Center for Environmental Research

Leipzig, Germany

Center for Environmental Research

Leipzig, Germany
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Tulpule K.,University of Bremen | Tulpule K.,Center for Environmental Research | Dringen R.,University of Bremen | Dringen R.,Center for Environmental Research | Dringen R.,Monash University
GLIA | Year: 2012

Formaldehyde is a neurotoxic compound that can be endogenously generated in the brain. Because astrocytes play a key role in metabolism and detoxification processes in brain, we have investigated the capacity of these cells to metabolize formaldehyde using primary astrocyte-rich cultures as a model system. Application of formaldehyde to these cultures resulted in the appearance of formate in cells and in a time-, concentration- and temperature-dependent disappearance of formaldehyde from the medium that was accompanied by a matching extracellular accumulation of formate. This formaldehyde-oxidizing capacity of astrocyte cultures is likely to be catalyzed by alcohol dehydrogenase 3 and aldehyde dehydrogenase 2, because the cells of the cultures contain the mRNAs of these formaldehyde-oxidizing enzymes. In addition, exposure to formaldehyde increased both glucose consumption and lactate production by the cells. Both the strong increase in the cellular formate content and the increase in glycolytic flux were only observed after application of formaldehyde to the cells, but not after treatment with exogenous methanol or formate. The accelerated lactate production was not additive to that obtained for azide, a known inhibitor of complex IV of the respiratory chain, and persisted after removal of formaldehyde after a formaldehyde exposure for 1.5 h. These data demonstrate that cultured astrocytes efficiently oxidize formaldehyde to formate, which subsequently enhances glycolytic flux, most likely by inhibition of mitochondrial respiration. © 2012 Wiley Periodicals, Inc.

Esther A.,University of Potsdam | Esther A.,Federal Research Center for Cultivated Plants | Groeneveld J.,Center for Environmental Research | Groeneveld J.,University of Auckland | And 7 more authors.
Journal of Vegetation Science | Year: 2010

Question: The majority of studies investigating the impact of climate change on local plant communities ignores changes in regional processes, such as immigration from the regional seed pool. Here we explore: (i) the potential impact of climate change on composition of the regional seed pool, (ii) the influence of changes in climate and in the regional seed pool on local community structure, and (iii) the combinations of life history traits, i.e. plant functional types (PFTs), that are most affected by environmental changes. Location: Fire-prone, Mediterranean-type shrublands in southwestern Australia. Methods: Spatially explicit simulation experiments were conducted at the population level under different rainfall and fire regime scenarios to determine the effect of environmental change on the regional seed pool for 38 PFTs. The effects of environmental and seed immigration changes on local community dynamics were then derived from community-level experiments. Classification tree analyses were used to investigate PFT-specific vulnerabilities to climate change. Results: The classification tree analyses revealed that responses of PFTs to climate change are determined by specific trait characteristics. PFT-specific seed production and community patterns responded in a complex manner to climate change. For example, an increase in annual rainfall caused an increase in numbers of dispersed seeds for some PFTs, but decreased PFT diversity in the community. Conversely, a simulated decrease in rainfall reduced the number of dispersed seeds and diversity of PFTs. Conclusions: PFT interactions and regional processes must be considered when assessing how local community structure will be affected by environmental change. © 2010 International Association for Vegetation Science.

Kespohl S.,Ruhr University Bochum | Kotschy-Lang N.,Berufsgenossenschaftliche Klinik fur Berufskrankheiten | Tomm J.M.,Center for Environmental Research | Von Bergen M.,Center for Environmental Research | And 3 more authors.
International Archives of Allergy and Immunology | Year: 2012

