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Document Server@UHasselt (59.068 recursos)

Repository of the University of Hasselt containing publications in the fields of statistics, computer science, information strategies and material from the Institute for behavioural sciences.

Research Institute: Centre for Environmental Sciences

Mostrando recursos 1 - 20 de 479

  1. Revision of Phaenocora Ehrenberg, 1836 (Rhabditophora, Typhloplanidae, Phaenocorinae) with the description of two new species

    HOUBEN, Albrecht; VAN STEENKISTE, Niels; ARTOIS, Tom
    A morphological and taxonomical account of the taxon Phaenocora is provided. An effort was made to locate and study all available material and, where possible, species are briefly re-described. We also describe two new species: Phaenocora gilberti sp. nov. from Cootes Paradise, Ontario, Canada and Phaenocora aglobulata sp. nov. from Prairie Grove, Alabama, USA. Species recognition is based on a combination of both male and female morphology. A comparison of and discussion on all species is given, resulting in a total of 28 valid species, three species inquirendae, five species dubiae, and one nomen nudum. An identification key is provided.

  2. Carbon loading in airway macrophages as a biomarker for individual exposure to particulate matter air pollution - A critical review

    Bai, Yang; Brugha, Rossa E.; Jacobs, Lotte; Grigg, Jonathan; NAWROT, Tim; Nemery, Benoit
    Exposure to particulate matter (PM) is associated with adverse health effects, including chronic lung diseases, lung cancer and cardiovascular disease. Personal exposure varies depending on the generation of particles locally, background levels, activity patterns and meteorology. Carbon loading in airway macrophages (AM) is a novel marker to assess personal exposure to combustion-derived particles. This review summarizes the published evidence and describes the validity and reliability of this marker with a focus on the technical aspects. Carbon loading in AM is reported in nine published studies assessing personal exposure to particulate air pollution. The carbon content is quantified by image analysis...

  3. Blood Pressure in Relation to Environmental Lead Exposure in the National Health and Nutrition Examination Survey 2003 to 2010

    Hara, Azusa; Thijs, Lutgarde; Asayama, Kei; Gu, Yu-Mei; Jacobs, Lotte; Zhang, Zhen-Yu; Liu, Yan-Ping; NAWROT, Tim; Staessen, Jan A.
    In view of the declining environmental lead exposure in the United States, we analyzed the National Health and Nutrition Examination Survey (2003-2010) for association of blood pressure and hypertension with blood lead. The 12 725 participants included 21.1% blacks, 20.5% Hispanics, 58.4% whites, and 48.7% women. Blacks compared with non-Blacks had higher systolic and diastolic pressures (126.5 versus 123.9 and 71.9 versus 69.6 mm Hg) and higher hypertension prevalence (44.7 versus 36.8%). Blood lead was lower in whites than in non-whites (1.46 versus 1.57 mu g/dL) and in women than in men (1.25 versus 1.80 mu g/dL). In multivariable analyses...

  4. Renal cells exposed to cadmium in vitro and in vivo: normalizing gene expression data

    RAVINDRAN NAIR, Ambily; SMEETS, Karen; KEUNEN, Els; Lee, Wing-Kee; Thévenod, Frank; VAN KERKHOVE, Emmy; CUYPERS, Ann
    Cadmium (Cd) is a toxic metal with a long half-life in biological systems. This half-life is partly as a result of metallothioneins (MTs), metal-binding proteins with a high affinity for Cd. The high retention properties of the kidneys reside in proximal tubular cells that possess transport mechanisms for Cd-MT uptake, ultimately leading to more Cd accumulation. Researchers have studied MT–metal interactions using various techniques including quantitative real-time PCR (qPCR), an efficient tool for quantifying gene expression. Often a poor choice of reference genes, which is represented by their instability and condition dependency, leads to inefficient normalization of gene expression data...

  5. Glutathione and mitochondria determine acute defense responses and adaptive processes in cadmium-induced oxidative stress and toxicity of the kidney

    Ravindran Nair, Ambily; Lee, Wing-Kee; Smeets, Karen; Swennen, Quirine; Sanchez, Amparo; Thévenod, Frank; Cuypers, Ann
    Cadmium (Cd2+) induces oxidative stress that ultimately defines cell fate and pathology. Mitochondria are the main energy-producing organelles in mammalian cells, but they also have a central role in formation of reactive oxygen species, cell injury, and death signaling. As the kidney is the major target in Cd2+ toxicity, the roles of oxidative signature and mitochondrial function and biogenesis in Cd2+-related stress outcomes were investigated in vitro in cultured rat kidney proximal tubule cells (PTCs) (WKPT-0293 Cl.2) for acute Cd2+ toxicity (1–30 µM, 24 h) and in vivo in Fischer 344 rats for sub-chronic Cd2+ toxicity (1 mg/kg CdCl2 subcutaneously,...

