From Neweul to Neweul-M<Superscript>2</Superscript>: symbolical equations of motion for multibody system analysis and synthesis

The state-of-the-art for deriving symbolical equations of motion for multibody systems is reviewed. The fundamentals of formalisms based on Newton–Euler equations are presented and the recent development of a research software called Neweul-M² is highlighted. The modeling approach with commands and a graphical user interface are discussed as well as system analysis options, control design by export to Matlab/Simulink, and parameter optimization for system synthesis. The alternatives within the program using symbolic and numeric approaches are emphasized. A double pendulum is used to explain the program features and a vehicle benchmark model is presented as an example. Advanced applications include closed kinematic loops and flexible bodies.     

Actinic brachial plexus lesion

OBJECTIVES: To prove or disprove this assumption that in neuropathy patients with abundant spontaneous activity, peak-ratio interference pattern analysis may lead to false negative results. METHODS: Spontaneous activity >100 microV, automatically analysed by turn/amplitude analysis and expressed as (turns/second)/2 ((T/S)/2), and interference patterns, analysed by the peak-ratio technique, were recorded, one after the other, from the right anterior tibial muscle of 21 patients with neuropathy, aged 36-87 years. RESULTS: The mean number of spontaneous discharges ((T/S)/2) was 12.3 (range 5.5-26) and its mean amplitude 261 microV (range 146-478 microV). Despite this abundant spontaneous activity, peak-ratio analysis was neurogenic in 81% of the patients. All peak-ratio parameters were independent on the amount and amplitude of spontaneous discharges. CONCLUSIONS: Spontaneous discharges >100 microV could be adequately assessed by means of the turn/amplitude analysis and did not influence peak-ratio analysis in neuropathies.     

Development of a reduction process and test results of the reduction equilibria of wustite as a function of oxygen content and temperature

A new measurement technique allows the continuous measurement of the oxygen contents of the wustite as a function of temperature without having to pass through the disintegration of the wustite to iron and magnetite and have the accompanying problems during the chemical analysis by cooling the sample. Measurements are carried out in form of isothermal oxygen reduction tests, starting with pure Fe₂O₃ in a thermogravimetric balance with an upstream gas mixer which, operating with CO₂/CO gas mixtures, ensures a graduation of the input reduction potential CO'₂ in steps of 1%. Simultaneous weighing of the test material sample permits, by means of the measured weight loss and relation to the charged amount of Fe₂O₃, a very accurate measurement of the oxygen concentration within the test material at any point in time during testing. Testing was carried out along these lines in the range between 700 and 1300°C. The results show that, at constant temperatures, the wustite oxygen contents decrease linearly from the right- to the left-hand boundary of the wustite field, with the oxygen pressure of the gas phase (log p_CO2/p_CO or log pO₂). When comparing these results with the findings of Darken and Gurry, a difference becomes apparent in the curves of the log pO₂ values as a function of the temperature. While our own curves are substantiated by very many measured values, the curves of Darken and Gurry are based on only twenty-three values at four different temperatures. Based on this result, systems of equations are developed which describe the homogeneous field of the wustite in the Fe-O-C reduction system without any gaps. An equivalent system of equations can also be developed from the values of a literature evaluation carried out by Giddings and Gordon. The curves resulting from the two equations do not differ very greatly. But the differences are large enough for corresponding variances to be expected when establishing the wustite boundaries and, thus, the position of the wustite field in the phase diagram.     

Serum amyloid A (SAA) protein enhances formation of cyclooxygenase metabolites of activated human monocytes

The protease inhibitors, ritonavir, indinavir and saquinavir, the most potent anti-HIV drugs developed to date, interact with many drugs by competing for CYP3A4, an enzyme central to the metabolism of a wide variety of compounds. Human liver microsomes were used to compare inhibition by these three protease inhibitors. The inhibition was the greatest with ritonavir and indinavir and less potent with saquinavir.     

Modeling Steady-State Biofilms with Dual-Substrate Limitations

This Technical Note presents a systematic analysis of a steady-state biofilm model for the simultaneous utilization of an electron donor and an electron acceptor. It shows that the flux of the electron donor is balanced by the flux of the electron acceptor and the concentrations of the two substrates linearly depend on each other in a steady-state biofilm. An analytical solution can be derived for the substrate fluxes into the biofilm as direct functions of the bulk substrate concentrations. This analytical solution, not much more complicated than the one given by the classic single-substrate biofilm model, eliminates the need to identify the rate-liming factor from the two substrates prior to using it. Comparing the single-substrate and the dual-substrate biofilm models shows that the difference between the two for predicting the flux of the limiting substrate of a deep biofilm can be significant when the bulk concentration of the nonlimiting substrate becomes comparable with or less than its Monod half-saturation constant.     

