Kinetics of nitrosation of the herbicide glyphosate.

The herbicide glyphosate was nitrosated by third-order kinetics to N-nitrosoglyphosate. The nitrosation at 25 degrees C was maximum at the reaction pH of 2.5 and had a pH-dependent rate constant of 2.43 M-2 sec-1. An activation energy of 9.5 kcal mole-1 also suggested that glyphosate is nitrosated very readily. Thiocyanate increased the rate 4.6 fold. The possibility of using these results to predict the formation of N-nitrosoglyphosate under normal agricultural practice is discussed.     

Organochlorines and heavy metals in the harbour seal Phoca vitulina from the German North Sea Coast

Samples of various tissues and organs from healthy, sick and dead harbour seals (Phoca vitulina) from the North German Waddensea collected during the years 1974–1976 were analysed for copper, zinc, total mercury, cadmium lead, and organochlorine pesticide residues (PCB, DDT, Lindane and Dieldrin). The investigations were carried out in order to increase our knowledge about the actual degree of heavy metal and organochlorine pesticide accumulation in these animals. The study was also directed towards a comparison of healthy and sick young seals and those found dead for a possible relation between the condition and concentration of polutants in the organs. There was great variation within all series of compounds investigated, but in general the analytical data obtained indicated that high amounts of heavy metals and organochlorine pesticides can be present even in young seals. An age-specific increase in the mercury and cadmium content in liver samples could be demonstrated. The results are compared with data published by British and Dutch authors for other North Sea regions, and with a few exceptions, no significant differences can be established: cadmium (kidney) and DDT (blubber) contents in areas off the British coast are usually higher than corresponding values for seals from the German coast. There was no clear evidence that the concentrations of any of the compounds investigated had negative effects on the health of the seals. However, possible combined effects cannot be excluded.     

Nitrogen, phosphorus, and potassium uptake by wheat and their distribution in soil following successive, annual compost applications

The overall objective of the present study was to determine the loading limits of composts that should be applied annually to irrigated wheat. We conducted a container experiment in a greenhouse during four years. It included eight treatments: sewage sludge compost (SSC) and cattle manure compost (CMC), each applied annually to a sandy soil, at rates equivalent to 3, 6, and 12 kg m(-2), and two controls, one fertilized and one unfertilized. Total dry matter (DM), grain production, and the amount of N, P, and K taken up by plants increased with increasing compost rate. Nitrogen uptake by the plants of the fertilized control was much higher than by the plants of the highest compost rate. Phosphorus and K uptake by the plants amended with the highest compost rate was much higher than by the fertilized control plants. Inorganic N quantity in the soil increased with increasing compost rate and with successive applications. The net N mineralization during the first year of wheat growth was very low, less than 3.5% of the applied organic N under all compost application rates. The contribution of the organic N mineralization increased during the second and third years. Most of the N increase in the compost treatment was found in the upper layer of 0 to 15 cm, whereas in the fertilized treatment N accumulated from the surface to the bottom of the container, 0 to 55 cm. The successive application of high rates of composts resulted in P and K accumulation in the soil profile.     

Collection and transportation cost of household solid waste in Kuwait

The specific aim of this funded research project was to examine and evaluate the efficiency and the effectiveness of the municipal solid waste collection and transportation system in the State of Kuwait. The contract resources of the seven contracting firms, the annual contract budgets, and the district area and population of each service contract are presented. Service efficiency and effectiveness indicators for each collection/disposal contract are also computed and discussed. The cost of collection and transportation of household waste in Kuwait is also compared with those of a number of urban areas in other nations. The low energy and manpower costs are mainly responsible for the favorable cost of management, collection and transportation of residential waste in Kuwait.     

New approaches to study the preservation of biopolymers in fossil bones

Tissues of living organisms are usually rapidly degraded after death. Nonetheless, the shape of organisms can sometimes be preserved under specific palaeoconditions. So far, biopolymers have rarely been found to be preserved in fossils. Here we show that not only DNA but also lipids are preserved in 500,000 year-old fossil bones, thus providing information on their biological source. Moreover, we suggest that lipid preservation follows similar mechanisms as DNA preservation, since fatty acids and DNA were found preserved in fossils in a mineral matrix associated form.An erratum to this article can be found at     

Revegetating fly ash landfills with Prosopis juliflora L.: impact of different amendments and Rhizobium inoculation

A revegetation trial was conducted to evaluate the feasibility of growing a legume species, Prosopis juliflora L., on fly ash ameliorated with combination of various organic amendments, blue-green algal biofertilizer and Rhizobium inoculation. Significant enhancements in plant biomass, photosynthetic pigments, protein content and in vivo nitrate reductase activity were found in the plants grown on ameliorated fly ash in comparison to the plants growing in unamended fly ash or garden soil. Higher growth was obtained in fly ash amended with blue-green algae (BGA) than farmyard manure or press mud (PM), a waste from sugar-processing industry, due to the greater contribution of plant nutrients, supply of fixed nitrogen and increased availability of phosphorus. Nodulation was suppressed in different amendments of fly ash with soil in a concentration-duration-dependent manner, but not with other amendments. Plants accumulated higher amounts of Fe, Mn, Cu, Zn and Cr in various fly ash amendments than in garden soil. Further, inoculation of the plant with a fly ash tolerant Rhizobium strain conferred tolerance for the plant to grow under fly ash stress conditions with more translocation of metals to the above ground parts. The results showed the potential of P. juliflora to grow in plantations on fly ash landfills and to reduce the metal contents of fly ash by bioaccumulation in its tissues.