This research was supported by Grant 105AS-13.2.3-BQ-B1 from the Bureau of Animal and Plant Health Inspection and Quarantine, the Council of Agriculture, Executive Yuan and Grant 103-2313-B-197-002-MY3 from the Ministry of Science and Technology (MOST).

1. Preparations
<ol>
	<li>Make 1 L of 50% sugar syrup. Dissolve 1 kg sucrose in 1 L ddH2O.</li>
	<li>Prepare pyriproxyfen (PPN) solution in BLD. Make 1.1 L of 10,000 ppm PPN stock solution and dilute 100 mL PPN solution in 1 L sterilized ddH2O. Store at 4 &#176;C.</li>
	<li>Dilute the PPN stock solution to final concentrations of 0.1, 1, 10 and 100 mg/kg (ppm) in the BLD for the following experiment.</li>
	<li>Make PPN-syrup (for the colony level). Dilute the PPN stock to final concentrations of 10 and 100 ppm in 50% sugar syrup for the following experiment.</li>
	<li>Honey bee rearing. 
	Note: Here, the experimental location is the National Ilan University (NIU) apiary, Yi-Lan City, Taiwan; (GPS coordinates: N24.747278, E121.746200).
	<ol>
		<li>Check honey bee (Apis mellifera L.) colonies weekly for food quantity and feed with 1 liter 50% sugar syrup if necessary (the honey storage area is empty). Define a healthy colony as 9 frames of honey bee combs in each colony with a queen laying eggs normally.</li>
	</ol>
	</li>
	<li>Prepare 100 mL of basic larval diet (BLD). Dissolve 6% D-glucose, 6% fructose, and 1% yeast extract in sterilized distilled deionized water (ddH2O) and supplement with 50% royal jelly. Store at 4 &#176;C but not for more than 3 days. 
	Note: Pre-warm to 35 &#176;C before experiment and use within 3 days.</li>
</ol>
2. In Vivo Feeding Method
Note: In vivo feeding method has been modified from Hanley et al.20
<ol>
	<li>Honey bee larvae selection and labeling.
	<ol>
		<li>Insert a queen excluder to divide 9 frames of a healthy colony into 4 frames and 5 frames while limiting the queen to the 4 frame section. Leave at least one empty frame in the 4 frame section for laying eggs.</li>
		<li>After the queen laying eggs for 1 day, check the frames for the appearance of eggs and keep the eggs inside the beehives for 72 h (the 4th day) until 1 day-old larvae hatch. Take one of the frames containing 1-day-old worker larvae (hatched within 24 h) out from the test hive by hand and remove the honey bee workers from the frame with a bee brush.</li>
		<li>Cover the frame with a transparent slide (Size = Length x Width x thick = 29.7 mm x 21 mm x 0.1 mm) and nail the transparent slide on the edge of frames with thumbtacks (Figure 1A).</li>
		<li>For each treatment, randomly select 50 one day-old larvae (the 4th day) and mark each brood cell by using permanent marker pens on the transparent slide (Figures 1A and 1B). 
		Note: Write the information of each treatment on the frame and transparent slide as well by using permanent marker pens to avoid the confusion between different treatments. Remove the marked slides and keep for the in vivo feeding and observation.</li>
	</ol>
	</li>
	<li>In vivo feeding.
	<ol>
		<li>Add different concentrations of PPN-BLD (0.1, 1, 10 and 100 ppm) to each labeled brood cell by pipetting at day 1, 2 and 3 with 10 &#956;L, 10 &#956;L and 20 &#956;L, respectively, according to the intake quantity of the larvae age. Add the same amount of BLD (no PPN) to a control group. Thereby, the total dose of PPN-BLD in each labeled brood cell accumulates to 4, 40, 400, and 4,000 pg. 
		NOTE: Recognize the labeled brood cells by the marked transparent slides and remove the marked transparent slides after feeding. Use fresh BLD for feeding to prevent the cleaning of the brood cells by the worker bees.</li>
		<li>Return the PPN-treated frames to the original colonies for further observations. 
		NOTE: Each treatment has four biological repeats in four colonies.</li>
	</ol>
	</li>
	<li>Observation of treated larvae at day 7.
	<ol>
		<li>To observe the PPN-treated larvae, return the labeled transparent slides to the frames to record the mortality and capping rates in the labeled brood cells.</li>
	</ol>
	</li>
	<li>Observation of treated pupae and eclosion rates at day 13.
	<ol>
		<li>Remove the bee wax of capped brood cells.</li>
		<li>Put the soft tipped tweezers into brood cell and clamp the pupae very slightly then take pupae out gently.</li>
		<li>Transfer the pupae into 24-well tissue culture plates with a double-layer of laboratory tissues beneath each well. Record the damage and mortality during pupal transfer.</li>
