Studies on Actinomycetes from Soils of Baffin Island

Investigations were made of the abundance and relative incidence of different types of actinomycetes in soil samples from Baffin Island, Northwest Territories. Numbers were relatively low in all samples examined, and no specific group predominated. Cultures grown at 26°C. showed greater metabolic activity than when grown at 10°C., and isolates from different soils varied in degree of activity. Ammonium nitrogen proved to be the best nitrogen source. A comparatively wide range of carbon compounds was utilized; glucose, fructose, mannitol, raffinose and sucrose were the best sources. Moderate growth of a large number of isolates was also obtained with acetate, fumarate, pyruvate and succinate. With one exception the incidence of actinomycetes antagonistic toward bacteria, yeasts and fungi was remarkably high in the soils studied. The samples did, however, differ in proportion of antagonistic types.Études sur les actionmycètes des sols de l'île de Baffin. On a mené des enquêtes sur l'abondance et l'incidence relative des différents types d'actionmycètes dans des échantillons de sols de l'île de Baffin, Territoires du Nord-Ouest. Tous les échantillons examinés ont donné des comptages relativement bas et aucun groupe spécifique ne dominait. Les cultures venues à 26ºC montraient une plus grande activité métabolique que celles venues à 10ºC, et des isolats de sols différents avaient des degrés d'activité variables. L'azote de l'ammonium s'est révélé être la meilleure source de cet élément. On a utilisé une gamme étendue de composés carbonés : glucose, fructose, mannitol, raffinose et sucrose étaient les meilleures sources de carbone. On a aussi obtenu avec l'acétate, le fumarate, le pyruvate et le succinate une croissance modérée d'un grand nombre d'isolats. A une exception près, l'incidence des actinomycètes antagonistes des bactéries, levures et champignons était remarquablement élevée. Cependant, ces échantillons différaient entre eux dans leurs proportions de types antagonistes

Study of the Linked Dipole Chain Model in heavy quark production at the Tevatron

We present calculations of charm and beauty production at Tevatron within the framework of kT-factorization, using the unintegrated gluon distributions as obtained from the Linked Dipole Chain model. The analysis covers transverse momentum and rapidity distributions and the azimuthal correlations between b and bbar quarks (or rather muons from their decay) which are powerful tests for the different unintegrated gluon distributions. We compare the theoretical results with recent experimental data taken by D0 and CDF collaborations at the Tevatron Run I and II.Comment: 16 page

A Parton Model for Inclusive Semileptonic B Meson Decays

The parton model for semileptonic B meson decays is studied with special attention to the decay distributions. We find that the spectra show dramatic variations when we introduce cuts on the hadronic energy or invariant mass of hadrons. Results for both $b\rightarrow u$ and $b\rightarrow c$ decays are presented. The detailed spectra may help to separate the two types of decays.Comment: 9 pages, DO-TH 93/29, OHSTPY-HEP-T-93-011, September 199

Efficient Symmetry Reduction and the Use of State Symmetries for Symbolic Model Checking

One technique to reduce the state-space explosion problem in temporal logic model checking is symmetry reduction. The combination of symmetry reduction and symbolic model checking by using BDDs suffered a long time from the prohibitively large BDD for the orbit relation. Dynamic symmetry reduction calculates representatives of equivalence classes of states dynamically and thus avoids the construction of the orbit relation. In this paper, we present a new efficient model checking algorithm based on dynamic symmetry reduction. Our experiments show that the algorithm is very fast and allows the verification of larger systems. We additionally implemented the use of state symmetries for symbolic symmetry reduction. To our knowledge we are the first who investigated state symmetries in combination with BDD based symbolic model checking