The Development of a Human Well-Being Index for the United States

The US Environmental Protection Agency (EPA) has developed a human well-being index (HWBI) that assesses the over-all well-being of its population at the county level. The HWBI contains eight domains representing social, economic and environmental well-being. These domains include 25 indicators comprised of 80 metrics and 22 social, economic and environmental services. The application of the HWBI has been made for the nation as a whole at the county level and two alternative applications have been made to represent key populations within the overall US population—Native Americans and children. A number of advances have been made to estimate the values of metrics for counties where no data is available and one such estimator—MERLIN—is discussed. Finally, efforts to make the index into an interactive web site are described

Ionization state, excited populations and emission of impurities in dynamic finite density plasmas: I. The generalized collisional-radiative model for light elements

The paper presents an integrated view of the population structure and its role in establishing the ionization state of light elements in dynamic, finite density, laboratory and astrophysical plasmas. There are four main issues, the generalized collisional-radiative picture for metastables in dynamic plasmas with Maxwellian free electrons and its particularizing to light elements, the methods of bundling and projection for manipulating the population equations, the systematic production/use of state selective fundamental collision data in the metastable resolved picture to all levels for collisonal-radiative modelling and the delivery of appropriate derived coefficients for experiment analysis. The ions of carbon, oxygen and neon are used in illustration. The practical implementation of the methods described here is part of the ADAS Project

Development of FRET-Based Assays in the Far-Red Using CdTe Quantum Dots

Colloidal quantum dots (QDs) are now commercially available in a biofunctionalized form, and Förster resonance energy transfer (FRET) between bioconjugated dots and fluorophores within the visible range has been observed. We are particularly interested in the far-red region, as from a biological perspective there are benefits in pushing to ∼700 nm to minimize optical absorption (ABS) within tissue and to avoid cell autofluorescence. We report on FRET between streptavidin- (STV-) conjugated CdTe quantum dots, Qdot705-STV, with biotinylated DY731-Bio fluorophores in a donor-acceptor assay. We also highlight the changes in DY731-Bio absorptivity during the streptavidin-biotin binding process which can be attributed to the structural reorientation. For fluorescence beyond 700 nm, different alloy compositions are required for the QD core and these changes directly affect the fluorescence decay dynamics producing a marked biexponential decay with a long-lifetime component in excess of 100 nanoseconds. We compare the influence of the two QD relaxation routes upon FRET dynamics in the presence of DY731-Bio

A multi-scale conjugate heat transfer modelling approach for corrugated heat exchangers

The paper compares two serrated plate-fin Heat Exchanger (HE) corrugation modelling methods using Computational Fluid Dynamics (CFD). The first method follows closely recent literature studies and models a finite length single channel of a corrugation layer inside the HE core. The second method utilises the conjugate heat transfer methodology and models a section of the HE core with both cold and hot fluid streams separated by a solid conducting wall (HE corrugation). The results of latter model are then extrapolated for the full dimensions of a HE core layer to obtain flow and heat transfer characteristics. The conjugate heat transfer analysis methodology presented is novel and eliminates the need for analytical/empirical modelling currently widely used within industry. Furthermore, it provides more detailed information about the flow and heat transfer inside the HE core enabling potential for more efficient HE designs. Predictions at the corrugation level were carried out at with mesh independence studies completed for all the computational domains. The results obtained in the HE corrugation predictions were then implemented to the multi-scale HE unit model where the flow inside the HE core was modelled using two porous media simplifications whilst the heat transfer was simplified using the effectiveness source term. The HE unit predictions were validated against industrial experimental data with good agreement found between the numerical and experimental results. All the simulations were completed using the open-source CFD package OpenFOAM

A numerical evaluation of next generation additive layer manufactured inter-layer channel heat exchanger

A Concept Heat Exchanger (HE) design manufactured using the Additive Layer Manufacturing (ALM) technique Selective Laser Melting (SLM) is proposed and numerically evaluated. It is composed of a HE corrugation which introduces inter-layer flow conduits between the parallel HE layers of the same fluid. These pathways are provided by hollow elliptical tubes which serve several functions: to disturb the flow to promote heat transfer, to provide additional heat transfer area and to minimise flow maldistribution inside the HE core. The corrugation is incorporated into a counter-flow prototype HE unit model meaning to exploit the installation volume and design freedom made possible via ALM. Three Computational Fluid Dynamics (CFD) models are utilised to evaluate the performance of the proposed HE unit. Firstly, a traditional two step HE design methodology is utilised which works by initially evaluating a fully symmetric channel of the proposed HE corrugation (termed single channel). Then the results this model are incorporated into a simplified HE unit model. The second approach evaluates the HE unit performance based on a fully detailed CFD analysis that fully resolves flow and heat transfer inside the HE core. The third modelling approach involves splitting the inter-layer HE unit model into parts, which results in HE header models and allows simplification of the HE core into a single corrugation period width HE core model (termed superchannel). The results of these models are then compared to a conventional pin–fin HE unit model, formed by blocking the elliptical inter-layer conduits. It was found that in all the HE unit models the pressure drop is similar whilst the heat transfer was enhanced by between 7% and 13% in terms of the overall ΔT by the inter-layer channels (increasing with the Reynolds number). All simulations were completed using a CFD package OpenFOAM

Experimental and numerical study of the additive layer manufactured inter-layer channel heat exchanger

