Showing papers by "University of Luxembourg published in 2003"

Pragmatism and educational research

Abstract: Chapter 1 Series Preface Nicholas C. Burbules Chapter 3 1. What is Pragmatism? Chapter 4 2. From Experience to Knowledge Chapter 5 3. The Process of Inquiry Chapter 6 4. Consequences of Pragmatism Chapter 7 5. Pragmatism and Educational Research

Teacher Reflection in a Hall of Mirrors: Historical Influences and Political Reverberations

Abstract: This article traces the genealogy of reflection in teacher education by seeking the conditions of its emergence through the influences of Descartes, Dewey, Schon, and feminism. Drawing on the critical lenses of Foucaultian genealogy and the sociology of scientific knowledge, the analysis investigates how the complicated meanings of reflection get played out in complex and contradictory ways through research practices. The purpose of this article is to highlight the diversity of meanings that constitute understandings of the term and then to critique the effects of power that reverberate through current reflective practices.

PRODORIC: prokaryotic database of gene regulation

Abstract: The database PRODORIC aims to systematically organize information on prokaryotic gene expression, and to integrate this information into regulatory networks. The present version focuses on pathogenic bacteria such as Pseudomonas aeruginosa. PRODORIC links data on environmental stimuli with trans-acting transcription factors, cis-acting promoter elements and regulon definition. Interactive graphical representations of operon, gene and promoter structures including regulator-binding sites, transcriptional and translational start sites, supplemented with information on regulatory proteins are available at varying levels of detail. The data collection provided is based on exhaustive analyses of scientific literature and computational sequence prediction. Included within PRODORIC are tools to define and predict regulator binding sites. It is accessible at http://prodoric.tu-bs.de.

Identification and functional characterization of a novel R621C mutation in the synphilin-1 gene in Parkinson's disease

Abstract: Synphilin-1 is linked to the pathogenesis of Parkinson's disease (PD) based on its identification as an alpha-synuclein (PARK1) and parkin (PARK2) interacting protein. Moreover, synphilin-1 is a component of Lewy bodies (LB) in brains of sporadic PD patients. Therefore, we performed a detailed mutation analysis of the synphilin-1 gene in 328 German familial and sporadic PD patients. In two apparently sporadic PD patients we deciphered a novel C to T transition in position 1861 of the coding sequence leading to an amino acid substitution from arginine to cysteine in position 621 (R621C). This mutation was absent in a total of 702 chromosomes of healthy German controls. To define a possible role of mutant synphilin-1 in the pathogenesis of PD we performed functional analyses in SH-SY5Y cells. We found synphilin-1 capable of producing cytoplasmic inclusions in transfected cells. Moreover we observed a significantly reduced number of inclusions in cells expressing C621 synphilin-1 compared with cells expressing wild-type (wt) synphilin-1, when subjected to proteasomal inhibition. C621 synphilin-1 transfected cells were more susceptible to staurosporine-induced cell death than cells expressing wt synphilin-1. Our findings argue in favour of a causative role of the R621C mutation in the synphilin-1 gene in PD and suggest that the formation of intracellular inclusions may be beneficial to cells and that a mutation in synphilin-1 that reduces this ability may sensitize neurons to cellular stress.

Do Credit Rating Agencies Add to the Dynamics of Emerging Market Crises

Abstract: The experience in the period during and after the Asian crisis of 1997-98 has provoked an extensive debate about the credit rating agencies' evaluation of sovereign risk in emerging markets lending. This study analyzes the role of credit rating agencies in international financial markets, particularly whether sovereign credit ratings have an impact on the financial stability in emerging market economies. The event study and panel regression results indicate that credit rating agencies have substantial influence on the size and volatility of emerging markets lending. The empirical results are significantly stronger in the case of government's downgrades and negative imminent sovereign credit rating actions such as credit watches and rating outlooks than positive adjustments by the credit rating agencies while by the market participants' anticipated sovereign credit rating changes have a smaller impact on financial markets in emerging economies.

Testing conditional moment restrictions

Abstract: Let (x,z) be a pair of observable random vectors We construct a new "smoothed" empirical likelihood-based test for the hypothesis $\E\{ g(z,\break \theta)|x \} = 0$ wp1, where g is a vector of known functions and $\theta$ an unknown finite-dimensional parameter We show that the test statistic is asymptotically normal under the null hypothesis and derive its asymptotic distribution under a sequence of local alternatives Furthermore, the test is shown to possess an optimality property in large samples Simulation evidence suggests that it also behaves well in small samples

The actin cytoskeleton as a therapeutic target: state of the art and future directions.

