Regulatory Mechanisms in Biosystems (E-Journal - Dnipro National University)
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Molecular characterization of dissolved organic matter in Sao Paulo, Brazil wet deposition by ultra-high resolution mass spectrometry
No full textRainwater dissolved organic matter (DOM) is a complex mixture of organic compounds, the composition of which remains to a large extent unknown. This is despite its central role in a host of fundamentally important atmospheric processes (e.g. aerosol hygroscopicity, light absorption, etc.). The molecular composition of DOM has been used to infer emission sources and investigate atmospheric reactions that produce secondary organic aerosols (SOA), which comprise the main contributor of uncharacterized compounds in rainwater organics. This work illustrates the molecular composition of DOM in rainwater collected from February 2020 to June 2021 (n = 32 of rain samples) in Ribeirão Preto, SP (21.166 S, 47.845 W) using complimentary methods of traditional ion chromatography cooperatively with Orbitrap mass spectrometry and novel statistical analysis. This approach provides a detailed, ultra-high resolution, high throughput method for future rainwater DOM investigations which is demonstrated here with direct-injection, positive mode electrospray ionization. Using this method, 41,383 total molecular formulas in 32 samples were identified over the mass range m/z+ range of 80 to 800; among them 2,788 molecular formulas were unique. DOM character in São Paulo rainwater is revealed to be largely influenced by organic nitrogen, as 2,397 of the unique formulas identified contained nitrogen. This represents 86.0% of the total variety of organic compounds identified, with many of these likely peptides or amino acid derivatives. These findings also show that in terms of variety and number the general proportions of elemental formula classes remain relatively consistent over many samples, but the composition of the individual classes varies as function of its constituent emission sources. Recent pandemic related influences on anthropogenic activity as well as biomass burning in the São Paulo region of Brazil are seen through variations in rainwater DOM characteristics. Rainwater collected prior to the COVID-19 pandemic’s emergence in Brazil is distinct from reduced anthropogenic activity rainwater in both DOM character—seen in the increase in primary compounds and direct amino acid contribution, wider range of O:C ratios, and the absence of atmospheric NOx related CHON oligomers—and major ion content—marked by a reduction in sulfate, nitrate, potassium, and formate. Clustering analysis shows that these distinctions are mostly driven by changes in anthropogenic reactive nitrogen emissions as well as in part to seasonal influence. This research highlights the potential for public policy to reduce the emission of air pollutants and other biologically relevant anthropogenic emissions, particularly through reducing traffic loading and expanding remote working.Physical and Environmental SciencesCollege of Science and Engineerin
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Filling temporal gaps within and between GRACE and GRACE-FO terrestrial water storage records: An innovative approach
No full textTemporal gaps within the Gravity Recovery and Climate Experiment (GRACE) (gap: 20 months), between GRACE and GRACE Follow-On (GRACE-FO) missions (gap: 11 months), and within GRACE-FO record (gap: 2 months) make it difficult to analyze and interpret spatiotemporal variability in GRACE- and GRACE-FO-derived terrestrial water storage (TWSGRACE) time series. In this study, an overview of data and approaches used to fill these gaps and reconstruct the TWSGRACE record at the global scale is provided. In addition, the study provides an innovative approach that integrates three machine learning techniques (deep-learning neural networks [DNN], generalized linear model [GLM], and gradient boosting machine [GBM]) and eight climatic and hydrological input variables to fill these gaps and reconstruct the TWSGRACE data record at both global grid and basin scales. For each basin and grid cell, the model performance was assessed using Nash–Sutcliffe efficiency coefficient (NSE), correlation coefficient (CC), and normalized root-mean-square error (NRMSE), a leader model was selected based on the model performance, and variables that significantly control leader model outputs were defined. Results indicate that (1) the leader model reconstructed the TWSGRACE with high accuracy over both