		<li>Keep the 24-well tissue culture plates in an incubator at 34 &#176;C and 70% relative humidity until emergence (ca. 8 days).</li>
		<li>Observe and record the pupae and emerged honey bees.</li>
	</ol>
	</li>
	<li>Statistics
	<ol>
		<li>Calculate the recorded data and present as a mean &#177; S.D.</li>
		<li>Analyze the data using analysis of variance (ANOVA) by SAS and use the least significant difference (LSD) test to analyze the differences between two means of different treatments. Define statistically significant as P-value &#60;0.05. Different letters in the same column of the table showed a significant effect by the statistical analysis.</li>
	</ol>
	</li>
</ol>
3. Toxicity of PPN at Colony Level in Beehive
<ol>
	<li>Set up the honey bee groups.
	<ol>
		<li>Insert a queen excluder vertically to divide 9 frames of a healthy colony into 4 frames (Part A) and 5 frames (Part B) while limiting the queen to the 4 frame section . Leave at least one empty frame in the 4-frame section for laying eggs. 
		Note: Put another queen excluder the on top of the queen part to prevent the queen from moving between the parts.</li>
		<li>After the queen laying eggs for 1 day, check the frames for the appearance of eggs. Take the appropriate frames containing eggs out from part A by hand and remove the honey bee workers from the frame with a bee brush.</li>
		<li>Cover the frame with transparent slide and nail the transparent slide to the edge of the frame with thumbtacks.</li>
		<li>Randomly select 100 brood cells containing eggs and mark each brood cell by using permanent marker on the transparent slide. Assign these 100 brood cells as Group 1. Write the information of each treatment on the frame and transparent slide using permanent marker to avoid the confusion between different treatments.</li>
		<li>Return the labeled frame to part A for 3 days and then transfer the queen to part B to lay eggs.</li>
		<li>After 1 day, check the frames of part B, choose one appropriate frame and label 100 brood cells containing eggs as described in step 3.1.4. Assign these 100 brood cells as Group 2.</li>
		<li>Return the labeled frame to part B for 3 days and then transfer the queen to part A to lay eggs.</li>
		<li>Repeat the queen exchange between Part A and Part B 6 more times and assign groups numerically, respectively (Figure 2). There should be total of 9 groups.</li>
	</ol>
	</li>
	<li>Treat honey bee colony with PPN sugar syrup on day 13 (Figure 2).
	<ol>
		<li>Add 1 L 50% PPN sugar syrup containing 10 or 100 ppm in a plastic bee feeder box (W x L x H = 20 cm x 30 cm x 3.5 cm) and put the box on top of the frames in the experimental colonies. 
		Note: Group 1 does not receive the PPN at 13 days as the brood cells have been sealed.</li>
		<li>Feed the control group with 1 L 50% sugar syrup (no PPN) as described in step 2.2.</li>
	</ol>
	</li>
	<li>Count 1 day-old larvae and record as the egg hatching rate of 100 labeled brood cells for each group at day 5 (Figure 2). Honey bee eggs usually take 3 days to hatch into 0 day larvae; therefore, check and label 100 eggs-containing brood cells at day 1 and count the number of 1 day-old larvae for each group at day 5 to obtain the percentage of hatching rate.</li>
	<li>Count the capped brood cells and record as the larval capping rate of 100 labeled brood cells for each group at day 11 (Figure 2). 6 to 7 day-old larval brood cells will be capped with bee wax by honey bee workers for larvae pupating.</li>
	<li>Observe pupae maturation and record the eclosion rate of 100 labeled brood cells for each group at day 17 (Figure 2).
	<ol>
		<li>Remove the bee wax of capped brood cells and take pupae out with soft tipped tweezers gently. Transfer the pupae into a 24-well tissue culture plates with a double-layer of laboratory tissues beneath each well.</li>
		<li>Keep the 24-well tissue culture plates in an incubator at 34 &#176;C and 70% RH until emergence.</li>
		<li>Observe and record the pupae and emerged honey bees for each group until Group 9 (49 experimental days). 
		Note: Each treatment has four biological repeats.</li>
	</ol>
	</li>
	<li>Statistics
	<ol>
		<li>Calculate the recorded data and present as the mean &#177; SD.</li>
		<li>Analyze the significant differences between pairs of treatments (e.g. 0 ppm/10 ppm, 10 ppm/100 ppm and 0 ppm/100 ppm) in each group by using the Student&#39;s two-tailed t-test. Define as statistically significant if P-value &#60; 0.05.</li>
	</ol>
	</li>
</ol>

