February News Highlights

Welcome to my first round-up of science news that has caught my attention in the last month (February 2021). I’m planning to make this a regular feature, covering three to five news articles. I’ll provide a link to the article and to any relevant scientific papers, where available.

First up this month is a Covid-19 related story discussing the potential for creating mRNA vaccines that don’t need to be stored in specialist freezers. Biopharmaceutical company Curevac have a vaccine currently in trials that they are confident can be stored at normal refrigerator temperatures (2 – 8 °C) for 3 months and could be kept at room temperature for 24 hours. The BioNTech/Pfizer vaccine is also undergoing storage stability studies at fridge temperatures. A team at Imperial College, London is working on an RNA-based Covid-19 vaccine that currently seems to be stable for up to 50 days at room temperature – they found this out when they couldn’t access their lab during lockdown! The Imperial team has been using ionic liquids, which are salts that are liquid at any temperature, to stabilize the RNA.

But what about tropical regions, where “room temperature” is much hotter than here in the UK? Other vaccines have been given approval for storage at much higher temperatures,

Vaccination (Credit: UNICEF Ethiopia (CC BY-NC-ND 2.0))

such as a meningitis A vaccine that can be kept at 40 °C for up to four days. A joint University of Bath and Newcastle University (amongst others) research team are working on developing heat-stable versions of the childhood vaccinations that we take for granted in this country. The method the team is using is to encapsulate the vaccine proteins in a “cage” of silica (the building blocks of sand or glass) before drying. In the case of the tetanus vaccine, this approach has been shown to protect the vaccine even when heated to 80 °C for two hours – there are still hurdles to overcome in terms of getting the vaccine back out of the cages in medical settings, but the technique definitely shows promise.

News article link: https://www.chemistryworld.com/news/can-chemistry-thaw-the-vaccine-cold-chain/4013049.article

Related link: https://www.who.int/immunization/newsroom/press/19_02_2014_meningitis_vaccine_outside_cold_chain/en/

Scientific paper: Doekhie, A. et al., (2020). Ensilicated tetanus antigen retains immunogenicity: in vivo study and time-resolved SAXS characterization. Sci. Rep. 10, 9243, DOI: 10.1038/s41598-020-65876-3

And now for something completely different… Researchers from Purdue University in the USA have trained pigs to use joysticks – although they aren’t as good at it as primates like chimpanzees or rhesus macaques. The research team used operant conditioning, where animals learn that performing an action gets them a reward, to teach the pigs to manipulate the joystick with their snouts and make a cursor hit a wall on screen – successfully hitting the wall with the cursor earned the pig a food treat. Fascinatingly, the pigs even worked out strategies for moving the cursor to walls that they couldn’t reach just by a simple push of the controller. They were, however, limited by what they could do with their snouts and also by their range of vision, leading the researchers to suggest that touch screens may be more appropriate for this type of training.

You may be wondering what the point of all this was. Surely the scientists didn’t just want to see if a pig could move a joystick? Actually, computer-based “games” are commonly used to investigate the cognitive capabilities of a range of species, from pigeons to great apes. Using computer tests can be more objective than testing by humans – in this case, the pig either hits the wall with the cursor or it doesn’t, allowing statistical modelling to determine whether the number of times they do it is better than could be achieved by chance. The reason pigs are being tested in this way is that interest in understanding the cognition and intelligence of farm animals has increased with greater public interest in the ethics of keeping animals. An awareness of the intelligence of animals like pigs could lead to better management and husbandry of them in farm settings.

A pig out on pannage in the New Forest (Credit: Stephanie Powley) - if you'd like to find out more about this custom, check out Wildlife Online's post on the subject.

News article link: https://www.theguardian.com/science/2021/feb/11/pigs-can-be-trained-to-use-computer-joysticks-say-researchers

Scientific paper: Croney, C. C. & Boysen, S. T., (2021). Acquisition of a Joystick-Operated Video Task by Pigs (Sus scrofa). Frontiers in Psychology. 12, 142, DOI: 10.3389/fpsyg.2021.631755

Many people are aware of the problems with plastic use, from their oily origin to microplastics in the oceans, and lots of us are trying to reduce our reliance on plastics, especially single use ones. Some plastics can be recycled, but the resulting products are often lower quality than the original plastics. The best way of recycling to give high quality results is to use chemical recycling, where the plastics are broken down using chemical reagents, but this is not always easy to do and can require harsh conditions. Now, however, a team at the University of Groningen, in the Netherlands, has developed a method of producing plastic polymers and chemically recycling them from a naturally occurring molecule called lipoic acid; the polymers created being suitable for a whole range of

Jackdaw with plastic litter (Credit: Stephanie Powley)

plastic uses. Lipoic acid is found in a range of foods, from liver and kidneys to broccoli and yeast extract and the technique that the research team has come up with could be an important step towards “circular” plastics – where the item can be recycled over and over so no new oil-based plastics need to be produced and no waste ends up in the oceans. It will be interesting to see how this idea progresses over the next few years.

News article link: https://www.sciencedaily.com/releases/2021/02/210204144101.htm

Scientific paper: Zhang, Q. et al., (2021). Matter. 04 Feb, 2021. DOI: 10.1016/j.matt.2021.01.014

I’m an analytical chemist and also a fan of crime mystery TV shows and books, so that this next article caught my eye is perhaps not surprising. If you’ve watched a TV show like CSI or one of the many true crime programmes that are in the schedules, you’ll probably have seen forensics teams spraying a chemical called luminol at crime scenes to look for the presence of blood. Luminol reacts with the iron in the blood’s haemoglobin to luminesce, producing a blue glow that can be seen in low light conditions. What luminol can’t tell forensic scientists is whether the blood present is from a human or another mammal species; that requires further chemical testing in a laboratory.

A team of researchers from the University of Albany in the USA have now developed a method of determining whether a blood sample is human or not quickly and easily at a crime scene, a particularly useful process for hit-and-run incidents where knowing whether a person has been involved in the collision is essential. The method developed uses a type of

Caution, wild animals road sign (Credit: Marc Baldwin)

analysis called attenuated total reflection Fourier transform-infrared spectroscopy (ATR FT-IR), which looks at how the sample absorbs light in the infrared wavelengths – for this application, the area of interest is the mid-infrared with wavelengths of 2.5 µm to 25 µm, also determined as a spectral range of 4000 cm-1 to 400 cm-1.

The scientists have shown that human blood absorbs differently to non-human mammal blood, when a genetic algorithm is applied to the spectra, meaning that a portable test taking only a few minutes could be easily used at crime scenes to differentiate between human and non-human blood. This method also doesn’t seem to give false positives for human blood from samples actually supplied by ferrets, an improvement over some current techniques. The team of researchers say that some further development is required to ensure that the method is effective for blood samples from a range of surface types, but this is a promising technique for fast, reliable analysis of blood samples in the field.

News article link: https://www.chemistryworld.com/news/rapid-test-can-tell-human-from-animal-blood-at-crime-scenes/4012897.article

Scientific paper: Mistek-Morabito, E. & Lednev, I. K. (2020). Discrimination between human and animal blood by attenuated total reflection Fourier transform-infrared spectroscopy. Commun Chem. 3, 178. DOI: 10.1038/s42004-020-00424-8

That’s all for this month, check back next month for some more science news and if you see any news articles you’d like to share with me, please get in touch.