Configurable Resistive Response in BaTiO3 Ferroelectric Memristors via Electron Beam Radiation

Ferroelectric oxide memristors are currently in the highlights of a thriving area of research aiming at the development of nonvolatile, adaptive memories for applications in neuromorphic computing. However, to date a precise control of synapse-like functionalities by adjusting the interplay between ferroelectric polarization and resistive switching processes is still an ongoing challenge. Here, it is shown that by means of controlled electron beam radiation, a prototypical ferroelectric film of BaTiO₃ can be turned into a memristor with multiple configurable resistance states. Ex situ and in situ analyses of current/voltage characteristics upon electron beam exposure confirm the quasi-continuous variation of BaTiO₃ resistance up to two orders of magnitude under the typical experimental conditions employed in electron beam patterning and characterization techniques. These results demonstrate an unprecedented effective route to locally and scalably engineering multilevel ferroelectric memristors via application of moderate electron beam radiation.     

Visual–haptic perception of compliant objects in artificially generated environments

Perception of compliant objects through a human system interface with visual–haptic feedback was investigated. Participants had to explore virtual cubes at different compliances by squeezing them with their fingers and observing them visually and haptically. The cubes were rendered by admittance control. Perception of compliance was analyzed using an adaptive staircase method. Results showed that visual–haptic perception of compliant environments is less accurate than perception of position and force stimuli. Furthermore, due to the important role of the visual feedback cross-modal comparisons are more difficult than bimodal comparisons.

Bestimmung von reduziertem und oxydiertem Glutathion in Weizenmehlen und -teigen

Zusammenfassung Für die quantitative Analyse von reduziertem (GSH) und oxydiertem (GSSG) Glutathion in Cerealien wurde das folgende Verfahren entwickelt: Extraktion eines Mehles oder Teigs und Carboxymethylierung des GSH, Gelfiltration an Sephadex G-50, Chromatographic an Dowex 50 WX8 und nach alkalischer Spaltung Bestimmung des abgetrennten GSSG mit 5,5-Dithio-bis(2-nitrobenzoesaure), Abtrennung des carboxymethylierten GSH an Dowex 1X8 und Bestimmung mit 2,4,6-Trinitrobenzoesulfonsäure. In drei Sorten von Weizenmehlen wurden 0,27–0,46 mol/g GSH and 0,26–0,38 mol/g GSSG gefunden. Beim Kneten (5 min) verschwand das GSH und das GSSG nahm entsprechend zu.

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Determination of reduced and oxidised glutathione in wheat flours and doughs

Summary A quantitative method for the analysis of reduced (GSH) and oxidised (GSSG) glutathione in cereals has been developed. The steps are: Extraction of the flour or dough and carboxymethylation of GSH, gel filtration on Sephadex G-50, chromatography on Dowex 50 WX8 and after basic cleavage determination of the separated GSSG with 5,5-dithio-bis(2-nitrobenzoic acid), separation of carboxymethylated GSH on Dowex 1X8 and determination with 2,4,6-trinitrobenzenesulfonic acid. When analysing for the amount of GSH and GSSG in flours of three varieties of wheat the former ranged from 0.27 to 0.46 mol/g and the latter from 0.26 to 0.38 mol/g. After kneading for 5 min to a dough the GSH disappeared with a corresponding increase in GSSG.

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Herrn Prof. Dr. L. Acker zu seinem 65. Geburtstag gewidmet

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Wir danken der AIF und dem Forschungskreis der Ernährungsindustrie für die finanzielle Unterstützung derArbeit. Frl. Ch. Hopfer danken wir für die geschickte experimentelle Mitarbeit     

Amphiphile und Mesogene Kohlenhydrate. 10. Mesophasenwechsel bie amphiphilen Tetradecyl-(N-acylamino)-2-desoxy-1-thio-β-D-glucopyranosiden durch Acylkettenvariation

Amphiphilic and Mesogenic Carbohydrates. 10. Change of the Type of the Mesophase by Variation of the Acyl Chain of Amphiphilic Tetradecyl (N-acylamino)-2-deoxy-1-thio-β-D -glucopyranosides The homologous amphiphilic tetradecyl-2-(N-alkanoylamino)-2-deoxy-1-thio-β-D -glucopyranosides 5a–f were synthesized from the 2-(N-alkanoylamino)-2-deoxy-D -glucopyranoses 1a–f via the glucosyl chlorides 2a–f , the glucosyl isothiuronium chlorides 3a–f , and the acetylated thioglucosides 4a–f . On heating the amphiphiles 5a–f form different types of liquid crystalline phases in dependence of the length of the acyl chain, i.e. 5a and 5b form smectic phases, 5d–f form columnar mesophases. Polarisation microscopy, DSC-measurements and contact preparations were used to characterise the liquid crystaline phases.     

Farm-gate nutrient balances of grassland-based milk production systems with full- or part-time grazing and fresh herbage indoor feeding at variable concentrate levels

Nutrient Cycling in Agroecosystems - Farm-gate balances for nitrogen (N) and phosphorus (P) were used to determine the potential nutrient surplus and nutrient-use efficiency of three...     