Abstract: Dynamic processes such as cell migration and division depend on the actin cytoskeleton, a dense meshwork of protein polymers capable of undergoing rapid cycles of assembly and disassembly, under the control of a large number of actin-associated proteins. In cancer cells, structural and functional perturbations of the actin cytoskeleton correlate with higher proliferation rates and uncontrolled movement. Therefore, small molecules that act on the actin cytoskeleton of tumour cells and thus inhibit cell division and movement, may be of high therapeutic value. The dynamic properties of the actin cytoskeleton and the mechanism of action of actin-targeting drugs will be described.

Improvement of Endothelial Dysfunction by Selective Estrogen Receptor-α Stimulation in Ovariectomized SHR

Abstract: Both known estrogen receptors, ERα and ERβ, are expressed in blood vessels. To gain further insight into the role of ERα in a functional setting, we investigated the effect of the novel highly sele...

Perceived parental differential treatment in middle adulthood: Curvilinear relations with individuals' experienced relationship quality to sibling and parents

Abstract: Guided by predictions from equity theory and the self-esteem maintenance model, links between perceptions of current parental differential treatment and the perceiver's experienced relationship quality with sibling and parents were analyzed in a sample of 1,020 adult (middle-aged) offspring. Participants rated how often they and a sibling receive parental recognition, nurture, and demands for filial responsibility. In addition, they indicated their emotions and behaviors toward sibling and parents. Data analyses showed that an individual's experienced relationship with sibling was best when both were treated equally and diminished with increasing favoritism or disfavoritism. Experienced relationship with parents was best when participants were favored a bit; the relationship worsened when participants were disfavored and worsened only slightly when they were extremely favored. Results are discussed regarding mediating processes and implications for practical applications.

Multi-robot decision making using coordination graphs

Abstract: Within a group of cooperating agents the decision making of an individual agent depends on the actions of the other agents. In dynamic environments, these dependencies will change rapidly as a result of the continuously changing state. Via a context-specific decomposition of the problem into smaller subproblems, coordination graphs offer scalable solutions to the problem of multiagent decision making. We will apply coordination graphs to the continuous domain by assigning roles to the agents and then coordinating the different roles. Finally, we will demonstrate this method in the RoboCup soccer simulation domain.

AT2 receptor activation regulates myocardial eNOS expression via the calcineurin–NF-AT pathway

Abstract: The role of AT2-receptors has recently been subject of considerable debate. We investigated the influence of AT2-stimulation/inhibition on myocardial endothelial NO-synthase (eNOS, NOSIII) promoter activity and eNOS protein expression. Stimulation of rat cardiomyocytes with angiotensin II (AngII) increased eNOS protein expression 3.3-fold. This was blocked by Cyclosporin A (CsA). Inhibition of the AT1-receptor did not reduce AngII-mediated eNOS protein expression, whereas AT2 stimulation increased it 2.4-fold and AT2 inhibition suppressed it. The modulatory effects of the AT2-receptor on eNOS expression was confirmed in mice with a genetic deletion of the AT2-receptor (AT2-KO). In gel shift assays two putative NF-AT sites in a 1.6 kb eNOS promoter fragment showed NF-AT binding and a supershift by NF-AT2(-c1)-specific antibodies. Stimulation of transfected cells with AngII or specific AT2-receptor agonists resulted in a significant increase in eNOS promoter activity, which was blocked by CsA, MCIP1, and mutation of an upstream NF-AT site. Conclusion: 1) AngII-stimulation of the myocardium, both in vivo and in vitro, is accompanied by increased expression of eNOS. 2) This effect is mediated by the calcineurin pathway and is induced by the AT2-receptor. 3) These results define a calcineurin/NF-AT/eNOS pathway as downstream effector of AT2-receptor activation in the myocardium.

Higher genus affine Lie algebras of Krichever-Novikov type

Abstract: For higher genus multi-point current algebras of Krichever-Novikov type associated to a finite-dimensional Lie algebra, local Lie algebra two-cocycles are stud- ied. They yield as central extensions almost-graded higher genus affine Lie algebras. In case that the Lie algebra is reductive a complete classification is given. For a sim- ple Lie algebra, like in the classical situation, there is up to equivalence and rescaling only one non-trivial almost-graded central extension. The classification is extended to the algebras of meromorphic differential operators of order less or equal one on the currents algebra.

Polymorphisms of the alpha-synuclein promoter: expression analyses and association studies in Parkinson's disease.

