Liver Transplantation in Adults

Human liver transplantation has been possible since 1967. We report our experience in 32 adult patients who received liver transplants at the University of Pittsburgh over a 16‐month period. Survival data, method utilized for patient selection, costs, and morbidity of the procedure are discussed. Copyright © 1982 American Association for the Study of Liver Disease

A new method for isolating turbulent states in transitional stratified plane Couette flow

We present a new adaptive control strategy to isolate and stabilize turbulent states in transitional, stably stratified plane Couette flow in which the gravitational acceleration (non-dimensionalized as the bulk Richardson number$Ri$) is adjusted in time to maintain the turbulent kinetic energy (TKE) of the flow. We demonstrate that applying this method at various stages of decaying stratified turbulence halts the decay process and allows a succession of intermediate turbulent states of decreasing energy to be isolated and stabilized. Once the energy of the initial flow becomes small enough, we identify a single minimal turbulent spot, and lower-energy states decay to laminar flow. Interestingly, the turbulent states which emerge from this process have very similar time-averaged$Ri$, but TKE levels different by an order of magnitude. The more energetic states consist of several turbulent spots, each qualitatively similar to the minimal turbulent spot. This suggests that the minimal turbulent spot may well be the lowest-energy turbulent state which forms a basic building block of stratified plane Couette flow. The fact that a minimal spot of turbulence can be stabilized, so that it neither decays nor grows, opens up exciting opportunities for further study of spatiotemporally intermittent stratified turbulence.The EPSRC grant EP/K034529/1 entitled ‘Mathematical Underpinnings of Stratified Turbulence’ is gratefully acknowledged for supporting the research presented here.This is the author accepted manuscript. The final version is available from Cambridge University Press via https://doi.org/10.1017/jfm.2016.62

Quantum AdS_5 x S^5 superstring in the AdS light-cone gauge

We consider the AdS_5 x S^5 superstring in the light-cone gauge adapted to a massless geodesic in AdS5 in the Poincare patch. The resulting action has a relatively simple structure which makes it a natural starting point for various perturbative quantum computations. We illustrate the utility of this AdS light-cone gauge action by computing the 1-loop and 2-loop corrections to the null cusp anomalous dimension reproducing in a much simpler and efficient way earlier results obtained in conformal gauge. This leads to a further insight into the structure of the superstring partition function in non-trivial background.Comment: 21pages, Late

Classifying Alarms: Seeking Durability, Credibility, Consistency, and Simplicity

Alongside the development and testing of new audible alarms intended to support International Electrotechnical Commission 60601-1-8, a global standard concerned with alarm safety, the categories of risk that the standard denotes require further thought and possible updating. In this article, we revisit the origins of the categories covered by the standard. These categories were based on the ways that tissue damage can be caused. We consider these categories from the varied professional perspectives of the authors: human factors, semiotics, clinical practice, and the patient or family (layperson). We conclude that while the categories possess many clinically applicable and defensible features from our range of perspectives, the advances in alarm design now available may allow a more flexible approach. We present a three-tier system with superordinate, basic, and subordinate levels that fit both within the thinking embodied in the current standard and possible new developments

Bench surgery and renal autotransplantation in the pediatric patient

Surgery at the work bench has developed as a by-product of the extensive experience in renal homotransplantation. A basic tenet of the transplant operation is organ survival outside the human body for a finite period. Recent refinements in kidney preservation have extended the permissible ex vivo period to several days. Consequently, extracorporeal procedures have become highly feasible and a practical adjunct for operative renal surgery. Bench surgery and autotransplantation thus far have been underexploited in pediatric surgery despite potential applicability in a significant number of childhood lesions. At the University of Colorado Medical Center, 14 patients have been treated by extracorporeal renal surgery and have been reported in part.1-3 The purpose of this communication is to review the technical aspects of this new operative procedure, present two case reports, and discuss the potential role of extracorporeal surgery and renal autotransplantation as it pertains to the pediatric patient

Theoretical and experimental exploration of finite sample size effects on the propagation of surface waves supported by slot arrays (article)

