The Exchange Rate, Productivity, and the Standard of Living

This article examines the recent proposition that the decline in Canada's standard of living relative to that of the United States is causally related to the decline in our exchange rate. The authors explore the main channels through which the exchange rate and the standard of living could be related-productivity and the terms of trade-focusing mainly on productivity. They conclude that the decline in world commodity prices and weak demand for domestic output were affecting both Canada's standard of living and the exchange rate and that the flexible exchange rate regime itself did not play an independent role.

The Public Resource Management Game

Use of public resources for private economic gain is a longstanding, contested political issue. Public resources generate benefits beyond commodity uses, including recreation, environmental and ecological conservation and preservation, and existence and aesthetic values. We analyze this problem using a dynamic resource use game. Low use fees let commodity users capture more of the marginal benefit from private use. This increases the incentive to comply with government regulations. Optimal contracts therefore include public use fees that are lower than private rates. The optimal policy also includes random monitoring to prevent strategic learning and cheating on the use agreements and to avoid wasteful efforts to disguise noncompliant behavior. An optimal policy also includes a penalty for cheating beyond terminating the use contract. This penalty must be large enough that the commodity user who would gain the most from noncompliance experiences a negative expected net return.Renewable resources, public resources policy, optimal contracts

Constraints on non-minimally coupled curved space electrodynamics from astrophysical observations

We study interactions of electro-magnetic fields with the curvature tensor of the form $\lambda R_{\mu \nu \alpha \beta}F^{\mu \nu}F^{\alpha \beta}$. Such coupling terms though are invariant under general coordinate transformation and CPT, however violate the Einstein equivalence principle. These couplings do not cause any energy dependent dispersion of photons but they exhibit birefringence. We put constraints on the coupling constant $\lambda$ using results from solar system radar ranging experiments and millisecond-pulsar observations. We find that the most stringent constraint comes from pulsar observations and is given by $\lambda < 10^{11} cm^2$ obtained from the timing of binary pulsar PSR B1534+12.Comment: 9 pages latex, accepted in CQ

INADVERTENT ESTABLISHMENT OF CONTROL BY LOCATION IN MATCHING-TO-SAMPLE TASKS IN INDIVIDUALS WITH AUTISM SPECTRUM DISORDER

Estudos com sujeitos não humanos mostraram que o estabelecimento de controle inadvertido pela localização pode prejudicar a aquisição de relações condicionais em procedimentos de matching-to-sample (MTS). O objetivo do Experimento 1 foi verificar se esse fenômeno ocorreria com indivíduos com Transtorno do Espectro Autista (TEA) em sessões de treino com MTS sem procedimentos adicionais que pudessem favorecer a aquisição, tais como procedimentos de esvanecimento, dicas e correção. Todos os três participantes mostraram controle pela localização mesmo depois de completar um mínimo de 50 sessões de treino com MTS arbitrário com dois estímulos de comparação. Um segundo estudo foi realizado para verificar se o controle pela localização ocorreria durante o procedimento MTS usando três estímulos comparação. Dezesseis participantes completaram duas sessões de treino. Os resultados deste estudo indicam que 13 desses participantes exibiram controle pela localização no início do treino. Em conjunto, os resultados de ambos os experimentos indicam que o controle pela localização pode prejudicar a aquisição de relações condicionais em indivíduos com TEA, utilizando procedimentos MTS, sem procedimentos adicionais de aprendizagem sem erro, como apresentação ou esvanecimento de dicas.Palavras-chave: controle por localização, matching-to-sample, discriminação condicional, Transtorno do Espectro Autista.Estudos com sujeitos não humanos mostraram que o estabelecimento de controle inadvertido pela localização pode prejudicar a aquisição de relações condicionais em procedimentos de matching-to-sample (MTS). O objetivo do Experimento 1 foi verificar se esse fenômeno ocorreria com indivíduos com Transtorno do Espectro Autista (TEA) em sessões de treino com MTS sem procedimentos adicionais que pudessem favorecer a aquisição, tais como procedimentos de esvanecimento, dicas e correção. Todos os três participantes mostraram controle pela localização mesmo depois de completar um mínimo de 50 sessões de treino com MTS arbitrário com dois estímulos de comparação. Um segundo estudo foi realizado para verificar se o controle pela localização ocorreria durante o procedimento MTS usando três estímulos comparação. Dezesseis participantes completaram duas sessões de treino. Os resultados deste estudo indicam que 13 desses participantes exibiram controle pela localização no início do treino. Em conjunto, os resultados de ambos os experimentos indicam que o controle pela localização pode prejudicar a aquisição de relações condicionais em indivíduos com TEA, utilizando procedimentos MTS, sem procedimentos adicionais de aprendizagem sem erro, como apresentação ou esvanecimento de dicas.Palavras-chave: controle por localização, matching-to-sample, discriminação condicional, Transtorno do Espectro Autista

Black Hole Entropy without Brick Walls

We present evidence which confirms a suggestion by Susskind and Uglum regarding black hole entropy. Using a Pauli-Villars regulator, we find that 't Hooft's approach to evaluating black hole entropy through a statistical-mechanical counting of states for a scalar field propagating outside the event horizon yields precisely the one-loop renormalization of the standard Bekenstein-Hawking formula, S=\A/(4G). Our calculation also yields a constant contribution to the black hole entropy, a contribution associated with the one-loop renormalization of higher curvature terms in the gravitational action.Comment: 15 pages, plain LaTex minor additions including some references; version accepted for publicatio

Do acute elevations of serum creatinine in primary care engender an increased mortality risk?

Background: The significant impact Acute Kidney Injury (AKI) has on patient morbidity and mortality emphasizes the need for early recognition and effective treatment. AKI presenting to or occurring during hospitalisation has been widely studied but little is known about the incidence and outcomes of patients experiencing acute elevations in serum creatinine in the primary care setting where people are not subsequently admitted to hospital. The aim of this study was to define this incidence and explore its impact on mortality. Methods: The study cohort was identified by using hospital data bases over a six month period. Inclusion criteria: People with a serum creatinine request during the study period, 18 or over and not on renal replacement therapy. The patients were stratified by a rise in serum creatinine corresponding to the Acute Kidney Injury Network (AKIN) criteria for comparison purposes. Descriptive and survival data were then analysed. Ethical approval was granted from National Research Ethics Service (NRES) Committee South East Coast and from the National Information Governance Board. Results: The total study population was 61,432. 57,300 subjects with ‘no AKI’, mean age 64.The number (mean age) of acute serum creatinine rises overall were, ‘AKI 1’ 3,798 (72), ‘AKI 2’ 232 (73), and ‘AKI 3’ 102 (68) which equates to an overall incidence of 14,192 pmp/year (adult). Unadjusted 30 day survival was 99.9% in subjects with ‘no AKI’, compared to 98.6%, 90.1% and 82.3% in those with ‘AKI 1’, ‘AKI 2’ and ‘AKI 3’ respectively. After multivariable analysis adjusting for age, gender, baseline kidney function and co-morbidity the odds ratio of 30 day mortality was 5.3 (95% CI 3.6, 7.7), 36.8 (95% CI 21.6, 62.7) and 123 (95% CI 64.8, 235) respectively, compared to those without acute serum creatinine rises as defined. Conclusions: People who develop acute elevations of serum creatinine in primary care without being admitted to hospital have significantly worse outcomes than those with stable kidney function