HIV arthritis

Whether reexposure of varicella-immune persons to varicella-zoster virus would protect against or predispose to development of zoster was analyzed. The rate of zoster in 511 leukemic recipients of varicella vaccine who had 1 or > 1 dose of varicella vaccine and in those who did or did not have a household exposure to varicella was determined. A Kaplan-Meier life-table analysis revealed that the incidence of zoster was lower in those given > 1 dose of vaccine (P < .05). A Cox proportional hazards analysis showed that both household exposure to varicella and receipt of > 1 dose of vaccine were highly protective (P < .01) against zoster. Thus, the risk of zoster is decreased by reexposure to varicella-zoster virus, either by vaccination or by close exposure to varicella.     

Linear operator theory of channeled spectropolarimetry

Channeled spectropolarimetry is a snapshot method of measuring the spectral and polarization content of light. Wave-number domain amplitude modulation is employed to encode all four Stokes component spectra into a single optical power spectrum. We model the channeled spectropolarimeter as a linear operator, which facilitates treatment of nonideal effects and provides a convenient framework for simulations, calibration, and reconstruction. The operator's singular value decomposition is treated with analytic and computational approaches. This analysis highlights the importance of the choice of object space in constraining and imparting prior knowledge to linear reconstructions of data from underdetermined systems.     

Analysis of computed tomographic imaging spectrometers. I. Spatial and spectral resolution

Computed tomographic imaging spectrometers measure the spectrally resolved image of an object scene in an entirely different manner from traditional whisk-broom or push-broom systems, and thus their noise behavior and data artifacts are unfamiliar. We review computed tomographic imaging spectrometry (CTIS) measurement systems and analyze their performance, with the aim of providing a vocabulary for discussing resolution in CTIS instruments, by illustrating the artifacts present in their reconstructed data and contributing a rule-of-thumb measure of their spectral resolution. We also show how the data reconstruction speed can be improved, at no cost in reconstruction quality, by ignoring redundant projections within the measured raw images.     

Chemical composition,antinutritional constituents,precaecal crude protein and amino acid digestibility in three unconventional tropical legumes in broilers

Three tropical crop seeds, namely Enterolobium cyclocarpum, Mucuna pruriens and Centrosema pubescens, were assessed for their contents of chemical constituents, antinutritional factors (ANFs), crude protein (CP) and amino acid (AA) digestibility. Their meals were incorporated into broiler diets in place of maize starch at two levels (150 and 300 g kg^?1). Four hundred and twenty 1‐day‐old broilers were randomly assigned to seven experimental diets on a weight basis and used to determine CP and AA digestibility in the diets and seeds, and performance of the birds. The CP contents were 237, 278 and 252 g kg^?1 DM in E. cyclocarpum, M. pruriens and C. pubescens, respectively. Compared to the basal diet, the digestibility of CP and AAs in the diets and seeds was significantly (p < 0.05) reduced at higher level of inclusion of E. cyclocarpum and M. pruriens but increased at higher C. pubescens inclusion. Digestibility of arginine, threonine and lysine in the C. pubescens meal diets was similar to that in the basal diet. Digestibility values of CP and AAs were least in E. cyclocarpum. Aspartic acid was the least and glutamic acid the most digested AA in all the seeds. Among the essential AAs, threonine was the least digested AA, while leucine (in E. cyclocarpum and M. pruriens) and lysine (in C. pubescens) had the highest digestibility with values of 65, 73 and 72%, respectively. Feed intake, body weights and weight gain in the birds were significantly (P < 0.05) reduced in the E. cyclocarpum and M. pruriens diets but increased in the C. pubescens diets compared to the basal diet. Results of the study suggest that, based on the CP content and AA profiles in the seeds, they have potential for poultry feeding. The presence of ANFs, especially in E. cyclocarpum and M. pruriens, however, could be a major limitation in their use in poultry feeding. Copyright © 2006 Society of Chemical Industry     

Selective polarization imager for contrast enhancements in remote scattering media

Conventional intensity imaging through turbid media suffers from rapid loss of image contrast due to light scattering from particles or random variations of refractive index. This paper features the development of an active imaging, snapshot, system design and postprocessing algorithms that differentiate between radiation that scatters or reflects from remote, obscured objects and the radiation from the scattering media itself through a combination of polarization difference imaging, channel blurring, and Fourier spatial filtering. The produced sensor acquires and processes image data in real time, yielding improved image contrasts by factors of 10 or greater for dense water vapor obscurants.     

Decoding movement intent patterns based on spatiotemporal and adaptive filtering method towards active motor training in stroke rehabilitation systems

Neural Computing and Applications - Upper extremity (UE) neuromuscular dysfunction critically affects post-stroke patients from performing activities of daily life. In this regard, various...     

