62 results match your criteria: "University of Antwerp. Campus Drie Eiken[Affiliation]"

Species interactions determine the spatial mortality patterns emerging in plant communities after extreme events.

Sci Rep

June 2015

Research Group Plant and Vegetation Ecology, Department of Biology, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, B-2610 Wilrijk, Belgium.

Gap disturbance is assumed to maintain species diversity by creating environmental heterogeneity. However, little is known about how interactions with neighbours, such as competition and facilitation, alter the emerging gap patterns after extreme events. Using a spatially explicit community model we demonstrate that negative interactions, especially intraspecific competition, greatly promote both average gap size and gap-size diversity relative to positive interspecific interaction.

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A new species of freshwater amphipod, Pseudingolfiella possessionis n. sp. (Senticaudata, Pseudingolfiellidae), is described from the submerged moss vegetation of small brooklets at sub-Antarctic Île de La Possession, Crozet archipelago.

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Species coexistence in a lattice-structured habitat: effects of species dispersal and interactions.

J Theor Biol

October 2014

State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China. Electronic address:

Opinions differ on how the spatial distribution of species over space affects species coexistence. Here, we constructed both mean-field and pair approximation (PA) models to explore the effects of interspecific and intraspecific interactions and dispersal modes on species coexistence. We found that spatial structure resulting from species dispersal traits and neighboring interactions in PA model did not promote coexistence if two species had the same traits, though it might intensify the contact frequency of intraspecific competition.

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Elevated CO2 concentrations and extreme climate events, are two increasing components of the ongoing global climatic change factors, may alter plant chemical composition and thereby their economic and ecological characteristics, e.g. nutritional quality and decomposition rates.

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Species persistence in landscapes with spatial variation in habitat quality: a pair approximation model.

J Theor Biol

October 2013

Research Group Plant and Vegetation Ecology, Department of Biology, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, B-2610 Wilrijk, Belgium.

Habitat degradation has become a major threat to species persistence. Although several models have explicitly integrated habitat quality into metapopulation dynamics, we still lack knowledge of the spatial variability of species persistence which may result from the clustering of habitat patches of differing quality. Here we construct both pair approximation (PA) and cellular automaton (CA) models for species persistence in homogeneous versus heterogeneous landscapes.

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Practical Model for First Hyperpolarizability Dispersion Accounting for Both Homogeneous and Inhomogeneous Broadening Effects.

J Phys Chem Lett

August 2012

‡School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics (COPE), Georgia Institute of Technology, Atlanta, Georgia, United States.

Article Synopsis
  • A new dispersion model has been developed to accurately determine molecular first hyperpolarizability (β), taking into account both homogeneous and inhomogeneous line broadening effects.
  • By integrating the absorption spectrum with a key parameter for inhomogeneous line width, the model provides a reliable framework for analyzing nonlinear optical data without needing detailed information on line broadening mechanisms.
  • When applied to the NLO chromophore picolinium quinodimethane, the model produced an excellent fit for two-photon resonant data, yielding a static β value of 316 × 10(-30) esu, while adding a second electronic excited state improved short-wavelength descriptions but had minimal impact on the β value.
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Crosstalk between viruses and PML nuclear bodies: a network-based approach.

Front Biosci (Landmark Ed)

June 2011

Laboratory of Protein Science, Proteomics and Epigenetic Signal Transduction, Department of Biomedical Sciences, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, Building T, 2610 Wilrijk, Belgium.

Due to the recent advances in instrumental and scientific methods, cell biology data are generated with increasing speed and quantity. One of these fast developing fields is the crosstalk between promyelocytic leukemia protein nuclear bodies (PML-NBs) and viruses. PML-NBs are dynamic nuclear protein aggregates which are targeted by entire viral particles, viral proteins or viral nucleic acids.

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Interaction of prolyl oligopeptidase with α-synuclein.

CNS Neurol Disord Drug Targets

May 2011

Laboratory of Medical Biochemistry, University of Antwerp - Campus Drie Eiken, Wilrijk, Belgium.

Prolyl oligopeptidase (PO) interacts with α-syncline in vitro. It is a weak interaction that induces a nucleation prone conformation of α-synuclein. PO accelerates aggregation and fibril formation of α-syncline in a process that can be reversed by specific inhibitors and is also influenced by an impairing mutation in the PO active site.

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Structure and function relationship in prolyl oligopeptidase.

CNS Neurol Disord Drug Targets

May 2011

Laboratory of Medical Biochemistry, University of Antwerp - Campus Drie Eiken, Wilrijk, Belgium.

Prolyl oligopeptidase (POP) belongs to a unique class of serine proteases. Based on extensive enzyme kinetic measurements it has become clear that POP acts in a multifaceted way. This is reflected in the complex behavior in different reaction conditions with different substrates.

