Name: sampling, identification and characterization of microplastics release from polypropylene baby feeding bottle during daily use
Uploaded: 2021-07-24T14:45:00
Description: Watch this Scientific Journal Video about Sampling, Identification and Characterization of Microplastics Release from Polypropylene Baby Feeding Bottle during Daily Use at JoVE.com

The authors appreciate the Enterprise Ireland (grant number CF20180870) and Science Foundation Ireland (grants numbers: 20/FIP/PL/8733, 12/RC/2278_P2 and 16/IA/4462) for financial support. We also acknowledge financial support from the School of Engineering Scholarship at Trinity College Dublin and China Scholarship Council (201506210089 and 201608300005). In addition, we appreciate the professional help from Prof. Sarah Mc Cormack and technician teams (David A. McAulay, Mary O&#39;Shea, Patrick L.K. Veale, Robert Fitzpatrick and Mark Gilligan etc.) of Trinity Civil, Structural and Environmental Department and AMBER Research Centre.

1. Hot water preparation
<ol>
	<li>For all hardware that comes into contact with the samples, use clean glass made of borosilicate 3.3 to prevent any potential contamination. Thoroughly clean all the glassware. 
	Caution: Pre-existing scratches or imperfection spots on glassware can release particles during the heating and shaking process. We suggest that users check the glassware and avoid the use of the scratched glassware. Our comparison of glassware made of different glasses (such as soda-lime...

<ol>
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S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+microplastics+in+human+colectomy+specimens.">Detection of microplastics in human colectomy specimens.</a> JGH Open. , (2021).</li><li>Ragusa, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasticenta:+First+evidence+of+microplastics+in+human+placenta.">Plasticenta: First evidence of microplastics in human placenta.</a> Environment International. 146, 106274 (2021).</li><li>Schwabl, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+various+microplastics+in+human+stool:+a+prospective+case+Series.">Detection of various microplastics in human stool: a prospective case Series.</a> Annals of Internal Medicine. 171 (7), 453-457 (2019).</li><li>Sturm, M. 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M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plastic+teabags+release+billions+of+microparticles+and+nanoparticles+into+tea.">Plastic teabags release billions of microparticles and nanoparticles into tea.</a> Environmental Science &amp; Technology. 53 (21), 12300-12310 (2019).</li><li>Frias, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Standardised+protocol+for+monitoring+microplastics+in+sediments.">Standardised protocol for monitoring microplastics in sediments.</a> Deliverable 4.2. , (2018).</li><li>Li, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microplastic+release+from+the+degradation+of+polypropylene+feeding+bottles+during+infant+formula+preparation.">Microplastic release from the degradation of polypropylene feeding bottles during infant formula preparation.</a> Nature Food. , (2020).</li><li>Imhof, H. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pigments+and+plastic+in+limnetic+ecosystems:+A+qualitative+and+quantitative+study+on+microparticles+of+different+size+classes.">Pigments and plastic in limnetic ecosystems: A qualitative and quantitative study on microparticles of different size classes.</a> Water Research. 98, 64-74 (2016).</li><li>O&#223;mann, B. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Small-sized+microplastics+and+pigmented+particles+in+bottled+mineral+water.">Small-sized microplastics and pigmented particles in bottled mineral water.</a> Water Research. 141, 307-316 (2018).</li><li>World Health Organization. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+to+prepare+formula+for+bottle-feeding+at+home.">How to prepare formula for bottle-feeding at home.</a> World Health Organization. , (2007).</li><li>K&#228;ppler, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+environmental+microplastics+by+vibrational+microspectroscopy:+FTIR,+Raman+or+both.">Analysis of environmental microplastics by vibrational microspectroscopy: FTIR, Raman or both.</a> Analytical and Bioanalytical Chemistry. 408 (29), 8377-8391 (2016).</li><li>Zhao, S., Danley, M., Ward, J. E., Li, D., Mincer, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+approach+for+extraction,+characterization+and+quantitation+of+microplastic+in+natural+marine+snow+using+Raman+microscopy.">An approach for extraction, characterization and quantitation of microplastic in natural marine snow using Raman microscopy.</a> Analytical Methods. 9 (9), 1470-1478 (2017).</li><li>World Health Organization. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microplastics+in+drinking-water.">Microplastics in drinking-water.</a> World Health Organization. , (2019).</li><li>Sunta, U., Prosenc, F., Treb&#353;e, P., Bulc, T. G., Kralj, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adsorption+of+acetamiprid,+chlorantraniliprole+and+flubendiamide+on+different+type+of+microplastics+present+in+alluvial+soil.">Adsorption of acetamiprid, chlorantraniliprole and flubendiamide on different type of microplastics present in alluvial soil.</a> Chemosphere. 261, 127762 (2020).</li><li>Gong, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+analysis+on+the+sorption+kinetics+and+isotherms+of+fipronil+on+nondegradable+and+biodegradable+microplastics.">Comparative analysis on the sorption kinetics and isotherms of fipronil on nondegradable and biodegradable microplastics.</a> Environmental Pollution. 254, 112927 (2019).</li><li>Wong, M., Moyse, A., Lee, F., Sue, H. -. 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Though the study of MPs in marine and freshwater has been widely reported and the relevant standard protocol has been developed17, the study of daily-use plastic products is an important emerging research area. The different environmental conditions experienced by household plastic products means that extra care and efforts are needed to obtain reliable results. The study protocol must be consistent with the real daily use scenarios. For example, sonication is widely used in lab-tests to clean sam...

