Habitat Assessment of Non-Wadeable Rivers in Michigan

Habitat evaluation of wadeable streams based on accepted protocols provides a rapid and widely used adjunct to biological assessment. However, little effort has been devoted to habitat evaluation in non-wadeable rivers, where it is likely that protocols will differ and field logistics will be more challenging. We developed and tested a non-wadeable habitat index (NWHI) for rivers of Michigan, where non-wadeable rivers were defined as those of order ≥5, drainage area ≥1600 km 2 , mainstem lengths ≥100 km, and mean annual discharge ≥15 m 3 /s. This identified 22 candidate rivers that ranged in length from 103 to 825 km and in drainage area from 1620 to 16,860 km 2 . We measured 171 individual habitat variables over 2-km reaches at 35 locations on 14 rivers during 2000–2002, where mean wetted width was found to range from 32 to 185 m and mean thalweg depth from 0.8 to 8.3 m. We used correlation and principal components analysis to reduce the number of variables, and examined the spatial pattern of retained variables to exclude any that appeared to reflect spatial location rather than reach condition, resulting in 12 variables to be considered in the habitat index. The proposed NWHI included seven variables: riparian width, large woody debris, aquatic vegetation, bottom deposition, bank stability, thalweg substrate, and off-channel habitat. These variables were included because of their statistical association with independently derived measures of human disturbance in the riparian zone and the catchment, and because they are considered important in other habitat protocols or to the ecology of large rivers. Five variables were excluded because they were primarily related to river size rather than anthropogenic disturbance. This index correlated strongly with indices of disturbance based on the riparian (adjusted R 2 = 0.62) and the catchment (adjusted R 2 = 0.50), and distinguished the 35 river reaches into the categories of poor (2), fair (19), good (13), and excellent (1). Habitat variables retained in the NWHI differ from several used in wadeable streams, and place greater emphasis on known characteristic features of larger rivers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41269/1/267_2004_Article_141.pd

ICAR: endoscopic skull‐base surgery

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A Critical Assessment of the Golden Hour and the Impact of Procedural Timing in Stroke Thrombectomy

Previous studies in acute ischemic stroke have demonstrated the importance of minimizing delays to endovascular treatment and keeping thrombectomy procedural times at <30-60 minutes. The purpose of this study was to investigate the impact of thrombectomy procedural times on clinical outcomes. We retrospectively compared 319 patients having undergone thrombectomy according to procedural time (60 minutes) and time from stroke onset to endovascular therapy (≤6 or >6 hours). Clinical characteristics of patients with postprocedural intracranial hemorrhage were also assessed. Logistic regression was used to determine independent predictors of poor outcome at 90 days (mRS ≥3). Greater age (OR, 1.03; 95% CI, 1.01-1.06; = .016), higher admission NIHSS score (OR, 1.10; 95% CI, 1.04-1.16; = .001), history of diabetes mellitus (OR, 1.96; 95% CI, 1.05-3.65; = .034), and postprocedural intracranial hemorrhage were independently associated with greater odds of poor outcome. Modified TICI scale scores of 2c (OR, 0.11; 95% CI, 0.04-0.28; < .001) and 3 (OR, 0.15; 95% CI, 0.06-0.38; 6 hours was independently associated with increased odds of poor outcome (OR, 2.20; 95% CI, 1.11-4.36; = .024) in the final multivariate model (area under the curve = 0.820). Procedural time was not independently associated with clinical outcome in the final multivariate model ( > .05). Thrombectomy procedural times beyond 60 minutes are associated with lower revascularization rates and worse 90-day outcomes. Procedural time itself was not an independent predictor of outcome. While stroke thrombectomy procedures should be performed rapidly, our study emphasizes the significance of achieving revascularization despite the requisite procedural time. However, the potential for revascularization must be weighed against the risks associated with multiple thrombectomy attempts

Government Agencies as Mediators in Public Policy Conflicts

This study evaluates an attempt to develop a mediation program within a state environmental agency. A number of concerns arose during the agency\u27s efforts to use mediation, including the neutrality of mediators, the types of cases mediated, the voluntary participation of parties, and acceptance of the mediated agreement. These issues were examined through a case study of a conflict that was mediated by the agency. Based on issues in the case, criteria are suggested which help guard against the problems that arise when government agencies serve a mediating role. These criteria may be useful to any organization that contemplates using mediation to help resolve conflict