Author: _MikeNicoll

What follows is a practical guide to using Plickers in your classroom. I have included a link to example Biology question banks near the end of the article – once you have a Plickers account, click here if you’re just after those. 

1. You will require these (free!) things:

• An account on Plickers.com
• A printed set of Plickers barcodes for your class (from here, or the above site)
• The Plickers app on your phone (available on both Apple and Google platforms)

2. In class, I introduce Plickers as a way that we can “play” quizzes during lessons. I hand out the codes and get them to stick them on the back of their books (death to the scourge of loose sheets).

My general script to students (and rationale) is:

“These codes let you answer multiple-choice quiz questions, and because everyone’s codes look random, you can silently answer without other students in class knowing what you have chosen. This means you can honestly choose an answer, even if you think other people would disagree with you.”

This, alongside verbal reinforcement that you do not want discussion before an answer, means all students are free to tell you what they really think.

3. Students are not universally going to like that you need to scan the room with your phone to collect answers. You can use Plickers without making students uncomfortable though – the whole point is to make it easier for them to all tell you what they think. My general script is:

“To collect our answers, I will scan the room with an app on my phone. The app only scans your codes:

• It doesn’t take photos
• It doesn’t take video 
• But if you are at all uncomfortable with the camera pointing at you, that is completely fine. I still want you to share your answer with me, so simply hold your code in front of your head, and I will loudly tell the room when I have finished scanning.”

Reiterating the importance of their answers to me, whilst preempting any uneasiness, has led to 100% participation in my lessons.

4. The four sides of the student codes have a tiny A, B, C and D, so after projecting your prepared questions on the board, the students answer by simply turning their codes answer-side upwards. You need to check the students can actually use this properly before you ask them any of your questions! If they don’t know what they’re doing, the data you collect with be unreliable, and your decision-making will be hampered. I specifically have a practice question with “Hold your book up to give the answer A” to make sure everyone’s on the same page before using the codes properly. 

5. I have a range of work-in-progress Biology question sets: www.plickers.com/drnicoll (you will need a Plickers account first). If you follow a set, it will be made available in your account to use with your classes. These are live documents, so sets will be added and edited as needed in my department.

6. When you set up your classes on your Plickers account, you can upload your students’ names. This is useful if you want to review the data at a later time, but honestly, I have found the real impact of the platform lies in its use in class, and the discussions that follow from it – I don’t find I have the time to look through the results at a later time. You can see whether Alfie, Beth or Charlie got it right or wrong from your phone, live in class – you don’t need to make more work for yourself when setting everything up. Save yourself time and simply list your students as numbers 1-40, then copy and paste that into every class. Here’s a 1-40 ready for you:

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In the vein of making videos about interesting stuff I come across, the other day I stumbled across the story behind these five dots:

Not much to look at – but! – these dots, which are known as the EURion constellation, are interesting because if they exist on a piece of paper you’d like to scan or photocopy, the machine will refuse to copy the paper.

This is useful for two things:

• Pranks
• Preventing the copying of banknotes for money counterfeiting

In fact, the EURion constellation is very popular on banknotes! Here is a happy citizen, gazing with love at a shiny new £10 UK note, and sure enough, there’s a bunch of orange EURion dots on the left of the note:

I guess I’m pretty naive about how money is designed. Unless it’s something like the Euro ¹, I assumed that every country designed everything that went on to their banknotes. Wrong – because the EURion constellation crops up on a few other notes.

From the Wikipedia, these include the Armenian dram, Aruban florin, Austrian schilling, Australian dollar, Belgian franc, Bosnia and Herzegovina convertible mark, Bulgarian lev, Canadian dollar, CFA franc, Chilean peso, Chinese yuan, Comorian franc, Croatian kuna, Czech koruna, Danish krone, Djiboutian franc, Dutch guilder, Egyptian pound, Euro, Faroese króna, French franc, German mark, Hungarian forint, Indian rupee, Indonesian rupiah, Japanese yen, Kyrgyzstani som, Kuwaiti dinar, Macanese pataca, Malagasy ariary, Mexican peso, Moroccan dirham, Namibian dollar, Netherlands Antillean gulden, Norwegian krone, Polish złoty, Romanian leu, Saudi riyal, Singapore dollar, South African rand, South Korean won, Slovak koruna, Surinamese dollar, Swazi lilangeni, Swedish krona, Swiss franc, Thai baht, Tunisian dinar, Turkish lira, Ugandan shilling, United Arab Emirates dirham, United States dollar and Zimbabwean bond notes.