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The authors declare that they have no competing financial interests.

The queen-limited egg-laying method and queen-exchange method are critical steps for setting up honey bee groups for field testing within this protocol. The queen-limited egg-laying method permits synchronization of the life cycle of honey bees. Consequently, researchers can select 1 day-old larvae of the same age for treatment with different doses of pesticide. For the queen-exchange method, the queen was exchanged between part A (4 frames) and B (5 frames) to obtain different developmental stages of honey bee for field...

The presence of pesticides in the environment is one of the most serious problems that impacts the life of a honey bee1,2,3. Several studies have demonstrated the common presence of pesticide residues in honey bee colonies and bee products. In Taiwan, the average application of pesticides was 11-12 kg/ha every year (from 2005 to 2013). The amount of pesticides used in Taiwan is higher than that of the EU countries, and the Latin American countries4,5. In other words, the apicultural environment is suffering serious pesticide stress, especially in Taiwan and possibly in other countries.
The honey bee Apis mellifera is one of the major pollinators in agricultural systems6 and it also produces valuable products such as honey. However, honey bees are exposed to various pesticides and these pesticides can be brought back to beehives after foraging on flowers that have been sprayed with pesticides when collecting nectar and pollen7,8. They also can be exposed to pesticides by the beekeepers themselves aiming to control pest problems inside the hives9,10,11. Because honey bee larvae are fed by nurse bees for their development, larvae, drones and even the queen may be exposed to these pesticide-contaminated nectars and pollen12. The toxicity of various pesticides to honey bees needs to be addressed13.
Many efforts have been made to evaluate the issues of environmental pesticide residues. Yang et al. tested the influence of the neurotoxic insecticide imidacloprid on the development of honey bee larvae in the beehive and reported that a sub-lethal dose of imidacloprid resulted in olfactory associative behavior of the adult bees14. Also, Urlacher et al. examined the sub-lethal effects of an organophosphate pesticide, chlorpyrifos, on a honey bee worker&#39;s learning performance under laboratory conditions15. In our previous study, we evaluated the impact of an insect growth regulator (IGR), pyriproxyfen (PPN), on larval honey bees16.
In this paper, we present methods for evaluating the chemical impacts on the development of honey bees. Honey bee feeding methods were described and applied to either individual honey bees or to a colony. At first, we tested different concentrations of pesticide-contaminated basic larval diet (BLD) on larvae in the colonies to evaluate the impact of the pesticide on individual honey bees in vivo. We then proceeded to simulate the natural conditions of the pesticide by using pesticide-contaminated syrup within beehives. In this method, PPN, which is widely used against pest insects17 and is harmful to the development of honey bee larvae and pupae16,18,19, will be an indicator to represent the negative effect of the pesticide in the field.

