Spot the Drosophila

While I was out shopping today, I was reminded of something that I do when I go to the fruit section of a supermarket or store. Whenever I'm in the fruit section, I always look out for Drosophila. For those of you who might not know, Drosophila melanogaster is a model organism for genetics experiments. They use these insects for genetics experiments for reasons including that they have short generation times, make lots of offspring, don't cost much to maintain and allegedly have not much capacity for thought (so little or no ethics approval is needed for experiments). Due to evolution and organisms on earth descending from a common ancestor, many genes in humans and other animals are also found in Drosophila, but not all.

There's many species of Drosophila and the random fruit flies in the store are unlikely to be the same species as the one used in experiments. However, sometimes I find one which has that bright red eye which looks like it can be, but I'm not an expert so I don't know for sure. Anyway, here's a photo of a Drosophila that I took last year from a fruit and vegetable store. This one's probably not D. melanogaster though.

Oh and these binomial names reminds me of my first prac submission for first year biology. I didn't underline any of my species names (in typing you're supposed to italicize and in writing you should underline). So I got deducted a few marks. Now if I go to a walking track and the person who made the signs forgot to italicize (like when I went to Queensland at the start of this year), I really notice it.

[update] First anatomy prac session for medicine

Today I had my first anatomy prac for medicine. It's been about one and a half years since my last anatomy prac in biomed, since I didn't major in anatomy. I was looking forward to it again; feeling the tough arteries spring back and poking at lungs.

When I heard that it was going to be "self directed" (or words to that meaning), I thought: "not again". But it was OK if you listened to demonstrators whenever they said something. Sometimes the demonstrators would teach beyond what questions were asked, and you could even feel as if it was a normal tutorial without thinking it was self directed.

The interesting part about today was seeing an anatomical variation on a specimen. I noticed that the arch of aorta of one of the specimens ran to the right of the trachea instead of to the left. It was good to see for myself, because in anatomy we usually just learn the case in the "majority" of people.

We don't seem to have many anatomy pracs in Melbourne, or lectures for that matter. Then again, we were all required to do a subject of anatomy before entering medicine at Melbourne as a prerequisite, so we all had to do about 44 hours of anatomy before entering to start with (according to the anatomy second year subject for Bachelor of Science handbook link from Melbourne).

Anyway, it seems like I'll be having a dissection prac in 3 weeks; after the midsemester break. I'm looking forward to it. I didn't do any dissections before in anatomy, since I didn't do my major in it and at Melbourne you don't get to dissect in the second year anatomy subject.

Number tricks: multiplying and dividing by 10

The GAMSAT this year happened yesterday. If you did the GAMSAT yesterday, I hope that you went well.

While I was helping someone with some GAMSAT questions for practice this year, without a calculator, I was reminded of some number tricks which can sometimes help. When calculators are available they aren't really required, but without calculators, the tricks can be helpful. You won't always be able to use tricks in calculations, but when you can, they can save time.

The trick I'll be discussing is multiplying and dividing by multiples of 10. Essentially, this simply involves moving the decimal point. It is sometimes useful if you are dealing with decimal multiplications or divisions.

Example 1:

300*0.04

Just divide the 300 by 100 (ie move the decimal point 2 to the left for 300) and multiply the 0.04 by 100 (ie move the decimal point 2 to the right for 0.04). Then the product becomes easier.

=3*4=12

Example 2:

0.0075/0.00015

Multiply the numerator and denominator by 100000 (ie move the decimal point for both 5 spaces to the right).

=750/15=50


Tricks like these can sometimes cut out time for decimal calculations.

[update] Blood Pressure measurements with the Finometer device

As I said on my last post, the University of Melbourne was doing a study about blood pressure and how polymorphisms in a gene for a sodium channel affects it. We had another prac today, for the follow-up since some of us were allocated to take sodium tablets for two weeks (and everyone else did more measurements even without taking the tablets too).

I got the results from three weeks ago of the readings of a "Finometer" before and after taking GTN (glyceryl trinitrate, aka nitroglycerin; used for treatment in angina, which dilates blood vessels), and before, during and after standing up from lying down. The Finometer measured a lot of different things (and calculated others using algorithms) in real time; including blood pressure (systolic and diastolic), heart rate, stroke volume, cardiac output and total peripheral resistance.

I was somewhat surprised at how much the blood pressure dropped when I stood up. Without the GTN, straight after standing up, the lowest systolic measured for me was 54 mmHg and for diastolic it was 34 mmHg, even though I am relatively young so the reflexes should not be too bad. After taking GTN, straight after standing up, the lowest systolic measured was 37 mmHg and lowest diastolic was as low as 18 mmHg! I never expected that my blood pressure would ever be that low, but now I know.

