Selective COX-2 inhibitors and risk of myocardial infarction

Selective inhibitors of cyclooxygenase- 2 ( COX- 2, ` coxibs') are highly effective anti-inflammatory and analgesic drugs that exert their action by preventing the formation of prostanoids. Recently some coxibs, which were designed to exploit the advantageous effects of non- steroidal anti-inflammatory drugs while evading their side effects, have been reported to increase the risk of myocardial infarction and atherothrombotic events. This has led to the withdrawal of rofecoxib from global markets, and warnings have been issued by drug authorities about similar events during the use of celecoxib or valdecoxib/ parecoxib, bringing about questions of an inherent atherothrombotic risk of all coxibs and consequences that should be drawn by health care professionals. These questions need to be addressed in light of the known effects of selective inhibition of COX- 2 on the cardiovascular system. Although COX- 2, in contrast to the cyclooxygenase-1 ( COX- 1) isoform, is regarded as an inducible enzyme that only has a role in pathophysiological processes like pain and inflammation, experimental and clinical studies have shown that COX- 2 is constitutively expressed in tissues like the kidney or vascular endothelium, where it executes important physiological functions. COX- 2- dependent formation of prostanoids not only results in the mediation of pain or inflammatory signals but also in the maintenance of vascular integrity. Especially prostacyclin ( PGI(2)), which exerts vasodilatory and antiplatelet properties, is formed to a significant extent by COX- 2, and its levels are reduced to less than half of normal when COX- 2 is inhibited. This review outlines the rationale for the development of selective COX- 2 inhibitors and the pathophysiological consequences of selective inhibition of COX- 2 with special regard to vasoactive prostaglandins. It describes coxibs that are currently available, evaluates the current knowledge on the risk of atherothrombotic events associated with their intake and critically discusses the consequences that should be drawn from these insights. Copyright (C) 2005 S. Karger AG, Basel

Photo sensor array technology development

The development of an improved capability photo sensor array imager for use in a Viking '75 type facsimile camera is presented. This imager consists of silicon photodiodes and lead sulfide detectors to cover a spectral range from 0.4 to 2.7 microns. An optical design specifying filter configurations and convergence angles is described. Three electronics design approaches: AC-chopped light, DC-dual detector, and DC-single detector, are investigated. Experimental and calculated results are compared whenever possible using breadboard testing and tolerance analysis techniques. Results show that any design used must be forgiving of the relative instability of lead sulfide detectors. A final design using lead sulfide detectors and associated electronics is implemented by fabrication of a hybrid prototype device. Test results of this device show a good agreement with calculated values

Non-equilibrium fixed points of coupled Ising models

Driven-dissipative systems are expected to give rise to non-equilibrium phenomena that are absent in their equilibrium counterparts. However, phase transitions in these systems generically exhibit an effectively classical equilibrium behavior in spite of their non-equilibrium origin. In this paper, we show that multicritical points in such systems lead to a rich and genuinely non-equilibrium behavior. Specifically, we investigate a driven-dissipative model of interacting bosons that possesses two distinct phase transitions: one from a high- to a low-density phase---reminiscent of a liquid-gas transition---and another to an antiferromagnetic phase. Each phase transition is described by the Ising universality class characterized by an (emergent or microscopic) $\mathbb{Z}_2$ symmetry. They, however, coalesce at a multicritical point, giving rise to a non-equilibrium model of coupled Ising-like order parameters described by a $\mathbb{Z}_2 \times \mathbb{Z}_2$ symmetry. Using a dynamical renormalization-group approach, we show that a pair of non-equilibrium fixed points (NEFPs) emerge that govern the long-distance critical behavior of the system. We elucidate various exotic features of these NEFPs. In particular, we show that a generic continuous scale invariance at criticality is reduced to a discrete scale invariance. This further results in complex-valued critical exponents and spiraling phase boundaries, and it is also accompanied by a complex Liouvillian gap even close to the phase transition. As direct evidence of the non-equilibrium nature of the NEFPs, we show that the fluctuation-dissipation relation is violated at all scales, leading to an effective temperature that becomes "hotter" and "hotter" at longer and longer wavelengths. Finally, we argue that this non-equilibrium behavior can be observed in cavity arrays with cross-Kerr nonlinearities.Comment: 19+11 pages, 7+9 figure

Feasibility study of the ultraviolet spectral analysis of the lunar surface

Ultraviolet spectral analysis of granite, gabbro, and serpentinite samples to determine feasibility of mapping surface composition of moo

Energy Spectrum and Turbulent Scales in a Plane Air Jet

The energy spectra and longitudinal length scales measured in a free plane jet are presented. The actual convective velocity was used in determining the scales. The results show a universal spectral distribution along the axis but no obvious similarity in the large scale motion off the axis. The results are limited to x/D \u3c 60. The measured scales suggest a noticeable increase of the microscale along the lateral coordinate but an essentially constant value along the axis. However the macroscales, increasing linearly along the axis do not show any similarity off the axis

New nickel-base wrought superalloy with applications up to 1253 K (1800 F)

Alloy possesses combination of high tensile strength at low and intermediate temperatures to 1033 K with good rupture strength at high temperatures to 1255 K. Alloy has promise for turbine disk application in future gas turbine engines and for wrought integrally bladed turbine wheel; thickness and weight of disk portion of wheel could be reduced

Embedding the concept of ecosystems services:The utilisation of ecological knowledge in different policy venues

The concept of ecosystem services is increasingly being promoted by academics and policy makers as a means to protect ecological systems through more informed decision making. A basic premise of this approach is that strengthening the ecological knowledge base will significantly enhance ecosystem health through more sensitive decision making. However, the existing literature on knowledge utilisation, and many previous attempts to improve decision making through better knowledge integration, suggest that producing ‘more knowledge’ is only ever a necessary but insufficient condition for greater policy success. We begin this paper by reviewing what is already known about the relationship between ecological knowledge development and utilisation, before introducing a set of theme issue papers that examine—for the very first time—how this politically and scientifically salient relationship plays out across a number of vital policy venues such as land-use planning, policy-level impact assessment, and cost–benefit analysis. Following a detailed synthesis of the key findings of all the papers, this paper identifies and explores new research and policy challenges in this important and dynamic area of environmental governance

Applications of the AVE-Sesame data sets to mesoscale studies

Data collected by the lightning data concentrator are available for research. The Mark 3 McIDAS capability provides greater flexibility for the Marshall user community and serves as a model of future UW McIDAS to remote computer links. Techniques were investigated for the display of dynamic 3-D data sets. To date the most promising display technology is a polarized two CRT perspective display which allows both dynamic 3-D images and graphics presentations with full color capability. Algorithms were for the preparation and display of conventional and satellite based weather data in 3-D. These include gridding, contouring, and streamlining processors which operate on both real time and case study data bases. An upper air trajectory model was implemented which creates a display of air parcel trajectories in perspective 3-D. A subsystem for the generation of 3-D solid surface display with shading and hidden surface display with shading and hidden surface removal was tested and its products are currently being evaluated. Motion parallax introduced by moving the point of observation during display is an important depth cue, which, when added to the perspective parallax creates a very realistic appearing display