Synthetic Mudscapes: Human Interventions in Deltaic Land Building

In order to defend infrastructure, economy, and settlement in Southeast Louisiana, we must construct new land to mitigate increasing risk. Links between urban environments and economic drivers have constrained the dynamic delta landscape for generations, now threatening to undermine the ecological fitness of the entire region. Static methods of measuring, controlling, and valuing land fail in an environment that is constantly in flux; change and indeterminacy are denied by traditional inhabitation. Multiple land building practices reintroduce deltaic fluctuation and strategic deposition of fertile material to form the foundations of a multi-layered defence strategy. Manufactured marshlands reduce exposure to storm surge further inland. Virtual monitoring and communication networks inform design decisions and land use becomes determined by its ecological health. Mudscapes at the threshold of land and water place new value on former wastelands. The social, economic, and ecological evolution of the region are defended by an expanded web of growing land

Materials Characterization Using Acoustic Nonlinearity Parameters and Harmonic Generation: Effects of Crystalline and Amorphous Structures

The importance of nonlinearity in the description of material behavior is gaining widespread attention. Nonlinearity plays a major, if not dominating, role in a number of material properties. For example, properties that are important in engineering design such as thermal expansion or the pressure dependence of optical refraction are inherently nonlinear [1]. New assembley techniques such as the use of ultrasonic gauges to determine the loading of critical fasteners depend upon nonlinear properties of the fasteners [2]. Areas of considerable fundamental interest in nonlinearity include lattice dynamics [3], radiation stress in solids [4,5], and nonlinear optics [6

Schizophrenia treatment with second-generation antipsychotics : a multi-country comparison of the costs of cardiovascular and metabolic adverse events and weight gain

Purpose: Cardiovascular and metabolic adverse events are costly to treat, and their incidence is increased amongst people with schizophrenia, with different rates observed for second-generation antipsychotics. To inform treatment choice, this study sought to estimate the lifetime costs associated with antipsychotic choice, and how these costs varied across European countries. Methods: Systematic searches were conducted to identify evidence on effectiveness and costs. A Markov model was developed to assess the costs of ten antipsychotics: aripiprazole, brexpiprazole, cariprazine, lumateperone, lurasidone, olanzapine, paliperidone, quetiapine, risperidone and ziprasidone. Costs were obtained for seven countries: Italy, Hungary, France, Slovenia, Spain, Sweden and the UK. The costs considered were adverse events (including diabetes, myocardial infarction, stroke and weight gain), drug costs, relapse, treatment discontinuation and schizophrenia management. Two adult populations were modelled; initiating either acute or maintenance treatment, with a lifetime horizon for both. Results: Lurasidone was associated with the lowest lifetime costs amongst patients initiating acute treatment compared to all other atypical antipsychotics considered. The second lowest costs were for ziprasidone. These results were observed for all seven countries. The main drivers of cost differences were rates of diabetes and cardiovascular diseases, which were lowest for lurasidone, followed by ziprasidone then lumateperone. Costs for managing weight gain were lowest for lurasidone and ziprasidone. Similar results were observed for patients initiating maintenance treatment. Conclusion: Diabetes and cardiovascular events are large drivers of lifetime costs for people with schizophrenia. Lurasidone is predicted to have the lowest rates of these adverse events, and so the lowest costs amongst patients initiating acute treatment in seven European countries compared to nine other antipsychotics. Future research should investigate the individual costs of relapse management, including differences in the costs and proportions of hospitalizations

Laboratory and field scale demonstration of reactive barrier systems

In an effort to devise a cost efficient technology for remediation of uranium contaminated groundwater, the Department of Energy`s Uranium Mill Tailings Remedial Action (DOE-UMTRA) Program through Sandia National Laboratories (SNL) fabricated a pilot scale research project utilizing reactive subsurface barriers at an UMTRA site in Durango, Colorado. A reactive subsurface barrier is produced by placing a reactant material (in this experiment, metallic iron) in the flow path of the contaminated groundwater. The reactive media then removes and/or transforms the contaminant(s) to regulatory acceptable levels. Experimental design and results are discussed with regard to other potential applications of reactive barrier remediation strategies at other sites with contaminated groundwater problems

Phonon drag thermopower and weak localization

Previous experimental work on a two-dimensional (2D) electron gas in a Si-on-sapphire device led to the conclusion that both conductivity and phonon drag thermopower $S^g$ are affected to the same relative extent by weak localization. The present paper presents further experimental and theoretical results on these transport coefficients for two very low mobility 2D electron gases in $\delta-$doped GaAs/Ga$_x$Al$_{1-x}$As quantum wells. The experiments were carried out in the temperature range 3-7K where phonon drag dominates the thermopower and, contrary to the previous work, the changes observed in the thermopower due to weak localization were found to be an order of magnitude less than those in the conductivity. A theoretical framework for phonon drag thermopower in 2D and 3D semiconductors is presented which accounts for this insensitivity of $S^g$ to weak localization. It also provides transparent physical explanations of many previous experimental and theoretical results.Comment: 19 page Revtex file, 3 Postscript figur

A NEW DEVICE AND METHOD FOR MEASURING VOLATILE COMPOUNDS IN MONITORING WELLS

Accurate, timely measurement of chlorinated solvents and other volatile contaminants in groundwater is crucial to support responsible environmental management. Traditionally, two distinctly different paradigms have been explored to meet this need--fixed laboratory analysis and ''real-time'' sensors. While these alternatives remain important, field based and field screening tools represent a potentially useful intermediate approach that balances some of the advantages and disadvantages of the traditional ''endmember'' paradigms. The value of accurate, in-field measurements during characterization was recognized in recent sampling/decision methods, such as the TRIAD approach (ITRC, 2003). Strategies that support gathering accurate data on the timescales representative of the rate of change of the system (e.g., months to years, not seconds to minutes) is key for long-term monitoring for chlorinated solvent plumes in which attenuation based remedies are being considered. A team of researchers developed a down-well sampling device that, when used in combination with field gas analysis tools, provides data in the field. The test results indicate this tool, as configured, will provide accurate measurements (as compared with laboratory methods) at concentrations in the hundreds of ppb or higher range, but require confirmatory traditional sampling with laboratory analysis at concentrations approaching 20 ppb and less. The logistics and costs of the sampling device were somewhat complex. The results of the study, while equivocal, generally suggest that future development of this type of in-field technique may be warranted