Allergic reactions to wood dust allergens are rare, and only few in vitro diagnostic tools and information about relevant allergens are available. To differentiate between protein-based allergy and probably clinically silent glycogenic sensitization, it is helpful to characterize the relevant protein allergens and specify IgE binding. The current case report deals with the occupational softwood allergy of a carpenter exposed to different wood dusts. Skin tests and IgE tests against wood were performed with specifically tailored ImmunoCAPs and cross-reactive carbohydrate determinants. Potential allergens were identified by IgE blots and tandem mass spectrometry. The clinical relevance was verified by challenge tests. Specific IgE to softwood (spruce, pine and larch wood), beech wood, natural rubber latex (NRL) and horseradish peroxidase (HRP) were detected. Allergens in spruce wood, the dominant allergen source, were identified as peroxidases. Softwood were the strongest inhibitors. HRP reduced IgE binding to softwood to <50%, indicating predominantly proteinogenic epitopes, whereas IgE binding to NRL and beech wood was reduced to >50% by HRP, indicating predominantly glycogenic IgE epitopes. Skin and challenge tests underlined that softwoods were the source of sensitization. For the polysensitized patient, a clinically relevant softwood allergy was diagnosed, not only by challenge tests but also with specifically tailored in vitro tools. © 2011 S. Karger AG, Basel.

Widiatmaka,Bogor Agricultural University | Ambarwulan W.,Geospatial Information Agency | Setiawan Y.,Center for Environmental Research | Walter C.,Agrocampus Ouest
Applied and Environmental Soil Science | Year: 2016

Indonesian food production depends highly on Java Island,which holds themost fertile soils in the country but had limited area.The objective of the research was to analyse the availability of suitable land for agriculture in Tuban Regency, an agricultural regency in Java Island. Land suitability was evaluated with spatial multicriteria analysis, integrating soil order, land capability, elevation, slope, slope direction, land use/land cover, accessibility, and climate. Land availability was analysed, integrating the forest area status designation and the spatial pattern of regional official land use plan.The results indicated that suitable land for agriculture corresponds to 91% of the total study area, confirming the high soil fertility. Analysis of land availability then indicated that 18% of the areawas both suitable and available for agriculture.Considering the actual land utilization, the future development of agriculture in the region has less than 7% of the land area left for agricultural expansion.The overall results showed the importance of looking for land allocated for agriculture outside Java Island to anticipate the need for food of a country with a high population growth rate and also developing planning for food production. Copyright © 2016 Widiatmaka et al.

Wania F.,University of Toronto | Lei Y.D.,University of Toronto | Wang C.,University of Toronto | Abbatt J.P.D.,University of Toronto | And 2 more authors.
Atmospheric Chemistry and Physics | Year: 2015

Many atmospheric and chemical variables influence the partitioning equilibrium between gas phase and condensed phases of compounds implicated in the formation of secondary organic aerosol (SOA). The large number of factors and their interaction makes it often difficult to assess their relative importance and concerted impact. Here we introduce a two-dimensional space which maps regions of dominant atmospheric phase distribution within a coordinate system defined by equilibrium partition coefficients between the gas phase, an aqueous phase and a water-insoluble organic matter (WIOM) phase. Placing compounds formed from the oxidation of n-alkanes, terpenes and mono-aromatic hydrocarbons on the maps based on their predicted partitioning properties allows for a simple graphical assessment of their equilibrium phase distribution behaviour. Specifically, it allows for the simultaneous visualisation and quantitative comparison of the impact on phase distribution of changes in atmospheric parameters (such as temperature, salinity, WIOM-phase polarity, organic aerosol load, and liquid water content) and chemical properties (such as oxidation state, molecular size, functionalisation, and dimerisation). The graphical analysis reveals that the addition of hydroxyl, carbonyl and carboxyl groups increases the affinity of aliphatic, alicyclic and aromatic hydrocarbons for the aqueous phase more rapidly than their affinity for WIOM, suggesting that the aqueous phase may often be relevant even for substances that are considerably larger than the C2 and C3 compounds that are typically believed to be associated with aqueous SOA. In particular, the maps identify some compounds that contribute to SOA formation if partitioning to both WIOM and aqueous phase is considered but would remain in the gas phase if either condensed phase were neglected. For example, many semi-volatile α-pinene oxidation products will contribute to aqueous SOA under the conditions of high liquid water content encountered in clouds but would remain vapours in wet aerosol. It is conceivable to develop parameterisations of "partitioning basis sets" that group compounds with comparable partitioning properties, which-when combined with data on the abundance of those groups of compounds-could serve in the simulation of SOA formation. © 2015 Author(s).