Most types of plastics are non-biodegradable but can break down into small pieces due to chemical and physical processes such as oxidation and mechanical friction1,2. Plastic pieces smaller than 5 mm are classified as microplastics (MPs). MPs are ubiquitous and found in almost every corner in the world. They have become a global concern due to the potential risk to humans and wildlife3,4. To date, significant accumulations of MPs have been found in fish, birds, insects5,6 as well as mammals (mouse, in the gut, kidney and liver7,8). Studies found that the exposure and accumulation of MPs can damage the lipid metabolism of mice7,8. A risk assessment focusing on fish found that sub-micron MPs can penetrate the blood-to-brain barrier and cause brain damage9. It should be noted that to date all MP risk results have been obtained from animal studies while the specific risk to human health is still unknown.
In the last 2 years, concerns about the MP threat to human health substantially increased with the confirmation of the levels of human exposure to MPs. The accumulation of MPs has been found in the human colon10, the placenta of pregnant women11 and adult stool12. A precise determination of MP release levels is crucial to identify exposure sources, assess the health risk and evaluate the efficiency of any potential control measures. In the last few years, some case studies reported that daily-use plastics (i.e., the plastic kettle13 and single-use cups14) can release extremely high quantities of MPs. For example, disposable paper cups (with interiors laminated with polyethylene-PE or copolymer films), released approximately 250 micron-sized MPs and 102 million sub-micron-sized particles into each milliliter of liquid following exposure to 85-90 &#176;C&#160;hot water14. A study of polypropylene (PP) food containers reported that up to 7.6 mg of plastic particles is released from the container during a single use15. Even higher levels were recorded from teabags made from polyethylene terephthalate (PET) and nylon, which released approximately 11.6 billion MPs and 3.1 billion nano-sized MPs into a single cup (10 mL) of the beverage16. Given that these daily-use plastic products are designed for food and beverage preparation, the release of high quantities of MPs is likely and their consumption is a potential threat to human health.
Studies on MP release from household plastic products (i.e., the plastic kettle13 and single-use cups14) are at an early stage, but it is expected that this topic will receive increasing attention from researchers and the general public. The methods required in these studies are significantly different from those used in room temperature marine or freshwater studies where well-established protocols already exist17. In contrast, studies involving the daily-use of household plastic products involves much higher temperature (up to 100 &#176;C), with in many cases repeated cycling back to room temperature. Previous studies pointed out that plastics in contact with hot water can release millions of MPs16,18. In addition, the daily-use of plastic products may over time change the properties of the plastic itself. It is therefore crucial to develop a sampling protocol that accurately mimics the most common daily-use scenarios. The detection of micro-sized particles is another major challenge. Previous studies pointed out that MPs release from plastic products are smaller than 20 &#181;m16,19,20. Detection of these types of MPs requires the use of smooth membrane filters with small pore size. In addition, it is necessary to distinguish MPs from possible contaminants captured by the filter. High sensitivity Raman spectroscopy is used for chemical composition analysis, which has the advantage of avoiding the need for high laser power that is known to easily destroy small particles20. Hence, the protocol must combine contamination-free handling procedures with the use of optimal membrane filters and for a characterization method that allows fast and accurate MP identification.
