Remarks on (1−q)(1-q) expansion and factorization approximation in the Tsallis nonextensive statistical mechanics

The validity of (1-q) expansion and factorization approximations are analysed in the framework of Tsallis statistics. We employ exact expressions for classical independent systems (harmonic oscillators) by considering the unnormalized and normalized constrainsts. We show that these approxiamtions can not be accurate in the analysis of systems with many degrees of freedom.Comment: Latex, 6 pages, 2 figure

Open su(4)-invariant spin ladder with boundary defects

The integrable su(4)-invariant spin-ladder model with boundary defect is studied using the Bethe ansatz method. The exact phase diagram for the ground state is given and the boundary quantum critical behavior is discussed. It consists of a gapped phase in which the rungs of the ladder form singlet states and a gapless Luttinger liquid phase. It is found that in the gapped phase the boundary bound state corresponds to an unscreened local moment, while in the Luttinger liquid phase the local moment is screened at low temperatures in analogy to the Kondo effect.Comment: Revtex 9 pages, published in PR

GRUNDTVIG: Trends in der Antragsrunde 2009

A good two-and-a-half years after the EU's lifelong learning education programme began, the German National Agency has drawn up an interim balance and reflects current trends of the 2009 applications in the programme. GRUNDTVIG for general adult education. There is increasing demand for established forms of funding, affecting both learning partnerships and continuing education funding for individual workers in the field. Since 2009 the EU has put forward various new funding programmes. There has been great demand for bilateral exchanges on voluntary projects for older people, as well as for more informal visits and exchanges, while more long-term periods abroad (assistantships drive) have got off to a weaker start. The workshops drive has received a warm reception in Germany; however, looking outside Germany it can be seen that demand has varied greatly across European countries.Gut zweieinhalb Jahre nach dem Start des EU-Bildungsprogramms für lebenslanges Lernen zieht die Nationale Agentur für Deutschland eine Zwischenbilanz und reflektiert aktuelle Trends bei den Antragstellungen 2009 im Programm GRUNDTVIG für die allgemeine Erwachsenenbildung. Etablierte Förderformen werden verstärkt nachgefragt; das gilt für Lernpartnerschaften wie auch für die Förderungen der individuellen Fortbildung für Beschäftigte im Feld. Seit 2009 werden seitens der EU verschiedene neue Förderaktionen angeboten. Während der bilaterale Austausch im Rahmen von Freiwilligenprojekte für ältere Menschen sowie eher informelle Besuche und Austausche eine starke Nachfrage verzeichnen, sind längerfristige Auslandsaufenthalte (Aktion Assistent/inn/en) schwächer gestartet. Die Aktion Workshops ist in Deutschland gut angenommen worden; der Blick über die Grenze zeigt aber, dass die Nachfrage in den Ländern Europas sehr unterschiedlich ausfällt

Path Integral Approach to the Nonextensive Canonical Density Matrix

Feynman's path integral is herein generalized to the nonextensive canonical density matrix based on Tsallis entropy. This generalization is done in two ways by using unnormalized and normalized constraints. Firstly, we consider the path integral formulation with unnormalized constraints, and this generalization is worked out through two different ways, which are shown to be equivalent. These formulations with unnormalized constraints are solutions to two generalized Bloch equations proposed in this work. The first form of the generalized Bloch equation is linear, but with a temperature-dependent effective Hamiltonian; the second form is nonlinear and resembles the anomalous correlated diffusion equation (porous medium equation). Furthermore, we can extend these results to the prescription of field theory using integral representations. The second development is dedicated to analyzing the path integral formulation with normalized constraints. To illustrate the methods introduced here, we analyze the free particle case and a non-interacting scalar field. The results herein obtained are expected to be useful in the discussion of generic nonextensive contexts.Comment: (Univ. Est. de Maringa, PR- Brazil),17 pages, Late

