Fungal variegatic acid and extracellular polysaccharides promote the site-specific generation of reactive oxygen species

Journal of Industrial Microbiology & Biotechnology - This study aims to clarify the role of variegatic acid (VA) in fungal attack by Serpula lacrymans, and also the generation and scavenging of...     

Marine invasion processes: interactions between native and introduced marsh snails

We test two hypotheses to explain the success of a biological invader in marshes on the Pacific coast of North America. The first hypothesis focuses on the competitive superiority of an invading species over native species; the second hypothesis focuses on the absence of ecological equivalents in the aboriginal biota, such that no competitive interactions are necessary to facilitate successful invasion. As a model system we experimentally manipulated the introduced pulmonate snail Ovatella myosotis and the native prosobranch snails Assiminea californica and Littorina subrotundata. Manipulations included pair-wise enclosures to determine of Ovatella depressed the growth of the native;species; pair-wise associations to determine whether or not snails demonstrated negative or positive clustering; removal experiments to see if native snails invaded regions occupied by Ovatella, and reciprocal transplants on a vertical gradient to determine the physiological breath of the target species. In addition to monitoring population abundances of all three species seasonally, dietary overlap of these gastropods was also examined. No evidence of competitive superiority by Ovatella was found. Ovatella possesses the physiological capacities to exist in a semiterrestrial environment and is therefore able to take advantage of resources unavailable to native gastropods. We conclude that the successful establishment of this Atlantic snail in the Pacific Northwest did not arise at the expense of native species.     

Reduction of Endotoxin Levels in Influenza Virus Vaccines by Barium Sulfate Adsorption-Elution

The level of endotoxin in influenza virus vaccine lots was reduced 10- to 20-fold after barium sulfate adsorption-elution. The amount of viral antigen lost was negligible.     

Is there a relationship between branched amino acid pool size and cell cycle inhibition in roots treated with imidazolinone herbicides?

Excised pea root tips were cultured in White's medium for 24 h and then treated for 12 h with one of the imidazolinone herbicides at 0.2, 2, 20, or 200 μM. Pursuit and Assert were almost ineffective in inhibiting the mitotic index (MI), except at the highest concentrations. Arsenal (ARS) and Scepter both showed good inhibition with 20 μM by 8 h. Adding all three branched amino acids (BAA) (VAL, ILE, and LEU) at 0.1 mM blocked herbicide action. Treatment with the BAAs singly had no protective effect. Experiments were performed to determine the BAA pool size and MI after an 8-h treatment with ARS at 2 and 200 μM and Chlorsulfuron (CS), a sulfonylurea herbicide, at 28 nM. Both CS and ARS at 200 μM inhibited the MI to almost 0 by 8 h. ARS at 2 μM inhibited the MI by about 40%. The BAA pool size in all three treatments was reduced by approximately 50%, whether the MI was totally blocked or not. The 1-mm root tips had a greater amount of VAL than did the mature portions of the roots, whereas ILE and LEU were slightly less in the root tip. Other soluble amino acids did not show consistent differences between herbicide-treated roots and controls. The implications of the pool size reduction, in instances where the MI was not totally inhibited, is discussed in light of new data from other laboratories on the mode of action of the imidazolinone herbicides.