Showing papers by "University of Luxembourg published in 2001"
TL;DR: A possible relationship between transient exposure to endocrine disrupters and sexual precocity is suggested, and deserves further studies in immigrant children with non-advanced puberty.
Abstract: In a retrospective auxological study of 145 patients seen in Belgium during a 9-year period for treatment of precocious puberty, 28% appeared to be foreign children (39 girls, one boy) who immigrated 4 to 5 years earlier from 22 developing countries, without any link to a particular ethnic or country background. The patients were either adopted (n = 28) or non-adopted (n = 12), the latter having normal weight and height at immigration and starting early puberty without evidence of earlier deprivation. This led to the hypothesis that the mechanism of precocious puberty might involve previous exposure to oestrogenic endocrine disrupters. A toxicological plasma screening for eight pesticides detected p,p'-DDE, which is derived from the organochlorine pesticide DDT. Median p,p'-DDE concentrations were respectively 1.20 and 1.04 ng/ml in foreign adopted (n = 15) and non-adopted (n = 11) girls with precocious puberty, while 13 out of 15 Belgian native girls with idiopathic or organic precocious puberty showed undetectable concentrations (<0.1 ng/ml). A possible relationship between transient exposure to endocrine disrupters and sexual precocity is suggested, and deserves further studies in immigrant children with non-advanced puberty.
259 citations
TL;DR: The evidence suggests abnormal STAT signaling and growth regulation in Hodgkin cell lines.
209 citations
TL;DR: The phenotype of the A30P mutation in the SNCA gene is similar to that of sporadic IPD, including a high variability of the age at disease onset, ranging from 54 to 76 years.
Abstract: Background: The authors identified the second known mutation in the α-synuclein(SNCA) gene, an alanine-to-proline exchange in amino acid position 30 (A30P), that cosegregates with the disease in one German family with autosomal dominantly inherited parkinsonism (ADP). The authors studied carriers of the A30P mutation to compare the phenotype of this mutation with idiopathic PD (IPD) and to assess nigrostriatal dopaminergic function in symptomatic and preclinical mutation carriers. Methods: The pedigree of the A30P family spans five generations with five affected individuals. The authors performed detailed neurologic examinations followed by mutation analysis in 11 living individuals. In three mutation carriers, two individuals with definite PD and one person at risk for PD, they used l-[18]F-fluoro-3,4-dihydroxyphenylalanine (F-DOPA), [11]C-raclopride (RAC), and [18]F-fluorodeoxyglucose (FDG) PET to investigate presynaptic dopaminergic function, dopamine D2 receptors, and cerebral energy metabolism. The authors studied the cognitive functions of carriers of the A30P mutation using neuropsychological screening. Results: PET studies revealed striatal presynaptic dopaminergic alterations consistent with sporadic IPD in two affected family members and no evidence for nigrostriatal dopaminergic dysfunction in one presymptomatic mutation carrier. Neuropsychological testing in four mutation carriers provided evidence for cognitive impairment as a frequent and early symptom of the A30P mutation; this is also supported by regional cerebral energy metabolism alterations in the clinically presymptomatic subject. Conclusions: The phenotype of the A30P mutation in the SNCA gene is similar to that of sporadic IPD, including a high variability of the age at disease onset, ranging from 54 to 76 years. The follow-up of presymptomatic carriers of the A30P mutation may give insight into preclinical disease stages and early manifestations of PD.
154 citations
01 Jan 2001
115 citations
TL;DR: In this paper, the authors give a complete identification of the deformation quantization which was obtained from the Berezin-Toeplitz quantization on an arbitrary compact Kahler manifold.
Abstract: We give a complete identification of the deformation quantization which was obtained from the Berezin- Toeplitz quantization on an arbitrary compact Kahler manifold. The deformation quantization with the opposite star-product proves to be a differential deformation quantization with separation of variables whose dassifying form is explicitly calculated. Its characteristic dass (which dassifies star-products up to equivalence) is obtained. The proof is based on the microlocal description of the Szego kernel of a strictly pseudoconvex domain given by Boutet de Monvel and Sjostrand.
105 citations
TL;DR: The functional mechanism of NF-kappaB inhibition in the myocardium by estrogen receptors-alpha and -beta is analyzed and it is found that addition of either estrogen receptor-alpha or estrogen receptor -beta as recombinant protein was sufficient to inhibit staurosporine-dependent p65/p50 DNA binding in cardiac myocytes.
89 citations
TL;DR: This paper used martingale methods to give Bismut type derivative formulas for differentials and co-differentials of heat semigroups on forms, and more generally for sections of vector bundles.
83 citations
01 Jan 2001
TL;DR: The history, theory, and application of symplectic reduction have been discussed in this paper, where the Mumford quotient and the Yang-Mills measure have been applied to the analysis of geometric operator on open manifolds.
