For negative controls, a field blank was prepared for each POCIS site and treated identically to POCIS extractions (Alvarez 2010).
To measure estrogen equivalents (relative to 17[beta]-estradiol) of the analytes present in the POCIS extracts, we performed a bioluminescent yeast estrogen screen (BLYES) (Sanseverino et al.
At 1 dpf, groups of 5xERE:GFP transgenic zebrafish embryos were exposed for 3-4 days to POCIS extracts collected from 19 locations in the Shenandoah River watershed and the Allegheny, Delaware, and Susquehanna Rivers (Figure 1; see also Supplemental Material, Table S1).
POCIS sampling provides a time-weighted average of chemical exposure over several weeks, whereas discrete sampling provides a snapshot of chemical exposure at a single point in time.
In this study, the POCIS discs had a standard configuration, that is, 180 [cm.sup.2] sampling surface area per gram of sorbent .
Figure 4 shows the POCIS and deployment steel canister.
Recovery of Chemical Residues from POCIS. Procedures for the recovery of the sequestered chemical residues from the deployed POCISs are described in detail by Bueno et al.
Another important message from this study is that passive sampling (or POCIS) was more efficient than grab sampling, at least qualitatively, in monitoring of the antibiotics in water environment.
Results: of 305 patients with proven or probable cerebral infarction, severe (70-99%) ipsilateral carotid stenosis was found in 16 (16%) of the 101 with partial anterior circulation infarct (PACI), four (4%) of the 100 with total anterior circulation infarct (TACI), none of the 80 with lacunar infarct (LACI) and one (4%) of the 24 with posterior circulation infarct (POCI).
Conclusion: these findings suggest that ipsilateral carotid disease is an important cause of stroke for those with anterior circulation infarcts but not for those with LACI or POCI. Subjects with PACI should be referred for early carotid imaging to identify those with severe disease who may be suitable for elective carotid surgery.
Patients with isolated motor or sensory deficits, or sensorimotor strokes or ataxic hemiparesis were classified in the lacunar infarct (LACI) group and those with brainstem or cerebellar signs in the posterior circulation infarct (POCI) group.
Severe ipsilateral carotid stenosis was found in 16 (16%; 95% CI 9-23%) of the PACI group, four (4%; 0-8%) of the TACI group, none (0%; 0-4%) of the LACI group and one (4%; 0-8%) of the POCI group ([chi square] P [is less than] 0.05).