Controls of bio-modulated flocculation on the fate of microplastic pollution in river-estuary transition zones

2021 ◽  
Author(s):  
Freija Mendrik ◽  
Roberto Fernández ◽  
Christopher Hackney ◽  
Catherine Waller ◽  
Robert Dorrell ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Particle Density ◽  
River Estuary ◽  
Global Scale ◽  
Mekong River ◽  
Biological Interactions ◽  
Plastic Pollution ◽  
High Accumulation ◽  
Vertical Velocity Profile ◽  
The Impact

<p>Plastic fragments floating on the surface of oceans represent less than 1% of plastic pollution entering these environments annually, with the fate of the remaining plastics largely unknown. There are several removal mechanisms that have been suggested for microplastics (<5mm) including ingestion by biota, biofouling and/or aggregation with organic material leading to flocculation and a change in particle density that can impact trajectory and fate of the material. Furthermore, despite the widespread recognition that rivers dominate the global flux of plastics to the ocean, there is a key knowledge gap regarding the behaviour of microplastics in transport and its pathways from rivers into the coastal zone, especially in regards to how biofilm formation and aggregation influence particle fate. This prevents progress in understanding microplastic dynamics and identifying zones of high accumulation, as well as curtailing the evolution of effective mitigation and policy measures. To predict transport, fate and biological interactions of microplastics in aquatic environments at a global scale, the factors that control these processes must be identified and understood.</p><p>A laboratory settling experiment was therefore conducted to recognise how different factors, including salinity, suspended sediment and biofilm formation influence microplastic particle settling velocities, and thus transport. The results presented herein explore the role of biofilms on the generation of microplastic flocs and the impact on buoyancy and settling velocities. Six different polymers were tested and compared including fragments and fibres. Settling velocities were then combined with field flow data from the Mekong River, one of the top global contributors to marine plastic pollution, allowing predictions of areas of microplastic fallout and hotspots. The results also highlight potential areas of ecological risk related to the dispersal and distribution of microplastics across the river-delta-coast system including the ecologically important Tonle Sap Lake. Future work involves further aligned fieldwork within the Mekong River that details the particulate flux and transport of microplastics throughout the vertical velocity profile.</p>

From Fear to Hope: The inspiring journey of an 11-year-old Environmental Activist

2020 ◽  
Author(s):  
Florence Halstead ◽  
Lucie Parsons ◽  
Katie Parsons
Keyword(s):  
Climate Change ◽  
Science Communication ◽  
State Level ◽  
Global Scale ◽  
Ecological Crisis ◽  
Future Climate Change ◽  
Environmental Action ◽  
Plastic Pollution ◽  
Greenhouse Gasses ◽  
The Impact

<p>"When I first became aware of the destruction of the world through climate change, I felt very upset and angry, but also a little worried.  What was going to happen to my world? And what was everyone going to do about it, including me?” (Parsons, 2019).</p><p>The Earth is currently undergoing a sixth global scale ecological crisis. The available science almost unanimously positions human activity at the heart of the cause of this crisis, with anthropogenic emissions of greenhouse gasses, pollution, land degradation and deforestation, all contributing. Recent IPCC reporting has demonstrated a need to curb global warming at 1.5 degrees above the pre-industrial baseline and have highlighted a range of likely impacts of Climate Change should no action be taken, particularly in relation to reducing greenhouse gas emissions to net zero by 2050. Despite this need, policy-based action at a nation state level is largely lacking, with recent talks at COP25 failing to reach agreements. However, a significant global youth movement is now underway, with children and young people taking it upon themselves to highlight a need for climate and environmental action, calling for others to follow. Greta Thunberg and the Fridays For Future (#FFF) movement now regularly appears in mainstream media, highlighting the issues of Climate Change with an emotive narrative centred on the impact of future climate change on today’s children and their environments.</p><p>Whist there is growing literature that explores Youth Activism, to our knowledge, there is no investigation that has followed the emotional journey of a child whom has chosen to take environmental action. Here, we present Lucie Parsons, an 11-year old girl who, after watching BBC’s Blue Planet II back in 2017 and seeing the devastation plastic pollution was having on the marine environment and its wildlife, decided to take action and be a champion for positive environmental change. Since then, Lucie has spoken at international conferences, conducted her own research in her primary school, organised regional litter picks, and has become an Ambassador for the national charities iWill and Kids Against Plastic; amongst many other things. As her activism has gained momentum and as she has become more aware of wider environmental issues, her focus on plastic pollution has broadened to include the current climate crisis and environmental degradation as a whole. We will present the highs and lows of Lucie’s Environmental Activism and the role that emotion has played in her journey thus far; as well as what she believes to be the achievements in her own science communication and what you as scientists can do to help her in her fight against environmental and climatic change.</p><p> </p>

