The gregarisation pheromone of locusts

Swarming locusts show three physical criteria, i.e. the phase changes of melanisation of the nymphal stages or hoppers, of the proportions of certain body parts (morphometric ratios), and increased genetic recombination (meiotic chiasma frequencies) in the adult. The control of these changes, initiated by aggregation into swarms, i.e. gregarisation, seems to be vested in a pheromone which is produced by all hoppers in both the solitaria and gregaria phases, also by hoppers of the albino strain. Such a pheromone can be extracted from the locust room air and from the locust, these extracts showing high activity in bioassays, primarily in increased chiasma frequencies but also in hopper colour. The extract in risella oil is more efficient than that in petroleum ether and can be distilled to yield an active distillate. The pheromone is secreted in the faeces of hoppers but not of adults. There is evidence in faeces bioassays that all three physical criteria are affected; the pheromone may be called locustone. It is manufactured or secreted in a specific section of the alimentary canal, i.e. the crop. Reception is not through the antennae but through the stigmata. Preliminary chemical analysis of a risella oil air extract distilled into various other solvents showed the presence of a relatively simple saturated aliphatic chain with a carbonyl function, perhaps a ketone or an ester.     

Die Küstenfischerei in der Unter- und Außenweser und die Abwasserbedrohung

Zusammenfassung 1. Weder in der Wesermündung noch vor dieser in der Deutschen Bucht kann erwartet werden, daß eingeleitete Abwässer immer eine schnelle und gute Durchmischung oder sogar eine totale Durchmischung erfahren. Es bilden sich sehr häufig Wasserschlieren, Wasserfahnen, Wasserblasen, Wasserkörper oder Wasserinseln, die sich — entgegen allen Theorien und Berechnungen — der totalen Durchmischung entziehen.2. Die schädlichen Stoffe können mangelhaft oder undurchmischt zusammenbleiben und in mehr oder weniger großen Gebieten biologische Schäden verursachen.3. Ein Schaden in der biologischen Kette kann weiterwirken auf die Nahrungstiere der Garnelen und Fische und damit mittelbar auf diese selbst oder auf deren Ei- und Jugendstadien, auf den Glasaalaufstieg oder auf Muschelkulturen (Korringa 1967).4. Es wäre wünschenswert, die Küstengewässer vor großen Abwassereinleitungen zu schützen. Wenn Großsiedlungen und Industrien darauf angewiesen sind, so muß jedenfalls gefordert werden, daß die Technik alle Möglichkeiten ausschöpft, um die Abwässer soweit unschädlich zu machen, wie es technisch heute möglich ist. Es muß erwartet werden, daß Wirtschaftlichkeitsberechnungen nicht nur die Rentabilität der Industrie, sondern auch die Fischerei (Abb. 3) und die Bedeutung der Küste als Erholungsgebiet einbeziehen (Caspers 1967).5. Die Fischerei erhebt die über 60 Jahre alten Forderungen für die Binnengewässer (Wundsch 1926) heute für die Küstengewässer und das Meer: (a) Das Gewässer darf durch die Abwassereinleitungen nicht so verändert werden, daß die Fischwelt gehindert wird zu leben und sich fortzupflanzen. (b) Die natürliche Fauna und Flora darf nicht vermindert oder in ihrer Zusammensetzung zum Nachteil der Nahrungskette verändert werden. (c) Die technische Durchführbarkeit der Fischerei darf nicht gestört oder unmöglich gemacht werden.

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The inshore-fishery in the lower and outer Weser and the danger of water pollution

In earlier times the fishery of the lower and outer Weser was of a high commercial value. Todays fishery suffers from the development of the Weser River into a great shipping way and increasing water pollution. Many professional fishermen have been replaced by hobby fishermen; these fish in great numbers and, therefore, secure relatively great quantities of fish. In 1966 the value of the total catch of professional and hobby fishermen amounted to about 3 million DM. Such high yields can, however, hardly be expected in the future. Already now the Weser belongs to the-to-mesosaprob zone. The greatest danger is to be seen in the trend of the various industries to settle near the coast and to dump their wastes into rivers and littoral areas expecting fast and complete mixing of the waters. However, the Weser estuary is always stratified horizontally and vertically, hence total mixing wastes never occurs. In view of the great amounts of industrial wastes to be discharged and the hydrographic stratification, severe biological consequences are to be expected. Some of the potential water pollution damages are discussed.

     

CLPP coordinates mitoribosomal assembly through the regulation of ERAL1 levels

Despite being one of the most studied proteases in bacteria, very little is known about the role of ClpXP in mitochondria. We now present evidence that mammalian CLPP has an essential role in determining the rate of mitochondrial protein synthesis by regulating the level of mitoribosome assembly. Through a proteomic approach and the use of a catalytically inactive CLPP, we produced the first comprehensive list of possible mammalian ClpXP substrates involved in the regulation of mitochondrial translation, oxidative phosphorylation, and a number of metabolic pathways. We further show that the defect in mitoribosomal assembly is a consequence of the accumulation of ERAL1, a putative 12S rRNA chaperone, and novel ClpXP substrate. The presented data suggest that the timely removal of ERAL1 from the small ribosomal subunit is essential for the efficient maturation of the mitoribosome and a normal rate of mitochondrial translation.     

Crystal structure of the alpha1beta1 integrin I-domain: insights into integrin I-domain function.

The alpha1beta1 integrin is a major cell surface receptor for collagen. Ligand binding is mediated, in part, through a 200 amino acid inserted 'I'-domain contained in the extracellular part of the integrin alpha chain. Integrin I-domains contain a divalent cation binding (MIDAS) site and require cations to interact with integrin ligands. We have determined the crystal structure of recombinant I-domain from the rat alpha1beta1 integrin at 2.2 A resolution in the absence of divalent cations. The alpha1 I-domain adopts the dinucleotide binding fold that is characteristic of all I-domain structures that have been solved to date and has a structure very similar to that of the closely related alpha2beta1 I-domain which also mediates collagen binding. A unique feature of the alpha1 I-domain crystal structure is that the MIDAS site is occupied by an arginine side chain from another I-domain molecule in the crystal, in place of a metal ion. This interaction supports a proposed model for ligand-induced displacement of metal ions. Circular dichroism spectra determined in the presence of Ca2+, Mg2+ and Mn2+ indicate that no changes in the structure of the I-domain occur upon metal ion binding in solution. Metal ion binding induces small changes in UV absorption spectra, indicating a change in the polarity of the MIDAS site environment.     

Anthranilimide based glycogen phosphorylase inhibitors for the treatment of type 2 diabetes. Part 3: X-ray crystallographic characterization,core and urea optimization and in vivo efficacy

Key binding interactions of the anthranilimide based glycogen phosphorylase a (GPa) inhibitor 2 from X-ray crystallography studies are described. This series of compounds bind to the AMP site of GP. Using the binding information the core and the phenyl urea moieties were optimized. This work culminated in the identification of compounds with single nanomolar potency as well as in vivo efficacy in a diabetic model.     

Multi-body simulation of a canine hind limb: model development, experimental validation and calculation of ground reaction forces

Background  

Among other causes the long-term result of hip prostheses in dogs is determined by aseptic loosening. A prevention of prosthesis complications can be achieved by an optimization of the tribological system which finally results in improved implant duration. In this context a computerized model for the calculation of hip joint loadings during different motions would be of benefit. In a first step in the development of such an inverse dynamic multi-body simulation (MBS-) model we here present the setup of a canine hind limb model applicable for the calculation of ground reaction forces.