304 research outputs found
Exponential mapping for non semisimple quantum groups
The concept of universal T matrix, recently introduced by Fronsdal and
Galindo in the framework of quantum groups, is here discussed as a
generalization of the exponential mapping. New examples related to
inhomogeneous quantum groups of physical interest are developed, the duality
calculations are explicitly presented and it is found that in some cases the
universal T matrix, like for Lie groups, is expressed in terms of usual
exponential series.Comment: 12 page
Effect of recombinant TRAIL in a murine co-culture system of osteoclastogenesis
Although some experimental evidence has implicated the TRAIL/TRAIL-receptor system in the regulation of osteoclastogenesis, the only available studies performed so far have been performed on isolated pre-osteoclasts, induced to differentiate by the addition of recombinant RANKL and M-CSF. Using a more physiological co-culture system in the absence of exogenous cytokines, we have here demonstrated that recombinant TRAIL inhibits osteoclast formation, but only at relatively high concentrations (500 ng/mL)
On a nonstandard two-parametric quantum algebra and its connections with and
A quantum algebra associated with a nonstandard
-matrix with two deformation parameters is studied and, in
particular, its universal -matrix is derived using Reshetikhin's
method. Explicit construction of the -dependent nonstandard -matrix
is obtained through a coloured generalized boson realization of the universal
-matrix of the standard corresponding to a
nongeneric case. General finite dimensional coloured representation of the
universal -matrix of is also derived. This
representation, in nongeneric cases, becomes a source for various
-dependent nonstandard -matrices. Superization of leads to the super-Hopf algebra . A contraction
procedure then yields a -deformed super-Heisenberg algebra
and its universal -matrix.Comment: 17pages, LaTeX, Preprint No. imsc-94/43 Revised version: A note added
at the end of the paper correcting and clarifying the bibliograph
Graded Contractions of Affine Kac-Moody Algebras
The method of graded contractions, based on the preservation of the
automorphisms of finite order, is applied to the affine Kac-Moody algebras and
their representations, to yield a new class of infinite dimensional Lie
algebras and representations. After the introduction of the horizontal and
vertical gradings, and the algorithm to find the horizontal toroidal gradings,
I discuss some general properties of the graded contractions, and compare them
with the In\"on\"u-Wigner contractions. The example of is discussed
in detail.Comment: 23 pages, Ams-Te
Coherent and squeezed states of quantum Heisenberg algebras
Starting from deformed quantum Heisenberg Lie algebras some realizations are
given in terms of the usual creation and annihilation operators of the standard
harmonic oscillator. Then the associated algebra eigenstates are computed and
give rise to new classes of deformed coherent and squeezed states. They are
parametrized by deformed algebra parameters and suitable redefinitions of them
as paragrassmann numbers. Some properties of these deformed states also are
analyzed.Comment: 32 pages, 3 figure
Universal --matrices for non-standard (1+1) quantum groups
A universal quasitriangular --matrix for the non-standard quantum (1+1)
Poincar\'e algebra is deduced by imposing analyticity in the
deformation parameter . A family of ``quantum graded contractions"
of the algebra is obtained; this set of
quantum algebras contains as Hopf subalgebras with two primitive translations
quantum analogues of the two dimensional Euclidean, Poincar\'e and Galilei
algebras enlarged with dilations. Universal --matrices
for these quantum Weyl algebras and their associated quantum groups are
constructed.Comment: 12 pages, LaTeX
Fine tuning of protein kinase C (PKC) isoforms in cancer: shortening the distance from the laboratory to the bedside
Activation of PKC-Δ counteracts maturation and apoptosis of HL-60 myeloid leukemic cells in response to TNF family members