<table border="0" cellpadding="0" cellspacing="0" width="887">
	<tbody>
		<tr height="22">
			<td height="22" style="height:22px;width:193px;">Honey bee box</td>
			<td style="width:243px;">SAN-YI Honey Factory</td>
			<td style="width:155px;">W1266</td>
			<td style="width:297px;">Honeybees rearing</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:193px;">Queen excluder (between frames)</td>
			<td style="width:243px;">SAN-YI Honey Factory</td>
			<td style="width:155px;">I1575</td>
			<td style="width:297px;">Queen limitation&#160;</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;width:193px;">Queen excluder (on top )</td>
			<td style="width:243px;">SAN-YI Honey Factory</td>
			<td style="width:155px;">I1566</td>
			<td style="width:297px;">Queen limitation on top&#160;</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;width:193px;">Bee brush</td>
			<td style="width:243px;">SAN-YI Honey Factory, Taiwan</td>
			<td>W1414</td>
			<td style="width:297px;">clean the bees on frame gently</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:18px;width:193px;">Bee feeder</td>
			<td style="width:243px;">SAN-YI Honey Factory, Taiwan</td>
			<td>P0219</td>
			<td style="width:297px;">feed sugar syrup to colony</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;">Transparent slide</td>
			<td style="width:243px;">Wan-Shih-Chei, Taiwan (http://www.mbsc.com.tw/a01goods.asp?s_id=40)</td>
			<td>1139</td>
			<td style="width:297px;">Mark the larval area on the frames (Material: Polyethylene Terephthalate, PET) (Size= Length*Width*thick= 29.7mm*21mm*0.1mm)</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:193px;">24 well tissu culture plate</td>
			<td style="width:243px;">Guangzhou Jet Bio-Filtration Co., Ltd</td>
			<td style="width:155px;">TCP011024</td>
			<td style="width:297px;">Rearing pupae from extraction</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:193px;">Autoclave</td>
			<td style="width:243px;">Tomin medical equipmenco., LTD.</td>
			<td style="width:155px;">TM-321</td>
			<td style="width:297px;">Make sterilized distilled deionized water (ddH2O)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">P20 pipetman</td>
			<td style="width:243px;">Gilson</td>
			<td style="width:155px;">F123600</td>
			<td style="width:297px;">Add PPN into bee larval food pool</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:193px;">Incubator&#160;</td>
			<td style="width:243px;">Yihder Co., Ltd.</td>
			<td style="width:155px;">LE-550RD</td>
			<td style="width:297px;">Rearing pupae from extraction</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;width:193px;">Kimwipes</td>
			<td style="width:243px;">COW LUNG INSTRUMENT CO., LTD</td>
			<td style="width:155px;">KCS34155</td>
			<td style="width:297px;">Rearing pupae from extraction</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:193px;">Royal jelly</td>
			<td style="width:243px;">National Ilan University (NIU)</td>
			<td style="width:155px;">NIU</td>
			<td style="width:297px;">Make basic larval diet (BLD)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">D-(+)-Glucose</td>
			<td style="width:243px;">Sigma</td>
			<td style="width:155px;">G8270</td>
			<td style="width:297px;">Make basic larval diet (BLD)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">D-(-)-Fructose</td>
			<td style="width:243px;">Sigma</td>
			<td style="width:155px;">F0127</td>
			<td style="width:297px;">Make basic larval diet (BLD)</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:193px;">Yeast extract</td>
			<td style="width:243px;">CONDA, pronadisa</td>
			<td style="width:155px;">1702</td>
			<td style="width:297px;">Make basic larval diet (BLD)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">Sucrose</td>
			<td style="width:243px;">Taiwan sugar coporation</td>
			<td style="width:155px;">E01071010</td>
			<td style="width:297px;">Make sugar syrup for bee food</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:193px;">Pyriproxyfen (11%)</td>
			<td style="width:243px;">LIH-NUNG CHEMICAL CO.. LTD.</td>
			<td style="width:155px;">Registration No. 1937</td>
			<td style="width:297px;">Insect growth regulator (IGR) used in the experiment</td>
		</tr>
	</tbody>
</table>

evaluating the effect of environmental chemicals on honey bee development from the individual to colony level

The presence of pesticides in the beekeeping environment is one of the most serious problems that impacts the life of a honey bee. Pesticides can be brought back to the beehive after the bees have foraged on flowers that have been sprayed with pesticides. Pesticide contaminated food can be exchanged between workers which then feed larvae and therefore can potentially affect the development of honey bees. Thus, residual pesticides in the environment can become a chronic damaging factor to honey bee populations and gradually lead to colony collapse. In the presented protocol, honey bee feeding methods are described and applied to either an individual honey bee or to a colony. Here, the insect growth regulator (IGR) pyriproxyfen (PPN), which is widely used to control pest insects and is harmful to the development of honey bee larvae and pupae, is used as the pesticide. The presenting procedure can be applied to other potentially harmful chemicals or honeybee pathogens for further studies.