The study reported here focused on the PP-based baby feeding bottle (BFB), one of the most commonly used plastic products in daily life. It was found that a high number of MPs are released from plastic BFB during formula preparation18. For further study of MP release from daily plastics, the sample preparation and detection method for BFB is detailed here. During sample preparation, the standard formula-preparation process (cleaning, sterilizing and mixing) recommended by the WHO21 was carefully followed. By designing the protocols around the WHO guidelines, we ensured that the MP release from BFBs mimicked the baby formula preparation process used by parents. The filter process was designed to accurately collect the MPs released from BFBs. For the chemical identification of MPs, the working conditions for Raman spectroscopy were optimized to obtain clean and easily identified spectra of MPs, while at the same time avoiding the possibility of burning the target particles. Finally, the optimum test procedure and applied force to allow accurate 3-dimensional topography mapping of MPs using atomic force microscopy (AFM) was developed. The protocol (Figure 1) detailed here provides a reliable and cost-effective method for MP sample preparation and detection, which can substantially benefit future studies of plastic products.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>AFM cantilever</td>
			<td>NANOSENSORS</td>
			<td>PPP-NCSTAuD-10</td>
			<td>To obtain three-dimensional topography of PP MPs</td>
		</tr>
		<tr>
			<td>Atomic force microscope</td>
			<td>Nova</td>
			<td>NT-MDT</td>
			<td>To obtain three-dimensional topography of PP MPs</td>
		</tr>
		<tr>
			<td>Detergent</td>
			<td>Fairy Original</td>
			<td>1015054</td>
			<td>To clean the brand-new product</td>
		</tr>
		<tr>
			<td>Gold-coated polycarbonate-PC membrane filter-0.8 um</td>
			<td>APC, Germany</td>
			<td>0.8um25mmGold</td>
			<td>To collect microplastics in water and benefit for Raman test</td>
		</tr>
		<tr>
			<td>Gwyddion software</td>
			<td>Gwyddion</td>
			<td>Gwyddion2.54</td>
			<td>To determine MPs topography</td>
		</tr>
		<tr>
			<td>ImageJ software</td>
			<td>US National Institutes of Health</td>
			<td>No, free for use</td>
			<td>To determine MPs size</td>
		</tr>
		<tr>
			<td>Microwave oven</td>
			<td>De&#39;longhi, Italy</td>
			<td>815/1195</td>
			<td>Hot water preparation</td>
		</tr>
		<tr>
			<td>Optical microscope, x100</td>
			<td>Mitutoyo, Japan</td>
			<td>46-147</td>
			<td>To find and observe the small MPs</td>
		</tr>
		<tr>
			<td>Raman spectroscopy</td>
			<td>Renishaw</td>
			<td>InVia confocal Raman system</td>
			<td>To checmically determine the PP-MPs</td>
		</tr>
		<tr>
			<td>Shaking bed-SSL2</td>
			<td>Stuart, UK</td>
			<td>51900-64</td>
			<td>To mimic the mixing process during sample preparaton</td>
		</tr>
		<tr>
			<td>Standard polystyrene microplastic spheres</td>
			<td>Polysciences, Europe</td>
			<td>64050-15</td>
			<td>To validate the robusty of current protocol</td>
		</tr>
		<tr>
			<td>Tansfer pipette with glass tip</td>
			<td>Macro, Brand</td>
			<td>26200</td>
			<td>To transfer water sample to glass filter</td>
		</tr>
		<tr>
			<td>Ultrasonic cleaner</td>
			<td>Witeg, Germany</td>
			<td>DH.WUC.D06H</td>
			<td>To clean the glassware</td>
		</tr>
		<tr>
			<td>Vacuum pump</td>
			<td>ILMVAC GmbH</td>
			<td>105697</td>
			<td>To filter the water sample</td>
		</tr>
	</tbody>
</table>

