scholarly journals The Dark Side of Microbial Processes: Accumulation of Nitrate During Storage of Surface Water in the Dark and the Underlying Mechanism

2022 ◽  
Author(s):  
Amit Kumar ◽  
Daphne H. P. Ng ◽  
Sakcham Bairoliya ◽  
Bin Cao
Keyword(s):  
Surface Water ◽  
Microbial Communities ◽  
Aquatic Ecosystem ◽  
Essential Role ◽  
Underlying Mechanism ◽  
Microbial Processes ◽  
Dark Side ◽  
Water Reservoirs ◽  
Excess Nitrogen

Microbial communities play an essential role in maintaining a healthy aquatic ecosystem. For example, in surface water reservoirs, microorganisms produce oxygen, break down toxic contaminants, and remove excess nitrogen.

Effect of dynamically varying zone-based hedging policies on the operational performance of surface water reservoirs during climate change

2018 ◽  
Vol 488 (1) ◽  
pp. 277-289 ◽  
Author(s):  
Adebayo J. Adeloye ◽  
Bankaru-Swamy Soundharajan
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
Operational Performance ◽  
Dynamic Hedging ◽  
Water Reservoirs ◽  
Complex Dynamic ◽  
Water Shortages ◽  
Operational Conditions ◽  
Static Hedging ◽  
The Impact

AbstractHedging is universally recognized as a useful operational practice in surface water reservoirs to temporally redistribute water supplies and thereby avoid large, crippling water shortages. When based on the zones of available water in storage, hedging has traditionally involved a static rationing (i.e. supply to demand) ratio. However, given the usual seasonality of reservoir inflows, it is also possible that hedging could be dynamic with seasonally varying rationing ratios. This study examined the effect of static and dynamic hedging policies on the performance of the Pong reservoir in India during a period of climate change. The results show that the reservoir vulnerability was unacceptably high (≥60%) without hedging and that this vulnerability further deteriorated as the catchment became drier due to projected climate change. The time- and volume-based reliabilities were acceptable. The introduction of static hedging drastically reduced the vulnerability to <25%, although the hedging reduction in the water supplied during normal operational conditions was only 17%. Further analyses with dynamic hedging provided only modest improvements in vulnerability. The significance of this study is its demonstration of the effectiveness of hedging in offsetting the impact of water shortages caused by climate change and the fact that static hedging can match more complex dynamic hedging policies.

scholarly journals Mechanical stimulation promotes enthesis injury repair by mobilizing Prx1+ cells via ciliary TGF-β signaling

2021 ◽  
Author(s):  
Han Xiao ◽  
Tao Zhang ◽  
Chang Jun Li ◽  
Yong Cao ◽  
Lin Feng Wang ◽  
...  
Keyword(s):  
Cell Migration ◽  
Rotator Cuff ◽  
Single Cell ◽  
Mechanical Stimulation ◽  
Essential Role ◽  
Primary Cilia ◽  
Underlying Mechanism ◽  
Rna Sequence ◽  
Injury Repair ◽  
Tgf Β1

Proper mechanical stimulation can improve rotator cuff enthsis injury repair. However, the underlying mechanism of mechanical stimulation promoting injury repair is still unknown. In this study, we found that Prx1+ cell was essential for murine rotator cuff enthesis development identified by single-cell RNA sequence and involved in the injury repair. Proper mechanical stimulation could promote the migration of Prx1+ cells to enhance enthesis injury repair. Meantime, TGF-β signaling and primary cilia played an essential role in mediating mechanical stimulation signaling transmission. Proper mechanical stimulation enhanced the release of active TGF-β1 to promote migration of Prx1+ cells. Inhibition of TGF-β signaling eliminated the stimulatory effect of mechanical stimulation on Prx1+ cell migration and enthesis injury repair. In addition, knockdown of Pallidin to inhibit TGF-βR2 translocation to the primary cilia or deletion of IFT88 in Prx1+ cells also restrained the mechanics-induced Prx1+ cells migration. These findings suggested that mechanical stimulation could increase the release of active TGF-β1 and enhance the mobilization of Prx1+ cells to promote enthesis injury repair via ciliary TGF-β signaling.

scholarly journals An equation-free method reveals the ecological interaction networks within complex microbial ecosystems

2016 ◽  
Author(s):  
Kenta Suzuki ◽  
Katsuhiko Yoshida ◽  
Yumiko Nakanishi ◽  
Shinji Fukuda
Keyword(s):  
Time Series ◽  
Microbial Communities ◽  
Microbial Processes ◽  
Interaction Networks ◽  
List Type ◽  
Metagenomic Sequencing ◽  
Ecological Interactions ◽  
Microbial Interaction ◽  
Ecological Interaction ◽  
Dataset Size