In this paper the performance of a recently patented additive layer manufactured (ALM) concept inter-layer heat exchanger (HE) is evaluated experimentally and numerically. Two numerical HE models are developed using the conjugate heat transfer (CHT) methodology. The first is an idealised HE core model, consisting of a single period width HE corrugation section (termed superchannel). The second approach uses a fully detailed HE unit model which resolves the flow and heat transfer inside the complete HE unit. A close agreement was found between the HE unit simulations and the experimentally obtained results, such that the fully detailed HE model could be validated. It was also shown that, a full CHT approach is necessary to accurately evaluate complex inter-layer ALM HE core flow and heat transfer behaviour and can serve as an approach for optimising HE designs. The results also reinforce the occurrence of the inter-layer flow mixing inside the HE core of the same flow streams and allows the mass flow to redistribute inside the HE core which is impossible with the current HE generation geometries. The superchannel model results in a slight over-estimation in heat transfer ( K on average) making the simplified model acceptable as a conservative estimate. Using validated simulations a parametric study was conducted by changing the solid properties of the full CHT HE model to aluminium to investigate the effects of a significantly more conductive material. This resulted in higher heat transfer effectiveness () of the HE unit. All the simulations were carried out using CFD package OpenFOAM

Flow-Based Cytometric Analysis of Cell Cycle via Simulated Cell Populations

We present a new approach to the handling and interrogating of large flow cytometry data where cell status and function can be described, at the population level, by global descriptors such as distribution mean or co-efficient of variation experimental data. Here we link the “real” data to initialise a computer simulation of the cell cycle that mimics the evolution of individual cells within a larger population and simulates the associated changes in fluorescence intensity of functional reporters. The model is based on stochastic formulations of cell cycle progression and cell division and uses evolutionary algorithms, allied to further experimental data sets, to optimise the system variables. At the population level, the in-silico cells provide the same statistical distributions of fluorescence as their real counterparts; in addition the model maintains information at the single cell level. The cell model is demonstrated in the analysis of cell cycle perturbation in human osteosarcoma tumour cells, using the topoisomerase II inhibitor, ICRF-193. The simulation gives a continuous temporal description of the pharmacodynamics between discrete experimental analysis points with a 24 hour interval; providing quantitative assessment of inter-mitotic time variation, drug interaction time constants and sub-population fractions within normal and polyploid cell cycles. Repeated simulations indicate a model accuracy of ±5%. The development of a simulated cell model, initialized and calibrated by reference to experimental data, provides an analysis tool in which biological knowledge can be obtained directly via interrogation of the in-silico cell population. It is envisaged that this approach to the study of cell biology by simulating a virtual cell population pertinent to the data available can be applied to “generic” cell-based outputs including experimental data from imaging platforms

A transfer function approach to measuring cell inheritance

<p>Abstract</p> <p>Background</p> <p>The inheritance of cellular material between parent and daughter cells during mitosis is highly influential in defining the properties of the cell and therefore the population lineage. This is of particular relevance when studying cell population evolution to assess the impact of a disease or the perturbation due to a drug treatment. The usual technique to investigate inheritance is to use time-lapse microscopy with an appropriate biological marker, however, this is time consuming and the number of inheritance events captured are too low to be statistically meaningful.</p> <p>Results</p> <p>Here we demonstrate the use of a high throughput fluorescence measurement technique e.g. flow cytometry, to measure the fluorescence from quantum dot markers which can be used to target particular cellular sites. By relating, the fluorescence intensity measured between two time intervals to a transfer function we are able to deconvolve the inheritance of cellular material during mitosis. To demonstrate our methodology we use CdTe/ZnS quantum dots to measure the ratio of endosomes inherited by the two daughter cells during mitosis in the U2-OS, human osteoscarcoma cell line. The ratio determined is in excellent agreement with results obtained previously using a more complex and computational intensive bespoke stochastic model.</p> <p>Conclusions</p> <p>The use of a transfer function approach allows us to utilise high throughput measurement of large cell populations to derive statistically relevant measurements of the inheritance of cellular material. This approach can be used to measure the inheritance of organelles, proteins etc. and also particles introduced to cells for drug delivery.</p

Molecular Engineering of the Autographa californica Nuclear Polyhedrosis Virus Genome: Deletion Mutations Within the Polyhedrin Gene

We describe a method to introduce site-specific mutations into the genome of Autographa californica nuclear polyhedrosis virus. Specifically, the A. californica nuclear polyhedrosis virus gene for polyhedrin, the major protein that forms viral occlusions in infected cells, was mutagenized by introducing deletions into the cloned DNA fragment containing the gene. The mutagenized polyhedrin gene was transferred to the intact viral DNA by mixing fragment and viral DNAs, cotransfecting Spodoptera frugiperda cells, and screening for viral recombinants that had undergone allelic exchange. Recombinant viruses with mutant polyhedrin genes were obtained by selecting the progeny virus that did not produce viral occlusions in infected cells (occlusion-negative mutants). Analyses of occlusion-negative mutants demonstrated that the polyhedrin gene was not essential for the production of infectious virus and that deletion of certain sequences within the gene did not alter the control, or decrease the level of expression, of polyhedrin. An early viral protein of 25,000 molecular weight was apparently not essential for virus replication in vitro, as the synthesis of this protein was not detected in cells infected with a mutant virus

Lower entropy bounds and particle number fluctuations in a Fermi sea

We demonstrate, in an elementary manner, that given a partition of the single particle Hilbert space into orthogonal subspaces, a Fermi sea may be factored into pairs of entangled modes, similar to a BCS state. We derive expressions for the entropy and for the particle number fluctuations of a subspace of a fermi sea, at zero and finite temperatures, and relate these by a lower bound on the entropy. As an application we investigate analytically and numerically these quantities for electrons in the lowest Landau level of a quantum Hall sample.Comment: shorter version, typos fixe