Influence of Vegetated Wetlands on the Water Quality of Two Glacial Prairie Lakes

We investigated the influence of vegetated wetlands on water quality of two eastern South Dakota glacial prairie lakes. Surface water from a 5,880 ha pastured basin drains into a 90 ha upstream Typha wetland and enters Lake Enemy Swim passing 400 m through Typha-Scirpus littoral wetland. A second 1,290 ha basin characterized by row crops and pasture drains into a 260 ha open water slough entering L. Enemy Swim adjacent to Typha-Scirpus littoral wetland. Water enters Lake Cochrane from two smaller drainage basins. Water from a 180 ha basin consisting of a pasture and wet meadow enters the lake after passing about 100 m through Typha-Scirpus littoral wetland. A second basin consisting of 120 ha of mixed row crops, pasture and wetlands drains into an open water sediment retention pond and enters L. Cochrane after passing 50 m through Typha-Scirpus littoral wetland. At each lake, we measured water quality parameters in upstream drainages, in littoral wetlands, and at midlake sites in 1992 and 1993. In both lakes all forms of N were lesser and Fe were greater in concentration than all other sites in the drainages from upstream vegetated areas. Both N and P concentrations were greatest in the drainages from upstream open water areas resulting in small Si:P and Si:N ratios, and large N:Fe ratios. Concentrations of N and P decreased and Si:P and Si:N ratios increased passing through vegetated littoral wetlands, thus decreasing the likelihood of triggering phytoplankton shifts from desirable diatoms to undesirable bluegreen algal blooms

Influence of Vegetated Wetlands on the Water Quality of Two Glacial Prairie Lakes

We investigated the influence of vegetated wetlands on water quality of two eastern South Dakota glacial prairie lakes. Surface water from a 5,880 ha pastured basin drains into a 90 ha upstream Typha wetland and enters Lake Enemy Swim passing 400 m through Typha-Scirpus littoral wetland. A second 1,290 ha basin characterized by row crops and pasture drains into a 260 ha open water slough entering L. Enemy Swim adjacent to Typha-Scirpus littoral wetland. Water enters Lake Cochrane from two smaller drainage basins. Water from a 180 ha basin consisting of a pasture and wet meadow enters the lake after passing about 100 m through Typha-Scirpus littoral wetland. A second basin consisting of 120 ha of mixed row crops, pasture and wetlands drains into an open water sediment retention pond and enters L. Cochrane after passing 50 m through Typha-Scirpus littoral wetland. At each lake, we measured water quality parameters in upstream drainages, in littoral wetlands, and at midlake sites in 1992 and 1993. In both lakes all forms of N were lesser and Fe were greater in concentration than all other sites in the drainages from upstream vegetated areas. Both N and P concentrations were greatest in the drainages from upstream open water areas resulting in small Si:P and Si:N ratios, and large N:Fe ratios. Concentrations of N and P decreased and Si:P and Si :N ratios increased passing through vegetated littoral wetlands, thus decreasing the likelihood of triggering phytoplankton shifts from desirable diatoms to undesirable bluegreen algal blooms

Vorticity dynamics during the start-up phase of gravity currents

The flow during the start-up phase of two-dimensional gravity currents is investigated by numerical simulations. The focus of the study is on the dynamics of the initially vertical density interface which is deformed by the developing convective motion. Two different cases are considered, namely the lock-exchange flow and the release of a finite volume of dense fluid in deep surroundings. The viscous problem is addressed by direct numerical simulations based on the Boussinesq equations, which are integrated by high-order numerical schemes. The direct simulations are supplemented by vortex dynamics simulations using a vortex blob technique in order to study the underlying inviscid dynamics. Several distinct features of starting gravity currents are identified, among these the formation of start-up vortices very similar in nature to those observed for unstratified vortex sheets of finite extent. Moreover, the flow is shown to develop a pronounced Kelvin-Helmholtz–like instability at the interface, the details of which strongly depend on the ratio of buoyancy forces to viscous forces

Building the ACS Exams Anchoring Concept Content Map for Undergraduate Chemistry

The ability to coherently assess content knowledge throughout an entire undergraduate career represents a significant advantage for programmatic assessment strategies. Chemistry, as a discipline, has an unusual tool in this regard because of the nationally standardized exams from the ACS Exams Institute. These exams are norm-referenced and allow chemistry departments to make comparisons between the performance of their own students relative to national samples; however, currently there appears to be no systematic means for noting students’ content knowledge growth over a four-year degree. The Exams Institute is undertaking the task of organizing content along an anchoring concept or “big ideas” framework to facilitate this type of analysis

