Nuclear waste Educator's workshop: What and how do we teach about nuclear waste?

A workshop was held at the Massachusetts Institute of Technology (MIT) on July 25th and 26th, 2022. The objective was to develop a blueprint for educating next-generation engineers and scientists about nuclear waste management and disposal, which requires knowledge from diverse disciplines, including nuclear, chemical, civil, environmental, and geological science and engineering. The 49 participants included university professors, researchers, industry experts, and government officials from different areas. First, we have developed a list of key fundamental knowledge on waste management and disposal across the nuclear fuel cycle. In addition, we discussed strategies on how to teach students with diverse backgrounds through innovative teaching strategies as well as how to attract students into this area. Through the workshop, we identified the critical needs to (1) develop community resources for nuclear waste education; (2) synthesize historical perspectives, including past contamination and the management of general hazardous waste; (3) emphasize a complete life-cycle perspective, including proper waste management as the key component for energy sustainability; (4) teach students how to communicate about the key facts and risks to technical and non-technical audiences; and (5) accelerate the use of the state-of-art-technologies to attract and retain a young workforce. Furthermore, we aim to build a diverse, inclusive community that supports students in developing their own narratives about nuclear waste, particularly in recognizing that antagonistic views have been important to improving safety and protecting public health and the environment.

Techno-Economic and life cycle assessment of standalone Single-Stream material recovery facilities in the United states.

Material Recovery Facilities (MRFs) are crucial players in achieving a circular economy. MRFs receive complex waste streams and separate valuable recyclables from these mixtures. This study conducts techno-economic analysis (TEA) to estimate the net present value (NPV) and life cycle assessment (LCA) to estimate different environmental impacts of a commercial scale standalone, single-stream MRF to assess the economic feasibility and environmental impacts of recovering valuable recyclables from an MRF processing 120,000 tonnes per year (t/y). The TEA employs a discounted cash flow rate of return (DCFROR) analysis over a 20-year facility lifetime, along with a sensitivity analysis on the impact of different operating and economic parameters. Results show that the total fixed cost of building the MRF facility is $23 MM, and the operating cost is $45.48/tonne. The NPV of the MRF can vary from $3.57 MM to $60 MM, while 100-year global warming potential can range from 5.98 to 8.53 kg carbon dioxide equivalents (CO2-eq) per tonne of MSW. We have also found that MSW composition (arising from regional effects) significantly impacts costs, 100-year global warming potential, and other impact categories such as acidification potential, eutrophication potential, ecotoxicity, ozone depletion, photochemical oxidation, carcinogenic effects, and non-carcinogenic effects. Sensitivity and uncertainty analysis indicate that waste composition and market prices significantly impact the profitability of the MRF, and the waste composition mostly impacts global warming potential. Our analysis also indicates that facility capacity, fixed capital cost, and waste tipping fees are vital parameters that affect the economic viability of MRF operations.

Evolving radon diffusion through earthen barriers at uranium waste disposal sites.

Field measurements of Rn-222 fluxes from the tops and bottoms of compacted clay radon barriers were used to calculate effective Rn diffusion coefficients (DRn) at four uranium waste disposal sites in the western United States to assess cover performance after more than 20 years of service. Values of DRn ranged from 7.4 × 10-7 to 6.0 × 10-9 m2/s, averaging 1.42 × 10-7. Water saturation (SW) from soil cores indicated that there was relatively little control of DRn by SW, especially at higher moisture levels, in contrast to estimates from most steady-state diffusion models. This is attributed to preferential pathways intrinsic to construction of the barriers or to natural process that have developed over time including desiccation cracks, root channels, and insect burrows in the engineered earthen barriers. A modification to some models in which fast and slow pathway DRn values are partitioned appears to give a good representation of the data; 4% of the fast pathway was needed to fit the data regression. For locations with high Sw and highest DRn (and fluxes) at each site, the proportion of fast pathway ranged from 1.7% to 34%, but for many locations with lower fluxes, little if any fast pathway was needed.

Building the foundation for a community-generated national research blueprint for inherited bleeding disorders: research priorities to transform the care of people with hemophilia.

