“A Dialogue on Market Innovation and Laissez Faire”

A dialogue on laissez faire capitalism and the free market

The Productivity of Scientific Rhetoric

We argue that the rhetoric of science occupies an important niche in contemporary science studies. Although we are pluralistic about how different rhetoricians of science can and do conduct their inquiries, we assert that their disciplinarily distinctive approach is to treat argumentation as a constituent of context. From this perspective, we observe various interacting forms of rationality at work in the controversies that constitute science in society. We argue that modes of discovery and modes of proof are mutually engaged in the process of rhetorical invention. We identify a variety of topics or commonplaces that show invention as we conceive it at work. We take a pro-science attitude toward the role of science in finding the truth and in sustaining democratic institutions

Unsupervised learning for coherent structure identification in turbulent channel flow

Coherent structures (CS), i.e., regions of flow exhibiting significant spatio-temporal coherence, have long been observed in turbulent fluid flow. These CS offer an opportunity to gain insights on fluid behaviour by bypassing the non-linear complexities associated with turbulent flows. Historically, the identification of CS in turbulent flows has involved using manual thresholds to label regions of interest. More recently, work towards more objective threshold selection have used percolation analysis; yet, particular situations can leave the method vulnerable to human bias. This work takes further steps towards pruning human subjectivity from the CS detection process, where an unsupervised learning framework that uses a clustered self-organizing map is used to automatically organize salient regions of flow within a turbulent channel into distinct clusters. The CS identified and analyzed throughout the study include quasi-streamwise coherent vortices, ejections, and sweeps. Structures pertaining to the near-wall region (+⪅60), inner region (+⪅100), and entire wall-normal domain are investigated. Structures are found to agree qualitatively with dynamic expectations, i.e., near-wall vortex structures are quasi-streamwise, and ejection and sweep regions flank vortices. Quadrant distributions of the ejection and sweep structures show larger sweep strength in the lower buffer region (+⪅15) and larger ejection strength above the buffer region (+⪆15), both characterized by large fluctuating streamwise velocity, whereas streamwise and wall-normal fluctuations in ejections and sweeps that populate the outer layer are more balanced; vorticity component distributions within vortices indicate counter streamwise rotating vortices in the buffer region; orientation statistics of vortices show preference for streamwise orientation in the near-wall, transverse orientation in the log-layer, and no preferred orientation in the outer layer; and the distribution of vorticity transport components, i.e., stretching and tilting, within vortex clusters demonstrate dominant streamwise vortex stretching within buffer layer vortices. Evidence is found of outer layer structures that resemble outsized counterparts of the ejection--vortex--sweep structures found in the near-wall, reinforcing the notion that a hiearchichal self-sustaining process exists in channel flow turbulence

Projects for regeneration: Making them work

YesThe study analyses approaches to the management of two projects within the regeneration portfolio of a large UK metropolitan council. Developing a theoretical framework drawing both from mainstream project methodologies and international development, the study highlights a number of key issues which need to be addressed, including entrepreneurship, participation, stakeholder buy-in, project lifecycles and benefit management. Key lessons emerging from the study include the need to foster entrepreneurship within the controlled environment of the project and the importance of setting programme targets which are appropriately orientated to harness the interdependent nature of benefits of regeneration projects in the public sector.Non

The effects of inorganic nitrate solutions on dormant seeds

The role of nitrate solutions in stimulating the germination of seeds in soil was investigated with a series of laboratory and field experiments. Comparisons were made between ruderal species from disturbed sites, calcicole species from calcareous grassland and calcifuge species from acidic heathland. Germination tests showed that maximum germination of four ruderal species (Artemisia vulgaris, Cardamine hirsuta, Senecio -2 -3 vulgaris and Stellaria media) occurred in 10 M to 10 M potassium nitrate. Twenty-two ruderal species were incubated on a thermobar, —2 with and without 10 M nitrate, in light and darkness in eleven temperature regimes with different diurnal temperature ranges. The greatest additional germination with nitrate in many of these species occurred at the larger diurnal temperature ranges which were already stimulatory. The calcicole and calcifuge species generally failed to respond to nitrate solutions but were stimulated by alternating temperatures. Seeds of the four ruderal species were buried outdoors for varying periods and then incubated in controlled conditions. Their response to nitrate was lost and their responses to light and alternating temperatures were reduced. Naturally buried seedbanks of soil from the three habitats, when incubated in controlled conditions, also failed to show any stimulation by nitrate. Field experiments to test the effects of added nitrate on seedling emergence from natural seedbanks were performed in 1981 and 1982. In 1981 a nitrification inhibitor was used to control natural nitrate levels in the soil but its apparent stimulation of emergence made interpretation difficult. The only significant response to nitrate was in Poa spp., with 20% higher germination in nitrate than in water treatments. In 1982 no responses to nitrate could be isolated. These results were discussed in terms of the possible role of nitrate in the detection of safe sites for germination and the adaptive nature of any response to nitrate by ruderal species