Wahyuningsih S.,Kampus IPB Dramaga | Effendi H.,Center for Environmental Research | Wardiatno Y.,Kampus IPB Dramaga
AACL Bioflux | Year: 2015

Nitrogen wastes in the culture system are still difficult to handle. Aquaponic system can be an alternative to reduce the impact of the inorganic nitrogen accumulation that can be a limiting factor to the fish growth. At aquaponic system plant can absorb nutrient from farming waste, whereas bacteria functions in reducing the ammonia through the nitrification process. The aim of study was to assess aquaculture nitrogen waste reduction in aquaponic system. The result showed that the nutrient concentration fluctuated during the observation periods, and the highest nutrients accumulation were 6.489, 3.601, and 0.933 mg L-1 for TAN (ammonia and ammonium), nitrate, and nitrite in the control, respectively. Integration of tilapia (Oreochromis niloticus) fish farming, romaine lettuce (Lactuca sativa), and bacteria can reduce inorganic nitrogen with the best removal efficiency. There was 91.50, 34.41, 22.86, and 49.74% for TAN, nitrate, and nitrite, respectively. All results showed that treatment with the bacteria addition was the best treatment to reduce nitrogen waste, optimizing the fish and romaine lettuce plants production. © 2015, BIOFLUX SRL. All rights resereved.

Norouzi P.,University of Tehran | Rashedi H.,University of Tehran | Alipour A.,University of Tehran | Faridbod F.,Tehran University of Medical Sciences | And 2 more authors.
International Journal of Electrochemical Science | Year: 2011

Flurazepam is a benzodiazepine derivative which possesses anxiolytic, anticonvulsant, sedative and skeletal muscle relaxant properties. This research introduces two kinds of PVC membrane sensor (symmetric and asymmetric) for determination of flurazepam (FLZ) in pharmaceutical formulation. For the membrane preparation, flurazepam-tetraphenyl borate ion-pair was employed as a sensing material in the PVC membrane. Several plasticizers were studied in the membrane composition dibutyl phthalate (DBP), acetophenon (AP), nitrobenzene (NB) and nitrophenyloctyl ether (o-NPOE). After a series of experiments, the best electrode performance was made of a membrane composed of DBP. The electrodes illustrated a fast, stable and Nernstian response over a wide flurazepam concentration range of 1×10-5 to 1×10-2 M in case of PVC membrane electrode and 1×10-6 to 1×10-3 M in case of wire coated electrode, in the pH range of 4.0-7.0. Validation of the method shows suitability of the sensors for use in the analysis of flurazepam hydrochloride in pharmaceutical formulation. © 2011 by ESG.

Ost M.,Novia University of Applied Sciences | Lehikoinen A.,University of Helsinki | Jaatinen K.,Novia University of Applied Sciences | Kilpi M.,Center for Environmental Research
Oecologia | Year: 2011

The potentially confounded effects of factors affecting breeding dispersal have rarely been simultaneously examined. The consequences of breeding dispersal are even less studied, presenting a paradox: breeding dispersal seldom seems to improve breeding success, despite its presumed adaptiveness. We studied the causes and consequences of breeding dispersal in female-philopatric eiders (Somateria mollissima) in relation to the spatiotemporal predictability of nest success. Previous nest fate, breeding experience, and breeding density simultaneously affected breeding dispersal. Dispersal distances were longer among inexperienced breeders and after failed breeding. Individual dispersal distances decreased with increasing nest-site-specific breeding density, whereas island-specific nesting success peaked at intermediate densities. The fate of neighbouring nests ('public information') did not influence dispersal. Breeding dispersal was unrelated to subsequent hatching success, controlling for individual quality (body condition, breeding experience, previous nest fate), while it delayed hatch date, which is likely to impair reproductive success. This delay may result from the loss of acquired information of local breeding conditions, prolonging nest prospecting and establishment, also helping explain why breeding dispersal did not increase at high breeding densities, despite a potential reduction in nesting success. In long-lived species, however, dispersal-induced reductions in reproductive output in one season could be offset by improved parental survival prospects. Careful nest prospecting may be profitable, because overall nest success had a strong island-specific component but showed weak temporal variation, and successive individual nest fates were predictable between years. Once a safe nest site is found, females may breed at the same place successfully for many years. © 2010 Springer-Verlag.

