Background: Forests are significant terrestrial biomes for carbon storage, and annual carbon accumulation of forest biomass contributes offsets affecting net greenhouse gases in the atmosphere. The immediate loss of stored carbon through fire on forest lands reduces the annual offsets provided by forests. As such, the United States reporting includes annual estimates of direct fire emissions in conjunction with the overall forest stock and change estimates as a part of national greenhouse gas inventories within the United Nations Framework Convention on Climate Change.
View Article and Find Full Text PDFJ Glob Antimicrob Resist
September 2024
Objective: Carbapenem-resistant Acinetobacter baumannii (CRAB) is a global concern as effective treatments are very limited. We previously used a modified susceptibility testing approach to predict growth suppression in carbapenem-resistant Enterobacterales, but there are uncertainties about the generalizability of the model. The objective of this study is to verify if a similar approach can be extended to CRAB.
View Article and Find Full Text PDFObjectives: Aminoglycosides and polymyxins are antibiotics with in vitro activity against MDR Gram-negative bacteria. However, their clinical use is hindered by dose-limiting nephrotoxicity. The objective of this project was to determine if zileuton can reduce nephrotoxicity associated with amikacin and polymyxin B in a rat model of acute kidney injury.
View Article and Find Full Text PDFInt J Antimicrob Agents
October 2023
Objective: The prevalence of drug resistance in pathogens such as HIV and selected bacteria has been steadily rising, resulting in an increased need for using multiple agents concurrently. Agents used in these combination therapies may have different elimination half-lives in humans. There is an unmet need for in vitro models to evaluate the efficacy of these combinations to guide early drug development.
View Article and Find Full Text PDFIn the United States (US), forest ecosystems are the largest terrestrial carbon sink, offsetting the equivalent of >12 % of economy-wide greenhouse gas (GHG) emissions annually. In the Western US, wildfires have shaped much of the landscape by changing forest structure and composition, increasing tree mortality, impacting forest regeneration, and influencing forest carbon storage and sequestration capacity. Here, we used remeasurements of >25,000 plots from the US Department of Agriculture, Forest Service Forest Inventory and Analysis (FIA) program and auxiliary information (e.
View Article and Find Full Text PDFBackground: Sequestration of carbon on forest land is a common and practical component within many climate action plans developed by state or municipal governments. Initial planning often identifies the general magnitude of sequestration expected given the scope of the project. Because age plays a key role in forest carbon dynamics, we summarize both the carbon stock and accumulation rates in live trees by age class and region, allowing managers and policymakers to assess the influence of forest age class structure on forest carbon storage as represented in current inventories.
View Article and Find Full Text PDFDowned woody material (DWM) is a unique part of the forest carbon cycle serving as a pool between living biomass and subsequent atmospheric emission or transference to other forest pools. Thus, DWM is an individually defined pool in national greenhouse gas inventories. The diversity of DWM carbon drivers (e.
View Article and Find Full Text PDFJAMA Netw Open
August 2021
Importance: The success of direct-acting antiviral therapies for chronic hepatitis C virus (HCV) infection led the World Health Organization to set elimination targets by 2030. For the United States to achieve these benchmarks, public health responses must target high-risk populations, such as people who inject drugs (PWID), a group with high rates of HCV incidence and low rates of treatment uptake.
Objective: To evaluate potential improvements in the HCV care cascade among PWID, focusing on improved testing, treatment uptake, and access to harm reduction.
Background: With the introduction of the Trillion Trees Initiative and similar programs, forests' ability to absorb carbon dioxide is increasingly in the spotlight. Many states have mandates to develop climate action plans, of which forest carbon is an important component, and planners need current information on forest carbon stocks and rates of change at relevant spatial scales. To this end, we examine rates of average annual change in live aboveground tree carbon in different forest type groups and provide state-wide and regional summaries of current live tree carbon stock and rates of change for the forests of the conterminous United States.
View Article and Find Full Text PDFMany types of contaminants of emerging concern (CECs), including per- and poly-fluoroalkyl substances (PFAS), have been found in leachate of operating municipal landfills. However, there is only limited information on CECs presence in leachate of historic landfills (≥3 decades since closure, often lacking engineered liners or leachate collection systems) at concentrations that may pose a risk to nearby wells and surface water ecosystems. In this study, 48 samples of leachate-impacted groundwater were collected from 20 historic landfills in Ontario, Canada.