Abstract: Mutations of the alpha-synuclein gene have shown to be relevant in some rare families with autosomal dominant Parkinson's disease (PD). Furthermore, alpha-synuclein protein is a major component of the Lewy bodies also in sporadic PD patients. Increased levels of wildtype alpha-synuclein in the cell leads to increased intracellular hydrogen peroxide levels and causes death of dopaminergic neurons in rat primary culture. Subsequently, oxidative stress has been directly linked with alpha-synuclein aggregation in vitro. This raises the question whether increased alpha-synuclein expression might be linked to higher susceptibility to PD and whether alpha-synuclein promoter polymorphisms are associated with PD. Here, two polymorphisms (-116C>G and -668T>C) of the alpha-synuclein promoter defining four haplotypes have been characterized in 315 German PD patients. The influence of the four haplotypes on gene expression was studied by CAT reporter gene assays in neuronal SK-N-AS cells. The -668C/-116G haplotype revealed significant higher CAT expression than the -668T/-116G or the -668T/-116C haplotype, respectively. Although the -668C/-116G haplotype was more common in PD patients, this difference was not significant.

Local cocycles and central extensions for multi-point algebras of Krichever-Novikov type

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 ex- tensions of the functions algebra, the vector field algebra, and the differential operator algebra (of degree ≤ 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.

Global deformations of the Witt algebra of Krichever-Novikov type

Abstract: By considering non-trivial global deformations of the Witt (and the Virasoro) algebra given by geometric constructions it is shown that, despite their infinitesimal and formal rigidity, they are globally not rigid. This shows the need of a clear indication of the type of deformations considered. The families appearing are constructed as families of algebras of Krichever–Novikov type. They show up in a natural way in the global operator approach to the quantization of two-dimensional conformal field theory. In addition, a proof of the infinitesimal and formal rigidity of the Witt algebra is presented.

Security Council Resolution 1373 and the Constitution of the United Nations

Abstract: In Resolution 1373 the Security Council laid down a series of general and abstract rules binding on all UN member states. In doing so, the Council purported to legislate. This article discusses whether it is entitled to do so. In the light of the Charter and the past practice of United Nations organs, it argues that the Council can only exercise its Chapter VII powers in response to specific situations or conduct. In enacting Resolution 1373 the Council acted ultra vires. The article looks at the circumstances in which such an extension of the Security Council's powers might be acceptable, but concludes that unilateral attempts by the Council to legislate would be destructive of the international legal order.

Urbanization, Urban Concentration and Economic Growth in Developing Countries

Abstract: We investigate how urban concentration and urbanization affect economic growth in developing countries. Using semi-parametric estimation techniques on a cross-country panel of 39 countries for the years 1960-1990 we discover a U-shaped relationship for urban concentration. this suggests the existence of an urban-concentration trap where marginal increases in urban concentration would reduce growth for about a third of our sample. Furthermore, there appears to be no systematic relationship between urbanization and economic growth.

Demokrati - ett problem för utbildning eller ett utbildningsproblem?

Abstract: In this paper I argue that we should not only understand democracy as a problem for education, but that we should also understand democracy as being itself an educational problem. I propose an educational definition of democracy as the situation in which all human beings can be subjects. Next, I discuss Kant’s individual conception of subjectivity, Dewey’s social conception of subjectivity and Arendt’s political conception of subjectivity in order to explore the political and educational implications of this definition. I conclude that we should no longer think of subjectivity as an attribute of individuals, but rather see it as a dimension of human action, namely action in the political sphere, the sphere where we are with others. This implies that the question for democratic education is not about how to ‘create’ or ‘produce’ democratic citizens, but about how to create opportunities for action, for being a subject, both in schools and other educational institutions, and in society as a whole. The learning involved in democratic education is, similarly, not learning how to become or to be a subject, but learning from being and having been a subject.

A comprehensive set of protein complexes in yeast: mining large scale protein-protein interaction screens.

Abstract: Motivation: The analysis of protein–protein interactions allows for detailed exploration of the cellular machinery. The biochemical purification of protein complexes followed by identification of components by mass spectrometry is currently the method, which delivers the most reliable information—albeit that the data sets are still difficult to interpret. Consolidating individual experiments into protein complexes, especially for high-throughput screens, is complicated by many contaminants, the occurrence of proteins in otherwise dissimilar purifications due to functional re-use and technical limitations in the detection. A non-redundant collection of protein complexes from experimental data would be useful for biological interpretation, but manual assembly is tedious and often inconsistent. Results: Here, we introduce a measure to define similarity within collections of purifications and generate a set of minimally redundant, comprehensive complexes using unsupervised clustering. Availability: Programs and results are freely available from

GGFC Special Bureau for Loading: current status and plans

Abstract: The Earth’s surface is perpetually being displaced due to temporally varying atmospheric, oceanic and continental water mass surface loads. These non-geodynamic signals are of substantial magnitude that they contribute significantly to the scatter in geodetic observations of crustal motion. In February, 2002, the International Earth Rotation Service (IERS) established a Special Bureau of Loading (SBL) whose primary charge is to provide consistent and valid estimates of surface mass loading effects to the IERS community for the purpose of correcting geodetic time series. Here we outline the primary principles involved in modelling the surface displacements and gravity changes induced by surface mass loading including the basic theory, the Earth model and the surface load data. We then identify a list of operational issues, including product validation, that need to be addressed by the SBL before products can be provided to the community. Finally, we outline areas for future research to further improve the loading estimates. We conclude by formulating a recommendation on the best procedure for including loading corrections into geodetic data. Success of the SBL will depend on our ability to efficiently provide consistent and reliable estimates of surface mass loading effects. It is imperative that we work closely with the existing Global Geophysical Fluids Center (GGFC) Special Bureaus and with the community to as much as possible to verify the products.

