Document Server@UHasselt
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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.
Mostrando recursos 1 - 19 de 19
1.
Bioenergy to save the world - Producing novel energy plants for growth on abandoned land - Schroder, P; Herzig, R; Bojinov, B; RUTTENS, Ann; Nehnevajova, E; Stamatiadis, S; Memon, A; VassileV, A; Caviezel, M; VANGRONSVELD, Jaco
Background and Aim. Following to the 2006 climate summit, the European Union formally set the goal of limiting global warming to 2 degrees Celsius. But even today, climate change is already affecting people and ecosystems. Examples are melting glaciers and polar ice, reports about thawing permafrost areas, dying coral reefs, rising sea levels, changing ecosystems and fatal heat periods. Within the last 150 years, CO2 levels rose from 280 ppm to currently over 400 ppm. If we continue on our present course, CO2 equivalent levels could approach 600 ppm by 2035. However, if CO2 levels are not stabilized at the...
2.
Normalisation of real-time RT-PCR gene expression measurements in Arabidopsis thaliana exposed to increased metal concentrations - REMANS, Tony; SMEETS, Karen; OPDENAKKER, Kelly; MATHIJSEN, Dennis; VANGRONSVELD, Jaco; CUYPERS, Ann
Accurate quantification by real-time RT-PCR relies on normalisation of the measured gene expression data. Normalisation with multiple reference genes is becoming the standard, but the best reference genes for gene expression studies within one organism may depend on the applied treatments or the organs and tissues studied. Ideally, reference genes should be evaluated in all experimental systems. A number of candidate reference genes for Arabidopsis have been proposed, which can be used as a starting point to evaluate their expression stability in individual experimental systems by available computer algorithms like geNorm and NormFinder. Using this approach, we identified the best...
3.
Cadmium phytoextraction: present state, biological interactions and research needs - Vassilev, A.; VANGRONSVELD, Jaco; Yordanov, I.
Cadmium is a toxic metal for living organisms and an environmental
contaminant. Agricultural soils in many parts of the world are slightly
to moderately contaminated by Cd due to long term use of phosphatic fertilisers,
sewage sludge application as well as smelter dust spreading. Cd phytoextraction
is a promising and environmentally friendly approach for soil decontamination.
Plant potential for Cd extraction generally depends on shoot Cd
concentration and shoot biomass yield. Some ecotypes of the metal hyperaccumulator
species Thlaspi caerulescens J. & C. Presl possess an extraordinary
Cd accumulation and tolerance, but have low biomass yield. Some fast growing
trees (Salix, Populus) and high biomass producing crops (Brassica, Helianthus,
Nicotiana)...
4.
Nutrient uptake by intact mycorrhizal Pinus sylvestrisseedlings: a diagnostic tool to detect copper toxicity - VAN TICHELEN, Katia; Vanstraelen, T.; COLPAERT, Jan
We developed a nondestructive method for detecting early toxic effects of sublethal copper (Cu) concentrations on ectomycorrhizal and non-mycorrhizal (NM) Scots pine (Pinus sylvestris L.) seedlings. The fungal symbionts examined were Paxillus involutus (Fr.) Pr, Suillus luteus (Fr.) S.F. Cray and Thelephora terrestris (Ehrh.) Fr. The accumulation of Cu in needles and fungal development (ergosterol) in roots and substrate were assessed. Inorganic phosphate (P-i) and ammonium (NH4+) uptake capacities were determined in a semi-hydroponic cultivation system on intact P-limited plants that were exposed for 3 weeks to 0.32 (control), 8 or 16 mu M Cu2+ Short-term effects of a 1-hour...
5.
Nickel-Resistance-Based Minitransposons: New Tools for Genetic Manipulation of Environmental Bacteria - Taghavi, S.; Delanghe, H.; LODEWYCKX, Cindy; Mergeay, M.; VAN DER LELIE, Daniel
The ncc and nre nickel resistance determinants from Ralstonia eutropha-like strain 31A were used to construct mini-Tn5 transposons. Broad host expression of nickel resistance was observed for the nre minitransposons in members of the ?, ?, and ? subclasses of the Proteobacteria, while the ncc minitransposons expressed nickel resistance only in R. eutropha-like strains.
6.
ENDOPHYTIC BACTERIA FROM SEEDS OF NICOTIANA TABACUM CAN REDUCE CADMIUM PHYTOTOXICITY - Mastretta, Chiara; Taghavi, Safiyh; van der Lelie, Daniel; Mengoni, Alessio; Galardi, Francesca; Gonnelli, Christina; Barac, Tanja; Boulet, Jana; Weyens, Nele; Vangronsveld, Jaco
Although endophytic bacteria seem to have a close association with their host plant, little is known about the influence of seed endophytic bacteria on initial plant development and on their interactions with plants under conditions of metal toxicity. In order to further elucidate this close relationship, we isolated endophytic bacteria from surface sterilized Nicotiana tabacum seeds that were collected from plants cultivated on a cadmium-(Cd) and zinc-enriched soil. Many of the isolated strains showed Cd tolerance. Sterilely grown tobacco plants were inoculated with either the endogenous microbial consortium, composed of cultivable and noncultivable strains; single strains; or defined consortia of...