Controls on microplastic flux mechanisms in a large river

2020 ◽  
Author(s):  
Freija Mendrik ◽  
Daniel Parsons ◽  
Christopher Hackney ◽  
Cath Waller ◽  
Vivien Cumming ◽  
...  
Keyword(s):  
Mekong Delta ◽  
Large River ◽  
Field Investigation ◽  
Population Increase ◽  
Plastic Pollution ◽  
Source To Sink ◽  
Tonle Sap ◽  
Vertical Velocity Profile ◽  
The Impact

<p>The majority of marine plastic pollution originates from land-based sources with the dominant transport agent being riverine. Despite many of the potential ecotoxicological consequences of plastics being well known, research has only just recently begun to explore the source to sink dynamics of plastics in the environment. Despite the widespread recognition that rivers dominate the global flux of plastics to the ocean, there is a key knowledge gap regarding the nature of the flux, the behaviour of microplastics (<5mm) in transport and its pathways from rivers into the ocean. Additionally, little is presently known about the role of biota in the transport of microplastics through processes such as biofilm formation and how this influences microplastic fate. This prevents progress in understanding microplastic fate and hotspot formation, as well as curtailing the evolution of effective mitigation and policy measures.</p><p> </p><p>As part of the National Geographic Rivers of Plastic project, a combined-laboratory and field investigation was conducted. Fieldwork was undertaken in the Mekong River, one of the top global contributors to marine plastic pollution with an estimated 37,000 tonnes of plastic being discharged from the Mekong Delta each year. This flux is set to grow significantly in accordance with the projected population increase in the basin. The results presented herein outline a suite of laboratory experiments that explore the role of biofilms on the generation of microplastic flocs and the impact on buoyancy and settling velocities. Aligned fieldwork details the particulate flux and transport of microplastic, throughout the vertical velocity profile, across the river-delta-coast system, including the Tonle Sap Lake. The results also highlight potential areas of highest ecological risk related to the dispersal and distribution of microplastics. Finally, pilot data on the levels of microplastics within fish from the Mekong system are also quantified to explore the potential impact of biological uptake on the fate and sinks of plastics within the system.</p>

Confocal and SEM imaging to demonstrate food pathogen- biofilm biocontrol by pyocyanin from Pseudomonas aeruginosa BTRY1

2016 ◽  
Vol 6 (01) ◽  
pp. 5218
Author(s):  
Laxmi Mohandas ◽  
Anju T. R. ◽  
Sarita G. Bhat*
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Antibiofilm Activity ◽  
Opportunistic Pathogens ◽  
Redox Active ◽  
Sem Imaging ◽  
The Impact

An assortment of redox-active phenazine compounds like pyocyanin with their characteristic blue-green colour are synthesized by Pseudomonas aeruginosa, Gram-negative opportunistic pathogens, which are also considered one of the most commercially valuable microorganisms. In this study, pyocyanin from Pseudomonas aeruginosa BTRY1 from food sample was assessed for its antibiofilm activity by micro titer plate assay against strong biofilm producers belonging to the genera Bacillus, Staphylococcus, Brevibacterium and Micrococcus. Pyocyanin inhibited biofilm activity in very minute concentrations. This was also confirmed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Both SEM and CLSM helped to visualize the biocontrol of biofilm formation by eight pathogens. The imaging and quantification by CLSM also established the impact of pyocyanin on biofilm-biocontrol mainly in the food industry.

scholarly journals The Impact of Dental Implant Surface Modifications on Osseointegration and Biofilm Formation

