Discrete symmetries in the three-Higgs-doublet model

in Physical Review. D : Particles and Fields (2012), 86(9), 0950305

N-Higgs-doublet models (NHDM) are among the most popular examples of electroweak symmetry breaking mechanisms beyond the Standard Model. Discrete symmetries imposed on the NHDM scalar potential play a ... [more ▼]

N-Higgs-doublet models (NHDM) are among the most popular examples of electroweak symmetry breaking mechanisms beyond the Standard Model. Discrete symmetries imposed on the NHDM scalar potential play a pivotal role in shaping the phenomenology of the model, and various symmetry groups have been studied so far. However, in spite of all efforts, the classification of finite Higgs-family symmetry groups realizable in NHDM for any N>2 is still missing. Here, we solve this problem for the three-Higgs-doublet model by making use of Burnside’s theorem and other results from pure finite group theory which are rarely exploited in physics. Our method and results can also be used beyond high-energy physics, for example, in the study of possible symmetries in three-band superconductors. [less ▲]

Variable Renewable Energy integration and the balancing challenge: Flexibility assessment in Belgium

Poster (2012, November)

The world is facing a historical increase in energy demand and energy consumption. Variable Renewable Energy (VRE) sources are considered as a solution to both environmental issues and energy demand, even ... [more ▼]

The world is facing a historical increase in energy demand and energy consumption. Variable Renewable Energy (VRE) sources are considered as a solution to both environmental issues and energy demand, even though they present high variability and low predictability. Variability and uncertainty are familiar aspects of all power systems. However, the increase of the share of renewable sources leads to new needs in terms of flexible resources. These resources can be provided by four different means: 1. Dispatchable power plants (i.e. with ramp up and ramp down capabilities) 2. Storage systems, mainly in the form of pumping stations. 3. Grid interconnections between countries 4. Demand side management. The present work focuses on the Belgian transmission grid. In order to assess its flexibility, both the technical flexible resource available and the flexibility requirement are evaluated in the considered area and the Present Variable Renewable Energy penetration Potential is calculated. [less ▲]

L'astronomie dans le monde

Article for general public (2012)

Cinquantenaire de l’ESO;Constante de Hubble; Une comète brillante dans un an ?; Cratère Eltanin

Greening the Common Agricultural Policy (CAP). The Analysis of Developments

in Punctul Critic, Quarterly social, political and cultural diagnostic (2012), 6

Mean Expression of the X-Chromosome is Associated with Neuronal Density.

in Frontiers in Neuroscience (2012), 6

Background: Neurodegenerative diseases are characterized by key features such as loss of neurons, astrocytosis, and microglial activation/proliferation. These changes cause differences in the density of ... [more ▼]

Background: Neurodegenerative diseases are characterized by key features such as loss of neurons, astrocytosis, and microglial activation/proliferation. These changes cause differences in the density of cell types between control and disease subjects, confounding results from gene expression studies. Chromosome X (ChrX) is known to be specifically important in the brain. We hypothesized the existence of a chromosomal signature of gene expression associated with the X-chromosome for neurological conditions not normally associated with that chromosome. The hypothesis was investigated using publicly available microarray datasets from studies on Parkinson's disease, Alzheimer's disease, and Huntington's disease. Data were analyzed using Chromowave, an analytical tool for detecting spatially extended expression changes along chromosomes. To examine associations with neuronal density and astrocytosis, the expression of cell specific reporter genes was extracted. The association between these genes and the expression patterns extracted by Chromowave was then analyzed. Further analyses of the X:Autosome ratios for laser dissected neurons, microglia cultures and whole tissue were performed to detect cell specific differences. Results: We observed an extended pattern of low expression of ChrX consistent in all the neurodegenerative disease brain datasets. There was a strong correlation between mean ChrX expression and the pattern extracted from the autosomal genes representing neurons, but not with mean autosomal expression. No chromosomal patterns associated with the neuron specific genes were found on other chromosomes. The chromosomal expression pattern was not present in datasets from blood cells. The X:Autosome expression ratio was also higher in neuronal cells than in tissues with a mix of cell types. Conclusions: The results suggest that neurological disorders show as a reduction in mean expression of many genes along ChrX. The most likely explanation for this finding relates to the documented general up-regulation of ChrX in brain tissue which, this work suggests, occurs primarily in neurons. If validated, this cell specific ChrX expression warrants further research as understanding the biological reasons and mechanisms for this expression, may help to elucidate a connection with the development of neurodegenerative disorders. [less ▲]

Prognostic Value of Serologic and Histologic Markers on Clinical Relapse in Ulcerative Colitis Patients With Mucosal Healing

in American Journal of Gastroenterology (2012, November), 11(107), 1684-92

Osculating circle with microscopes within microscopes

in Foundations of Science (2012)

Classically, an osculating circle at a point of a planar curve is introduced technically, often with formula giving its radius and the coordinates of its center. In this note, we propose a new and ... [more ▼]

Classically, an osculating circle at a point of a planar curve is introduced technically, often with formula giving its radius and the coordinates of its center. In this note, we propose a new and intuitive definition of this concept: among all the circles which have, at the considered point, the same tangent as the studied curve and thus seem equal to the curve through a microscope, the osculating circle is this that seems equal to the curve through a microscope within microscope. [less ▲]

Highly excited states of baryond in large Nc QCD

in Bled Workshops in Physics (2012, November), 13(1), 47-53

Utilisation de la transfusion par les services cliniques en 2011 en RD Congo : leçons à tirer

in Transfusion Clinique et Biologique (2012)

La capture du CO2: un défi pour l'avenir

Scientific conference (2012, November)

General presentation of the CO2 capture technologies, the potential for CO2 valorization and the technology of CO2 storage. Presentation adressed to secondary school teachers.