained by observable differences.
We suggest some possible explanations for these gaps
Coarse Bifurcation Studies of Bubble Flow Microscopic Simulations
The parametric behavior of regular periodic arrays of rising bubbles is
investigated with the aid of 2-dimensional BGK Lattice-Boltzmann (LB)
simulators. The Recursive Projection Method is implemented and coupled to the
LB simulators, accelerating their convergence towards what we term coarse
steady states. Efficient stability/bifurcation analysis is performed by
computing the leading eigenvalues/eigenvectors of the coarse time stepper. Our
approach constitutes the basis for system-level analysis of processes modeled
through microscopic simulations.Comment: 4 pages, 3 figure
Fully Automatic 3D-TEE Segmentation for the Planning of Transcatheter Aortic Valve Implantation
A novel fully automatic framework for aortic valve (AV) trunk segmentation in three-dimensional (3-D) transesophageal echocardiography (TEE) datasets is proposed. The methodology combines a previously presented semiautomatic segmentation strategy by using shape-based B-spline Explicit Active Surfaces with two novel algorithms to automate the quantification of relevant AV measures. The first combines a fast rotation-invariant 3-D generalized Hough transform with a vessel-like dark tube detector to initialize the segmentation. After segmenting the AV wall, the second algorithm focuses on aligning this surface with the reference ones in order to estimate the short-axis (SAx) planes (at the left ventricular outflow tract, annulus, sinuses of Valsalva, and sinotubular junction) in which to perform the measurements. The framework has been tested in 20 3-D-TEE datasets with both stenotic and nonstenotic AVs. The initialization algorithm presented a median error of around 3 mm for the AV axis endpoints, with an overall feasibility of 90%. In its turn, the SAx detection algorithm showed to be highly reproducible, with indistinguishable results compared with the variability found between the experts' defined planes. Automatically extracted measures at the four levels showed a good agreement with the experts' ones, with limits of agreement similar to the interobserver variability. Moreover, a validation set of 20 additional stenotic AV datasets corroborated the method's applicability and accuracy. The proposed approach mitigates the variability associated with the manual quantification while significantly reducing the required analysis time (12 s versus 5 to 10 min), which shows its appeal for automatic dimensioning of the AV morphology in 3-D-TEE for the planning of transcatheter AV implantation.This work was supported by the project "ON.2 SR&TD Integrated Program (Norte-07-0124-FEDER-000017)" cofunded by the Programa Operacional Regional do Norte (ON.2- O Novo Norte), Quadro de Referencia Estrategico Nacional, through Fundo Europeu de Desenvolvimento Regional. The work of S. Queiros and P. Morais was supported by the FCT-Fundacao para a Ciencia e a Tecnologia and the European Social Found through the Programa Operacional Capital Humano in the scope of the Ph.D. Grants SFRH/BD/93443/2013 and SFRH/BD/95438/2013, respectively. J. L. Vilaca and J. D'hooge are joint last authors. Asterisk indicates corresponding author.info:eu-repo/semantics/publishedVersio
On interconnecting and orchestrating components in disaggregated data centers:The dReDBox project vision
Computing systems servers-low-or high-end ones have been traditionally designed and built using a main-board and its hardware components as a 'hard' monolithic building block; this formed the base unit on which the system hardware and software stack design build upon. This hard deployment and management border on compute, memory, network and storage resources is either fixed or quite limited in expandability during design time and in practice remains so throughout machine lifetime as subsystem upgrades are seldomely employed. The impact of this rigidity has well known ramifications in terms of lower system resource utilization, costly upgrade cycles and degraded energy proportionality. In the dReDBox project we take on the challenge of breaking the server boundaries through materialization of the concept of disaggregation. The basic idea of the dReDBox architecture is to use a core of high-speed, low-latency opto-electronic fabric that will bring physically distant components more closely in terms of latency and bandwidth. We envision a powerful software-defined control plane that will match the flexibility of the system to the resource needs of the applications (or VMs) running in the system. Together the hardware, interconnect, and software architectures will enable the creation of a modular, vertically-integrated system that will form a datacenter-in-a-box
Comparison of Psychological Distress between Type 2 Diabetes Patients with and without Proteinuria
We investigated the link between proteinuria and psychological distress among patients with type 2 diabetes mellitus (T2DM). A total of 130 patients with T2DM aged 69.1±10.3 years were enrolled in this cross-sectional study. Urine and blood parameters, age, height, body weight, and medications were analyzed, and each patient’s psychological distress was measured using the six-item Kessler Psychological Distress Scale (K6). We compared the K6 scores between the patients with and without proteinuria. Forty-two patients (32.3%) had proteinuria (≥±) and the level of HbA1c was 7.5±1.3%. The K6 scores of the patients with proteinuria were significantly higher than those of the patients without proteinuria even after adjusting for age and sex. The clinical impact of proteinuria rather than age, sex and HbA1c was demonstrated by a multiple regression analysis. Proteinuria was closely associated with higher psychological distress. Preventing and improving proteinuria may reduce psychological distress in patients with T2DM
