Enhanced sorption of PAHs in natural-fire-impacted sediments from Oriole Lake, California

Surface sediment cores from Oriole Lake (CA) were analyzed for organic carbon (OC), black carbon (BC), and their δ(13)C isotope ratios. Sediments displayed high OC (20-25%) and increasing BC concentrations from ～0.40% (in 1800 C.E.) to ～0.60% dry weight (in 2000 C.E.). Petrographic analysis confirmed the presence of fire-derived carbonaceous particles/BC at ～2% of total OC. Natural fires were the most likely cause of both elevated polycyclic aromatic hydrocarbon (PAH) concentrations and enhanced sorption in Oriole Lake sediments prior to 1850, consistent with their tree-ring-based fire history. In contrast to other PAHs, retene and perylene displayed decreasing concentrations during periods with natural fires, questioning their use as fire tracers. The occurrence of natural fires, however, did not result in elevated concentrations of black carbon or chars in the sediments. Only the 1912-2007 sediment layer contained anthropogenic particles, such as soot BC. In this layer, combining OC absorption with adsorption to soot BC (using a Freundlich coefficient n = 0.7) explained the observed sorption well. In the older layers, n needed to be 0.3 and 0.5 to explain the enhanced sorption to the sediments, indicating the importance of natural chars/inertinites in sorbing PAHs. For phenanthrene, values of n differed significantly between sorption to natural chars (0.1-0.4) and sorption to anthropogenic black carbon (>0.5), suggesting it could serve as an in situ probe of sorbents.     

Studies on the formation of lysinomethylalanine and histidinomethylalanine in milk products

From reaction mixtures consisting ofN-acetyldehydroaminobutyric acid methyl ester andN -acetyl-l-lysine orN -acetyl-l-histidine, respectively, distinct amounts of the cross-link amino acidsN -(2-amino-2-carboxy-l-methylethyl)-l-lysine (lysinomethylalanine, LMeAL) andN -(2-amino-2-carboxy-1-methyl-ethyl)-l-histidine (histidinomethylalanine, HMeAL) were isolated via preparative ion-exchange chromatography and identified by¹H- and¹³C-nuclear magnetic resonance. In the amino acid chromatogram, both compounds eluted clearly separated from other basic amino acids. However, neither LMeAL nor HMeAL could be detected in numerous acid hydrolysates of a range of milk products. In model studies, threonine showed a significantly lower tendency for an alkali-induced -elimination reaction compared to serine. The reactivity of the resulting dehydroaminobutyric acid towards nucleophiles was more than tenfold lower as compared to dehydroalanine. Thus, the formation of LMeAL as well as of HMeAL during food processing is negligible.

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Studien zur Bildung von Lysinomethylalanin und Histidinomethylalanin in Milchprodukten

Zusammenfassung Aus Reaktionsansätzen bestehend ausN-Acetyldehydroaminobuttersäurenthylester undN -Acetyl-l-lysin beziehungsweiseN -Acetyl-l-histidin konnten die Crosslink-AminosäurenN -(2-Amino-2-carboxy-1-methyl-ethyl)-l-lysin (Lysinomethylalanin, LMeAL) undN -(2 amino-2-carboxy-2 -methyl-ethyl)-l-histidin (Histidinomethylalanin, HMeAL) durch präparative Ionenaustauschchromatographie isoliert und anschließend durch 1H-und¹³C-NMR identifiziert werden. Das Aminosäurechromatogramm zeigte eine eindeutige Trennung beider Aminosäurederivate von anderen basischen Aminosäuren. Dennoch konnten in einer großen Zahl von Säurehydrolysaten der verschiedensten Milchprodukte weder LMeAL noch HMeAL nachgewiesen werden. In Modelluntersuchungen erfolgte die -Elimination an Threonin im Vergleich zu Serin in einem deutlich geringeren Maße. Die Reaktivität der dabei entstehenden Dehydroaminobuttersäure gegenüber Nucleophilen war mehr als zehnfach geringer als die von Dehydroalanin. Damit kann die Bildung sowohl von LMeAL als auch von HMeAL bei der Verarbeitung von Nahrungsmitteln als vernachlässigbar gering eingeschätzt werden.

