Alternating water sources to minimize contaminant accumulation in food plants from treated wastewater irrigation.

The use of treated wastewater (TWW) for agricultural irrigation is a critical measure in advancing sustainable water management and agricultural production. However, TWW irrigation in agriculture serves as a conduit to introduce many contaminants of emerging concern (CECs) into the soil-plant-food continuum, posing potential environmental and human health risks. Currently, there are few practical options to mitigate the potential risk while promoting the safe reuse of TWW. In this greenhouse study, the accumulation of 11 commonly occurring CECs was evaluated in three vegetables (radish, lettuce, and tomato) subjected to two different irrigation schemes: whole-season irrigation with CEC-spiked water (FULL), and half-season irrigation with CEC-spiked water, followed by irrigation with clean water for the remaining season (HALF). Significant decreases (57.0-99.8 %, p < 0.05) in the accumulation of meprobamate, carbamazepine, PFBS, PFBA, and PFHxA in edible tissues were found for the HALF treatment with the alternating irrigation scheme. The CEC accumulation reduction was attributed to reduced chemical input, soil degradation, plant metabolism, and plant growth dilution. The structural equation modeling showed that this mitigation strategy was particularly effective for CECs with a high bioaccumulation potential and short half-life in soil, while less effective for those that are more persistent. The study findings demonstrate the effectiveness of this simple and on-farm applicable management strategy that can be used to minimize the potential contamination of food crops from the use of TWW and other marginal water sources in agriculture, while promoting safe reuse and contributing to environmental sustainability.

Methylation and Demethylation of Emerging Contaminants Changed Bioaccumulation and Acute Toxicity in Daphnia magna.

Contaminants of emerging concern (CECs) in the environment undergo various transformations, leading to the formation of transformation products (TPs) with a modified ecological risk potential. Although the environmental significance of TPs is increasingly recognized, there has been relatively little research to understand the influences of such transformations on subsequent ecotoxicological safety. In this study, we used four pairs of CECs and their methylated or demethylated derivatives as examples to characterize changes in bioaccumulation and acute toxicity in Daphnia magna, as a result of methylation or demethylation. The experimental results were further compared to quantitative structure-activity relationship (QSAR) predictions. The methylated counterpart in each pair generally showed greater acute toxicity in D. magna, which was attributed to their increased hydrophobicity. For example, the LC50 values of methylparaben (34.4 ± 4.3 mg L-1) and its demethylated product (225.6 ± 17.3 mg L-1) differed about eightfold in D. magna. The methylated derivative generally exhibited greater bioaccumulation than the demethylated counterpart. For instance, the bioaccumulation of methylated acetaminophen was about 33-fold greater than that of acetaminophen. In silico predictions via QSARs aligned well with the experimental results and suggested an increased persistence of the methylated forms. The study findings underline the consequences of simple changes in chemical structures induced by transformations such as methylation and demethylation and highlight the need to consider TPs to achieve a more holistic understanding of the environmental fate and risks of CECs.

A potential role of caspase recruitment domain family member 9 (Card9) in transverse aortic constriction-induced cardiac dysfunction, fibrosis, and hypertrophy.

Macrophage- and monocyte-derived cytokines are elevated in the myocardium of pressure-overloaded hearts, where they play critical roles in pathological remodeling. Caspase recruitment domain family member 9 (CARD9) regulates macrophage cytokine secretion, but its role in a transverse aortic constriction (TAC) model of pressure overload has not been evaluated. To investigate whether CARD9 may serve as a valuable therapeutic target, wild-type (WT) and CARD9-knockout mice were subjected to 3 months of TAC, and then cardiac function, hypertrophy, and fibrosis were analyzed. The expression of protein markers of myocardial autophagy and nuclear factor kappa B signaling was also investigated. At 1 month after TAC, cardiomyocyte contractile dynamics were measured in a separate cohort to further assess contractility and diastolic function. In WT but not CARD9-/- mice, TAC resulted in severe cardiomyocyte contractile dysfunction at 1 month and functional decrements in fractional shortening at 3 months in vivo. Furthermore, CARD9-/- mice did not develop cardiac fibrosis or hypertrophy. CARD9-/- mice also had decreased protein expression of inhibitor of κB kinase-α/ß, decreased phosphorylation of p65, and increased expression of protein markers of autophagy. These findings suggest that CARD9 plays a role in pathological remodeling and cardiac dysfunction in mouse hearts subjected to TAC and should be investigated further.

Personal finances of residents at three Canadian universities.

OBJECTIVES: To address 3 research questions (What financial choices do residents make? Are the financial choices of residents similar to those of the general public? Are the financial choices of surgical residents reasonable?), we examined financial data from Canadian residents. METHODS: A written survey was administered to 338 residents (103 of them surgical residents) at 3 Canadian training institutions (University of Toronto, Queen's University and University of Manitoba). Resident household cash flows, assets and liabilities were characterized. Finances for residents were compared with those of the general public, by means of the Survey of Household Spending and Survey of Financial Security. RESULTS: Median resident income was 45,000 dollars annually (Can dollars throughout). With a working spouse, median household income was 87,500 dollars. Among residents, 62% had educational debt (median 37,500 dollars), 39% maintained unpaid credit-card balances (median 1750 dollars), 36% did not budget expenses, 25% maintained cash reserves <275 dollars, and 22% contributed neither to retirement nor nonretirement investments. Residents spent more on vehicles compared with members of the general public (median 17,500 dollars v. 10,720 dollars, p = 0.002) and on monthly housing (median 875 dollars v. 729 dollars, p < 0.001), respectively. Residents were more likely to carry student loans than people in the general population (61% v. 21%), more likely to carry vehicle loans (74% v. 29%) and less likely to carry credit-card debts (39% v. 50%, respectively). Surgical residents had income expectations after graduation higher than current billings justified. Fewer surgical (69%) than anesthesiology residents (88%, p < 0.05) contributed to Registered Retirement Savings Plans. CONCLUSIONS: From this limited sample, residents spend more than age- and income-matched members of the general public. Many residents save too little, fail to budget, and carry high educational and credit-card debts. Surgical residents' expectations of future income may be unrealistic. Further study is warranted.