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In a field experiment at Vandenberg Air Force Base (VAFB) designed to mimic the impact of a small-volume release of E10 (10% ethanol and 90% conventional gasoline), two plumes were created by injecting extracted groundwater spiked with benzene, toluene, and o-xylene, abbreviated BToX (No-Ethanol Lane) and BToX plus ethanol (With-Ethanol Lane) for 283 days. We developed a reactive transport model to understand processes controlling the fate of ethanol and BToX. The model was calibrated to the extensive field dataset and accounted for concentrations of sulfate, iron, acetate, and methane along with iron-reducing bacteria, sulfate-reducing bacteria, fermentative bacteria, and methanogenic archaea. The benzene plume was about 4.5 times longer in the With-Ethanol Lane than in the No-Ethanol Lane. Matching this different behavior in the two lanes required inhibiting benzene degradation in the presence of ethanol. Inclusion of iron reduction with negligible growth of iron-reducers was required to reproduce the observed constant degradation rate of benzene. Modeling suggested that vertical dispersion and diffusion of sulfate from an adjacent aquitard were important sources of sulfate in the aquifer. Matching of methane data required incorporating initial fermentation of ethanol to acetate, methane loss by outgassing, and methane oxidation coupled to sulfate and iron reduction. Simulation of microbial growth using dual Monod kinetics, and including inhibition by more favorable electron acceptors, generally resulted in reasonable yields for microbial growth of 0.01-0.05.

Extracellular vesicle (EV)-carried miRNAs can influence gene expression and functional phenotypes in recipient cells. Argonaute 2 (Ago2) is a key miRNA-binding protein that has been identified in EVs and could influence RNA silencing. However, Ago2 is in a non-vesicular form in serum and can be an EV contaminant. In addition, RNA-binding proteins (RBPs), including Ago2, and RNAs are often minor EV components whose sorting into EVs may be regulated by cell signaling state. To determine the conditions that influence detection of RBPs and RNAs in EVs, we evaluated the effect of growth factors, oncogene signaling, serum, and cell density on the vesicular and nonvesicular content of Ago2, other RBPs, and RNA in small EV (SEV) preparations. Media components affected both the intravesicular and extravesicular levels of RBPs andmiRNAs in EVs,with serumcontributing strongly to extravesicular miRNA contamination. Furthermore, isolation of EVs from hollow fiber bioreactors revealed complex preparations, with multiple EV-containing peaks and a large amount of extravesicular Ago2/RBPs. Finally, KRAS mutation impacts the detection of intra- and extra-vesicular Ago2. These data indicate that multiple cell culture conditions and cell states impact the presence of RBPs in EV preparations, some of which can be attributed to serumcontamination. [ABSTRACT FROM AUTHOR]

Natural infection as well as vaccination with live or attenuated viruses elicit tissue resident, CD8+ memory T cell (Trm) response. Trm cells so elicited act quickly upon reencounter with the priming agent to protect the host. These Trm cells express a unique molecular signature driven by the master regulators—Runx3 and Hobit. We previously reported that intranasal instillation of a subunit vaccine in a prime boost vaccination regimen installed quick-acting, CD8+ Trm cells in the lungs that protected against lethal vaccinia virus challenge. It remains unexplored whether CD8+ Trm responses so elicited are driven by a similar molecular signature as those elicited by microbes in a real infection or by live, attenuated pathogens in conventional vaccination. We found that distinct molecular signatures distinguished subunit vaccine-elicited lung interstitial CD8+ Trm cells from subunit vaccine-elicited CD8+ effector memory and splenic memory T cells. Nonetheless, the transcriptome signature of subunit vaccine elicited CD8+ Trm resembled those elicited by virus infection or vaccination. Clues to the basis of tissue residence and function of vaccine specific CD8+ Trm cells were found in transcripts that code for chemokines and chemokine receptors, purinergic receptors, and adhesins when compared to CD8+ effector and splenic memory T cells. Our findings inform the utility of protein-based subunit vaccination for installing CD8+ Trm cells in the lungs to protect against respiratory infectious diseases that plague humankind. [ABSTRACT FROM AUTHOR]