8.
Cadmium-Related Mortality and Long-Term Secular Trends in the Cadmium Body Burden of an Environmentally Exposed Population - Nawrot, Tim; Van Hecke, Etienne; Thijs, Lutgarde; Richart, Tom; Kuznetsova, Tatiana; Jin, Yu; Vangronsveld, Jaco; Roels, Harry A.; Staessen, Jan A.
BACKGROUND: Few population studies have reported on the long-term changes in the internal cadmium dose and simultaneously occurring mortality. OBJECTIVE: We monitored blood cadmium (BCd), 24-hr urinary cadmium (UCd), and mortality in an environmentally exposed population. METHODS: Starting from 1985, we followed BCd (until 2003), UCd (until 1996), and mortality (until 2007) among 476 and 480 subjects, randomly recruited from low- exposure areas (LEA) and high-exposure areas (HEA). The last cadmium-producing plant in the HEA closed in 2002. RESULTS: From 1985-1989 to 1991-1996, BCd decreased by 40.3% and 18.9% in the LEA and HEA, respectively (p < 0.0001 for between-area...
9.
Longkankerrisico en blootstelling aan cadmium via het milieu : antwoord op de kritiek met toetsing van de causaliteit - NAWROT, Tim; Roels, H.; Thijs, L.; VANGRONSVELD, Jaco; Richart, T.; Van Hecke, E.; Staessen, J.
Wij onderzochten of het risico van longkanker in verband staat met blootstelling aan cadmium via het leefmilieu.
Daartoe werden 994 personen gerekruteerd door middel van een aselecte steekproef in gebieden met
een hoge en een lage blootstelling aan cadmium. In de periode 1985-1989 maten wij bij deze proefpersonen
de hoeveelheid cadmium die gedurende 24 uur via de urine werd uitgescheiden (een index van de
levenslange blootstelling), evenals de cadmiumconcentratie in de bodem van hun moestuintjes. We volgden
de cohorte tot oktober 2004.
De cadmiumconcentratie in de bodem had een bereik van 0,8 tot 17,0 mg/kg. De gemiddelde cadmiumuitscheiding
gedurende 24 uur bedroeg 12,3 nmol bij de proefpersonen...
10.
Tolerance of two hydroponically grown Salix genotypes to excess zinc - Vassillev, Andon; PEREZ-SANC, Araceli; CUYPERS, Ann; VANGRONSVELD, Jaco
Woody cuttings from two Salix genotypes (genotype I-clone LUC-3 1, Salix alba and genotype II- clone STOTT, Salix viminalis) were grown hydroponically for 14 days at increasing concentrations of Zn: control, 50, 100 or 150 AM Zn. Genotype tolerance to excess zinc (Zn) was evaluated using a root elongation test. The changes in growth, Zn, iron (Fe), copper (Cu) and manganese (Mn) concentrations as well as photosynthetic performance were used as additional evaluation criteria. Photosynthetic pigments concentrations in Zn-exposed cuttings of genotype II decreased as compared with genotype I, which corresponded well with the higher leaf Zn accumulation, decreased Fe...
11.
Critical evaluation and statistical validation of a hydroponic culture system for Arabidopsis thaliana - SMEETS, Karen; RUYTINX, Jos; VAN BELLEGHEM, Frank; SEMANE, Brahim; LIN, Dan; VANGRONSVELD, Jaco; CUYPERS, Ann
Arabidopsis thaliana is one of the most widely used model organisms in plant sciences. Because of the increasing knowledge in the understanding of its molecular pathways, a reproducible and stable growth set-up for obtaining uniform plants becomes more important. In order to be able to easily harvest and study both roots and shoots, and to allow simple exposure to water-soluble toxic substances, a hydroponic system is the desired cultivation method for controlled plant growth. Based on earlier developed hydroponic cultivation protocols, a hydroponic set-up was optimized and statistically validated using linear mixed-effects models. In order to determine important components that...
12.
Assessing farm sustainability with value oriented methods - VAN PASSEL, Steven
Agricultural policy makers aim to combine strong economic performance with a sustainable use of natural resources. An important step is to move from trying to define sustainability towards developing concrete tools for measuring and promoting achievements in sustainability. Hence, sustainability assessment is inevitably based on strong simplifications both of the theoretical paradigm and of the characteristics of systems of concern. The most known approaches to assess sustainability performance are burden orientated: they assess the costs or potential harm of resource use. These burden-oriented approaches focus on the level of environmental impacts caused by an economic activity compared to another set...
13.
