A study of the retinal vascular pathology in the Royal College of Surgeons rat: A model of human retinal degeneration.

The leading causes of loss of vision in the developed world are the degenerative diseases of photoreceptors in particular, age-related macular degeneration (AMD) and retinitis pigmentosa (RP). A common characteristic of these diseases is secondary damage affecting the vascular network, which is apparently initiated by photoreceptor loss. One problem with investigating the vascular consequences of these diseases has been the lack of a suitable animal model that can be used to investigate various potential treatments. This study has developed methods of quantifying retinal vascular damage in the pigmented Royal College of Surgeons (RCS) rat, which is characterised by the formation of vascular complexes and these methods have been used to explore strategies to retard or reverse this damage. This was done with the view to improving the retinal environment, thereby assisting other therapeutic strategies that target the primary defect causing the loss of photoreceptors. The work was divided into three areas: 1) investigation of the vascular effects of progressive photoreceptor loss and development of computerised image analysis to quantify changes, 2) pharmaceutical intervention to modify the normal sequence of events, 3) examination of the effects of RPE sub-retinal transplantation on the vascular network to determine how the retinal vasculature would react to the presence of transplanted human RPE cells at different time-points. These three areas of study validate the use of naturally occurring events in the RCS rat to provide a model of vascular pathology in human retinal degenerative diseases. This contrasts with previous models, which have relied on creating wounds to simulate conditions that occurring in the diseased human retina

Anisotropy of the Mobility of Pentacene from Frustration

The bandstructure of pentacene is calculated using first-principles density functional theory. A large anisotropy of the hole and electron effective masses within the molecular planes is found. The band dispersion of the HOMO and the LUMO is analyzed with the help of a tight-binding fit. The anisotropy is shown to be intimately related to the herringbone structure.Comment: Accepted for publication in Synthetic Metal

A computerized analysis of the entire retinal ganglion cell population and its spatial distribution in adult rats

AbstractIn adult albino (SD) and pigmented (PVG) rats the entire population of retinal ganglion cells (RGCs) was quantified and their spatial distribution analyzed using a computerized technique. RGCs were back-labelled from the optic nerves (ON) or the superior colliculi (SCi) with Fluorogold (FG). Numbers of RGCs labelled from the ON [SD: 82,818±3,949, n=27; PVG: 89,241±3,576, n=6) were comparable to those labelled from the SCi [SD: 81,486±4,340, n=37; PVG: 87,229±3,199; n=59]. Detailed methodology to provide cell density information at small scales demonstrated the presence of a horizontal region in the dorsal retina with highest densities, resembling a visual streak

The performance of concrete exposed to marine environments: predictive modelling and use of laboratory/on site test method

This paper reports an approach by which laboratory based testing and numerical modelling can be combined to predict the long term performance of a range of concretes exposed to marine environments. Firstly, a critical review of the test methods for assessing the chloride penetration resistance of concrete is given. The repeatability of the different test results is also included. In addition to the test methods, a numerical simulation model is used to explore the test data further to obtain long-term chloride ingress trends. The combined use of testing and modelling is validated with the help of long-term chloride ingress data from a North Sea exposure site. In summary, the paper outlines a methodology for determining the long term performance of concrete in marine environments

Optimal Inverse Design of Magnetic Field Profiles in a Magnetically Shielded Cylinder

Magnetic shields that use both active and passive components to enable the generation of a tailored low-field environment are required for many applications in science, engineering, and medical imaging. Until now, accurate field nulling, or field generation, has only been possible over a small fraction of the overall volume of the shield. This is due to the interaction between the active field-generating components and the surrounding high-permeability passive shielding material. In this paper, we formulate the interaction between an arbitrary static current flow on a cylinder and an exterior closed high-permeability cylinder. We modify the Green’s function for the magnetic vector potential and match boundary conditions on the shield’s interior surface to calculate the total magnetic field generated by the system. We cast this formulation into an inverse optimization problem to design active–passive magnetic field shaping systems that accurately generate any physical static magnetic field in the interior of a closed cylindrical passive shield. We illustrate this method by designing hybrid systems that generate a range of magnetic field profiles to high accuracy over large interior volumes, and simulate them in real-world shields whose passive components have finite permeability, thickness, and axial entry holes. Our optimization procedure can be adapted to design active–passive magnetic field shaping systems that accurately generate any physical user-specified static magnetic field in the interior of a closed cylindrical shield of any length, enabling the development and miniaturization of systems that require accurate magnetic shielding and control

The Oedipal Paradigm in Group Development

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68383/2/10.1177_104649647300400302.pd

Opto-mechanical measurement of micro-trap via nonlinear cavity enhanced Raman scattering spectrum

High-gain resonant nonlinear Raman scattering on trapped cold atoms within a high-fineness ring optical cavity is simply explained under a nonlinear opto-mechanical mechanism, and a proposal using it to detect frequency of micro-trap on atom chip is presented. The enhancement of scattering spectrum is due to a coherent Raman conversion between two different cavity modes mediated by collective vibrations of atoms through nonlinear opto-mechanical couplings. The physical conditions of this technique are roughly estimated on Rubidium atoms, and a simple quantum analysis as well as a multi-body semiclassical simulation on this nonlinear Raman process is conducted.Comment: 7 pages, 2 figure

Contemporary percutaneous treatment of unprotected left main coronary stenoses: initial results from a multicenter registry analysis 1994-1996.

BACKGROUND: Coronary artery bypass surgery (CABG) has been considered the therapy of choice for patients with unprotected left main (ULMT) coronary stenoses. Selected single-center reports suggest that the results of percutaneous intervention may now approach those of CABG. METHODS AND RESULTS: To assess the results of percutaneous ULMT treatment from a wide variety of experienced interventional centers, we requested data on consecutive patients treated after January 1, 1994, from 25 centers. One hundred seven patients were identified who were treated either electively (n=91) or for acute myocardial infarction (n=16). Of patients treated electively, 25% were considered inoperable, and 27% were considered high risk for bypass surgery. Primary treatment included stents (50%), directional atherectomy (24%), and balloon angioplasty (20%). Follow-up was 98.8% complete at 15+/-8 months. Results varied considerably, depending on presentation and treatment. For patient

Making visible ‘hidden’ intentions and potential choices: international students in intercultural communication

The study reported in this paper examines the experiences of Chinese and Vietnamese international students in engaging in their institutional written discourse at an Australian university. The study highlights the significance of exploring the real accounts of the students as the ‘insiders’ and uncovering students’ individual potential choices and intentions as their ‘seemingly unrecognized’ values in producing their own texts in English as a second language. In particular, based on international students’ reflection on their intentions and potential choices in academic practices, the study signals how the taken-for-granted institutional conventions may contribute to silencing or marginalizing the possibilities for alternative approaches to knowledge and communication within the higher education institutional context