scholarly journals Insights into Bioindicator Redundancy for Monitoring Water Quality based on Functional Units of Periphytic Protozoan Communities in Marine Ecosystems

2021 ◽  
Author(s):  
Syed Shabi Ul Hassan Kazmi ◽  
Uroosa Uroosa ◽  
Alan Warren ◽  
Guangjian Xu ◽  
Henglong Xu
Keyword(s):  
Water Quality ◽  
Relative Abundance ◽  
Species Abundance ◽  
Oxygen Demand ◽  
Functional Redundancy ◽  
Baseline Survey ◽  
High Signal ◽  
Biological Traits ◽  
Signal To Noise ◽  
Functional Units

Abstract Although periphytic protozoan communities have long been used for the bioassessment of water quality, their utility is hampered by functional redundancy leading to high “signal to noise” ratios. In this study, a 1-year baseline survey of periphytic protozoan communities was carried out in coastal waters of Yellow sea, northern China, in order to determine redundancy levels in conditions of differing water quality. Samples were collected at four sampling sites along a pollution gradient. Environmental variables such as salinity, chemical oxygen demand (COD), and concentrations of dissolved oxygen (DO), soluble reactive phosphates (SRP), ammonium nitrogen (NH4-N) and nitrate nitrogen (NO3-N) were measured to compare with biotic factors. A total of 53 functional units (FUs) were identified from 144 observed protozoan species based on four biological traits, i.e., feeding type, body size, movement type and source of food supply. For reducing the “signal to noise” ratios of species-abundance/biomass data, the peeling procedure was used to identify the bioindicator redundancy levels based on these FUs. Three consecutive subsets of response units (RU1–RU3) with correlation coefficients >0.75 of the full FU dataset were identified, comprising 12, 21 and 9 FUs, respectively. Algivores and bacterivores were dominant in RU1 and RU2 among the polluted sites, whereas raptors were dominant in RU3 at the unpolluted site. In terms of relative abundance, RU1 was the primary contributor to the protozoan communities during the 1-year cycle and its relative abundance increased with increasing pollution, whereas RU2 and RU3, with complementary temporal distributions, generally decreased with increasing pollution. Ordinations based on boot-strapped average analyses revealed a significant variation in functional pattern of all three RUs among the four sampling sites. Biological-environmental match analysis demonstrated that the variability was driven by the increasing concentrations of nutrients (e.g., NH4-N, NO3-N and PO4-P) and decreasing concentrations of DO (P<0.05). Based on these findings, it is suggested that there were high levels of functional redundancy among periphytic protozoan communities used as bioindicators of marine water quality.

scholarly journals Insights into bioassessment of water quality status using functional units of protozoan periphytons in marine ecosystems

2021 ◽  
Author(s):  
Syed Shabi Ul Hassan Kazmi ◽  
Uroosa Uroosa ◽  
Henglong Xu
Keyword(s):  
Water Quality ◽  
Anthropogenic Impacts ◽  
Oxygen Demand ◽  
Marine Ecosystems ◽  
Baseline Survey ◽  
Biological Traits ◽  
Ecological Features ◽  
Water Quality Status ◽  
Functional Units ◽  
Quality Status

Abstract Protozoan periphytons with their ecological features are considered as a robust bioindicator for bioassessment of both environmental stress and anthropogenic impacts in aquatic ecosystems. Keeping in view the ability of protozoan fauna for discriminating water quality status, a 1-year baseline survey was conducted using glass slides as an artificial substratum in coastal waters of Yellow sea, northern China. Four sampling sites (A–D) were selected from a clean area to a polluted station, and samples were collected monthly at a depth of 1 m. Environmental variables such as salinity, chemical oxygen demand (COD), dissolved oxygen (DO), soluble reactive phosphates (SRP), ammonium nitrogen (NH4-N) and nitrate nitrogen (NO3-N) were measured synchronically to compare with biotic factors. From a total of 144 identified protozoan species, 53 functional units (FUs) were proposed based on four biological traits: feeding type, resource of food supply, body size and movement type. These FUs represented a clear variability in spatial distribution among four study sites. The relative abundances of the sessile colonial bacterivores (e.g., BOS5s) showed an increasing trend from sites A to D. Multivariate analysis revealed that the patterns of the protozoan FUs showed a significant variation among four sampling sites, and were driven by the increasing levels of nutrients (e.g., NH4-N) and decreasing ranks of DO (P < 0.05). The bacterivorous FUs (e.g., BOS5s and BIS3v) were significantly positively related to NH4-N, while the vagile algivorous FUs (e.g., AIS8v, AOS3v, AOS6v) and sessile predators (e.g., RIS4s) were significantly positively correlated with transparency. These findings suggested that FUs of protozoan periphytons may be used as a useful bioindicators of water quality status in marine ecosystems.

