scispace - formally typeset
Search or ask a question
Institution

Université catholique de Louvain

EducationLouvain-la-Neuve, Belgium
About: Université catholique de Louvain is a education organization based out in Louvain-la-Neuve, Belgium. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 25319 authors who have published 57360 publications receiving 2172080 citations. The organization is also known as: University of Louvain & UCLouvain.


Papers
More filters
Journal ArticleDOI
TL;DR: An existing Potts model is extended to incorporate negative links as well, resulting in a method similar to the clustering of signed graphs, as dealt with in social balance theory, but more general.
Abstract: Detecting communities in complex networks accurately is a prime challenge, preceding further analyses of network characteristics and dynamics. Until now, community detection took into account only positively valued links, while many actual networks also feature negative links. We extend an existing Potts model to incorporate negative links as well, resulting in a method similar to the clustering of signed graphs, as dealt with in social balance theory, but more general. To illustrate our method, we applied it to a network of international alliances and disputes. Using data from 1993-2001, it turns out that the world can be divided into six power blocs similar to Huntington's civilizations, with some notable exceptions.

412 citations

Journal ArticleDOI
Klaus F. X. Mayer1, C. Schüller1, R. Wambutt, George Murphy2  +230 moreInstitutions (21)
16 Dec 1999-Nature
TL;DR: Analysis of 17.38 megabases of unique sequence, representing about 17% of the Arabidopsis genome, reveals 3,744 protein coding genes, 81 transfer RNAs and numerous repeat elements.
Abstract: The higher plant Arabidopsis thaliana (Arabidopsis) is an important model for identifying plant genes and determining their function. To assist biological investigations and to define chromosome structure, a coordinated effort to sequence the Arabidopsis genome was initiated in late 1996. Here we report one of the first milestones of this project, the sequence of chromosome 4. Analysis of 17.38 megabases of unique sequence, representing about 17% of the genome, reveals 3,744 protein coding genes, 81 transfer RNAs and numerous repeat elements. Heterochromatic regions surrounding the putative centromere, which has not yet been completely sequenced, are characterized by an increased frequency of a variety of repeats, new repeats, reduced recombination, lowered gene density and lowered gene expression. Roughly 60% of the predicted protein-coding genes have been functionally characterized on the basis of their homology to known genes. Many genes encode predicted proteins that are homologous to human and Caenorhabditis elegans proteins.

411 citations

Journal ArticleDOI
TL;DR: The results indicate that ABHD6 is a rate-limiting step of 2-AG signaling and is therefore a bona fide member of the endocannabinoid signaling system.
Abstract: The endocannabinoid 2-arachidonoylglycerol (2-AG) regulates neurotransmission and neuroinflammation by activating CB1 cannabinoid receptors on neurons and CB2 cannabinoid receptors on microglia. Enzymes that hydrolyze 2-AG, such as monoacylglycerol lipase, regulate the accumulation and efficacy of 2-AG at cannabinoid receptors. We found that the recently described serine hydrolase alpha-beta-hydrolase domain 6 (ABHD6) also controls the accumulation and efficacy of 2-AG at cannabinoid receptors. In cells from the BV-2 microglia cell line, ABHD6 knockdown reduced hydrolysis of 2-AG and increased the efficacy with which 2-AG can stimulate CB2-mediated cell migration. ABHD6 was expressed by neurons in primary culture and its inhibition led to activity-dependent accumulation of 2-AG. In adult mouse cortex, ABHD6 was located postsynaptically and its selective inhibition allowed the induction of CB1-dependent long-term depression by otherwise subthreshold stimulation. Our results indicate that ABHD6 is a rate-limiting step of 2-AG signaling and is therefore a bona fide member of the endocannabinoid signaling system.