For the honey bee field test, a queen was limited to the 4-frame section for laying eggs. This step could increase the brood density in one frame and facilitate subsequent observations. Each treatment was labelled, and the honey bees&#39; development was clearly observed through a transparent slide. In vivo feeding of PPN-BLD to honey bee larvae in the beehive was performed to precisely evaluate the influence of PPN on the development of honey bees in the colony. Using the in...

Watch this Scientific Journal Video about Evaluating the Effect of Environmental Chemicals on Honey Bee Development from the Individual to Colony Level at JoVE.com

Evaluating the Effect of Environmental Chemicals on Honey Bee Development from the Individual to Colony Level

Herein we present a method to feed pesticide contaminated food to both an individual honey bee and a beehive colony. The procedure evaluates the pesticide effect on individual honey bees by in vivo feeding of basic larval diet and also on the natural condition of beehive colony.

The presence of pesticides in the beekeeping environment is one of the most serious problems that impacts the life of a honey bee. Pesticides can be ...

evaluating-effect-environmental-chemicals-on-honey-bee-development

Research

JoVE Journal

Environment

9.0K Views.  National Ilan University. Herein we present a method to feed pesticide contaminated food to both an individual honey bee and a beehive colony. The procedure evaluates the pesticide effect on individual honey bees by in vivo feeding of basic larval diet and also on the natural condition of beehive colony.

Video: Evaluating the Effect of Environmental Chemicals on Honey Bee Development from the Individual to Colony Level

Automated Gel Size Selection to Improve the Quality of Next-generation Sequencing Libraries Prepared from Environmental Water Samples

Next-generation sequencing of environmental samples can be challenging because of the variable DNA quantity and quality in these samples. High quality DNA libraries are needed for optimal results from next-generation sequencing. Environmental samples such as water may have low quality and quantities of DNA as well as contaminants that co-precipitate with DNA. The mechanical and enzymatic processes involved in extraction and library preparation may further damage the DNA. Gel size selection enables purification and recovery of DNA fragments of a defined size for sequencing applications. Nevertheless, this task is one of the most time-consuming steps in the DNA library preparation workflow. The protocol described here enables complete automation of agarose gel loading, electrophoretic analysis, and recovery of targeted DNA fragments. 
In this study, we describe a high-throughput approach to prepare high quality DNA libraries from freshwater samples that can be applied also to other environmental samples. We used an indirect approach to concentrate bacterial cells from environmental freshwater samples; DNA was extracted using a commercially available DNA extraction kit, and DNA libraries were prepared using a commercial transposon-based protocol. DNA fragments of 500 to 800 bp were gel size selected using Ranger Technology, an automated electrophoresis workstation. Sequencing of the size-selected DNA libraries demonstrated significant improvements to read length and quality of the sequencing reads.

This manuscript describes an automated gel size selection approach for purifying DNA fragments for next-generation sequencing. The Ranger Technology provides complete automation of the entire process of agarose gel loading, electrophoretic analysis, and recovery of targeted DNA fragments allowing for high-throughput and high quality next-generation sequencing libraries.

Next-generation sequencing of environmental samples can be challenging because of the variable DNA quantity and quality in these samples. High quality DNA ...

Exploring the Effects of Atmospheric Forcings on Evaporation: Experimental Integration of the Atmospheric Boundary Layer and Shallow Subsurface

Evaporation is directly influenced by the interactions between the atmosphere, land surface and soil subsurface. This work aims to experimentally study evaporation under various surface boundary conditions to improve our current understanding and characterization of this multiphase phenomenon as well as to validate numerical heat and mass transfer theories that couple Navier-Stokes flow in the atmosphere and Darcian flow in the porous media. Experimental data were collected using a unique soil tank apparatus interfaced with a small climate controlled wind tunnel. The experimental apparatus was instrumented with a suite of state of the art sensor technologies for the continuous and autonomous collection of soil moisture, soil thermal properties, soil and air temperature, relative humidity, and wind speed. This experimental apparatus can be used to generate data under well controlled boundary conditions, allowing for better control and gathering of accurate data at scales of interest not feasible in the field. Induced airflow at several distinct wind speeds over the soil surface resulted in unique behavior of heat and mass transfer during the different evaporative stages.

A protocol for the design and construction of a soil tank interfaced to a small climate controlled wind tunnel to study the effects of atmospheric forcings on evaporation is presented. Both the soil tank and wind tunnel are instrumented with sensor technologies for the continuous in situ measurement of environmental conditions.