2021 ◽  
Vol 10 (8) ◽  
pp. 1641
Author(s):  
Stefanie Kligman ◽  
Zhi Ren ◽  
Chun-Hsi Chung ◽  
Michael Angelo Perillo ◽  
Yu-Cheng Chang ◽  
...  
Keyword(s):  
Dental Implant ◽  
Biofilm Formation ◽  
Bacterial Colonization ◽  
Surface Modifications ◽  
Implant Surface ◽  
Oral Rehabilitation ◽  
Surface Design ◽  
Polyether Ether Ketone ◽  
Dental Implant Surface ◽  
The Impact

Implant surface design has evolved to meet oral rehabilitation challenges in both healthy and compromised bone. For example, to conquer the most common dental implant-related complications, peri-implantitis, and subsequent implant loss, implant surfaces have been modified to introduce desired properties to a dental implant and thus increase the implant success rate and expand their indications. Until now, a diversity of implant surface modifications, including different physical, chemical, and biological techniques, have been applied to a broad range of materials, such as titanium, zirconia, and polyether ether ketone, to achieve these goals. Ideal modifications enhance the interaction between the implant’s surface and its surrounding bone which will facilitate osseointegration while minimizing the bacterial colonization to reduce the risk of biofilm formation. This review article aims to comprehensively discuss currently available implant surface modifications commonly used in implantology in terms of their impact on osseointegration and biofilm formation, which is critical for clinicians to choose the most suitable materials to improve the success and survival of implantation.

scholarly journals Effect of Titanium Dioxide Nanoparticles on the Expression of Efflux Pump and Quorum-Sensing Genes in MDR Pseudomonas aeruginosa Isolates

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 625
Author(s):  
Fatma Y. Ahmed ◽  
Usama Farghaly Aly ◽  
Rehab Mahmoud Abd El-Baky ◽  
Nancy G. F. M. Waly
Keyword(s):  
Titanium Dioxide ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Efflux Pumps ◽  
Antibiofilm Activity ◽  
The Impact

Most of the infections caused by multi-drug resistant (MDR) P. aeruginosa strains are extremely difficult to be treated with conventional antibiotics. Biofilm formation and efflux pumps are recognized as the major antibiotic resistance mechanisms in MDR P. aeruginosa. Biofilm formation by P. aeruginosa depends mainly on the cell-to-cell communication quorum-sensing (QS) systems. Titanium dioxide nanoparticles (TDN) have been used as antimicrobial agents against several microorganisms but have not been reported as an anti-QS agent. This study aims to evaluate the impact of titanium dioxide nanoparticles (TDN) on QS and efflux pump genes expression in MDR P. aeruginosa isolates. The antimicrobial susceptibility of 25 P. aeruginosa isolates were performed by Kirby–Bauer disc diffusion. Titanium dioxide nanoparticles (TDN) were prepared by the sol gel method and characterized by different techniques (DLS, HR-TEM, XRD, and FTIR). The expression of efflux pumps in the MDR isolates was detected by the determination of MICs of different antibiotics in the presence and absence of carbonyl cyanide m-chlorophenylhydrazone (CCCP). Biofilm formation and the antibiofilm activity of TDN were determined using the tissue culture plate method. The effects of TDN on the expression of QS genes and efflux pump genes were tested using real-time polymerase chain reaction (RT-PCR). The average size of the TDNs was 64.77 nm. It was found that TDN showed a significant reduction in biofilm formation (96%) and represented superior antibacterial activity against P. aeruginosa strains in comparison to titanium dioxide powder. In addition, the use of TDN alone or in combination with antibiotics resulted in significant downregulation of the efflux pump genes (MexY, MexB, MexA) and QS-regulated genes (lasR, lasI, rhll, rhlR, pqsA, pqsR) in comparison to the untreated isolate. TDN can increase the therapeutic efficacy of traditional antibiotics by affecting efflux pump expression and quorum-sensing genes controlling biofilm production.

scholarly journals Do Microplastics Enter Our Food Chain Via Root Vegetables? A Raman Based Spectroscopic Study on Raphanus sativus