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The first hyperpolarizability (β) dispersion curve is measured for the first time for an octupolar nonlinear optical (NLO) molecule (crystal violet, CV) and modeled theoretically, yielding an in-depth understanding of the electronic structure and vibronic and solvation effects on such octupolar conjugated systems. Tunable wavelength hyper-Rayleigh scattering (HRS) measurements were performed on this prototypical octupolar molecule in the broad fundamental wavelength range of 620-1580 nm, showing significant shortcomings of the commonly used β dispersion models. Three well-separated β resonances involving the lowest-energy state and several higher excited states are clearly observed, including a significant contribution from a nominally one-photon forbidden transition.

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Single-file transport of water into carbon nanotubes is experimentally demonstrated for the first time through the splitting of the radial breathing mode (RBM) vibration in Raman spectra of bile salt solubilized tubes when both empty (closed) and water-filled (open-ended) tubes are present. D2O filling is observed for a wide range of diameters, d, down to very thin tubes [e.g.

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A manually curated network of the PML nuclear body interactome reveals an important role for PML-NBs in SUMOylation dynamics.

Int J Biol Sci

January 2010

Laboratory of Protein Chemistry, Proteomics and Signal Transduction, Department of Biomedical Sciences, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1 - Building T, Wilrijk, Belgium.

Promyelocytic Leukaemia Protein nuclear bodies (PML-NBs) are dynamic nuclear protein aggregates. To gain insight in PML-NB function, reductionist and high throughput techniques have been employed to identify PML-NB proteins. Here we present a manually curated network of the PML-NB interactome based on extensive literature review including database information.

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Characterization of atmospheric aerosols at a forested site in central Europe.

Environ Sci Technol

July 2009

Department of Pharmaceutical Sciences, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610 Antwerp, Belgium.

Mass concentrations, mass size distributions, time series, and diel variations for organic tracers and major inorganic ions in aerosols from K-puszta, Hungary, during a 2003 summer period are reported. Emphasis was placed on alpha-beta-pinene secondary organic aerosol (SOA) tracers comprising cis-pinic acid, 3-hydroxyglutaric acid, and 3-methyl-1,2,3-butanetricarboxylic acid. Only cis-pinic acid and the d-limonene SOA tracer 3-carboxyheptanedioic acid exhibited diel variations with highest concentrations at night Malic acid was fairly well correlated with succinic and oxalic acid, pointing to a similar SOA formation process.

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Greater impact of extreme drought on photosynthesis of grasslands exposed to a warmer climate in spite of acclimation.

Physiol Plant

May 2009

Research Group of Plant and Vegetation Ecology, Department of Biology, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610 Wilrijk, Belgium.

In view of the projected increase in the frequency of extreme events during this century, we investigated the impact of a drought extreme on leaf ecophysiological parameters and carbon isotope composition (delta(13)C) of grassland communities with species richness (S) of one, three or nine species. The communities, grown for 3 years at either ambient air temperatures (ambient T(air)) or ambient T(air) + 3 degrees C (elevated T(air)), were additionally subjected to an imposed drought by withholding water for 24 days. During the previous 3 years equal precipitation was applied in both temperature treatments, thus communities at elevated T(air) had experienced more frequent, mild droughts.

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Sleep-disordered breathing is highly prevalent in childhood obesity. Two recent cross-sectional studies have demonstrated an independent association between the severity of sleep-disordered breathing and the metabolic syndrome. A limited number of studies have also addressed the correlation between sleep-disordered breathing and insulin resistance, the core factor of the metabolic syndrome.

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Polar organic marker compounds in PM2.5 aerosol from a mixed forest site in western Germany.

Chemosphere

November 2008

Department of Pharmaceutical Sciences, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610 Antwerp, Belgium.

The molecular composition of PM2.5 (particulate matter with an aerodynamic diameter <2.5 microm) aerosol samples collected during a very warm and dry 2003 summer period at a mixed forest site in Jülich, Germany, was determined by gas chromatography/mass spectrometry in an effort to evaluate photooxidation products of biogenic volatile organic compounds (BVOCs) and other markers for aerosol source characterization.

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Biogenic volatile organic compounds (VOCs), such as isoprene and alpha-/beta-pinene, are photo-oxidized in the atmosphere to non-volatile species resulting in secondary organic aerosol (SOA). The goal of this study was to examine time trends and diel variations of oxidation products of isoprene and alpha-/beta-pinene in order to investigate whether they are linked with meteorological parameters or trace gases. Separate day-night aerosol samples (PM(1)) were collected in a Scots pine dominated forest in southern Finland during 28 July-11 August 2005 and analyzed with gas chromatography/mass spectrometry (GC/MS).

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Background And Objective: Indicators to measure the quality of healthcare are increasingly used by healthcare professionals and policy makers. In the context of increasing antimicrobial resistance, this study aimed to develop valid drug-specific quality indicators for outpatient antibiotic use in Europe, derived from European Surveillance of Antimicrobial Consumption (ESAC) data.