Evaporation is directly influenced by the interactions between the atmosphere, land surface and soil subsurface. This work aims to experimentally study ...

Removal of Trace Elements by Cupric Oxide Nanoparticles from Uranium In Situ Recovery Bleed Water and Its Effect on Cell Viability

In situ recovery (ISR) is the predominant method of uranium extraction in the United States. During ISR, uranium is leached from an ore body and extracted through ion exchange. The resultant production bleed water (PBW) contains contaminants such as arsenic and other heavy metals. Samples of PBW from an active ISR uranium facility were treated with cupric oxide nanoparticles (CuO-NPs). CuO-NP treatment of PBW reduced priority contaminants, including arsenic, selenium, uranium, and vanadium. Untreated and CuO-NP treated PBW was used as the liquid component of the cell growth media and changes in viability were determined by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay in human embryonic kidney (HEK 293) and human hepatocellular carcinoma (Hep G2) cells. CuO-NP treatment was associated with improved HEK and HEP cell viability. Limitations of this method include dilution of the PBW by growth media components and during osmolality adjustment as well as necessary pH adjustment. This method is limited in its wider context due to dilution effects and changes in the pH of the PBW which is traditionally slightly acidic&#160;however; this method could have a broader use assessing CuO-NP treatment in more neutral waters.

Removal of Trace Elements by Cupric Oxide Nanoparticles from Uranium In Situ Recovery Bleed Water and Its Effect on Cell Viability

Production bleed water (PBW) was treated with cupric oxide nanoparticles (CuO-NPs) and cellular toxicity was assessed in cultured human cells. The goal of this protocol was to integrate the native environmental sample into a cell culture format assessing the changes in toxicity due to CuO-NP treatment.

In situ recovery (ISR) is the predominant method of uranium extraction in the United States. During ISR, uranium is leached from an ore body and extracted ...

A Flow-through Exposure System for Evaluating Suspended Sediments Effects on Aquatic Life

This paper describes the Fish Larvae and Egg Exposure System (FLEES). The flow-through exposure system is used to investigate the effects of suspended sediment on various aquatic species and life stages in the laboratory by using pumps and automating delivery of sediment and water to simulate suspension of sediment. FLEES data are used to develop exposure-response curves between the effects on aquatic organisms and suspended sediment concentrations at the desired exposure duration. The effects data are used to evaluate management practices used to reduce the interactions between aquatic organisms and anthropogenic causes of suspended sediments. The FLEES is capable of generating total suspended solids (TSS) concentrations as low as 30 to as high as 800 mg/L, making this system an ideal choice for evaluating the effects of TSS resulting from many activities including simulating low ambient levels of TSS to evaluating sources of suspended sediments from dredging operations, vessel traffic, freshets, and storms.

A robust and flexible flow-through exposure system designed to maintain sediment in suspension is presented. The system is used to investigate the effects of suspended sediment on various aquatic species and life stages in the laboratory.

This paper describes the Fish Larvae and Egg Exposure System (FLEES). The flow-through exposure system is used to investigate the effects of suspended ...

Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis

Plastic resin pellets, categorized as microplastics (&#8804;5 mm in diameter), are small granules that can be unintentionally released to the environment during manufacturing and transport. Because of their environmental persistence, they are widely distributed in the oceans and on beaches all over the world. They can act as a vector of potentially toxic organic compounds (e.g., polychlorinated biphenyls) and might consequently negatively affect marine organisms. Their possible impacts along the food chain are not yet well understood. In order to assess the hazards associated with the occurrence of plastic pellets in the marine environment, it is necessary to develop methodologies that allow for rapid determination of associated organic contaminant levels. The present protocol describes the different steps required for sampling resin pellets, analyzing adsorbed organochlorine pesticides (OCPs) and identifying the plastic type. The focus is on the extraction of OCPs from plastic pellets by means of a pressurized fluid extractor (PFE) and on the polymer chemical analysis applying Fourier Transform-InfraRed (FT-IR) spectroscopy. The developed methodology focuses on 11 OCPs and related compounds, including dichlorodiphenyltrichloroethane (DDT) and its two main metabolites, lindane and two production isomers, as well as the two biologically active isomers of technical endosulfan. This protocol constitutes a simple and rapid alternative to existing methodology for evaluating the concentration of organic contaminants adsorbed on plastic pieces.

