Assessment of the genetic diversity of some important grape genotypes in India using RAPD markers

Genetic relationships in a set of important grape genotypes in India, comprising cultivated varieties, rootstocks and wild species were analysed using RAPD markers. A total of 250 bands were obtained by 19 informative primers, most of which could clearly distinguish between the wild and cultivated genotypes. Wild species and rootstocks showed a maximum number of bands (205) and the highest polymorphism (94 %), followed by cultivars belonging to Vitis vinifera (165 bands, 90 %), while cultivars from V. labrusca showed only 75 bands of which almost all were monomorphic. Cluster analysis resulted in the formation of three main clusters. Wild species and rootstocks separated early from cultivated genotypes. Cultivated types formed two separate clusters one consisting mainly of the labrusca and the other of the vinifera types. In the cluster of vinifera genotypes, seeded and seedless varieties were further separated into different subgroups. High bootstrap values at most of the nodes supported the stability of the dendrogram. The grouping of most varieties agreed well with previous reports based on morphological characters as well as parentage, emphasizing the suitability of RAPD analysis for such studies. The present report is the first attempt to determine the genetic relationships in important grape genotypes in India using molecular markers.

Studies on Electrolytic preparation of Iron Copper Powders

Factors affecting the physical characteristics and chemical composition of iron-cooper powder deposits obtained by electrolysis, have been investigated. Effect of process variables such as current density, pH, temperature, time, concentration of electrolyte and agitation, has been studied over a wide range, for theoretical interest and to obtain powder deposits of a definite composition. Metallographic examination of iron-copper powder thus prepared after compacting and sintering, has revealed uniform and homogeneous dispersion of the two metals. The technique of preparation presented in this paper is a better substitute to the conventional practice of preparing binary metal powders by mixing and tumbling

High temperature regenerative H.sub.2 S sorbents

Efficient, regenerable sorbents for removal of H.sub.2 S from high temperature gas streams comprise porous, high surface area particles. A first class of sorbents comprise a thin film of binary oxides that form a eutectic at the temperature of the gas stream coated onto a porous, high surface area refractory support. The binary oxides are a mixture of a Group VB or VIB metal oxide with a Group IB, IIB or VIII metal oxide such as a film of V-Zn-O, V-Cu-O, Cu-Mo-O, Zn-Mo-O or Fe-Mo-O coated on an alumina support. A second class of sorbents consist of particles of unsupported mixed oxides in the form of highly dispersed solid solutions of solid compounds characterized by small crystallite size, high porosity and relatively high surface area. The mixed oxide sorbents contain one Group IB, IIB or VIIB metal oxide such as copper, zinc or manganese and one or more oxides of Groups IIIA, VIB or VII such as aluminum, iron or molybdenum. The presence of iron or aluminum maintains the Group IB, IIB or VIIB metal in its oxidized state. Presence of molybdenum results in eutectic formation at sulfidation temperature and improves the efficiency of the sorbent

ISSR-PCR for assessment of genetic relationships among grape varieties cultivated in India

Genetic relationships among 43 varieties cultivated in India were characterized using ISSR PCR. Out of total 139 reproducible fragments generated by 13 informative primers, 96 were polymorphic. The similarity coefficient ranged from 0.65 to 0.96. Cluster analysis resulted in the formation of two main clusters, consisting mainly of Vitis labrusca and V. vinifera types. One single variety belonging to V. rotundifolia James grouped with V. labrusca types but separated initially from them. Two varieties, Lake Emerald and Muscat, were completely outgrouped. Varieties belonging to V. vinifera appeared to be more diverse and separated further into many subgroups. In contrast, V. labrusca types were homogeneous. The results showed that ISSR is an efficient and reliable marker system for genetic analysis of grape cultivars

The Negativity of the Overlap-Based Topological Charge Density Correlator in Pure-Glue QCD and the Non-Integrable Nature of its Contact Part

We calculate the lattice two-point function of topological charge density in pure-glue QCD using the discretization of the operator based on the overlap Dirac matrix. Utilizing data at three lattice spacings it is shown that the continuum limit of the correlator complies with the requirement of non-positivity at non-zero distances. For our choice of the overlap operator and the Iwasaki gauge action we find that the size of the positive core is ~2a (with a being the lattice spacing) sufficiently close to the continuum limit. This result confirms that the overlap-based topological charge density is a valid local operator over realistic backgrounds contributing to the QCD path integral, and is important for the consistency of recent results indicating the existence of a low-dimensional global brane-like topological structure in the QCD vacuum. We also confirm the divergent short-distance behavior of the correlator, and the non-integrable nature of the associated contact part.Comment: 13 pages, 5 figure

Scalar Mesons a0(1450) and sigma(600) from Lattice QCD

We study the a0 and sigma mesons with the overlap fermion in the chiral regime with the pion mass as low as 182 MeV in the quenched approximation. After the eta'pi ghost states are separated, we find that the a0 mass with q\bar{q} interpolation field to be almost independent of the quark mass in the region below the strange quark mass. The chirally extrapolated results are consistent with a0(1450) being the u\bar{d} meson and K0*(1430) being the u\bar{s} meson with calculated masses at 1.42+_0.13 GeV and 1.41+_ 0.12 GeV respectively. We also calculate the scalar mesonium with a tetraquark interpolation field. In addition to the two pion scattering states, we find a state at around 550 MeV. Through the study of volume dependence, we confirm that this state is a one-particle state, in contrast to the two-pion scattering states. This suggests that the observed state is a tetraquark mesonium which is quite possibly the sigma(600) meson.Comment: 11 pages, 9 figures, accepted for publication in Phys. Rev.

Inherently Global Nature of Topological Charge Fluctuations in QCD

We have recently presented evidence that in configurations dominating the regularized pure-glue QCD path integral, the topological charge density constructed from overlap Dirac operator organizes into an ordered space-time structure. It was pointed out that, among other properties, this structure exhibits two important features: it is low-dimensional and geometrically global, i.e. consisting of connected sign-coherent regions with local dimensions 1<= d < 4, and spreading over arbitrarily large space--time distances. Here we show that the space-time structure that is responsible for the origin of topological susceptibility indeed exhibits global behavior. In particular, we show numerically that topological fluctuations are not saturated by localized concentrations of most intense topological charge density. To the contrary, the susceptibility saturates only after the space-time regions with most intense fields are included, such that geometrically global structure is already formed. We demonstrate this result both at the fundamental level (full topological density) and at low energy (effective density). The drastic mismatch between the point of fluctuation saturation (~ 50% of space-time at low energy) and that of global structure formation (<4% of space-time at low energy) indicates that the ordered space-time structure in topological charge is inherently global and that topological charge fluctuations in QCD cannot be understood in terms of individual localized pieces. Description in terms of global brane-like objects should be sought instead.Comment: 10 pages, 3 figures; v2: typos corrected, minor modifications; v3: misprint in Eqs. (2,3) fixe

Glueball Spectrum and Matrix Elements on Anisotropic Lattices

The glueball-to-vacuum matrix elements of local gluonic operators in scalar, tensor, and pseudoscalar channels are investigated numerically on several anisotropic lattices with the spatial lattice spacing ranging from 0.1fm - 0.2fm. These matrix elements are needed to predict the glueball branching ratios in $J/\psi$ radiative decays which will help identify the glueball states in experiments. Two types of improved local gluonic operators are constructed for a self-consistent check and the finite volume effects are studied. We find that lattice spacing dependence of our results is very weak and the continuum limits are reliably extrapolated, as a result of improvement of the lattice gauge action and local operators. We also give updated glueball masses with various quantum numbers.Comment: 22 pages, 16 figures, revtex