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Isolated posterior gills of shore crabs,Carcinus maenas, previously acclimated for at least 1 month to brackish water of 10 ‰ S, were connected with an artificial hemolymph circulation by means of thin polyethylene tubings. Gills were symmetrically perfused and bathed with 50 % sea water. Transepithelial potential differences (PDs) and fluxes of sodium between medium and blood were measured under control conditions and following reductions of PDs by means of 5 mM internal (blood side) ouabain, 0.5 mM internal and external (bathing medium) NaCN or by exhaustion of energy reserves along with a prolonged perfusion period of more than 9 h. In these experiments22Na was used as tracer. Each of the three modes of reducing transepithelial potential differences resulted in a decrease in sodium influxes from 500–1000 µmoles g−1 h−1 to 250–400 µmoles g−1 h−1. The findings suggest that sodium influx, which normally greatly exceeds efflux, was diminished by its active component. The remaining non-inhibitable influx equals efflux values. Our findings thus indicate that efflux is completely passive, while influx has — beside a passive component of efflux magnitudes — an additional active portion which is much larger than the passive component. Since ouabain is a specific inhibitor of the Na-K-ATPase, our results confirm previous findings (Siebers et al., 1985) that the basolaterally located Na-K-ATPase generates the transepithelial potential difference in the gills, which is inside negative by about 6–12 mV. Inhibition of the active portion of sodium influx by internal ouabain along with reduced PDs suggests that transepithelial PDs generated by the branchial sodium pump are the driving force for active sodium uptake in hyperregulating brackish water crabs.

A continuous process for the electrosynthesis of sulphones by cathodic reduction of sulphur dioxide in the presence of organic halides has been investigated. The organic halide, consumed in the cathode process, is regenerated at the anode side and the halogen is hence recycled. As a model process, the synthesis of dipropyl sulphone via propyl bromide has been investigated; SO2 and propyl alcohol are the starting materials. The alcohol, simultaneously serving as the anolyte solvent, reduces bromine to give hydrobromic acid which, in turn, regenerates the organic halide by reaction with further alcohol. The cathodic and anodic yields are both promising.

Blackcurrant seed oil is known to be one of the richest natural sources of γ-linolenic (allcis-6,9,12-octadecatrienoic) acid, with values of up to 20% of this acid. These concentrations are sufficient for most applications of the oil, but some utilizations require higher concentrations of γ-linolenic acid. Blackcurrant seed oil also contains up to 14%α-linolenic (allcis-9,12,15-octadecatrienoic) acid. Different fractionation techniques have been evaluated to separate γ-linolenic acid specifically from the other fatty acids present in the oil and, in particular, fromα-linolenic acid.

In a previous report we have shown that microtubule-associated protein tau can be induced to form paracrystals (Lichtenberg, B., E.-M. Mandelkow, T. Hagestedt, and E. Mandelkow. 1988. Nature [Lond.]. 334:359-362). A striking feature was the high degree of elasticity of the molecules. We now report that this property is related to the state of phosphorylation. When tau is dephosphorylated by alkaline phosphatase, it becomes shorter and more elastic; when it is phosphorylated by Ca++/calmodulin-dependent kinase, it becomes longer and stiffer. This may provide a model for the control of structural properties of tau-like molecules by phosphorylation.

Numerical calculation based on the finite element method seems to have become widely accepted as a helpful tool within the design and development departments of the automotive industry. The reason for this is twofold: on the one hand user experience is growing, on the other hand the software capabilities for preprocessing, calculation and postprocessing have reached a certain state of convenience, allowing interactive handling and graphic presentation of results. The requirements of light–weight design while maintaining structural stability, and the use of alternative materials (e.g. plastics, aluminium, etc.) for future car development, will lead to further applications of the finite element method (FEM). In this paper a short overview on today's software capabilities as well as some examples of FEM calculations are presented. The numerical results and the conclusions for the designer are discussed.

