Research Experience

Yesterday and today we prepared to begin the chronic tests. These are the tests that will determine whether or not carbon nanotubes have an impact on water flea reproduction. Yesterday I transferred the 40 moms into new cups. Four had died. I then counted the neonates in each cup. Many of the cups had no offspring. Other only had a few. When I transferred the moms and counted the neonates today I found between 10 and 17 neonates in each cup! Those neonates were transferred to individual cups with varying concentrations of carbon nanotubes. There were 5 different concentrations and a control. For each concentration and the control there were 10 cups (making a total of 60 cups). We will continue the count the neonates as we had the past two weeks but now we will be looking to see if there seems to be any correlation between the concentration of carbon nanotubes and the amount of neonates produced.

Today I looked at the 40 water fleas that I had selected on Tuesday.  They have grown in size over the past two days and are now visible without using a magnifying glass.  I transferred each of the 40 into new cups with fresh water and food (algae).  I also checked to see if any of them produced broods.  They had not.  I would suspect that they will by tomorrow or Saturday.  The graduate student I am working with will be doing the counts over the weekend.  Apparently water flea reproduction does not take the weekend off, even though I do.  The water flea in cup #12 was MIA.  I am not sure if this was an error on my part and I accidently did not transfer it into the cup or if something else happened.  When I did the initial transfers two days ago the water fleas were so small that they could not be seen without the aid of the magnifying glass and it is possible that I missed the neonate with the pipet.

Now that the water fleas have had the opportunity to produce several broods of neonates we are beginning the selection process of neonates that will be used in the toxicity study.  We took the neonates from the 4th brood and randomly selected 40.  Those that we selected from came from moms who had shown high   The neonates that were selected were then transferred to individual cups and will be allowed to develop and then reproduction rates.

I am thinking of several ways to apply in the classroom.  Basically I can incorporate the techniques used in this study into many other kinds of toxicity studies.  I was thinking of creating a lab in which the students will look at the effects of pH on the mortality of Daphnia.

I have basically been working on setting up the experiment.  We are looking to see what the effects are of carbon nanotubes on Ceriodaphnia dubia, also commonly known as the water flea.  This is a toxicity study and will we be looking at effects of the carbon nanotubes on reproduction.  To the best of my understanding, the reason why we are looking at effects of carbon nanotubes is because it a new material that is become more widely used (similar to graphite).  The reason why we are looking at the water flea is because they are recommended by the EPA as an biological environmental indicator.

What I did last Friday and today was observe the mothers and make sure that they were healthy and count the number of neonates (young) in each of their broods.  We are in the process of selecting neonates from mothers who produced large broods in hopes that they will have large broods as well.  Those selected will be used in the toxicity study.

I would like to design a laboratory activity based on the research that I am conducting this summer for use with my honors 9th grade students as part of the unit on Wetlands and Watersheds.
I would also like to find new ways to incorporate mathematics into the science curriculum.