sampling, identification and characterization of microplastics release from polypropylene baby feeding bottle during daily use

Microplastics (MPs) are becoming a global concern due to the potential risk to human health. Case studies of plastic products (i.e., plastic single-use cups and kettles) indicate that MP release during daily use can be extremely high. Precisely determining the MP release level is a crucial step to identify and quantify the exposure source and assess/control the corresponding risks stemming from this exposure. Though protocols for measuring MP levels in marine or freshwater has been well developed, the conditions experienced by household plastic products can vary widely. Many plastic products are exposed to frequent high temperatures (up to 100 &#176;C) and are cooled back to room temperature during daily use. It is therefore crucial to develop a sampling protocol that mimics the actual daily-use scenario for each particular product. This study focused on widely used polypropylene-based baby feeding bottles to develop a cost-effective protocol for MP release studies of many plastic products. The protocol developed here enables: 1) prevention of the potential contamination during sampling and detection; 2) realistic implementation of daily-use scenarios and accurate collection of the MPs released from baby feeding bottles based on WHO guidelines; and 3) cost-effective chemical determination and physical topography mapping of MPs released from baby feeding bottles. Based on this protocol, the recovery percentage using standard polystyrene MP (diameter of 2 &#181;m) was 92.4-101.2% while the detected size was around 102.2% of the designed size. The protocol detailed here provides a reliable and cost-effective method for MP sample preparation and detection, which can substantially benefit future studies of MP release from plastic products.

To validate this protocol, the water sample was prepared by adding standard polystyrene microplastic spheres (a diameter of 2.0 &#177; 0.1 &#181;m) to DI water. The MP quantity added corresponded to 4,500,000 particles/L, which is similar to the MP release level from BFBs. Following protocol sections 2-3, the MPs were successfully collected (Figure 4A) and the recovery rate was 92.4-101.2%. This recovery rate is comparable to a previous study on MPs23. Using ImageJ, t...

Watch this Scientific Journal Video about Sampling, Identification and Characterization of Microplastics Release from Polypropylene Baby Feeding Bottle during Daily Use at JoVE.com

Sampling, Identification and Characterization of Microplastics Release from Polypropylene Baby Feeding Bottle during Daily Use

This study detailed a reliable and cost-effective protocol for microplastics collection and detection from the daily use of plastic products.

Microplastics (MPs) are becoming a global concern due to the potential risk to human health. Case studies of plastic products (i.e., plastic single-use ...

Microplastics are becoming a global concern due to the potential risk to human health. This study focused on widely used polypropylene-based baby feeding bottles to develop a cost-effective protocol suitable for an MP study of many plastic products. This protocol provides the details of sample preparation, identification, and characterization.It can substantially benefit future studies of microplastics released from plastic products. Microplastics released during formula preparation. Soak the baby feeding bottle in 95 degrees Celsius deionized water to sterilize the bottle.To avoid the bottle floating, slightly press it using a stainless steel tweezer to ensure the whole bottle body is immersed in the water. After five minutes, take the bottle out and move it to a clean glass disk to await for air-drying. After air-drying, pour 180 milliliters of 70 degrees Celsius deionized water into the bottle.Then cover the bottle immediately using a glass Petri dish and place it onto a shaking bed. To stimulate the formula mixing process, shake the bottle at a speed of 180 rpm for 60 seconds. After shaking, move the bottle to a clean glass plate and allow it to cool down.Sample preparation for microplastics identification and quantification. Membrane filter is critical for microplastics capture, visualization, and detection. We used the gold coated polycarbonate membrane filter to capture microplastics.Place a piece of membrane filter in the middle of a glass base. Then assemble the glass funnel and stainless steel clamp to fix the membrane filter and connect the glass filter with a vacuum pump after gently shaking the cooled water sample in the baby-feeding bottle. Then transfer a certain amount of water sample to the glass funnel using a glass pipette.Switch on the vacuum pump to allow the water sample to filter through the membrane filter slowly. After filtering, wash the interior of the glass funnel using deionized water to ensure there are no particles sticking to the funnel. Disconnect the vacuum pump and disassemble the glass filter.Then, carefully take out the membrane filter using a stainless steel tweezer and move it to a clean cover glass. Store the sample in a clean glass Petri dish immediately. Microplastics identification and quantification.Carefully take out the sample from the glass Petri dish and place the filter sample in the middle of the Raman sample stage. Choose the representative spots in the membrane filter. Observe and photograph the particles on the surface of the membrane filter using an optical microscope.Set up the Raman system and test these particles one by one using 532 nanometer excitation laser at 10%intensity. Compare the Raman spectrum obtained to referenced standard spectra. The AFM and Raman spectroscopy are assembled in one system.Hence switch the system to AFM mode and test the topography of interesting microplastic particles. Microplastics test results. To validate this protocol, the standard polystyrene microplastics spheres were added to DI water and tested using the developed protocol.The PS microplastics were successfully collected and detected. The particle inside the red box was confirmed as a typical polystyrene microplastic. Following the protocol, the microplastics recovery rate was 92 to 101%Hence, the developed protocol is reliable for the baby-feeding bottle test.The protocol was used to test microplastics released from eight popular baby feeding bottle products, and found the microplastics released levels ranged from 1.3 million to 16.2 million particles per liter during formula preparation. The 3D topographic image further showed that the surface texture of the released microplastics is rich with nano sized bumps and valleys, which can substantially increase their absorption capacity.Conclusion. The study showed that plastic products that are used daily are very important sources for human microplastic exposure.The protocol detailed here provides a reliable and cost-effective method for microplastics sample preparation and detection, which can substantially benefit future studies of microplastic release from plastic products.

