Comparison of residue levels of persistent organochlorine compounds in butter from Spain and from other European countries

Abstractp> Commercially available butter from Spain (n=36) and from other European countries (n=20) has been analyzed by high resolution gas chromatography with an electron capture detector for organochlorine contaminants. The results showed that both groups of samples have a similar pattern of these pollutants, but in all cases where significant differences in concentrations were found, Spanish samples presented higher values. This was especially notable for lindane (median values 11.6 vs. 3.0 ng/g wet weight), hexachlorobenzene (6.4 vs. 0.5) and ß‐hexachlorocyclohexane (3.1 vs. 1.2). Total PCBs showed no differences (5.4 vs. 6.6), but detailed analysis of congener composition indicated a higher presence in Spanish samples of the most persistent chlorinated PCBs. No sample presented levels of concern for any single organochlorine compound. It is interesting to note that consumption of butter in Spain is low so, although levels of organochlorines are higher than those found in other countries, consumers are less exposed through this foodstuff than in other European countries. These results also confirm the fact that environmental pollution by organochlorines is more important in Spain than in the rest of Europe.     

Aquatic Resource Conservation. The first Yangtze finless porpoise successfully born in captivity (4 pp)

Background As the sole freshwater subspecies of finless porpoise (Neophocaena phocaenoides), the Yangtze finless porpoise (N. p. asiaeorientalis) lives only in the middle and lower reaches of the Yangtze River and its appended Poyang and Dongting Lakes. As a result of human activity on the river, including over and illegal fishing, pollution, transportation and dam construction, the population of Yangtze finless porpoises has been steadily and rapidly decreasing during the past several decades, which leads the animal to be endangered. Methods For saving this unique animal from extinction, three corresponding measures, in situ conservation, ex situ conservation, and intensifying breeding research in captivity, were proposed and have been implemented since the 1980s. Results After successfully rearing the animals in captivity for almost nine years, the first Yangtze finless porpoise was successfully born in captivity on July 5, 2005. The calf is male, with a body length of 69cm. This is the first freshwater cetacean ever born in captivity. Conclusion The successful birth of this calf confirms that it is possible to breed the Yangtze finless porpoise in captivity. Furthermore, this will greatly benefit the conservation efforts, and also greatly bolster our on-going efforts to study the reproductivebiology of these animals. Recommendation More studies and efforts are expected to establish a sustainable, captive colony of the Yangtze finless porpoise, which will not only greatly expand our knowledge about the reproduction biology of this animal, but also help to redeem the wild population through a careful yearly 'soft releasing' process.     

Distribution of poly(β-hydroxybutyrate) and poly(ε-caprolactone)aerobic degrading microorganisms in different environments

To assess the capacity of the natural environment for degrading plastics, the populations of poly(p2826/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-hydroxybutyrate)(PHB)-and poly(p2826/xxlarge949.gif" alt="epsi" align="BASELINE" BORDER="0">-caprolactone)(PCL)-degrading aerobic microorganisms and their ratios to the total number of microorganisms in soil samples were estimated by the plate count method with agar medium containing emulsified PHB or PCL. The numbers of the degrading microorganisms were determined by counting colonies that formed clear zones on the plate. It was found that PHB- and PCL-degrading (depolymerizing) microorganisms are distributed over many kinds of material, including landfill leachate, compost, sewage sludge, forest soil, farm soil, paddy soil, weed field soil, roadside sand, and pond sediment. Of total colony counts, the percentages of PHB and PCL degrading microorganisms were 0.2–11.4 and 0.8–11.0%, respectively. The results suggest that many kinds of degrading microorganisms are present in each environment and that specific consortia differing in biodegradation capacity are constructed.     