Urrutia R.,University of Concepción | Araneda A.,University of Concepción | Torres L.,University of Concepción | Cruces F.,University of Concepción | And 5 more authors.
Hydrobiologia | Year: 2010

A sediment core encompassing the last 2000 years was extracted from Lake Laja, Chile, (36°54′S, 71°05′W) using an Uwitec drilling platform. The sediment was subsampled for loss on ignition, nutrients, biogenic silica, and biological proxies (diatoms, chironomids, pollen). The sedimentary profile was characterized by several coarse volcanic layers. Loss on ignition, nutrients, and biogenic silica showed an increasing trend that suggests a recent shift to a higher trophic status. Diatom assemblages also suggested higher nutrient content with increased abundances of Aulacoseira granulata, A. distans, and Asterionella formosa. At the same time, a marked change in the benthic and facultative planktonic taxa may be associated with cooling. This period of change coincides with the European Little Ice Age (LIA). The chironomid profile showed four key zones distinguished largely by changes in the abundance of Tanytarsini, Parachironomus, and Macropelopia. Like diatoms, chironomids also seemed to reflect a shift to higher trophic conditions in the upper part reflected by increasing abundance of taxa such as Tribelos/Phaenopsectra, Cricotopus/Orthocladius, and Ablabesmyia. The most striking feature in the chironomid assemblage is the abundance of Podonominae, Parapsectrocladius, and Limnophyes/Compterosmittia, which could be associated with a cold-dry period between 1500 and 1900 AD in Lake Laja (the period of the European LIA). Pollen assemblages indicated fluctuations in humidity through changes in Nothofagus dombeyi-type, Poaceae, and Ephedra, and we inferred a strong human impact over the last 100 years from the appearance of Plantago and increased levels of Poaceae and Asteraceae subf. Cichorioidae. Finally, the three proxies showed the occurrence of a cold-dry event in Lake Laja (~1550-1900 AD), which roughly coincides with the European LIA. However the data from this research, does not prove neither rejects the existence of the occurrence of the MWP in the central Andes. © 2010 Springer Science+Business Media B.V.

Kazmierczak M.,Center for Environmental Research | Wiegand T.,Center for Environmental Research | Huth A.,Center for Environmental Research
Ecological Modelling | Year: 2014

Tropical forests are vital ecosystems which provide numerous ecological functions and forest models can be used to simulate their dynamics. However, due to the high species diversity of tropical forests and the common lack of detailed knowledge about these species, simulating the behavior of each species separately is not feasible. Therefore, species with common characteristics are usually aggregated into species groups. Although the number of species groups is likely to be an important characteristic of forest models, little research has been done on its effect on the results of the model. In this article, we compare the effect of the number of species groups using a physiological forest gap model and review our results using 28 years of field data from a 50. ha forest plot in Panama as well as a chronosequence over four centuries from the same area. The number of simulated groups ranged from 1 to 4, 9 and 16. The parameterization with a single species group is a "neutral" parameterization with all simulated trees being ecophysiologically identical. The number of groups turned out to be an important characteristic of the model which influences its results on a fundamental level. Steady-states characteristics of forests like stem-numbers and stem-size distributions can be successfully simulated with even a single species group while modeling the long-term dynamics requires a higher number of groups. On the downside, a higher number of groups makes parameterization and fitting of the model more difficult. We conclude that the number of species groups is a vital characteristic of a forest model which has far-reaching consequences for its results and needs to be chosen with care. © 2014 Elsevier B.V.

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