Scanning tunnelling engineering

The great potential for building molecular scale machines and other structures was first noted by Richard Feynman (1960). He also proposed the development of tools to construct nanoscale mechanisms and devices. The range of technology that he proposed is now called nanotechnology, a term coined by Taniguchi (1974). Emergence of STM and related technology should greatly facilitate the development of nanotechnology in the decades to come. Franks' (1987b) review of nanotechnology notes the tremendous potential of STM-derived tools for what he terms ‘scanning tunneling engineering’. However, STM technology can also augment the ‘bottom up’ approaches to nanotechnology, exemplified for example by Forrest Carter's (1979, 1980, 1982, 1983) proposals for building molecular electronic devices (nanocomputers) using synthetic ‘modular chemistry’ and related techniques of supramolecular chemistry (Kuhn & Mobius, 1971; Kuhn, 1983; Lehn, 1980, 1988). A multi-tip STM system integrated with an optical microscope was proposed in 1986 as a ‘nanotechnology workstation’ suitable for scanning tunnelling engineering (Schneiker & Hameroff, 1988). In this paper, we describe an overview of scanning tunnelling engineering, present concepts for nanosensors and nanoswitches, and discuss design considerations for dual tip STM. Finally, we repeat an announcement of a series of ‘Feynman’ prizes for miniature STM.     

Economic evaluation of small-scale photovoltaic hybrid systems for mini-grid applications in far north Cameroon

A comparison between photovoltaic hybrid systems (PVHS), standalone photovoltaic (PV) and standalone diesel generator options is performed using the net present value (NPV) technique. A typical village mini-grid energy demand of 7.08 kWh/day is considered in the computation of energy costs and breakeven grid distances. A first sensitivity analysis is conducted using remote diesel prices of 0.8 €/l, 0.98 €/l, 1.12 €/l, 1.28 €/l with a PV module cost of 7.5 €/Wp. A second sensitivity analysis is also done using PV module costs of 5.25 €/Wp, 6 €/Wp, 6.75 €/Wp, 7.5 €/Wp with a diesel price of 1.12 €/l. The energy cost for the diesel option was found to be 0.812 €/kWh at a diesel fuel price of 1.12 €/l. The sensitivity analyses showed that minimum energy costs were attained in PVHS at renewable energy fractions in the range 82.6–95.3%. In the second sensitivity analysis the energy costs and breakeven grid distances were found to be in the ranges 0.692–0.785 €/kWh and 5.1–5.9 km respectively. For a PV module cost of 5.25 €/Wp, the lowest energy cost for the PVHS option was 0.692 €/kWh at a final renewable energy fraction of 95.3% with the diesel generator hours being 37 h compared to 2075 h in the standalone diesel generator option. Consequently, a 30% reduction in custom duties and taxes on imported PV modules and sub-systems would increase the use of small-scale and climate friendly PV mini-grids in remote areas of far north Cameroon that have an annual insolation of at least 5.55 kWh/m²/day.     

SpiNNaker: Fault tolerance in a power- and area- constrained large-scale neuromimetic architecture

SpiNNaker is a biologically-inspired massively-parallel computer designed to model up to a billion spiking neurons in real-time. A full-fledged implementation of a SpiNNaker system will comprise more than 10⁵ integrated circuits (half of which are SDRAMs and half multi-core systems-on-chip). Given this scale, it is unavoidable that some components fail and, in consequence, fault-tolerance is a foundation of the system design. Although the target application can tolerate a certain, low level of failures, important efforts have been devoted to incorporate different techniques for fault tolerance. This paper is devoted to discussing how hardware and software mechanisms collaborate to make SpiNNaker operate properly even in the very likely scenario of component failures and how it can tolerate system-degradation levels well above those expected.     

Modeling and optimization for a prismatic snapshot imaging polarimeter

Thin birefringent prisms placed near an image plane introduce sinusoidal fringes onto a 2D polarized scene making possible a snapshot imaging polarimeter, which encodes polarization information into the modulation of the fringes. This approach was introduced by Oka and Kaneko [Opt. Express 11, 1510 (2003)], who analyzed the instrument through the Mueller calculus. We show that the plane-wave assumption adopted in the Mueller theory can introduce unnecessary error in a polarimeter design. To directly take prism effects such as beam splitting and deviating into accounts we introduce a geometric imaging model, which allows for a versatile simulation of the birefringent prisms and provides a means for optimization. A calcite visible system is investigated as an example, which essentially shows how each design parameter affects the overall image quality and how to modify the polarimeter design to optimize overall performance. The approach is applicable to any prismatic imaging polarimeter with different prism materials and different working wavelengths.