Methods: 27 experts (15 countries), in a European Science Foundation workshop, built on the expertise within the European Drug Utilisation Research Group, the General Practice Respiratory Infections Network, the ESCMID Study Group on Primary Care Topics, the Belgian Antibiotic Policy Coordination Committee, the World Health Organization, ESAC, and other experts.

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In the present study, we have characterized in detail the MS(2) and MS(3) fragmentation behaviors, using electrospray ionization (ESI) in the negative ion mode, of previously identified sulfated isoprene secondary organic aerosol compounds, including 2-methyltetrols, 2-methylglyceric acid, 2-methyltetrol mononitrate derivatives, glyoxal and methylglyoxal. A major fragmentation pathway for the deprotonated molecules of the sulfate esters of 2-methyltetrols and 2-methylglyceric acid and of the sulfate derivatives of glyoxal and methylglyoxal is the formation of the bisulfate [HSO(4)](-) anion, while the deprotonated sulfate esters of 2-methyltetrol mononitrate derivatives preferentially fragment through loss of nitric acid. Rational interpretation of MS(2), MS(3) and accurate mass data led to the structural characterization of unknown polar compounds in K-puszta fine aerosol as organosulfate derivatives of photooxidation products of unsaturated fatty acids, i.

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Malignant hyperthermia is an autosomal dominant myopathy triggered by volatile anesthetics or succinylcholine in susceptible persons. While in vitro contracture testing (IVCT) is the gold standard to establish malignant hyperthermia (MH) susceptibility, genetic analysis is increasingly used to diagnose this condition. This work aimed to determine the frequency and distribution of ryanodine receptor (RYR1) mutations in the Belgian MH-population as investigated by IVCT in our centre, as well as the discordance rates between the 2 techniques.

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Ten-year antibody persistence induced by hepatitis A and B vaccine (Twinrix) in adults.

Travel Med Infect Dis

May 2007

Centre for the Evaluation of Vaccination, WHO Collaborating Centre for Prevention and Control of Viral Hepatitis, Unit of Epidemiology and Social Medicine, University of Antwerp - Campus Drie Eiken, Wilrijk, Belgium.

Background: Hepatitis A and B infections are prevalent worldwide and cause significant morbidity and mortality. A combined vaccine providing dual protection against hepatitis A and B is available (Twinrix, GlaxoSmithKline Biologicals).

Method: Two cohorts of adults aged 17-43 years were vaccinated with Twinrix according to a 0, 1, 6 months schedule and followed up for 10 years.

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Hydroxydicarboxylic acids: markers for secondary organic aerosol from the photooxidation of alpha-pinene.

Environ Sci Technol

March 2007

Department of Pharmaceutical Sciences, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610 Antwerp, Belgium.

Detailed organic analysis of fine (PM2.5) rural aerosol collected during summer at K-puszta, Hungary from a mixed deciduous/coniferous forest site shows the presence of polar oxygenated compounds that are also formed in laboratory irradiated alpha-pinene/NOx/air mixtures. In the present work, two major photooxidation products of alpha-pinene were characterized as the hydroxydicarboxylic acids, 3-hydroxyglutaric acid, and 2-hydroxy-4-isopropyladipic acid, based on chemical, chromatographic, and mass spectral data.

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In this study we investigated the accumulation, tissue-specific distribution and possible debromination of BDE 209 in a terrestrial songbird species, the European starling, using silastic implants as a method of exposure. BDE 209 accumulated in the blood of the exposed starlings to a mean peak concentration of 16+/-4.1 ng/ml on day 10.

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Convincing or confusing? Economic evaluations of childhood pneumococcal conjugate vaccination--a review (2002-2006).

Vaccine

February 2007

Centre for the Evaluation of Vaccination, Epidemiology and Social Medicine, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, 2610 Antwerp, Belgium.

We review 15 economic analyses of pneumococcal conjugate vaccines, published between 2002 and 2006, in terms of methodology, assumptions, results and conclusions. We found a great diversity in assumptions (eg, vaccine efficacy parameters, incidence rates for both invasive and non-invasive disease) mainly due to local variation in data and opinions. Accordingly, the results varied greatly, from total net savings to over euro 100,000 per discounted QALY gained.

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In the present work, we have characterized in detail the chemical structures of secondary organic aerosol (SOA) components that were generated in a smog chamber and result from the photooxidation of isoprene under high-NO(x) conditions typical for a polluted atmosphere. Isoprene high-NO(x) SOA contains 2-methylglyceric acid (2-MG) and oligoester derivatives thereof. Trimethylsilylation, in combination with capillary gas chromatography (GC)/ion trap mass spectrometry (MS) and detailed interpretation of the MS data, allowed structural characterization the polar oxygenated compounds present in isoprene SOA up to 2-MG trimers.

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