Activity

  • Iqbal posted an update 7 months, 2 weeks ago

    The mathematical framework is demonstrated for a drinking water production facility. Radon activities for the six monitored extraction wells ranged between 4,400 and 8,400 Bq/m³. Estimated mean aquifer residence times for the wells range from less then 5 days to 110 days and strongly depend on i) the type of residence time distribution model (exponential, gamma or piston flow), ii) the mixing ratio between bank filtrate and local groundwater, and iii) the heterogeneity in the groundwater endmember. By accounting for mixing processes, we can show that radon can be used beyond the “5-fold half-life” (~20 days) commonly described in the literature as the upper limit for age dating purposes for radon. This method provides a simple and cost-efficient way to quantify residence times of bank filtrate on a regular basis without any addition of external substances to the aquifer.This study presents the first large-scale assessment of cyanobacterial frequency and abundance of surface water near drinking water intakes across the United States. Public water systems serve drinking water to nearly 90% of the United States population. Cyanobacteria and their toxins may degrade the quality of finished drinking water and can lead to negative health consequences. Satellite imagery can serve as a cost-effective and consistent monitoring technique for surface cyanobacterial blooms in source waters and can provide drinking water treatment operators information for managing their systems. This study uses satellite imagery from the European Space Agency’s Ocean and Land Colour Instrument (OLCI) spanning June 2016 through April 2020. At 300-m spatial resolution, OLCI imagery can be used to monitor cyanobacteria in 685 drinking water sources across 285 lakes in 44 states, referred to here as resolvable drinking water sources. First, a subset of satellite data was compared to a subset of responses (nobserving changes at these source waters; on average, a decade of satellite imagery would be required for observed environmental trends to outweigh variability in the data. However, five source waters did demonstrate a sustained short-term trend, with one increasing in cyanobacterial abundance from June 2016 to April 2020 and four decreasing.Conservation identities of farmers in the Maumee River watershed, derived from farmer surveys, were embedded into a SWAT watershed model. This was done to improve the representation of the heterogeneity among farmers in the decision-making process related to the adoption of conservation practices. Modeled farm operations, created with near field-level Hydrologic Response Units (HRUs) within the SWAT model, were assigned a modeled primary operator. Modeled primary operators held unique conservation identities driven by their spatial location within the watershed. Five pathways of targeting the adoption of subsurface placement of phosphorus and buffer strips to HRUs within the watershed were assessed. Targeting pathways included targeting by HRU-level phosphorus losses, conservation identity of model operators, a hybrid approach combining HRU-level phosphorus losses and conservation identity of the model primary operator managing the HRU, and a proxy measure for random placement throughout the watershed. Targeting the placement of subsurface phosphorus application to all agricultural HRUs resulted in the greatest reduction in total phosphorus losses (32%) versus buffer strips (23%). For both conservation practices, targeting by HRU-level total phosphorus losses resulted in the most efficient rate of phosphorus reduction as measured by the ratio of phosphorus reduction to conservation practice adoption rates. The hybrid targeting approach closely resembled targeting by phosphorus losses, indicating near optimal results can be obtained even when constraining adoption by farmer characteristics. These results indicate that by developing management strategies based on a combination of field-level information and human-operator characteristics, a more efficient use of limited resources can be used while achieving near-maximal environmental benefits as compared to managing environmental outcomes solely based on field-level information.Two new bismuth(III) complexes, [BiL1Cl2] (1) and [BiL2Cl2] (2), in which L1 is (2-hydroxy-4-6-di-tert-butylbenzyl-2-pyridylmethyl)amine and L2 is 2,4-diiodo-6-((pyridine-2-ylmethylamino)methyl)phenol, were synthesized and characterized by elemental and conductivity analyses, atomic absorption spectrometry, infrared and 1H NMR spectroscopies. The molecular structure of 1 reveals that the NN’O ligand forms a 11 complex with bismuth through coordination via the nitrogen of the aliphatic amine, the nitrogen of the pyridine ring and the oxygen of the phenolate. The coordination sphere is completed with two chloride anions in a distorted square pyramidal geometry. Bismuth exhibits the same coordination mode in compound 2. The cytotoxic activity of 1 and 2 was investigated in a chronic myelogenous leukemia cell line. The complexes are approximately three times more potent than the corresponding free ligands, with the IC50 values 0.30 and 0.38 μM for complex 1 and 2, respectively. To address the cellular mechanisms underlying cell demise, apoptosis was quantified by flow cytometry analysis. From 0.1 μM, both complexes induce apoptosis and there is a remarkable concentration-dependent increase in the population of cells in apoptosis. The complexes were also evaluated against Gram-positive and Gram-negative bacteria. Both inhibited the bacterial growth in a concentration-dependent way, with remarkable activity in some of the tested strains, for example, complex 2 was more active than its free ligand against all bacterial strains and approximately fourteen times more potent against S. dysenteriae and S. typhimurium.

    This study aimed to evaluate the cost-effectiveness of community case management (CCM) program of childhood diarrhea by providing oral rehydration salts and zinc through community health workers in Burundi.

    A cost-effectiveness analysis study using a Markov modeling approach was undertaken to assess the CCM program of diarrhea from both provider and societal perspectives. GSK1838705A cost The CCM program was compared with the routine management of childhood diarrhea at health facilities. Primary data on the cost of childhood diarrhea management were collected. Both economic and health outcomes were assessed for a period of 5 years, and a discount rate of 3% was applied. One-way and probabilistic sensitivity analyses were performed.

    The CCM program was found to be both less costly and more effective resulting to a negative value of incremental cost-effectiveness ratios, indicating that the program was dominant producing cost savings. Compared with the routine treatment of diarrhea at health facilities, the CCM program would avert 2749 additional disability-adjusted life years over a period of 5 years.

Skip to toolbar