People on both sides of the aegean sea

International audienceOur contribution is devoted to a constructive overview over the implicit system approach in modern control of switched dynamic models. We study a class of non-stationary autonomous switched systems and formally establish the existence of solution. We next incorporate the implicit systems approach into our consideration. At the beginning of the contribution we also develop a specific system example that is used for illustrations of various system aspects that we consider. Our research involves among others a deep examination of the reachability property in the framework of the implicit system framework that we propose. Based on this methodology we finally propose a resulting robust control design for the switched systems under consideration and the proposed control strategy is implemented in the context of the illustrative example

The effect of high-tech services offshoring on skilled employment: intra-firm evidence

The offshoring of high-tech services has greatly increased in recent years, with consequences for firms demand for skilled employment in firms. This paper specifically analyzes the relationship between R&D offshoring and the demand for R&D employment using firm-level data for Spanish manufacturing and services companies during the period 2004-2009. Estimating different specifications with panel data techniques, we find that this association is statistically positive. In particular, for services firms a 1 percentage point increase in R&D offshoring raises the demand for researchers by about 11%. This suggests the existence of complementarity among them as productive inputs

Bayesian Semiparametric Multi-State Models

Multi-state models provide a unified framework for the description of the evolution of discrete phenomena in continuous time. One particular example are Markov processes which can be characterised by a set of time-constant transition intensities between the states. In this paper, we will extend such parametric approaches to semiparametric models with flexible transition intensities based on Bayesian versions of penalised splines. The transition intensities will be modelled as smooth functions of time and can further be related to parametric as well as nonparametric covariate effects. Covariates with time-varying effects and frailty terms can be included in addition. Inference will be conducted either fully Bayesian using Markov chain Monte Carlo simulation techniques or empirically Bayesian based on a mixed model representation. A counting process representation of semiparametric multi-state models provides the likelihood formula and also forms the basis for model validation via martingale residual processes. As an application, we will consider human sleep data with a discrete set of sleep states such as REM and Non-REM phases. In this case, simple parametric approaches are inappropriate since the dynamics underlying human sleep are strongly varying throughout the night and individual-specific variation has to be accounted for using covariate information and frailty terms

Release of vasopressin from isolated permeabilized neurosecretory nerve terminals is blocked by the light chain of botulinum A toxin

The intracellular action on exocytosis of botulinim A toxin and constituent chains was studied using permeabilized isolated nerve endings from the rat neural lobe. The release of the neuropeptide vasopressin was measured by radioimmunoassay. In the presence of the reducing agent dithiothreitol, the two-chain form of botulinum A toxin inhibited vasopressin release induced by 10 μM free calcium. Half maximal inhibition was obtained with 15 nM botulinum A toxin. In the absence of the heavy chain the light chain of the toxin strongly inhibited exocytosis with a half maximal effect of 2.5 nM. The inhibitory effects on secretion could be prevented by incubating the light chain with an immune serum against botulinum A toxin. The heavy chain of botulinum A toxin did not affect vasopressin release. However, it prevented the inhibitory effects of the light chain on stimulated exocytosis. It is concluded that botulinum A toxin inhibits the calcium-dependent step leading to exocytosis by interfering with a target present in the isolated and permeabilized nerve terminals. The functional domain of this neurotoxin, which is responsible for the inhibition of vasopressin release, is present in its light chain

Quantum hypercomputation based on the dynamical algebra su(1,1)

An adaptation of Kieu's hypercomputational quantum algorithm (KHQA) is presented. The method that was used was to replace the Weyl-Heisenberg algebra by other dynamical algebra of low dimension that admits infinite-dimensional irreducible representations with naturally defined generalized coherent states. We have selected the Lie algebra $\mathfrak{su}(1,1)$, due to that this algebra posses the necessary characteristics for to realize the hypercomputation and also due to that such algebra has been identified as the dynamical algebra associated to many relatively simple quantum systems. In addition to an algebraic adaptation of KHQA over the algebra $\mathfrak{su}(1,1)$, we presented an adaptations of KHQA over some concrete physical referents: the infinite square well, the infinite cylindrical well, the perturbed infinite cylindrical well, the P{\"o}sch-Teller potentials, the Holstein-Primakoff system, and the Laguerre oscillator. We conclude that it is possible to have many physical systems within condensed matter and quantum optics on which it is possible to consider an implementation of KHQA.Comment: 25 pages, 1 figure, conclusions rewritten, typing and language errors corrected and latex format changed minor changes elsewhere and

