Dietary use of Red Beet Crunchable Tablets of Freeze-Dried Red Beet Pulp

The formulation of crunchable tablets of freeze-dried red beet pulp, a material of therapeutic and dietary value, is described. Various diluants, binders, lubricants, sweeteners and flavoring were chosen to provide desirable organoleptic properties, adequate stability and convenient manufacturing characteristics. 13 different formulations were tested and appraised by a panel for acceptability.     

Novel insights into siderophore formation in myxobacteria

The myxochelins are catecholate-type siderophores produced by a number of myxobacterial strains, and their corresponding biosynthetic gene clusters have been identified in Stigmatella aurantiaca Sg a15, and Sorangium cellulosum So ce56; the latter being presented in this work. Biochemical and genetic studies described here further clarify myxochelin biosynthesis. In addition to the myxochelin A biosynthetic complex, the aminotransferase MxcL is required in order to form myxochelin B, starting from 2,3-dihydroxy benzoic acid and L-lysine. Additionally, the substrate specificity of the myxochelin A biosynthetic complex was analyzed in vitro; this led to the formation of novel myxochelin derivatives. Furthermore, MxcD was over-expressed and its function as an active isochorismic acid synthase in Escherichia coli was verified by complementation studies, as was activity in vitro. The organization of the myxochelin gene cluster of S. cellulosum So ce56 was compared to that of the Sg a15 gene cluster. The comparison revealed that although the organization of the biosynthetic genes is completely different, the biosynthesis is most probably extremely similar.     

Structure and biosynthesis of myxochromides S1-3 in Stigmatella aurantiaca: evidence for an iterative bacterial type I polyketide synthase and for module skipping in nonribosomal peptide biosynthesis

The myxobacterium Stigmatella aurantiaca DW4/3-1 harbours an astonishing variety of secondary metabolic gene clusters, at least two of which were found by gene inactivation experiments to be connected to the biosynthesis of previously unknown metabolites. In this study, we elucidate the structures of myxochromides S1-3, novel cyclic pentapeptide natural products possessing unsaturated polyketide side chains, and identify the corresponding biosynthetic gene locus, made up of six nonribosomal peptide synthetase modules. By analyzing the deduced substrate specificities of the adenylation domains, it is shown that module 4 is most probably skipped during the biosynthetic process. The polyketide synthase MchA harbours only one module and is presumably responsible for the formation of the variable complete polyketide side chains. These data indicate that MchA is responsible for an unusual iterative polyketide chain assembly.     

Varations in maize pollen emission and deposition in relation to microclimate

The coexistence of genetically modified (GM) crops with conventional crops has become a subject of debate and inquiry. Maize (Zea mays L.) is one of the most cultivated crop plants in the world and there is a need to assess the risks of cross-pollination. Concentration and deposition rate downwind from different-sized maize crops were measured during three flowering seasons, together with micrometeorological conditions in the surrounding environment. Pollen release started once the air vapor pressure deficit (VPD) increases above 0.2 to 0.5 kPa. Moreover, the dynamics of release was correlated with the dynamics of VPD surrounding the tassels. Horizontal deposition appeared to follow a power law over short distance downwind from the source, and the dispersal distance increased with the source canopy height and the roughness length of the downwind canopy. This work also provides a data set containing both pollen measurements and contrasting weather conditions to validate dispersal models and further investigate maize pollen dispersal processes.     

On Blends of Polyamide 6 and a Hyperbranched Aramid

The hyperbranched (HB) aromatic polyamide synthesised by direct polycondensation of 5‐(4‐aminobenzoylamino)isophthalic acid (ABZAIA) has been solution‐ and melt‐ blended with polyamide 6 (PA6) incorporating different end groups. The concentration of p(ABZAIA) in PA6 has been varied from 5 to 30 wt.‐% in order to evaluate the influence of hyperbranched polymer content on blend properties. Viscosity and glass transition (T_g) data of the solution blends underlined the full miscibility between the components in the explored composition range. The miscibility was not related to any specific type of PA6 end group, thus suggesting a major role for its amide groups in interacting (presumably via hydrogen bonding) with HB functional end groups. Well‐separated powder particles have been obtained by precipitation from diluted solutions both for the neat polymers and for the blends. Also, in the case of blends prepared by melt mixing T_g linearly increased with the HB polymer content, again confirming full miscibility between the blend components. Blend characterisation, solubility tests and melt rheology supported the idea that p(ABZAIA) forms reactive blends with polyamide 6 by melt mixing. As a consequence of these reactions, the hyperbranched aramid strongly modified the rheological behaviour of PA6.

Formation of well dispersed spherical and homogeneous particles after precipitation of a PA6 dilute solution.     

Memoization-Based Proof Search in LF: An Experimental Evaluation of a Prototype

Elf is a general meta-language for the specification and implementation of logical systems in the style of the logical framework LF. Proof search in this framework is based on the operational semantics of logic programming. In this paper, we discuss experiments with a prototype for memoization-based proof search for Elf programs. We compare the performance of memoization-based proof search, depth-first search and iterative deepening search using two applications: 1) Bi-directional type-checker with subtyping and intersection types 2) Parsing of formulas into higher-order abstract syntax. These experiments indicate that memoization-based proof search is a practical and overall more efficient alternative to depth-first and iterative deepening search.     

Untersuchungen über den Einfluß einer Ultraschall-Wechselbeanspruchung auf das Verformungsverhalten von weichem Eisen

Einfluβ der thermischen Vorgeschichte auf die Ausbildung der Streckgrenze weicher Stähle. Einfluβ einer 20-kHz-Beschallung verschiedener Amplituden bei Temperaturen zwischen 20 und 300°C auf Versetzungsstrukturen und Spannung-Dehnung-Kurven bei Raumtemperatur weicher Stähle verschiedener Herstellungsarten. Einfluβ der Beschallungsfrequenz bei der Ermittlung der Dauerschwingfestigkeit.     

Lake Jabel restoration project: Phosphorus status and possibilities and limitations of diversion of its nutrient-rich main inflow

External and internal phosphorus loading was studied in 1996 in the anthropogenically eutrophicated Lake Jabel, which is located in Mecklenburg (north‐eastern Germany). It has a dimictic 23‐m‐deep northern basin, a 19‐m‐deep middle basin and a 6‐m‐deep polymictic southern basin. The main tributary, Grabowhöfer Grenzgraben, which enters via a leaching field from a waste‐water treatment plant, has been identified as the major nutrient discharge (80% of total phosphorus loading) into the northern basin. The sediment is the second largest source of phosphorus for Lake Jabel, contributing 25.7%, 27.4% and 2.4% of the overall phosphorus load to the northern, middle and southern basins, respectively. Although the favoured diversion of the Grabowhöfer Grenzgraben would contribute to a reduction of 1.22 t P and 20.94 t NO₃^‐–‐N per year, it is mainly rejected for the following reasons. If the extreme monthly nitrate supply, between 4.84 and 189.6 mg N m^‐2 day^–1 ceased, the release of redox‐sensitive phosphorus in the northern basin would increase by a factor of 0.54, which is with 41.1% total phosphorus, twice as high as that in the middle basin. In addition, the nitrate supply can substantially lower the seasonal precipitation of stable iron sulphides, which would otherwise lower the concentration of redox‐sensitive phosphorus, but cannot change the phosphorus retention in the long term. Because of internal phosphorus sources, the diversion of the Grabowhöfer Grenzgraben would result in no substantial changes in the level of trophy.