View Article and Find Full Text PDFGroundwater contamination from ethanol (e.g., alternative fuels) can support vigorous biodegradation, with many possible reactions producing dissolved gases.
View Article and Find Full Text PDFThe use of ethanol in alternative fuels has led to contamination of groundwater with high concentrations of this easily biodegradable organic compound. Previous laboratory and field studies have shown vigorous biodegradation of ethanol plumes, with prevalence of reducing conditions and methanogenesis. The objective of this study was to further our understanding of the dynamic biogeochemistry processes, especially dissolved gas production, that may occur in developing and aging plume cores at sites with ethanol or other organic contamination of groundwater.
View Article and Find Full Text PDFVariation in FOXC1 and PITX2 is associated with Axenfeld-Rieger syndrome, characterised by structural defects of the anterior chamber of the eye and a range of systemic features. Approximately half of all affected individuals will develop glaucoma, but the age at diagnosis and the phenotypic spectrum have not been well defined. As phenotypic heterogeneity is common, we aimed to delineate the age-related penetrance and the full phenotypic spectrum of glaucoma in FOXC1 or PITX2 carriers recruited through a national disease registry.
View Article and Find Full Text PDFWe present electronic spectra in the π-π* region of a series of tris(bpy)-M(II) complex ions (bpy = 2,2'-bipyridine; M = Mn, Fe, Co, Ni, Cu, Zn) in vacuo for the first time. By applying photodissociation spectroscopy to cryogenically cooled and mass selected [M(bpy)] ions, we obtain the intrinsic spectra of these ions at low temperature without perturbation by solvent interaction or crystal lattice shifts. This allows spectroscopic analysis of these complex ions in greater detail than possible in the condensed phase.
View Article and Find Full Text PDFWe report the electronic spectra of mass selected [(bpy)(tpy)Ru-OH]·(HO) clusters (bpy = 2,2'-bipyridine, tpy =2,2':6'2″-terpyridine, n = 0-4) in the spectral region of their metal-to-ligand charge transfer bands. The spectra of the mono- and dihydrate clusters exhibit partially resolved individual electronic transitions. The water network forming at the aqua ligand leads to a rapid solvatochromic shift of the peak of the band envelope: addition of only four solvent water molecules can recover 78% of the solvatochromic shift in bulk solution.
View Article and Find Full Text PDFWe report the electronic spectrum of the prototypical ruthenium coordination complex Ru(bpy)3 (2+) (bpy = 2, 2'-bipyridine) by messenger tagging with N2 in a cryogenic ion trap and photodissociation spectroscopy of mass selected Ru(bpy)3 (2+) ⋅ N2 ions. We observe individual electronic bands and groups of bands with unprecedented detail, particularly in the usually unresolved metal-to-ligand charge transfer region of the spectrum. By comparing our experimental results with time-dependent density functional theory, both with and without spin-orbit interaction [Heully et al.
View Article and Find Full Text PDFWe report electronic spectra of a series of ruthenium polypyridine complexes of the form [(trpy)(bipy)Ru(II)-L](2+) (bipy = 2,2'-bipyridine and trpy = 2,2':6',2″-terpyridine), where L represents a small molecular ligand that occupies the last coordination site. Species with L = H2O, CO2, CH3CN, and N2 were investigated in vacuo using photodissociation spectroscopy. All species exhibit bright metal-to-ligand charger transfer (MLCT) bands in the visible and near UV, but with different spectral envelopes and peak energies, encoding the influence of the ligand L on the electronic structure of the complex.
View Article and Find Full Text PDFForest ecosystems are the largest terrestrial carbon sink on earth, with more than half of their net primary production moving to the soil via the decomposition of litter biomass. Therefore, changes in the litter carbon (C) pool have important implications for global carbon budgets and carbon emissions reduction targets and negotiations. Litter accounts for an estimated 5% of all forest ecosystem carbon stocks worldwide.
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