Design of an automated multicapillary instrument with fraction collection for DNA mutation discovery by constant denaturant capillary electrophoresis (CDCE)

A fundamental goal ingenomics is the discovery of genetic variation that contributes to disease states or to differential drug responses. Single nucleotide polymorphism (SNP) detection has been the focus of much attention in the study of genetic variation over the last decade. These SNPs typically occur at a frequency greater than 1% in the human genome. Recently, low-frequency alleles are also being increasingly recognized as critical to obtain an improved understanding of the correlation between genetic variation and disease. Although many methods have been reported for the discovery and scoringof SNPs, sensitive, automated, and cost-effective methods and platforms for the discovery of low-frequency alleles are not yet readily available. We describe here an automated multicapillary instrument for high-throughput detection of low-frequency alleles from pooled samples using constant denaturant capillary electrophoresis. The instrument features high optical sensitivity (1 x 10(-12) M fluorescein detection limit), precise and stable temperature control (+/- 0.01degrees C), and automation for sample delivery, injection, matrix replacement, and fraction collection. The capillary array is divided into six groups of four capillaries, each of which can be independently set at any temperature ranging from room temperature to 90 degrees C. The key performance characteristics of the instrument are reported.     

Ni–Zn ferrite-loaded superparamagnetic amorphous carbon nanotubes through a facile route

Partial filling of mixed ferrite (Ni_0.5Zn_0.5Fe₂O₄; NZFO) nanoparticles into the amorphous carbon nanotubes (aCNTs) cavity is achieved by simple mixing of the aqueous dispersions of the two (aCNTs and NZFO) at room temperature. The process of incorporation of the nanoparticles into the aCNT cavity is solely mediated by the capillary action of the liquid. NZFO nanoparticles were homogeneously dispersed in the aqueous solution but after mixing they are sparsely distributed into the aCNT channel as a result of the capillary action. The encapsulation of the nanoparticles into the aCNTs amorphous shield was established by means of X-ray diffraction, transmission electron microscopy, Fourier transformed infrared spectroscopy, and Raman spectroscopic analysis. Such entrapment of the nanoparticles causes the composite nanotubes superparamagnetic in nature with blocking temperature (T _B) at 15 K. However, compared to the powder NZFO nanoparticles, T _B appears more sharply and at relatively lower temperature. Low filling density and the spatial confinement of the nanoparticles lessen the inter-particle interactions and the polydispersity within the NZFO nanoparticles which are manifested in their altered magnetic behavior.     

Congruences on quasi completely regular semirings

Semigroup Forum - We study quasi completely regular semirings through their congruence structures.     

Multi-item multi-period optimal production problem with variable preparation time in fuzzy stochastic environment

In this paper, a multi-item multi-period optimal production control problem with variable preparation time and limited available space is formulated and solved. Here, the rate of production is assumed to be a function of time and considered as a control variable. Also the demand is linearly stock dependent. The preparation time is assumed and considered to be a variable. Production and set-up costs are dependent on preparation time. Here, preparation time influences the production cost negatively and set-up cost positively. Also the space constraint is assumed to be fuzzy-random in nature and with the help of Mean Chance Constraint Method, the fuzzy-random space constraint is converted to a crisp one. This problem is formulated as an optimal control problem and solved with the help of Genetic Algorithm (GA). Best optimum and the second best optimum results are obtained and these are also presented in tabular forms and graphically.     

Clan structure in high energypn,pp andp\bar p interactions

We have analysed ourpn data at 400 GeV (corresponding to a centre-of-mass energy \(\sqrt s = 27.5\) GeV) together with otherpp and \(p\bar p\) data in the centre of mass energy range 11.5–900 GeV. The fits of all these distributions to a negative binomial distribution are performed. The variations in the fitted average multiplicity and in the inverse of the fitted parameterk are obtained with respect to the centre of mass energy. An assessment of the single diffractive component in the multiplicity distribution is made and its variation with the centre of mass energy discussed. The average number of clans and the average charged multiplicity per clan are determined and the centre of mass energy dependences shown.     

