PubMed · 11273092
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
H J Eggers. 2001-02-10. Difficulties in polio eradication.. https://doi.org/10.1016/s0140-6736(05)71281-2
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Sulfoquinovose (SQ), a sulfonated sugar produced on a gigaton scale each year, contributes to global sulfur cycling, yet the microbes and pathways mediating its turnover in the environment have been inferred largely from genomic potential rather than direct activity. Here, we coupled incubations of environmental samples with 13C-labeled SQ to DNA-stable isotope probing to identify active SQ carbon assimilators across estuary, mangrove, and lake ecosystems. In estuarine communities, Vibrio and Cognatishimia incorporated SQ-derived 13C; Novosphingobium dominated in the mangrove, and Agrobacterium in the lake. Pure-culture experiments, coupled with comparative proteomics and gene knockout validation, demonstrated that Vibrio strains degrade SQ via modified sulfoglycolytic Embden-Meyerhof-Parnas and Entner-Doudoroff pathways to produce the environmentally significant organosulfur 2,3-dihydroxypropanesulfonate. Comparative genomic analyses suggested that closely related genome representatives of Novosphingobium, Cognatishimia, and Agrobacterium encode the sulfolytic SQ monooxygenase pathway. A global survey of aquatic microbial genomes indicated that over 9% harbor SQ degradation clusters, supporting a widespread distribution of bacterial SQ catabolic potential in aquatic environments.
The paper presents data on toxic heavy metals in sediments measured after two large chemical spills on the Tisza watershed area. On the basis of the results, it is concluded that significant volume, high concentration heavy metals reached the Upper Tisza and Szamos River sections. Based on the longitudinal distribution of the heavy metals in sediments, the primary sedimentation zones and concentration increase compared with reference site was determined. Results verified arrival of fresh spills of mining origin and superimposed pollution. Regarding to chronic ecotoxicological effects, degradation and bioaccumulation rates of heavy metals priority problems are associated with arsenic, lead, mercury and cadmium in the sediments of the Tisza and Szamos Rivers after the spills of Romanian origin in 2000. Results indicate that the biological availability of the various heavy metals significantly differ along the river, particularly upstream and downstream of the Tisza Lake. The recent investigation did not identify one single sample in which muscular metal concentration of pike (Esox lucius L.) exceeded the present Hungarian consumer guidelines. The investigated pike population on the Tisza River could be divided into characteristic subgroups based on muscular tissue metal concentrations (Cd, Hg, Pb, Cu and As), depending on the bioavailability of the metalloids at the different river sections. On the basis of the data evaluation, it is concluded that the present state of pollution on Tisza River indicates the potential for deterioration and need for further biomonitoring.
Conventional figures of merit such as limits of detection, signal to background ratio or repeatability, are used to determine the performance of pneumatic and ultrasonic sample introduction systems in an ultra-clean environment with an axially viewed inductively coupled plasma-atomic emission spectrometry and multichannel detection. We observed that the ultrasonic nebuliser offered a large improvement of signal intensity (10-133 greater) compared to a cyclone chamber coupled with a pneumatic Meinhard nebuliser. This improvement is associated with an average increase of signal to background ratio by a factor 86 and an average decrease of detection limits by a factor 6. The improvement factors generally depend on the element and for the same element on spectral lines. Typically, the observed values of detection limits in this work are lower than those published and obtained in non-ultra-clean conditions. The results emphasize that the environmental conditions of cleaning and analysis are essential to avoid and control cross contamination of the samples and hence to obtain low detection limits.