The relationship between concept mapping and comprehension was investigated in conjunction with science instructional laboratories. Measured were student skills and aptitudes applying aptitude treatment interaction procedures to investigate interactions between a concept mapping treatment and student aptitudes. (KR)

Described and assessed was the teacher's role in three elementary school science programs which included hands-on learning experiences for the students. Results indicated that this role varied with the manner in which hands-on materials were used in the program. (CW)

A series of quantitative decision frameworks were developed to aid in the evaluation of Monitored Natural Attenuation (MNA) as a remedy for 1,4‐dioxane, chlorinated ethanes, and chlorinated ethenes. The end product is an updated version of BioPIC, a successful, existing decision framework for MNA of chlorinated ethenes. In evaluating MNA, the goal is to follow existing protocols but also incorporate more recent insights that have increased the potential viability of this technology for a wider number of contaminants. This includes data supporting the first line of evidence for MNA (decreasing concentration trends over time at appropriate sampling locations), as well as data that will serve as secondary and tertiary lines of evidence for MNA. For the BioPIC update, a similar lines of evidence approach was developed, using information from literature and project‐specific data to identify the relevant lines of evidence. As part of the update, a model for predicting contaminant trends over time and distance, including a method to estimate site‐specific biodegradation rate constants for chlorinated ethenes, chlorinated ethanes, and 1,4‐dioxane, has been included within BioPIC. The quantitative software tool provides step‐by‐step technical guidance for collecting and evaluating other lines of evidence, including data associated with targeted 14C assays, isotope fractionation, biomarkers for degradation, geochemical parameters, and co‐contaminant concentrations, to improve the MNA evaluation process. Article Impact Statement: This paper describes a new technical framework to help evaluate monitored natural attenuation as a remedy for an expanded set of compounds. [ABSTRACT FROM AUTHOR]

With the clinical approval of T-cell-dependent immune checkpoint inhibitors for many cancers, therapeutic cancer vaccines have re-emerged as a promising immunotherapy. Cancer vaccines require the addition of immunostimulatory adjuvants to increase vaccine immunogenicity, and increasingly multiple adjuvants are used in combination to bolster further and shape cellular immunity to tumor antigens. However, rigorous quantification of adjuvants' synergistic interactions is challenging due to partial redundancy in costimulatory molecules and cytokine production, leading to the common assumption that combining both adjuvants at the maximum tolerated dose results in optimal efficacy. Herein, we examine this maximum dose assumption and find combinations of these doses are suboptimal. Instead, we optimized dendritic cell activation by extending the Multidimensional Synergy of Combinations (MuSyC) framework that measures the synergy of efficacy and potency between two vaccine adjuvants. Initially, we performed a preliminary in vitro screening of clinically translatable adjuvant receptor targets (TLR, STING, NLL, and RIG-I). We determined that STING agonist (CDN) plus TLR4 agonist (MPL-A) or TLR7/8 agonist (R848) as the best pairwise combinations for dendritic cell activation. In addition, we found that the combination of R848 and CDN is synergistically efficacious and potent in activating both murine and human antigen-presenting cells (APCs) in vitro. These two selected adjuvants were then used to estimate a MuSyC-dose optimized for in vivo T-cell priming using ovalbumin-based peptide vaccines. Finally, using B16 melanoma and MOC1 head and neck cancer models, MuSyC-dose-based adjuvating of cancer vaccines improved the antitumor response, increased tumor-infiltrating lymphocytes, and induced novel myeloid tumor infiltration changes. Further, the MuSyC-dose-based adjuvants approach did not cause additional weight changes or increased plasma cytokine levels compared to CDN alone. Collectively, our findings offer a proof of principle that our MuSyC-extended approach can be used to optimize cancer vaccine formulations for immunotherapy. [ABSTRACT FROM AUTHOR]

