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Plant U-box armadillo repeat (PUB-ARM) ubiquitin (Ub) ligases have important functions in plant defense through the ubiquitination of target proteins. Defense against pathogens involves vesicle trafficking and the formation of extracellular vesicles. The PUB-ARM protein SENESCENCE ASSOCIATED UBIQUITIN E3 LIGASE1 (SAUL1) can form patches at the plasma membrane related to tethering multi-vesicular bodies (MVBs) to the plasma membrane. We uncovered the structure of a full-length plant ubiquitin ligase and the structural requirements of SAUL1, which are crucial for its function in patch formation. We resolved the structure of SAUL1 monomers by small-angle X-ray scattering (SAXS). The SAUL1 model showed that SAUL1 consists of two domains: a domain containing the N-terminal U-box and armadillo (ARM) repeats and the C-terminal ARM repeat domain, which includes a positively charged groove. We showed that all C-terminal ARM repeats are essential for patch formation and that this function requires arginine residue at position 736. By applying SAXS to polydisperse SAUL1 systems, the oligomerization of SAUL1 is detectable, with SAUL1 tetramers being the most prominent oligomers at higher concentrations. The oligomerization domain consists of the N-terminal U-box and some N-terminal ARM repeats. Deleting the U-box resulted in the promotion of the SAUL1 tethering function. Our findings indicate that structural changes in SAUL1 may be fundamental to its function in forming patches at the plasma membrane.

Three institutes of the Universities of Applied Sciences that are active in Chemistry and Life Sciences present a selection of their activities in the field of environmental sciences. These projects include analytical monitoring, removal of micropollutants, waste reduction and valorization.

Time and size resolved data of trace elements were obtained from measurements with a rotating drum impactor (RDI) and subsequent X-ray fluorescence spectrometry. Trace elements can act as indicators for the identification of sources of particulate matter 10) in ambient air. Receptor modeling was performed with positive matrix factorization (PMF) for trace element data from an urban background site in Zürich, Switzerland. Eight different sources were identified for the three examined size ranges (PM1−0.1, PM2.5−1 and PM10−2.5): secondary sulfate, wood combustion, fire works, road traffic, mineral dust, de-icing salt, industrial and local anthropogenic activities. The major component was secondary sulfate for the smallest size range; the road traffic factor was found in all three size ranges. This trace element analysis is complemented with data from an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (AMS), assessing the PM1 fraction of organic aerosols. A separate PMF analysis revealed three factors related to three of the sources found with the RDI: oxygenated organic aerosol (OOA, related to inorganic secondary sulfate), hydrocarbon-like organic aerosol (HOA, related to road traffic) and biomass burning organic aerosol (BBOA), explaining 60 %, 22 % and 17 % of total measured organics, respectively. Since different compounds are used for the source classification, a higher percentage of the ambient PM10 mass concentration can be apportioned to sources by the combination of both methods.

The corrosion behavior of shotcrete in the safety gallery of the motorway tunnel Gotthard was investigated. The tunnel was built in 1972/73, sections with waterleading rocks show various signs of concrete degradation. Samples of corroded concrete were investigated in the laboratory for their chemical and mineralogical compositions. X-ray diffraction (XRD), X-ray fluorescence (XRF), and methods to determine acid-soluble silicon compounds and insoluble contents were used to characterize the samples.Comparisons of original concrete with corroded samples show the existence of discrete interaction mechanisms. These mechanisms lead either to harmless efflorescence, to detachments of concrete from the rock or to more or less complete degradation of the cement paste. Delamination or deterioration of concrete are related to the amount and kind of transformation products formed due to action of specific ionic species of the interacting water. Special attention is drawn to the formation of thaumasite, which may be formed under special conditions, even when sulfate-resistant cements have been used.Physical and chemical properties of the cement paste as well as the composition of interacting water are important for the service life of a concrete structure. The potential of concrete degradation due to interaction with aggressive water may be lowered by preventing its contact or by draining the water not to force it to penetrate the concrete structure.

Some applications of Analytical Electron Microscopies (AEM) for the characterization of colloids in natural waters are presented. These techniques go much beyond the basic level of morphological observation and render possible to gain detailed physico-chemical information difficult to obtain by conventional analytical methods. Hence, AEM appear as a challenging necessity for understanding the colloid-mediated transport of toxics in the environment.

Some applications of Analytical Electron Microscopies (AEM) for the characterization of colloids in natural waters are presented. These techniques go much beyond the basic level of morphological observation and render possible to gain detailed physico-chemical information difficult to obtain by conventional analytical methods. Hence, AEM appear as a challenging necessity for understanding the colloid-mediated transport of toxics in the environment.

Modern analytical chemistry relies on a multiplicity of different instrumental methods, their ranges of application being partially overlapping, partially supplementary. The universally utilizable dream method, which solves all possible problems does not exist. Nevertheless, every existing instrumental analytical method can be described as a modular composition including three steps: provocation, reaction, and detection. Based on this concept, the irritating multiplicity of existing analytical methods can be well surveyed.

Modern analytical chemistry relies on a multiplicity of different instrumental methods, their ranges of application being partially overlapping, partially supplementary. The universally utilizable dream method, which solves all possible problems does not exist. Nevertheless, every existing instrumental analytical method can be described as a modular composition including three steps: provocation, reaction, and detection. Based on this concept, the irritating multiplicity of existing analytical methods can be well surveyed.