Amygdalar unit activity during three learning tasks: Eyeblink classical conditioning, Pavlovian fear conditioning, and signaled avoidance conditioning.

Neural activity in central and basolateral amygdala nuclei (CeA and BLA, respectively) was recorded during delay eyeblink conditioning, Pavlovian fear conditioning, and signaled barpress avoidance. During paired training, the CeA exhibited robust learning-related excitatory activity during all 3 tasks. By contrast, the BLA exhibited minimal activity during eyeblink conditioning, while demonstrating pronounced increases in learning-related excitatory responsiveness during fear conditioning and barpress avoidance. In addition, the relative amount of amygdalar activation observed appeared to be related to the relative intensity of the unconditioned stimulus and somatic requirements of the task. Results suggest the CeA mediates the Pavlovian association between sensory stimuli and the BLA mediates the modulation of instrumental responding through the assignment of motivational value to the unconditioned stimulus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The xenoestrogen bisphenol A induces growth, differentiation, and c-fos gene expression in the female reproductive tract

The xenoestrogen bisphenol A (BPA) has been shown to mimic estrogen both in vivo and in vitro. BPA stimulates PRL secretion and the expression of a PRL regulating factor from the posterior pituitary in the estrogen-sensitive Fischer 344 rat (F344), but not in Sprague-Dawley (SD) rats. The goal of the present studies was to examine the in vivo actions of BPA on the reproductive tract. The specific objectives were 1) to characterize the short term effects of BPA on cell proliferation and c-fos expression in the uterus and vagina, and 2) to compare the effects of prolonged exposure to low doses of BPA on the reproductive tract of F344 and SD rats. Treatment with single high doses of BPA induced cell proliferation in the uterus and vagina of ovariectomized F344 rats, as determined by bromodeoxyuridine immunostaining. This proliferation was dose dependent (from 37.5-150 mg/kg) and followed a time course similar to that of estradiol (E2). Quantitative RT-PCR revealed that both BPA and E2 increased c-fos messenger RNA levels in the uterus 14- to 16-fold within 2 h, which returned to basal levels after 6 h. In the vagina, BPA-induced c-fos expression remained elevated for up to 6 h, compared with the transient increase caused by E2. Treatment of F344 rats for 3 days with continuous release capsules that supplied a much lower dose of BPA (approximately 0.3 mg/kg x day) resulted in hypertrophy, hyperplasia, and mucus secretion in the uterus and hyperplasia and cornification of the vaginal epithelium. The reproductive tract of SD rats did not respond to this treatment paradigm with BPA. These studies demonstrate that 1) the molecular and morphological alterations induced by BPA in the uterus and vagina are nearly identical to those induced by estradiol; 2) the vagina appears to be especially sensitive to the estrogenic actions of BPA; 3) the reproductive tract of the inbred F344 rat appears more sensitive to BPA than that of the outbred SD rat; and 4) continuous exposure to microgram levels of BPA is sufficient for exerting estrogenic actions.     

Microbial Abundance in the Schwertmannite Formed in a Mine Water Treatment Plant

Treatment of acidic iron- and sulfate-rich mine waters in a pilot plant at the opencast lignite mining pit Nochten (Lusatia, Germany) involves microbial iron oxidation and subsequent precipitation of the iron-oxyhydroxysulfate schwertmannite. To determine if recirculation of schwertmannite can stabilize and optimize the oxidation process, cell number, viability, and diversity of the bacterial community in schwertmannite precipitated on carrier material and stored schwertmannite were analyzed. In schwertmannite on carrier material, the total cell number decreased slightly with increasing mineral depth, whereas the percentage of viable cells decreased significantly. The microbial community, investigated by fluorescence-in-situ-hybridization (FISH) and terminal restriction fragment length polymorphism (T-RFLP), revealed the presence of the iron-oxidizing bacterium “Ferrovum” sp. and relatives of Gallionella, independent of mineral depth. Analysis of the viability of microorganism in stored schwertmannite indicated an almost constant percentage of viable cells over 42 days.     

Untersuchungen über die Wirkung des Mangans bei der Entschwefelung im Hochofen

Metallurgische Betrachtungen zum Verhalten des Mangans im Hochofen. Eigene Versuchsreihen zum getrennten Erfassen des Manganverhaltens bei der Reduktion über die Reaktionskennzahlen K_Fe,Si, K_MnO und K_Mn,Si und bei der Entschwefelung über die Schwefelverteilung L_FeS und Reaktionskennzahl K_MnS. Beschreibung der Versuchsanlage und Versuchsdurchführung. Umfang der Versuche und Auswertung der Ergebnisse. Schlußfolgerungen über die Wirkung des Mangans bei der Entschwefelung im Hochofen.