Thanks for you question! I (Sandhya) am a biotechnologist (so expert in bioreactors) and stem cell engineer. I (David) very much have a background in biology – I did my undergrad in Applied Biology and a Masters in Stem Cells and Regeneration. I chose this project because I was keen to work with stem cells and bioreactors, and because I wanted to contribute to a project that could make a real different to people’s lives and wellbeing. I (Chan) am a (bio)chemical engineer (Chan) and although I had taken a few biochemical modules on how to produce biomass, cells, and proteins in a bioreactor, I had to learn the cell biology of RBCs and the biological process behind it. I have chosen this project because as a biochemical engineer, I enjoy optimisation and the production process, but I always enjoyed medical science, which triggered my interest in this project.

Thank you for the question, if blood transfusion is the current mode of treatment, then yes our researach will definitely be of help. In addition, for people requiring regular transfusions, the cells we manufacture would theoretically be better in terms of blood type matching and risk of immune rejected (also known as alloimmunization)

Thank you for the great question! It would definitely be cool to make extra efficient red blood cells that work way better than the naturally occuring ones! It would be a whole new area of research for blood biologists. However, as engineers, we are currently working with the cells that the biologists have developed and given to us, so the naturally occuring red blood progenitor cells and we are aiming to grow and mature them in red blood cells that would deform in the same manner (essential to allow them to navigate through blood vessels) and they bind and release oxygen in the same manner to naturally occuring ones in our bodies.

Thanks for the question! We currently work with red blood progenitor cells that will give rise to the universal blood type RBCs.

Thank you for your question! Bioreactor technologies are being developed for a variety of cell types and this is an area of active research. There are many challenges with growing any cell type outside the body including red blood cells (RBCs). We aim to manufacture RBCs to address the growing shortage of donated blood globally. Within the different cell types in blood, we are focussed on RBCs since they are the oxygen-carying component of blood and hence, if we can replenish them for a patient who has suffered major blood loss, we can save the patient's life and their body is then able to replenish the other cell types in the blood tissue.

We can manufacture RBCs using existing bioreactor technologies, but these technologies are not yet fully optimized for cost-effective manufacture. Our research focuses on optimizing these technologies (that were developed for other cell types) specifically for cost-effect mass RBC manufacture. Current cost of donated blood is ~£125/unit (it is >£500/unit for rarer blood types) while that for bioreactor-produced RBCs is >£5,000/unit. Our research aims to design better bioreactors to bring down costs closer to that of donated blood.

Thank you so much for your kind words and the great question! If we use the right starting cell type, we can theoretically produce any target cell type of interest. For instance, we use red blood progenitor cells, which are what we refer to as 'lineage-committed' - so they can only mature into red blood cells and not other cell types in the blood tissue. However, the technology we are developing could use any starting cell type from the blood tissue - so if we were to use haematopoietic stem cells (not lineage-committed), we could potentially produce other cell types in the blood tissue such as white blood cells and platelets.

Yes, absolutely! It is the key aim of using technologies such as the bioreactor. We start with a small number of stem cells or progenitor that have the capacity to divide and give rise to more stem/progenitor cells, under the right conditions. Once we get enough starting stem/progenitor cells, we then modify the bioreactor conditions to promote their maturation (also known as differentiation) to form red blood cells. Our research aims to identify these best conditions to grow and mature these cells within bioreactors, as well as the starting cell number and final cell numbers we can get from the bioreactor.

 Great question, thank you! It is both cutting edge and doable, however, currently it is expensive to mass produce them to be used in the clinic for blood transfusions. We can make a few millilitres in the lab, but existing technology does not support making 'units' of blood in a cost-effective manner (compared to donated blood costs). So you're correct - one of our key research aims is to design a 'bioreactor' technology that will make the red blood cell manufacturing process more efficient and hence cost-effective.

>This is very cool research that can impact so many lives! Thanks for the work that you do.
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>My question is: Is it possible to also differentiate stem cells to other types of blood cells like platelets and white blood cells?

Hello, thank you for the great question! The starting cell type, known as BEL-A cells (developed by scientists at University of Bristol) that we work with, have been succesfully matured into red blood cells that are similar to native red blood cells found in the body - their biological signature and performance (e.g. oxygen-binding capacity) are comparable. Our aim of designing 'bioreactors' to mass manufacture these cells will be followed up with a list of criteria that we will check against to make sure that our bioreactor-produced cells are comparable to native red blood cells.

