Reserve requirements: A modern perspective

The discussion in many money and banking textbooks would suggest that the Federal Reserve requires depository institutions to hold a minimum level of non-interest-earning reserves because (1) reserve requirements are a monetary policy tool that allows the Fed to expand the money supply and lower interest rates, and (2) reserve requirements improve the safety and soundness of depository institutions. This article argues that this "conventional wisdom" view is too narrow. ; The Fed often uses reserve requirement changes, the authors contend, to achieve non-monetary-policy objectives, as it did in 1992 to improve the profitability of depository institutions and ease the credit crunch of that time. The authors also challenge the notion that higher reserve requirements necessarily lead to greater safety and lower default risk for depository institutions. ; The article examines the relationship between reserve requirement changes and monetary policy, with the aim of demonstrating the recent, limited usefulness of reserve requirements as a monetary policy tool. The article proposes a more modern view of reserve requirements as a tax on depository institutions, ponders who really bears this tax, and summarizes a large and growing literature suggesting that perceived bank profitability is inversely affected by announced changes in reserve requirement ratios. The article also provides new evidence that the 1992 reserve requirement reductions were not associated with an increase in default risk for financial institutions that issue reservable instruments, as the conventional view would suggest.Monetary policy ; Financial institutions ; Bank reserves

Lectures on detonation physics introduction to theory of detonation shock dynamics

These lectures review some basic results of detonation theory and are specialized to serve as an introduction to the theory of Detonation Shock Dynamics (DSD). The theory of DSD is a time-dependent, multi-dimensional theory for the propagation of near-Chapman-Jouguet (CJ) detonations. This theory is especially relevant to applications of detonation propagation in condensed explosives and the basic dynamics in freely propagating gaseous explosives as well. The theory that we present is based on rigorous mathematical arguments and rational approximations for an assumed model of the explosive material. The material is described by the compressible, reactive Euler equations for a given equation of state and kinetic rate law for the release of exothermic, chemical energy. This theory is the basis for the engineering "Method of Detonation Shock Dynamics", that is now being used in the design of explosive systems. Lectures on the Method of Detonation Shock Dynamics are being planned as a sequel. This first set of lectures were given in the summer of 1992 at Eglin Air Force Base.US Air Force Wright Lab 93/0

Modeling deflagration-to-detonation transition in granular explosive pentaerythritol tetranitrate

Based on an approach suggested by Stewart et al. [Phys. Fluids6, 2515 (1994)] we develop a model to simulate deflagration-to-detonation transition (DDT) in pentaerythritol tetranitrate (PETN) powders. The model uses a continuum mechanics formulation of conservation laws for a mixture of solid reactants and gas products, written in terms of mixture quantities plus two independent variables used to account for exothermic conversion of solid reactants into gas products, and compaction associated with pore collapse and grain rearrangement. We propose a simple empirical dependence of the reaction rate on the initial bed compaction that allows us to calibrate the model for a wide range of initial conditions. For the solid reactants we use a wide-ranging equation of state(EOS) developed by Davis and co-workers in a series of papers [Proceedings of the Tenth International Symposium on Detonation, 1993, pp. 369–376; Explosive Effects and Applications (Springer, New York, 1998), Chap. 1, Combust. Flame120, 399 (2000); Proceedings of the 12th International Symposium Detonation, San Diego, CA, 2002, pp. 624–631; . ONR 333-05-2; Proceedings of the Eighth Detonation Symposium, 1985, pp. 785–795; Proceedings of the 11th International Symposium on Detonation, 1998, pp. 303–308]. The EOS for powder uses the P-αmodel of Herrmann [J. Appl. Phys.40, 2490 (1969)] and Carrol and Holt [J. Appl. Phys.43, 759 (1972)]. To close the system, we suggest phenomenological closure relations, consistent with the limit of a compressible inert material and of a solid fully reactive material, such that the EOS can be posed only in terms of mixture quantities and the reaction and compaction variables. We demonstrate the model’s ability to capture DDT in PETN powders by matching transients typically observed in experiments through simulation. We show that for flows calculated using nonideal EOSs and complex reaction kinetics such as those formulated in our model, it is possible to define a separatrix, i.e., the C+ characteristic that separates the C+ characteristics that evolve into the detonation front from those that evolve away from it. We comment on the effects that the variability in the grain microstructure in PETN explosive powder beds can have on the overall mechanics of DDT and discuss possible ways to model this.This work has been supported by U.S. Air Force Research Laboratory, Munitions Directorate Grant No. F08630-00-1-0002 and the Air Force Office of Scientific Research, Mathematics Grant No. FA9550-06-1-0044

Miniaturization of explosive technology and microdetonics

Abstract Condensed phase explosives used in conventional explosive systems have a charge size on the order of a meter or a sizable fraction of a meter. We discuss a range of issues, theoretical, computational and experimental, required to scale the size of explosive systems downwards by a factor of one hundred to one thousand, applications and prospects for a ubiquitous new technology

Transforming health care: the policy and politics of service reconfiguration in the UK’s four health systems

Public involvement in service change has been identified as a key facilitator of health care transformation (Foley et al., 2017) but little is known about how health policy influences whether and how organisations involve the public in change processes. This qualitative study compares policy and practice for involving the public in major service changes across the UK's four health systems (England, Northern Ireland, Wales and Scotland). We analysed policy documents, and conducted interviews with officials, stakeholders, NHS staff and public campaigners (total number of interviewees = 47). Involving the public in major service change was acknowledged as a policy challenge in all four systems. Despite ostensible similarities, there were some clear differences between the four health systems' processes for involving patients and the public in major changes to health services. The extent of central Government oversight, the prescriptiveness of Government guidance, the role for intermediary bodies and arrangements for independent scrutiny of contentious decisions all vary. We analyse how health policy in the four systems has used 'sticks' and 'sermons' to promote particular approaches, and conclude that both policy and the wider system context within which health care organisations try to effect change are significant, and understudied aspect of contemporary practice

CBS domains form energy-sensing modules whose binding of adenosine ligands is disrupted by disease mutations

CBS domains are defined as sequence motifs that occur in several different proteins in all kingdoms of life. Although thought to be regulatory, their exact functions have been unknown. However, their importance was underlined by findings that mutations in conserved residues within them cause a variety of human hereditary diseases, including (with the gene mutated in parentheses): Wolff-Parkinson-White syndrome (γ2 subunit of AMP-activated protein kinase); retinitis pigmentosa (IMP dehydrogenase-1); congenital myotonia, idiopathic generalized epilepsy, hypercalciuric nephrolithiasis, and classic Bartter syndrome (CLC chloride channel family members); and homocystinuria (cystathionine β-synthase). AMP-activated protein kinase is a sensor of cellular energy status that is activated by AMP and inhibited by ATP, but the location of the regulatory nucleotide-binding sites (which are prime targets for drugs to treat obesity and diabetes) was not characterized. We now show that tandem pairs of CBS domains from AMP-activated protein kinase, IMP dehydrogenase-2, the chloride channel CLC2, and cystathionine β-synthase bind AMP, ATP, or S-adenosyl methionine,while mutations that cause hereditary diseases impair this binding. This shows that tandem pairs of CBS domains act, in most cases, as sensors of cellular energy status and, as such, represent a newly identified class of binding domain for adenosine derivatives