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Helminth Collection and Identification from Wildlife

Wild animals are commonly parasitized by a wide range of helminths. The four major types of helminths are &#34;roundworms&#34; (nematodes), &#34;thorny-headed worms&#34; (acanthocephalans), &#34;flukes&#34; (trematodes), and &#34;tapeworms&#34; (cestodes). The optimum method for collecting helminths is to examine a host that has been dead less than 4-6 hr since most helminths will still be alive. A thorough necropsy should be conducted and all major organs examined. Organs are washed over a 106 &#956;m sieve under running water and contents examined under a stereo microscope. All helminths are counted and a representative number are fixed (either in 70% ethanol, 10% buffered formalin, or alcohol-formalin-acetic acid). For species identification, helminths are either cleared in lactophenol (nematodes and small acanthocephalans) or stained (trematodes, cestodes, and large acanthocephalans) using Harris&#39; hematoxylin or Semichon&#39;s carmine. Helminths are keyed to species by examining different structures (e.g. male spicules in nematodes or the rostellum in cestodes). The protocols outlined here can be applied to any vertebrate animal. They require some expertise on recognizing the different organs and being able to differentiate helminths from other tissue debris or gut contents. Collection, preservation, and staining are straightforward techniques that require minimal equipment and reagents. Taxonomic identification, especially to species, can be very time consuming and might require the submission of specimens to an expert or DNA analysis.

Wild animals are commonly parasitized by a wide range of helminths.&#160; The four major types of helminths are &#8220;roundworms&#8221; (nematodes), &#8220;thorny-headed worms&#8221; (acanthocephalans), &#8220;flukes&#8221; (trematodes), and &#8220;tapeworms&#8221; (cestodes).&#160; Here we describe how helminths are collected from a vertebrate animal and how they are preserved and taxonomically identified.&#160;

Wild animals are commonly parasitized by a wide range of helminths. The four major types of helminths are &#34;roundworms&#34; (nematodes), ...

A Fish-feeding Laboratory Bioassay to Assess the Antipredatory Activity of Secondary Metabolites from the Tissues of Marine Organisms

Marine chemical ecology is a young discipline, having emerged from the collaboration of natural products chemists and marine ecologists in the 1980s with the goal of examining the ecological functions of secondary metabolites from the tissues of marine organisms. The result has been a progression of protocols that have increasingly refined the ecological relevance of the experimental approach. Here we present the most up-to-date version of a fish-feeding laboratory bioassay that enables investigators to assess the antipredatory activity of secondary metabolites from the tissues of marine organisms. Organic metabolites of all polarities are exhaustively extracted from the tissue of the target organism and reconstituted at natural concentrations in a nutritionally appropriate food matrix. Experimental food pellets are presented to a generalist predator in laboratory feeding assays to assess the antipredatory activity of the extract. The procedure described herein uses the bluehead, Thalassoma bifasciatum, to test the palatability of Caribbean marine invertebrates; however, the design may be readily adapted to other systems. Results obtained using this laboratory assay are an important prelude to field experiments that rely on the feeding responses of a full complement of potential predators. Additionally, this bioassay can be used to direct the isolation of feeding-deterrent metabolites through bioassay-guided fractionation. This feeding bioassay has advanced our understanding of the factors that control the distribution and abundance of marine invertebrates on Caribbean coral reefs and may inform investigations in diverse fields of inquiry, including pharmacology, biotechnology, and evolutionary ecology.

