Sedation and regional anaesthesia in the adult patient

This review discusses sedation for regional anaesthesia in the adult population. The first section deals with general aspects of sedation and shows that the majority of patients receiving sedation for regional anaesthesia are satisfied and would choose it again. Methods of assessing the level of sedation are discussed with emphasis on clinical measures. The pharmacology of the drugs involved in sedation is discussed, with propofol and remifentanil appearing to be the combination of choice for sedation in regional anaesthesia. The techniques for administering sedation are discussed and replacement of the traditional repeated boluses or continuous infusion with pharmacokinetic and patient-controlled systems is supported. Patient satisfaction studies suggest that patient-controlled systems are preferre

The End-to-End Argument and Application Design: The Role of Trust

Symposium: Rough Consensus and Running Code: Integrating Engineering Principles into Internet Policy Debates, held at the University of Pennsylvania\u27s Center for Technology Innovation and Competition on May 6-7, 2010. Policy debates about the evolution of the Internet show varying degrees of understanding about the underlying technology. A fundamental principle of the design of the Internet, from the early 1980s, is the so-called end-to-end argument articulated in a seminal technical paper. Intended to provide guidance for what kind of capability is built into a network as opposed to the devices that use the network, the end-to-end argument has been invoked in discussions about freedom, neutrality, and other qualities that may be associated with the supply and use of the Internet and with related public policy. This Article builds on the technical discussions of end-to-end to address the design of applications that use the Internet. It explores the role of trust as a factor in decisions about the structure of applications and their interaction with the Internet as part of a larger system

Parallel quantized charge pumping

Two quantized charge pumps are operated in parallel. The total current generated is shown to be far more accurate than the current produced with just one pump operating at a higher frequency. With the application of a perpendicular magnetic field the accuracy of quantization is shown to be $<$20 ppm for a current of $108.9$pA. The scheme for parallel pumping presented in this work has applications in quantum information processing, the generation of single photons in pairs and bunches, neural networking and the development of a quantum standard for electrical current. All these applications will benefit greatly from the increase in output current without the characteristic decrease in accuracy as a result of high-frequency operation

Clinical utility of rosuvastatin and other statins for cardiovascular risk reduction among the elderly

Age is one of the strongest predictors of cardiovascular disease (CVD) risk. Treatment with statins can significantly reduce CVD events and mortality in both primary and secondary prevention. Yet despite the high CVD risk among the elderly, there is underutilization of statins in this population (ie, the treatment-risk paradox). Few studies have investigated the use of statins in the elderly, particularly for primary prevention and, as a result, guidelines for treating the elderly are limited. This is likely due to: uncertainties of risk assessment in older individuals where the predictive value of individual risk factors is decreased; the need to balance the benefits of primary prevention with the risks of polypharmacy, health care costs, and adverse medication effects in a population with decreased life expectancy; the complexity of treating patients with many other comorbidities; and increasingly difficult social and economic concerns. As life expectancy increases and the total elderly population grows, these issues become increasingly important. JUPITER (Justification for the Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin) is the largest primary prevention statin trial to date and enrolled a substantial number of elderly adults. Among the 5695 JUPITER participants ≥70 years of age, the absolute CVD risk reduction associated with rosuvastatin was actually greater than for younger participants. The implications of this JUPITER subanalysis and the broader role of statins among older adults is the subject of this review

Single-parameter non-adiabatic quantized charge pumping

Controlled charge pumping in an AlGaAs/GaAs gated nanowire by single-parameter modulation is studied experimentally and theoretically. Transfer of integral multiples of the elementary charge per modulation cycle is clearly demonstrated. A simple theoretical model shows that such a quantized current can be generated via loading and unloading of a dynamic quasi-bound state. It demonstrates that non-adiabatic blockade of unwanted tunnel events can obliterate the requirement of having at least two phase-shifted periodic signals to realize quantized pumping. The simple configuration without multiple pumping signals might find wide application in metrological experiments and quantum electronics.Comment: 4 pages, 4 figure

UHE nuclei propagation and the interpretation of the ankle in the cosmic-ray spectrum

We consider the stochastic propagation of high-energy protons and nuclei in the cosmological microwave and infrared backgrounds, using revised photonuclear cross-sections and following primary and secondary nuclei in the full 2D nuclear chart. We confirm earlier results showing that the high-energy data can be fit with a pure proton extragalactic cosmic ray (EGCR) component if the source spectrum is \propto E^{-2.6}. In this case the ankle in the CR spectrum may be interpreted as a pair-production dip associated with the propagation. We show that when heavier nuclei are included in the source with a composition similar to that of Galactic cosmic-rays (GCRs), the pair-production dip is not present unless the proton fraction is higher than 85%. In the mixed composition case, the ankle recovers the past interpretation as the transition from GCRs to EGCRs and the highest energy data can be explained by a harder source spectrum \propto E^{-2.2} - E^{-2.3}, reminiscent of relativistic shock acceleration predictions, and in good agreement with the GCR data at low-energy and holistic scenarios.Comment: 4 pages, 4 figures, submitted to A&A Letters (minor changes, two figures replaced, two references added