  6. Reliable gene expression analysis by reverse transcription-quantitative PCR: reporting and minimizing the uncertainty in data accuracy.

    REMANS, Tony; KEUNEN, Els; BEX, Geert Jan; SMEETS, Karen; VANGRONSVELD, Jaco; CUYPERS, Ann
    Reverse transcription-quantitative PCR (RT-qPCR) has been widely adopted to measure differences in mRNA levels; however, biological and technical variation strongly affects the accuracy of the reported differences. RT-qPCR specialists have warned that, unless researchers minimize this variability, they may report inaccurate differences and draw incorrect biological conclusions. The Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines describe procedures for conducting and reporting RT-qPCR experiments. The MIQE guidelines enable others to judge the reliability of reported results; however, a recent literature survey found low adherence to these guidelines. Additionally, even experiments that use appropriate procedures remain subject to individual variation...

  7. Wild Flora of Mine Tailings: Perspectives for Use in Phytoremediation of Potentially Toxic Elements in a Semi-Arid Region in Mexico

    Sanchez-Lopez, Ariadna S.; Gonzalez-Chavez, Ma. Del Carmen A.; Carrillo-Gonzalez, Rogelio; VANGRONSVELD, Jaco; Diaz-Garduno, Margarita
    The aim of this research was to identify wild plant species applicable for remediation of mine tailings in arid soils. Plants growing on two mine tailings were identified and evaluated for their potential use in phytoremediation based on the concentration of potentially toxic elements (PTEs) in roots and shoots, bioconcentration (BCF) and translocation factors (TF). Total, water-soluble and DTPA-extractable concentrations of Pb, Cd, Zn, Cu, Co and Ni in rhizospheric and bulk soil were determined. Twelve species can grow on mine tailings, accumulate PTEs concentrations above the commonly accepted phytotoxicity levels, and are suitable for establishing a vegetation cover on...

  8. Arabidopsis thaliana seedlings show an age-dependent response on growth and DNA repair after exposure to chronic gamma-radiation

    BIERMANS, Geert; HOREMANS, Nele; VANHOUDT, Nathalie; Vandenhove, Hildegarde; SAENEN, Eline; Van Hees, May; Wannijn, Jean; VANGRONSVELD, Jaco; CUYPERS, Ann
    The biosphere is constantly exposed to ionising radiation, due to cosmic radiation and the presence of natural and anthropogenic radionuclides in the environment. The biological effects of the resulting radiation exposure are currently poorly understood in plants, due to a large influence of parameters such as species, cultivar, experimental setup and plant age on the response. In this study, 7-, 10- and 14-day-old Arabidopsis thaliana seedlings were exposed to 96 h and 168 h of 100 mGy h(-1) chronic gamma-radiation in a hydroponic setup. The response of growth, photosynthesis and the transcription of genes involved in DNA repair, cell cycle...

  9. Risk perception, attitudes towards risk and risk management: evidence and implications

    Wauters, Erwin; van Winsen, Frankwin; DE MEY, Yann; Lauwers, Ludwig
    The comprehensive risk analysis of a business such as farming entails questions on what is at stake, how important is the risk concern and how to deal with it. We performed a sequential mixed method, with the in-depth interviews in the first stage (n = 35), followed by a survey on the Flemish FADN (n = 614) in the second, to investigate the farmers' risk perception, the attitudes towards risk and the perceived usefulness of the risk management strategies. We find that, rather than the short-term volatility in prices, the longer term co-evolution of expenses versus receipts is of a...

