P availability often limits primary production in freshwater ecosystems and excessive P inputs promote accelerated eutrophication. Microbial mechanisms may control O2-dependent uptake/release of P in ...stream sediments and biofilms, but specific organisms responsible for these cycles have not been identified. Polyphosphate accumulating organisms (PAOs) are purposely enriched in treatment plants to remove P from wastewater. PAOs release P under anaerobic conditions and take it up under aerobic conditions. We hypothesized that alternating aerobic/anaerobic conditions promote patterns of P uptake/release similar to those attributed to PAOs in wastewater treatment. We collected intact, native stream biofilms and subjected them to laboratory treatments to impose conditions similar to what may occur because of diel oxygenic and respiratory cycles: 1) continuous sparging with air and 2) alternate sparging with air or anaerobic gas (20:80% by volume CO2:N2). We monitored PO4
3−, Ca, Mg, total Mn, K, Fe2+, and total S (TS) concentrations in the water during the experiment and total P (TP) and polyphosphate (polyP) concentrations in the biofilms at the start and end of the experiment. We used microscopy and polymerase chain reaction (PCR) to quantify the percentage of cells with stored intracellular polyP and to test for known PAO genes, respectively. The water had significantly greater dissolved PO4
3− concentrations during anaerobic than during aerobic conditions. Ca, K, Mg, and total Mn concentrations mimicked PO4
3− concentrations over time, but Fe2+ and TS concentrations did not. Precipitation of Ca and Mg and reductive dissolution of Mn may have influenced P cycling. Percent microbially stored intracellular polyP was nearly 3× greater in aerobic than anaerobic conditions. We did not find previously reported PAO genes in our biofilms, indicating the presence of novel polyP accumulators. Combined biotic and abiotic processes may be important in controlling short-term P cycling in stream biofilms.
A Technical Overview of the North Carolina ECONet Saia, Sheila M.; Heuser, Sean P.; Neill, Myleigh D. ...
Journal of atmospheric and oceanic technology,
06/2023, Letnik:
40, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Abstract
Regional weather networks—also referred to as mesonets—are imperative for filling in the spatial and temporal data gaps between nationally supported weather stations. The North Carolina ...Environment and Climate Observing Network (ECONet) fills this regional role; it is a mesoscale network of 44 (as of 2023) automated stations collecting 12 environmental variables every minute across North Carolina. Measured variables include air temperature, precipitation, relative humidity, barometric pressure, wind speed, wind direction, total solar radiation, photosynthetically active solar radiation, soil temperature, soil moisture, leaf wetness index, and black globe temperature. All data undergo quality control procedures and are made freely available to the public via data portals hosted by the State Climate Office of North Carolina at North Carolina State University. This paper provides a technical overview of ECONet, including a description of the siting criteria, station maintenance procedures, data quality control procedures, and data availability. We also summarize unique aspects of ECONet data collection as well as innovative research and applications that rely on ECONet data. ECONet data are used by many sectors including, but not limited to, emergency management, natural resources management, public health, agriculture, forestry, science education, outdoor recreation, and research. ECONet data and data-powered applications offer valuable insights to local, regional, and federal partners, yet opportunities to expand ECONet research and applications remain.
Significance Statement
This paper explains the ongoing and emerging impacts of a statewide weather station network called the North Carolina Environment and Climate Observing Network (ECONet). ECONet consists of 44 (as of 2023) automated stations located across the state. Each station collects 12 environmental variables every minute. ECONet data and data-powered applications offer valuable insights to local, regional, and federal partners. There are many opportunities to expand ECONet-based research and applications.
