1

Plant Sciences, Zoology & Evolution / Re: How do bacterial species compete and evolve side by side?

« on: 17/09/2021 13:34:31 »

This is an interesting read, relevant to the discussion: https://www.thenakedscientists.com/articles/interviews/modelling-microbial-public-good

2

Radio Show & Podcast Feedback / Re: Can 2 light rays collide - podcast available 28/08/21

« on: 10/09/2021 12:33:16 »

Thank you.

3

Geology, Palaeontology & Archaeology / Re: What is this lumpy rock found at Lyme Regis?

« on: 15/08/2021 21:48:09 »

Intriguing. No one seems to know what this is! It's a mystery... Twitter was relatively subdued on the subject, and normally that lot get to the answer in a jiffy...

I see. That's where you get your answers these days is it Chris?

We have 50k followers on Twitter. Among them are some highly qualified specialists who know other highly qualified specialists. Twitter is an ideal venue to seek counsel on certain subjects.

4

Just Chat! / Re: Questions pertaining to Notifications on TheNakedScientists.

« on: 31/03/2021 13:10:15 »

Thanks for your observations and feedback on this; but would you mind, in future, conducting these sorts of conversations on the Just Chat board. TY

5

General Science / Re: Does pressure in a thermos flask affect the temperature of the water inside?

« on: 22/03/2021 09:48:56 »

Nice question. I'd say yes, a bit.

The headspace gas above the hot liquid will be under pressure because heat from the fluid and the walls of the flask will heat the gas. When you open the lid, you release the pressure and the gas expands. This will drop the temperature of the gas and hence also rob some energy from the liquid because the gas has surface contact with the interface. But the effect will be very small.

6

COVID-19 / Re: How can vaccines claim to work against the new variations?

« on: 20/01/2021 20:53:38 »

Researchers are tackling this in several ways. The most obvious is that they take samples of the mutant viruses, mix them with antibodies made by people who have been vaccinated and then test if the viruses can still grow in culture. If they can, they've evolved beyond the protective effect of the vaccine. The second approach being used is to engineer the changes detected in the mutants into viruses grown in the laboratory to test individually whether the changes affect the immune recognition of the viruses. The third way is that scientists make models of the virus and alter them to reflect the mutations and look at how this changes the shape of the virus and by how much.

So far, these sorts of experiments are suggesting that the immunity conferred by the vaccine will still be protective against the viral variants.

7

Geek Speak / Re: One less reason for hanging onto windows 7?

« on: 06/01/2021 12:17:43 »

- Time to upgrade, I'm afraid...

@evan_au is absolutely right, and this has never been more critical than now with so much of our lives moving online and such heavy reliance on IT; online crime now massively outpaces traditional "street" crime in value terms, and old, vulnerable software is easy to target at mass scale and low cost / risk for malicious actors.

I would strongly urge you to upgrade - it's still free to do so.

Or switch to linux, which is always free, much safer and actually allows you to control your computer properly when you want to...

8

COVID-19 / Re: Anyone know the details of the new coronavirus variant?

« on: 23/12/2020 09:04:16 »

UPDATE 23/12/20

The mutations identified in the new variant have been documented in this paper: https://virological.org/t/preliminary-genomic-characterisation-of-an-emergent-sars-cov-2-lineage-in-the-uk-defined-by-a-novel-set-of-spike-mutations/563

This is a screenshot of the reported changes:

COVID-MUTATIONS.JPG (59.66 kB . 511x621 - viewed 10759 times)

Current questions surround the suggestion, made by epidemiologist Professor Niall Ferguson, that the agent might be better at infecting children. This is speculation at this time and requires further analysis and biological confirmation. I'll address this question, and the argument that an immunocompromised patient with Covid-19 might have been the origin of this new variant, in my next post.

9

Geek Speak / Re: Windows 7 full version or original?

« on: 10/09/2020 19:09:13 »

Get the proper - trustworthy - impression from MS - use the create install media system:

https://www.microsoft.com/en-us/software-download/windows7

You can input your key; it will release the software if the key's valid.

10

COVID-19 / Re: Could the infection rate be significantly underestimated?

« on: 17/04/2020 16:19:00 »

It's highly likely that infection rates are higher than we thought or think. Partick Vallance (UK chief scientific officer) suggested at one point that the ratio of deaths to actual infections might be close to 1:1000; so with 10,000 plus deaths there may well have been 10 million cases in the UK already.

What will solve this is widescale serological testing. Once we can test the UK at scale for antibody to infection and discover how many people have really had it, we can refine and reinforce our models and control measures accordingly. Personally, I suspect that there has been considerable widescale spread in the community already.

11

COVID-19 / Re: Is there modelling of the consequences of wards cleared for Covid-19?

« on: 17/04/2020 16:15:58 »

This is Chris Whitty's "secondary deaths" which are health consequences not directly caused by Covid-19 but instead indirectly linked to it. For instance, people having a heart attack who cannot get to hospital because all the ambulances are tied up being decontaminated after ferrying Covid patients to A&E. Also, people with planned treatments judged too risky under the circumstances may find their therapy deferred and they are forced to accept less than gold-standard treatments.

Is this happening? Yes. Do we have evidence? Not yet, but I suspect it will be accruing. For instance, a cardiologist friend reported that his presentations and case load for heart failure and stroke had plummeted. But this does not mean people have suddenly stopped having heart failure, they are instead deteriorating in the community, too fearful to come to hospital. The result may be people who go beyond the point of no return and cannot be rescued back because they present too late when they eventually are seen.