The professor/demonstrator then told me that now I should be able to understand why a lot of old people faint when they take GTN and try to stand up. For some reason, I might have felt a little dizzy, but even when my blood pressure was as low as 37/18 I still didn't feel like I was about to faint. Strange. Maybe because it was only for a few seconds.

[update] Urine collection day.

If anyone wants to know, today is the day that I am doing a 24 hour urine collection. At UniMelb, there are people who are running a study determining the effects of the polymorphisms of a sodium channel gene on blood pressure. All the first year medical students were invited to take part in the study to aid in the research of the professors at the university.

Of course, what the uni gets out of it is about 300 more students to get data points out of, without needing to pay financial reimbursement. They need large data sets for determining the effects of certain genes, especially if they do not have a large impact on blood pressure.

For the students, they made it an opportunity for us to learn how to measure blood pressure by auscultation. I think I can do it reasonably comfortably now. It's a lot easier in a quiet room than a prac room where everyone is talking though.

It was also marketed as an opportunity for us to get involved with research, since the University of Melbourne is a highly research intensive university, and because the MD had a focus on research; having a semester dedicated to it.

Finally, they told us that it was good to experience doing a 24 hour urine collection so we know how patients feel when we tell them to do it later on, and so we can explain it better. Meanwhile, my collection bottle seems to be filling at too high of a rate, so maybe I should reduce my water intake for the rest of the day. I don't want to have to carry two urine containers to uni!

Selective Entry Accelerated Learning Programs

When I was in grade six, along with about 100 people, I sat a test to get into the accelerated learning program at a high school. I got in, and a quarter of the test takers would later form an accelerated class at our school.

At my high school, the structure was such that we did year 8 maths (and some covered year 7 and a bit of year 8 of other core subjects like English and science) in year 7, year 9 maths in year 8 (covering the rest of year 8 science and year 9 science, and up to year 9 English), skipping year 9 and doing almost the same things as all the other year 10 classes in year 10 if we decided to stay on at the school and not go to Melbourne High School (MHS) or Mac.Robertson Girls' High School (MacRob) for example.

From then, we had the opportunity to do "two year VCE" if we wanted to, to finish high school a year earlier, or "three year VCE" if we wanted to use up a year "saved" to try to get a better mark in VCE. I took up the "two year VCE" option, like a lot of my peers, and subsequently successfully completed VCE, completed Biomedicine in the usual time, and I'm now in medicine.

However, after my year level went straight to year 10 and skipped year 9, the school decided to change the arrangements of the accelerated program for future year levels. Instead of skipping year 9, you did mainly year 10 core subjects in year 9. In "year 10", students were required to take up year 11 English, History and Mathematical Methods (mid-level VCE maths). Due to the inflexibility of the subjects possible for electives, it effectively forced people to undergo "three year VCE", with the first year being year 10.

To be honest, I was quite baffled with their change in policy at the school. I personally did not feel that there was much wrong with the old "two year VCE" after acceleration system. What was so wrong about people leaving school one year early, when they were entirely capable of doing so and able to study at university? Surely going to university would be more effective use of their time than staying back at school for another year.

The stated reason from the school seemed to be due to concerns about the maturity about the students leaving. There was concern that the people undergoing two year VCE after being in the accelerated learning program would not be mature enough to go to university because they were one year younger. While this is a point which may be true for some people, I don't think it is a good reason to keep everyone back. Myself and many others who have done "two year VCE" after being part of the accelerated program have managed to successfully complete a bachelor degree within the normal time frame. (In hindsight, maybe I could have skipped two years too, seeing that my GAMSAT score in 2010 was still clearly enough for UQ medicine for a CSP place for 2011 entry, or 2012 entry for that matter, without an interview.) Furthermore, for those who may not be ready for university that early, they still did have the option of "three year VCE" to use up their "saved" year.

Furthermore, being unable to skip a year anymore at my high school (which has a lower SES on average) removes one of the advantages of staying on at the school. Before, the advantage of staying on meant that you got to skip straight from "year 8" to year 10 and finish a year earlier, which you couldn't do if you went to MHS or MacRob for example. Now though, that option does not exist, so there is less of a reason to stay on at the school and not move to MHS or MacRob.

Sometimes I wonder if the school had another motive for changing the system. Was it to try to lift up the proportion of 40+ (top 9%) study scores in their statistics? I'm not sure if it was a reason, but if it was, then it was not really to the benefit of the students who could have started their bachelor degree a year earlier.