grid and local scales, particularly in wet and low anthropogenically active regions (grid scale: NSE = 0.65 ± 0.20, CC = 0.81 ± 0.13, and NSE = 0.56 ± 0.16; basin scale: NSE = 0.78 ± 0.14, CC = 0.89 ± 0.07, and NRMSE = 0.43 ± 0.14); (2) no single model was flawless in reconstructing the TWSGRACE over all grids or basins, so a combination of models is necessary; (3) basin-scale models outperform grid-scale models; (4) the DNN model outperforms both GLM and GBM at the basin scale, whereas the GBM outperforms at the grid scale; (5) among other inputs, the Global Land Data Assimilation System (GLDAS)-derived TWS controls the model performance on both basin and grid scales; and (6) the reconstructed TWSGRACE data captured extreme climatic events over the investigated basins and grid cells. The developed approach is robust, effective, and could be used to accurately reconstruct TWSGRACE for any hydrologic system across the globe
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No full textPicture of a group of people sitting by the beach with two cars in the backgroun
Land subsidence estimation with tide gauge and satellite radar altimetry measurements along the Texas Gulf Coast, USA
No full textA double-difference (DD) method was used to esti mate vertical land motion (VLM) at 26 tide gauge (TG) sites with record lengths of at least ten years across the Texas Gulf Coast, USA, between 1993 and 2020. In the method, the first difference was conducted by coupling nearby correlated TG stations to remove sea-level variability for both TG and satellite radar altimetry (SRA) data. Upon completion of the first difference, a second difference was performed by subtracting between TG and SRA data. The results obtained from the DD method were compared against that of: 1) a single-difference (SD) method through subtraction between measurements from TG and SRA and 2) a global navigation satellite system (GNSS) precise point positioning (PPP) method. The results showed that the DD method improved the performance of VLM estimation with an uncertainty below 1.0 mm/yr at most TG stations. Meanwhile, the estimated VLM trends acquired from the DD method corre lated better to that of the ground-truth GNSS PPP solutions than the SD method. The DD method possesses great potential to dis cover VLM knowledge, particularly along coastal regions where other techniques such as GNSS and interferometric synthetic aperture radar (InSAR) are of impaired estimation capability.A double-difference (DD) method was used to esti mate vertical land motion (VLM) at 26 tide gauge (TG) sites with record lengths of at least ten years across the Texas Gulf Coast, USA, between 1993 and 2020. In the method, the first difference was conducted by coupling nearby correlated TG stations to remove sea-level variability for both TG and satellite radar altimetry (SRA) data. Upon completion of the first difference, a second difference was performed by subtracting between TG and SRA data. The results obtained from the DD method were compared against that of: 1) a single-difference (SD) method through subtraction between measurements from TG and SRA and 2) a global navigation satellite system (GNSS) precise point positioning (PPP) method. The results showed that the DD method improved the performance of VLM estimation with an uncertainty below 1.0 mm/yr at most TG stations. Meanwhile, the estimated VLM trends acquired from the DD method corre lated better to that of the ground-truth GNSS PPP solutions than the SD method. The DD method possesses great potential to dis cover VLM knowledge, particularly along coastal regions where other techniques such as GNSS and interferometric synthetic aperture radar (InSAR) are of impaired estimation capability.This work was supported by the U.S. Department of Commerce-National Oceanic and Atmospheric Administration (NOAA) through the University of Southern Mississippi (USM) under Agreement NA13NOS4000166.This work was supported by the U.S. Department of Commerce-National Oceanic and Atmospheric Administration (NOAA) through the University of Southern Mississippi (USM) under Agreement NA13NOS4000166
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Photograph of four workers mixing concrete for the Bluff Balustrade
No full textPhotograph of four workers mixing concrete for the Bluff Balustrad
Holly Beauty Salon
No full textHolly Beauty Salon on 607 S.Staples, with clinets sitting down and hairdressers standin
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No full textPicture of a gentleman and a woman sitting on a chair with a boo