This bioassay employs a model predatory fish to assess the presence of feeding-deterrent metabolites from organic extracts of the tissues of marine organisms at natural concentrations using a nutritionally comparable food matrix.

Marine chemical ecology is a young discipline, having emerged from the collaboration of natural products chemists and marine ecologists in the 1980s with ...

Assaying Predatory Feeding Behaviors in Pristionchus and Other Nematodes

This protocol provides multiple methods for the analysis and quantification of predatory feeding behaviors in nematodes. Many nematode species including Pristionchus pacificus display complex behaviors, the most striking of which is the predation of other nematode larvae. However, as these behaviors are absent in the model organism Caenorhabditis elegans, they have thus far only recently been described in detail along with the development of reliable behavioral assays 1. These predatory behaviors are dependent upon phenotypically plastic but fixed mouth morphs making the correct identification and categorization of these animals essential. In P. pacificus there are two mouth types, the stenostomatous and eurystomatous morphs 2, with only the wide mouthed eurystomatous containing an extra tooth and being capable of killing other nematode larvae. Through the isolation of an abundance of size matched prey larvae and subsequent exposure to predatory nematodes, assays including both "corpse assays" and "bite assays" on correctly identified mouth morph nematodes are possible. These assays provide a means to rapidly quantify predation success rates and provide a detailed behavioral analysis of individual nematodes engaged in predatory feeding activities. In addition, with the use of a high-speed camera, visualization of changes in pharyngeal activity including tooth and pumping dynamics are also possible.

Assaying Predatory Feeding Behaviors in Pristionchus and Other Nematodes

Behavioral assays provide powerful tools for understanding neuronal function. Here we present several protocols for quantifying predatory feeding behavior found in the model nematode Pristionchus pacificus and its relatives. Additionally, we provide methods for analyzing predatory feeding adaptations including mouth structures and teeth.

This protocol provides multiple methods for the analysis and quantification of predatory feeding behaviors in nematodes. Many nematode species including ...

Protocol for Microplastics Sampling on the Sea Surface and Sample Analysis

Microplastic pollution in the marine environment is a scientific topic that has received increasing attention over the last decade. The majority of scientific publications address microplastic pollution of the sea surface. The protocol below describes the methodology for sampling, sample preparation, separation and chemical identification of microplastic particles. A manta net fixed on an &#187;A frame&#171; attached to the side of the vessel was used for sampling. Microplastic particles caught in the cod end of the net were separated from samples by visual identification and use of stereomicroscopes. Particles were analyzed for their size using an image analysis program and for their chemical structure using ATR-FTIR and micro FTIR spectroscopy. The described protocol is in line with recommendations for microplastics monitoring published by the Marine Strategy Framework Directive (MSFD) Technical Subgroup on Marine Litter. This written protocol with video guide will support the work of researchers that deal with microplastics monitoring all over the world.

The protocol below describes the methodology for: microplastics sampling on the sea surface, separation of microplastic and chemical identification of particles. This protocol is in line with the recommendations for microplastics monitoring published by the MSFD Technical Subgroup on Marine Litter.

Microplastic pollution in the marine environment is a scientific topic that has received increasing attention over the last decade. The majority of ...

Extraction and Characterization of Surfactants from Atmospheric Aerosols

Surface-active compounds, or surfactants, present in atmospheric aerosols are expected to play important roles in the formation of liquid water clouds in the Earth&#39;s atmosphere, a central process in meteorology, hydrology, and for the climate system. But because specific extraction and characterization of these compounds have been lacking for decades, very little is known on their identity, properties, mode of action and origins, thus preventing the full understanding of cloud formation and its potential links with the Earth&#39;s ecosystems.
In this paper we present recently developed methods for 1) the targeted extraction of all the surfactants from atmospheric aerosol samples and for the determination of 2) their absolute concentrations in the aerosol phase and 3) their static surface tension curves in water, including their Critical Micelle Concentration (CMC). These methods have been validated with 9 references surfactants, including anionic, cationic and non-ionic ones. Examples of results are presented for surfactants found in fine aerosol particles (diameter &#60;1 &#956;m) collected at a coastal site in Croatia and suggestions for future improvements and other characterizations than those presented are discussed.