Abstract: Some comments on the history, theory, and applicationsof symplectic reduction- Homology of complete symbols and non-commutative geometry- Cohomology of the Mumford quotient- Poisson sigma models and symplectic groupoids- Pseudo-differential operators and deformation quantization- Singularities and Poisson geometry of certainrepresentation spaces- Quantized reduction as a tensor product- Analysis of geometric operator on open manifolds: a groupoid approach- Smooth structures on stratified spaces- Singular projective varieties and quantization- Poisson structure and quantization of Chern-Simons theory- Combinatorial quantization of Euclidean gravityin three dimensions- The Yang-Mills measure and symplectic structureover spaces of connections
60 citations
Posted Content•
TL;DR: In this paper, complete existence and uniqueness results for local 2-cocycles defining almost-graded central extensions of the functions algebra, the vector field algebra, and the differential operator algebra are shown.
Abstract: Multi-point algebras of Krichever Novikov type for higher genus Riemann surfaces are generalisations of the Virasoro algebra and its related algebras. Complete existence and uniqueness results for local 2-cocycles defining almost-graded central extensions of the functions algebra, the vector field algebra, and the differential operator algebra (of degree \le 1) are shown. This is applied to the higher genus, multi-point affine algebras to obtain uniqueness for almost-graded central extensions of the current algebra of a simple finite-dimensional Lie algebra. An earlier conjecture of the author concerning the central extension of the differential operator algebra induced by the semi-infinite wedge representations is proved.
52 citations
Posted Content•
TL;DR: In this article, the authors develop an argument explaining why retail prices may rise in response to the deregulation of opening hours, and they make this point in a model of imperfect duopolistic competition.
Abstract: This Paper develops an argument explaining why retail prices may rise in response to the deregulation of opening hours. We make this point in a model of imperfect duopolistic competition. In a deregulated market retailers view the choice of opening hours as a means to increase the degree of perceived product differentiation thus relaxing price competition. If the opportunity costs of the time spent on shopping are sufficiently high the equilibrium configuration has asymmetric shopping hours where one retailer stays open for longer than the other does. Both retailers charge higher prices than under regulation, and both are strictly better off.
TL;DR: In this article, a trade union whose purpose is to raise wages above the competitive level may foster economic growth if it succeeds in shifting income away from the owners of capital to the workers and if the workers' marginal propensity to save exceeds the one of capitalists.
Abstract: A trade union whose purpose is to raise wages above the competitive level may foster economic growth if it succeeds in shifting income away from the owners of capital to the workers and if the workers' marginal propensity to save exceeds the one of capitalists. We make this point in an overlapping generations framework with unionized labor. Considering a monopoly union which cares for wages and employment, we determine a range of trade union objectives and characterize the aggregate technology so that the union's policy spurs per capita income growth and increases welfare of all generations that adhere to the union.
TL;DR: With the successful direct visualization of functional alphaIIb(beta3) receptors in living cells, the generation of autofluorescent integrins in transgenic animals will become possible, allowing new approaches to study the dynamics of integrin functions.
Abstract: Using green fluorescent protein (GFP) as an autofluorescent tag, we report the first successful visualization of a beta3 integrin in a living cell. GFP fused in frame to the cytoplasmic tail of either alphaIIb or beta3 allowed normal expression, heterodimerization, processing and surface exposure of alphaIIbGFPbeta3 and alphaIIb(beta3)GFP receptors in Chinese hamster ovary (CHO) cells. Direct microscopic observation of the autofluorescent cells in suspension following antibody-induced alphaIIb(beta3) capping revealed an intense autofluorescent cap corresponding to unlabelled immunoclustered GFP-tagged alphaIIb(beta3). GFP-tagged alphaIIbbeta3 receptors mediated fibrinogen-dependent cell adhesion, were readily detectable in focal adhesions of unstained living cells and triggered p125(FAK) tyrosine phosphorylation similar to wild-type alphaIIb(beta3) (where FAK corresponds to focal adhesion kinase). However, GFP tagged to beta3, but not to alphaIIb, induced spontaneous CHO cell aggregation in the presence of soluble fibrinogen, as well as binding of the fibrinogen mimetic monoclonal antibody PAC1 in the absence of alphaIIb(beta3) receptor activation. Time-lapse imaging of living transfectants revealed a characteristic redistribution of GFP-tagged alphaIIb(beta3) during the early stages of cell attachment and spreading, starting with alphaIIb(beta3) clustering at the rim of the cell contact area, that gradually overlapped with the boundary of the attached cell, and, with the onset of cell spreading, to a reorganization of alphaIIb(beta3) in focal adhesions. Taken together, our results demonstrate that (1) fusion of GFP to the cytoplasmic tail of either alphaIIb or beta3 integrin subunits allows normal cell surface expression of a functional receptor, and (2) structural modification of the beta3 integrin cytoplasmic tail, rather than the alphaIIb subunit, plays a major role in alphaIIb(beta3) affinity modulation. With the successful direct visualization of functional alphaIIb(beta3) receptors in living cells, the generation of autofluorescent integrins in transgenic animals will become possible, allowing new approaches to study the dynamics of integrin functions.
