Hey, it’s the other intern, Marta. I’m the one that has been performing experiments on the circadian rhythm of the cockroaches. It’s like Sleeping Beauty, but with cockroaches! The last time I wrote a blog, I was using the Blaberus Discoidalis, but because the Periplaneta Americana deemed to be the better choice, since “they’re more active”, that’s the breed that I got stuck with. Don’t get me wrong, they’re great for my experiment, but they require a high amount of concentration and dedication to put them in a box without them running away…
Anyway, back to my experiment… I have made much progress in the past 4 weeks ago (I would be worried if I didn’t). About four weeks ago, my “mini” experiments were based on testing the emitter/detector and PIR sensors. And I generally focused on coding and setting up the apparatus as a whole. Now I am at the point where I have everything coded (with the help of Jake Robbins, our lab tech), and have the general setup of the circadian rhythm terrarium.
One of the main issues that I have ran into thus far, is finding a decent sensor to detect the cockroach. My first sensor, the PIR sensor, was very unreliable when it came to detecting the cockroach because it wasn’t sensitive enough. After doing many tests with that sensor, I decided to cut it from my experiment completely. The second sensor, the emitter and detector, labeled as my “inside sensors”, proved to be better than the PIR sensor. Its main purpose is to detect any “breaks” in the signal. The only issue with it is that it produced too much noise in the raw data. For now, they are attached to the top of the wheel in my first experiment box, but will not be in my other two boxes. My third sensor, the reflective sensor, is my “outside sensor” because it is attached to the outside of the exercise wheel, and detects the changes in the white-black stripes when the exercise wheel rotates (when the cockroach runs on the wheel).
After doing many small experiments, it has proved to be the most efficient and will be the main sensor used in the experiment. To code and test my data, I have been using an Arduino Uno, an Adafruit shield, and an LCD screen.
But after realizing I don’t really need the LCD screen, I eliminated that out of my experiment as well. Another issue that I have ran into is not being able to detect enough motion produced by the cockroach. One of the ideas (that we eventually went with) included enclosing the cockroach inside the wheel, and adding an acrylic door that you can open and shut, but that didn’t seem like the best option because of the many unaesthetic features. So, we changed the wheel, we changed the sensors, but the one thing that hasn’t been touched is the actual box that the wheel is in.
Then one night at 1:30 a.m., I randomly had an idea to change the size of the box. If we do not need that extra space for the cockroach in, then what’s the point of having the box so big? Because time is running out, there was no time to actually build a whole new box, so instead I placed a divider in order to eliminate the amount of area that the cockroach can run in, and somewhat “enclose” the cockroach so it would be able to run on the wheel. I also vaselined the walls because one of the main issues with the Americana is that they can climb. So, by vaselining the walls, I can eliminate the chance of the cockroaches climbing up the walls.
Other issues that I have had consist of a cockroach running away from me (still don’t know how since everything was sealed shut), cockroaches dying on me, and my arduino uno being a piece of junk and failing on me.
One of the most stressful parts of this project has been dealing with the small things. The big issues have been the easiest to solve thus far. This whole process has made me appreciate the research field much more and this project definitely has been a lot harder than I initially thought it would be. Some other exciting things to note: we have a temperature sensor working to show that we have a consistent environment, and a light sensor, to tell when the lights go off and on!
We use a time stamp feature so we can see the exact time of day instead of using the millis feature, which only shows the milliseconds. I have a strip of LED lights that are wired to a 12-12 light-dark cycle at the moment, and my experiment is placed in a room what Alex (the other intern) calls the “Dungeon” because it is pitch black and also very eerie.
Within the room, I have my experiment placed inside a tub, with the lights streaming inside this tub as well.
Then on top of the tub, I have the arduino sitting on it. It is not the prettiest setup, but it collects data, and it works.
I run the experiments all throughout the day, and actually, last night was one of the first nights where something dramatically bad didn’t happen to my data (so that’s exciting). The data thus far shows that the cockroach has been running on the wheel, but we are adding one more similar experiment box for further data, and along with that, we are also adding another wheel that, like I mentioned earlier, encloses the cockroach within the wheel.
With that, the cockroach will randomly be fed, but at least with that method, we will be sure that the cockroach is running on the wheel, and we have more data. I hope to set up the other experiment boxes very soon to get that other data coming in, and then I hope to soon switch from the 12-12 cycle to 24 hours of complete darkness. I also have been working on Python so I’ll have a way to analyze my data. Anyway, I can’t wait to see the final results of my experiment!
Night time in Ann Arbor for us interns, but now it’s daytime for my subject!