University of Antwerp

About: University of Antwerp is a education organization based out in Antwerp, Belgium. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 16682 authors who have published 48837 publications receiving 1689748 citations. The organization is also known as: Universiteit Antwerpen & UAntwerp.

Temporal and among-site variability of inherent water-use efficiency at the ecosystem level

Abstract: Half-hourly measurements of the net exchanges of carbon dioxide and water vapor between terrestrial ecosystems and the atmosphere provide estimates of gross primary production (GPP) and evapotranspiration (ET) at the ecosystem level and on daily to annual timescales. The ratio of these quantities represents ecosystem water use efficiency. Its multiplication with mean daylight vapor pressure deficit (VPD) leads to a quantity which we call “inherent water use efficiency” (IWUE*). The dependence of IWUE* on environmental conditions indicates possible adaptive adjustment of ecosystem physiology in response to a changing environment. IWUE* is analyzed for 43 sites across a range of plant functional types and climatic conditions. IWUE* increases during short-term moderate drought conditions. Mean annual IWUE* varied by a factor of 3 among all sites. This is partly explained by soil moisture at field capacity, particularly in deciduous broad-leaved forests. Canopy light interception sets the upper limits to canopy photosynthesis, and explains half the variance in annual IWUE* among herbaceous ecosystems and evergreen needle-leaved forests. Knowledge of IWUE* offers valuable improvement to the representation of carbon and water coupling in ecosystem process models

Proanthocyanidins in Health Care: Current and New Trends

Abstract: Polyphenolic compounds are widely distributed in higher plants and are an integral part of the human diet. Recent interest in these substances has been stimulated by their potential health benefits, which are believed to arise mainly from their antioxidant activity. In the past years, the antioxidant activity of flavonoids has been studied in detail. An important but often overlooked group of polyphenols is that of the proanthocyanidins. Therefore, the present review is focused mainly on the antioxidant activity of proanthocyanidins and its relevancy in vivo. The three most important mechanisms of their antioxidant action will be discussed, i.e. free radical scavenging activity, chelation of transition metals, and inhibition of enzymes. In addition, the protective role of proanthocyanidins against lipid peroxidation and peroxynitrite, as well as their antimicrobial properties will be discussed. To study the in vivo relevancy of the proanthocyanidin activities, the knowledge of their pharmacokinetic parameters is crucial. Although bioavailability and metabolism data on polyphenols in general and proanthocyanidins in particular are still largely unavailable, the first reports indicate that at least monomers and smaller oligomeric procyanidins are absorbed. There is also considerable scientific and public interest in the important role that antioxidants may play in health care, e.g. by acting as cancer chemopreventive and anti-inflammatory agents and by reducing risk of cardiovascular mortality. Each of these aspects will be discussed, with special attention to the role of proanthocyanidins on apoptosis, gene expression and transcription factors, such as NF-kappa B.

Constraints on the spin-parity and anomalous HVV couplings of the Higgs boson in proton collisions at 7 and 8 TeV

Abstract: The study of the spin-parity and tensor structure of the interactions of the recently discovered Higgs boson is performed using the H to ZZ, Z gamma*, gamma* gamma* to 4 l, H to WW to l nu l nu, and H to gamma gamma decay modes. The full dataset recorded by the CMS experiment during the LHC Run 1 is used, corresponding to an integrated luminosity of up to 5.1 inverse femtobarns at a center-of-mass energy of 7 TeV and up to 19.7 inverse femtobarns at 8 TeV. A wide range of spin-two models is excluded at a 99% confidence level or higher, or at a 99.87% confidence level for the minimal gravity-like couplings, regardless of whether assumptions are made on the production mechanism. Any mixed-parity spin-one state is excluded in the ZZ and WW modes at a greater than 99.999% confidence level. Under the hypothesis that the resonance is a spin-zero boson, the tensor structure of the interactions of the Higgs boson with two vector bosons ZZ, Z gamma, gamma gamma, and WW is investigated and limits on eleven anomalous contributions are set. Tighter constraints on anomalous HVV interactions are obtained by combining the HZZ and HWW measurements. All observations are consistent with the expectations for the standard model Higgs boson with the quantum numbers J[PC]=0[++].