Alginate Composition Effects on a Neural Stem Cell-Seeded Scaffold

The purpose of this study was to evaluate the effects of alginate composition on the neurotrophic factor release, viability, and proliferation of encapsulated neural stem cells (NSCs), as well as on the mechanical stability of the scaffold itself. Four compositions were tested: a high guluronic acid (68%) and a high mannuronic acid (54%) content alginate, with or without a poly-L-lysine (PLL) coating layer. Enzyme-linked immunosorbent assay was used to quantify the release of brain-derived neurotrophic factor, glial-derived neurotrophic factor, and nerve growth factor from the encapsulated cells. All three factors were detected from encapsulated cells only when a high L-guluronic acid alginate without PLL was used. Additionally, capsules with this composition remained intact more frequently when exposed to solutions of low osmolarity, potentially indicating superior mechanical stability. Alginate beads with a PLL-coated, high D-mannuronic acid composition were the most prone to breakage in the osmotic pressure test, and were too fragile for histology and proliferation assays after 1 week in vitro. NSCs survived and proliferated in the three remaining alginate compositions similarly over the 21-day study course irrespective of scaffold condition. NSC-seeded alginate beads with a high L-guluronic acid, non-PLL-coated composition may be useful in the repair of injured nervous tissue, where the mechanism is the secretion of neuroprotective factors. We verify the neuroprotective effects of medium conditioned by NSC-seeded alginate beads on the serum withdrawal-mediated death of PC-12 cells here.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78133/1/ten.tec.2008.0302.pd

A microsatellite marker for yellow rust resistance in wheat

Bulk segregant analysis (BSA) was used to identify molecular markers associated with yellow rust disease resistance in wheat (Triticum aestivum L.). DNAs isolated from the selected yellow rust tolerant and susceptible F-2 individuals derived from a cross between yellow rust resistant and susceptible wheat genotypes were used to established a "tolerant" and a "susceptible" DNA pool. The BSA was then performed on these DNA pools using 230 markers that were previously mapped onto the individual wheat chromosomes. One of the SSR markers (Xgwm382) located on chromosome group 2 (A, B, D genomes) was present in the resistant parent and the resistant bulk but not in the susceptible parent and the susceptible bulk, suggesting that this marker is linked to a yellow rust resistance gene. The presence of Xgwm382 was also tested in 108 additional wheat genotypes differing in yellow rust resistance. This analysis showed that 81% of the wheat genotypes known to be yellow rust resistant had the Xgwm382 marker, further suggesting that the presence of this marker correlates with yellow rust resistance in diverse wheat germplasm. Therefore, Xgwm382 could be useful for marker assisted selection of yellow rust resistances genotypes in wheat breeding programs

Can Barrier to Relative Sliding of Carbon Nanotube Walls Be Measured?

Interwall interaction energies, as well as barriers to relative sliding of the walls along the nanotube axis, are first calculated for pairs of both armchair or both zigzag adjacent walls of carbon nanotubes with a wide range of radiuses. It is found that for the pairs with the radius of the outer wall greater than 5 nm both the interwall interaction energy and barriers to the relative sliding per one atom of the outer wall only slightly depends on the wall radius. A wide set of the measurable physical quantities determined by these barriers are estimated as a function of the wall radius: shear strengths and diffusion coefficients for relative sliding of the walls along the axis, as well as frequencies of relative axial oscillations of the walls. For nonreversible telescopic extension of the walls, maximum overlap of the walls for which threshold static friction forces are greater than capillary forces is estimated. Possibility of experimental verification of the calculated barriers by measurements of the estimated physical quantities is discussed.Comment: 16 pages, 8 figure

Erbium-doped ion-exchanged waveguide lasers in BK-7 glass

Ion exchange in glass is a simple, flexible, technique to realize optical fiber compatible planar waveguide devices. Recently, neodymium-doped waveguide lasers operating at 1060 and 1300 nm have been demonstrated in this technology. Lasers operating at 1540 nm are desirable for telecommunication applications and we report here, for the first time, ion-exchanged waveguide lasers in erbium-doped glass emitting at this wavelength. Lasers in BK-7 glass doped with 0.5 wt% Er2O3 and pumped at 980 nm exhibited launched pump power thresholds of 150 mW and slope efficiencies of 0.55%. The waveguides operated in a single transverse mode at the lasing wavelength