Measurement of the Parallax of PSR B0950+08 Using the VLBA

A new technique has been developed to remove the ionosphere's distorting effects from low frequency VLBI data. By fitting dispersive and non-dispersive components to the phases of multi-frequency data, the ionosphere can be effectively removed from the data without the use of {\em a priori} calibration information. This technique, along with the new gating capability of the VLBA correlator, was used to perform accurate astrometry on pulsar B0950+08, resulting in a much improved measurement of this pulsar's proper motion ($\mu_{\alpha} = -1.6 \pm 0.4$ mas/yr, $\mu_{\delta} = 29.5 \pm 0.5$ mas/yr) and parallax ($\pi = 3.6 \pm 0.3$ mas). This puts the pulsar at a distance of $280 \pm 25$ parsecs, about twice as far as previous estimates, but in good agreement with models of the electron density in the local bubble.Comment: 5 pages, Latex with AASTEX. Accepted for publication in Ap

An environmental impact study of inter-dental cleaning aids

AIM: The aim of this study was to compare the environmental footprint of eight interdental cleaning aids. MATERIALS AND METHODS: A comparative LCA was conducted based on an individual person using interdental cleaning aids every day for 5 years. The primary outcome was a life cycle impact assessment. This comprised of 16 discrete measures of environmental sustainability (known as impact categories), for example greenhouse gas emissions (measured in kg CO2e), ozone layer depletion (measured in kg CFCe), and water use (measured in m3 ). Secondary outcomes included normalised data, disability adjusted life years, and contribution analysis. RESULTS: Interdental cleaning using floss picks had the largest environmental footprint in 13 out of 16 impact categories. Depending on the environmental impact category measured, the smallest environmental footprint came from daily interdental cleaning with either bamboo interdental brushes (5 impact categories, including carbon footprint), replaceable-head interdental brushes (4 impact categories), regular floss (3 impact categories), sponge floss (3 impact categories) and bamboo floss (1 impact category). CONCLUSION: Daily cleaning with interdental cleaning aids has an environmental footprint that varies depending on the product used. Clinicians should consider environmental impact alongside clinical need and cost when recommending interdental cleaning aids to patients

Inadequacies in the conventional treatment of the radiation field of moving sources

There is a fundamental difference between the classical expression for the retarded electromagnetic potential and the corresponding retarded solution of the wave equation that governs the electromagnetic field. While the boundary contribution to the retarded solution for the {\em potential} can always be rendered equal to zero by means of a gauge transformation that preserves the Lorenz condition, the boundary contribution to the retarded solution of the wave equation governing the {\em field} may be neglected only if it diminishes with distance faster than the contribution of the source density in the far zone. In the case of a source whose distribution pattern both rotates and travels faster than light {\em in vacuo}, as realized in recent experiments, the boundary term in the retarded solution governing the field is by a factor of the order of $R^{1/2}$ {\em larger} than the source term of this solution in the limit that the distance $R$ of the boundary from the source tends to infinity. This result is consistent with the prediction of the retarded potential that part of the radiation field generated by a rotating superluminal source decays as $R^{-1/2}$, instead of $R^{-1}$, a prediction that is confirmed experimentally. More importantly, it pinpoints the reason why an argument based on a solution of the wave equation governing the field in which the boundary term is neglected (such as appears in the published literature) misses the nonspherical decay of the field