  10. Exploring the rhizospheric and endophytic bacterial communities of Acer pseudoplatanus growing on a TNT-contaminated soil: towards the development of a rhizocompetent TNT-detoxifying plant growth promoting consortium

    THIJS, Sofie; Van Dillewijn, Pieter; SILLEN, Wouter; TRUYENS, Sascha; HOLTAPPELS, Michelle; D'HAEN, Jan; CARLEER, Robert; WEYENS, Nele; AMELOOT, Marcel; Ramos, Juan-Luis; VANGRONSVELD, Jaco
    Background and aims Numerous microorganisms have been isolated from trinitrotoluene (TNT)-contaminated soils, however TNT tends to persist, indicating that the microbial biomass or activity is insufficient for degradation. Deep-rooting trees at military sites have been found to take-up contaminants from groundwater, and the extensive root and endosphere provide ideal niches for microbial TNT-transformations. Methods We characterised the rhizosphere, root endosphere and endo-phyllosphere bacteria of Acer pseudoplatanus growing at a historically TNT-contaminated location, using 16S rRNA gene fingerprinting, bacteria isolation, oxidoreductase gene-cloning, in planta growth-promotion (PGP) tests, inoculation, plant physiology measurements and microscopy. Results Based on terminal-restriction-fragment-length-polymorphism analysis, bulk soil and...

  11. Soil fungi appear to have a retarding rather than a stimulating role on soil apatite weathering

    SMITS, Mark; Johansson, Leif; Wallander, Hakan
    Aims Vegetation stimulates, in general, soil mineral weathering. It has been hypothesized that plant-associated microorganisms, especially ectomycorrhizal fungi play a major role in this process. We studied apatite dissolution in a vegetation gradient in southern Norway to test the role of ectomycorrhizal vegetation on mineral weathering. Methods A natural occurring lead contamination, probably present since the last glaciation, caused a gradient from bare soil, via sparse grass to healthy spruce forest. We measured apatite content, soil solution chemistry, delta C-13, delta N-15, C, N and ergosterol content in soil profiles along the gradient. Results The apatite loss for each soil...

  12. Azithromycin and the Treatment of Lymphocytic Airway Inflammation After Lung Transplantation

    VOS, Rein; Verleden, S. E.; Ruttens, D.; Vandermeulen, E.; Bellon, H.; Neyrinck, A.; Van Raemdonck, D. E.; Yserbyt, J.; Dupont, L. J.; Verbeken, E. K.; Moelants, E.; Mortier, A.; Proost, P.; Schols, D.; Cox, B.; Verleden, G. M.; Vanaudenaerde, B. M.
    Lymphocytic airway inflammation is a major risk factor for chronic lung allograft dysfunction, for which there is no established treatment. We investigated whether azithromycin could control lymphocytic airway inflammation and improve allograft function. Fifteen lung transplant recipients demonstrating acute allograft dysfunction due to isolated lymphocytic airway inflammation were prospectively treated with azithromycin for at least 6 months (NCT01109160). Spirometry (FVC, FEV1, FEF25-75, Tiffeneau index) and FeNO were assessed before and up to 12 months after initiation of azithromycin. Radiologic features, local inflammation assessed on airway biopsy (rejection score, IL-17(+)cells/mm(2) lamina propria) and broncho-alveolar lavage fluid (total and differential cell counts,...

  13. Left ventricular diastolic function associated with common genetic variation in ATP12A in a general population

    Knez, Judita; Salvi, Erika; Tikhonoff, Valerie; Stolarz-Skrzypek, Katarzyna; Ryabikov, Andrew; Thijs, Lutgarde; Braga, Daniele; Kloch-Badelek, Malgorzata; Malyutina, Sofia; Casiglia, Edoardo; Czarnecka, Danuta; Kawecka-Jaszcz, Kalina; Cusi, Daniele; NAWROT, Tim; Staessen, Jan A.; Kuznetsova, Tatiana
    Background: Left ventricular (LV) function depends on the activity of transmembrane electrolyte transporters. Failing human myocardium has lower Na+/K+ ATPase expression and higher intracellular sodium concentrations. The ATP12A gene encodes a catalytic subunit of an ATPase that can function as a Na+/K+ pump. We, therefore, investigated the association between LV function and common genetic variants in ATP12A. Methods: A random sample of 1166 participants (53.7% women; mean age 49.5 years, 44.8% hypertensive) was recruited in Belgium, Poland, Italy and Russia. We measured transmitral early and late diastolic velocities (E and A) by pulsed wave Doppler, and mitral annular velocities (e'...