Microplastics act as vector of potentially toxic organic contaminants with unpredictable effects. This protocol describes an alternative methodology for assessing the levels of organochlorine pesticides adsorbed on plastic pellets and identifying the polymer chemical structure. The focus is on pressurized fluid extraction and attenuated total reflectance Fourier transform infrared spectroscopy.

Plastic resin pellets, categorized as microplastics (&#8804;5 mm in diameter), are small granules that can be unintentionally released to the environment ...

Preparation of DMMTAV and DMDTAV Using DMAV for Environmental Applications: Synthesis, Purification, and Confirmation

Dimethylated thioarsenicals such as dimethylmonothioarsinic acid (DMMTAV) and dimethyldithioarsinic acid (DMDTAV), which are produced by the metabolic pathway of dimethylarsinic acid (DMAV) thiolation, have been recently found in the environment as well as human organs. DMMTAV and DMDTAV can be quantified to determine the ecological effects of dimethylated thioarsenicals and their stability in environmental media. The synthesis method for these compounds is unstandardized, making replicating previous studies challenging. Furthermore, there is a lack of information about storage techniques, including storage of compounds without species transformation. Moreover, because only limited information about synthesis methods is available, there may be experimental difficulties in synthesizing standard chemicals and performing quantitative analysis. The protocol presented herein provides a practically modified synthesis method for the dimethylated thioarsenicals, DMMTAV and DMDTAV, and will help in the quantification of species separation analysis using high performance liquid chromatography in conjunction with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The experimental steps of this procedure were modified by focusing on the preparation of chemical reagents, filtration methods, and storage.

Preparation of DMMTAV and DMDTAV Using DMAV for Environmental Applications: Synthesis, Purification, and Confirmation

This article presents modified experimental protocols for dimethylmonothioarsinic acid (DMMTAV) and dimethyldithioarsinic acid (DMDTAV) synthesis, inducing dimethylarsinic acid (DMAV) thiolation through mixing of DMAV, Na2S, and H2SO4. The modified protocol provides an experimental guideline, thereby overcoming limitations of the synthesis steps that could have caused experimental failures in quantitative analysis.

Dimethylated thioarsenicals such as dimethylmonothioarsinic acid (DMMTAV) and dimethyldithioarsinic acid (DMDTAV), which are produced by the metabolic ...

The Effect of the Application of Thyme Essential Oil on Microbial Load During Meat Drying

Meat is a high protein meal that is used in the preparation of jerky, a popular food snack, where preservation and safety are important. To assure food safety and to extend the shelf life of meat and meat products, the use of either synthetic or natural preservatives have been applied to control and eliminate foodborne bacteria. A growing interest in the application of natural food additives for meat has increased. Microorganisms, such as Escherichia coli, contaminate meat and meat products, causing foodborne illnesses. Therefore, it is necessary to improve the meat conservation process. However, the use of essential oils when the meat is being dried has not been deeply studied. In this regard, there is an opportunity to increase the value of dried meat and reduce the risk of foodborne illnesses by applying essential oils during the drying process. In this protocol, we present a novel method of applying thyme essential oil (TEO) during meat drying, specifically in vapor form directly in a drying chamber. For evaluation, we use Minimal Inhibitory Concentration (MIC) to detect the number of harmful bacteria in the treated samples compared to raw samples. The preliminary results show that this method is a viable and alternative option to synthetic preservatives and that it significantly reduces microbial load in dried meat.

Microorganisms such as Escherichia coli that contaminate meat products cause foodborne illnesses. The use of essential oils in the meat drying process has not been deeply studied. Here, we present a novel method of applying thyme essential oil to meat during drying to reduce the microbial load in dried meat.

Meat is a high protein meal that is used in the preparation of jerky, a popular food snack, where preservation and safety are important. To assure food ...

Protocol for Acute and Chronic Ecotoxicity Testing of the Turquoise Killifish Nothobranchius furzeri

The killifish Nothobranchius furzeri is an emerging model organism in the field of ecotoxicology and its applicability in acute and chronic ecotoxicity testing has been demonstrated. Overall, the sensitivity of the species to toxic compounds is in the range with, or higher than, that of other model species.
This work describes protocols for acute, chronic, and multigenerational bioassays of single and combined stressor effects on N. furzeri. Due to its short maturation time and life-cycle, this vertebrate model allows the study of endpoints such as maturation time and fecundity within four months. Transgenerational full life-cycle exposure trials can be performed in as little as 8 months. Since this species produces eggs that are drought-resistant and remain viable for years, the on-site culture of the species is not needed but individuals can be recruited when required. The protocols are designed to measure life-history traits (mortality, growth, fecundity, weight) and critical thermal maximum.