AbstractMapping the network of ecological interactions is key to understanding the composition, stability, function and dynamics of microbial communities. In recent years various approaches have been used to reveal microbial interaction networks from metagenomic sequencing data, such as time-series analysis, machine learning and statistical techniques. Despite these efforts it is still not possible to capture details of the ecological interactions behind complex microbial dynamics.We developed the sparse S-map method (SSM), which generates a sparse interaction network from a multivariate ecological time-series without presuming any mathematical formulation for the underlying microbial processes. The advantage of the SSM over alternative methodologies is that it fully utilizes the observed data using a framework of empirical dynamic modelling. This makes the SSM robust to non-equilibrium dynamics and underlying complexity (nonlinearity) in microbial processes.We showed that an increase in dataset size or a decrease in observational error improved the accuracy of SSM whereas, the accuracy of a comparative equation-based method was almost unchanged for both cases and equivalent to the SSM at best. Hence, the SSM outperformed a comparative equation-based method when datasets were large and the magnitude of observational errors were small. The results were robust to the magnitude of process noise and the functional forms of inter-specific interactions that we tested. We applied the method to a microbiome data of six mice and found that there were different microbial interaction regimes between young to middle age (4-40 week-old) and middle to old age (36-72 week-old) mice.The complexity of microbial relationships impedes detailed equation-based modeling. Our method provides a powerful alternative framework to infer ecological interaction networks of microbial communities in various environments and will be improved by further developments in metagenomics sequencing technologies leading to increased dataset size and improved accuracy and precision.

scholarly journals Formulated Mathematical Model for Delayed Particle Flow in Cascaded Sub-Surface Water Reservoirs with Validation on River Flow

2018 ◽  
Author(s):  
Ombaki Richard ◽  
Kerongo Joash ◽  
Okwoyo M. James
Keyword(s):  
Mathematical Model ◽  
Time Delay ◽  
Surface Water ◽  
Discrete Time ◽  
River Flow ◽  
Water Reservoir ◽  
Point Sources ◽  
Water Reservoirs ◽  
Discrete Time Delay ◽  
Mixing Problem

Pollution of sub-surface water reservoirs mainly rivers and streams through contaminated water point sources (CWPS) was studied. The objective was to formulate a discrete time delay mathematical model which describes the dynamics of reservoir pollution using mixing-problem processes that involve single species contaminants such as nitrates, phosphorous and detergents. The concentration &nbsp;of pollutants was expressed as a function of the inflow and outflow rates using the principle for the conservation of mass. Systems of ODEs generated from principles of mixing problems were refined into a system of DDEs so that the concentration of pollutant leaving the reservoir at time would be determined at some earlier instant, for the delay. The formulated model is a mathematical discrete time delay model which would be used to describe the dynamics of sub-surface water reservoir pollution. The results from the validation of the model were analyzed &nbsp;&nbsp;to determine how time delays in the mixing processes affect the rate of particle movement in water reservoirs.

scholarly journals Surface Water Microbial Community Response to the Biocide 2,2-Dibromo-3-Nitrilopropionamide, Used in Unconventional Oil and Gas Extraction

2019 ◽  
Vol 85 (21) ◽  
Author(s):  
Maria Fernanda Campa ◽  
Stephen M. Techtmann ◽  
Mallory P. Ladd ◽  
Jun Yan ◽  
Megan Patterson ◽  
...  
Keyword(s):  
Microbial Community ◽  
Surface Water ◽  
Microbial Communities ◽  
Oil And Gas ◽  
Community Response ◽  
Rrna Gene ◽  
Unconventional Oil ◽  
Gene Copies ◽  
Unconventional Oil And Gas ◽  
By Products

