Nutrient capture in an Iowa farm pond: Insights from high-frequency observations.

Shallow constructed ponds are abundant landscape features in the midwestern United States, suggested as an edge of field best management practice (BMP) in voluntary nutrient reduction strategies. The efficacy of such features is highly uncertain, however, and previous studies have lacked sufficient temporal resolution to determine N and P removals during critical periods of transport. We utilized high-frequency in-situ measurements and flow-weighted grab sampling to determine water and nutrient budgets for a typical constructed "farm pond" in central Iowa situated within the Iowa Southern Drift Plain. Our monitoring approach yielded insight into in-stream nitrogen processing and the relative importance of transport-vs. supply-limited N delivery. Diel patterns in NO3-N observed during early Spring, prior to canopy closure, revealed that in-stream primary production and NO3-N assimilation can influence downstream N delivery in a stream with nitrate pollution (mean annual NO3-N of nearly 5 mg/L). Analysis of discharge-concentration hysteresis for NO3-N showed a shift from transport to supply limitation for NO3-N delivery over the growing season, influenced by antecedent moisture, with wet antecedent conditions leading to supply limitation. Significant NO3-N removal (64% of 19.8 kg/ha inputs) occurred within the 4.2 ha pond (230 ha watershed), but total N removal was much lower (36% removal of 22.3 kg/ha inputs). The lower total N removal highlights the importance of both particulate N and dissolved organic N and ammonia export to the N budgets of hypereutrophic small ponds. Total P removal in the pond was only 8% of 2.3 kg/ha inputs, likely due to internal loading of recent and legacy sedimentary P within the pond. High-flow events dominated N and P inputs, during which removal efficacy of the pond was significantly diminished. Poor process performance during critical moments may partially explain lower than expected water quality improvements post-BMP implementation. Accordingly, shifting hydroclimatic regimes (e.g., frequency of intense rainfall events) will impact the efficacy of small ponds and other edge of field BMPs for nutrient reduction.

Do Steroids Matter? A Retrospective Review of Premedication for Taxane Chemotherapy and Hypersensitivity Reactions.

PURPOSE: Despite the widespread use of the taxanes paclitaxel and docetaxel for a variety of cancers and their well-known association with hypersensitivity reactions (HSRs), there is still significant variation in the prescribing practices of steroids for premedication. Premedication almost always includes dexamethasone, which can be associated with multiple adverse effects if taken for extended periods of time. This study reviews the pattern of steroid premedication in patients who received paclitaxel or docetaxel at Stanford Cancer Institute between January 2010 and June 2020. METHODS: We used an electronic query of the electronic medical record followed up with a manual review of patient charts to ask whether we could find a correlation between steroid premedication dosing and the incidence or severity of HSRs with the first taxane dose. Variables considered included steroid dose and route, dose and type of taxane, clinical cancer group, sex, and race. RESULTS: Five thousand two hundred seventeen patients were identified as having received paclitaxel or docetaxel, and 3,181 met criteria for our analysis. There were 264 (8.3%) HSRs. In adjusted multivariate analysis, we found no correlation of HSR rate or severity among any of the variables evaluated except gynecology oncology clinic patients, who had an increased risk (hazard ratio [HR] 1.34) of HSRs overall and high-grade HSRs (HR 2.34), and female patients, who had a higher rate of HSRs overall (HR 1.26), but not high-grade HSRs. CONCLUSION: Neither dexamethasone dose nor route correlated with subsequent HSRs. Given the potential for adverse events from repeated high-dose steroids, our findings suggest that routine use of lower doses, such as a single 10 mg dose of dexamethasone, as premedication for taxanes to prevent HSRs is preferable to the current prescribing guidelines.