Screening of protease inhibitors as antiplasmodial agents. Part I: Aziridines and epoxides

A broad protease-based and cell-based screening of protease inhibitors yielded the aziridine-2-carboxylic acid derivative 2 a and the N-acylated aziridine-2,3-dicarboxylic acid derivatives 32 a and 34 b as the most potent inhibitors of falcipain-2 and falcipain-3 (IC(50) falcipain-2: 0.079-5.4 microM, falcipain-3: 0.25-39.8 microM). As the compounds also display in vitro activity against the P. falciparum parasite in the submicromolar and low micromolar range, these compound classes are leads for new antiplasmodial falcipain inhibitors.     

Attraction Pheromone of The Benthic Diatom <Emphasis Type="Italic">Seminavis robusta</Emphasis>: Studies on Structure-Activity Relationships

Recently the first pheromone of a marine diatom was identified to be the diketopiperazine (S,S)-diproline. This compound facilitates attraction between mating partners in the benthic diatom Seminavis robusta. Interestingly, sexualized S. robusta cells are attracted to both the natural pheromone (S,S)-diproline as well as to its enantiomer (R,R)-diproline. Usually stereospecificity is a prerequisite for successful substrate-receptor interactions, and especially pheromone perception is often highly enantioselective. Here we introduce a structure-activity relationship study, to learn more about the principles of pheromone reception in diatoms. We analyzed the activity of nine different diketopiperazines in attraction and interference assays. The pheromone diproline itself, as well as a pipecolic acid derived diketopiperazine with two expanded aliphatic ring systems, showed the highest attractivity. Hydroxylatoin of the aliphatic rings abolished any bioactivity. Diketopiperazines derived from acyclic amino acids were not attrative as well. All stereoisomers of both the diproline and the pipecolic acid derived diketopiperazine were purified by enantioselective high-performance liquid chromatography, and application in bioactivity tests confirmed that attraction pheromone perception in this diatom is indeed not stereospecific. However, the lack of activity of diketopiperazines derived from acyclic amino acids suggests a specificity that prevents misguidance to sources of other naturally occurring diketopiperazines.     

Consequences of client-initiated workplace violence: The role of fear and perceived prevention.

The authors suggested and tested a model of the consequences of client-initiated workplace violence, introducing perceived prevention of violence and perceived coping ability as factors that reduce fear of future violence and mitigate negative personal and organizational consequences. Survey data from 330 frontline staff from job centers and social security offices were analyzed using structural equation modeling. The data supported the model and confirmed the central role of the fear of violence with regard to outcomes such as psychological and physical well-being or irritability. Results point further to perceived prevention of violence as an important factor that influences fear levels in different ways, predicts turnover intentions, and should therefore be considered when managers aim to address the consequences of client-initiated violence and threats. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Replacing maize silage plus soybean meal with red clover silage plus wheat in diets for lactating dairy cows

The objectives of this study were to evaluate the effects of replacing maize silage plus soybean meal with red clover silage (RCS) plus wheat on feed intake, diet digestibility, N partitioning, urinary excretion of purine derivatives, and milk production in dairy cows. Forty-four lactating German Holstein cows were used in a 4 × 4 Latin square design with 21-d periods composed of a 13-d adaptation phase followed by an 8-d sampling phase. Experimental diets offered as total mixed ration consisted of a constant forage-to-concentrate ratio (75:25) with targeted proportions of RCS-to-maize silage of 15:60 (RCS₁₅), 30:45 (RCS₃₀), 45:30 (RCS₄₅), and 60:15 (RCS₆₀) on a dry matter (DM) basis. Increasing the proportion of RCS plus wheat in the diet decreased linearly the intake of DM from 22.4 to 19.8 kg/d, and of organic matter from 21.1 to 18.1 kg/d. The apparent total tract digestibility (ATTD) of DM and organic matter did not differ across diets and averaged 68.4 and 70.5%, respectively. However, ATTD of N decreased linearly from 68.5 to 63.2%, whereas ATTD of neutral detergent fiber and acid detergent fiber increased linearly from 50.4 to 59.6% and from 48.4 to 57.7%, respectively, when increasing the proportion of RCS plus wheat. Fecal N excretion increased from 31.6 (RCS₁₅) to 37.2% (RCS₆₀) of N intake, whereas urinary N excretion was the lowest (32.8% of N intake) with RCS₄₅. Hence, N efficiency (milk N/N intake) decreased linearly with incremental levels of RCS plus wheat, being the lowest when feeding RCS₆₀ (25.4%), probably due to increased nonprotein N proportion in total dietary N. Urinary excretion of purine derivatives decreased linearly from 378 to 339 mmol/d, which suggests that increasing levels of RCS plus wheat reduced the microbial crude protein flow at the duodenum. Milk yield and milk protein concentration declined linearly from 35.9 to 30.2 kg/d and from 3.20 to 3.01%, respectively, when increasing the proportion of RCS plus wheat. In conclusion, caution should be taken before introducing high levels of RCS plus wheat in diets of high-yielding dairy cows. However, RCS plus wheat can be included up to 30% of the dairy cow diet (DM basis) without a reduction in lactation performance.