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Dedicated to Prof. Dr. W. Baltes on the occasion of his 65th birthday     

Prospects for the use of high-Tc superconductors in fusion magnets and options for their test in SULTAN

In the last few years, the critical current densities of long commercially available REBa₂Cu₃O_7?x (RE-123, where RE represents Y or a rare earth element) coated conductors have reached values of 250 A/cm-width at 77 K and zero applied field. Even higher values of 600 A/cm-w (77 K, B = 0) have been demonstrated in shorter lengths. The attractive features of the use of these high-T_c superconductors (HTS) are operation temperatures above 20 K and/or magnetic fields higher than those envisaged for the ITER TF coils. Possible operation conditions for HTS fusion magnets have been studied taking into consideration the possible further improvements of RE-123 coated conductors. Investigations of stability and quench behavior indicate that stability is not a problem, whereas quench detection and protection need attention. Because of the high currents necessary for fusion magnets, many tapes need to be assembled into a transposed conductor. The qualification of HTS conductors for fusion magnets would require their test at magnetic fields of 11 T and currents well above 10 kA. The possibilities to test straight HTS conductor samples in SULTAN have been considered. For a test at 4.5 K, only the development of a low resistance joint between the HTS conductor under test and the NbTi transformer of SULTAN would be necessary. Tests up to 20 K would require that the HTS sample is connected with the NbTi transformer by a conduction-cooled HTS bus bar of large thermal resistance similar to the HTS module of a current lead. HTS conductor tests at temperatures around 50 K would be possible with modified cryogenics.     

A novel beam-splitting microscope tube for taking stereo-pairs with full resolution Nomarski or phase contrast technique,or with epifluorescence

A device is presented which for the first time allows stereo-pairs to be taken with full resolving power on a single frame, since both single views are formed by the complete diffraction image. The device can be introduced into the mononuclear tube of any light microscope.     

Innovative approaches in integrated assessment modelling of European air pollution control strategies – Implications of dealing with multi-pollutant multi-effect problems

In this paper, crucial aspects of the implications and the complexity of interconnected multi-pollutant multi-effect assessments of both air pollution control strategies and the closely related reduction of greenhouse gas emissions will be discussed. The main aims of the work described here are to identify the core problems which occur when trying to apply current state-of-the-art methodology to conduct integrated assessments – in this context, cost-benefit assessment (CBA) as well as cost-effectiveness assessment (CEA) – using sophisticated computer models and propose solutions to the problems identified. The approaches described will display the integrated use of databases, efficient algorithms and already existing software tools and models in a unified model framework. The first part of the paper discusses the need for new developments in one particular field of Integrated Assessment Models (IAMs), which is the use of (typically) country-specific single pollutant abatement cost curves, which have been applied in a large number of modelling approaches with the aim to find cost-effective solutions for given air quality targets. However, research conducted to find such cost-effective solutions for the non-linear problem of tropospheric ozone abatement (dealing with two primary pollutants and their rather complex relationship to form tropospheric ozone, [see] [Friedrich, R., Reis, S. (Eds.), 2000. Tropospheric Ozone Abatement – Developing Efficient Strategies for the Reduction of Ozone Precursor Emissions in Europe. Springer Publishers] identified basic problems of cost curve based approaches even in this two-pollutant case. The approach discussed here promises to solve the key problems identified, making extensive use of databases in order to provide fast and high quality model input for CEA and CBA. In addition to that, the application of Genetic Algorithms will be discussed as a means to address extremely complex, vast solution spaces which are typical for the tasks IAMs are set to solve nowadays. As the application of the model in extensive assessment studies is currently under way, it is yet too early for a full evaluation of lessons learned. However, initial tests of performance and behaviour have shown robust and promising results.     

James and the physical basis of emotion: A comment on Ellsworth.

It is argued that P. Ellsworth's (1994) interpretation of William James's theory of emotions is not supported by his writings. On the basis of textual evidence and systematic considerations, the authors try to show that, in line with the traditional view, James's theory holds that emotions are identical with feelings of bodily changes, of which autonomic changes are by far the most important ones (i.e., the only ones necessary and sufficient for emotions). Furthermore, the authors argue that James's question of the temporal priority of emotions versus bodily feelings makes good sense even if one acknowledges that these events usually show temporal overlap. (PsycINFO Database Record (c) 2010 APA, all rights reserved)