BACKGROUND: Decades of research have transformed hemophilia from severely limiting children's lives to a manageable disorder compatible with a full, active life, for many in high-income countries. The direction of future research will determine whether exciting developments truly advance health equity for all people with hemophilia (PWH). National Hemophilia Foundation (NHF) and American Thrombosis and Hemostasis Network conducted extensive inclusive all-stakeholder consultations to identify the priorities of people with inherited bleeding disorders and those who care for them. RESEARCH DESIGN AND METHODS: Working group (WG) 1 of the NHF State of the Science Research Summit distilled the community-identified priorities for hemophilia A and B into concrete research questions and scored their feasibility, impact, and risk. RESULTS: WG1 defined 63 top priority research questions concerning arthropathy/pain/bone health, inhibitors, diagnostics, gene therapy, the pediatric to adult transition of care, disparities faced by the community, and cardiovascular disease. This research has the potential to empower PWH to thrive despite lifelong comorbidities and achieve new standards of wellbeing, including psychosocial. CONCLUSIONS: Collaborative research and care delivery will be key to capitalizing on current and horizon treatments and harnessing technical advances to improve diagnostics and testing, to advance health equity for all PWH.

Hemophilia is the best known of the inherited bleeding disorders (BD). This is a rare condition that causes disproportionate bleeding, often into joints and vital organs. Factor replacement, injecting recombinant or plasma-based clotting factor products directly into the vein, became commonplace to control the disorder in the 1990s and 2000s. Prophylaxis, or injecting replacement factor every few days into people with hemophilia (PWH), has revolutionized patients' lives. In the last few years, other advances in new therapies have entered this space, such as non-factor replacement therapies and gene therapy. With many more research advances on the horizon, the National Hemophilia Foundation (NHF) initiated a State of the Science Research Summit in 2020. This event was attended by over 880 interested parties to help design an agenda of research priorities for inherited BDs for the next decade, based on community consultations. NHF formed multiple Working Groups (WG), each exploring a theme resulting from the community consultations, and presenting their results at the Summit. Led by 2 hematologists who manage and treat PWH daily, the 21-community member WG1 assigned to hemophilia A and B divided into 7 subgroups to identify and organize research priorities for different topic areas. The outcomes focused on prioritizing patients' needs, technological advances, and research in the areas of greatest potential for PWH and those who care for them. The results are a roadmap for the future execution of a research plan that truly serves the community.

Efanesoctocog alfa for hemophilia A: results from a phase 1 repeat-dose study.

Efanesoctocog alfa (rFVIIIFc-VWF-XTEN; BIVV001) is a new class of factor VIII (FVIII) replacement that breaks the von Willebrand factor-imposed FVIII half-life ceiling. In a phase 1/2a study, single-dose efanesoctocog alfa was well tolerated, and no safety concerns were identified. We evaluated the safety, tolerability, and pharmacokinetics of repeat-dose efanesoctocog alfa in a phase 1 study in previously treated adults (≥150 exposure days) with severe hemophilia A. Participants received 4 once weekly doses of efanesoctocog alfa (cohort 1, 50 IU/kg; cohort 2, 65 IU/kg). All enrolled participants (cohort 1, n = 10; cohort 2, n = 14) completed the study. Inhibitor development to FVIII was not detected. After the last dose of efanesoctocog alfa, geometric mean (range) FVIII activity half-life, area under the activity-time curve, and steady-state maximum concentration for cohort 1 and cohort 2 were 41.3 (34.2-50.1) and 37.3 (28.9-43.8) hours, 8290 (5810-10 300) and 11 200 (7040-15 800) hours × IU/dL, and 131 (96-191) and 171 (118-211) IU/dL, respectively. There was minimal accumulation after 4 doses. Mean FVIII activity for cohort 1 and cohort 2, respectively, was 46% and 69% on day 3 postdose and 10% and 12% on day 7 postdose. Overall, 4 once-weekly doses of efanesoctocog alfa were well tolerated, no safety concerns were identified, and no bleeds were reported during the treatment period. Once-weekly efanesoctocog alfa provided high sustained FVIII activity within the normal to near-normal range for 3 to 4 days postdose and may improve protection against bleeds in patients with hemophilia A. The trial is study 2018-001535-51 in the EU Clinical Trials Register.

Radon fluxes at four uranium mill tailings disposal sites after about 20 years of service.