Synthesis of iron oxide nanoparticles under oxidizing environment and their stabilization in aqueous and non-aqueous media

Synthesis of magnetite (Fe₃O₄) nanoparticles under oxidizing environment by precipitation from aqueous media is not straightforward because Fe²⁺ gets oxidized to Fe³⁺ and thus the ratio of Fe³⁺:Fe²⁺=2:1 is not maintained during the precipitation. A molar ratio of Fe³⁺:Fe²⁺ smaller than 2:1 has been used by many to compensate for the oxidation of Fe²⁺ during the preparation. In this work, we have prepared iron oxide nanoparticles in air environment by the precipitation technique using initial molar ratios Fe³⁺:Fe²⁺?2:1. The phases of the resulting powders have been determined by several techniques. It is found that the particles consist mainly of maghemite with little or no magnetite phase. The particles have been suspended in non-aqueous and aqueous media by coating the particles with a single layer and a bilayer of oleic acid, respectively. The particle sizes, morphology and the magnetic properties of the particles and the ferrofulids prepared from these particles are reported. The average particle sizes obtained from the TEM micrographs are 14, 10 and 9 nm for the water, kerosene and dodecane-based ferrofluids, respectively, indicating a better dispersion in the non-aqueous media. The specific saturation magnetization (σ_s) value of the oleic-acid-coated particles (∼53 emu/g) is found to be lower than that for the uncoated particles (∼63 emu/g). Magnetization σ_s of the dodecane-based ferrofluid is found to be 10.1 emu/g for a volume fraction of particles ?=0.019. Zero coercivity and zero remanance on the magnetization curves indicate that the particles are superparamagnetic (SPM) in nature.     

On quasi completely regular semirings

We extend the concepts of a completely π-regular semigroup and a GV semigroup to semirings and find a semiring analogue of a structure theorem on GV semigroups. We also show that a semiring S is quasi completely regular if and only if S is an idempotent semiring of quasi skew-rings.     

On the second cohomology of nilpotent orbits in exceptional Lie algebras

In [1], the second de Rham cohomology groups of nilpotent orbits in all the complex simple Lie algebras are described. In this paper we consider non-compact non-complex exceptional Lie algebras, and compute the dimensions of the second cohomology groups for most of the nilpotent orbits. For the rest of cases of nilpotent orbits, which are not covered in the above computations, we obtain upper bounds for the dimensions of the second cohomology groups.     

On the application of a new formulation of nonlinear eddy viscosity based on anisotropy to numerical ocean models

The present paper explores the derivation of an alternative nonlinear eddy viscosity formulation based on Reynolds stress anisotropy and its implementation to numerical ocean models. This formulation takes into account the vorticity in addition to the mean strain rate. The proposed formulation does not include the stability function method which is a common approach in eddy viscosity calculations used in the present state-of-the-art numerical ocean models. Instead, it depends on the second invariant of anisotropy. Initially, the performance of the formulation is checked through a simple channel flow simulation. Consequently for model calibration, an idealised experiment of mixed-layer entrainment into stably stratified flow has been simulated and compared to empirical data. For sensitivity studies related to shear and stable stratification, concept of steady-state Richardson number is applied for homogeneous shear layer. Finally, the performance of the new formulation is tested by implementing it into one-dimensional General Ocean Turbulence Model. Furthermore, a realistic oceanic test case of a storm has been investigated considering different physical processes for the Fladenground Experiment (FLEX’ 76) in the northern North Sea and the results have been compared to the measured data. The main results signify that the overall performance of the nonlinear eddy viscosity model with a different value of steady-state Richardson number is as good as the Mellor–Yamada model in terms of predictability, and the eddy viscosity and diffusivity profiles follow the principle of law of the wall. Additionally, the present formulation does not require computing the stability functions and the ease of implementation into numerical ocean models gives the present formulation an upper hand over the existing formulations in the field of turbulence modelling in oceanography.     

High-load, hybrid Si-ROMP reagents

The combination of norbornenyl-tagged (Nb-tagged) silica particles and functionalized Nb-tagged monomers for the generation of hybrid Si-ROMP reagents and scavengers is reported. Specifically Si-ROMP-derived bis-acid chloride, dichlorotriazine, and triphenylphosphine scavenger/reagents have been grafted from the surface of silica particles utilizing surface-initiated, ring-opening metathesis polymerization (ROMP). These hybrid polymeric materials combine the physical properties of current immobilized silica reagents and represent a key advancement in load by merging the inherent tunable properties of the ROMP-derived oligomers with silica supports for application in a parallel synthesis.