A fast MPP algorithm for Ising spin exchange simulations

A very efficient massively parallel processor (MPP) algorithm is described for performing one important class of Ising spin simulations. Results and physical significance of MPP calculations using the method described is discussed elsewhere. A few comments, however, are made on the problem under study and results so far are reported. Ted Einstein provided guidance in interpreting the initial results and in suggesting calculations to perform

Trilogy On Trade Policy: Safeguards; Mfn; Multiproduct Firms

This thesis examines the effects of the imposition of trade restriction and promotion policies in a variety of frameworks. The first chapter provides an introduction. The second chapter is theoretical in nature and uses a general equilibrium model to compare the welfare effects of global trade restrictive measures to those of selective measures applied against particular countries. It is the thesis of Chapter 2 that on the grounds of economic efficiency, there is no blanket theoretical support for the MFN application of safeguards. Whether or not a safeguard action undertaken on an MFN basis is better for the world as a whole than that undertaken on a selective basis depends on two overriding factors: the notion of equivalence between the MFN and the selective trade measures, and the distribution of the rents produced by the trade measures.;Chapter 3 tackles the MFN vs. selectivity issue in an empirical framework. Using a computable general equilibrium (CGE) model, this chapter examines the effects on world welfare of the conversion to their global counterparts of selective trade measures which were present in the United States (US) and European Community (EC) in the textiles and clothing, steel, and auto industries in 1986. The effects of the presence of labour adjustment costs on the results are also considered, but they do not appear to dominate the model. This analysis suggests that the simultaneous conversion of all existing safeguards from selective measures to their global counterparts would yield non-negative world welfare changes. However, the conversion of only some to their global counterparts, while others remain as selective measures, may produce negative welfare changes.;Chapter 4 uses a simple three-good, two-country general equilibrium framework to analyze the effects of trade policy on welfare and firm profits when multiproduct firms may be present in one or both countries. Various cases are examined in which both goods are produced by multi- or single product firms at home and/or abroad, and it can be shown that the presence of joint production can have definite effects on the trade policies advocated by home and foreign producers. In particular, domestic firms may not want tariffs on all imports when multiproduct firms are located in the foreign country

Visualization of uncertainty and analysis of geographical data

A team of five worked on this challenge to identify a possible criminal strucutre within the Flitter social network. Initially we worked on the problem individually, deliberately not sharing any data, results or conclusions. This maximised the chances of spotting any blunders, unjustified assumptions or inferences and allowed us to triangulate any common conclusions. After an agreed period we shared our results demonstrating the visualization applications we had built and the reasoning behind our conclusions. This sharing of assumptions encouraged us to incorporate uncertainty in our visualization approaches as it became clear that there was a number of possible interpretations of the rules and assumptions governing the challenge. This summary of the work emphasises one of those applications detailing the geographic analysis and uncertainty handling of the network data. ©2009 IEEE

Updating predictive accident models of modern rural single carriageway A-roads

Reliable predictive accident models (PAMs) are essential to design and maintain safe road networks and yet the models most commonly used in the UK were derived using data collected 20 to 30 years ago. Given that the national personal injury accident total fell by some 30% in the last 25 years, while road traffic increased by over 60%, significant errors in scheme appraisal and evaluation based on the models currently in use seem inevitable. In this paper the temporal transferability of PAMs for modern rural single carriageway A-roads is investigated and their predictive performance is evaluated against a recent data set. Despite the age of these models, the PAMs for predicting the total accidents provide a remarkably good fit to recent data and these are more accurate than models where accidents are disaggregated by type. The performance of the models can be improved by calibrating them against recent data

Circulation near the Newfoundland Ridge

Mesoscale eddies (25 to 150 km diameter) are observed to occur along the crest of the Newfoundland Ridge and have water properties that suggest an origin near the Tail of the Bank. The eddies appear to be important features of the circulation over the Ridge...

Unexpected Effect of Internal Degrees of Freedom on Transverse Phonons in Supercooled Liquids

We show experimentally that in a supercooled liquid composed of molecules with internal degrees of freedom the internal modes contribute to the frequency dependent shear viscosity and damping of transverse phonons, which results in an additional broadening of the transverse Brillouin lines. Earlier, only the effect of internal modes on the frequency dependent bulk viscosity and damping of longitudinal phonons was observed and explained theoretically in the limit of weak coupling of internal degrees of freedom to translational motion. A new theory is needed to describe this new effect. We also demonstrate, that the contributions of structural relaxation and internal processes to the width of the Brillouin lines can be separated by measurements under high pressure

A systematic review of adverse events arising from the use of synthetic cannabinoids and their associated treatment

Context: Synthetic cannabinoids (SCs) such as “Spice”, “K2”, etc. are widely available via the internet despite increasing legal restrictions. Currently, the prevalence of use is typically low in the general community (<1%) although it is higher among students and some niche groups subject to drug testing. Early evidence suggests that adverse outcomes associated with the use of SCs may be more prevalent and severe than those arising from cannabis consumption. Objectives: To identify systematically the scientific reports of adverse events associated with the consumption of SCs in the medical literature and poison centre data. Method: We searched online databases (Medline, PsycInfo, Embase, Google Scholar and Pubmed) and manually searched reference lists up to December 2014. To be eligible for inclusion, data had to be from hospital, emergency department, drug rehabilitation services or poison centre records of adverse events involving SCs and included both self-reported and/or analytically confirmed consumption. Results: From 256 reports, we identified 106 eligible studies including 37 conference abstracts on about 4000 cases involving at least 26 deaths. Major complications include cardiovascular events (myocardial infarction, ischemic stroke and emboli), acute kidney injury (AKI), generalized tonic-clonic seizures, psychiatric presentations (including first episode psychosis, paranoia, self-harm/suicide ideation) and hyperemesis. However, most presentations were not serious, typically involved young males with tachycardia (≈37–77%), agitation (≈16–41%) and nausea (≈13–94%) requiring only symptomatic care with a length of stay of less than 8 hours. Conclusions: SCs most frequently result in tachycardia, agitation and nausea. These symptoms typically resolve with symptomatic care, including intravenous fluids, benzodiazepines and anti-emetics, and may not require inpatient care. Severe adverse events (stroke, seizure, myocardial infarction, rhabdomyolysis, AKI, psychosis and hyperemesis) and associated deaths manifest less commonly. Precise estimates of their incidence are difficult to calculate due to the lack of widely available, rapid laboratory confirmation, the variety of SC compounds and the unknown number of exposed individuals. Long-term consequences of SCs use are currently unknown