To evaluate the properties of earthen covers over uranium mill tailings disposal cells after about 20 years of service, we measured Rn-222 fluxes and radon barrier properties at the Falls City, TX, Bluewater, NM, Shirley Basin South, WY, and Lakeview, OR disposal sites in western USA. A total of 115 in-service Rn fluxes were obtained at 26 test pit locations from the top surface of the exposed Rn barrier (i.e., after protective layers were removed by excavation) and 24 measurements were obtained from the surface of the underlying waste after excavation through the Rn barrier layer. Rn-222 concentrations were determined in accumulation chambers using a continuously monitoring electronic radon monitor (ERM) equipped with a solid-state alpha particle detector. Effects of surface features on Rn flux including vegetation, seasonal ponding, and animal burrowing were quantified. Comparison of measured fluxes with values that were measured shortly after the Rn barriers were completed (as-built) show that most measurements fell within the range of the as-built fluxes, generally at very low fluxes. At two sites fluxes were measured that were greater than the highest as-built flux. High fluxes are typically caused by a combination of enhanced moisture removal and preferential pathways for Rn transport, often caused by deep-rooted plants. Such localized features result in a spatially heterogeneous distribution of fluxes that can vary substantially over only a meter or two.

Mechanisms of Congenital Heart Disease Caused by NAA15 Haploinsufficiency.

[Figure: see text].

Targeting of antithrombin in hemophilia A or B with investigational siRNA therapeutic fitusiran-Results of the phase 1 inhibitor cohort.

BACKGROUND: Fitusiran, an investigational small interfering RNA therapy, reduces antithrombin production to rebalance hemostasis in people with hemophilia A or B, with or without inhibitors. OBJECTIVES: To evaluate the safety and efficacy of fitusiran treatment for people with moderate/severe hemophilia A or B with inhibitors. PATIENTS/METHODS: In this open-label phase 1, part D study, 17 males with hemophilia A or B with inhibitors received three once-monthly subcutaneous injections of fitusiran 50 mg (n = 6) or 80 mg (n = 11); followed for up to 112 days. Endpoints included safety (primary), pharmacokinetics/pharmacodynamics (secondary), annualized bleeding rate, and patient-reported outcomes (exploratory). RESULTS: The most common adverse event was injection site erythema (n = 8). No thrombotic events were reported. At nadir, mean (standard error of the mean [SEM]) antithrombin activity decreased from baseline by 82.0% (2.2) and 87.4% (0.7) in the 50 mg and 80 mg groups, respectively. Antithrombin reduction was associated with increased thrombin generation. 11/17 (64.7%) participants had no bleeds during the observation period (mean [standard deviation] 69.4 [16.3] days). Mean (SEM) changes from baseline in Haemophilia Quality of Life Questionnaire for Adults total (-9.2 [2.9]) and physical health (-12.3 [3.9]) domain scores suggested clinically meaningful improvement. CONCLUSIONS: Monthly fitusiran was generally well tolerated, lowered antithrombin levels from baseline, and resulted in improved thrombin generation. These preliminary results suggest that monthly fitusiran treatment may reduce bleeding episodes and improve quality of life in participants with hemophilia A or B with inhibitors.

BIVV001 Fusion Protein as Factor VIII Replacement Therapy for Hemophilia A.

BACKGROUND: Factor VIII replacement products have improved the care of patients with hemophilia A, but the short half-life of these products affects the patients' quality of life. The half-life of recombinant factor VIII ranges from 15 to 19 hours because of the von Willebrand factor chaperone effect. BIVV001 (rFVIIIFc-VWF-XTEN) is a novel fusion protein designed to overcome this half-life ceiling and maintain high sustained factor VIII activity levels. Data are lacking on the safety and pharmacokinetics of single-dose BIVV001. METHODS: In this phase 1-2a open-label trial, we consecutively assigned 16 previously treated men (18 to 65 years of age) with severe hemophilia A (factor VIII activity, <1%) to receive a single intravenous injection of recombinant factor VIII at a dose of 25 IU per kilogram of body weight (lower-dose group) or 65 IU per kilogram (higher-dose group). This injection was followed by a washout period of at least 3 days. The patients then received a single intravenous injection of BIVV001 at the same corresponding dose of either 25 IU or 65 IU per kilogram. Adverse events and pharmacokinetic measurements were assessed. RESULTS: No inhibitors to factor VIII were detected and no hypersensitivity or anaphylaxis events were reported up to 28 days after the injection of single-dose BIVV001. The geometric mean half-life of BIVV001 was three to four times as long as that of recombinant factor VIII (37.6 hours vs. 9.1 hours in the lower-dose group and 42.5 vs. 13.2 hours in the higher-dose group); the area under the curve (AUC) for product exposure was six to seven times as great in the two dose groups (4470 hours vs. 638 hours × IU per deciliter in the lower-dose group and 12,800 hours vs. 1960 hours × IU per deciliter in the higher-dose group). After the injection of BIVV001 in the higher-dose group, the mean factor VIII level was in the normal range (≥51%) for 4 days and 17% at day 7, which suggested the possibility of a weekly interval between treatments. CONCLUSIONS: In a small, early-phase study involving men with severe hemophilia A, a single intravenous injection of BIVV001 resulted in high sustained factor VIII activity levels, with a half-life that was up to four times the half-life associated with recombinant factor VIII, an increase that could signal a new class of factor VIII replacement therapy with a weekly treatment interval. No safety concerns were reported during the 28-day period after administration. (Funded by Sanofi and Sobi; ClinicalTrials.gov number, NCT03205163.).

