Dynamic optimal taxation with human capital.

This paper revisits the dynamic optimal taxation results of Jones, Manuelli, and Rossi (1993, 1997). They use a growth model with human capital and find that optimal taxes on both capital income and labor income converge to zero in steady state. For one of the models under consideration, I show that the representative household's problem does not have an interior solution. This raises concerns since these corners are inconsistent with aggregate data. Interiority is restored if preferences are modified so that human capital augments the value of leisure time. With this change, the optimal tax problem is analyzed and, reassuringly, the Jones, Manuelli, and Rossi results are confirmed: neither capital income nor labor income should be taxed in steady state

α_1L-adrenoceptors mediate contraction of human erectile tissue

α1-adrenoceptor antagonists can impact upon sexual function and have potential in the treatment of erectile dysfunction. Human erectile tissue contains predominantly α1A-adrenoceptors, and here we examined whether contractions of this tissue are mediated by the functional phenotype, the α1L-adrenoceptor. Functional experiments using subtype selective agonists and antagonists, along with radioligand ([3H]tamsulosin) binding assays, were used to determine the α1-adrenoceptor population. A61603, a α1A-adrenoceptor agonist, was a full agonist with a potency 21-fold greater than that of noradrenaline. The α1A- and α1D-adrenoceptor antagonist tamsulosin antagonized noradrenaline responses with high affinity (pKD = 9.7 ± 0.3), whilst BMY7378 (100 nM) (α1D-adrenoceptor antagonist) failed to antagonize responses. In contrast, relatively low affinity estimates were obtained for both prazosin (pKD = 8.2 ± 0.1) and RS17053 (pKD = 6.9 ± 0.2), antagonists which discriminate between the α1A- and α1L-adrenoceptors. [3H]Tamsulosin bound with high affinity to the receptors of human erectile tissue (pKD = 10.3 ± 0.1) with a receptor density of 28.1 ± 1.4 fmol mg−1 protein. Prazosin displacement of [3H]tamsulosin binding revealed a single homogenous population of binding sites with a relatively low affinity for prazosin (pKi = 8.9). Taken together these data confirm that the receptor mediating contraction in human erectile tissue has the pharmacological properties of the α1L-adrenoceptor. Keywords: Erectile tissue, α1-adrenoceptor subtypes, α1L-adrenoceptor, Tamsulosin, Prazosi

‘Living on the edge’: using cognitive filters to appraise experience of environmental risk

Individuals respond to an experience of risk, both in attitudinal and behavioural terms as a result of how that experience is interpreted and appraised. Experience of local flooding can in theory, inform individuals’ attitudes towards climate change. This trend however, is not observed in all cases and is highly dependent on the local, situational context. This paper postulates that the variation observed in attitudinal and behavioural responses by farmers to climate change following experiences of local flooding can, in part, be explained by the Cognitive Filters of Experience Appraisal Model introduced in this paper. The model is developed firstly through a review of the existing literature concerning appraisal (cognitive and experience). Secondly, the model is framed by empirical research via fifteen face to face interviews with farmers in Gloucestershire, England, who have all directly experienced flooding in recent years. The study is exploratory in nature, and the qualitative data serve as contextualised accounts of the different patterns of experience appraisal. The paper contributes to existing literature by developing current understandings of experience appraisal as well as providing qualitative detail to an area which has generally only been researched quantitatively. The model of experience appraisal which is put forward could be applied to multiple contexts of environmental risk

Photon echo quantum memories in inhomogeneously broadened two level atoms

Here we propose a solid-state quantum memory that does not require spectral holeburning, instead using strong rephasing pulses like traditional photon echo techniques. The memory uses external broadening fields to reduce the optical depth and so switch off the collective atom-light interaction when desired. The proposed memory should allow operation with reasonable efficiency in a much broader range of material systems, for instance Er3+ doped crystals which have a transition at 1.5 um. We present analytic theory supported by numerical calculations and initial experiments.Comment: 7 pages, 8 figure

Wave Transformation Across a Macrotidal Shore Platform Under Low to Moderate Energy Conditions

