An optimised sequential extraction scheme for the evaluation of vanadium mobility in soils

Reviewing the current state of knowledge about sequential extraction applied for soil vanadium(V) fractionation, we identified an urgent requirement of an sequential extraction(SE) specified for V. Namely, almost all previous SE extracted only 8.4%–48% of total V in soils(excluding residue). Thus, we proposed an eight-step SE for V fractionation in soils according to the knowledge gained from literature and our own dissolution experiments with model minerals. After extracting the mobilisable and adsorbed V with de-ionised water and 5 mmol/L phosphate, 1 mol/L pyrophosphate was applied to gather organic matter bound V which minimised the artefact dissolving Al and Fe(hydr)oxides occurred when using HNO_3–H_2O_2for extraction. Extraction with 0.4 mol/L NH_2OH·HCl was highly selective toward manganese oxides. Fractionation of different crystalline Al and Fe(hydr)oxides associated V with 1 mol/L HCl, 0.2 mol/L oxalate buffer and 4 mol/L HCl at 95°C especially improved the extractability of V incorporated with crystalline phase associated V. The suitability of our new SE scheme was confirmed by its higher selectivity against the target phases and higher extraction efficiencies(55%–77% of total V) with model minerals and 6 soils of different properties than previous SE.     

Das Pinealorgan der Wirbeltiere: ein Modell für Untersuchungen von Rezeptor-und Effektormechanismen in neuronalen Systemen

Cell and molecular biological investigations have greatly contributed to our understanding of receptor and effector mechanisms in sensory, neuronal, and endocrine cells. A fascinating aspect of this line of research is how such mechanisms have evolved and how they interact with each other. As shown in this contribution, the vertebrate pineal organ is an interesting model to study these problems, because it undergoes a conspicuous transformation during phylogeny, comprises two well-chraracterized receptor mechanisms (photoreception and adrenoreception), and acts upon its targets via neuronal and neuroendocrine signals.

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Herrn Professor Dr. Drs. h. c. A. Oksche zum 65. Geburtstag gewidnet     

Soil hydraulic response to land-use change associated with the recent soybean expansion at the Amazon agricultural frontier

Clearing for large-scale soy production and the displacement of cattle-breeding by soybeans are major features of land-use change in the lowland Amazon that can alter hydrologic properties of soils and the runoff generation over large areas. We measured infiltrability and saturated hydraulic conductivity (Ksat) under natural forest, pasture, and soybeans on Oxisols in a region of rapid soybean expansion in Mato Grosso, Brazil. The forest-pasture conversion reduced infiltrability from 1258 to 100 mm/h and Ksat at all depths. The pasture-soy conversion increased infiltrability from 100 to 469 mm/h (attributed to shallow disking), did not affect Ksat at 12.5 cm, but decreased Ksat at 30 cm from 122 to 80 mm/h, suggesting that soybean cultivation enhances subsoil compaction. Permeability decreased markedly with depth under forest, did not change under pasture, and averaged out at one fourth the forest value under soybeans with a similar pattern of anisotropy. Comparisons of permeability with rainfall intensities indicated that land-use change did not alter the predominantly vertical water movement within the soil. We conclude that this landscape is well buffered against land-use changes regarding near-surface hydrology, even though short-lived ponding and perched water tables may occur locally during high-intensity rainfall on pastures and under soybeans.     

The impact of iron limitation on the physiology of the Antarctic diatom Chaetoceros simplex

Iron availability strongly governs the growth of Southern Ocean phytoplankton. To investigate how iron limitation affects photosynthesis as well as the uptake of carbon and iron in the Antarctic diatom Chaetoceros simplex, a combination of chlorophyll a fluorescence measurements and radiotracer incubations in the presence and absence of chemical inhibitors was conducted. Iron limitation in C. simplex led to a decline in growth rates, photochemical efficiency and structural changes in photosystem II (PSII), including a reorganisation of photosynthetic units in PSII and an increase in size of the functional absorption cross section of PSII. Iron-limited cells further exhibited a reduced plastoquinone pool and decreased photosynthetic electron transport rate, while non-photochemical quenching and relative xanthophyll pigment content were strongly increased, suggesting a photoprotective response. Additionally, iron limitation resulted in a strong decline in carbon fixation and thus the particulate organic carbon quotas. Inhibitor studies demonstrated that, independent of the iron supply, carbon fixation was dependent on internal, but not on extracellular carbonic anhydrase activity. Orthovanadate more strongly inhibited iron uptake in iron-limited cells, indicating that P-type ATPase transporters are involved in iron uptake. The stronger reduction in iron uptake by ascorbate in iron-limited cells suggests that the re-oxidation of iron is required before it can be taken up and further supports the presence of a high-affinity iron transport pathway. The measured changes to photosystem architecture and shifts in carbon and iron uptake strategies in C. simplex as a result of iron limitation provide evidence for a complex interaction of these processes to balance the iron requirements for photosynthesis and carbon demand for sustained growth in iron-limited waters.     

Comparative analysis of socio-economic and environmental performances for Chinese EIPs: case studies in Baotou, Suzhou, and Shanghai

To decouple economic growth from environmental degradation, the Chinese government proposed the circular economy (CE) strategy as part of its 11th 5-Year Plan. This strategy expands the application of CE from individual enterprises to eco-industrial parks (EIPs) and to the cities, provinces, and regions. We carried out field studies in three EIPs in Baotou, Suzhou, and Shanghai. In this paper, we discuss the current state of CE and the sustainable development of EIPs in China. We first provide detailed information on the three EIPs' infrastructures, preferential policies, CE frameworks, and eco-chains. We then examine the status of sustainable development in the three EIPs from the perspectives of socio-economic, resource and material efficiency, and environmental performance. The results indicate that the overall performance of the three EIPs is reasonably good with respect to socio-economics, resources and materials, and efficiency and environmental protection, whereas green management is rather weak and thus requires further improvement. We found that the CE frameworks along with eco-chains within the EIPs are effectively improving resource and material efficiency. Moreover, we demonstrate that there are positive associations among socio-economic, resource and material, and environmental indicators. Given the large presence of EIPs in the local economies, these results suggest that EIPs play a key role in promoting sustainable development in China.     

Sample preparation and biomass determination of SRF model mixture using cryogenic milling and the adapted balance method

The biogenic fraction of a simple solid recovered fuel (SRF) mixture (80 wt% printer paper/20 wt% high density polyethylene) is analyzed with the in-house developed adapted balance method (aBM). This fairly new approach is a combination of combustion elemental analysis (CHNS) and a data reconciliation algorithm based on successive linearisation for evaluation of the analysis results. This method shows a great potential as an alternative way to determine the biomass content in SRF. However, the employed analytical technique (CHNS elemental analysis) restricts the probed sample mass to low amounts in the range of a few hundred milligrams. This requires sample comminution to small grain sizes (<200 μm) to generate representative SRF specimen. This is not easily accomplished for certain material mixtures (e.g. SRF with rubber content) by conventional means of sample size reduction.This paper presents a proof of principle investigation of the sample preparation and analysis of an SRF model mixture with the use of cryogenic impact milling (final sample comminution) and the adapted balance method (determination of biomass content). The so derived sample preparation methodology (cutting mills and cryogenic impact milling) shows a better performance in accuracy and precision for the determination of the biomass content than one solely based on cutting mills. The results for the determination of the biogenic fraction are within 1–5% of the data obtained by the reference methods, selective dissolution method (SDM) and ¹⁴C-method (¹⁴C-M).