Hydraulic and mechanical behavior of municipal solid waste and high-moisture waste mixtures.

The objective of this study was to investigate how addition of high-moisture waste (HMW) affects the hydraulic and mechanical behavior of municipal solid waste (MSW). Direct shear and hydraulic conductivity tests were conducted on MSW, HMW, and MSW-HMW mixtures prepared with HMW contents ranging from 20% to 80% (by total mass). Direct shear tests were conducted at normal stress between 22 and 168 kPa and hydraulic conductivity tests were conducted at vertical effective stresses of approximately 50, 100, and 200 kPa. A threshold HMW content of 40% was identified corresponding to substantial change in friction angle and hydraulic conductivity of the mixtures. Municipal solid waste and MSW-HMW mixtures with less than 40% HMW had friction angles between 29° and 32° and hydraulic conductivities greater than or equal to 1.3 × 10-6 m/s. At HMW contents above 40%, the friction angle and hydraulic conductivity decreased with increasing HMW content. At 80% HMW, the hydraulic and mechanical behavior of the MSW-HMW mixture was comparable to HMW. The HMW had a friction angle of approximately 2° and hydraulic conductivity of 1.1 × 10-11 m/s at a vertical effective stress of 50 kPa. Additional direct shear tests conducted on MSW and MSW-HMW mixtures soaked in water to simulate subsequent wetting post disposal revealed a decrease in friction angle from approximately 29° to 24° for MSW mixed with 40% HMW.

The impact of pressure, moisture and temperature on pyrolysis of municipal solid waste under simulated landfill conditions and relevance to the field data from elevated temperature landfill.

Experiments were conducted with simulated Municipal Solid Waste (MSW) to understand the impact of pressure, moisture, and temperature on MSW decomposition under simulated landfill conditions. Three experimental phases were completed, where the first two phases provided baseline results and assisted in fine tuning parameters such as pressure, temperature, gas composition, and moisture content for phase three. The manuscript focuses on the results from third phase. In the third phase, the composition of the gases evolved from representative MSW samples was tested over time in two pressure conditions, 101 kilopascals (kPa) (atmospheric pressure) and 483 kPa, with varying moisture contents (38 to 55 wt%) and controlled temperatures (50 to 200 °C) in the presence of biological inhibitors. The headspace in the reactor in phase three was pressurized with gas mixture of 50/50 (vol%) of methane (CH4) and carbon dioxide (CO2) setting the initial CH4/CO2 gas composition ratio to 1.0 at time t = 0 days. The results established moisture ranges that affect hydrogen (H2) production and the CH4/CO2 ratio at different temperature and pressure conditions. Results show that at 85 °C, there was a change in the CH4/CO2 ratio from 1.0 to 0.3. Additionally, moisture contents from 47 to 43.5 wt% caused the CH4/CO2 ratio to increase from 1.0 to 1.2, yet from 43.5 to 38 wt%, the ratio reversed and declined to 0.3, returning to 1.0 for moisture levels below 38 wt%. Thus, moisture levels above 47 wt% and below 38 wt%, for the system tested, allow thermal reactions to proceed without a measured change in CH4/CO2 ratio. H2 generation rates follow a similar trend with moisture, yet definitively increase with increased pressure from 101 kPa to 483 kPa. The observed change in solid MSW and gas composition under controlled pressure, moisture, and temperature suggests the presence of thermal reactions in the absence of oxygen.

