How does the short-wavelength-sensitive contrast sensitivity function for detection and resolution change with age in the periphery?

To determine the age-related change in the peripheral short-wavelength-sensitive (SWS) grating contrast sensitivity function (CSF), cut-off spatial frequency (acuity) and contrast sensitivity for both a detection and resolution task were measured at 8 degrees eccentricity under conditions of SWS-cone isolation for 51 subjects (19-72 years). The acuity for both the detection and resolution task declined with age, the detection acuity being significantly higher than the resolution acuity at all ages (p

Dual Sequence Simulated Annealing with Round-Robin Approach for University Course Timetabling

The university course timetabling problem involves assigning a given number of events into a limited number of timeslots and rooms under a given set of constraints; the objective is to satisfy the hard constraints (essential requirements) and minimize the violation of soft constraints (desirable requirements). In this study we employed a Dual-sequence Simulated Annealing (DSA) algorithm as an improvement algorithm. The Round Robin (RR) algorithm is used to control the selection of neighbourhood structures within DSA. The performance of our approach is tested over eleven benchmark datasets. Experimental results show that our approach is able to generate competitive results when compared with other state-of-the-art techniques.

“The Double Feature Evil”: Efforts to Eliminate the American Dual Bill

The essay discusses the actions and motivations of various groups that tried to end the practice of double feature film exhibition in the United States during the 1930s and 1940s. Used as a price-cutting strategy, double features were embraced by marginal exhibitors and low-budget producers, but attacked by most major studios and established theatre chains. Methods employed to control the double feature included voluntary bans, governmental legislation, and legal action. During the depression, Franklin D. Roosevelt's New Deal opposed the double feature as a strategy likely to undermine established admission price levels. But the double feature proved resilient and survived all these efforts, as well as an additional series of assaults, based on conservation of energy and materiel, mounted during the Second World War.

Wavelength Dependence of Raman Enhancement from Gold Nanorod Arrays: Quantitative Experiment and Modeling of a Hot Spot Dominated System

Surface-enhanced Raman scattering (SERS) spectra from molecules adsorbed on the surface of vertically aligned gold nanorod arrays exhibit a variation in enhancement factor (EF) as a function of excitation wavelength that displays little correlation with the elastic optical properties of the surface. The key to understanding this lack of correlation and to obtaining agreement between experimental and calculated EF spectra lies with consideration of randomly distributed, sub-10 nm gaps between nanorods forming the substrate. Intense fields in these enhancement “hot spots” make a dominant contribution to the Raman scattering and have a very different spectral profile to that of the elastic optical response. Detailed modeling of the electric field enhancement at both excitation and scattering wavelengths was used to quantitatively predict both the spectral profile and the magnitude of the observed EF.

Dual functional ionic liquids as plasticisers and antimicrobial agents for medical polymers

Contamination of medical devices with bacteria such as Meticillin resistant Staphylococcus aureus (MRSA) is of great clinical concern. Poly(vinyl chloride) is widely used in the production of medical devices, such as catheters. The flexibility of catheter tubing is derived from the addition of plasticisers. Here, we report the design of two dual functional ionic liquids, 1-ethylpyridinium docusate and tributyl(2-hydroxyethyl)phosphonium docusate, which uniquely provide a plasticising effect, and exhibit antimicrobial and antibiofilm-forming activity to a range of antibiotic resistant bacteria. The plasticisation of poly(vinyl chloride) was tailored as a function of ionic liquid concentration. The effective antimicrobial behaviour of both ionic liquids originates from the chemical structure of the anion or cation and is not limited to the length of the alkyl chain on the anion/cation. The design approach adopted will be useful in developing ionic liquids as multi-functional additives for polymers.

Sub-Wavelength Profile 2-D Leaky-Wave Antennas With Two Periodic Layers

A fast and accurate analysis and synthesis technique for high-gain sub-wavelength 2-D Fabry-Perot leaky-wave antennas (LWA) consisting of two periodic metallodielectric arrays over a ground plane is presented. Full-wave method of moments (MoM) together with reciprocity is employed for the estimation of the near fields upon plane wave illumination and the extraction of the radiation patterns of the LWA. This yields a fast and rigorous tool for the characterisation of this type of antennas. A thorough convergence study for different antenna designs is presented and the operation principles of these antennas as well as the radiation characteristics are discussed. Moreover, design guidelines to tailor the antenna profile, the dimensions of the arrays as well as the antenna directivity and bandwidth are provided. A study on the radiation efficiency for antennas with different profiles is also presented and the trade off between directivity and radiation bandwidth is discussed. Numerical examples are given throughout to demonstrate the technique. A finite size antenna model is simulated using commercial software (CST Microstripes 2009) which validates the technique.