The incidence and costs of adverse events associated with antidepressants : results from a systematic review, network meta-analysis and multi-country economic model

Purpose: There is variation in the safety profile of antidepressants. Rates of adverse events along with the costs of treating them can be an important factor influencing the choice of depression treatment. This study sought to estimate the comparative safety of commonly prescribed antidepressants, and how the costs of treating these varied across European countries. Methods: A systematic literature review was conducted (in Medline, Embase, PsycINFO and CENTRAL) to identify placebo-controlled trials reporting rates of at least one type of sexual dysfunction, weight change, insomnia, anxiety, and anhedonia. Eight antidepressants were considered: duloxetine, escitalopram, fluoxetine, paroxetine, sertraline, trazodone, venlafaxine, and vortioxetine. This evidence was synthesised via Bayesian random effects network meta-analyses to provide comparative estimates of safety. A systematic search identified country-specific costs of managing depression and adverse events of antidepressants. Evidence on costs and safety was combined in an economic model to provide country-specific costs for Bulgaria, the Czech Republic, Greece, Hungary, Italy, Romania, Slovakia, Portugal, and Poland. Results: Trazodone had the lowest rates of both insomnia (odds ratio 0.66, 95% credible interval 0.31 to 1.38) and anxiety (0.13, < 0.01 to 1.80). All antidepressants were associated with increased rates of sexual dysfunction relative to placebo. Weight change was largest for fluoxetine (kg change − 1.01, − 1.40 to − 0.60) and sertraline (− 1.00, − 1.36 to − 0.65), although heterogeneity was extreme for this outcome. No evidence was identified for anhedonia. Total costs were lowest for trazodone in all nine of the countries evaluated. This was primarily due to reduced rates of treatment discontinuation. Conclusion: Trazodone generally had the best safety profile of the antidepressants evaluated. This led to healthcare costs being lowest for trazodone in all nine European countries, emphasising the importance of considering rates of adverse events when choosing a pharmacological treatment to treat symptoms of depression

Existence of radial stationary solutions for a system in combustion theory

In this paper, we construct radially symmetric solutions of a nonlinear noncooperative elliptic system derived from a model for flame balls with radiation losses. This model is based on a one step kinetic reaction and our system is obtained by approximating the standard Arrehnius law by an ignition nonlinearity, and by simplifying the term that models radiation. We prove the existence of 2 solutions using degree theory

Acoustic Energy and Momentum in a Moving Medium

By exploiting the mathematical analogy between the propagation of sound in a non-homogeneous potential flow and the propagation of a scalar field in a background gravitational field, various wave ``energy'' and wave ``momentum'' conservation laws are established in a systematic manner. In particular the acoustic energy conservation law due to Blokhintsev appears as the result of the conservation of a mixed co- and contravariant energy-momentum tensor, while the exchange of relative energy between the wave and the mean flow mediated by the radiation stress tensor, first noted by Longuet-Higgins and Stewart in the context of ocean waves, appears as the covariant conservation of the doubly contravariant form of the same energy-momentum tensor.Comment: 25 Pages, Late

Ozone depletion events observed in the high latitude surface layer during the TOPSE aircraft program

During the Tropospheric Ozone Production about the Spring Equinox (TOPSE) aircraft program, ozone depletion events (ODEs) in the high latitude surface layer were investigated using lidar and in situ instruments. Flight legs of 100 km or longer distance were flown 32 times at 30 m altitude over a variety of regions north of 58° between early February and late May 2000. ODEs were found on each flight over the Arctic Ocean but their occurrence was rare at more southern latitudes. However, large area events with depletion to over 2 km altitude in one case were found as far south as Baffin Bay and Hudson Bay and as late as 22 May. There is good evidence that these more southern events did not form in situ but were the result of export of ozone-depleted air from the surface layer of the Arctic Ocean. Surprisingly, relatively intact transport of ODEs occurred over distances of 900–2000 km and in some cases over rough terrain. Accumulation of constituents in the frozen surface over the dark winter period cannot be a strong prerequisite of ozone depletion since latitudes south of the Arctic Ocean would also experience a long dark period. Some process unique to the Arctic Ocean surface or its coastal regions remains unidentified for the release of ozone-depleting halogens. There was no correspondence between coarse surface features such as solid ice/snow, open leads, or polynyas with the occurrence of or intensity of ozone depletion over the Arctic or subarctic regions. Depletion events also occurred in the absence of long-range transport of relatively fresh “pollution” within the high latitude surface layer, at least in spring 2000. Direct measurements of halogen radicals were not made. However, the flights do provide detailed information on the vertical structure of the surface layer and, during the constant 30 m altitude legs, measurements of a variety of constituents including hydroxyl and peroxy radicals. A summary of the behavior of these constituents is made. The measurements were consistent with a source of formaldehyde from the snow/ice surface. Median NOx in the surface layer was 15 pptv or less, suggesting that surface emissions were substantially converted to reservoir constituents by 30 m altitude and that ozone production rates were small (0.15–1.5 ppbv/d) at this altitude. Peroxyacetylnitrate (PAN) was by far the major constituent of NOy in the surface layer independent of the ozone mixing ratio