A predictive model for freshwater bioassessment (Mondego River,Portugal)

We sampled macroinvertebrates at 75 locations in the Mondego river catchment, Central Portugal, and developed a predictive model for water quality assessment of this basin, based on the Reference Condition Approach. Sampling was done from June to September 2001. Fifty-five sites were identified as “Reference sites” and 20 sites were used as “Test sites” to test the model. At each site we also measured 40 habitat variables to characterize water physics and chemistry, habitat type, land use, stream hydrology and geographic location. Macroinvertebrates were generally identified to species or genus level; a total of 207 taxa were found. By Unweighted Pair Group Method with Arithmetic mean (UPGMA) clustering and analysis of species contribution to similarities percentage (SIMPER), two groups of reference sites were established. Using Discriminant Analysis (stepwise forward), four variables correctly predicted 78% of the reference sites to the appropriate group: stream order, pool quality, substrate quality and current velocity. Test sites’ environmental quality was established from their relative distance to reference sites, in MDS ordination space, using a series of bands (BEAST methodology). The model performed well at upstream sites, but at downstream sites it was compromised by the lack of reference sites. As with the English RIVPACS predictive model, the Mondego model should be continually improved with the addition of new reference sites. The adaptation of the Mondego model methodology to the Water Framework Directive is possible and would consist mainly of the integration of the WFD typology and increasing the number of ellipses that define quality bands. Handling editor: K. Martens     

Arsenic Bioaccumulation in Freshwater Fishes

The arsenic ambient water quality criterion (AWQC) for protection of human health via ingestion of aquatic organisms is currently 0.14 μ g/L. This AWQC is derived using a bioconcentration factor (BCF) of 44, which is a consumption-weighted average based on two data points for oysters and fish that was proposed by the U.S. Environmental Protection Agency in 1980 for broad application to freshwater and marine environments. This BCF is based on the assumption that bioaccumulation is a simple linear function of the exposure concentration. In the nearly quarter of a century since this BCF was promulgated, there have been additions to the arsenic bioaccumulation database and a broader scientific understanding of bioaccumulation mechanisms and how they can be applied to estimating tissue concentrations in aquatic organisms. From this database, we identified 12 studies of arsenic bioaccumulation in freshwater fishes in order to explore differences in laboratory-generated BCFs and field-generated bioaccumulation factors (BAFs) and to assess their relationship to arsenic concentrations in water. Our analysis indicates that arsenic concentrations in tissue and arsenic BAFs may be power functions of arsenic concentration in water. A power function indicates that the highest BCF values may occur at low background levels and may decrease as environmental concentrations increase above the ambient range.     

Wood preservation hygiene and environment in the lime-light of actually

Summary Under the ?Bois plus? scheme, the CTBA is currently developing a third party certification, based on the Scrivener law, with the aim of defending the consumers' interests. At this early stage, wood preservatives and treated wood are checked for the efficacy of treatments in order to ensure the stability and security of works in buildings and civil engineering. According to the different classes of risks in service, ?Bois plus? provides the most adeguate level of protection. In the close future, the industry is planning to incorporate, with the help of the CTBA and experts, health criteria within the frame of the ?Bois plus? certification scheme. The means could beSafety indexes, which are objectives of quality for professionals.Safety indexes are concentrations of substances in wood which can be taken as safe for humans and the general environment, while still toxic for the wood pests. This attractive experience aims to make with the brandname ?Bois plus? a synonym of efficacy and safety. This approach meets the essential requirements 1, 3, 4 of the 89/106 EEC directive: mechanical resistance and stability/hygiene, health and environment/safety in use.     

A comparison of three noise reduction procedures applied to bird vocal signals

ABSTRACT.   Recordings of avian vocal signals in natural habitats include ambient noise. Often this background noise corrupts across all frequencies and is of substantial amplitude. Reducing this ambient noise to prepare vocal signals for playback stimuli or to remove habitat-specific noise signatures prior to analyzing a signal's acoustic characteristics can be useful. We conducted experimental evaluations of three noise reduction procedures to determine their effectiveness. We embedded two bird vocalizations ("clean" signals) in four kinds of natural noise, resulting in eight noise-signal combinations. We then applied three noise reduction procedures (Noise Profile, Band Pass, and Noise Estimate) to each of the embedded signals and compared the recovered signals to the original (clean) signals. Noise Profile filtering was effective in reducing noise and returning fairly high-quality signals from even severe levels of masking noise. The other two noise reduction procedures did not perform as well. For the two most corrupting maskers, however, Noise Profile filtering also altered the signal properties by reducing signal amplitude at those frequencies containing high levels of noise. Apart from this loss of amplitude, the quantitative features of the filtered signals were similar to those of the original model sounds. We conclude that Noise Profile filtering produces good results for cases where noise is approximately constant over the signal duration and the signal intensity exceeds noise intensity over the frequencies of interest.     

Effects of stormwater sewer discharges on the aquatic community in urban canals in Lelystad

In urban areas with a separate sewerage system, the stormwater runoff is discharged into surface waters. A study on the effects of stormwater sewer discharges on the composition of the aquatic community in urban waters was carried out in two areas with a primarily residential use in the new town of Lelystad. The aquatic organisms considered included hydrophytes, epiphytic diatoms, filamentous algae and macroinvertebrates.The results indicate that the stormwater sewer discharges cause a slight change in the composition of the aquatic community. The water in the urban surface waters can be characterized as eutrophic and - toa-mesosaprobic. Near stormwater sewer outfalls the water tends to the more polluteda-mesosaprobic state. The shifts in the composition of the aquatic community could be traced primarily on the basis of a number of epiphytic diatoms and macroinvertebrates (in particular some Diptera and Trichoptera). Most hydrophytes, filamentous algae and the remaining epiphytic diatoms and macroinvertebrates (in particular water beetles and water mites) turned out to be of little or no use in this respect.Because the investigation was carried out in an unusually dry summer, the results probably underestimate the effects of stormwater discharges on the aquatic community.     