411 citations

Journal ArticleDOI
TL;DR: Modifications of dietary intake and fat-mass development in short-chain fructans-treated rats are modified to demonstrate the potential modulation of GLP-1 (7-36) amide and ghrelin by fermentable fibres such as fructan, which are rapidly and extensively fermented in the proximal part of the colon.
Abstract: The hypothesis tested in the present study is that dietary fructans are able to modulate gastrointestinal peptides involved in the control of food intake, namely glucagon-like peptide (GLP)-1 (7-36) amide and ghrelin. After 3 weeks of treatment with a standard diet (control) or the same diet enriched with 100 g fructans varying in their degrees of polymerization (oligofructose (OFS), Synergy 1 (Syn) or long chain inulin)/kg, male Wistar rats were deprived of food for 8 h before sample collection. Dietary energy intake throughout the experiment was significantly lower (P<0.05) in fructans-fed rats than in control rats, leading to a significant decrease (P<0.01) in epidydimal fat mass at the end of the treatment in OFS- and Syn-treated rats. GLP-1 (7-36) amide concentration in portal vein serum was higher in OFS- and Syn-fed than in control rats. Both GLP-1 (7-36) amide concentration and proglucagon mRNA concentrations were significantly greater (P<0.05) in the proximal colonic mucosa of fructans-fed rats v. controls. Normally active ghrelin concentration in plasma increases during food deprivation and rapidly falls during a meal. In the present study, after 8 h of food deprivation, active ghrelin in the plasma remained significantly lower (P<0.05) in OFS and Syn-fed than in control rats. These results are in accordance with the modifications of dietary intake and fat-mass development in short-chain fructans-treated rats and demonstrate the potential modulation of GLP-1 (7-36) amide and ghrelin by fermentable fibres such as fructans, which are rapidly and extensively fermented in the proximal part of the colon.

411 citations

Journal ArticleDOI
TL;DR: The auxin/cytokinin ratio in the leaves and roots may explain both the salinity-induced decrease in shoot vigour and the shift in biomass allocation to the roots, in agreement with changes in the activity of the sink-related enzyme cell wall invertase.
Abstract: Following exposure to salinity, the root/shoot ratio is increased (an important adaptive response) due to the rapid inhibition of shoot growth (which limits plant productivity) while root growth is maintained. Both processes may be regulated by changes in plant hormone concentrations. Tomato plants (Solanum lycopersicum L. cv Moneymaker) were cultivated hydroponically for 3 weeks under high salinity (100 mM NaCl) and five major plant hormones (abscisic acid, ABA; the cytokinins zeatin, Z, and zeatin-riboside, ZR; the auxin indole-3-acetic acid, IAA; and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid, ACC) were determined weekly in roots, xylem sap, and leaves. Salinity reduced shoot biomass by 50-60% and photosynthetic area by 20-25% both by decreasing leaf expansion and delaying leaf appearance, while root growth was less affected, thus increasing the root/shoot ratio. ABA and ACC concentrations strongly increased in roots, xylem sap, and leaves after 1 d (ABA) and 15 d (ACC) of salinization. By contrast, cytokinins and IAA were differentially affected in roots and shoots. Salinity dramatically decreased the Z+ZR content of the plant, and induced the conversion of ZR into Z, especially in the roots, which accounted for the relative increase of cytokinins in the roots compared to the leaf. IAA concentration was also strongly decreased in the leaves while it accumulated in the roots. Decreased cytokinin content and its transport from the root to the shoot were probably induced by the basipetal transport of auxin from the shoot to the root. The auxin/cytokinin ratio in the leaves and roots may explain both the salinity-induced decrease in shoot vigour (leaf growth and leaf number) and the shift in biomass allocation to the roots, in agreement with changes in the activity of the sink-related enzyme cell wall invertase.

411 citations


Authors

Showing all 25540 results

NameH-indexPapersCitations
Robert Langer2812324326306
Pulickel M. Ajayan1761223136241
Klaus Müllen1642125140748
Giacomo Bruno1581687124368
Willem M. de Vos14867088146
David Goldstein1411301101955
Krzysztof Piotrzkowski141126999607
Andrea Giammanco135136298093
Christophe Delaere135132096742
Vincent Lemaitre134131099190
Michael Tytgat134144994133
Jian Li133286387131
Jost B. Jonas1321158166510
George Stephans132133786865
Peter Hall132164085019
Network Information
Related Institutions (5)
Katholieke Universiteit Leuven
176.5K papers, 6.2M citations

95% related

University of Paris
174.1K papers, 5M citations

95% related

Centre national de la recherche scientifique
382.4K papers, 13.6M citations

94% related

Utrecht University
139.3K papers, 6.2M citations

93% related

University of Amsterdam
140.8K papers, 5.9M citations

93% related

Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2023147
2022424
20212,952
20202,969
20192,752
20182,676