Self-consistent Calculation of Real Space Renormalization Group Flows and Effective Potentials

We show how to compute real space renormalization group flows in lattice field theory by a self-consistent method. In each step, the integration over the fluctuation field (high frequency components of the field) is performed by a saddle point method. The saddle point depends on the block-spin. Higher powers of derivatives of the field are neglected in the actions, but no polynomial approximation in the field is made. The flow preserves a simple parameterization of the action. In this paper we treat scalar field theories as an example.Comment: 52 pages, uses pstricks macro, three ps-figure

Biopreservation of hepatocytes: current concepts on hypothermic preservation, cryopreservation, and vitrification

Isolated liver cells (primarily isolated hepatocytes) have found important applications in science and medicine over the past 40 years in a wide range of areas, including physiological studies, investigations on liver metabolism, organ preservation and drug de-toxification, experimental and clinical transplantation. An integral component of many of these works is the need to store the isolated cells, either for short or long-term periods. This review covers the biopreservation of liver cells, with a focus on the history of liver cell biopreservation, the application of hypothermia for short-term storage, standard cryopreservation methods for isolated hepatocytes, the biopreservation of other types of liver cells, and recent developments such as vitrification of hepatocytes. By understanding the basis for the different approaches, it will be possible to select the best options for liver cell biopreservation in different applications, and identify ways to improve preservation protocols for the future.Fil: Fuller, Barry J.. University College London; Estados UnidosFil: Petrenko, Alexander Y.. Ukraine Academy of Sciences; UcraniaFil: Rodriguez, Joaquin Valentin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Secretaria de Ciencia y Técnica. Centro Binacional de Investigación en Criobiología Clínica y Aplicada; ArgentinaFil: Somov, Alexander Y.. Ukraine Academy of Sciences; UcraniaFil: Balaban, Cecilia Lucía. Universidad Nacional de Rosario. Secretaria de Ciencia y Técnica. Centro Binacional de Investigación en Criobiología Clínica y Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Guibert, Edgardo Elvio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Secretaria de Ciencia y Técnica. Centro Binacional de Investigación en Criobiología Clínica y Aplicada; Argentin

Analysis of forest product trade relationships between Turkey and European Union member states

The countries have needed to strengthen their trade relationships in the face of increasing competition conditions with globalization and a lot of unions emerged all over the world. The European Union, remaining in the foreground as an economical, commercial and political factor in these unions, possesses considerable influence, which a lot of countries want to be involved in. Turkey, being in the European integration process, looks for a place in European Union (EU) with its own resources and production power. Production and foreign trade data of the forest products industry, being among Turkey’s important sectors, were compared with 25 different EU countries by using hierarchical cluster analysis, and Turkey’s trade relationship was determined. The production amounts, import and exportamounts and the values, between 2002 and 2006, belonging to the EU member countries and Turkey were used. It has been found that all countries could be divided into nine different groups according tocountries’ forest products industry structures. Competition advantage is experienced in the board sector but not in the paper and lumber sectors. The forest products industry sectors of Turkey have the capacity to compete with EU countries

Examination of forest products trade between Turkey and European Union countries with gravity model approach

The success of getting in the foreign trade forms one of the basic stones of economic development for countries. The current and potential trading volume among countries and determining the main factors affecting trade are quite important. The trade currents of the European Union (EU) countries and Turkey in the forest products industry field were analyzed by the gravity model in this study. For this reason, the panel data method was used for 2000 - 2006 periods. The results show the existence of a high degree of trade integration between Turkey and EU. The estimated gravity models explained 63% of the variation regarding the volume of bilateral trade flows in the EU and Turkey. Furthermore, it was determined that GDP had a positive effect on the amount of foreign trade while distance had a negativeeffect; and Turkey has lower trading volume with the EU countries than its potential regarding the forest products industry field

Theory of Current-Induced Breakdown of the Quantum Hall Effect

By studying the quantum Hall effect of stationary states with high values of injected current using a von Neumann lattice representation, we found that broadening of extended state bands due to a Hall electric field occurs and causes the breakdown of the quantum Hall effect. The Hall conductance agrees with a topological invariant that is quantized exactly below a critical field and is not quantized above a critical field. The critical field is proportional to $B^{3/2}$ and is enhanced substantially if the extended states occupy a small fraction of the system.Comment: 5 pages, RevTeX, final version to appear in PR

Characteristics of a novel secreted zinc-dependent endopeptidase of Bacillus intermedius

A novel zinc-dependent metalloendopeptidase of Bacillus intermedius (MprBi) was purified from the culture medium of a recombinant strain of Bacillus subtilis. The amino acid sequence of the homogeneous protein was determined using MALDI-TOF mass spectrometry. The sequence of the first ten residues from the N-terminus of the mature protein is ASTGSQKVTV. Physicochemical properties of the enzyme and its substrate specificity have been studied. The molecular weight of the metalloproteinase constitutes 19 kDa, the K m and k cat values are 0.06 mM and 1210 sec-1, respectively, and the pI value is 5.4. The effect of different inhibitors and metal ions on the enzyme activity has been studied. Based on the analysis of the amino acid sequence of the active site motif and the Met-turn together with the enzyme characteristics, the novel bacterial metalloproteinase MprBi is identified as a metzincin clan adamalysin/reprolysin-like metalloprotease. © 2010 Pleiades Publishing, Ltd

Quantum Field Theory: Where We Are

We comment on the present status, the concepts and their limitations, and the successes and open problems of the various approaches to a relativistic quantum theory of elementary particles, with a hindsight to questions concerning quantum gravity and string theory.Comment: To appear in: An Assessment of Current Paradigms in the Physics of Fundamental Phenomena, to be published by Springer Verlag (2006

Isolation and characteristics of Bacillus intermedius glutamyl endopeptidase secreted by a recombinant strain of Bacillus subtilis at various growth phases

The recombinant strain of Bacillus subtilis bearing B. intermedius glutamyl endopeptidase gene in multicopy plasmid Δ58.21 secretes the enzyme to the medium at the phase of slowing of growth and the stationary growth phase with accumulation maxima at 24 and 48 h. Enzyme samples were isolated from the culture liquid after 24 and 48 h of culturing of and were purified up to homogeneity by ion exchange chromatography on carboxymethyl cellulose and HPLC on a MonoS column. The molecular weight of the corresponding proteins was 29 kDa. Both preparations had identical structure, but differed in affinity to the specific substrate Z-Glu-pNA. The effects of Ca2+ ions and specific low-molecular and protein inhibitors on the activity of the enzyme corresponding to various growth phases has been studied. © 2008 MAIK Nauka

Vector like gauge theories with almost massless fermions on the lattice

A truncation of the overlap (domain wall fermions) is studied and a criterion for reliability of the approximation is obtained by comparison to the exact overlap formula describing massless quarks. We also present a truncated version of regularized, pure gauge, supersymmetric models. The mechanism for generating almost masslessness is shown to be a generalized see-saw which can also be viewed as a version of Froggatt-Nielsen's method for obtaining natural large mass hierarchies. Viewed in this way the mechanism preserving the mass hierarchy naturally avoids preserving even approximately axial U(1). The new insights into the source of the mass hierarchy suggest ways to increase the efficiency of numerical simulations of QCD employing the truncated overlap.Comment: 35 pages, TeX, 4 figures using eps