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2329
Author(s):  
Leda-Eleni Tympa ◽  
Klytaimnistra Katsara ◽  
Panagiotis N. Moschou ◽  
George Kenanakis ◽  
Vassilis M. Papadakis
Keyword(s):  
Raphanus Sativus ◽  
Acrylonitrile Butadiene Styrene ◽  
Terrestrial Ecosystems ◽  
Label Free ◽  
Plastic Pollution ◽  
Potential Threat ◽  
Safety Studies ◽  
Widespread Phenomenon ◽  
Agriculture And Food ◽  
The Impact

The outburst of plastic pollution in terrestrial ecosystems poses a potential threat to agriculture and food safety. Studies have already provided evidence for the uptake of plastic microparticles by several plant species, accompanied by numerous developmental effects, using fluorescence labelling techniques. Here, we introduce the implementation of confocal Raman spectroscopy, a label-free method, for the effective detection of microplastics (MPs) accumulation in the roots of a common edible root vegetable plant, Raphanus sativus, after treatment with acrylonitrile butadiene styrene (ABS) powder. We also demonstrate the concomitant occurrence of phenotypic defects in the polymer-treated plants. We anticipate that this work can provide new insights not only into the extent of the impact this widespread phenomenon has on crop plants but also on the methodological requirements to address it.

scholarly journals Determination of Zero Dimensional, Apparent Devolatilization Kinetics for Biomass Particles at Suspension Firing Conditions

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1018
Author(s):  
Anna Espekvist ◽  
Tian Li ◽  
Peter Glarborg ◽  
Terese Løvås ◽  
Peter Arendt Jensen
Keyword(s):  
Aspect Ratio ◽  
Particle Density ◽  
Fluid Dynamic ◽  
Particle Radius ◽  
Biomass Combustion ◽  
Least Squares Regression ◽  
Gas Temperature ◽  
Density Maximum ◽  
Parameter Ranges ◽  
The Impact

As part of the strive for a carbon neutral energy production, biomass combustion has been widely implemented in retrofitted coal burners. Modeling aids substantially in prediction of biomass flame behavior and thus in boiler chamber conditions. In this work, a simple model for devolatilization of biomass at conditions relevant for suspension firing is presented. It employs Arrhenius parameters in a single first order (SFOR) devolatilization reaction, where the effects of kinetics and heat transfer limitations are lumped together. In this way, a biomass particle can be modeled as a zero dimensional, isothermal particle, facilitating computational fluid dynamic calculations of boiler chambers. The zero dimensional model includes the effects of particle aspect ratio, particle density, maximum gas temperature, and particle radius. It is developed using the multivariate data analysis method, partial least squares regression, and is validated against a more rigorous semi-2D devolatilization model. The model has the capability to predict devolatilization time for conditions in the parameter ranges; radius (39–1569 μμm), density (700–1300 kg/m3), gas temperature (1300–1900 K), aspect ratio (1.01–8). Results show that the particle radius and gas phase temperature have a large influence on the devolatilization rate, and the aspect ratio has a comparatively smaller effect, which, however, cannot be neglected. The impact of aspect ratio levels off as it increases. The model is suitable for use as stand alone or as a submodel for biomass particle devolatilization in CFD models.

scholarly journals Applying Google Trends’ Search Popularity Indicator to Professional Cycling

2021 ◽  
pp. 152700252098832
Author(s):  
Alexander Genoe ◽  
Ronald Rousseau ◽  
Sandra Rousseau
Keyword(s):  
Fixed Effects ◽  
Global Scale ◽  
Google Trends ◽  
Panel Model ◽  
Tour De France ◽  
Country Preference ◽  
The Impact ◽  
Professional Cycling

This study uses Google Trends data to analyze the impact of the main events in the Tour de France 2019 on cyclists’ online popularity in 12 countries and at a global scale. A fixed effects panel model revealed a strong own-country preference. While online popularity increased with the duration of the Tour, race incidents strongly influenced online popularity. Besides the yellow jersey, winning a stage was more important than wearing the green, white or polka dot jersey for most regions. Still, on a global scale, young cyclists’ online popularity benefited more from wearing the white jersey than from winning a Tour stage.

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