505 research outputs found
Income poverty among Indigenous families with children: Estimates from the 1991 Census
This paper brings together information from the 1991 Census of Population and Housing and the 1990 Income and Housing Costs and Amenities Survey to estimate poverty rates for Indigenous families and non-Indigenous families at the time of the 1991 Census and to compare them with estimates from the 1986 Census. It also describes the factors associated with income poverty among Indigenous families.
The analysis in this paper is primarily descriptive and is limited to measuring income poverty using the Henderson poverty line. The main objectives are to produce the first estimates of income poverty using data from the 1991 Census and to update the estimates of poverty among Indigenous families with children derived from a similar exercise using data from the 1986 Census. The results confirm that, in 1991, the common perception that income poverty rates are much higher among the Indigenous population than among the non-Indigenous population, although the gap is less dramatic for sole parent families than it is for two-parent families, is correct. The major factor associated with this poverty is joblessness, with over half of all Indigenous families with children having no employed adults. However, poverty is still higher among those Indigenous families with children in which there is at least one employed adult than it is among comparable non-Indigenous families with children
Processing second-order stochastic dominance models using cutting-plane representations
This is the post-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2011 Springer-VerlagSecond-order stochastic dominance (SSD) is widely recognised as an important decision criterion in portfolio selection. Unfortunately, stochastic dominance models are known to be very demanding from a computational point of view. In this paper we consider two classes of models which use SSD as a choice criterion. The first, proposed by Dentcheva and Ruszczyński (J Bank Finance 30:433–451, 2006), uses a SSD constraint, which can be expressed as integrated chance constraints (ICCs). The second, proposed by Roman et al. (Math Program, Ser B 108:541–569, 2006) uses SSD through a multi-objective formulation with CVaR objectives. Cutting plane representations and algorithms were proposed by Klein Haneveld and Van der Vlerk (Comput Manage Sci 3:245–269, 2006) for ICCs, and by Künzi-Bay and Mayer (Comput Manage Sci 3:3–27, 2006) for CVaR minimization. These concepts are taken into consideration to propose representations and solution methods for the above class of SSD based models. We describe a cutting plane based solution algorithm and outline implementation details. A computational study is presented, which demonstrates the effectiveness and the scale-up properties of the solution algorithm, as applied to the SSD model of Roman et al. (Math Program, Ser B 108:541–569, 2006).This study was funded by OTKA, Hungarian
National Fund for Scientific Research, project 47340; by Mobile Innovation Centre, Budapest University of Technology, project 2.2; Optirisk Systems, Uxbridge, UK and by BRIEF (Brunel University Research Innovation and Enterprise Fund)
Airborne Laser Scanning Quantification of Disturbances from Hurricanes and Lightning Strikes to Mangrove Forests in Everglades National Park, USA
Airborne light detection and ranging (LIDAR) measurements derived before and after Hurricanes Katrina and Wilma (2005) were used to quantify the impact of hurricanes and lightning strikes on the mangrove forest at two sites in Everglades National Park (ENP). Analysis of LIDAR measurements covering 61 and 68 ha areas of mangrove forest at the Shark River and Broad River sites showed that the proportion of high tree canopy detected by the LIDAR after the 2005 hurricane season decreased significantly due to defoliation and breakage of branches and trunks, while the proportion of low canopy and the ground increased drastically. Tall mangrove forests distant from tidal creeks suffered more damage than lower mangrove forests adjacent to the tidal creeks. The hurricanes created numerous canopy gaps, and the number of gaps per square kilometer increased from about 400~500 to 4000 after Katrina and Wilma. The total area of gaps in the forest increased from about 1~2% of the total forest area to 12%. The relative contribution of hurricanes to mangrove forest disturbance in ENP is at least 2 times more than that from lightning strikes. However, hurricanes and lightning strikes disturb the mangrove forest in a related way. Most seedlings in lightning gaps survived the hurricane impact due to the protection of trees surrounding the gaps, and therefore provide an important resource for forest recovery after the hurricane. This research demonstrated that LIDAR is an effective remote sensing tool to quantify the effects of disturbances such as hurricanes and lightning strikes in the mangrove forest
Decellularization reduces the immune response to aortic valve allografts in the rat
ObjectivesCryopreserved valve allografts used in congenital cardiac surgery are associated with a significant cellular and humoral immune response. This might be reduced by removal of antigenic cellular elements (decellularization). The aim of this study was to determine the immunologic effect of decellularization in a rat allograft valve model.MethodsBrown Norway and Lewis rat aortic valves were decellularized with a series of hypotonic and hypertonic buffers, protease inhibitors, gentle detergents (Triton X-100), and phosphate-buffered saline. Valves were implanted into Lewis rats in syngeneic and allogeneic combinations. Cellular (CD3 and CD8) infiltrates were assessed with morphometric analysis, and the humoral response was assessed with flow cytometry.ResultsMorphometric analysis identified a significant reduction in CD3+ cell infiltrates (cells per square millimeter of leaflet tissue) in decellularized allografts compared with that seen in nondecellularized allografts at 1 (79 ± 29 vs 3310 ± 223, P < .001), 2 (26 ± 11 vs 109 ± 20, P = .004), and 4 weeks (283 ± 122 vs 984 ± 145, P < .001). Anti-CD8 staining confirmed the majority of infiltrates were cytotoxic T cells. Flow cytometric mean channel fluorescence intensity identified a negative shift (abrogated antibody formation) for decellularized allografts compared with nondecellularized allografts at 2 (19 ± 1 vs 27 ± 3, P = .033), 4 (35 ± 2 vs 133 ± 29, P = .001), and 16 weeks (28 ± 2 vs 166 ± 54, P = .017).ConclusionsDecellularization significantly reduces the cellular and humoral immune response to allograft tissue. This could prolong the durability of valve allografts and might prevent immunologic sensitization of allograft recipients
Numerical simulations for performance optimization of a few-cycle terawatt NOPCPA system
