Progress of Optical Biosensors for Analysis of Pathogens and Organic Pollutants in Water since 2015

2021 ◽  
Author(s):  
Bo Liu ◽  
Xing Song ◽  
Weiyun Lin ◽  
Yan Zhang ◽  
Bing Chen ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Pollutants ◽  
Emerging Contaminants ◽  
Biological Response ◽  
High Sensitivity ◽  
Optical Biosensor ◽  
Accurate Analysis ◽  
Optical Biosensing ◽  
Optical Signals ◽  
Increasing Demand

Water contamination by pathogens and organic pollutants is one of the major environmental problems that risk human health. Climate change with extreme weather can promote their prevalence in waters. Environmental monitoring of these pollutants in a fast, continuous, and accurate manner is of increasing demand, especially under the climate change context, but is challenged by their ubiquity and trace concentrations. Optical biosensing is one of the desired solutions owing to its rapid and accurate detection with high sensitivity. Principally, an optical biosensor recognizes these bioactive toxins and contaminants by tailored bioreceptors (e.g., aptamer, enzyme, and cells) and transduces the biological response to optical signals. Research efforts have been made on tailoring bioreceptors and enhancing signal transducing by nanoparticles. This study comprehensively reviewed the mechanisms of optical biosensing and the recent development of bioreceptors and nanomaterials on the enhancement for the rapid, easy, and accurate analysis of emerging contaminants in water. The advantages and challenges on sensitivity, selectivity, and durability of biosensors were discussed along with the opportunities and development strategies.

Climate change refugia: landscape, stand and tree-scale microclimates in epiphyte community composition

2021 ◽  
Vol 53 (1) ◽  
pp. 135-148
Author(s):  
Christopher J. Ellis ◽  
Sally Eaton
Keyword(s):  
Climate Change ◽  
Community Composition ◽  
Large Scale ◽  
Biological Response ◽  
Tree Age ◽  
Local Effects ◽  
Vulnerability To Climate Change ◽  
Or Gene ◽  
Water Holding ◽  
Epiphyte Community

AbstractThere is growing evidence that species and communities are responding to, and will continue to be affected by, climate change. For species at risk, vulnerability can be reduced by ensuring that their habitat is extensive, connected and provides opportunities for dispersal and/or gene flow, facilitating a biological response through migration or adaptation. For woodland epiphytes, vulnerability might also be reduced by ensuring sufficient habitat heterogeneity, so that microhabitats provide suitable local microclimates, even as the larger scale climate continues to change (i.e. microrefugia). This study used fuzzy set ordination to compare bryophyte and lichen epiphyte community composition to a large-scale gradient from an oceanic to a relatively more continental macroclimate. The residuals from this relationship identified microhabitats in which species composition reflected a climate that was more oceanic or more continental than would be expected given the prevailing macroclimate. Comparing these residuals to features that operate at different scales to create the microclimate (landscape, stand and tree-scale), it was possible to identify how one might engineer microrefugia into existing or new woodland, in order to reduce epiphyte vulnerability to climate change. Multimodel inference was used to identify the most important features for consideration, which included local effects such as height on the bole, angle of bole lean and bark water holding capacity, as well as tree species and tree age, and within the landscape, topographic wetness and physical exposure.

AMPLIFICATION AND PHASE CONJUGATION OF WEAK SIGNALS

1993 ◽  
Vol 02 (01) ◽  
pp. 85-115 ◽  
Author(s):  
O.V. KULAGIN ◽  
G.A. PASMANIK ◽  
A.A. SHILOV
Keyword(s):  
Theoretical Approach ◽  
Phase Conjugation ◽  
High Sensitivity ◽  
Optical Systems ◽  
Experimental Investigations ◽  
Weak Signals ◽  
Optical Signals ◽  
Basic Concepts

The results of the study on phase conjugation of weak optical signals with the energy of units of photons are considered. Basic concepts of a semi-classical theoretical approach to describe amplification and phase conjugation (PC) of such signals are presented. A review is given on the experimental investigations that allowed for reaching a limit (about 1 photon for a mode) sensitivity of optical systems with PC-mirrors for a large (~ 105) number of resolution elements. High-sensitivity PC-mirror optical systems are demonstrated for a variety of applications.