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordWe investigate how waves are transformed across a shore platform as this is a central question in rock coast geomorphology. We present results from deployment of three pressure transducers over four days, across a sloping, wide (~200 m) cliff-backed shore platform in a macrotidal setting, in South Wales, United Kingdom. Cross-shore variations in wave heights were evident under the predominantly low to moderate (significant wave height < 1.4 m) energy conditions measured. At the outer transducer 50 m from the seaward edge of the platform (163 m from the cliff) high tide water depths were 8+ m meaning that waves crossed the shore platform without breaking. At the mid-platform position water depth was 5 m. Water depth at the inner transducer (6 m from the cliff platform junction) at high tide was 1.4 m. This shallow water depth forced wave breaking, thereby limiting wave heights on the inner platform. Maximum wave height at the middle and inner transducers were 2.41 and 2.39 m, respectively, and significant wave height 1.35 m and 1.34 m, respectively. Inner platform high tide wave heights were generally larger where energy was up to 335% greater than near the seaward edge where waves were smaller. Infragravity energy was less than 13% of the total energy spectra with energy in the swell, wind and capillary frequencies accounting for 87% of the total energy. Wave transformation is thus spatially variable and is strongly modulated by platform elevation and the tidal range. While shore platforms in microtidal environments have been shown to be highly dissipative, in this macro-tidal setting up to 90% of the offshore wave energy reached the landward cliff at high tide, so that the shore platform cliff is much more reflective.W Stephenson's field work was supported by Australian Research Council grant (DP0557205). A RGS-EPSRC Small Research Grant supported L.A. Naylor

Microstability analysis of pellet fuelled discharges in MAST

Reactor grade plasmas are likely to be fuelled by pellet injection. This technique transiently perturbs the profiles, driving the density profile hollow and flattening the edge temperature profile. After the pellet perturbation, the density and temperature profiles relax towards their quasi-steady-state shape. Microinstabilities influence plasma confinement and will play a role in determining the evolution of the profiles in pellet fuelled plasmas. In this paper we present the microstability analysis of pellet fuelled H-mode MAST plasmas. Taking advantage of the unique capabilities of the MAST Thomson scattering system and the possibility of synchronizing the eight lasers with the pellet injection, we were able to measure the evolution of the post-pellet electron density and temperature profiles with high temporal and spatial resolution. These profiles, together with ion temperature profiles measured using a charge exchange diagnostic, were used to produce equilibria suitable for microstability analysis of the equilibrium changes induced by pellet injection. This analysis, carried out using the local gyrokinetic code GS2, reveals that the microstability properties are extremely sensitive to the rapid and large transient excursions of the density and temperature profiles, which also change collisionality and beta e significantly in the region most strongly affected by the pellet ablation.Comment: 21 pages, 10 figures. This is an author-created, un-copyedited version of an article submitted for publication in Plasma Physics and Controlled Fusion. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from i

Assessing Convective Heat Transfer Coefficients Associated with Indoor Shading Attachments Using a New Technique Based on Computational Fluid Dynamics

© 2015 ASHRAE (www.ashrae.org). Published in ASHRAE Conference Papers, Winter Conference, Chicago, IL. For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE's prior written permission.ASHRAE research project RP-1311 concluded with the creation of simulation models, the ASHWAT models, for glazing systems with shading attachments. Such assemblies are known as Complex Fenestration Systems (CFS). ASHWAT represents several key advances. An “equivalent layer” approach is used to track radiation at glazing layers, slat-type blinds, roller blinds, pleated drapes and insect screens. Longwave and off-normal solar optical properties are available for each of these shading layer types. A general thermal resistance framework allows for calculation of U-factor and Solar Heat Gain Coefficient (SHGC). Radiant flux, solar beam/diffuse or longwave, within the CFS multi-layer array is tracked by ASHWAT using an accounting system that is straightforward. To support this operation a large effort was devoted to the compilation of optical properties for shading layers - based on a significant level of measurement and analysis. It is also necessary to account for convective heat transfer between the various CFS layers. Methods to obtain convective heat transfer coefficients for glazing cavities are well established, even for a glazing cavity that includes a venetian blind. However, the convective heat transfer coefficients in the vicinity of a shading layer mounted next to a glazing system are not so readily obtained. Added complexity arises because each of three temperature nodes – indoor glazing surface, shading layer and room air – exchanges thermal energy with the other two nodes so three convective heat transfer coefficients are needed. No previous work provides an analysis of this three-resistor system. ASHWAT currently incorporates estimates of the three convective heat transfer coefficients, as functions of glass-to-shade spacing, based largely on known limiting cases and a limited amount of observation related to the behaviour of venetian blinds. Convective heat transfer coefficients can readily be evaluated in a two-resistor network. Quantification of the heat transfer between the nodes, for a given temperature difference, is sufficient. This is not the case for a three-node system. However, recent theoretical work shows that the three heat transfer coefficients can be obtained using a unique numerical perturbation procedure. Also, if this perturbation procedure is applied through Computational Fluid Dynamics (CFD) it is possible, using a specific sequence of steps, to escape the numerical error associated with small perturbations. The same approach cannot be applied to experimentation with natural convection. Theory is presented and sample results are compared to the ASHWAT estimates for a shading layer mounted adjacent to the indoor side of a window.Smart Net-Zero Energy Buildings Research Network (SNEBRN) || Natural Science and Engineering Research Council (NSERC) of Canada || University of Waterlo