Phew.

So why am I not making a video about this? Weeeeeell, here’s the common sense.

What I wanted to do was make a video in which I would essentially have a slideshow of bank notes, zooming in to the constellations and highlighting five dots, possibly to the beat of something like Take Five, for any watching music nerds.

This would be cool because a) I could show you just how widespread this semi-secret symbol is, b) how some countries nicely use the constellation in their design, rather than the obvious “here are some dots” approach on the current UK notes, and c) it’d probably be more engaging than something like, say, a blog post.

The thing is – as I’d been thinking about, at length – governments across the world do not want you to make digital copies their notes.

They would like it if you didn’t include all, or even parts of, their notes in your projects. They even used things like, oh I don’t know, the EURion constellation to help to prevent people spreading pictures of banknotes.

The Bank of England has a whole page dedicated to the digital use of their notes, as well as a handy list of approved images which you can use without going to prison. You can also contact various countries’ banks asking for permission, but… that was never going to happen.

So in future, before embarking on a project, collecting the highest resolution images of as many of the world’s banknotes as I can find, scoping out free-use music in 5/4 timing and typing “counterfeiting banknotes” into Google enough times to get added to a watchlist, I will try to ask myself “is there any reason I shouldn’t make this?”.

HIV spreads like internet malware and should be treated earlier – UCL News – Published on: 2 Apr 2015

The reason we call nasty computer programmes ‘viruses’ is because their behaviour mimics the real thing – spread between individuals, make more copies of yourself and repeat. So it’s kind of glorious that we can flip this around and learn about the viruses that make us sick by studying their digital analogues.

Here a team from London, Oxford and Changsha (in China) looked at the role of ‘hybrid spreading’ – a phenomenon shared by HIV infection and computer malware such as the Conficker worm. These viruses both spread over long-distances (bloodstream / the internet) and between close contacts (between cells / between computers on a local network). And both are also extremely difficult to get rid of once the infection is fully established because local ‘pockets’ of virus can be difficult to eliminate¹.

The computer model the research team have developed suggests that to combat HIV infection in people, we need treatments that work effectively against both means of spread, and we need to treat earlier than we currently do. The team’s model may also provide a way of testing whether drugs are effective at stopping cell-to-cell spread; a measurement that is otherwise difficult to study.

During an infection, the cellular ranks of our immune system army fall into two different squads: Rhinos and Elephants. While the Rhinos’ orders are to charge headlong at the invader (on the double!), the Elephants have a more subtle objective: remember this enemy.

If you win the battle against the maraudering microbe, the brave and knackered fighters of Rhino squad are rewarded with “early retirement”¹, but the Elephants (actually called ‘Memory Cells’) live on and await a repeat encounter with the enemy. Should the bug come back, the memory cells rapidly turn Rhino and destroy the germ before it can so much as dig a trench.

When we vaccinate ourselves against an infection, what we’re trying to do is build up a squad of germ-specific memory cells without having to go through the pain of getting the disease the first time around. This is a miraculous medical tool – just look at the number of infections per year in the US before and after vaccines.

The problem with vaccines is that they are difficult² and time-consuming to develop. When a brand new virus species causes an outbreak in the future, we will need another strategy to stop its spread in the short-term: vaccines are for old foes, not the new disease on the block.

But an interesting project underway at the Defense Advance Research Projects Agency (DARPA) is aiming to give us rapid vaccine-like powers by transferring the immunological memory from a single person to everybody else.

To understand how it works we have to return to the memory cell squad of our army. Just like a regular army, the memory cells comprise separate units which attack at short or long-range. It is the long-range attackers, called B-cells, that are the focus of the DARPA project.

B-cells wage war by releasing sticky chemicals that plaster themselves on to specific microbes. When smothered in these chemicals the germ is prevented from going about its business and is painted as a target for destruction. If the chemical, called an antibody, sticks strongly to the right spot on the germ: hasta la vista, buggy.

