Lipase catalysed acylation of hydroxylamine and hydrazine derivatives

The lipase catalysed acylation of hydroxylamine-and hydrazine as well as their derivatives by octanoic acid is very efficient. Cross-linked crystals of Candida rugosa lipase (ChiroCLEC-CR) mediated the conversion of racemic ibuprofen into (S)-ibuproxam. A number of lipases also catalysed the condensation of hydrazine with an excess of octanoic acid giving N,N′-dioctanoylhydrazine. The hydrazide of 2-(4-isobutylphenyl)propanoic acid (ibuprofen), prepared by non-enzymatic reaction of ibuprofen methyl ester with hydrazine, acted as nucleophile towards several lipases that do not accept ibuprofen derivatives as acyl donor.     

River Red Gum (Eucalyptus camaldulensis Dehnh.) organic matter as a carbon source in the lower Darling River,Australia

The Darling River, in New South Wales, Australia, is a large semi-arid system with a highly variable flow regime, characterised by unpredictable events of flooding and drought. In large lowland rivers like the Darling, lateral (river-floodplain) interactions can greatly influence both physical and biological components of the system. The floodplain and riparian zone of the Darling River is dominated by River Red Gum (RRG), Eucalyptus camaldulensis. The large amount of organic matter they produce accumulates on the floodplain and on benches within the channel, and is subject to alternate periods of flooding and drying as a result of highly variable flows. This paper examines the effect of alternate periods of flooding and drying on the processing of E. camaldulensis organic matter. Results of the 6-month in situ field study, together with results from laboratory experiments comparing dissolved organic carbon (DOC) release from various RRG litter types, suggest that RRG leaves provide the most bio-available source of carbon to the system, while bark may be more important as a habitat for invertebrates and other fauna. Laboratory experiments exploring the effect of drying and re-flooding on litter breakdown and release of DOC suggested that the majority of DOC was released from RRG leaves in the first 24 h of inundation. Also, upon drying and re-flooding of the leaves, a smaller but significant release of DOC occurred. However, an alternative wet/dry cycle did not affect weight loss of the leaf litter. Results of the field and lab experiments suggest that RRG leaves represent an important source of carbon to the Darling River, with inputs being influenced by the highly variable flow regime.     

Ethnobotany ofAgave lecheguilla andYucca carnerosana in Mexico’s Zona ixtlera

In the drylands of northcentral Mexico campesinos known as ixtleros or talladores gather ixtle, a hard fiber derived from the uncultivated plants lechuguilla (Agave lecheguilla Torr.), and palma samandoca (Yucca carnerosana [Trel.] McKelv.). Ixtleros sell most of the fiber they collect, and the region in which ixtle is currently exploited for commercial purposes is called the Zona Ixtlera. Unsold fiber is converted into rope and brushes in ixtlero communities and used for a variety of purposes. Various parts of lechuguilla and palma samandoca are also employed to meet local construction, cleansing, and dietary needs.     

Ethical Responsibility for the Social Production of Tuberculosis

Approximately one in two hundred persons in the Marshall Islands have active tuberculosis (TB). We examine the historical antecedents of this situation in order to assign ethical responsibility for the present situation. Examining the antecedents in terms of Galtung’s dialectic of personal versus structural violence, we can identify instances in the history of the Marshall Islands when individual subjects made decisions (personal violence) with large-scale ecologic, social, and health consequences. The roles of medical experimenters, military commanders, captains of the weapons industry in particular, and industrial capitalism in general (as the cause of global warming) are examined. In that, together with Lewontin, we also identify industrial capitalism as the cause of tuberculosis, we note that the distinction between personal versus structural violence is difficult to maintain. By identifying the cause of the tuberculosis in the Marshall Islands, we also identify what needs be done to treat and prevent it.