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Shoreline responses to rapid water level increases in Lake Michigan
No full textHigh-resolution multispectral satellite imagery was utilized to quantify shoreline recession at eleven beaches around Lake Michigan during a record-setting water level increase between 2013 and 2020. Shoreline changes during this period ranged from 20 m to 62 m, corresponding to 52–95 % of the initial beach widths. Average estimated shoreline erosion across all beaches varied from 1 % to 75 % of the observed changes, with the remainder attributed to inundation. Significant correlations were found between shoreline erosion and wave-related factors, including offshore wave power, offshore bathymetric slope, storm energy, and potential alongshore sediment transport divergence. In contrast, parameters related to cross-shore transport, such as dimensionless fall velocity, exhibited weak correlations. Additionally, the results underscore the importance of distinguishing between immediately reversible changes (inundation) and morphological changes that could be reversible over longer timescales, when assessing the impact of rising water levels. The findings also suggest that in addition to waves playing a key role in regulating shoreline changes, alongshore sediment transport processes may play a more crucial role in beach erosion during significant water level increases than cross-shore processes, challenging traditional models of beach adjustment to rising waters
Effect of hygrothermal environment on properties of bagasse fibers and asphalt binders/mixtures with bagasse fibers
No full textTo explore the effect of the hygrothermal environment on the properties of materials, the hygrothermal cycling aging tests were performed for bagasse fibers and asphalt binders/mixtures with bagasse fibers and lignin fibers were used as the control groups. Subsequently, Fourier transform infrared spectroscopy, supported by thermogravimetric analysis, was implemented to analyze the influence of the hygrothermal environment on chemical composition and thermal stability of samples. Then, a series of rheological tests analyzed the viscoelastic behavior of asphalt binders with plant fibers. Finally, the performance of fiber asphalt mixtures was evaluated through indirect tensile strength tests. The results revealed that with the increase of hygrothermal cycles, the main components of plant fibers were gradually degraded, and especially, hemicellulose degradation was the most severe within them. The hygrothermal cycles would reduce the thermal stability of plant fibers and the thermal stability of binders with fibers could be improved. After 50 hygrothermal cycles, the creep recovery ability of plant fiber asphalt binders was weakened and the fatigue lives of bagasse fibers and lignin fibers were reduced by 38.6 % and 35.7 % at the strain levels of 5 %, respectively. Moreover, the indirect tensile strengths of plant fiber asphalt mixtures decreased by 39.5 % and 44.0 %, respectively. It was evident that bagasse fibers and asphalt could provide better aging resistance protection for each other. In addition, bagasse fibers and lignin fibers exhibited similar abilities to reduce the effect of hygrothermal environment on the properties of asphalt binders
Sensitivity of Left Atrial Flow Dynamics to Echocardiographic and Computed Tomography Data
No full textComputational simulations are a powerful tool in the understanding, diagnosing, and treatment of cardiovascular diseases. Incomplete clinical data often limits computational assessment, which may lead to inaccuracies. This study aims to assess the sensitivity of left atrial flow dynamics to echocardiographic and computed tomography data. Models of the LA were reconstructed at the E-wave(Geometry 1)and end-diastolic(Geometry 2)phases from CT scans. CFD simulations were carried out using 3 different sets of BCs. BC2 and BC3 presented similar results that were significantly different from BC1. The effect from the choice of geometry was significant with BC2 and BC3 but minor with BC1. Differences in parameters across the simulated cases highlight the importance of using consistent BCs and geometries for CFD studies. Acquiring the pressure in the LA does not seem to be necessary for the accuracy of CFD simulations. Validation of all simulations indicates reliable patient-specific results
Conservation in conflict: Examining rural–urban discourse in wolf reintroduction policy in Colorado
No full textWolf reintroduction and management is a highly conflictual topic in both the United States and Europe, enflaming rural–urban tensions and pitting agriculture interests against environmentalists. This study examines the case of gray wolf reintroduction in Colorado. The reintroduction decision was decided by state popular vote on a citizen-introduced ballot initiative, Proposition 114, in 2020. While a majority of Coloradans voted in favor of reintroduction, this vote was almost exclusively divided along rural–urban geographic lines. To analyze these cleavages and the conflict therein, this study examines the changing coalitional discourse surrounding wolf reintroduction policy in Colorado. This study captures changes in the policy conflict from the beginning of 2020 when the ballot initiative to reintroduce gray wolves was first proposed, to the passage of that initiative on the November 2020 ballot, through the related legislative bills proposed in the spring of 2021 in an effort to maintain rural representation in the reintroduction process. This case utilizes the advocacy coalition framework (ACF) and emotion belief analysis (EBA) to analyze news media and legislative testimony
A New Method Using Deep Learning to Predict the Response to Cardiac Resynchronization Therapy