Passive reactive barriers (PRBs) are commonly used to treat groundwater that is contaminated with chlorinated solvents such as trichloroethylene (TCE). A number of PRBs have been constructed with plant mulch as the reactive medium. The TCE is removed in these barriers through adsorption, biological reductive dechlorination, and abiotic reactions with reduced iron minerals that are formed in the barrier. Generally speaking, adsorption has limited capacity for TCE removal and abiotic dechlorination is dependent on metal sulfides of biogenic origin. Therefore, the long-term performance of these barriers will be controlled by their capacity to support biological activity. Laboratory batch experiments were inoculated with an enrichment culture of dechlorinating microorganisms. Dechlorination of TCE to ethylene was achieved using plant mulch; however, neither water extractable nor organic-solvent extractable components of the mulch could sustain dechlorination of TCE. This indicates that biodegradation of organic wood fibers in the plant cell wall provides electron donors for dechlorination of TCE. Kinetic analysis of the methane production in the batch tests provides supporting evidence that the plant mulch is able to sustain long-term biological activity in a typical harrier constructed with plant tissues. The recognition of the intact plant tissues as a long-term electron donor expands the knowledge about the microbial dechlorination under natural conditions. In addition, the production of dissolved inorganic carbon (DIC) observed in a column study was used to estimate the life cycle of a full-scale biowall installed at Altus AFB, Oklahoma. Based on a consistent downward trend in DIC concentrations in the effluent and a stable concentration in the influent over time, the mulch in the biowall is expected to support microbial activity for 10 years. DOI: 10.1061/(ASCE)EE.1943-7870.0000253 CE Database subject headings: Barriers; Chloride; Groundwater management; TCE. Author keywords: Reactive barrier; Biowall; Dechlorination of TCE; Biodegradation of chlorinated solvents; Groundwater; Plant mulch.

Several regulatory agencies recommend screening petroleum vapor intrusion (PVI) sites based on vertical screening distance between a petroleum hydrocarbon source in soil or groundwater and a building foundation. U.S. Environmental Protection Agency (U.S. EPA) indicate the risk of PVI is minimal at buildings that are separated by more than 6 feet (1.8 m) from a dissolved‐phase source and 15 feet (4.6 m) from a light nonaqueous phase liquid (LNAPL) source. This vertical screening distance method is not, however, recommended at sites with leaded gasoline sources containing ethylene dibromide (EDB) because of a lack of field data to document EDB attenuation in the vadose zone. To help address this gap, depth‐discrete soil‐gas samples were collected at a leaded gasoline release site in Sobieski, Minnesota (USA). The maximum concentration of EDB in groundwater (175 μg/L) at the site was high relative to those observed at other leaded gasoline release sites. Soil gas was analyzed for EDB using a modification of U.S. EPA Method TO‐14A that achieved analytical detection limits below the U.S. EPA Vapor Intrusion Screening Level (VISL) for EDB based on a 10−6 cancer risk (<0.16 μg/m3). Concentrations of EDB in soil gas above LNAPL reached as high as 960 μg/m3 and decreased below the VISL within a source‐separation distance of 7 feet. This result coupled with BioVapor model predictions of EDB concentrations indicate that vertical screening distances recommended by regulatory agencies at PVI sites are generally applicable for EDB over the range of anticipated source concentrations and soil types at most sites. [ABSTRACT FROM AUTHOR]

The natural life cycle of a plume of methyl tert-butyl ether from a spill of gasoline is controlled by the rate of attenuation of the source (due to partitioning from the residual gasoline to the flow of groundwater) and the rate of attenuation in the plume (due to dispersion and natural biodegradation). Rates of attenuation were extracted for plumes in California, Florida, North Carolina, New York, and New Jersey. The maximum rate of attenuation of the source was 0.75 per year. The rates of attenuation in the plumes varied from 0.56 to 4.3 per year. In all cases, the rate of attenuation of the plume exceeded the rate of attenuation of the source. As these plumes progress through their life cycle, they should recede back toward their source. CE Database keywords: Ground water; Attenuation; Plumes; Gasoline.