4,101 research outputs found
On Witten multiple zeta-functions associated with semisimple Lie algebras IV
In our previous work, we established the theory of multi-variable Witten
zeta-functions, which are called the zeta-functions of root systems. We have
already considered the cases of types , , , and . In
this paper, we consider the case of -type. We define certain analogues of
Bernoulli polynomials of -type and study the generating functions of them
to determine the coefficients of Witten's volume formulas of -type. Next
we consider the meromorphic continuation of the zeta-function of -type and
determine its possible singularities. Finally, by using our previous method, we
give explicit functional relations for them which include Witten's volume
formulas.Comment: 22 pag
The peroxisomal membrane protein Pex14p of Hansenula polymorpha is phosphorylated in vivo
Hansenula polymorpha Pex14p (HpPex14p) is a component of the peroxisomal membrane essential for peroxisome biogenesis, Here, we show that HpPex14p is phosphorylated in vivo. In wild-type H, polymorpha cells, grown in the presence of [P-32]orthophosphate, the 32P label was incorporated into HpPex14p. Labelled HpPex14p was induced after a shift of cells to methanol-containing media and rapidly disappeared after a shift to glucose medium, which induces specific peroxisome degradation. Alkaline phosphatase treatment of labelled HpPex14p resulted in the release of 32P and a minor shift of the HpPex14p band on Western blots. Phosphoamino acid analysis by two dimensional silica gel thin layer chromatography suggested that the major phosphoamino acid in phosphorylated HpPex14p was acid-labile, (C) 1999 Federation of European Biochemical Societies
Memory and rejuvenation in a spin glass
The temperature dependence of the magnetisation of a Cu(Mn) spin glass (
57 K) has been investigated using weak probing magnetic fields ( =
0.5 or 0 Oe) and specific thermal protocols. The behaviour of the zero-field
cooled, thermoremanent and isothermal remanent magnetisation on (re-)cooling
the system from a temperature (40 K) where the system has been aged is
investigated. It is observed that the measured magnetisation is formed by two
parts: (i) a temperature- and observation time-dependent thermally activated
relaxational part governed by the age- and temperature-dependent response
function and the (latest) field change made at a lower temperature, superposed
on (ii) a weakly temperature-dependent frozen-in part. Interestingly we observe
that the spin configuration that is imprinted during an elongated halt in the
cooling, if it is accompanied by a field induced magnetisation, also includes a
unidirectional excess magnetisation that is recovered on returning to the
ageing temperature.Comment: EPL style; 7 pages, 5 figure
Produção orgânica de café no Sítio Santa Cecília, em Glória de Dourados-MS
bitstream/item/66258/1/31284.pdfOrganizado por: Alberto Feiden, Milton Parron Padovan, Adalgiza Inês Campolim, Aurélio Vinícius Borsato, Ivo de Sá Motta, João Batista Catto, Tércio Jacques Fehlauer
Temperature Chaos, Rejuvenation and Memory in Migdal-Kadanoff Spin Glasses
We use simulations within the Migdal-Kadanoff real space renormalization
approach to probe the scales relevant for rejuvenation and memory in spin
glasses. One of the central questions concerns the role of temperature chaos.
First we investigate scaling laws of equilibrium temperature chaos, finding
super-exponential decay of correlations but no chaos for the total free energy.
Then we perform out of equilibrium simulations that follow experimental
protocols. We find that: (1) rejuvenation arises at a length scale smaller than
the ``overlap length'' l(T,T'); (2) memory survives even if equilibration goes
out to length scales much larger than l(T,T').Comment: 4 pages, 4 figures, added references, slightly changed content,
modified Fig.
Participation of Cbfa1 in regulation of chondrocyte maturation
AbstractObjective Cbfa1 is a transcription factor, which is classified into the runt family. The mice lacking this gene display complete loss of bone formation, indicating that Cbfa1 is an essential factor for osteoblast differentiation. The Cbfa1-deficient mice also show an abnormality in cartilage development. Although cartilage anlagens are well formed in these mice, endochondral ossification is blocked, and most of chondrocytes fail to differentiate into their maturation form as characterized by the absence of type X collagen and low levels of alkaline phosphatase activity. It is suggested that Cbfa1 may participate in chondrocyte differentiation. In this study, we have investigated the role of Cbfa1 in chondrocytes during their cytodifferentiation in vitro.Design To investigate the role of Cbfa1 in regulation of chondrocyte differentiation, we over-expressed Cbfa1 or its dominant negative form in cultured chick chondrocytes using a retrovirus (RCAS)system and examined changes in chondrocyte behaviour induced by the introduced genes.Results Mature chondrocytes isolated form the cephalic portion of sterna seemed to express Cbfa1 more prominently than immature chondrocytes isolated from the one-third caudal portion of sterna. Over-expression of Cbfa1 in immature chondrocytes strongly stimulated alkaline phosphatase activity and matrix calcification. In contrast, expression of a dominant negative form of Cbfa1, which lacks the C-terminal PST domain, severely inhibited alkaline phosphatase activity and matrix calcification in mature chondrocytes.Conclusion Taken together with the observation that Cbfa1 transcripts dominantly localized in hypertrophic chondrocytes as well as in osteoblasts, it is suggested that Cbfa1 plays an important role in the progression of chondrocyte maturation
Real space application of the mean-field description of spin glass dynamics
The out of equilibrium dynamics of finite dimensional spin glasses is
considered from a point of view going beyond the standard `mean-field theory'
versus `droplet picture' debate of the last decades. The main predictions of
both theories concerning the spin glass dynamics are discussed. It is shown, in
particular, that predictions originating from mean-field ideas concerning the
violations of the fluctuation-dissipation theorem apply quantitatively,
provided one properly takes into account the role of the spin glass coherence
length which plays a central role in the droplet picture. Dynamics in a uniform
magnetic field is also briefly discussed.Comment: 4 pages, 4 eps figures. v2: published versio
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