HLA-G: expression in human keratinocytes in vitro and in human skin in vivo

Classical, polymorphic major histocompatibility complex class I molecules are expressed on most nucleated cells.They present peptides at the cell surface and, thus, enable the immune system to scan peptides for their antigenicity. The function of the other, nonclassical class I molecules in man is controversial. HLA-G which has been shown by transfection experiments to be expressed at the cell surface, is only transcribed in placental tissue and in the fetal eye.Therefore, a role of HLA-G in the control of rejection of the allogeneic fetus has been discussed. We found that HLA-G expression is induced in keratinocytes by culture in vitro. Three different alternative splicing products of HLA-G can be detected: a full length transcript, an mRNA lacking exon 3 and a transcript devoid of exon 3 and 4. Reverse transcription followed by polymerase chain reaction also revealed the presence of HLA-G mRNA in vivo in biopsies of either diseased or healthy skin

Total hepatectomy and liver transplant for hepatocellular adenomatosis and focal nodular hyperplasia.

Extensive hepatocellular adenomatosis (HA) and focal nodular hyperplasia (FNH) represent a proliferation of hepatic cells that occurs most frequently in women. These lesions are uncommon in the pediatric age group, accounting for 2% of pediatric hepatic tumors, and are extremely rare in males. The etiology of HA and FNH has been correlated with the use of oral contraceptives. We report to the best of our knowledge the first series of patients treated with OLTx for HA and FNH (five cases). All these patients had lesions involving at least 90% of the hepatic parenchyma and all underwent major hepatic surgery before OLTx because of life threatening complications. One patient died in the immediate postoperative period following retransplantation for primary non-function of the first OLTx. Four out of five patients are currently alive from 4.1 to 9.6 years after OLTx. Our results justify the use of OLTx for symptomatic patients with HA and FNH who cannot be treated with conventional hepatic resections

Absolute Income Inequality and Rising House Prices

Income inequality and house prices have risen sharply in developed countries during the last three decades. We argue that this co-movement is no coincidence but that inequality has driven up house prices on the grounds that it raises the total demand for houses, which inflates their prices considering supply restrictions. To test this hypothesis, we conduct cointegration tests for a panel of 18 OECD countries for the period 1975-2010. The results suggest that income inequality and house prices in most OECD countries are positively correlated and cointegrated, and that in the majority of cases absolute inequality Granger-causes house prices when measured in absolute terms. Relative inequality, on the other hand, is not cointegrated with house prices, which is expected given that total house demand depends on the absolute amount of investible income

Principal component and Voronoi skeleton alternatives for curve reconstruction from noisy point sets

Surface reconstruction from noisy point samples must take into consideration the stochastic nature of the sample -- In other words, geometric algorithms reconstructing the surface or curve should not insist in following in a literal way each sampled point -- Instead, they must interpret the sample as a “point cloud” and try to build the surface as passing through the best possible (in the statistical sense) geometric locus that represents the sample -- This work presents two new methods to find a Piecewise Linear approximation from a Nyquist-compliant stochastic sampling of a quasi-planar C1 curve C(u) : R → R3, whose velocity vector never vanishes -- One of the methods articulates in an entirely new way Principal Component Analysis (statistical) and Voronoi-Delaunay (deterministic) approaches -- It uses these two methods to calculate the best possible tape-shaped polygon covering the planarised point set, and then approximates the manifold by the medial axis of such a polygon -- The other method applies Principal Component Analysis to find a direct Piecewise Linear approximation of C(u) -- A complexity comparison of these two methods is presented along with a qualitative comparison with previously developed ones -- It turns out that the method solely based on Principal Component Analysis is simpler and more robust for non self-intersecting curves -- For self-intersecting curves the Voronoi-Delaunay based Medial Axis approach is more robust, at the price of higher computational complexity -- An application is presented in Integration of meshes originated in range images of an art piece -- Such an application reaches the point of complete reconstruction of a unified mes

Influencia de las horas trabajadas por un empleado en su productividad

En este artículo se propone establecer la influencia de las horas trabajadas en la productividad de los empleados en Colombia -- Para esto se realizó una revisión de la literatura acerca de la productividad laboral, se recurrió a investigaciones realizadas por Organizaciones reconocidas, se consultaron casos de éxito en otros países donde se ha implementado la reducción de la jornada laboral, y se aplicaron encuestas en empresas de la ciudad de Medellín -- Como resultado se concluye que las mejoras en la productividad laboral no dependen de un único factor (reducción de las horas de trabajo), sino también de otros factores como la tecnología, innovación, niveles de educación, entre otros, en los cuales Colombia, aunque viene haciendo un esfuerzo importante para desarrollarlos, debe trabajar más en ellos para lograr mayores fortalezas y eficiencia