Small-Molecule Screen Identifies De Novo Nucleotide Synthesis as a Vulnerability of Cells Lacking SIRT3.

Sirtuin 3 (SIRT3) is a NAD+-dependent deacetylase downregulated in aging and age-associated diseases such as cancer and neurodegeneration and in high-fat diet (HFD)-induced metabolic disorders. Here, we performed a small-molecule screen and identified an unexpected metabolic vulnerability associated with SIRT3 loss. Azaserine, a glutamine analog, was the top compound that inhibited growth and proliferation of cells lacking SIRT3. Using stable isotope tracing of glutamine, we observed its increased incorporation into de novo nucleotide synthesis in SIRT3 knockout (KO) cells. Furthermore, we found that SIRT3 KO cells upregulated the diversion of glutamine into de novo nucleotide synthesis through hyperactive mTORC1 signaling. Overexpression of SIRT3 suppressed mTORC1 and growth in vivo in a xenograft tumor model of breast cancer. Thus, we have uncovered a metabolic vulnerability of cells with SIRT3 loss by using an unbiased small-molecule screen.

Heat Generation and Accumulation in Municipal Solid Waste Landfills.

There have been reports of North American landfills that are experiencing temperatures in excess of 80-100 °C. However, the processes causing elevated temperatures are not well understood. The objectives of this study were to develop a model to describe the generation, consumption and release of heat from landfills, to predict landfill temperatures, and to understand the relative importance of factors that contribute to heat generation and accumulation. Modeled heat sources include energy from aerobic and anaerobic biodegradation, anaerobic metal corrosion, ash hydration and carbonation, and acid-base neutralization. Heat removal processes include landfill gas convection, infiltration, leachate collection, and evaporation. The landfill was treated as a perfectly mixed batch reactor. Model predictions indicate that both anaerobic metal corrosion and ash hydration/carbonation contribute to landfill temperatures above those estimated from biological reactions alone. Exothermic pyrolysis of refuse, which is hypothesized to be initiated due to a local accumulation of heat, was modeled empirically to illustrate its potential impact on heat generation.

Evaluation of Soil Manipulation to Prepare Engineered Earthen Waste Covers for Revegetation.

Seven ripping treatments designed to improve soil physical conditions for revegetation were compared on a test pad simulating an earthen cover for a waste disposal cell. The field test was part of study of methods to convert compacted-soil waste covers into evapotranspiration covers. The test pad consisted of a compacted layer of fine-textured soil simulating a barrier protection layer overlain by a gravelly sand bedding layer and a cobble armor layer. Treatments included combinations of soil-ripping implements (conventional shank [CS], wing-tipped shank [WTS], and parabolic oscillating shank with wings [POS]), ripping depths, and number of passes. Dimensions, dry density, moisture content, and particle size distribution of disturbance zones were determined in two trenches excavated across rip rows. The goal was to create a root-zone dry density between 1.2 and 1.6 Mg m and a seedbed soil texture ranging from clay loam to sandy loam with low rock content. All treatments created V-shaped disturbance zones as measured on trench faces. Disturbance zone size was most influenced by ripping depth. Winged implements created larger disturbance zones. All treatments lifted fines into the bedding layer, moved gravel and cobble down into the fine-textured protection layer, and thereby disrupted the capillary barrier at the interface. Changes in dry density within disturbance zones were comparable for the CS and WTS treatments but were highly variable among POS treatments. Water content increased in the bedding layer and decreased in the protection layer after ripping. The POS at 1.2-m depth and two passes created the largest zone with a low dry density (1.24 Mg m) and the most favorable seedbed soil texture (gravely silt loam). However, ripping also created large soil aggregates and voids in the protection layer that may produce preferential flow paths and reduce water storage capacity.

Alternative Splicing Signatures in RNA-seq Data: Percent Spliced in (PSI).