Some improvements in the quality of NAA procedures and the reliability of the results

After considering the need for quality control in NAA, the concept of quality in NAA procedures themselves is discussed, and some important factors identified. Two approaches to improve quality are then described in more detail. The first concerns the unique ability of NAA using different isotopic reactions and different modes (INAA/RNAA) to provide independent data sets in the same laboratory, thus allowing internal validation or crosschecking. The second discusses the need for chemical yield measurements in RNAA and the advantages of the radioisotopic tracer technique. Some recent advances and further possibilities for this use of tracers are listed.     

青皮核桃采后病害生防菌贝莱斯芽胞杆菌XRD006全基因组分析及防治效果研究

【目的】探究生防菌贝莱斯芽胞杆菌(Bacillus velezensis) XRD006对青皮核桃采后病害的生防能力及其贮藏保鲜效果,解析菌株的基因特性和次级代谢产物,了解菌株的抑菌机制。【方法】通过抑菌试验确定XRD006对青皮核桃采后病原菌的抑制能力。利用活体抑菌及贮藏试验探究生防菌对青皮核桃采后病原菌的抑制能力及对青皮核桃贮藏品质的影响。以全基因组测序了解菌株XRD006的基因组特征及潜在抑菌相关基因;利用antiSMASH软件预测XRD006的次级代谢产物;结合比较基因组学分析XRD006和贝莱斯芽胞杆菌标准株FZB42、SQR9之间的共线性关系和次级代谢产物基因簇差异。利用高效液相色谱(high performance liquid chromatography,HPLC)和质谱鉴定XRD006次级代谢产物并通过牛津杯法测定其抑菌能力。【结果】抑菌试验表明菌株XRD006对青皮核桃采后病原菌隐秘刺盘孢(Colletotrichum aenigma)、暹罗炭疽菌(Colletotrichum siamense)、葡萄座腔菌(Botryosphaeria dothidea)和藤仓...     

Interlaboratory Reproducibility In Reporting Inadequate Cervical Smears—A Multicentre Multinational Study

A set of 300 vaginal smears was interpreted by 13 cytologists from six European laboratories, who were requested to report inadequate and suboptimal smears. the set had been appropriately seeded to reach approximately 10% inadequate and 20% suboptimal smear frequency. According to the majority report, 230 smears were classified as adequate (76.7%), 43 as inadequate (14.3%), and 27 as suboptimal (9.0%). Agreement with the majority report ranged from 52% to 91% (average 78%). Kappa statistics for reporting inadequate smears showed a high level of agreement for five cytologists, and fair to good agreement for eight. In contrast, K statistics for reporting suboptimal smears showed fair to good agreement with the majority report only in five instances, whereas agreement was poor for eight cytologists. ‘Inadequate smear’rates may be used to compare the quality of smears received in different laboratories, as there is a high level of agreement among cytologists as to what constitutes an inadequate smear. However, this is not true for ‘suboptimal smear’ rates, and more precise reporting criteria must be defined and tested if an intermediate category is to be retained to report poor quality smears: more precise reporting criteria must be defined and tested if an intermediate category is to be retained to report poor quality smears. Une série de 300 frottis cervico-vaginaux a été examinee par 13 cytologistes appartenant à 6 laboratoires européens auxquels il avait été demandé de signaler les frottis inadéquats et sub-optimaux. Cette série de frottis a été constituée de façon à atteindre approximativement une fréquence de 10% de frottis inadéquats et de 20% de frottis sub-optimaux. Si I'on considère les réponses faites par la majorité des cytologistes, 230 frottis ont été classés adéquats (76,7%), 43 classés inadéquats (14,3%), et 27 comme sub-optimaux (9,0%). La concordance avec les réponses de la majorité des cytologistes varie de 52%à 91% (moyenne 78%). Concernant le signalement des frottis inadéquats, le test Kappa est excellent pour 5 cytologistes et moyen à bon pour les 8 autres. Au contraire, pour le signalement des frottis sub-optimaux, le test Kappa montre un accord moyen à bon avec les réponses de la majorité seulement dans 5 cas alors que I'agrément est mauvais pour 8 cytologistes. La fréquence des frottis inadéquats peut être utilisée pour comparer la qualité de prélèvement du frottis dans différents laboratoires, alors que les comparaisons de la fréquence des frottis sub-optimaux sont discutables, du fait d'un biais de diagnostic évident. Des critéres plus précis pour le signalement des frottis sub-optimaux doivent étre définis et testés si cette catégorie doit être retenue pour rapporter les frottis de mauvaise qualité. 300 Abstriche wurden durch 13 Zytologen aus 6 europäischen Laboratorien hinsichtlich der Kriterien ‘unbrauchbar’und ‘suboptimal’beurteilt. Die Sammlung enthielt etwa 10% unbrauchbare und 20% suboptimale Präparate. Mehrheitlich wurden 230 Abstriche als auswertbar (76,7%), 43 als unbrauchbar (14,3%) und 27 als suboptimal (9,0%) bezeichnet. Die Statistik ergab hinsichtlich der unbrauchbaren Abstriche eine ausgezeichnete Ûbereinstimmung für 5 und eine gute Ûbereinstim-mung für 8 Zytologen. Demgegenüber zeigte sich hinsichtlich der Beurteilung suboptimal nur 5mal eine gute und 8mal eine schlechte Ûbereinstimmung. Damit ist die Kategorie suboptimal ungeeignet zum Vergleich und bedarf einer genaueren Definition wenn sie für die Qualitätskontrolle eingesetzt werden soll.