TL;DR: Data indicate that nociceptin-induced mechanosensitivity changes in the rat knee depend upon NK1 receptor activation possibly through secondary release of substance P.
Abstract: Nociceptin is known to act peripherally in the rat knee joint to modulate articular mechanosensitivity and it has been postulated that neurokinin-1 (NK1) receptors may be involved in this process. To test this hypothesis, single unit extracellular recordings were made from knee joint primary afferents in response to normal and extreme rotation of the joint. Afferent firing rate was assessed following close intraarterial injection of the NK1 antagonist RP67580 followed by administration of 20 nmol nociceptin. With both normal and hyper-rotation of the knee, nociceptin was unable to elicit its usual mechanomodulatory effect such that afferent activity was not significantly different from control (P=0.7572 and P=0.9182 for normal and hyper-rotation of the joint, respectively). These data indicate that nociceptin-induced mechanosensitivity changes in the rat knee depend upon NK1 receptor activation possibly through secondary release of substance P.
01 Apr 2001
TL;DR: In this article, the existence of the Berezin-Toeplitz deformation quantization of arbitrary compact quantizable Kahler manifolds is discussed and the results on the asymptotic expansion of the Fubini-Study fundamental form under coherent state embedding are presented.
Abstract: In this lecture results on the Berezin-Toeplitz quantization of arbitrary compact quantizable Kahler manifolds are presented. These results are obtained in joint work with M. Bordemann and E. Meinrenken. The existence of the Berezin-Toeplitz deformation quantization is also covered. Recent results obtained in joint work with A. Karabegov on the asymptotic expansion of the Berezin transform for arbitrary quantizable compact Kahler manifolds are explained. As an application the asymptotic expansion of the Fubini-Study fundamental form under the coherent state embedding is considered. Some comments on the dynamics of the quantum operators are given. (This is an extended write-up of an invited lecture presented at the workshop "Asymptotic properties of time evolutions in classical and quantum systems", September 13-17, 1999, Bologna, Italy.)
TL;DR: In this article, the authors link the old literature on employment subsidies with the current theories of contract and regulation, and identify the asymmetry of information between the government and the private firm as the source of these problems.
TL;DR: The data suggest that resistance of advanced melanoma cells to interleukin-6 is associated with reduced inhibition of cyclin-dependent kinase 2, which appears to be a consequence of a complex alteration inInterleuk in-6 signal transduction.
07 Oct 2001
TL;DR: An algorithm for removing users from a congested system, in order to avoid outage is proposed and evaluated and results show that the proposed algorithm gives substantial increase of the system performance compared to random removal of users.
Abstract: We investigate the use of joint optimal downlink beamforming, power control and access point allocation, in a multicell SDMA system. Smart antennas are used at the access points and single antennas are used at the terminals. The possibility to send messages to multiple terminals on the same frequency in the same time slot is exploited. An algorithm for removing users from a congested system, in order to avoid outage is proposed and evaluated Results show that the proposed algorithm gives substantial increase of the system performance compared to random removal of users.
TL;DR: In this paper, it was shown that free international trade leads to an increase of the de facto elasticity of substitution between the domestic factors of production, and that such an increase in the elasticity influences the steady state and the speed of convergence.
Abstract: This paper unites elements of Sidrauski's (1967) monetary model of growth, Ventura's (1997) analysis of the effects of international trade on growth, and some work on the labour market implications of growth by Barro and Sala-i-Martin (1995). It was shown by Ventura that, for a small economy, free international trade leads to an increase of the de facto elasticity of substitution between the domestic factors of production. The first part of the paper analyses how such an increase in the elasticity of substitution influences the steady state and the speed of convergence. From the Sidrauski model we know that money is super-neutral in the long-run but that monetary policy can have real effects along the transition path as long as the intertemporal elasticity of substitution is not equal to one. In the second part of this paper, it is shown how these results also depend on the elasticity of substitution between factors of production. The results give some important insights into possible interactions between...
01 Jan 2001
Journal Article•
01 Jan 2001
Journal Article•
TL;DR: This database contains a large number of invariant rings of finite groups, mostly in the modular case, and gives information on generators and structural properties of the invariants.
Abstract: We announce the creation of a database of invariant rings. This database contains a large number of invariant rings of finite groups, mostly in the modular case. It gives information on generators and structural properties of the invariant rings. The main purpose is to provide a tool for researchers in invariant theory.
Journal Article•
01 Jan 2001