No full textClinical parameters measured from gated single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) have value in predicting cardiac resynchronization therapy (CRT) patient outcomes, but still show limitations. The purpose of this study is to combine clinical variables, features from electrocardiogram (ECG), and parameters from assessment of cardiac function with polar maps from gated SPECT MPI through deep learning (DL) to predict CRT response. A total of 218 patients who underwent rest-gated SPECT MPI were enrolled in this study. CRT response was defined as an increase in left ventricular ejection fraction (LVEF) \u3e 5% at a 6-month follow-up. A DL model was constructed by combining a pre-trained VGG16 model and a multilayer perceptron. Two modalities of data were input to the model: polar map images from SPECT MPI and tabular data from clinical features, ECG parameters, and SPECT-MPI-derived parameters. Gradient-weighted class activation mapping (Grad-CAM) was applied to the VGG16 model to provide explainability for the polar maps. For comparison, four machine learning (ML) models were trained using only the tabular features. Modeling was performed on 218 patients who underwent CRT implantation with a response rate of 55.5% (n = 121). The DL model demonstrated average AUC (0.83), accuracy (0.73), sensitivity (0.76), and specificity (0.69) surpassing ML models and guideline criteria. Guideline recommendations achieved accuracy (0.53), sensitivity (0.75), and specificity (0.26). The DL model trended towards improvement over the ML models, showcasing the additional predictive benefit of utilizing SPECT MPI polar maps. Incorporating additional patient data directly in the form of medical imagery can improve CRT response prediction
Demand Response Potential of Drinking Water Distribution Networks
No full textPumps in drinking water distribution networks can be controlled to participate in demand response programs. In this paper, we estimate the demand response potential of water distribution networks based on actual network data. We calculate the power and energy capacities of community water systems within Wisconsin and Arizona, drawing on publicly available data of consumer water demand, population served, storage tanks, and pump specifications. We then extrapolate this data to get an order-of-magnitude estimate for the entire United States. Overall, we found that water distribution networks are sizable demand response assets with an estimated power capacity of 13 GW and energy capacity of 750 GWh in the United States. We also found that large and very large utilities may be the best demand response candidates. This paper also discusses factors impacting water supply flexibility and future research directions
Simulating Droplet-Resolved Haze and Cloud Chemistry Forming Secondary Organic Aerosols in Turbulent Conditions within Laboratory and Cloud Parcels
No full textMost models do not explicitly simulate droplet-resolved cloud chemistry and the interactions between turbulence and cloud chemistry due to large associated computational costs. Here, we incorporate the formation of isoprene epoxydiol secondary organic aerosol (IEPOX-SOA) in individual droplets within a one-dimensional explicit mixing parcel model (EMPM-Chem). We apply EMPM-Chem to simulate turbulence and droplet-resolved IEPOX-SOA formation using a laboratory cloud chamber configuration. We find that the dissolution of IEPOX gases is weighted more toward larger cloud droplets due to their large liquid water content (compared to smaller droplets), while the conversion of dissolved IEPOX to IEPOX-SOA is much greater within smaller deliquesced haze particles due to their higher acidity and ionic strengths compared to cloud droplets. We also apply the EMPM-Chem model to simulate how IEPOX-SOA formation evolves in individual cloud droplets within rising cloudy parcels in the atmosphere. We find that as subsaturated air is entrained into and turbulently mixed with the cloud parcel, evaporation causes a reduction in droplet sizes, which leads to corresponding increases in per droplet ionic strength and acidity. Increased droplet acidity, in turn, greatly accelerates the kinetics of IEPOX-SOA formation. Our results provide key insights into single cloud-droplet chemistry, suggesting that entrainment mixing may be an important process that increases SOA formation in the real atmosphere
Removal of Per- and Polyfluoroalkyl Substances Using Commercially Available Sorbents
Get PDFPer- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants of growing environmental and human health concern, widely detected across various environmental compartments. Effective remediation strategies are essential to mitigate their widespread impacts. This study compared the performance of two types of commercially available sorbent materials, granular activated carbon (GAC, Filtrasorb-400) and organoclays (OC-200, and modified organoclays Fluoro-sorb-100 and Fluoro-sorb-200) for the removal of three representative PFAS compounds: perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorooctane sulfonic acid (PFOS) from water. Both organoclays and modified organoclays outperformed GAC, likely due to electrostatic interactions between the anionic PFAS compounds and the cationic functional groups of the modified organoclays. A pseudo-second-order kinetic model best described the rapid sorption kinetics of PFOA, PFNA, and PFOS. For PFOA, OC-200 demonstrated the highest adsorption capacities (qmax = 47.17 µg/g). For PFNA and PFOS, Fluoro-sorb-100 was the most effective sorbent, with qmax values at 99.01 µg/g and 65.79 µg/g, respectively. Desorption studies indicated that the sorption of the three PFAS compounds on these commercially available sorbents was largely irreversible. This study highlights the effectiveness and sorption capacities of different types of commercial sorbents for PFAS removal and offers valuable insights into the selection of reactive media for PFAS removal from water under environmentally relevant conditions
Biochemical, Structural, and Conformational Characterization of a Fungal Ethylene-Forming Enzyme
Get PDFThe ethylene-forming enzyme (EFE) from the fungus Penicillium digitatum strain Pd1 was heterologously produced in Escherichia coli and its properties were compared to the extensively characterized bacterial enzyme from Pseudomonas savastanoi strain PK2. Both enzymes catalyze four reactions: the conversion of 2-oxoglutarate (2OG) to ethylene and CO2, oxidative decarboxylation of 2OG coupled to L-arginine (L-Arg) hydroxylation, uncoupled oxidative decarboxylation of 2OG, and the production of 3-hydroxypropionate (3-HP) from 2OG. The strain Pd1 enzyme exhibited a greater ratio of ethylene production over L-Arg hydroxylation than the PK2 strain EFE. The uncoupled decarboxylation of 2OG and 3-HP production are minor reactions in both cases, but they occur to a greater extent using the fungal enzyme. Additional distinctions of the fungal versus bacterial enzyme are noted in the absorbance maxima and L-Arg dependence of their anaerobic electronic spectra. The structures of the Pd1 EFE apoprotein and the EFE·Mn(II)·2OG complex resembled the corresponding structures of the PK2 enzyme, but notable structural differences were observed in the computationally predicted Pd1 EFE·Fe(II)·2OG·L-Arg complex versus the PK2 EFE·Mn(II)·2OG·L-Arg crystal structure. These studies extend our biochemical understanding and represent the first structural and conformational characterization of a eukaryotic EFE