Thanks all, my time's up. It's been a blast. Please feel free to leave some feedback here: https://www.menti.com/alsm1ao6jy3h/0

I'm an advocate for better ventilation in schools and workplaces. I think it could make a significant difference both in terms of reducing the spread of covid, but also other airborne diseases.

There is an argument which says some of the reduction in R is due to immunity build up through prior infections and as such we may not be able to sustain R<1 indefinitely. Personally though I would prefer to gain immunity through a regular safe and effective vaccine rather than through infection. It is certainly the case that reductions in transmission provided by ventilation would reduce the effective reproduction number relative to what it would be otherwise, taking the edge of the peaks of waves that we might otherwise experience.

I don't believe though that ventilation/filtration is a silver bullet which will end the pandemic on its own. I think it is a tool in a multi-layered protection strategy that we should be implementing which includes vaccination, improved sick pay, mask wearing in some settings, messaging and testing.

We wrote an opinion piece about this in the BMJ earlier this year: https://www.bmj.com/content/376/bmj.o1

Wow it's a fascinating question and one which goes beyond my expertise as I don't work in evolution.
As far as I understand though we already have several species of non-human animals which would be considered sentient, but to some degree it depends on your definition.

I'm certainly not at the forefront of these efforts, but we have scientists looking at all sorts of emerging threats. Bird flu, for example has been a popular potential candidate to make the jump from animals to humans and thence to have human to human transmission.

In the UK we have NERVTAG - The New and Emerging Respiratory Virus Threats Advisory Group for example.

I'm not really a fan of horror as a genre. The last film that I watched that you could even describe coming close to that category is "The Orphanage" directed by Guillermo del Toro. I enjoyed that one, but generally it's not my thing.

It's a great question.
That we had a pandemic of a respiratory virus I think was predictable and predicted. In that sense we should have been better prepared.
The exact timing and type of pandemic, however, is harder to predict.

Probably the best analogy is to earthquakes. It is almost impossible to predict particular earthquakes on any useful timescale before they happen, but actually we can characterise how frequently earthquakes of particular size happen in the long run. So while we can't prepare for a particular event we can prepare for generalities. In Japan, for example, they have an annual disaster preparedness day precisely because they are aware that the risks of earthquakes (and other natural disasters) there is high. In the UK, our relatively lower risk means that it probably isn't worth while to undertake these preparations.

Whilst each flap of a butterfly’s wings does change the air pressure around it, this fluctuation quickly dissipates and is incredibly small in comparison to the large-scale changes in air pressure which determine the weather. Within a few centimetres of a flapping butterfly the disturbance it causes will have been dissipated by the surrounding air molecules, making it difficult to imagine how the minute changes caused by butterfly’s wing flaps could be amplified fast enough to manifestly change the forecasted weather to the degree required to trigger or avert a tornado.

Those are great questions. I'm afraid I will have to duck the first one because that isn't my area of expertise. I primarily work in developmental biology/pattern formation and epidemiology.
That said, there are lots of really interesting questions about stability and robustness of eco systems, which can be tackled using tools similar to the ones I employ.

In terms of Ian Malcolm, I'm pleased to think a mathematician was important enough to be one of the few people who should be afforded a sneak preview of Jurassic Park. I think they could have worked a little bit harder on his explanations of the mathematics of chaos in the film.
I think the butterfly effect is perhaps one of the most misunderstood "popular concepts" in all of science. It's an attempt to explain the fact that chaotic systems (like the weather) are typically extremely sensitive to their initial conditions, but I think it's been misappropriated to suggest we can calculate the probability of a hurricane arising from any flap of a butterfly's wings, which is not possible.

Primate cognition is not my field of study. However, it is true that lemurs have less developed cognitive skills than other primates, such as apes. On the other hand, lemurs use sensory modalities differently than other primates - for example, their olfaction is much more developed than those of apes or humans.

To trigger male mating behaviour I soack cotton strips with the chemical mixture and put the strips inside the enclosure, so the lemurs can smell the odour (but avoid it if they find it unpleasent).

Sorry, I have never been in Skansen in Stockholm

No, unfortunately they don't host gentle lemurs

In addition to lemurs, I have also worked with cotton-top tamarins during my PhD work. I loved them!

Psychology is not my field of study, but clearly humans have much in common with other primates and so primatology can help us to improve our understanding of human psycology via comparative studies.

No, lemurs are not suitable as pets. For example in Europe it is illegal.