Populating an economic model with health state utility values: moving towards better practice

Background: When estimating health state utility values (HSUV) for multiple health conditions, the alternative models used to combine these data can produce very different values. Results generated using a baseline of perfect health are not comparable with those generated using a baseline adjusted for not having the health condition taking into account age and gender. Despite this, there is no guidance on the preferred techniques that should be used and very little research describing the effect on cost per QALY results. Methods: Using a cardiovascular disease (CVD) model and cost per QALY thresholds, we assess the consequence of using different baseline health state utility profiles (perfect health, individuals with no history of CVD, general population) in conjunction with three models (minimum, additive, multiplicative) frequently used to estimate proxy scores for multiple health conditions. Results: Assuming a baseline of perfect health ignores the natural decline in quality of life associated with co-morbidities, over-estimating the benefits of treatment to such an extent it could potentially influence a threshold policy decision. The minimum model biases results in favour of younger aged cohorts while the additive and multiplicative technique produced similar results. Although further research in additional health conditions is required to support our findings, this pilot study highlights the urgent need for analysts to conform to an agreed reference case and provides initial recommendations for better practice. We demonstrate that in CVD, if data are not available from individuals without the health condition, HSUVs from the general population provide a reasonable approximation

Adaptively truncated Hilbert space based impurity solver for dynamical mean-field theory

We present an impurity solver based on adaptively truncated Hilbert spaces. The solver is particularly suitable for dynamical mean-field theory in circumstances where quantum Monte Carlo approaches are ineffective. It exploits the sparsity structure of quantum impurity models, in which the interactions couple only a small subset of the degrees of freedom. We further introduce an adaptive truncation of the particle or hole excited spaces, which enables computations of Green functions with an accuracy needed to avoid unphysical (sign change of imaginary part) self-energies. The method is benchmarked on the one-dimensional Hubbard model.Comment: 10 pages, 7 figure

Variable energy, high flux, ground-state atomic oxygen source

A variable energy, high flux atomic oxygen source is described which is comprised of a means for producing a high density beam of molecules which will emit O(-) ions when bombarded with electrons; a means of producing a high current stream of electrons at a low energy level passing through the high density beam of molecules to produce a combined stream of electrons and O(-) ions; means for accelerating the combined stream to a desired energy level; means for producing an intense magnetic field to confine the electrons and O(-) ions; means for directing a multiple pass laser beam through the combined stream to strip off the excess electrons from a plurality of the O(-) ions to produce ground-state O atoms within the combined stream; electrostatic deflection means for deflecting the path of the O(-) ions and the electrons in the combined stream; and, means for stopping the O(-) ions and the electrons and for allowing only the ground-state O atoms to continue as the source of the atoms of interest. The method and apparatus are also adaptable for producing other ground-state atoms and/or molecules

Populating an economic model with health state utility values: moving towards better practice

Background: When estimating health state utility values (HSUV) for multiple health conditions, the alternative models used to combine these data can produce very different values. Results generated using a baseline of perfect health are not comparable with those generated using a baseline adjusted for not having the health condition taking into account age and gender. Despite this, there is no guidance on the preferred techniques that should be used and very little research describing the effect on cost per QALY results. Methods: Using a cardiovascular disease (CVD) model and cost per QALY thresholds, we assess the consequence of using different baseline health state utility profiles (perfect health, individuals with no history of CVD, general population) in conjunction with three models (minimum, additive, multiplicative) frequently used to estimate proxy scores for multiple health conditions. Results: Assuming a baseline of perfect health ignores the natural decline in quality of life associated with co-morbidities, over-estimating the benefits of treatment to such an extent it could potentially influence a threshold policy decision. The minimum model biases results in favour of younger aged cohorts while the additive and multiplicative technique produced similar results. Although further research in additional health conditions is required to support our findings, this pilot study highlights the urgent need for analysts to conform to an agreed reference case and provides initial recommendations for better practice. We demonstrate that in CVD, if data are not available from individuals without the health condition, HSUVs from the general population provide a reasonable approximation

Generation of intense negative ion beams

An electron gun is used with a mirror electrostatic field to produce zero or near zero velocity electrons by forming a turning point in their trajectories. A gas capable of attaching zero or near zero velocity is introduced at this turning point, and negative ions are produced by the attachment or dissociative attachment process. Operation may be continuous or pulsed. Ions thus formed are extracted by a simple lens system and suitable biasing of grids