Exploring production-theoretical insights for economic-ecological trade-off analysis - Van Meensel, J; Lauwers, L; Van Huylenbroeck, G; VAN PASSEL, Steven
This paper provides a framework for analyzing economic-ecological trade-off measures at firm level. This must allow for distinguishing different stages in the trade-off curve. Based on a literature review, various economic-ecological trade-off paradigms and theories are combined, and integrated and additive measures are distinguished. While integrated measures address inputoutput transformation and the relation with negative externalities and profit generation, additive measures aim at pollution abatement after externalities have already been generated. Since additive measures are costly, they always imply a negative trade-off, improving ecological performance and diminishing economic performance. Some integrated measures imply a positive trade-off, improving both economic and...
14.
Can Cleantech contribute to a sustainable future? - VAN PASSEL, Steven
Cleantech can be described as a diverse range of products, services or processes using technologies that optimize our use of natural resources and minimize environmental impacts. In this paper we explain that Cleantech can be seen as an implementation towards (weak) sustainability. This because proponents of weak sustainability believe that technological improvement can overcome any resource constraint. Cleantech can contribute towards a sustainable future but Cleantech is not the equivalent of a sustainable future because Cleantech activities do not solve the question of absolute scarcity. On the other hand, Cleantech can be an important step if we move from system...
15.
Differences in metal sequestration between zebra mussels from clean and polluted field locations - Voets, Judith; STEEN REDEKER, Erik; Blust, Ronny; Bervoets, Lieven
Organisms are able to detoxify accumulated metals by, e.g. binding them to metallothionein (MT) and/or sequestering them in metal-rich granules (MRG). The different factors involved in determining the capacity or efficiency with which metals are detoxified are not yet known. In this work we studied how the sub-cellular distribution pattern of cadmium, copper and zinc in whole tissue of zebra mussels from clean and polluted surface waters is influenced by the total accumulated metal concentration and by its physiological condition. Additionally we measured the metallothionein concentration in the mussel tissue. Metal concentration increased gradually in the metal-sensitive and detoxified sub-cellular...
16.
Sustainable value assessment of farms using frontier efficiency benchmarks - VAN PASSEL, Steven; Van Huylenbroeck, Guido; Lauwers, Ludwig; Mathijs, Erik
Appropriate assessment of firm sustainability facilitates actor-driven processes towards sustainable development. The methodology in this paper builds further on two proven methodologies for the assessment of sustainability performance: it combines the sustainable value approach with frontier efficiency benchmarks. The sustainable value methodology tries to relate firm performance to the use of different resources. This approach assesses contributions to corporate sustainability by comparing firm resource productivity with the resource productivity of a benchmark, and this for all resources considered. The efficiency is calculated by estimating the production frontier indicating the maximum feasible production possibilities. In this research, the sustainable value approach...
17.
The detrimental health effects of traffic-related air pollution: a role for DNA methylation? - NAWROT, Tim; Adcock, Ian
Exposure to air pollution and particularly that from diesel engines has been known for many years to affect asthma symptoms and hospitalizations (1) as well as all-cause (2) and cardiovascular mortality (3). Indeed, it has been shown that 2 hours of walking in shopping areas with high levels of diesel fumes (Oxford Street, London) containing ultrafine particles and elemental carbon can result in a significant loss of lung function and an increase in inflammatory mediators (4). Such changes were rapid and prolonged with a return to normal lung function occurring between 5 and 22 hours. The effect of chronic exposure...
18.
Phytoremediation: plant-endophyte partnerships take the challenge Phytoremediation: plant-endophyte partnerships take the challenge - WEYENS, Nele; Van der Lelie, D.; Taghavi, S.; VANGRONSVELD, Jaco
A promising field to exploit plant-endophyte partnerships is the remediation of contaminated soils and (ground) water. Many plant growth promoting endophytes can assist their host plant to overcome contaminant-induced stress responses, thus providing improved plant growth. During phytoremediation of organic contaminants, plants can further benefit from endophytes possessing appropriate degradation pathways and metabolic capabilities, leading to more efficient contaminant degradation and reduction of both phytotoxicity and evapotranspiration of volatile contaminants. For phytoremediation of toxic metals, endophytes possessing a metal-resistance/sequestration system can lower metal phytotoxicity and affect metal translocation to the above-ground plant parts. Furthermore, endophytes that can degrade organic contaminants...
19.
House dust as possible route of environmental exposure to cadmium and lead in the adult general population - Hogervorst, Janneke; PLUSQUIN, Michelle; VANGRONSVELD, Jaco; Nawrot, Tim; CUYPERS, Ann; Van Hecke, Etienne; Roels, Harry; CARLEER, Robert; Staessen, Jan
Contaminated soil particles and food are established routes of exposure. We investigated the relations between biomarkers of exposure to cadmium and lead, and the metal loading rates in house dust in the adult residents of an area with a soil cadmium concentration of >= 3 mg/kg (n = 268) and a reference area (n = 205). We determined the metal concentrations in house dust allowed to settle for 3 months in Petri dishes placed in the participants' bedrooms. The continuously distributed vegetable index was the first principal component derived from the metal concentrations in six different vegetables. The biomarkers of...
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