Protein kinase C (PKC)-Δ, a component of the serine/threo-nine PKC family, has been shown to influence the survival and differentiation pathways of normal hematopoietic cells. Here, we have modulated the activity of PKC-Δ with specific small molecule activator or inhibitor peptides. PKC-Δ inhibitor and activator peptides showed modest effects on HL-60 maturation when added alone, but PKC-Δ activator peptide significantly counteracted the pro-maturative activity of tumor necrosis factor (TNF)-α towards the monocytic/macrophagic lineage, as evaluated in terms of CD14 surface expression and morphological analyses. Moreover, while PKC-Δ inhibitor peptide showed a reproducible increase of TNF-related apoptosis inducing ligand (TRAIL)-induced apoptosis, PKC-Δ activator peptide potently counteracted the pro-apoptotic activity of TRAIL. Taken together, the anti-maturative and anti-apoptotic activities of PKC-Δ envision a potentially important proleukemic role of this PKC family member
Quantum limit of deterministic theories
We show that the quantum linear harmonic oscillator can be obtained in the
large limit of a classical deterministic system with SU(1,1) dynamical
symmetry. This is done in analogy with recent work by G.'t Hooft who
investigated a deterministic system based on SU(2). Among the advantages of our
model based on a non--compact group is the fact that the ground state energy is
uniquely fixed by the choice of the representation.Comment: 4 pages, 2 figures, minor corrections added. To appear in the
Proceedings of Waseda International Symposium on Fundamental Physics: "New
Perspectives in Quantum Physics", 12-15 November 2002, Waseda University,
Tokyo, Japa
Avaliação simultùnea das membranas plasmåtica, acrossomal e mitocondrial de espermatozoides de carneiros por sondas fluorescentes
Neste experimento, foi definida uma combinação de sondas fluorescentes: iodeto de propĂdio (PI), aglutinina de Pisum sativum conjugada ao isotiocionato de fluoresceĂna (FITC-PSA) e JC-1. Para esta proposta, quatro ejaculados de trĂȘs carneiros (n=12), que apresentavam motilidade >80% e alteraçÔes morfolĂłgicas <10%, foram diluĂdos em meio TALP e divididos em duas alĂquotas. Uma alĂquota foi submetida a trĂȘs ciclos de flash frozen e descongelação, para induzir danos nas membranas celulares e distĂșrbios na função mitocondrial. TrĂȘs tratamentos foram preparados com as seguintes proporçÔes preestabelecidas de sĂȘmen fresco: sĂȘmen submetido a flash frozen: 0:100 (T0), 50:50 (T50) e 100:0 (T100). As amostras foram coradas no protocolo proposto e avaliadas por microscopia de epifluorescĂȘncia. Para integridade de membrana plasmĂĄtica, detectada pela sonda PI, foi obtida a equação: v=1,09+0,86X (R2=0,98). O acrossomo intacto, verificado pela sonda FITC-PSA, produziu a equação: v=2,76+0,92X (R2=0,98). O alto potencial de membrana mitocondrial, marcada em vermelho-alaranjado pelo JC-1, foi estimado pela equação: v=1,90+0,90X (R2=0,98). As equaçÔes lineares resultantes demonstraram que a tĂ©cnica Ă© eficiente e prĂĄtica para avaliação simultĂąnea das membranas plasmĂĄtica, acrossomal e mitocondrial em espermatozoides de carneirosIn this experiment, it was defined a protocol of fluorescent probes combination: propidium iodide (PI), fluorescein isothiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA), and JC-1. For this purpose, four ejaculates from three different rams (n=12), all showing motility ïł80% and abnormal morphology ïŁ10%, were diluted in TALP medium and split into two aliquots. One of the aliquots was flash frozen and thawed in three continuous cycles, to induce damage in cellular membranes and to disturb mitochondrial function. Three treatments were prepared with the following fixed ratios of fresh semen:flash frozen semen: 0:100 (T0), 50:50 (T50), and 100:0 (T100). Samples were stained in the proposal protocol and evaluated by epifluorescence microscopy. For plasmatic membrane integrity, detected by PI probe, it was obtained the equation: ƶ=1.09+0.86X (R2=0.98). The intact acrosome, verified by the FITC-PSA probe, produced the equation: ƶ=2.76+0.92X (R2=0.98). The high mitochondrial membrane potential, marked in red-orange by JC-1, was estimated by the equation: ƶ=1.90+0.90X (R2=0.98). The resulting linear equations demonstrate that this technique is efficient and practical for the simultaneous evaluations of the plasmatic, acrosomal, and mitochondrial membranes in ram spermatozoa.FAPESP 00/14653-6 e 01/13940-
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