Taut distance-regular graphs and the subconstituent algebra

We consider a bipartite distance-regular graph $G$ with diameter $D$ at least 4 and valency $k$ at least 3. We obtain upper and lower bounds for the local eigenvalues of $G$ in terms of the intersection numbers of $G$ and the eigenvalues of $G$. Fix a vertex of $G$ and let $T$ denote the corresponding subconstituent algebra. We give a detailed description of those thin irreducible $T$-modules that have endpoint 2 and dimension $D-3$. In an earlier paper the first author defined what it means for $G$ to be taut. We obtain three characterizations of the taut condition, each of which involves the local eigenvalues or the thin irreducible $T$-modules mentioned above.Comment: 29 page

The Terwilliger algebra of an almost-bipartite P- and Q-polynomial association scheme

Let $Y$ denote a $D$-class symmetric association scheme with $D \geq 3$, and suppose $Y$ is almost-bipartite P- and Q-polynomial. Let $x$ denote a vertex of $Y$ and let $T=T(x)$ denote the corresponding Terwilliger algebra. We prove that any irreducible $T$-module $W$ is both thin and dual thin in the sense of Terwilliger. We produce two bases for $W$ and describe the action of $T$ on these bases. We prove that the isomorphism class of $W$ as a $T$-module is determined by two parameters, the dual endpoint and diameter of $W$. We find a recurrence which gives the multiplicities with which the irreducible $T$-modules occur in the standard module. We compute this multiplicity for those irreducible $T$-modules which have diameter at least $D-3$.Comment: 22 page

Impact of varying intensities of blue-light exposure on 3T3 cells

There is the need to develop a compatible sterilisation method for hybrid biomaterials. High-intensity blue light in the 405 nm region has been shown to be an effective bacterial decontamination method [1], to cause no noticeable damage to the gross structure of type-I collagen monomer (when treated at 10 mW/cm2) [2], and to have no noticeable effect on 3T3 cell viability, growth rate, redox state or lactate dehydrogenase (LDH) leakage (at 1.0 mW/cm2) [2]. The purpose of this research was to investigate the effect of varying the blue-light intensity on the 3T3 cell response parameters

Combined treatment of biomatrices with nisin and pulsed electric fields as a potential decontamination method?

Pulsed electric field (PEF) treatment has been shown to achieve bacterial inactivation in collagen gels whilst retaining the ability of the collagen to function as a biomaterial [1, 2]. Nisin, an antimicrobial peptide, has been used widely as a food preservative and has shown bactericidal action against a number of Gram-positive bacteria [3]. The potential of nisin to increase the efficacy of PEF disinfection of collagen gels to be used for tissue engineering applications was investigated

DT fusion neutron irradiation of BNL-LASL superconductor wires, BPNL nickel and molybdenum, ORNL magnesium oxide, UW-LLL metallic foils, and LLL aluminum tensile

The experimental procedure for testing the samples is given. No test results are indicated. (MOW