University of Luxembourg

About: University of Luxembourg is a education organization based out in Luxembourg, Luxembourg. It is known for research contribution in the topics: Context (language use) & Computer science. The organization has 4744 authors who have published 22175 publications receiving 381824 citations.

Conditional Neuronal Nitric Oxide Synthase Overexpression Impairs Myocardial Contractility

Abstract: The role of the neuronal NO synthase (nNOS or NOS1) enzyme in the control of cardiac function still remains unclear. Results from nNOS / mice or from pharmacological inhibition of nNOS are contradictory and do not pay tribute to the fact that probably spatial confinement of the nNOS enzyme is of major importance. We hypothesize that the close proximity of nNOS and certain effector molecules like L-type Ca 2 -channels has an impact on myocardial contractility. To test this, we generated a new transgenic mouse model allowing conditional, myocardial specific nNOS overexpression. Western blot analysis of transgenic nNOS overexpression showed a 6-fold increase in nNOS protein expression compared with noninduced littermates (n12; P0.01). Measuring of total NOS activity by conversion of ( 3 H)-L-arginine to ( 3 H)-L-citrulline showed a 30% increase in nNOS overexpressing mice (n18; P0.05). After a 2 week induction, nNOS overexpression mice showed reduced myocardial contractility. In vivo examinations of the nNOS overexpressing mice revealed a 173% decrease of dp/dtmax compared with noninduced mice (P0.05). Likewise, ejection fraction was reduced significantly (42% versus 65%; n15; P0.05). Interestingly, coimmunoprecipitation experiments indicated interaction of nNOS with SR Ca 2 ATPase and additionally with L-type Ca 2 - channels in nNOS overexpressing animals. Accordingly, in adult isolated cardiac myocytes, ICa,L density was significantly decreased in the nNOS overexpressing cells. Intracellular Ca 2 -transients and fractional shortening in cardiomyocytes were also clearly impaired in nNOS overexpressing mice versus noninduced littermates. In conclusion, conditional myocardial specific overexpression of nNOS in a transgenic animal model reduced myocardial contractility. We suggest that nNOS might suppress the function of L-type Ca 2 -channels and in turn reduces Ca 2 -transients which accounts for the negative inotropic effect. (Circ Res. 2007;100:e32-e44.)

Stein's method and normal approximation of Poisson functionals

Abstract: We combine Stein's method with a version of Malliavin calculus on the Poisson space. As a result, we obtain explicit Berry-Ess\'een bounds in Central Limit Theorems (CLTs) involving multiple Wiener-It\^o integrals with respect to a general Poisson measure. We provide several applications to CLTs related to Ornstein-Uhlenbeck L\'evy processes.

Functional differences between L- and T-plastin isoforms.

Abstract: Fimbrins/plastins are a family of highly conserved actin-bundling proteins They are present in all eukaryotic cells including yeast, but each isoform displays a remarkable tissue specificity T-plastin is normally found in epithelial and mesenchymal cells while L-plastin is present in hematopoietic cells However, L-plastin has been also found in tumor cells of non-hematopoietic origin (Lin, C-S, R H Aebersold, S B Kent, M Varma, and J Leavitt 1988 Mol Cell Biol 8:4659-4668; Lin, C-S, R H Aebersold, and J Leavitt 1990 Mol Cell Biol 10: 1818-1821) To learn more about the biological significance of their tissue specificity, we have overproduced the T- and L-plastin isoforms in a fibroblast-like cell line, CV-1, and in a polarized epithelial cell line, LLC-PK1 In CV-1 cells, overproduction of T- and L-plastins induces cell rounding and a concomitant reorganization of actin stress fibers into geodesic structures L-plastin remains associated with microfilaments while T-plastin is almost completely extracted after treatment of the cells with non-ionic detergent In LLC-PK1 cells, T-plastin induces shape changes in microvilli and remains associated with microvillar actin filaments after detergent extraction while L-plastin has no effect on these structures and is completely extracted The effect of T-plastin on the organization of microvilli differs from that of villin, another actin-bundling protein Our experiments indicate that these two isoforms play differing roles in actin filament organization, and do so in a cell type-specific fashion Thus it is likely that these plastin isoforms play fundamentally different roles in cell function

Community Transitions to Low Carbon Futures in the Transition Towns Network (TTN)

Abstract: This paper examines the use of ‘community’ rhetoric in the Transition Town Network (TTN). This is seen in both its external and internal context. Externally, TTN has emerged against the backdrop of an increasing use of ‘community’ rhetoric in environmental governance, for example, in renewable energy projects. Internally, the use of ‘community’ language and ‘community’ ways of operating are crucial for understanding this movement, in how it sees itself and the lineage it builds upon. Particularly, TTN builds upon the polysemic, subjective nature of the word, fused with their unique permaculture inspired meaning. TTN have emerged as an important response to climate change and peak oil (Bailey et al. 2010; Mason and Whitehead 2011). This paper attempts to address their crucial, if neglected, focus on ‘community’. In the wide sweep of writing on ‘community’, what distinctive, if anything, can TTN add to current understandings and practices of ‘community’?

TBar: revisiting template-based automated program repair

Abstract: We revisit the performance of template-based APR to build comprehensive knowledge about the effectiveness of fix patterns, and to highlight the importance of complementary steps such as fault localization or donor code retrieval. To that end, we first investigate the literature to collect, summarize and label recurrently-used fix patterns. Based on the investigation, we build TBar, a straightforward APR tool that systematically attempts to apply these fix patterns to program bugs. We thoroughly evaluate TBar on the Defects4J benchmark. In particular, we assess the actual qualitative and quantitative diversity of fix patterns, as well as their effectiveness in yielding plausible or correct patches. Eventually, we find that, assuming a perfect fault localization, TBar correctly/plausibly fixes 74/101 bugs. Replicating a standard and practical pipeline of APR assessment, we demonstrate that TBar correctly fixes 43 bugs from Defects4J, an unprecedented performance in the literature (including all approaches, i.e., template-based, stochastic mutation-based or synthesis-based APR).