Periodic cyclic homology of Iwahori-Hecke algebras

We determine the periodic cyclic homology of the Iwahori-Hecke algebras \Hecke_q, for q \in \CC^* not a ``proper root of unity.'' (In this paper, by a {\em proper root of unity} we shall mean a root of unity other than 1.) Our method is based on a general result on periodic cyclic homology, which states that a ``weakly spectrum preserving'' morphism of finite type algebras induces an isomorphism in periodic cyclic homology. The concept of a weakly spectrum preserving morphism is defined in this paper, and most of our work is devoted to understanding this class of morphisms. Results of Kazhdan--Lusztig and Lusztig show that, for the indicated values of $q$, there exists a weakly spectrum preserving morphism \phi_q : \Hecke_q \to J, to a fixed finite type algebra $J$. This proves that $\phi_q$ induces an isomorphism in periodic cyclic homology and, in particular, that all algebras \Hecke_q have the same periodic cyclic homology, for the indicated values of $q$. The periodic cyclic homology groups of the algebra \Hecke_1 can then be determined directly, using results of Karoubi and Burghelea, because it is the group algebra of an extended affine Weyl group.Comment: 24 pages, LaTe

Analytical model of fast ion behavior in current hole tokamak plasmas

A qualitative theoretical approach is proposed for the study of fast ion behavior in tokamak plasmas with a current hole. For the equilibrium magnetic configuration in a current hole tokamak we employ a simplified model based on an analytical approximation of the poloidal flux function shape. For that the radial extent of the plasma core area with zero rotational transform is used as a characteristic parameter. The modification of the fast ion orbit topology, as caused by the current hole, is studied. The model yields manageable analytical expressions describing completely the current hole effect on the confinement domains as well as on the boundaries separating the regions of different-type orbits in the constants-of-motion space. Subject of investigation is the current hole effect, both on the convective transport of fast ions induced by their slowing down as well as on the diffusive transport caused by pitch angle scattering. The influence of slowing down on the distribution functions of energetic particles (charged fusion products, NBI ions) in current hole tokamak plasmas is calculated and illustrated. The approach proposed is tested for a specific JET current hole scenario and the results are compared with numerical Fokker-Planck predictions.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France

Audit in practice : surveillance for hypoglycaemia in the neonatal paediatric intensive care unit

Hypoglycaemia in neonates is defined as a blood glucose ≤ 2.6 mmol/1. Certain categories of babies are at particularly high risk of developing hypoglycaemia in the first few days of life, and are routinely monitored in the Neonatal Paediatric Intensive Care Unit by reagent strips using a reflectance meter. This study shows that the current glucose meter, in use in the entire Department of Health, is unreliable in the detection of hypoglycaemia in neonates, but is accurate for values of blood glucose >3 mmol/1. For this reason, laboratory blood glucose estimation should be used for screening of neonatal hypoglycaemia until such time that a more reliable technique for bedside assay of blood glucose becomes available in the Neonatal Paediatric Intensive Care Unit.peer-reviewe

The Response of Retail Interest Rates to Factor Forecasts of Money Market Rates in Major European Economies

The recent financial crisis has underlined that banks no longer simply accumulate deposits and lend a fraction to their clients. Instead they use interbank markets and structured finance to increase their loan book. This has implications for the understanding of interest rate pass through since a large number of interest rates and macro variables influence the retail rates they set on loans and deposits. This paper uses Stock-Watson factor forecasts to predict market interest rates which are then used as the basis for setting retail rates. We find a significant role for forecasts of future interest rates in determining short- and long-run pass through, and we argue that models which do not include future rates are misspecified.forecasting, factor models, interest rate pass-through

Interest rate Pass-Through in the Major European Economies - The Role of Expectations

Much of the literature on interest rate pass through assumes banks set retail rates in relation to contemporary market rates. We argue that future rates also matter, and if forecasts of future rates are included, the empirical specifications of many previous studies are misspecified. Including forecasts requires careful choice of the data and models used to make forecasts: a large number of variables could influence future market rates, suggesting that factor forecasts method may be an appropriate method to consider. We evaluate forecasts before including them in a model of retail rate adjustment for five interest rates in five European countries and the euro area as a whole. We find a significant role for forecasts of future interest rates in determining short- and long-run pass through, and we show that models which do not include future rates do not provide accurate estimates.forecasting, factor models, interest rate pass-through.