Assessing the Impact of Wildfire Smoke Transport Through Chemical Transport Modeling, Satellite Retrievals, and Ground-Based Observations of Ozone in Rural Nevada.

Wildfires emit a large amount of ozone precursors, nitrogen oxides, and particulate matter into the troposphere and sometimes the stratosphere. With the increasing wildfire events in recent years, the western U.S.

The composition of branched-chain amino acids modulates response to nucleotide supplementation of low-protein diets in nursery pigs.

A total of 160 pigs (initial body weight [BW], 5.79 ± 0.01 kg) were used to investigate the effects of dietary nucleotides and branched-chain amino acids (BCAA) supplementation of low-protein diets on growth performance, blood metabolites, short-chain fatty acids (SCFA), apparent ileal and total tract digestibility of nutrients (AID and ATTD).

Potential Errors in CMAQ NO:NO Ratios and Upper Tropospheric NO Impacting the Interpretation of TROPOMI Retrievals.

Although Chemical Transport Models (CTMs) such as the Community Multiscale Air Quality Model (CMAQ) have been used in linking observations of trace gases to emissions and developing vertical column distributions, there remain consistent biases between CTM simulations and satellite retrievals. Simulated tropospheric NO vertical column densities (VCDs) are generally higher over areas with large NO sources when compared with retrievals, while an opposite bias is found over low NO regions. Artificial (i.

Analyzing the Role of Chemical Mechanism Choice in Wintertime PM Modeling for Temperature Inversion-Prone Areas.

Chemical transport models are used for federal compliance demonstrations when areas are out of attainment, but there is no guidance for choosing a chemical mechanism. With the 2024 change of the annual PM standard and the prevalence of multiday wintertime inversion episodes in the western U.S.

Responses in weanling pigs fed low protein diets supplemented with dietary nucleotides.

Evidence suggests that nucleotide supplementation in diets improves intestinal development, immune function, and cell growth. Stressful events such as weaning in pigs may increase nucleotide demand, making exogenous supplementation potentially beneficial. This study evaluated the effects of low-protein () diets supplemented with dietary nucleotides on growth performance, postweaning diarrhea (), nutrient digestibility, and blood metabolites.

Assessment of Airport-Related Emissions and Their Impact on Air Quality in Atlanta, GA, Using CMAQ and TROPOMI.

Impacts of emissions from the Atlanta Hartsfield-Jackson Airport (ATL) on ozone (O), ultrafine particulates (UFPs), and fine particulate matter (PM) are evaluated using the Community Multiscale Air Quality (CMAQ) model and high-resolution satellite observations of NO vertical column densities (VCDs) from TROPOMI. Two airport inventories are compared: an inventory using emissions where landing and take-off (LTO) processes are allocated to the surface (default) and a modified (3D) inventory that has LTO and cruise emissions vertically and horizontally distributed, accounting for aircraft climb and descend rates. The 3D scenario showed reduced bias and error between CMAQ and TROPOMI VCDs compared to the default scenario [i.

Demographic Inequities in Health Outcomes and Air Pollution Exposure in the Atlanta Area and its Relationship to Urban Infrastructure.

Environmental burdens such as air pollution are inequitably distributed with groups of lower socioeconomic statuses, which tend to comprise of large proportions of racial minorities, typically bearing greater exposure. Such groups have also been shown to present more severe health outcomes which can be related to adverse pollution exposure. Air pollution exposure, especially in urban areas, is usually impacted by the built environment, such as major roadways, which can be a significant source of air pollution.

Linked Response of Aerosol Acidity and Ammonia to SO and NO Emissions Reductions in the United States.

Large reductions of sulfur and nitrogen oxide emissions in the United States have led to considerable improvements in air quality, though recent analyses in the Southeastern United States have shown little response of aerosol pH to these reductions. This study examines the effects of reduced emissions on the trend of aerosol acidity in fine particulate matter (PM), at a nationwide scale, using ambient concentration data from three monitoring networks-the Ammonia Monitoring Network (AMoN), the Clean Air Status and Trends network (CASTNET) and the Southeastern Aerosol Research and Characterization Network (SEARCH), in conjunction with thermodynamic (ISORROPIA-II) and chemical transport (CMAQ) model results. Sulfate and ammonium experienced similar and significant decreases with little change in pH, neutralization ratio ( f = [NH]/2[SO] + [NO]), or nitrate.