The Discourse of German Geisteswissenschaftliche Pädagogik - A Contextual Reconstruction

Abstract: The framework of German educational discourse of the twentieth century is so‐called geisteswissenschaftliche Padagogik, or education as one of the humanities or arts rather than as a science. It triumphed around 1925 in the second half of the Weimar Republic. This article outlines in three steps the core elements of this educational discourse. First, it shows that the mode of thinking of the exponents of geisteswissenschaftliche Padagogik was dualistic in a traditional Protestant manner. They juxtaposed empiry and Geist, plurality and unity, and outward and inward, and they favoured the inward unity and coherency of Geist. The contextual analysis shows, however, that the dualistic thought schema was virulent not only among German educationalists and philosophers, but also found strong expression in novelists and essayists like Thomas Mann, or the winner of the Nobel Prize for Literature, Rudolf Eucken. Mainstream thinkers criticised the plural systems of Western democracy and capitalism – first and foremo...

Extreme US Stock Market Fluctuations in the Wake of 9/11

Abstract: It is common wisdom that the 9/11 terrorist attacks boosted political and financial uncertainty and resulted in severe stock market meltdowns in the months after the attacks. Taking a sectoral focus of the market for US common stock, we apply statistical extreme value analysis (EVT) to assess whether downside risk measures like Value-at-Risk (VaR) and extremal sector linkages were significantly altered by 9/11. We use a semi-parametric quantile estimator for the VaR in order to test whether downside risk increased after 9/11. We also estimate the co-exceedance probability of observing joint meltdowns in sectoral and market portfolio indices by employing a dependence measure from bivariate extreme value theory. These tail beta's may be thought of as measuring systematic risk during high volatility regimes. Taking 9/11 as the sample midpoint we do find that nearly all sectoral tail beta's have risen over time. This indicates that the potential for domestic portfolio diversification during crisis periods, i.e. when diversification is most needed, decreased compared to the pre-9/11 era. As for the pre-9/11 and post-9/11 VaR estimates, we do not find much support for a structural change in downside risk.

Dry times in Africa

Abstract: While there have been some references in the literature to the potential role of the general decline in rainfall in sub-Saharan African nations on their poor growth performance relative to other developing countries, this avenue remains empirically unexplored. In this paper we use a new cross-country panel climatic data set in an economic growth framework to explore the issue. Our results show that rainfall has been a significant determinant of poor economic growth for Africa, but not for other developing countries. Depending on the benchmark measure of potential rainfall, we estimate that the direct impact under the scenario of no decline in rainfall would have resulted in a reduction of between 13 and 36 per cent of today's gap in African GDP per capita relative to rest of the developing world.

Brain Drain and LDCs? Growth: Winners and Losers

Abstract: We present an empirical evaluation of the growth e¤ects of the brain drain for the source countries of migrants. Using recent US data on migration rates by education levels (Carrington and Detragiache, 1998), we ...nd empirical support for the ”bene...cial brain drain hypothesis” in a sample of 50 developing countries. At the country-level, we distinguish between winners and losers among source countries. While the number of winners is smaller, these include nearly 80% of the total population of developing countries. JEL Classi...cation: F22, J24, O15

Band structure of boron doped carbon nanotubes

Abstract: We present ab initio and self‐consistent tight‐binding calculations on the band structure of single wall semiconducting carbon nanotubes with high degrees (up to 25 %) of boron substitution. Besides a lowering of the Fermi energy into the valence band, a regular, periodic distribution of the p‐dopants leads to the formation of a dispersive “acceptor”‐like band in the band gap of the undoped tube. This comes from the superposition of acceptor levels at the boron atoms with the delocalized carbon π‐orbitals. Irregular (random) boron‐doping leads to a high concentration of hybrids of acceptor and unoccupied carbon states above the Fermi edge.

Agglomeration Economies and the Location of Industries: A Comparison of Three Small European Countries

Abstract: We investigate and compare the spatial distribution of manufacturing activity and its determinants in Belgium, Ireland and Portugal using comparable, exhaustive micro-level data sets. We find some similarities between Portugal and Belgium, but little for Ireland. Moreover, there is some evidence that forward and backward linkages as well as dependence on natural avantages can be important determinants of agglomeration.