Physical properties and biodegradability of blends containing poly(ε-caprolactone) and tropical starches

In order to assess feasibility of tropical starches (sago and cassava starches) as biodegradable plastic materials, blending with poly(p7254318448/xxlarge949.gif" alt="epsi" align="BASELINE" BORDER="0">-caprolactone) (PCL), a biodegradable polymer, was carried out. It was confirmed that the physical properties (tensile strength and elongation) of PCL/sago and PCL/cassava blends were similar to those of PCL/corn blend, suggesting that sago and cassava starches can also be blended with PCL for production of biodegradable plastic. However, the properties of all PCL/starch blends were still low compared with those of polyethylene. Enzymatic degradability evaluation showed that lipase degradation of PCL andp7254318448/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-amylase degradation of starch increased as the starch content in the blend increased. Burial test of the blends for 1, 3, and 5 months was carried out and the rate of degradation of the PCL/sago blend was confirmed to be slower than those of PCL/corn and PCL/cassava blends. Observation of the film blends structure by scanning electron microscope revealed that the starch was dispersed in a PCL continuous phase. Furthermore, changes in the film surface before and after enyzme treatments were observed.     

超声波/零价铁降解对硝基苯胺的试验研究

对在超声波、零价铁和超声波/零价铁(U/Fe0)等体系中对硝基苯胺的降解规律进行了研究。研究结果表明,对硝基苯胺在超声波作用下,降解规律符合一级反应动力学模型,但超声波对高浓度的对硝基苯胺降解效果较差。在U/Fe0体系中,超声波和零价铁对降解对硝基苯胺具有协同作用,对硝基苯胺降解速率显著提高。降解机理显示,对硝基苯胺在零价铁表面上发生原电池反应,被还原为对苯二胺,在超声波作用下进一步降解。在U/Fe0体系中添加Cu2+,形成Fe/Cu原电池,可进一步促进对硝基苯胺的降解速率,降解效率优于铸铁屑形成的Fe/C原电池。     

Characterization and enzymatic degradation of a cross-linked bacterial polyester

The bacterial polyester, poly(p1/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-hydroxybutyrate-co-p1/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-hydroxyvalerate) (PHB/V), was cross-linked with 1, 5, 7, 10, 20, and 30 wt% benzoyl peroxide by thermal decomposition reactions. Solvent extractions were carried out to determine the cross-linked fractions of the films. The sol/gel data were used to estimate cross-link densities. Films of PHB/V cross-linked with 10% benzoyl peroxide were placed in contact with purified depolymerase A secreted byP. lemoignei. These samples exhibited weight loss rates which were half that of un-cross-linked PHB/V, but the network was degraded completely by the enzyme. The results of this study suggest that anendo-type enzymatic degradation may occur, in addition to theexo-type activity, which is normally presumed to occur with theP. lemoignei depolymerase system.     

Are the Curative Properties of ‘Black Mud’ from the Dead Sea Due to the Presence of Bitumen (Asphalt) or Other Types of Organic Matter?

Deep black clayey sediments of the Dead Sea, previously covered with water at times of higher sea level, are being mined for therapeutic purposes and for the preparation of cosmetic products under the name pv46n2p1m9p3k131/xxlarge8216.gif" alt="lsquo" align="BASELINE" BORDER="0">Black Mudpv46n2p1m9p3k131/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0">. It was claimed that the beneficial properties are due to the presence of bitumen (asphalt) as attested by the colour. Less commonly, the curative properties have been ascribed to humic acids or to organic matter derived from algae in the lake. Asphalt from the Dead Sea has been of major economic importance to the region and was used as a medication for 2000 years until the mid-20th century. Geochemical analysis of the Black Mud showed that it contains relatively little organic matter (ca. 0.6–0.8% organic carbon) and that the organic matter is mostly derived from the land masses surrounding the lake. Asphalt was totally absent and the concentration of humic acids very low. The black colour of the mud is rather due to the poorly crystallised iron sulphides. Based on this, the therapeutic properties of the mud are ascribed to its content of reduced sulphur species, its physical and chemical properties and possibly its brine content, but not to the presence of organic matter.