The cost of moderate and severe COPD exacerbations to the Canadian healthcare system

SummaryBackgroundThe cost of exacerbations in chronic obstructive pulmonary disease (COPD) has not been well studied. The aim of this study was to identify and quantify the (average) cost of moderate and severe exacerbations (ME and SE, respectively) from a Canadian perspective.MethodsResources used during ME and SE were identified in a year long prospective, observational study (Resource Utilization Study In COPD (RUSIC)). The units of analysis were ME and SE. Unit costs (2006$CAN), based on provincial, hospital and published sources, were applied to resources. The overall cost per ME and SE were calculated. The population burden of exacerbations was also calculated.ResultsAmong study participants (N=609, aged 68.6±9.4 years, 58.3$126 (N=574) and $515 (N=105), respectively. The average overall cost of a ME was$641. For SEs, the average hospital stay was 10.0 days. The overall mean costs of outpatient, ED and hospitalization services for SE were $114 (N=44),$774 (N=140) and $8669 (N=151), respectively. The average overall cost of a SE was$9557.ConclusionThe economic burden associated with MEs and especially SEs, in Canada, is considerable and likely has a substantial impact on healthcare costs. The overall burden of exacerbations has been estimated in the range of $646 million to$736 million per annum

Cyclotron effective masses in layered metals

Many layered metals such as quasi-two-dimensional organic molecular crystals show properties consistent with a Fermi liquid description at low temperatures. The effective masses extracted from the temperature dependence of the magnetic oscillations observed in these materials are in the range, m^*_c/m_e \sim 1-7, suggesting that these systems are strongly correlated. However, the ratio m^*_c/m_e contains both the renormalization due to the electron-electron interaction and the periodic potential of the lattice. We show that for any quasi-two-dimensional band structure, the cyclotron mass is proportional to the density of states at the Fermi energy. Due to Luttinger's theorem, this result is also valid in the presence of interactions. We then evaluate m_c for several model band structures for the \beta, \kappa, and \theta families of (BEDT-TTF)_2X, where BEDT-TTF is bis-(ethylenedithia-tetrathiafulvalene) and X is an anion. We find that for \kappa-(BEDT-TTF)_2X, the cyclotron mass of the \beta-orbit, m^{*\beta}_c, is close to 2 m^{*\alpha}_c, where m^{*\alpha}_c is the effective mass of the \alpha- orbit. This result is fairly insensitive to the band structure details. For a wide range of materials we compare values of the cyclotron mass deduced from band structure calculations to values deduced from measurements of magnetic oscillations and the specific heat coefficient.Comment: 12 pages, 3 eps figure

Academic freedom: in justification of a universal ideal

This paper examines the justification for, and benefits of, academic freedom to academics, students, universities and the world at large. The paper surveys the development of the concept of academic freedom within Europe, more especially the impact of the reforms at the University of Berlin instigated by Wilhelm von Humboldt. Following from this, the paper examines the reasons why the various facets of academic freedom are important and why the principle should continue to be supported