Transmission of nutrient in urban environment

University of Technology Sydney. Faculty of Engineering and Information Technology.Gross pollutant traps (GPT) are installed in many urban drainage systems in Australia to control stormwater pollutants from urban catchments. Stormwater pollutants (e.g. leaf litter) are trapped in the GPT during stormwater runoff events. If these devices are not managed properly, they may lead to deterioration of receiving water quality by introducing nutrients (phosphorus and nitrogen) from the leaf litter during dry weather periods between events. This study evaluated the release of nutrients from leaf litter in a GPT system and a novel conceptual model was developed for the prediction of phosphorus at the outlet of GPT. Catchment runoff and mathematical model were used to create an integrated model able to predict the phosphorus response from a GPT. The knowledge gained in this research is expected to contribute to improve understanding the impact of GPT on downstream water bodies. Leaf litter collected from Centennial Park was found to be a significant source of nitrogen and phosphorus where the total nitrogen (TN) and total phosphorus (TP) content were 5.1 mg g¯¹ and 0.381 mg g¯¹ respectively. The releases of TN and TP from leaf litter were determined by considering a GPT environment. Initially, the phosphorus release declined exponentially with time. Consideration of the results indicated that the rate of phosphorus release was 0.0274 d¯¹ for the first 90 days and the release rate was 0.0195 d¯¹ for 180 days. Measured higher phosphorous release rate (90 days) was used to develop conceptual model. The quantity of TP loss from leaf litter was ~88% of the P in the leaf litter for the first 90 days and ~6% for the second 90 days. This suggests that the initial rapid TP release was due to higher rate of leaching of phosphorus. It was observed that the variation of phosphorus release from GPT is associated with the quantity of trapped leaf litter and inter-event dry period. The study also found that longer retention time released more phosphorus confirming the degradation of leaf litter. Results showed that the TP released from leaf litter was faster than the release of TN. About 54% of the total phosphorus was released while 20% of the total nitrogen was released within the same time frame (22 days). This suggests that nitrogen released at a slower rate. The change of pH, increase in electrical conductivity (EC) and decrease in dissolved oxygen (DO) further confirmed the decomposition of leaf matrix. As part of this study, a model of catchment runoff quantity and quality was used. This model was based on the Stormwater Management Model (SWMM) and was used to consider different factors influencing stormwater quantity and quality from the catchment. In this study, different rainfall temporal patterns were used to investigate the influence of rainfall characteristics on catchment runoff. It was found that the predicted peak flow and loss varied significantly with rainfall temporal patterns. The rainfall loss increased and the rainfall loss rate decreased with storm duration. Furthermore, it was found that the runoff volume generated by 1 year ARI was enough to replace the volume of water stored within GPT. Therefore, rainfall events with 1 year ARI and durations of 5, 10, 20, 30, 45, 60 and 120 min were considered to determine the inlet hydrograph for the GPT. Appropriate model was developed for quantification of phosphorus, in particular the TP released from leaf litter in GPT system. The SWMM model was applied to determine the catchment runoff flow in GPT which enabled estimating of phosphorus in the stormwater runoff. The catchment runoff was used as inflow to the GPT while the out flow was obtained from level pool routing of flow through the GPT. Model simulation results showed that the predicted total phosphorus load from decay of the leaf litter in the GPT was transported downstream for most storm events. This confirmed that novel conceptual model developed in this study is capable to estimate outlet phosphorus concentration of GPT for different storm events. This information may be useful to recommend catchment management approaches to improve water quality and to set management priorities and thereby enhance the design of stormwater management systems. Hence, the results of this research have shown that catchment management need to consider leaf litter as a source of phosphorus and nitrogen in assessing downstream receiving water quality

The Weirdest People in the World?