Data-driven model reduction-based nonlinear MPC for large-scale distributed parameter systems
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordModel predictive control (MPC) has been effectively applied in process industries since the 1990s. Models in the form of closed equation sets are normally needed for MPC, but it is often difficult to obtain such formulations for large nonlinear systems. To extend nonlinear MPC (NMPC) application to nonlinear distributed parameter systems (DPS) with unknown dynamics, a data-driven model reduction-based approach is followed. The proper orthogonal decomposition (POD) method is first applied off-line to compute a set of basis functions. Then a series of artificial neural networks (ANNs) are trained to effectively compute POD time coefficients. NMPC, using sequential quadratic programming is then applied. The novelty of our methodology lies in the application of POD's highly efficient linear decomposition for the consequent conversion of any distributed multi-dimensional space-state model to a reduced 1-dimensional model, dependent only on time, which can be handled effectively as a black-box through ANNs. Hence we construct a paradigm, which allows the application of NMPC to complex nonlinear high-dimensional systems, even input/output systems, handled by black-box solvers, with significant computational efficiency. This paradigm combines elements of gain scheduling, NMPC, model reduction and ANN for effective control of nonlinear DPS. The stabilization/destabilization of a tubular reactor with recycle is used as an illustrative example to demonstrate the efficiency of our methodology. Case studies with inequality constraints are also presented.The authors would like to acknowledge the financial support of the EC FP6 Project: CONNECT [COOP-2006-31638] and the EC FP7 project CAFE [KBBE-212754]
Biofabrication of customized bone grafts by combination of additive manufacturing and bioreactor knowhow
This study reports on an original concept of additive manufacturing for the fabrication of
tissue engineered constructs (TEC), offering the possibility of concomitantly manufacturing a
customized scaffold and a bioreactor chamber to any size and shape. As a proof of concept
towards the development of anatomically relevant TECs, this concept was utilized for the
design and fabrication of a highly porous sheep tibia scaffold around which a bioreactor
chamber of similar shape was simultaneously built. The morphology of the bioreactor/scaffold
device was investigated by micro-computed tomography and scanning electron microscopy
confirming the porous architecture of the sheep tibiae as opposed to the non-porous nature of
the bioreactor chamber. Additionally, this study demonstrates that both the shape, as well as
the inner architecture of the device can significantly impact the perfusion of fluid within the
scaffold architecture. Indeed, fluid flow modelling revealed that this was of significant
importance for controlling the nutrition flow pattern within the scaffold and the bioreactor
chamber, avoiding the formation of stagnant flow regions detrimental for in vitro tissue
development. The bioreactor/scaffold device was dynamically seeded with human primary
osteoblasts and cultured under bi-directional perfusion for two and six weeks. Primary human
osteoblasts were observed homogenously distributed throughout the scaffold, and were viable
for the six week culture period. This work demonstrates a novel application for additive
manufacturing in the development of scaffolds and bioreactors. Given the intrinsic flexibility
of the additive manufacturing technology platform developed, more complex culture systems
can be fabricated which would contribute to the advances in customized and patient-specific
tissue engineering strategies for a wide range of applications.This work was supported by the NHMRC, the Australian Research Council and Hans Fischer Senior Fellowship, IAS-TUM. Pedro Costa acknowledges the Portuguese Foundation for Science and Technology for his PhD grant (SFRH/BD/62452/2009)
A wildland fire model with data assimilation
A wildfire model is formulated based on balance equations for energy and
fuel, where the fuel loss due to combustion corresponds to the fuel reaction
rate. The resulting coupled partial differential equations have coefficients
that can be approximated from prior measurements of wildfires. An ensemble
Kalman filter technique with regularization is then used to assimilate
temperatures measured at selected points into running wildfire simulations. The
assimilation technique is able to modify the simulations to track the
measurements correctly even if the simulations were started with an erroneous
ignition location that is quite far away from the correct one.Comment: 35 pages, 12 figures; minor revision January 2008. Original version
available from http://www-math.cudenver.edu/ccm/report
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