Methods are presented for the targeted extraction of surfactants present in atmospheric aerosols and the determination of their absolute concentrations and surface tension curves in water, including their Critical Micelle Concentration (CMC).

Surface-active compounds, or surfactants, present in atmospheric aerosols are expected to play important roles in the formation of liquid water clouds in ...

Sampling, Sorting, and Characterizing Microplastics in Aquatic Environments with High Suspended Sediment Loads and Large Floating Debris

The ubiquitous presence of plastic debris in the ocean is widely recognized by the public, scientific communities, and government agencies. However, only recently have microplastics in freshwater systems, such as rivers and lakes, been quantified. Microplastic sampling at the surface usually consists of deploying drift nets behind either a stationary or moving boat, which limits the sampling to environments with low levels of suspended sediments and floating or submerged debris. Previous studies that employed drift nets to collect microplastic debris typically used nets with &#8805;300 &#181;m mesh size, allowing plastic debris (particles and fibers) below this size to pass through the net and elude quantification. The protocol detailed here enables: 1) sample collection in environments with high suspended loads and floating or submerged debris and 2) the capture and quantification of microplastic particles and fibers &lt;300 &#181;m. Water samples were collected using a peristaltic pump in low-density polyethylene (PE) containers to be stored before filtering and analysis in the lab. Filtration was done with a custom-made microplastic filtration device containing detachable union joints that housed nylon mesh sieves and mixed cellulose ester membrane filters. Mesh sieves and membrane filters were examined with a stereomicroscope to quantify and separate microplastic particulates and fibers. These materials were then examined using a micro-attenuated total reflectance Fourier transform infrared spectrometer (micro ATR-FTIR) to determine microplastic polymer type. Recovery was measured by spiking samples using blue PE particulates and green nylon fibers; percent recovery was determined to be 100% for particulates and 92% for fibers. This protocol will guide similar studies on microplastics in high velocity rivers with high concentrations of sediment. With simple modifications to the peristaltic pump and filtration device, users can collect and analyze various sample volumes and particulate sizes.

Most microplastic research to date has occurred in marine systems where suspended solid levels are relatively low. Focus is now shifting to freshwater systems, which may feature high sediment loads and floating debris. This protocol addresses collecting and analyzing microplastic samples from aquatic environments that contain high suspended solid loads.

The ubiquitous presence of plastic debris in the ocean is widely recognized by the public, scientific communities, and government agencies. However, only ...

Design and Use of an Apparatus for Quantifying Bivalve Suspension Feeding at Sea

As shellfish aquaculture moves from coastal embayments and estuaries to offshore locations, the need to quantify ecosystem interactions of farmed bivalves (i.e., mussels, oysters, and clams) presents new challenges. Quantitative data on the feeding behavior of suspension-feeding mollusks is necessary to determine important ecosystem interactions of offshore shellfish farms, including their carrying capacity, the competition with the zooplankton community, the availability of trophic resources at different depths, and the deposition to the benthos. The biodeposition method is used to quantify feeding variables in suspension-feeding bivalves in a natural setting and represents a more realistic proxy than laboratory experiments. This method, however, relies upon a stable platform to satisfy the requirements that water flow rates supplied to the shellfish remain constant and the bivalves are undisturbed. A flow-through device and process for using the biodeposition method to quantify the feeding of bivalve mollusks were modified from a land-based format for shipboard use by building a two-dimensional gimbal table around the device. Planimeter data reveal a minimal pitch and yaw of the chambers containing the test shellfish despite boat motion, the flow rates within the chambers remain constant, and operators are able to collect the biodeposits (feces and pseudofeces) with sufficient consistency to obtain accurate measurements of the bivalve clearance, filtration, selection, ingestion, rejection, and absorption at offshore shellfish aquaculture sites.

A flow-through device for using the biodeposition method to quantify filtration and feeding behavior of bivalve mollusks was modified for shipboard use. A two-dimensional gimbal table built around the device isolates the apparatus from boat motion, thereby allowing the accurate quantification of bivalve filtration variables at offshore shellfish aquaculture sites.

As shellfish aquaculture moves from coastal embayments and estuaries to offshore locations, the need to quantify ecosystem interactions of farmed bivalves ...