We present a systematic numerical design and performance study of an ultra-broadband noncollinear optical parametric chirped pulse amplification (NOPCPA) system. Using a split-step Fourier approach, we model a three-stage amplifier system which is designed for the generation of 7 fs pulses with multi-terawatt peak intensity. The numerical results are compared with recent experimental data. Several important aspects and design parameters specific to NOPCPA are identified, and the values of these parameters required to achieve optimal working conditions are investigated. We identify and analyze wavelength-dependent gain saturation effects, which are specific to NOPCPA and have a strong influence on the parametric amplification process. © Springer-Verlag 2007
The role of groups as local context in large Enterprise Social Networks: A Case Study of Yammer at Deloitte Australia
Enterprise Social Networking, the application of popular social networking techniques to the workplaces of organisations, is an increasingly common phenomenon. But its nature, benefits and proliferation are not yet fully understood. In this study we investigate ESN communication at the micro-level. We focus on the role of the group feature in structuring and providing context for communication in large ESNs. Our case study is Yammer at Deloitte. In contrast to previous studies we carry out an analysis of communication at the thread (conversation) level, rather than at the level of single messages. This allows us to provide a more contextual understanding of the group aspects of communication. We find that information sharing underpins the majority of communication threads, which speaks to the usefulness of ESN, in particular in the context of knowledge-intensive work. We further uncover differences between network-wide and group-centred communication and derive a framework of four group archetypes, based on different group communication patterns. Our findings are useful for decision-makers in providing a better understanding of the role of groups in providing local contexts for users in large ESNs
Effect of different standing poses on whole body volume acquisition by three-dimensional photonic scanning
The present study compared whole body volumes obtained by three-dimensional (3D) photonic scanning of two different poses and discussed its effect on body composition estimation. Pose A with large angles of shoulder abduction and feet separated and Pose B with shoulders abducted slightly, the elbows extended and heels together. 16 male and 13 female participants were scanned twice in each pose using a 3D scanner. The mean of whole body volume and the mean of body composition obtained with Pose B was corrected by a regression equation and compared with the results obtained from Pose A. After correction, the whole body volumes acquired with these two poses were similar [limit of agreement = (-0.71 l,0.71 l)] but the body compositions obtained with Pose A and Pose B were different [limit of agreement = (-4.4%, 4.4%)]. The results indicated that scanning using either pose gives reliable estimations for whole body volume and body composition. The whole body volume obtained from different poses can be adjusted using the regression equation but small volumetric differences translate into much more substantial differences in body fat percentage. Hence, it is recommended to use the same scanning pose consistently when monitoring individuals longitudinally
Let's Make Love: Whiteness, Cleanliness and Sexuality in the French Reception of Marilyn Monroe
Copyright © by SAGE PublicationsRichard Dyer’s seminal work on whiteness in film considers Marilyn Monroe as the epitome of an institutionally racist Hollywood system that imagines the most desirable woman to be blonde, given that blondeness is understood as a guarantee of whiteness. This article adds to other recent scholarship on Monroe that has sought to complicate this reading by examining other meanings that can be attributed to her bleached blonde hair. By closely analyzing media texts that discussed Monroe in 1950s France, this article demonstrates the way in which her performance of ideal American female sexuality was read through the prism of Monroe as icon of cleanliness and (linked) modernity. It examines the way in which Monroe’s modernity allowed her to partially escape the traditional feminine private sphere and it concludes that Monroe’s bleached blonde hair can be seen in this context as having liberatory potential
Occlusion and Motion Reasoning for Long-Term Tracking
International audienceObject tracking is a reoccurring problem in computer vision. Tracking-by-detection approaches, in particular Struck (Hare et al., 2011), have shown to be competitive in recent evaluations. However, such approaches fail in the presence of long-term occlusions as well as severe viewpoint changes of the object. In this paper we propose a principled way to combine occlusion and motion reasoning with a tracking-by-detection approach. Occlusion and motion reasoning is based on state-of-the-art long-term trajectories which are labeled as object or background tracks with an energy-based formulation. The overlap between labeled tracks and detected regions allows to identify occlusions. The motion changes of the object between consecutive frames can be estimated robustly from the geometric relation between object trajectories. If this geometric change is significant, an additional detector is trained. Experimental results show that our tracker obtains state-of-the-art results and handles occlusion and viewpoints changes better than competing tracking methods
Theory and simulation of quantum photovoltaic devices based on the non-equilibrium Green's function formalism
This article reviews the application of the non-equilibrium Green's function
formalism to the simulation of novel photovoltaic devices utilizing quantum
confinement effects in low dimensional absorber structures. It covers
well-known aspects of the fundamental NEGF theory for a system of interacting
electrons, photons and phonons with relevance for the simulation of
optoelectronic devices and introduces at the same time new approaches to the
theoretical description of the elementary processes of photovoltaic device
operation, such as photogeneration via coherent excitonic absorption,
phonon-mediated indirect optical transitions or non-radiative recombination via
defect states. While the description of the theoretical framework is kept as
general as possible, two specific prototypical quantum photovoltaic devices, a
single quantum well photodiode and a silicon-oxide based superlattice absorber,
are used to illustrated the kind of unique insight that numerical simulations
based on the theory are able to provide.Comment: 20 pages, 10 figures; invited review pape
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