Protocol for Acute and Chronic Ecotoxicity Testing of the Turquoise Killifish Nothobranchius furzeri

In this work, we describe an acute, chronic and multigenerational bioassay to study the effects of single and combined stressors on the Turquoise killifish Nothobranchius furzeri. This protocol is designed to study life-history traits (mortality, growth, fecundity, weight) and critical thermal maximum.

The killifish Nothobranchius furzeri is an emerging model organism in the field of ecotoxicology and its applicability in acute and chronic ecotoxicity ...

Measuring Hypopharyngeal Gland Acinus Size in Honey Bee (Apis mellifera) Workers

The nurse hypopharyngeal glands produce the protein fraction of the worker and royal jelly that is fed to developing larvae and queens. These paired glands that are located in the head of the bee are highly sensitive to the quantity and quality of pollen and pollen substitutes that the nurse bee consumes. The glands get smaller when nurses are fed deficient diets and are large when they are fed complete diets. Because nurse hypopharyngeal gland size is a robust indicator of nurse nutrition, it is essential that those studying honey bee nutrition know how to measure these glands. Here, we provide detailed methods for dissecting, staining, imaging, and measuring nurse bee hypopharyngeal glands. We present comparisons of unstained and stained tissue and data that were used to study the impact of pollen on gland size. This method has been used to test how diet impacts hypopharyngeal gland size but has further use for understanding the role of these glands in hive health.

Measuring Hypopharyngeal Gland Acinus Size in Honey Bee Apis mellifera Workers

Hypopharyngeal gland acinus size is a robust measure of nurse honey bee nutrition. Here, we provide a detailed protocol for dissecting, staining, imaging, and measuring nurse bee hypopharyngeal gland acini.

The nurse hypopharyngeal glands produce the protein fraction of the worker and royal jelly that is fed to developing larvae and queens. These paired ...

Composition and Distribution Analysis of Bioaerosols Under Different Environmental Conditions

Variable microorganisms in particulate matter (PM) under different environmental conditions may have significant impacts on human health. In this study, we described a protocol for multiple analyses of the biological compositions in environmental PM. Five experiments are presented: (1) PM number monitoring by using a laser particle counter; (2) PM collection by using a cyclonic aerosol sampler; (3) PM collection by using a high-volume air sampler with filters; (4) culturable microbes collection by the Andersen six-stage sampler; and (5) detection of biological composition of environmental PM by bacterial 16SrDNA and fungal ITS region sequencing. We selected hazy days and a livestock farm as two typical examples of the application in this protocol. In this study, these two sampling methods, cyclonic aerosol sampler and filter sampler, showed different sampling efficiency. The cyclonic aerosol sampler performed much better in terms of collecting bacteria, while these two methods showed the same efficiency in collecting fungi. Filter samplers can work under low temperature conditions while cyclonic aerosol samplers have a sampling limitation for temperature. A solid impacting sampler, such as an Andersen six-stage sampler, can be used to sample bioaerosols directly into the culture medium, which increases the survival rate of culturable microorganisms. However, this method mainly relies on culture while more than 99% of microbes cannot be cultured. DNA extracted from the culturable bacteria collected by the Andersen six-stage sampler and samples collected by cyclonic aerosol sampler and filter sampler were detected by bacterial 16S rDNA and fungal ITS region sequencing.All the methods above may have wide application in many fields of study, such as environmental monitoring and airborne pathogen detection. From these results, we can conclude that these methods can be used under different conditions and may help other researchers further explore the health impacts of environmental bioaerosols.

Understanding the biological composition of environmental particulate matter is important for the study of its significant impacts on human health and disease spread. Here, we used three types of bioaerosol sampling methods and a biological analysis of airborne microbes to better explore airborne microbial communities under different environmental conditions.

Variable microorganisms in particulate matter (PM) under different environmental conditions may have significant impacts on human health. In this study, ...