scholarly journals The butterfly community assemblage of Mowire Quarry Site in the forest agroecological zone of Ghana: Response of indicator biodiversity to ongoing quarry operations.

2020 ◽  
Author(s):  
Sampson Addae ◽  
Sampson Addae ◽  
Michael Osae ◽  
Danilo Harms ◽  
Jones Quartey ◽  
...  
Keyword(s):  
Species Richness ◽  
Environmental Impact ◽  
Relative Abundance ◽  
Negative Impact ◽  
Species Abundance ◽  
Habitat Destruction ◽  
Baseline Survey ◽  
Community Assemblage ◽  
Western Africa ◽  
Agroecological Zone

Quarry operations cause serious environmental impact on invertebrate communities and contribute negatively to habitat destruction and the species they promote but very little is still known about the response of butterflies to such disturbances in western Africa. The current study provides data from a baseline survey of butterflies at Mowire quarry site in the agroecological zone of Ghana and investigates the effects of ongoing quarry operations on butterfly diversity. Specifically quarry operations were assessed on species abundance and richness. A total of 417 individual butterflies belonging to 67 species from 5 families was recorded in three zones. High relative abundance in the Eastern Zone (EZ) (N = 329) and high species richness (S = 55) may be due to increased flowering plants diversity which contain sweet nectar which attracts and support rich butterfly abundance. Low species richness (S = 22) and relative abundance (N= 41) in the Western Zone (WZ), and Northern Zone (NZ) (S = 21) and low relative abundance (N= 47), was corroborated with low plant diversity. Our results shows that, the EZ received less negative impact from the quarry operations but the operations negatively affected WZ and NZ. More generally our study indicates that state institutions should ensure mandatory environmental impact assessment reports from the quarry companies.

A compact guided-wave EMAT with pulsed electromagnet for ferromagnetic tube inspection

2020 ◽  
Vol 64 (1-4) ◽  
pp. 951-958
Author(s):  
Tianhao Liu ◽  
Yu Jin ◽  
Cuixiang Pei ◽  
Jie Han ◽  
Zhenmao Chen
Keyword(s):  
Power Plants ◽  
Signal To Noise Ratio ◽  
Small Diameter ◽  
Performance Testing ◽  
Guided Wave ◽  
High Signal ◽  
Receiver Coil ◽  
Signal To Noise ◽  
Corrosion Defects

Small-diameter tubes that are widely used in petroleum industries and power plants experience corrosion during long-term services. In this paper, a compact inserted guided-wave EMAT with a pulsed electromagnet is proposed for small-diameter tube inspection. The proposed transducer is noncontact, compact with high signal-to-noise ratio and unattractive to ferromagnetic tubes. The proposed EMAT is designed with coils-only configuration, which consists of a pulsed electromagnet and a meander pulser/receiver coil. Both the numerical simulation and experimental results validate its feasibility on generating and receiving L(0,2) mode guided wave. The parameters for driving the proposed EMAT are optimized by performance testing. Finally, feasibility on quantification evaluation for corrosion defects was verified by experiments.