Generating Homo- and Heterografts Between Watermelon and Bottle Gourd for the Study of Cold-responsive MicroRNAs

MicroRNAs (miRNAs) are endogenous small non-coding RNAs of about 20 - 24 nt, known to play important roles in plant development and adaptation. There is an accumulating evidence showing that the expressions of certain miRNAs are altered when grafting, an agricultural practice commonly used by farmers to improve crop tolerance to biotic and abiotic stresses. Bottle gourd is an inherently climate-resilient crop compared to many other major cucurbits, including watermelon, rendering it one of the most widely used rootstocks for the latter. The recent advancement of high-throughput sequencing technologies has provided great opportunities to investigate cold-responsive miRNAs and their contributions to heterograft advantages; yet, adequate experimental procedures are a prerequisite for this purpose. Here, we present a detailed protocol for efficiently generating homo- and heterografts between the cold-susceptible watermelon and the cold-tolerant bottle gourd, in addition to methods of tissue sampling, data generation, and data analysis. The presented methods are also useful for other plant-grafting systems, to interrogate miRNA regulations under various environmental stresses, such as heat, drought, and salinity.

Here we present a detailed protocol for efficiently making homo- and heterografts between watermelon and bottle gourd, in addition to methods of tissue sampling, data generation, and data analysis, for the investigation of cold-responsive microRNAs.

MicroRNAs (miRNAs) are endogenous small non-coding RNAs of about 20 - 24 nt, known to play important roles in plant development and adaptation. There is ...

Long-term Video Tracking of Cohoused Aquatic Animals: A Case Study of the Daily Locomotor Activity of the Norway Lobster (Nephrops norvegicus)

We present a protocol related to a video-tracking technique based on the background subtraction and image thresholding that makes it possible to individually track cohoused animals. We tested the tracking routine with four cohoused Norway lobsters (Nephrops norvegicus) under light-darkness conditions for 5 days. The lobsters had been individually tagged. The experimental setup and the tracking techniques used are entirely based on the open source software. The comparison of the tracking output with a manual detection indicates that the lobsters were correctly detected 69% of the times. Among the correctly detected lobsters, their individual tags were correctly identified 89.5% of the times. Considering the frame rate used in the protocol and the movement rate of lobsters, the performance of the video tracking has a good quality, and the representative results support the validity of the protocol in producing valuable data for research needs (individual space occupancy or locomotor activity patterns). The protocol presented here can be easily customized and is, hence, transferable to other species where the individual tracking of specimens in a group can be valuable for answering research questions.

Long-term Video Tracking of Cohoused Aquatic Animals: A Case Study of the Daily Locomotor Activity of the Norway Lobster Nephrops norvegicus

Here we present a protocol to individually track animals over a long period of time. It uses computer vision methods to identify a set of manually constructed tags by using a group of lobsters as case study, simultaneously providing information on how to house, manipulate, and mark the lobsters.

We present a protocol related to a video-tracking technique based on the background subtraction and image thresholding that makes it possible to ...

Ecotoxicological Effects of Microplastics on Bird Embryo Development by Hatching without Eggshell

Microplastics are an emerging global pollutant type that poses a great health threat to animals due to their uptake and translocation in animal tissues and organs. Ecotoxicological effects of microplastics on the development of bird embryos are not known. The bird egg is a complete development and nutrition system, and the entire embryo development occurs in the eggshell. Therefore, a direct record of bird embryo development under the stress of pollutants such as microplastics is highly limited by the opaque eggshell in traditional hatching. In this study, the effects of microplastics on quail embryo development were visually monitored by hatching without an eggshell. The main steps include the cleaning and disinfection of fertilized eggs, the incubation before exposure, the short-term incubation after exposure, and the sample extraction. The results show that compared with the control group, the wet weight and body length of the microplastics-exposed group displayed a statistical difference and the liver proportion of the whole exposed group significantly increased. Additionally, we evaluated external factors that affect the incubation: temperature, humidity, egg rotation angle, and other conditions. This experimental method provides valuable information on the ecotoxicology of microplastics and a novel way to study the adverse effects of pollutants on the development of embryos.

This paper introduces a method of hatching without using an eggshell for toxicological studies of particle pollutants such as microplastics.

Microplastics are an emerging global pollutant type that poses a great health threat to animals due to their uptake and translocation in animal tissues ...