The role of conceptual hydrologic model calibration in climate change impact on water resources assessment

2015 ◽  
Vol 7 (1) ◽  
pp. 16-28 ◽  
Author(s):  
Andrijana Todorovic ◽  
Jasna Plavsic
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Regional Climate ◽  
High Sensitivity ◽  
Regional Climate Models ◽  
Baseline Period ◽  
Hydrologic Model ◽  
Calibration Period ◽  
Rainfall Runoff Model ◽  
Parameter Values

Assessment of climate change (CC) impact on hydrologic regime requires a calibrated rainfall-runoff model, defined by its structure and parameters. The parameter values depend, inter alia, on the calibration period. This paper investigates influence of the calibration period on parameter values, model efficiency and streamflow projections under CC. To this end, a conceptual HBV-light model of the Kolubara River catchment in Serbia is calibrated against flows observed within 5 consecutive wettest, driest, warmest and coldest years and in the complete record period. The optimised parameters reveal high sensitivity towards calibration period. Hydrologic projections under climate change are developed by employing (1) five hydrologic models with outputs of one GCM–RCM chain (Global and Regional Climate Models) and (2) one hydrologic model with five GCM–RCM outputs. Sign and magnitude of change in projected variables, compared to the corresponding values simulated over the baseline period, vary with the hydrologic model used. This variability is comparable in magnitude to variability stemming from climate models. Models calibrated over periods with similar precipitation as the projected ones may result in less uncertain projections, while warmer climate is not expected to contribute to the uncertainty in flow projections. Simulations over prolonged dry periods are expected to be uncertain.

scholarly journals The effects of climate change on persistent organic pollutants (POPs) in the North Sea

2013 ◽  
Vol 10 (5) ◽  
pp. 1525-1557
Author(s):  
K. O'Driscoll ◽  
B. Mayer ◽  
J. Su ◽  
M. Mathis
Keyword(s):  
Climate Change ◽  
Organic Pollutants ◽  
North Sea ◽  
21St Century ◽  
Persistent Organic Pollutants ◽  
Global Ocean ◽  
Open Boundary ◽  
The North ◽  
The Future ◽  
The North Sea

Abstract. The fate and cycling of two selected legacy persistent organic pollutants (POPs), PCB 153 and γ-HCH, in the North Sea in the 21st century have been modelled with combined hydrodynamic and fate and transport ocean models. To investigate the impact of climate variability on POPs in the North Sea in the 21st century, future scenario model runs for three 10 yr periods to the year 2100 using plausible levels of both in situ concentrations and atmospheric, river and open boundary inputs are performed. Since estimates of future concentration levels of POPs in the atmosphere, oceans and rivers are not available, our approach was to reutilise 2005 values in the atmosphere, rivers and at the open ocean boundaries for every year of the simulations. In this way, we attribute differences between the three 10 yr simulations to climate change only. For the HAMSOM and atmospheric forcing, results of the IPCC A1B (SRES) 21st century scenario are utilised, where surface forcing is provided by the REMO downscaling of the ECHAM5 global atmospheric model, and open boundary conditions are provided by the MPIOM global ocean model. Dry gas deposition and volatilisation of γ-HCH increase in the future relative to the present. In the water column, total mass of γ-HCH and PCB 153 remain fairly steady in all three runs. In sediment, γ-HCH increases in the future runs, relative to the present, while PCB 153 in sediment decreases exponentially in all three runs, but even faster in the future, both of which are the result of climate change. Annual net sinks exceed sources at the ends of all periods.

scholarly journals Machine Learning Speeding Up the Development of Portfolio of New Crop Varieties to Adapt to and Mitigate Climate Change

2021 ◽  
Author(s):  
Abdallah Bari ◽  
Hassan Ouabbou ◽  
abderrazek Jilal ◽  
Hamid Khazaei ◽  
Fred Stoddard ◽  
...  
Keyword(s):  
Climate Change ◽  
Machine Learning ◽  
Crop Varieties ◽  
Short Period ◽  
Speed Up ◽  
Increasing Demand ◽  
Mitigate Climate Change ◽  
High Yielding Varieties ◽  
New Crop ◽  
Adaptation And Mitigation

Climate change poses serious challenges to achieving food security in a time of a need to produce more food to keep up with the worlds increasing demand for food. There is an urgent need to speed up the development of new high yielding varieties with traits of adaptation and mitigation to climate change. Mathematical approaches, including ML approaches, have been used to search for such traits, leading to unprecedented results as some of the traits, including heat traits that have been long sought-for, have been found within a short period of time.

scholarly journals Vulnerability analysis of capture fisheries to climate change based on the Province Scale (exposure and sensitivity analysis)

2021 ◽  
Vol 869 (1) ◽  
pp. 012016
Author(s):  
V Mandhalika ◽  
A B Sambah ◽  
D O Sutjipto ◽  
F Iranawati ◽  
M A Z Fuad ◽  
...  
Keyword(s):  
Climate Change ◽  
High Sensitivity ◽  
Final Analysis ◽  
Vulnerability Analysis ◽  
Exposure Analysis ◽  
Sst Variability ◽  
Vulnerability To Climate Change ◽  
Important Input ◽  
Recorded Data ◽  
Very High