  14. Evaluation of the Thickness and Oxygen Transmission Rate before and after Thermoforming Mono- and Multi-layer Sheets into Trays with Variable Depth

    BUNTINX, Mieke; WILLEMS, Gert; KNOCKAERT, Griet; Adons, Dimitri; YPERMAN, Jan; CARLEER, Robert; PEETERS, Roos
    During thermoforming, plastic sheets are heated and subsequently deformed through the application of mechanical stretching and/or pressure. This process directly impacts sheet properties such as material thickness in walls, corners, and bottom, crystallinity in the constituent layers, and particularly the oxygen gas permeability. The aim of this study was to quantify the impact of thermoforming on thickness and oxygen transmission rate (OTR) of selected packaging materials (polypropylene (PP); PP/ethylene-vinyl alcohol co-polymer/PP (PP/EVOH/PP); polystyrene/EVOH/polyethylene (PS/EVOH/PE); amorphous polyethylene terephtalate/PE (APET/PE); APET/PE/EVOH/PE; polyamide/PE (PA/PE); and (PE/)PA/EVOH/PA/PE). These materials were extruded in two different thicknesses and thermoformed into trays with the same top dimensions...

  15. Selectie van rechtsleer verschenen in de periode van 4 mei 2013 tot en met 5 augustus 2013

    VANHEUSDEN, Bernard

  16. Blood pressure changes in association with black carbon exposure in a panel of healthy adults are independent of retinal microcirculation.

    LOUWIES, Tijs; Nawrot, Tim; Cox, Bianca; Dons, Evi; Penders, Joris; PROVOST, Eline; Int Panis, Luc; De Boever, Patrick
    Exposure to ambient particulate matter and elevated blood pressure are risk factors for cardiovascular morbidity and mortality. Microvascular changes might be an important pathway in explaining the association between air pollution and blood pressure. The objective of the study was to evaluate the role of the retinal microcirculation in the association between black carbon (BC) exposure and blood pressure.We estimated subchronic BC exposure based on 1-week personal measurements (μAethalometer, AethLabs) in 55 healthy nurses. Blood pressure and retinal microvasculature were measured on four different days (range: 2–4) during this week.Subchronic BC exposure averaged (± SD) 1334 ± 631 ng/m3 and...

  17. DNA methylation patterns in respiratory allergy cases: comparability of saliva vs. blood

    Langie, Sabine; Traen, Sophie; DE BOEVER, Patrick; Szic, Katarzyna Szarc Vel; Declerck, Ken; Koppen, Gudrun; Schepers, Anne; Van Camp, Guy; Vanden Berghe, Wim; Schoeters, Greet

  18. A medical image-based graphical platform-Features, applications and relevance for brachytherapy

    Fonseca, Gabriel P.; RENIERS, Brigitte; Landry, Guillaume; White, Shane; Bellezzo, Murillo; Antunes, Paula C.G.; de Sales, Camila P.; Welteman, Eduardo; Yoriyaz, Helio; Verhaegen, Frank
    PURPOSE: Brachytherapy dose calculation is commonly performed using the Task Group-No 43 Report-Updated protocol (TG-43U1) formalism. Recently, a more accurate approach has been proposed that can handle tissue composition, tissue density, body shape, applicator geometry, and dose reporting either in media or water. Some model-based dose calculation algorithms are based on Monte Carlo (MC) simulations. This work presents a software platform capable of processing medical images and treatment plans, and preparing the required input data for MC simulations. METHODS AND MATERIALS: The A Medical Image-based Graphical platfOrm Brachytherapy module (AMIGOBrachy) is a user interface, coupled to the MCNP6 MC code,...

  19. Potential of life cycle assessment to support environmental decision making at commercial dairy farms

    Meul, Marijke; Van Middelaar, Corina E.; de Boer, Imke J. M.; VAN PASSEL, Steven; Fremaut, Dirk; Haesaert, Geert
    In this paper, we evaluate the potential of life cycle assessment (LCA) to support environmental decision making at commercial dairy farms. To achieve this, we follow a four-step method that allows converting environmental assessment results using LCA into case-specific advice for farmers. This is illustrated in a case-study involving 20 specialized Flemish dairy farms. Calculated LCA indicators are normalized into scores between 0 and 100, whereby a score of 100 is assumed optimal, to allow for a mutual comparison of indicators for different environmental impact categories. Next, major farm and management characteristics affecting environmental performance are identified using multiple regression...

  20. Biomass: hot or not? Extended techno-economic assessment of Energy Conversion Parks

    VAN DAEL, Miet
    Biomass is one of the most versatile sources of renewable energy and essential in attaining the 20-20-20 targets imposed by Europe. Biomass allows producing biofuels, electricity and heat. Besides, one can produce high value products from biomass, such as chemicals. However, for these purposes it is important to use biomass residue streams which are nowadays not or inefficiently used. As such, it is possible to avoid competition with food or feed. Next to the advantages such as versatility, biomass also has some disadvantages: it is often geographically dispersed, waste streams have a high moisture content, low energy density, and biomass...

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