ABSTRACT Production of unconventional oil and gas continues to rise, but the effects of high-density hydraulic fracturing (HF) activity near aquatic ecosystems are not fully understood. A commonly used biocide in HF, 2,2-dibromo-3-nitrilopropionamide (DBNPA), was studied in microcosms of HF-impacted (HF+) versus HF-unimpacted (HF−) surface water streams to (i) compare the microbial community response, (ii) investigate DBNPA degradation products based on past HF exposure, and (iii) compare the microbial community response differences and similarities between the HF biocides DBNPA and glutaraldehyde. The microbial community responded to DBNPA differently in HF-impacted versus HF-unimpacted microcosms in terms of the number of 16S rRNA gene copies quantified, alpha and beta diversity, and differential abundance analyses of microbial community composition through time. The differences in microbial community changes affected degradation dynamics. HF-impacted microbial communities were more sensitive to DBNPA, causing the biocide and by-products of the degradation to persist for longer than in HF-unimpacted microcosms. A total of 17 DBNPA by-products were detected, many of them not widely known as DBNPA by-products. Many of the brominated by-products detected that are believed to be uncharacterized may pose environmental and health impacts. Similar taxa were able to tolerate glutaraldehyde and DBNPA; however, DBNPA was not as effective for microbial control, as indicated by a smaller overall decrease of 16S rRNA gene copies/ml after exposure to the biocide, and a more diverse set of taxa was able to tolerate it. These findings suggest that past HF activity in streams can affect the microbial community response to environmental perturbation such as that caused by the biocide DBNPA. IMPORTANCE Unconventional oil and gas activity can affect pH, total organic carbon, and microbial communities in surface water, altering their ability to respond to new environmental and/or anthropogenic perturbations. These findings demonstrate that 2,2-dibromo-3-nitrilopropionamide (DBNPA), a common hydraulic fracturing (HF) biocide, affects microbial communities differently as a consequence of past HF exposure, persisting longer in HF-impacted (HF+) waters. These findings also demonstrate that DBNPA has low efficacy in environmental microbial communities regardless of HF impact. These findings are of interest, as understanding microbial responses is key for formulating remediation strategies in unconventional oil and gas (UOG)-impacted environments. Moreover, some DBNPA degradation by-products are even more toxic and recalcitrant than DBNPA itself, and this work identifies novel brominated degradation by-products formed.

scholarly journals Quantifying Focused Groundwater Recharge Induced by Irrigation Surface Water Reservoirs in Crystalline Basement Areas for Complementary Irrigation

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2880
Author(s):  
Apolline Bambara ◽  
Philippe Orban ◽  
Issoufou Ouedraogo ◽  
Eric Hallot ◽  
Francis Guyon ◽  
...  
Keyword(s):  
Surface Water ◽  
Groundwater Recharge ◽  
Large Diameter ◽  
Spatiotemporal Analysis ◽  
Sub Saharan Africa ◽  
Water Reservoirs ◽  
Water Shortages ◽  
Physico Chemical ◽  
Drying Up ◽  
Sub Saharan

Through the practice of irrigation, surface water reservoirs (SWRs) contribute to the socio-economic development and food production activities of populations in Sub-Saharan Africa (SSA). However, they tend to dry up prematurely. One solution to circumvent these irrigation water shortages is to ensure their conjunctive use with groundwater. The objective of this study is to better understand the contribution of SWRs to groundwater recharge and to determine if groundwater may be considered as a complementary local resource for irrigation. The study was carried out on two watersheds in Burkina Faso, Kierma and Mogtedo. The spatiotemporal analysis of piezometric and SWRs level records coupled with physico-chemical analyses of water was used to characterize exchanges between SWRs and groundwater. The regional groundwater recharge at the scale of the watersheds was assessed. At the SWRs scale, a water balance methodology was developed and used to estimate focused recharge. The results show that SWRs interact almost continuously with groundwater and contribute focused recharge. The magnitude of this recharge is a function of the geological context and the sediment texture of the SWRs. It is estimated at 5 mm/day in Kierma and 4 mm/day in Mogtédo. These values are higher than the natural recharge estimated at 0.2 mm/day in Kierma and 0.1 mm/day in Mogtédo. Additionally, the values of hydraulic conductivity are between 0.01 and 2 m/day in Kierma and between 1 × 10−4 and 0.2 m/day in Mogtédo. These conductivities could allow pumping in large-diameter hand-dug wells with a significant yield between 0.5 and 120 m3/day in Kierma and between 0 and 10 m3/day in Mogtédo to palliate the early drying up of the SWRs.

Effects of Impervious Cover on the Surface Water Quality and Aquatic Ecosystem of the Kyeongan Stream in South Korea

2012 ◽  
Vol 84 (8) ◽  
pp. 635-645 ◽  
Author(s):  
Bum-Yeon Lee ◽  
Shin-Jeong Park ◽  
Ma. Cristina Paule ◽  
Woosong Jun ◽  
Chang-Hee Lee
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
South Korea ◽  
Aquatic Ecosystem ◽  
Surface Water Quality ◽  
Impervious Cover

Assessment of the geometry and volumes of small surface water reservoirs by remote sensing in a semi-arid region with high reservoir density

2019 ◽  
Vol 64 (1) ◽  
pp. 66-79 ◽  
Author(s):  
Bruno Pereira ◽  
Pedro Medeiros ◽  
Till Francke ◽  
Geraldo Ramalho ◽  
Saskia Foerster ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Surface Water ◽  
Arid Region ◽  
Water Reservoirs ◽  
Small Surface ◽  
Semi Arid Region ◽  
Semi Arid
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