Private wells in Cayuga and Orange counties in New York were sampled to determine the occurrence of pesticide contamination of groundwater in areas where significant pesticide use coincides with ...shallow or otherwise vulnerable groundwater. Well selection was based on local groundwater knowledge, risk modeling, aerial photo assessments, and pesticide application database mapping. Single timepoint samples from 40 wells in each county were subjected to 93‐compound chromatographic scans. All samples were nondetects (reporting limits ≤1 μg/L), thus no wells from either county exceeded any of 15 state groundwater standards or guidance values. More sensitive enzyme‐linked immunosorbent assays (ELISA) found two wells with quantifiable atrazine in each county (0.1–0.3 μg/L), one well with quantifiable diazinon (0.1 μg/L) in Orange County, and one well with quantifiable alachlor (0.2 μg/L) in Cayuga County. Trace detections (<0.1 μg/L) in Cayuga County included atrazine (five wells), metolachlor (six wells), and alachlor (one well), including three wells with multiple detections. All 12 Cayuga County wells with ELISA detections had either corn/grain or corn/forage rotations as primary surrounding land uses (although 20 other wells with the same land uses had no detections) and all quantified detections and most trace detections occurred in wells up to 9‐m deep. Orange County trace (<0.1 μg/L) ELISA detections (atrazine three wells, diazinon one well, and metolachlor five wells) and quantified detections were only generally associated with agricultural land uses. Finding acceptable drinking water quality in areas of vulnerable groundwater suggests that water quality in less vulnerable areas will also be good.
Best management practice (BMP) tools that provide site-specific water quality assessment with limited input data are needed to assist soil and water managers as they work to target BMP placement and ...reduce dissolved and sediment bound pesticide loss from agricultural landscapes. BMP effectiveness largely depends on accurate characterization of dominant regional hydrologic processes. However, most BMP tools are region specific in their characterization of hydrology (e.g., most models capture either infiltration excess runoff or saturation excess runoff but cannot predict a combination of the two). In this study, we develop and couple a pesticide transport module with the Water Erosion Prediction Project (WEPP) model (v2012.8). The WEPP model realistically simulates infiltration excess and saturation excess runoff as well as dissolved pesticide loss from hillslopes in the Goodwater Creek Experimental Watershed (GCEW) in northeastern Missouri. Simulated runoff and dissolved atrazine concentrations were compared to observed data from mulch till (MT) and no till (NT) plots in the GCEW. The timing of runoff predicted by WEPP coincided well with observed events and simulated flow magnitudes were between minimum and maximum observations for replicate plots. Event-based Nash-Sutcliffe Efficiencies (NSE) are 0.84 and 0.79 for MT and NT runoff simulations, respectively. Both simulations and observations showed little difference in total growing season (planting to harvest) runoff between MT and NT. Event-based dissolved atrazine loads are well predicted for MT and NT with NSEs of 0.59 and 0.71, respectively. Consistent with observations, seasonal NT atrazine losses were greater than losses from MT plots. While this study only focuses on dissolved pesticide transport from the base of hillslopes using MT and NT conservation practices, the WEPP pesticide transport module is capable of predicting both dissolved and sediment bound pesticide loss from each section of the hillslope (i.e., top-slope, mid-slope, and toe-slope) for a wide range of BMPs. However, further field data are needed to evaluate these aspects of the model.
We started this exploration with a review of PAOs in engineered and natural systems—we discussed knowledge gaps and ways studies from these distinct contexts may build on one another. This review ...also included a discussion of the potential role of PAOs in agricultural systems. We proposed studies to explore the impacts of PAOs in terms of major agricultural challenges and discussed how these studies may inform our understanding of PAOs in engineered and natural systems. Next, we conducted a laboratory experiment to explore the role of PAO-mediated P cycling in stream biofilms under alternating aerobic and anaerobic conditions. We demonstrated cyclical patterns of P uptake under aerobic conditions and release during anaerobic conditions, which is consistent with the known behavior of PAOs in WWTPs. We also verified larger percentages of cells with stored intracellular polyphosphate granules under aerobic conditions compared to anaerobic conditions, which we expected given our understanding of the PAO phenotype in WWTPs. However, we observed concurrent patterns in cation uptake and release, which may indicate abiotic precipitation/dissolution of P with these cations and/or biotic uptake/release of these cations to balance the negative charge of intracellular polyP. Next, we explored whether the soil wetness index (SWI), a static index used to predict landscape scale soil moisture patterns, can predict the occurrence of mobile forms of P as well as PAO associated functional genes (i.e., ppk1, ppk2, and ppx). We showed that SWI predicted mobile P (i.e., dilute CaCl 2 extractable P) and there was a depletion of mobile P from wetter parts of the landscape. This is consistent with our expectations of PAO behavior; PAOs release mobile forms of P under saturated conditions that are transported off-site. More specifically related to PAOs, we found that SWI was not a good predictor of the relative abundance of polyP functional genes. We observed a general decrease in the relative abundance polyP functional genes versus mobile P concentrations in NY, was consistent with our hypothesis, but this trend was only statistically significant in the case of ppk2. In PA, the relationship between the relative abundance of polyP functional genes was not significant and general trends were inconsistent with our hypothesis. Therefore, these results suggest the limited role of PAO-mediated P cycling along the SWI gradients identified and the potential masking of PAOs by other P controls (e.g. landscape position and management). Future research may consider how the role of biotic and abiotic processes masks the role of PAOs in soil P cycling. These includes the impact of iron reducing bacteria or chemical iron reduction/dissolution with P along a SWI gradient. Despite this limited support for PAOs, we identified contigs harboring both ppk1 and ppx genes that were within the same phyla as known PAOs as well as many unstudied, putative PAOs. Last, we studied whether PAOs played a discernable role in P cycling associated with the decomposition of leaf litter in the stream and on the forest floor. We observed an increase in leaf P concentrations in the stream and a decrease in leaf P concentrations on the forest floor over time. Unexpectedly, we did not observe a concurrent increase in the relative abundance of PAO-associated functional genes over time in the stream. Rather these genes remained constant. ppk1 and ppx relative abundances also remained constant in the forest floor but the relative abundance of ppk2 genes increased over time. While these trends did not provide support for PAOs control on P cycling in leaf litter decomposition, we identified contigs harboring both ppk1 and ppx genes that were within the same phyla as known PAOs as well as many unstudied, putative PAOs just as we observed in the soil study. In the case of both soil and leaf litter experiments, future studies may consider using microscopy and molecular biology tools to verify whether putative PAOs exhibit the phenotype of PAO established in engineered systems. Overall, we found support for PAO-mediated P cycling in stream biofilms but only limited support for their impact on P cycling in soils along a SWI gradient as well as on decomposing leaf P patterns over time. We provided additional thoughts at the end of the review paper and in chapter five on how these studies can be modified to test for the potential role of PAOs in agricultural P management as well as the influence of hydrology and nutrient demand/availability on PAO-mediated P cycling. (Abstract shortened by ProQuest.)
Psychiatric disorders are one of the biggest burdens to society, with significant personal and economical costs. Schizophrenia (SCZ), among them, is still poorly understood, and its molecular ...characterization is crucial to improve patients' diagnosis and treatment. The combination of genetic, biochemical, and environmental factors leads to systemic alterations, which are yet to be fully comprehended. Thus, understanding those missing links by connecting some molecular reports of SCZ is essential. From postmortem brain to animal models and cell culture, new tools are emerging, including recent advances in proteomics, and there is a need to apply them to solve these problems. Here, we review some of those features, mainly related to where proteomics could help, and discuss whether those new technologies could and should be applied to psychiatric disorder studies.
Farmers rely on best management practices to reduce pesticide transport to surface waters and groundwater. There are a variety of tools available to help soil and water conservation managers optimize ...agricultural best management practices (BMPs), but many require a considerable amount of time to calibrate and/or advanced training to use. More often than not, these same BMP tools also fail to accurately identify dominant hydrological processes, and thus, the location of runoff generating areas. More specifically, commonly used BMP selection tools are capable of predicting either infiltration excess runoff or saturation excess runoff but not both. Many studies have shown that saturated areas in the landscape are more likely to contribute dissolved and sediment bound contaminates. Therefore, an easy-to-use tool that can accurately characterize local hydrology is needed to assist soil and water managers as they work to target management practices and reduce pesticides transport. In this study we present a simple online BMP selection tool and compare simulated versus observed atrazine loads under different tillage conditions in the Goodwater Creek Watershed of northeastern Missouri. Results indicate a reasonable fit for runoff and dissolved atrazine concentrations but more research is needed to improve the accuracy and usability of this tool.
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