Each of our B-cells is stuck in their way. When they’re growing up, they rearrange their DNA to try to make antibodies that stick better to incoming germs, and only those that succeed get the job. As the successful will only ever make one version of an antibody, we can look at the cell’s DNA, find the antibody’s genetic code and make it in the lab – no B-cell required. And this is where the DARPA project comes in.

As described in a story published on the website Fusion.net, the idea is to recover B-cells from survivors of disease (for example, people recovering from Ebola) and learn the genetic code for the best antibodies targetting the infection.

So far, so good. But the next step? Inject DNA containing the antibody code into the blood of uninfected people, where it will be taken up by cells in their body, decoded and used to start pumping out the antibody. Should these people then catch the disease, the bug doesn’t just have to worry about the regiments of the immune system, it has to worry about the armed civilian populace.

This plan is audacious, and there are plenty of reasons to be skeptical about its success. Even if you get to the stage where your cells are happily pumping out the antibodies, viruses can throw up a number of problems:

• they could mutate; changing shape so the antibody doesn’t bind any more
• if they spread directly between cells rather than being released out into the open spaces of your body, antibodies won’t have a chance to bind them (HIV and herpesviruses, for example)
• they may already have countermeasures against antibodies (again, herpesviruses)

But even if the plan didn’t work against everything, that doesn’t mean it won’t against any. And if it does work? That would be incredible.

Head over to Fusion for the full story, including much more on the technology of vaccination using DNA and the hurdles standing in the way of the technique’s progress.

Linked article: DARPA thinks it has a solution to Ebola (and all other infectious diseases) – Fusion – Published on: 18 Mar 2015

A day late, but a link longer. Here’s this week’s lovely links:

A live look at the AIDS virus – Science Magazine

So cool. Being able to image where a virus is hiding inside an infected animal or person is a big sci-fi-esque deal. Current bioluminescence imaging techniques, where the glowy-glowy genes of fireflies are engineered into viruses, are an excellent tool for studying virus spread in small animal models of infection. But what if you’re an AIDS researcher relying on larger animal stand-ins to study human disease? In this work, the authors used a system called immunoPET to see where simian immunodeficiency virus (SIV – a simian contemporary of the human virus, HIV) collected and spread inside live macaques. The system works by injecting SIV-specific antibodies into the macaques, which then lock on to the virus particles and stick to them. Cunningly attached to these antibodies are radioactive molecules that can be detected using a PET scanner (PET stands for Positron Emission Tomography, and is a fascinating medical tool). Thus, via the interface of antibodies, virology and PET combine to visualise the location and amount of virus deep inside the body. The work revealed unknown reservoirs of virus infection in the upper respiratory tract and could potentially act as an avenue for studying infection in people, though I’d guess that was some way off. Click through to see some great images of the work and more discussion.

Countries Reeling From Ebola Are Facing A Big Measles Threat – Buzzfeed News

Simply put: the current Ebola-afflicted countries had gotten complacent about Measles vaccination, had realised this and aimed to roll out large-scale vaccination campaigns – and then Ebola hit and ruined everything. The successful vaccination coverage in these countries is now way below where it should be. It’s also important to note that the same is true of other diseases. Western Africa would usually have a full anti-malaria campaign in action, but Ebola has wrecked the pre-existing healthcare infrastructure.

As an aside, this isn’t the first interesting science article I’ve read from Buzzfeed recently. Who knew it wasn’t just about the cats, lists and lists of cats?

Ebola survivors offer clues to body’s virus defences – Nature News

A small study has shed some light on the immune response to Ebola infection. The immune responses of four people treated at Emory University Hospital were assessed to understand how the human body combats the virus. Interestingly, the patients had strong T-cell responses to the virus nucleoprotein, which wraps up the virus genome. As our current vaccine attempts are targetted at driving an antibody response to the virus surface glycoprotein, this new information could help us develop a superior treatment against the virus. The big caveat to note is that these infected individuals received novel anti-viral treatment that could have interfered with the normal development of the immune response, and (of course) the sample size here is just four people.

‘Disease is no longer a problem’ claims deadly bacteria – The Guardian

All this talk about stopping Ebola, but has nobody asked the virus what it thinks? No: it’s just another form of discrimination. Whilst this is 99% political parody rather than microbiology, I couldn’t resist – a great article where pox virus stands in for a pox on the UK political landscape. Perfect.