State-dependent models of ECS-induced amnesia in rats.

Conducted 3 experiments with a total of 220 male albino Sprague-Dawley rats, to investigate 2 state-dependent hypotheses which state that ECS-induced amnesia occurs when (a) the physiological state during testing is dissimilar from that during training (regardless of when consolidation occurs), or (b) the state at testing differs from that during consolidation (consolidation is assumed to occur after ECS). Data were gathered in a 1-trial passive-avoidance apparatus, and amnesia as a function of states during acquisition, consolidation, and testing was examined. Exp. I failed to support the train-test, state-dependent position. Exp. II produced data consistent with the consolidate-test, state-dependent position, but Exp. III found that the consolidate-test, state-dependent data were confounded by an induced recovery effect independent of S's physiological state at the time of testing. Although inconsistent with either of the state-dependent hypotheses, data support a retrieval-failure view of experimental amnesia. (24 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bayesian Confidence Limits for the Reliability of Cascade Exponential Subsystems

The problem treated here is that of deriving exact Bayesian confidence intervals for the reliability of a cascade system consisting of N independent subsystems each having an exponential distribution of life with a failure rate which is estimated from life test data. The posterior probability density function of the system reliability is derived in closed form, using the method of the Mellin integral transform. The posterior distribution function is obtained, yielding Bayesian confidence limits on the total system reliability. These results, which are believed to be new for N > 3, have an immediate application to problems of reliability evaluation and test planning.     

Bildung von Lanthionin in Nahrungsproteinen

Zusammenfassung In den Nahrungsproteinen liegt der Schwefel in verschiedenen Bindungsformen vor. Den Hauptanteil bildet der in Aminosäuren enthaltene Sulfhydryl-(Cystein-), Disulfid-(Cystin-) und Thioätherschwefel (Methionin-). Als weitere thioätherschwefelhaltige Verbindung konnte von uns die Aminosäure Lanthionin in Weizenkleber- und Eildarproteinen, jedoch erst nach deren Behandlung mit Lauge bzw. deren Erhitzung und nach lebensmittel-technologischer Verarbeitung, festgestellt werden.

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Formation of lanthionine in food proteins

Summary Food proteins contain sulfur in various bonds, consisting in the main part of sulfhydryl (cysteine), disulfide (cystine) and thio-ether sulfur (methionine) contained in amino acids. We have been able to find another compound containing thio-ether sulfur, i.e. lanthionine, an amino acid contained in the proteins of wheat gluten and egg-whites, but only after treatment with alkaline solution and/or subjecting them to heat treatment and food processing.

     

A Bayes Analysis of Availability for a System Consisting of Several Independent Subsystems

A Bayes analysis of system availability A is carried out on the basis of snapshot data obtained on each of the N component subsystems. Application of Bayes formula, using a natural conjugate prior probability density function (pdf), yields the posterior pdf of subsystem availability. Determination of the posterior pdf of system availability requires the derivation of the pdf of the product of N independent random variables, which is accomplished through the use of the Mellin integral transform. From the knowledge of the posterior pdf of A, confidence limits on system availability can be obtained.     

Field testing of arsenic in groundwater samples of Bangladesh using a test kit based on lyophilized bioreporter bacteria

A test kit based on living, lyophilized bacterial bioreporters emitting bioluminescence as a response to arsenite and arsenate was applied during a field campaign in six villages across Bangladesh. Bioreporter field measurements of arsenic in groundwater from tube wells were in satisfying agreement with the results of spectroscopic analyses of the same samples conducted in the lab. The practicability of the bioreporter test in terms of logistics and material requirements, suitability for high sample throughput, and waste disposal was much better than that of two commercial chemical test kits that were included as references. The campaigns furthermore demonstrated large local heterogeneity of arsenic in groundwater, underscoring the use of well switching as an effective remedy to avoid high arsenic exposure.     

Magnetic resonance imaging of solid dental restoration materials using 3D UTE sequences: visualization and relaxometry of various compounds

Object

Due to an increasing scientific interest in MR-imaging of carious lesions and teeth, an accurate signal characterization of dental restoration materials is necessary for optimization of MR sequence protocols and evaluation of material degradation. Therefore, signal yield and relaxation behavior of common dental restoration materials in comparison to those of dentine of extracted human teeth were assessed in vitro by ultrashort echo time (UTE) sequences.

Materials and methods

Eighteen material samples and dentine of two freshly extracted human teeth were investigated on a 3T whole-body clinical MR-scanner. Transverse (T2*) and longitudinal relaxation times (T1) were quantified using a recently published modified Ernst equation that takes relevant in-pulse relaxation effects into account.

Results

All investigated samples could be successfully visualized but maximum signal yield was highly variable between samples. T1-values of the investigated dental restoration materials ranged between 28 and 365 ms, whereas T2*-values ranged between 96 and 917 μs. In contrast, T1-values of dentine (T1 = 545 ms ± 299 ms) were higher, while T2*-values (T2* = 478 μs ± 271 μs) showed similar values.

Conclusions

Dental restoration materials and dentine of extracted human teeth can be visualized by UTE sequences and show a broad range of signal yield and relaxation times.     

Lüftungs- und Klimatechnikgesch?ft verkauft

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Lüftungs- und Klimatechnikgesch?ft verkauft     

Crystallization and melting behaviour of plasticized poly(vinylidenechloride)

Summary The kinetic of the crystallization process of slightly plasticized poly(vinylidenechloride) at room temperature (296 K) can be observed by FTIR spectroscopy. In dependence on the amount of plasticizer the half-time for crystallization decreases due to an increased segmental mobility of the stiff PVDC chains.