Hidden dimers and the matrix maps: Fibonacci chains re-visited

The existence of cycles of the matrix maps in Fibonacci class of lattices is well established. We show that such cycles are intimately connected with the presence of interesting positional correlations among the constituent `atoms' in a one dimensional quasiperiodic lattice. We particularly address the transfer model of the classic golden mean Fibonacci chain where a six cycle of the full matrix map exists at the centre of the spectrum [Kohmoto et al, Phys. Rev. B 35, 1020 (1987)], and for which no simple physical picture has so far been provided, to the best of our knowledge. In addition, we show that our prescription leads to a determination of other energy values for a mixed model of the Fibonacci chain, for which the full matrix map may have similar cyclic behaviour. Apart from the standard transfer-model of a golden mean Fibonacci chain, we address a variant of it and the silver mean lattice, where the existence of four cycles of the matrix map is already known to exist. The underlying positional correlations for all such cases are discussed in details.Comment: 14 pages, 2 figures. Submitted to Physical Review

Expression Pattern of Myogenic Regulatory Transcription Factor mRNAs in the Embryo and Adult Labeo rohita (Hamilton, 1822)

Understanding the regulation of skeletal muscle development is important to meet the increasing demand of Indian major carp Labeo rohita. Myogenic regulatory factors (MRFs) along with myocyte specific enhancer factor 2 (MEF2) play the pivotal role in the determination and differentiation of skeletal muscle. The majority of skeletal muscle genes require both MRFs and MEF2 family members to activate their transcription. In this study, the expression pattern of MyoD, myf-5, myogenin, and MEF2A was observed from 6 h after fertilization to 12 months of age using semiquantitative RT-PCR as well as real-time PCR method. MyoD and myf-5 mRNAs were expressed at high level at the early embryonic stages. Myogenin and MEF2A were expressed after MyoD and myf-5 and remained active up to adult stage. Expression of MyoD was lower than that of Myf-5 after the 5th month. Partial sequencing of MyoD, myf-5, and MEF2A was done to draw phylogeny. In phylogenetic study, Labeo MyoD, MEF2A and myf-5 were found to be closely related to those of common carp. The present investigation suggests that the four transcription factors play pivotal role in the regulation of muscle growth of Labeo rohita in an overlapping and interconnected way

Modulating antioxidant activity and the controlled release capability of laccase mediated catechin grafting of chitosan

Laccase from ascomycete Myceliophthora thermophila was used for the oxidation and grafting of catechin (CA) and chitosan (CS). The enzymatic grafting of CA into CS resulted in the improvement of natural properties of chitosan films. The successful grafting of CA to CS was supported by UV-Visible and Fourier transform infrared (FT-IR) spectroscopies. The differences in the molecular weight and the degree of deacetylation of the CS affected on the enzymatic grafting rate and thus on the film properties like swelling behaviour, erosion rate, thermal property, tensile strength and breaking strain. The CS films prepared by enzymatic grafting presented high antioxidant activity compared to native CS films. The controlled release profiles of methylene blue and coomassie brilliant blue dye, having different acidity/basicity properties, loaded films were also studied with different release medium. The types of molecule loaded into films, the preparation manner of films and the release medium were decisive parameters affecting the release rate.This research was carried out by the Research Group of MaterialsModification at Pontificia Universidad Católica del Perú PUCP. Theauthors would like to acknowledge to the support of Dirección deGestión de la Investigación (DGI) and the Chemistry Departmentat Pontificia Universidad Católica del Perú PUCP for instrumentalanalysis.info:eu-repo/semantics/publishedVersio

Prenatal arsenic exposure and drowning among children in Bangladesh

There is increasing concern regarding adverse effects of prenatal arsenic exposure on the neurodevelopment of children. We analyzed mortality data for children, who were born to 11,414 pregnant women between 2002 and 2004, with an average age of 5 years of follow-up. Individual drinking-water arsenic exposure during pregnancy was calculated using tubewell water arsenic concentration between last menstrual period and date of birth. There were 84 drowning deaths registered, with cause of death ascertained using verbal autopsy (International Classification of Diseases, 10th revision, codes X65–X70). The prenatal water arsenic exposure distribution was tertiled, and the risk of drowning mortality was estimated by Cox proportional hazard models, adjusted for potential confounders. We observed a significant association between prenatal arsenic exposure and drowning in children aged 1–5 years in the highest exposure tertile (HR=1.74, 95% CI: 1.03–2.94). This study showed that in utero arsenic exposure might be associated with excess mortality among children aged 1–5 years due to drowning

Ag-TiO2 Nanoparticle Codoped SiO2 Films on ZrO2 Barrier-Coated Glass Substrates with Antibacterial Activity in Ambient Condition

ABSTRACT Anatase TiO2 and Ag nanoparticles (NPs) codoped SiO2 films were prepared by the sol-gel method. Proportionate amounts of 3-(glycidoxypropyl)trimethoxysilane (GLYMO), tetraethylorthosilicate (TEOS) and 3-(methacryloxypropyl)trimethoxysilane (MEMO) derived inorganic-organic silica sol, commercially available dispersed anatase TiO2 NPs, and AgNO3 were used to prepare the sols. The films were prepared on ZrO2 (cubic) precoated soda-lime glass substrates by a single-dipping technique and heat-treated at 450 °C in air and H2/Ar atmosphere to obtain hard, relatively porous, and transparent coatings of thickness >600 nm. The ZrO2 barrier layer was previously applied on soda-lime glass to restrict the diffusion of Ag into the substrate. The Ag-TiO2 NPs incorporated SiO2 films were intense yellow in color and found to be fairly stable at ambient condition for several days under fluorescent light. These films show a considerable growth inhibition on contact with the gram negative bacteria E. coli