Abstract Fisheries has a major contribution for the Indonesian economy both on a local and national scale. However, the phenomenon of climate change can threaten the sustainability of this sector. Therefore, a scientific approach is needed to determine the level of risk and adaptation strategies for fisheries, one of which is through vulnerability analysis. Vulnerability is the final analysis resulted from the analysis of sensitivity and exposure. Both of these analyses are important to determine the parameters that will affect the value of the fishery vulnerability to climate change. This research is focused on sensitivity and exposure analysis with the coverage limit is the province area to determine the sensitivity and exposure index that exists in the study area. The result will be important input in further research for the vulnerability of capture fisheries to climate change. Three provinces in Indonesia were selected through purposive sampling method. The source of data for indices variables were using recorded data in 2009-2020 from relevant sources. Result described that SST variability in the three provinces has the same pattern. In the exposure analysis, the SST is linked to the catch resulting in different exposure statuses in each province. It also illustrated those areas with a very high number of fishermen and catches will have very high sensitivity. The research will support in the sustainable management of capture fish at the province scale.

scholarly journals A dual electro-optical biosensor based on Chlamydomonas reinhardtii immobilised on paper-based nanomodified screen-printed electrodes for herbicide monitoring

2021 ◽  
Author(s):  
Amina Antonacci ◽  
Raouia Attaallah ◽  
Fabiana Arduini ◽  
Aziz Amine ◽  
Maria Teresa Giardi ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
High Sensitivity ◽  
Optical Biosensor ◽  
Whole Cells ◽  
Screen Printed Electrodes ◽  
And Storage ◽  
High Repeatability ◽  
High Sensitivity Detection ◽  
Screen Printed

Abstract The indiscriminate use of herbicides in agriculture contributes to soil and water pollution, with important endangering consequences on the ecosystems. Among the available analytical systems, algal biosensors have demonstrated to be valid tools thanks to their high sensitivity, cost-effectiveness, and eco-design. Herein, we report the development of a dual electro-optical biosensor for herbicide monitoring, based on Chlamydomonas reinhardtii whole cells immobilised on paper-based screen-printed electrodes modified with carbon black nanomaterials. To this aim, a systematic study was performed for the selection and characterisation of a collection among 28 different genetic variants of the alga with difference response behaviour towards diverse herbicide classes. Thus, CC125 strain was exploited as case study for the study of the analytical parameters. The biosensor was tested in standard solutions and real samples, providing high sensitivity (detection limit in the pico/nanomolar), high repeatability (RSD of 5% with n = 100), long lasting working (10 h) and storage stability (3 weeks), any interference in the presence of heavy metals and insecticides, and low matrix effect in drinking water and moderate effect in surface one.

What can we Predict Before it's Implanted?

1985 ◽  
Vol 55 ◽  
Author(s):  
Donald F. Gibbons
Keyword(s):  
Biological Response ◽  
High Sensitivity ◽  
Biological Pathways ◽  
Surface Topology ◽  
Dystrophic Calcification ◽  
Vitro Assay ◽  
In Vivo Assays ◽  
Tissue Interface

ABSTRACTThe material factors which relate to the degradation and/or leaching of ions or molecules are described and the possible biological pathways which they may activate are described, i.e. cytotoxic, immune, tumor and nonspecific inflammatory response. Cytotoxicity is the only biological response which may be measured with high sensitivity by an in vitro assay prior to implantation. All other biological pathways require some degree of in vivo involvement. Three examples of biological response to material factors associated with devices which require evaluation by in vivo assays are discussed, namely: surface topology (texture), mechanically induced factors at the device/tissue interface caused by differences in compliance, and dystrophic calcification in connective tissue and vascular devices.

scholarly journals Label-Free Optical Biosensing Using Low-Cost Electrospun Polymeric Nanofibers

Chemosensors ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 119
Author(s):  
Paula Martínez-Pérez ◽  
Salvador Ponce-Alcántara ◽  
Nieves Murillo ◽  
Ana Pérez-Márquez ◽  
Jon Maudes ◽  
...  
Keyword(s):  
Real Time ◽  
Large Scale ◽  
High Surface ◽  
Protein A ◽  
Volume Ratio ◽  
Polyamide 6 ◽  
Optical Biosensor ◽  
Label Free ◽  
Electrospinning Technique ◽  
Optical Biosensing

Polymeric nanofiber matrices are promising structures to develop biosensing devices due to their easy and affordable large-scale fabrication and their high surface-to-volume ratio. In this work, the suitability of a polyamide 6 nanofiber matrix for the development of a label-free and real-time Fabry–Pérot cavity-based optical biosensor was studied. For such aim, in-flow biofunctionalization of nanofibers with antibodies, bound through a protein A/G layer, and specific biodetection of 10 µg/mL bovine serum albumin (BSA) were carried out. Both processes were successfully monitored via reflectivity measurements in real-time without labels and their reproducibility was demonstrated when different polymeric nanofiber matrices from the same electrospinning batch were employed as transducers. These results demonstrate not only the suitability of correctly biofunctionalized polyamide 6 nanofiber matrices to be employed for real-time and label-free specific biodetection purposes, but also the potential of electrospinning technique to create affordable and easy-to-fabricate at large scale optical transducers with a reproducible performance.

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