Uptake of the cyanobacterial toxin cylindrospermopsin in Brassica vegetables

Toxin-producing cyanobacterial species are increasingly being found in freshwater systems. However, literature on the impact of many cyanobacterial toxins on plants is scarce. Cylindrospermosin (CYN), a secondary metabolite of cyanobacteria such as Cylindrospermopsis and Aphanizomenon species, is a potent hepatotoxin and protein synthesis inhibitor. Worryingly, CYN is increasingly found in surface and drinking water worldwide causing human and animal intoxications. Further, exposure of crop plants to CYN by irrigation with contaminated water has already been shown. Therefore, in this study, horticulturally important and highly consumed Brassica species were investigated to determine the level of CYN in the leaves after exposure of the roots to the toxin. Treatment of Brassica oleracea var. sabellica, Brassica juncea, and Sinapis alba under varying experimental conditions showed significant CYN uptake, with CYN levels ranging from 10% to 21% in the leaves compared to the CYN concentration applied to the roots (18–35 μg/l). In seedlings, CYN concentrations of up to 49 μg/g fresh weight were observed. Thus, crop plants irrigated with CYN-containing water may represent a significant source of this toxin within the food chain.     

Super connectivity of line graphs

The super connectivity κ^′ and the super edge-connectivity λ^′ are more refined network reliability indices than connectivity κ and edge-connectivity λ. This paper shows that for a connected graph G with order at least four rather than a star and its line graph L(G), κ^′(L(G))=λ^′(G) if and only if G is not super-λ^′. As a consequence, we obtain the result of Hellwig et al. [Note on the connectivity of line graphs, Inform. Process. Lett. 91 (2004) 7] that κ(L(G))=λ^′(G). Furthermore, the authors show that the line graph of a super-λ^′ graph is super-λ if the minimum degree is at least three.     

Air and water pollution control in crude tall oil manufacture in the pulp and paper industry

Pollution preventive measures should be built into the process when a new mill is designed; corrective measures must be taken on existing mills. For air pollution control, these measures consist essentially of enclosing all vessels that contain the black liquor from which the tall oil is recovered. Hoods are placed over storage tanks, sumps, heat exchangers, and other liquor-containing vessels. The hoods must be vented to a ductwork system that brings the off-gases to a central point for disposition. Typical devices to remove the offensive odors and particulate matter in the off-gases are wet scrubbers and incinerators. Evaporation can be used to concentrate liquids containing small amounts of contaminants to much smaller volumes and to concentrations that permit incineration. The lime kiln and recovery boiler of the typical Kraft mill commonly are used to burn the odorous gases, thus destroying the odors completely. Sometimes a separate incinerator is required. Water pollution is best prevented by careful design and operation of the various tall oil removal equipment, such as soap skimmers, level controls, and valving systems. In spite of great care in design and operation, some tall oil will enter the wastewater stream. The effluent treatment plant must be designed to take care of this residual biochemical oxygen demand load and, in some cases, provide for color reduction in the treated effluent. One of seven papers presented in the symposium “Tall Oil,” AOCS Meeting, New Orleans, May 1973.     

Ultrathin-layer horizontal high-resolution two-dimensional electrophoresis of legume seed proteins with intermediate protein staining

Summary Legume seed proteins extracted with urea-containing buffer are fractionated by high-resolution 2D-electrophoresis (urea-IEF x pore gradient SDS-PAGE), both dimensions in horizontal ultrathin-layer polyacrylamide gel slabs. High reproducibility is obtained, because the first dimension is performed in a slab gel, where a large number of protein samples are separated under identical conditions. The gel of the first dimension (IEF) is fixed, stained with Coomassie Brilliant Blue G 250, and destained before application to the second-dimension gel (SDS-PAGE). Prestaining of the focused proteins does not alter the protein pattern obtained after SDS electrophoresis. Thus, bands are made visible before separation in the second dimension, and the amount of Ampholine in the dye front is reduced during electrophoresis. The first-dimension gels can easily be stored in the destaining solution until they are run in the second dimension. As the proteins are fixed in the gel, there is no loss of proteins and defocusing of bands due to diffusion during the SDS-equilibration procedure. Loading of the dimensionstable gel strip onto the second dimension gel is a very easy operation, since the ultrathin gel strip adheres to a plastic foil and is simply laid into a moulded gel through. The gel strip is not imbedded with polymerizing acrylamide or agarose solution like in the conventional gel-rod-techniques, because a very good surface contact is obtained between the two flat gels.

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Ultradiinnschicht horizontale, hochauflösende Zweidimensional-Elektrophorese von Leguminosensamen-Proteinen mit Protein-Zwischenfärbung

Zusammenfassung Mit harnstoffhaltigen Tris-Glycin-Puffer extrahierte Leguminosensamen-Proteine werden mit der hochauflösenden 2D-Elektrophorese (Harnstoff-IEF x Gradientengel-SDS-Elektrophorese) aufgetrennt, wobei beide Dimensionen in horizontalen ultradünnen, auf Folie polymerisierten Polyacrylamid-Flachgelen durchgeführt werden. Die Flachgel-Focussierung (1. Dimension) erlaubt die Trennung einer großen Anzahl von Proteinproben unter identischen Bedingungen, wodurch die Reproduzierbarkeit von 2D-Elektrophoresen erheblich verbessert wird. Das Gel der ersten Dimension (IEF) wird mit Coomassie BB G 250 gefdrbt, bevor die einzelnen Gelstreifen für die zweite Dimension (Gradientengel-SDS-Elektrophorese) verwendet werden. Dies hat den Vorteil, daß die focussierten Proteine bereits vor dem zweiten Trennungsschritt sichtbar gemacht und zudem die Trägerampholyte in der Farbstoff Front bei der SDS-Elektrophorese stark vermindert werden. Die vorgefärbten Focussierungsgele können problemlos in der Entfärbelösung für die SDS-Gradientengel-Elektrophorese aufbewahrt werden. Der Proteinverlust und die Banden-diffusion bei der SDS-Aquilibrierung werden durch die Fixierung im Focussierungsgel verhindert. Das 2-D-Proteinmuster wird durch das Vorfärben der focussierten Proteine nicht verdndert. Die dimensionsstabilen, auf Folie polymerisierten Focussierungsstreifen lassen sich einfach handhaben und müssen nicht wie Rundgele an die zweite Dimension aufpolymerisiert werden. Der Gel-Gel-Kontakt der beiden Flachgele ist ohne weitere Hilfsmaßnahmen ausgezeichnet.