Detection of wave aberrations in the human eye using a retinoscopy-like technique

The influence of optical aberrations on the retinoscopic reflex is theoretically analyzed from a geometrical point of view. The relationship between the wave aberrations to the ray aberrations is applied to explain the appearance of the retinoscopic patterns for different types of ocular aberrations. Several schematic models of the human eye are tested numerically, showing that a careful retinoscopic examination can detect the usual eye aberrations.     

The role of cobalt,copper, nickel,and zinc in the DNA replication inhibitory activity of p‐aminophenyl triphenylporphyrin

Cationic porphyrins have been widely used as tumor localizers in cancer therapies. When cationic porphyrins are flat they intercalate with double‐stranded DNA, duplexes of RNA or RNA–DNA. The antitumor activity of some cationic porphyrins depends on their interaction with human telomeric quadruplexes. Here, we report that noncationic meso‐(4‐aminophenyl)triphenylporphyrin (H₂TPPNH₂) ( 3 ) and its cobalt, copper, nickel, and zinc metallo derivatives ( 4 – 7 ) have DNA replication inhibitory activity in B16 mouse melanoma line cells. By means of quantification of ³HdTT radio‐labeled DNA, we observed that the nonplanar porphyrin [CoTPPNH₂] has the highest activity against carcinogenic DNA replication. Copyright © 2004 John Wiley & Sons, Ltd.     

Upper bound on the hadronic light-by-light contribution to the muon g - 2

There are indications that hadronic loops in some electroweak observables are almost saturated by parton level effects. Taking this as the hypothesis for this work, we propose a genuine parton level estimate of the hadronic light-by-light contribution to the anomalous magnetic moment of the muon, a(LBL)/(mu)(had). Our quark mass definitions and values are motivated in detail, and the simplicity of our approach allows for a transparent error estimate. For infinitely heavy quarks our treatment is exact, while for asymptotically small quark masses a(LBL)/(mu)(had) is overestimated. Interpolating, this suggests quoting an upper bound. We obtain a(LBL)/(mu)(had)<1.59x10;{-9} (95% C.L.).     

How to make dull cellular automata complex by adding memory: Rule 126 case study

Using Rule 126 elementary cellular automaton (ECA), we demonstrate that a chaotic discrete system — when enriched with memory — hence exhibits complex dynamics where such space exploits on an ample universe of periodic patterns induced from original information of the ahistorical system. First, we analyze classic ECA Rule 126 to identify basic characteristics with mean field theory, basins, and de Bruijn diagrams. To derive this complex dynamics, we use a kind of memory on Rule 126; from here interactions between gliders are studied for detecting stationary patterns, glider guns, and simulating specific simple computable functions produced by glider collisions. © 2010 Wiley Periodicals, Inc. Complexity, 2010     

Fractal zone plates

Fractal zone plates (FZPs), i.e., zone plates with a fractal structure, are described. The focusing properties of this new type of zone plate are compared with those of conventional Fresnel zone plates. It is shown that the axial irradiance exhibited by the FZP has self-similarity properties that can be correlated to those of the diffracting aperture.     

Beneficial Effect of Melatonin Alone or in Combination with Glatiramer Acetate and Interferon β-1b on Experimental Autoimmune Encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is a relevant animal model of multiple sclerosis (MS). Oxidative stress and chronic inflammation play a major role in the pathogenesis of MS and EAE. Melatonin, a neurohormone, has potent anti-inflammatory properties. The aim of our study was to assess the therapeutic properties of melatonin alone or in combination with interferon β-1b (IFNβ-1b) or glatiramer acetate (GA) on EAE. EAE was induced in male Sprague-Dawley rats with an intraperitoneal injection of a homogenate of spinal cord and pig brain. At day 10 post immunization, rats were euthanized, and their brains were immediately excised and processed to measure oxidative stress markers and membrane fluidity. In addition, proinflammatory cytokines were quantified in plasma. Melatonin alone or in combination with GA and IFNβ-1b inhibited the disease process of EAE and the synthesis of proinflammatory cytokines, caused a significant decrement in oxidative stress markers, and preserved the membrane fluidity in the motor cortex, midbrain, and spinal cord. The cumulative index score was significantly reduced in EAE rats treated with melatonin alone or in combination with GA and IFNβ-1b. In conclusion, our findings provide preclinical evidence for the use of melatonin as an adjuvant therapeutic treatment for MS.     

Subtractive imaging in confocal scanning microscopy using a CCD camera as a detector

We report a scheme for the detector system of confocal microscopes in which the pinhole and a large-area detector are substituted by a CCD camera. The numerical integration of the intensities acquired by the active pixels emulates the signal passing through the pinhole. We demonstrate the imaging capability and the optical sectioning of the system. Subtractive-imaging confocal microscopy can be implemented in a simple manner, providing superresolution and improving optical sectioning.