This is the final version of the article. Available from American Physical Society via the DOI in this record.The dataset associated with this article is in ORE at: http://hdl.handle.net/10871/28223The propagation of surface waves supported by a finite array of slots perforated on a zero thickness perfect electrically conducting screen is studied both experimentally and theoretically. To generate numerical results, the integral equation satisfied by the electric field in the slots is efficiently solved by means of Galerkin’s method, treating the metal as perfectly conducting. The finite size of the array along the direction of propagation creates a family of states of higher momentum and lower amplitude than the single mode for the corresponding infinite array. These modes are spaced in momentum with a periodicity inversely proportional to the length of the array. In addition, the finite width in the transverse direction produces a set of higher frequency modes due to this additional quantization. Both effects arising from finite sample length and width are explained by the theoretical model and validated experimentallyThe authors wish to acknowledge financial support from the Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom, via the EPSRC Centre for Doctoral Training in Metamaterials (Grant No. EP/L015331/1). R.R.B. and F.M. acknowledge financial support from the Spanish MINECO (Grant No. TEC2013-41913-P) and the Spanish Junta de Andalucía (Grant No. P12-TIC-1435)

Theoretical and experimental exploration of finite sample size effects on the propagation of surface waves supported by slot arrays (article)

This is the final version of the article. Available from American Physical Society via the DOI in this record.The dataset associated with this article is in ORE at: http://hdl.handle.net/10871/28223The propagation of surface waves supported by a finite array of slots perforated on a zero thickness perfect electrically conducting screen is studied both experimentally and theoretically. To generate numerical results, the integral equation satisfied by the electric field in the slots is efficiently solved by means of Galerkin’s method, treating the metal as perfectly conducting. The finite size of the array along the direction of propagation creates a family of states of higher momentum and lower amplitude than the single mode for the corresponding infinite array. These modes are spaced in momentum with a periodicity inversely proportional to the length of the array. In addition, the finite width in the transverse direction produces a set of higher frequency modes due to this additional quantization. Both effects arising from finite sample length and width are explained by the theoretical model and validated experimentallyThe authors wish to acknowledge financial support from the Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom, via the EPSRC Centre for Doctoral Training in Metamaterials (Grant No. EP/L015331/1). R.R.B. and F.M. acknowledge financial support from the Spanish MINECO (Grant No. TEC2013-41913-P) and the Spanish Junta de Andalucía (Grant No. P12-TIC-1435)

ResQbot: a mobile rescue robot with immersive teleperception for casualty extraction

In this work, we propose a novel mobile rescue robot equipped with an immersive stereoscopic teleperception and a teleoperation control. This robot is designed with the capability to perform safely a casualty-extraction procedure. We have built a proof-of-concept mobile rescue robot called ResQbot for the experimental platform. An approach called “loco-manipulation” is used to perform the casualty-extraction procedure using the platform. The performance of this robot is evaluated in terms of task accomplishment and safety by conducting a mock rescue experiment. We use a custom-made human-sized dummy that has been sensorised to be used as the casualty. In terms of safety, we observe several parameters during the experiment including impact force, acceleration, speed and displacement of the dummy’s head. We also compare the performance of the proposed immersive stereoscopic teleperception to conventional monocular teleperception. The results of the experiments show that the observed safety parameters are below key safety thresholds which could possibly lead to head or neck injuries. Moreover, the teleperception comparison results demonstrate an improvement in task-accomplishment performance when the operator is using the immersive teleperception

On the extraordinary optical transmission in parallel plate waveguides for non-TEM modes

This is the final version of the article. Available from Optical Society of America via the DOI in this record.Extraordinary transmission has been recently measured in a parallel plate waveguide (PPWG) through a metal strip with a patterned 1-D periodic array of circular holes, the metal strip being embedded inside the PPWG. Wood’s anomaly and the extraordinary transmission peak (EOT) were detected for transverse electric (TE) mode excitation at frequencies higher than those found for TEM mode excitation. In this paper we provide an explanation for this frequency shift by decomposing the problem of a TE mode impinging on the 1-D array of holes into two problems of plane waves impinging obliquely on 2-D periodic arrays of holes. By then solving the integral equation for the electric field on the surface of the holes, the origin of the frequency shift is proved both mathematically and physically in terms of the symmetries present in the system.Engineering and Physical Sciences Research Council (EPSRC) (EP/L015331/1) and “Junta de Andalucía” (P12-TIC-1435)

Dispersion of surface waves supported by truncated metasurfaces

This is the author accepted manuscript. The final version is available from IEEE via the DOI in this record.The effects introduced in the dispersion of surface waves supported by a metasurface consisting of a negligible thickness perfectly conducting screen perforated with a finite array of slots are studied by means of a very efficient implementation of Galerkin’s version of the Method of Moments with a DeltaGap excitation. A family of higher frequency modes each of which is periodically repeated in the momentum spectrum with decreasing amplitude is found in contrast to the single mode dispersion obtained for an infinite array.The authors wish to acknowledge financial support from the Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom, via the EPSRC Centre for Doctoral Training in Metamaterials (Grant No. EP/L015331/1)