Dear Bellingen Shire,
Today is brought to you by the letters P and E.
First, Perfunctorily: no Covid19 cases in our shire – and still none found in the Coffs Harbour network. Within the State there is a huge amount of testing being done, and only a few cases Popping up in Sydney and Newcastle. However the surge of cases in Brisbane has put us on notice to not be cocky. It is really like looking for a needle in 50 haystacks. So this Presents a space to get a bit of science literacy, and leads to a question that has been forwarded.
A local citizen has asked : if rt-PCR testing is accurate only for DNA then why do we rely on it for Covid19 – which is an RNA virus?
There must be a meme going round. Up front, let me say that Reverse Transcriptase PCR , or Real time PCR, (2 similar but not the same terms) are actually very accurate and in fact expert colleagues assure me that it picks up RNA better than DNA. They are more sensitive than most available tests we have for viruses, quicker than a culture, and can be made Pretty specific. But no test is Perfect. Nothing is Perfect. Not our Parliament, our Priests, even Picasso.
We visited a Picasso museum in Barcelona a few years back and some of the great man’s stuff is just awful! But they made near Perfect Paella there!
But you may be falling asleep by now with all talk of DNA, RNA, PCR – terms a bit like Nabokov and Homer, Relativity and Tolstoy – like, everyone nods knowingly when they are mentioned, but hardly anyone has ever really read or understood.
So, to help start more knowledgeable conversations:
PCR means Polymerase Chain Reaction. Anything in Biochemistry with an “-ase” on the end is an enzyme. An enzyme is a molecule that when brought to a chemical mix which might want to react, but can’t get round to it, enables the reaction to go ahead with less energy and more quickly. But it is not actually used up in the reaction. A bit like an honest broker, or a good diplomat.
DNA means deoxyribonucleic acid. It is a Polymer – that means a long strand of little blocks stuck and strung together. DNA is like a ribbon with the 2 edges thickened up and then twirled and twirled and twirled until it bunches up on itself, and the bunches bunch up. But it is pretty stable. It is kept safe in parts of each of your tiny cells. When needed, a patch of the ribbon is uncurled, split by an enzyme, and then other enzymes bring a whole bunch of new blocks which match the part opened up. A bit like casting and moulding plaster or clay. The cast then –RNA – is a shorter, specific string and it moves into the rest of the cell to do stuff, make stuff , carry messages, make you.
RNA stands for ribonucleic acid. The trick of viruses is that they can get into a cell and take over all the cell mechanisms but dictate what the builders and workers do. Virus says “don’t make bone, or mouth lining or lung tissue just make a billion copies of me”. Instead of DNA, some viruses – eg Coronaviruses -have all their code on less stable RNA – hence an “RNA virus”. And hence a thing that is a bit more unstable, but quickly hijacks the cell, and can mutate a lot
So, in a sense, with PCR, we turn the tables a bit on the invader. Each organism has some stable and unique piece of RNA or DNA. So clever scientists make a little strip that mirrors and will stick perfectly onto that unique piece of DNA or RNA. We put it in a sample with the Enzymes. That copy gets replicated; the key bit gets bound, while the rest of the sample is washed away. This is done a bunch of times causing a chain reaction. So what was invisible to a microscope now is massive and detectable. So we have a Polymerase (the enzyme making Polymers) Chain Reaction.
It’s really pretty accurate. It is a bit technology intensive. But it is available. There is no reason to be concerned about its accuracy.
Another question to knock off easily is gas Perfusion. Some people are saying that wearing a mask will cause you to inhale your own carbon dioxide or carbon monoxide. Masks trap biological sized molecules. Gasses – ie oxygen you need and CO2 you also need – are much tinier and pass though relatively unimpeded. Studies have shown no drop in blood Oxygen levels while wearing a mask.
You breathe in about 21% of the air as oxygen but there is still about 16% still there in your out-breath , with some CO2. CO2 is really useful in your body. You may be surprised to learn that much of our drive to breath is measured on the CO2 level in blood and it is used as a store of essential acid and alkali to optimise your blood and tissue balance. But it is not trapped in a mask.
Now another E.
I’m going to lead off the science class and dabble a little more sombrely in the philosophical stream.
You cannot have missed the growing and intense discussion about a tide of mental health issues – especially in youth. This is a big deal and Everyone of needs to be thinking about who around you is having trouble in this very troubling of times. There are way too many contributors and precipitants to depression and deteriorating mental health for me to list them. I have mentioned before the excellent work by Professor Jakka’s team in Geelong showing that eating junk food (we all have an idea what that means) leads people to poorer mental health.
There is a lot of research, and a heck of a lot more judgemental opinions on why there is a wave of mental health issues. I just want to address one that is within Everyone’s reach.
I read somewhere that violent revolution is not a consequence of the oppressed rising, but of unmet Expectations. So too may be the sense of hopelessness, desolation, disappointment, loss, and powerlessness.
Expectations are not all bad. In my years working in outdoor education it was a key tool of unlocking growth in young people. We set high Expectations of them cooperating, overcoming challenges and surviving uncomfortable environments to come out feeling stronger, Enabled, Empowerred.
But Expectation can be corrosive. Especially when it is unrealistic, but a key marketing tool of holidays, consumer goods possession, looks, politics etc. “You can expect to have it all , now, as you want it, like the brochure!” It is also a dangerous mixed message when we are dealing with a once in a century global event. We need to set honest and realistic expectations to which we can all work and survive.
From the start of this letter I have been concerned by statements of “Snap back recovery”, “early marks”, “back to normal”. This is setting people up for disappointment. Perhaps it is healthier to acknowledge – as the experts who really study this stuff keep saying – this change in the world will be taking years to work through. It is a potentially big change. We don’t know how it will look in 2 years and some of the package that has been sold to our next generations as a given has changed.
However this is not all bad. The schools strikes, and Greta, and marches, tell us that in fact perhaps young folks Expectations have changed. Not all has been on a great path in the world. How about Encourage our youth, and 20- or 30-somethings, to think about how they would like to Expect the future to be. They are moving into the driver seat. But they will need to be agile, be ready to amend their Expectation. Seek wide Experience – not just the dream job.
The time to set new Expectations is now. Traditions are sometimes defined as an innovation that worked. The Schoolies bacchanal on the Gold Coast is not an age old tradition. It was manufactured in the last 30 years. I grew up there. Perhaps if we let go of that one, the Covid generation might create a new, better one.
To quote a lovely card we have on our fridge door:
“We cannot change the wind, but we can learn how to set our sails”
Dr Trevor Cheney
Please note the above is not scientifically referenced or attributed, as it is one perspective on science, learning, experience, and the Excessive Parade of data flowing past our minds. My apologies if someone has already said all the same things. We are Parallel, not Plagiarised. Please check with your own GP.