102 research outputs found
Assessment of the efficacy of an advanced tertiary sewage treatment plant to remove biologically active chemicals using endocrine and genotoxicity bioassays
There has been much effort to assess the efficacy of sewage treatment plants to remove chemicals with estrogenic activity, but other modes of toxicity have received less attention. This study assessed the efficacy of advanced tertiary technologies to remove estrogen receptor (ER), aryl hydrocarbon receptor (AhR), retinoic receptor (RAR) agonists and genotoxicity using recombinant gene bioassays. Untreated sewage contained ER, AhR and RAR agonists and was genotoxic. Activated sludge treatment removed over 69% of the ER, AhR and RAR aqueous phase activities. Ozonation and biologically activated carbon processes removed genotoxicity and most receptor agonists to below detection limits. Estrogenic activity was associated with the semi-polar fraction of the aqueous phase and non-polar phase of the influent (maximum 30%). AhR and RAR activities were found in both the aqueous and particulate phases of influent. Only RAR activity was frequently found in the polar fraction of aqueous and particulate phases of the process effluent. In the influent, the greatest RAR activity was found in the polar fraction of the aqueous phase (>65%). Genotoxic activity was detected in all influent fractions but rapidly decreased. The results showed that ER, AhR and RAR agonists were greatly reduced by the advanced tertiary treatment processes
The benefits of participatory methodologies to develop effective community dialogue in the context of a microbicide trial feasibility study in Mwanza, Tanzania
BACKGROUND: As part of a microbicide trial feasibility study among women at high-risk of HIV and sexually transmitted infections in Mwanza City, northern Tanzania we used participatory research tools to facilitate open dialogue and partnership between researchers and study participants. METHODS: A mobile community-based sexual & reproductive health service was established in ten city wards. Wards were divided into seventy-eight geographical clusters and representatives at cluster and ward level elected in a process facilitated by the projects Community Liaison Officer. A city-level Community Advisory Committee (CAC) with representatives from each ward was established. Workshops and community meetings at ward and city-level were conducted to explore project-related concerns using tools adapted from participatory learning and action techniques such as listing, scoring, ranking, chapatti diagrams and pair-wise matrices. RESULTS: Key issues identified included beliefs that blood specimens were being sold for witchcraft purposes; worries about specula not being clean; inadequacy of transport allowances; and delays in reporting laboratory test results to participants. To date, the project has responded by inviting members of the CAC to visit the laboratory to observe how blood and genital specimens are prepared; demonstrated the use of the autoclave to community representatives; raised reimbursement levels; introduced HIV rapid testing in the clinic; and streamlined laboratory reporting procedures. CONCLUSIONS: Participatory techniques were instrumental in promoting meaningful dialogue between the research team, study participants and community representatives in Mwanza, allowing researchers and community representatives to gain a shared understanding of project-related priority areas for intervention
Déplacement isotopique relatif dans le spectre d'arc du tungstène. structure hyperfine du niveau 5d5 6s 7s3 de WI
Optical isotope shifts of the five stable isotopes of tungsten ( 180W, 182W, 183W, 184W and 186 W) and the 183W hyperfine structure have been measured for the two lines λ =4 982 Å and λ=4 269 Å of WI using a Fabry-Pérot spectrometer. The hyperfine constant a6s of the 6s electron has been evaluated and its value compared to theoretical predictions. The result shows an important effect of core polarisation for the d5 s 7S3 level. A comparison was made of the mass shifts for the two transitions as well as of the field shifts. Assuming that the specific shift of the d4 s2-d 4 sp transition is negligible, one finds a specific shift of - 6,7 mK for the d5 s-d3 s2 p transition for the 184W-186W isotope pair. A Hartree-Fock calculation gives a satisfactory explanation of the signs and of the orders of magnitude of the observed mass and field shifts.Les déplacements isotopiques des cinq isotopes stables du tungstène ( 180W, 182W, 183W, 184W et 186 W) et la structure hyperfine de l'isotope 183W ont été mesurés sur les deux raies λ = 4 982 Å et λ = 4 269 Å de WI à l'aide d'un spectromètre Fabry-Pérot. La constante hyperfine monoélectronique a 6s a été évaluée : la comparaison de cette valeur expérimentale aux prévisions théoriques fait apparaître un important effet de polarisation du coeur pour le niveau d5 s 7S3. Les effets de masse spécifiques ainsi que les effets de volume des deux transitions étudiées sont comparés : en admettant que l'effet spécifique de la transition d 4 s2-d4 sp est négligeable on trouve que celui de la transition d5 s-d3 s2 p vaut - 6,7 mK pour le couple 184W, 186W. Un calcul de Hartree-Fock donne une interprétation correcte des signes et des ordres de grandeur des effets de masse et de volume observés
Sur quelques données histochimiques et physiologiques concernant des champignons levuriformes
Counts count
Abstract. Based on the 2006 edition of the Model Size Metrics workshop, we believe that counts are undervalued as useful model metrics. In this position paper, we provide arguments from the literature so as to consider counts as important metrics for the model measurement. We then state associated issues and sketch a model-driven framework to raise the abstraction level of the implementation of model metrics, starting with count metrics.
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