Summary A group of 30 alcoholics as identified using the MALT score were examined both within the first 36 h of alcohol withdrawal and then again at the end of a 10-day treatment in hospital. We looked for clinical signs of dehydration, water and electrolyte imbalance, and concentration of steroid metabolites in the urine. Cranial computed tomography was also performed twice, again at the beginning and end of the 10-day period. The size of cerebrospinal fluid spaces was calculated through measuring the frontal interhemisphere distance, the width of cortical sulci, the ventricle III diameter, the Cella media index and also the number of vermal sulci. All patients had a brain atrophy which did not disappear within the 10 days. The neuroradiological parameters remained completely unchanged in the control examination. However, the laboratory parameters of the internal milieu had normalized. Therefore, it is submitted that the shrinkage of the brain of alcoholics cannot be due to a reversible intra- or extracellulary dehydration. There was also no proof of a hormonal cause for the brain shrinkage. As a consequence other etiological factors gain importance, such as malnutrition or a toxic alcohol effect.

Zusammenfassung: Aus kranken Engerlingen vonMelolontha melolontha L. wurden zwei pathogene Bakterienstämme, die als Stamm A1 und 175 bezeichnet werden, und ein Pilzstamm (aus derBeauveria-Gruppe) isoliert. Diese drei Stämme erwiesen sich in zahlreichen im Laboratorium durchgeführten Infektionsversuchen recht wirksam. Die Wirkung des Stammes A1 und des Pilzes wurde 1954 in sechs bezw. fünf Feldversuchen untersucht. Im Jahre 1955 wurde wiederum der Stamm A1 und neu der Stamm 175 in zehn Freilandversuchen geprüft. Diese beiden Stämme wurden im Felde einzeln und kombiniert geimpft. Die Herstellung des Impfmateriales, die Stärke der Impfung (Tab. 1 und 2), die Durchführung und Auswertung der Versuche werden geschildert. Die Feldversuche 1954 wurden im Juli bis anfangs August angelegt. In der ersten Erfolgskontrolle, die im Herbst 1954 durchgeführt wurde, bewegte sich die Wirksamkeit des Stammes A1 in fünf Versuchen zwischen 31,8 und 51,7%. Der sechste Versuch fiel negativ aus. Die Wirksamkeit des Pilzes betrug nur in einem einzigen Versuch 56,1%, in den vier anderen überstieg er nicht 20%. Die zweite Kontrolle wurde im Frühjahr 1955 unternommen. In vier Versuchen, mit Stamm A1, schwankte die Wirksamkeit zwischen 37,5 und 66,9%. In den zwei anderen Versuchen war die Mortalität in den Kontrollparzellen grösser als in den behandelten. In drei Versuchen ergab die Impfung mit dem Pilz eine Wirksamkeit von 23,9–64,7% (Tab. 4). Die Feldversuche 1955 wurden in der Zeit zwischen Mai und anfangs August angelegt. Fünf von den insgesamt zehn Versuchen wurden zweimal kontrolliert. Bei der ersten Kontrolle konnte einzig in zwei Versuchen eine Wirksamkeit von 28,8–39,4% nach Impfung mit Stamm A1 und 175, sowie nach kombinierter Impfung der beiden festgestellt werden. In der zweiten Erfolgskontrolle, die im Herbst 1955 zur Durchführung gelangte, fiel das Ergebnis in zwei Versuchen negativ aus. Im Durchschnitt der anderen acht Versuche betrug die Wirksamkeit rund 46% für jede Behandlungsart. In zwei Versuchen, in welchen sich die Behandlung gegen frisch schlüpfende L1-Stadien des Engerlings richtete, betrug die Wirksamkeit nach kombinierter Impfung mit A1 und 175 durchschnittlich 56,3% (Tab. 5).

1. Trypsin digestion of Micrococcus lysodeikticus polynucleotide phosphorylase (nucleoside diphosphate–polynucleotide nucleotidyltransferase) causes a progressive increase in electrophoretic mobility in polyacrylamide gels of the single active degradation product. 2. A marked increase in primer requirement for CDP polymerization occurs before a more mobile product is formed. 3. α-Chymotrypsin digestion yields a product that separates into several active species on polyacrylamide-gel electrophoretograms. 4. No separation of ADP-and CDP-polymerization activities occurs during electrophoresis after either trypsin or α-chymotrypsin treatment.

Sowohl für die Darstellung der enterochromaffinen Zellen als auch des Zinks in der Darmschleimhaut mit dem Silbersulfidverfahren spielen Fixierungswirkungen eine entscheidende Rolle.

We investigated the spectral behavior of a white-light continuum generated in air by 2-TW femtosecond laser pulses at 800 nm. The spectrum extends at least from 300 nm to 4.5 μm. From 1 to 1.6 μm the continuum's intensity increases strongly with the laser energy and depends on the initial chirp.