Computationally Assisted Design of High Signal-to-Noise Photoinduced Electron Transfer-Based Voltage-Sensitive Dyes

2020 ◽  
Author(s):  
Rishikesh Kulkarni ◽  
Anneliese Gest ◽  
Chun Kei Lam ◽  
Benjamin Raliski ◽  
Feroz James ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Dft Calculations ◽  
Photoinduced Electron Transfer ◽  
Density Functional ◽  
Embryonic Stem ◽  
High Sensitivity ◽  
Md Simulations ◽  
High Signal ◽  
Signal To Noise ◽  
Green Fluorescent

<p>High signal-to-noise optical voltage indicators will enable simultaneous interrogation of membrane potential in large ensembles of neurons. However, design principles for voltage sensors with high sensitivity and brightness remain elusive, limiting the applicability of voltage imaging. In this paper, we use molecular dynamics (MD) simulations and density functional theory (DFT) calculations to guide the design of a bright and sensitive green-fluorescent voltage-sensitive fluorophore, or VoltageFluor (VF dye), that uses photoinduced electron transfer (PeT) as a voltage-sensing mechanism. MD simulations predict an 11% increase in sensitivity due to membrane orientation, while DFT calculations predict an increase in fluorescence quantum yield, but a decrease in sensitivity due to a decrease in rate of PeT. We confirm these predictions by synthesizing a new VF dye and demonstrating that it displays the expected improvements by doubling the brightness and retaining similar sensitivity to prior VF dyes. Combining theoretical predictions and experimental validation has resulted in the synthesis of the highest signal-to-noise green VF dye to date. We use this new voltage indicator to monitor the electrophysiological maturation of human embryonic stem cell-derived medium spiny neurons. </p>

Spatio-temporal Variations in Water Quality Parameter Trends in River Waters

2018 ◽  
Vol 69 (10) ◽  
pp. 2940-2952 ◽  
Author(s):  
Martina Zelenakova ◽  
Pavol Purcz ◽  
Radu Daniel Pintilii ◽  
Peter Blistan ◽  
Petr Hlustik ◽  
...  
Keyword(s):  
Water Quality ◽  
Chemical Oxygen Demand ◽  
Quality Indicators ◽  
Water Resource Management ◽  
Oxygen Demand ◽  
Temporal Variations ◽  
Water Quality Parameter ◽  
Agricultural Activity ◽  
Water Quality Indicators ◽  
Nitrite Nitrogen

Evaluating trends in water quality indicators is a crucial issue in integrated water resource management in any country. In this study eight chemical and physical water quality indicators were analysed in seven river profiles in the River Laborec in eastern Slovakia. The analysed water quality parameters were biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), pH, temperature (t), ammonium nitrogen (NH4+-N), nitrite nitrogen (NO2--N), nitrate nitrogen (NO3--N), and total phosphorus (TP). Data from the monitored indicators were provided by the Ko�ice branch of the Slovakian Water Management Company, over a period of 15 years from 1999 to 2013. Mann�Kendall non-parametric statistical test was used for the trend analysis. Biochemical and chemical oxygen demand, ammonium and nitrite nitrogen content exhibit decreasing trends in the River Laborec. Decreasing agricultural activity in the area has had a significant impact on the trends in these parameters. However, NO2--N was the significant parameter of water quality because it mostly exceeds the limit value set in Slovak legislation, Regulation No. 269/2010 Coll. In addition, water temperature revealed an increasing trend which could be caused by global increase in air temperature. These results indicate that human activity significantly impacts the water quality.

Applying Probabilistic Water Quality Standards in River Basin Water Quality Optimization Models

1974 ◽  
Vol 9 (1) ◽  
pp. 25-29
Author(s):  
M. B. Bayer
Keyword(s):  
Water Quality ◽  
River Basin ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Minimum Cost ◽  
Water Quality Standards ◽  
Quality Optimization ◽  
Basin Water ◽  
Do Concentration ◽  
Water Quality Models

Abstract This paper describes a method of applying probabilistic DO (dissolved oxygen) and BOD (biochemical oxygen demand) standards in river basin water quality models. Maximum likelihood estimators for the DO and BOD concentrations variances for each reach are used to obtain a lower bound for BOD so that the probability of violating specified DO and BOD standards is less than Θ per cent in any reach. These boundary values for DO and BOD concentrations are incorporated into a nonlinear water quality optimization model for finding the minimum cost set of wastewater treatment plant efficiencies required to meet DO and BOD standards. The method also provides the minimum DO concentration and the maximum BOD concentration which may be expected to occur 1-Θ of the time for any reach.

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