Behavioral scientists routinely publish broad claims about human psychology and behavior in the world’s top journals based on samples drawn entirely from Western, Educated, Industrialized, Rich and Democratic (WEIRD) societies. Researchers—often implicitly—assume that either there is little variation across human populations, or that these “standard subjects” are as representative of the species as any other population. Are these assumptions justified? Here, our review of the comparative database from across the behavioral sciences suggests both that there is substantial variability in experimental results across populations and that WEIRD subjects are particularly unusual compared with the rest of the species—frequent outliers. The domains reviewed include visual perception, fairness, cooperation, spatial reasoning, categorization and inferential induction, moral reasoning, reasoning styles, selfconcepts and related motivations, and the heritability of IQ. The findings suggest that members of WEIRD societies, including young children, are among the least representative populations one could find for generalizing about humans. Many of these findings involve domains that are associated with fundamental aspects of psychology, motivation, and behavior—hence, there are no obvious a priori grounds for claiming that a particular behavioral phenomenon is universal based on sampling from a single subpopulation. Overall, these empirical patterns suggests that we need to be less cavalier in addressing questions of human nature on the basis of data drawn from this particularly thin, and rather unusual, slice of humanity. We close by proposing ways to structurally re-organize the behavioral sciences to best tackle these challenges.external validity, population variability, experiments, cross-cultural research, culture, human universals, generalizability, evolutionary psychology, cultural psychology, behavioral economics

A Comprehensive Review on Food Applications of Terahertz Spectroscopy and Imaging.

Food product safety is a public health concern. Most of the food safety analytical and detection methods are expensive, labor intensive, and time consuming. A safe, rapid, reliable, and nondestructive detection method is needed to assure consumers that food products are safe to consume. Terahertz (THz) radiation, which has properties of both microwave and infrared, can penetrate and interact with many commonly used materials. Owing to the technological developments in sources and detectors, THz spectroscopic imaging has transitioned from a laboratory-scale technique into a versatile imaging tool with many practical applications. In recent years, THz imaging has been shown to have great potential as an emerging nondestructive tool for food inspection. THz spectroscopy provides qualitative and quantitative information about food samples. The main applications of THz in food industries include detection of moisture, foreign bodies, inspection, and quality control. Other applications of THz technology in the food industry include detection of harmful compounds, antibiotics, and microorganisms. THz spectroscopy is a great tool for characterization of carbohydrates, amino acids, fatty acids, and vitamins. Despite its potential applications, THz technology has some limitations, such as limited penetration, scattering effect, limited sensitivity, and low limit of detection. THz technology is still expensive, and there is no available THz database library for food compounds. The scanning speed needs to be improved in the future generations of THz systems. Although many technological aspects need to be improved, THz technology has already been established in the food industry as a powerful tool with great detection and quantification ability. This paper reviews various applications of THz spectroscopy and imaging in the food industry

Axion-photon conversion caused by dielectric interfaces: quantum field calculation

Axion-photon conversion at dielectric interfaces, immersed in a near-homogeneous magnetic field, is the basis for the dielectric haloscope method to search for axion dark matter. In analogy to transition radiation, this process is possible because the photon wave function is modified by the dielectric layers ("Garibian wave function") and is no longer an eigenstate of momentum. A conventional first-order perturbative calculation of the transition probability between a quantized axion state and these distorted photon states provides the microwave production rate. It agrees with previous results based on solving the classical Maxwell equations for the combined system of axions and electromagnetic fields. We argue that in general the average photon production rate is given by our result, independently of the detailed quantum state of the axion field. Moreover, our result provides a new perspective on axion-photon conversion in dielectric haloscopes because the rate is based on an overlap integral between unperturbed axion and photon wave functions, in analogy to the usual treatment of microwave-cavity haloscopes.Comment: 15 pages, 2 figures; v2: minor changes to match published versio

Imaginary-time matrix product state impurity solver for dynamical mean-field theory

We present a new impurity solver for dynamical mean-field theory based on imaginary-time evolution of matrix product states. This converges the self-consistency loop on the imaginary-frequency axis and obtains real-frequency information in a final real-time evolution. Relative to computations on the real-frequency axis, required bath sizes are much smaller and less entanglement is generated, so much larger systems can be studied. The power of the method is demonstrated by solutions of a three band model in the single and two-site dynamical mean-field approximation. Technical issues are discussed, including details of the method, efficiency as compared to other matrix product state based impurity solvers, bath construction and its relation to real-frequency computations and the analytic continuation problem of quantum Monte Carlo, the choice of basis in dynamical cluster approximation, and perspectives for off-diagonal hybridization functions.Comment: 8 pages + 4 pages appendix, 9 figure