Thousands of alternative exons are spliced out of messenger RNA to increase protein diversity. High-throughput sequencing of short cDNA fragments (RNA-seq) generates a genome-wide snapshot of these post-transcriptional processes. RNA-seq reads yield insights into the regulation of alternative splicing by revealing the usage of known or unknown splice sites as well as the expression level of exons. Constitutive exons are never covered by split alignments, whereas alternative exonic parts are located within highly expressed splicing junctions. The ratio between reads including or excluding exons, also known as percent spliced in index (PSI), indicates how efficiently sequences of interest are spliced into transcripts. This protocol describes a method to calculate the PSI without prior knowledge of splicing patterns. It provides a quantitative, global assessment of exon usage that can be integrated with other tools that identify differential isoform processing. Novel, complex splicing events along a genetic locus can be visualized in an exon-centric manner and compared across conditions.

HEART DISEASE. Titin mutations in iPS cells define sarcomere insufficiency as a cause of dilated cardiomyopathy.

Human mutations that truncate the massive sarcomere protein titin [TTN-truncating variants (TTNtvs)] are the most common genetic cause for dilated cardiomyopathy (DCM), a major cause of heart failure and premature death. Here we show that cardiac microtissues engineered from human induced pluripotent stem (iPS) cells are a powerful system for evaluating the pathogenicity of titin gene variants. We found that certain missense mutations, like TTNtvs, diminish contractile performance and are pathogenic. By combining functional analyses with RNA sequencing, we explain why truncations in the A-band domain of TTN cause DCM, whereas truncations in the I band are better tolerated. Finally, we demonstrate that mutant titin protein in iPS cell-derived cardiomyocytes results in sarcomere insufficiency, impaired responses to mechanical and ß-adrenergic stress, and attenuated growth factor and cell signaling activation. Our findings indicate that titin mutations cause DCM by disrupting critical linkages between sarcomerogenesis and adaptive remodeling.

Smooth Muscle Cell Genome Browser: Enabling the Identification of Novel Serum Response Factor Target Genes.

Genome-scale expression data on the absolute numbers of gene isoforms offers essential clues in cellular functions and biological processes. Smooth muscle cells (SMCs) perform a unique contractile function through expression of specific genes controlled by serum response factor (SRF), a transcription factor that binds to DNA sites known as the CArG boxes. To identify SRF-regulated genes specifically expressed in SMCs, we isolated SMC populations from mouse small intestine and colon, obtained their transcriptomes, and constructed an interactive SMC genome and CArGome browser. To our knowledge, this is the first online resource that provides a comprehensive library of all genetic transcripts expressed in primary SMCs. The browser also serves as the first genome-wide map of SRF binding sites. The browser analysis revealed novel SMC-specific transcriptional variants and SRF target genes, which provided new and unique insights into the cellular and biological functions of the cells in gastrointestinal (GI) physiology. The SRF target genes in SMCs, which were discovered in silico, were confirmed by proteomic analysis of SMC-specific Srf knockout mice. Our genome browser offers a new perspective into the alternative expression of genes in the context of SRF binding sites in SMCs and provides a valuable reference for future functional studies.

Leaching characteristics of toxic constituents from coal fly ash mixed soils under the influence of pH.

Leaching behaviors of Arsenic (As), Barium (Ba), Calcium (Ca), Cadmium (Cd), Magnesium (Mg), Selenium (Se), and Strontium (Sr) from soil alone, coal fly ash alone, and soil-coal fly ash mixtures, were studied at a pH range of 2-14 via pH-dependent leaching tests. Seven different types of soils and coal fly ashes were tested. Results of this study indicated that Ca, Cd, Mg, and Sr showed cationic leaching pattern while As and Se generally follows an oxyanionic leaching pattern. On the other hand, leaching of Ba presented amphoteric-like leaching pattern but less pH-dependent. In spite of different types and composition of soil and coal fly ash investigated, the study reveals the similarity in leaching behavior as a function of pH for a given element from soil, coal fly ash, and soil-coal fly ash mixtures. The similarity is most likely due to similar controlling mechanisms (e.g., solubility, sorption, and solid-solution formation) and similar controlling factors (e.g., leachate pH and redox conditions). This offers the opportunity to transfer knowledge of coal fly ash that has been extensively characterized and studied to soil stabilized with coal fly ash. It is speculated that unburned carbon in off-specification coal fly ashes may provide sorption sites for Cd resulting in a reduction in concentration of these elements in leachate from soil-coal fly ash mixture. Class C fly ash provides sufficient CaO to initiate the pozzolanic reaction yielding hydrated cement products that oxyanions, including As and Se, can be incorporated into.