Onion culture

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Unitarity of black hole evaporation in final-state projection models

Almheiri et al. have emphasized that otherwise reasonable beliefs about black hole evaporation are incompatible with the monogamy of quantum entanglement, a general property of quantum mechanics. We investigate the final-state projection model of black hole evaporation proposed by Horowitz and Maldacena, pointing out that this model admits cloning of quantum states and polygamous entanglement, allowing unitarity of the evaporation process to be reconciled with smoothness of the black hole event horizon. Though the model seems to require carefully tuned dynamics to ensure exact unitarity of the black hole S-matrix, for a generic final-state boundary condition the deviations from unitarity are exponentially small in the black hole entropy; furthermore observers inside black holes need not detect any deviations from standard quantum mechanics. Though measurements performed inside old black holes could potentially produce causality-violating phenomena, the computational complexity of decoding the Hawking radiation may render the causality violation unobservable. Final-state projection models illustrate how inviolable principles of standard quantum mechanics might be circumvented in a theory of quantum gravity.Comment: (v3) 27 pages, 16 figures. Expanded discussion of measurements inside black hole

Causes and damage to fruits and vegetables during shipment

Cover title.Includes bibliographical references

Evaluation of aerosolized medications during parabolic flight maneuvers

The goal was to visually evaluate the effect gravity has on delivery of medications by the use of various aerosol devices. During parabolic flight the same four aerosols were retested as performed in studio ground tests. It appears that the Cetacaine spray and the Ventolin inhaler function without failure during all test. The pump spray (Nostril) appeared to function normally when the container was full, however it appeared to begin to fail to deliver a full mist with larger droplet size when the container was nearly empty. The simple hand spray bottle appeared to work when the container was full and performed progressively worse as the container was emptied. During Apollo flights, it was reported that standard spray bottles did not work well, however, they did not indicate why. It appears that we would also conclude that standard spray bottles do not function as well in zero gravity by failing to produce a normal mist spray. The standard spray bottle allowed the fluid to come out in a narrow fluid stream when held with the nozzle either level or slightly tilted upward

A study of aminopeptidases from lactic streptococci : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Biochemistry at Massey University

Two arninopeptidase enzymes from the proteolytic system of Streptococcus lactis 4760 have been studied. An X-Prolyl dipeptidyl arninopeptidase has been purified and characterised. The enzyme has a native molecular weight of approximately 150 kDa determined by gel filtration, and a subunit molecular weight of 83 000, determined by denaturing polyacrylarnide gel electrophoresis, showing the native enzyme to be a dimer. It is inhibited by phenyl methyl sulphonyl fluoride and is active over a pH range of 6 - 9. A range of X-Prolyl-amido methyl coumarin (X-Pro-AMC) derivatives with different aminoacyl residues in the X position have been used to define the steady state kinetic parameters. The Km and kcat values obtained with all of the X-Pro-AMC substrates tested were similar, with the exception of Glu-Pro-AMC, which gave a somewhat higher Km value. The action of the enzyme in degrading small peptides has been studied. It was found to be capable of removing X-Proline residues from peptides, except where two proline residues are situated in consecutive positions. A Lysyl-arninopeptidase has been partially purified and its characteristics studied. This enzyme has been shown to have a native molecular weight of approximately 78 000. It hydrolyses lysyl-, arginyl-, and leucyl-arnido methyl coumarin derivatives, but has little or no activity with other arninoacyl-AMC substrates. It also catalyses the removal of lysine and arginine residues from the amino-terminus of short peptides. The partially purified arninopeptidase preparation also has endopeptidase activity which is probably due to contamination by a separate enzyme. The individual and combined effects of these two enzymes on -casein-derived oligopeptides (produced by proteolytic action of the S.lactis proteinase) have been studied. These results indicate that these enzymes may be important in degradation of some casein-derived peptides during cheese ripening, while other peptides are resistant to hydrolysis

Implementing NMC standards for learning, and assessing in practice(2006): a demonstration of effective partnership between a higher education institution and NHS Trust placement partners

This paper provides an account of the collaborative approach taken to implement professional standards in teaching, learning and assessing in practice for nursing and midwifery. How challenges for effective partnership working between university and placement/practice education provider were overcome are presented. Processes and issues which arose when new national regulatory professional standards of practice education were introduced are highlighted. The partnership work ensured a robust process to locally interpreting and implementing the NMC Standards for Supporting Learning and Assessing in Practice (2006). This was achieved and resulted in a county wide agreed implementation of the Standards across NHS Oxfordshire and beyond. The key requirements of the Standards and the challenges identified are presented together with how issues were addressed. The approach taken by an established partnership working group is described and the products of the process are detailed, including listing 'top tips' for successful partnership working

The Hydrogeology and Water Supply Problems in North-Central Chile

The north-central zone of Chile is described with respect to groundwater supply problems. In this region, groundwater is almost exclusively obtained from the thin alluvium in the main transverse valleys, which descend from the Andes in those sections where the valleys cross the northerly trending "central valley." Because of the steep groundwater gradients prevailing, the groundwater resources are closely related to seasonal recharge. As the area is arid to semiarid and has been showing indications of increasing aridity over the past few years, water supply problems are proving to be a serious development constraint. Throughout the area, many examples of insufficient water supply may be encountered, and the problems of water use management and the utilization for industrial purposes of supplies such as seawater, brines, and sewage are now being considered

Soliton dynamics in the Gross–Pitaevskii equation: splitting, collisions and interferometry

Bose–Einstein condensates with attractive interactions have stable 1D solutions in the form of bright solitary-waves. These solitary waves behave, in the absence of external potentials, like macroscopic quantum particles. This opens up a wide array of applications for the testing of quantum mechanical behaviours and precision measurement. Here we investigate these applications with particular focus on the interactions of bright solitary-waves with narrow potential barriers. We first study bright solitons in the Gross–Pitaevskii equation as they are split on Gaussian and δ-function barriers, and then on Gaussian barriers in a low energy system. We present analytic and numerical results determining the general region in which a soliton may not be split on a finite width potential barrier. Furthermore, we test the sensitivity of the system to quantum fluctuations. We then study fast-moving bright solitons colliding at a narrow Gaussian potential barrier. In the limiting case of a δ-function barrier, we show analytically that the relative norms of the outgoing waves depends sinusoidally on the relative phase of the incoming waves, and determine whether the outgoing waves are bright solitons. We use numerical simulations to show that outside the high velocity limit nonlinear effects introduce a skew to the phase-dependence. Finally, we use these results to analyse the process of soliton interferometry. We develop analyses of both toroidal and harmonic trapping geometries for Mach–Zehnder interferometry, and then two implementations of a toroidal Sagnac inter- ferometer, also giving the analytical determination of the Sagnac phase in such systems. These results are again verified numerically. In the Mach–Zehnder case, we again probe the systems sensitivity to quantum fluctuations