Quality control of B-lines analysis in stress Echo 2020

Background The effectiveness trial “Stress echo (SE) 2020” evaluates novel applications of SE in and beyond coronary artery disease. The core protocol also includes 4-site simplified scan of B-lines by lung ultrasound, useful to assess pulmonary congestion. Purpose To provide web-based upstream quality control and harmonization of B-lines reading criteria. Methods 60 readers (all previously accredited for regional wall motion, 53 B-lines naive) from 52 centers of 16 countries of SE 2020 network read a set of 20 lung ultrasound video-clips selected by the Pisa lab serving as reference standard, after taking an obligatory web-based learning 2-h module ( http://se2020.altervista.org ). Each test clip was scored for B-lines from 0 (black lung, A-lines, no B-lines) to 10 (white lung, coalescing B-lines). The diagnostic gold standard was the concordant assessment of two experienced readers of the Pisa lab. The answer of the reader was considered correct if concordant with reference standard reading ±1 (for instance, reference standard reading of 5 B-lines; correct answer 4, 5, or 6). The a priori determined pass threshold was 18/20 (≥ 90%) with R value (intra-class correlation coefficient) between reference standard and recruiting center) > 0.90. Inter-observer agreement was assessed with intra-class correlation coefficient statistics. Results All 60 readers were successfully accredited: 26 (43%) on first, 24 (40%) on second, and 10 (17%) on third attempt. The average diagnostic accuracy of the 60 accredited readers was 95%, with R value of 0.95 compared to reference standard reading. The 53 B-lines naive scored similarly to the 7 B-lines expert on first attempt (90 versus 95%, p = NS). Compared to the step-1 of quality control for regional wall motion abnormalities, the mean reading time per attempt was shorter (17 ± 3 vs 29 ± 12 min, p < .01), the first attempt success rate was higher (43 vs 28%, p < 0.01), and the drop-out of readers smaller (0 vs 28%, p < .01). Conclusions Web-based learning is highly effective for teaching and harmonizing B-lines reading. Echocardiographers without previous experience with B-lines learn quickly.info:eu-repo/semantics/publishedVersio

Coastal Upwelling Supplies Oxygen-Depleted Water to the Columbia River Estuary

Low dissolved oxygen (DO) is a common feature of many estuarine and shallow-water environments, and is often attributed to anthropogenic nutrient enrichment from terrestrial-fluvial pathways. However, recent events in the U.S. Pacific Northwest have highlighted that wind-forced upwelling can cause naturally occurring low DO water to move onto the continental shelf, leading to mortalities of benthic fish and invertebrates. Coastal estuaries in the Pacific Northwest are strongly linked to ocean forcings, and here we report observations on the spatial and temporal patterns of oxygen concentration in the Columbia River estuary. Hydrographic measurements were made from transect (spatial survey) or anchor station (temporal survey) deployments over a variety of wind stresses and tidal states during the upwelling seasons of 2006 through 2008. During this period, biologically stressful levels of dissolved oxygen were observed to enter the Columbia River estuary from oceanic sources, with minimum values close to the hypoxic threshold of 2.0 mg L−1. Riverine water was consistently normoxic. Upwelling wind stress controlled the timing and magnitude of low DO events, while tidal-modulated estuarine circulation patterns influenced the spatial extent and duration of exposure to low DO water. Strong upwelling during neap tides produced the largest impact on the estuary. The observed oxygen concentrations likely had deleterious behavioral and physiological consequences for migrating juvenile salmon and benthic crabs. Based on a wind-forced supply mechanism, low DO events are probably common to the Columbia River and other regional estuaries and if conditions on the shelf deteriorate further, as observations and models predict, Pacific Northwest estuarine habitats could experience a decrease in environmental quality

The effect of teriparatide treatment on circulating periostin and its relationship to regulators of bone formation and BMD in postmenopausal women with osteoporosis

Context: Treatment of postmenopausal osteoporosis with teriparatide (PTH 1-34) increases bone formation and improves bone microarchitecture. A possible modulator of this mechanism of action is periostin. In vitro experiments have shown that periostin may regulate osteoblast differentiation and bone formation through Wnt signaling. Periostin secretion is increased by PTH in preclinical models, but the effect of teriparatide treatment of postmenopausal osteoporosis on periostin is not currently known. Objectives, to: i) determine the effect of teriparatide treatment on circulating levels of periostin and other regulators of bone formation and ii) investigate how changes in periostin relate to changes in bone turnover markers, regulators of bone formation and bone mineral density. Participants and design: 20 women with postmenopausal osteoporosis, a two-year open-label single-arm study. Intervention: Teriparatide 20 mcg was administered by subcutaneous injection daily over 104 weeks. Periostin, sclerostin and DKK-1, PINP and CTX were measured in fasting serum collected at baseline (two visits) then at weeks 1,2,4,12,26,52,78 and 104. BMD was measured at the lumbar spine, total hip and femoral neck by DXA. Results: Periostin levels increased by 6.6% (95% CI -0.4, 13.5) after 26 weeks teriparatide treatment and significantly by 12.5% (95% CI 3.3,21.0, P<0.01) after 52 weeks. Change in periostin was positively correlated with change in lumbar spine BMD at week 52 (r=0.567(95% CI 0.137,0.817), P<0.05) and femoral neck BMD at week 104(r=0.682(95% CI 0.261,0.885), P<0.01). Conclusion: Teriparatide therapy increases periostin secretion; it is unclear whether this increase mediates the effect of the drug on bone