12

COVID-19 / Re: Why ventilate covid patients in a prone position?

« on: 13/04/2020 22:20:03 »

I'm very grateful to my friend and colleague Dr Ari Ercole, from Cambridge University / Addenbrooke's Hospital, who provided this extremely clear explanation:

As far as proning is concerned this has gone back years with nobody finding a survival benefit (although it improves oxygenation) until the attached study¹ which changed things suggesting it was a good idea if you do it early in ARDS and combine it with modern ventilation strategies which try to protect the lungs from mechanical trauma.

The way it works is through improving V/Q [Ventilation / perfusion] mismatch. Under normal circumstances, gravity means that the lowest (or back if you’re lying down) bits of the lungs tend to get a little more blood flow because the blood pressure decreases with height above the heart. At the same time, the low bits tend to be mechanically collapsed (think holding a damp sponge by a corner- the top is stretched and the bottom squashed). This means we tend to see collapse, pulmonary oedema and consolidation mostly on the lower (/back) bits of the lung. So we have an unfortunate situation where the blood is preferentially going to bits of lung that aren’t aerated very well (although hypoxic vasoconstriction may partially offset this).

Proning reverses that and sends blood to the aerated bits / re-expands collapsed lung. Unfortunately it’s not easy- very hard and dangerous to flip someone critically ill on a ventilator over (risk of accidentally pulling out the endotracheal tube, lines etc). Also there’s a risk of pressure sores and the facial oedema you see is marked. So we usually prone for 16 hours out of 24 or so. A lot of hospitals are putting together ‘proning teams’ because it needs a lot of skilled manpower.

1. Prone Positioning in Severe Acute Respiratory Distress Syndrome, Claude Guérin et al., NEJM 368 p.2159

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Just Chat! / Re: What are you doing in quarantine?

« on: 09/04/2020 19:51:11 »

I heard you started posting spam. But I might be wrong...

14

COVID-19 / Re: How do the Imperial modeling vs Oxford papers compare?

« on: 30/03/2020 17:00:39 »

The modelling paper from the Oxford group makes a large number of assumptions about the homogeneity of the population and the way the agent incubates and spreads. The result of their modelling is a prediction that as many as 50% of the population have already been infected.

This seems extremely unlikely. If the assumptions it makes were true, it's a mystery why America, extremely well connected as it is, is only just now joining the party; the virus would have spread there and delivered big numbers much sooner than it actually has. It's also a mystery how so many people (half the population) could be infected yet there be no corresponding spike in deaths like that which we are now seeing and what has been witnessed in Italy.

On the other hand, the Imperial College paper by Neil Ferguson and his colleagues models how a new agent, to which the population is not immune, is likely to spread. They make various predictions of case numbers over time, and they model 2 control scenarios: mitigation vs suppression (what we are doing now) and ask how they compare in terms of case load.

It's the Imperial study that has informed the government's present approach. Today, the same group have now released a new paper that uses rates of death to back-extrapolate to predict the likely number of cases in 11 countries across Europe. This suggests that 43 million infections have occurred across Europe, 1.7M of them in the UK. This means that the attack rate of infection (the number of people infected as a proportion of the whole) is about 3% in the UK, but much higher in Italy at close to 10%.

They then forward extrapolate to predict how many deaths have been averted by the present control manoeuvres. The answer is an estimated 59,000 people across Europe, 400 in the UK.

They acknowledge that serological assays (antibody tests) are urgently needed to clarify this situation and test the validity of these predictions.

15

COVID-19 / Re: Is there coronavirus hysteria?

« on: 27/03/2020 18:23:54 »

I though they were bats (to eat them that is)

Ozzy Osbourne must be crapping himself...

16

Just Chat! / Re: Latest Forum Updates and Upgrades

« on: 24/03/2020 11:22:16 »

MARCH 2020 - CORONAVIRUS SPECIAL UPDATE!

Hello everyone. I hope that you are all keeping well and we thank you for your contributions to this forum, especially the moderators who do a wonderful job and all deserve our wholehearted gratitude.

Regulars may have noticed that we have taken the unusual step of creating a special new board to accommodate the enquiries we have been receiving about COVID-19.

We felt this was justified because this is a specialist topic that is generating a high volume of traffic and will be easier for us all to curate and browse with all of the posts gathered together in that venue.

Could I ask, therefore, that if you decide to start a new topic relevant to COVID-19, please use the above-linked board to post it.

Many thanks, and stay well!

17

COVID-19 / Re: Why is the coronavirus fatality rate in Germany so low?

« on: 21/03/2020 12:26:49 »

This is most likely to be a statistical artefact of the testing.

The Germans have tested a lot of healthier people, including a lot of people from ski resorts.

Fitter, younger people tend to go skiing; older people in poor health do not (they board the Diamond Princess). So although the detection rate is high, the risk of severe disease is low, giving the impression that Germany is somehow special.

18

COVID-19 / Re: Will pneumonia vaccination help to protect people who catch Coronavirus?

« on: 13/03/2020 12:43:24 »

Yes and no.

Pneumovax (or equivalent) triggers an immune response again the bacterium Streptococcus pneumoniae, which causes pneumonia as well as sepsis and meningitis. As such, it will not drive an immune response against coronavirus, so a pneumonia vaccine recipient remains susceptible, and you could catch coronavirus.

BUT - frequently, people who suffer viral pneumonia - classically caused by the flu, although other viruses are also available (!) - the damage to the airway defences caused by the virus renders a person more susceptible to subsequent so-called bacterial superinfection. This means a bacterial infection on top of the initial viral infection. Staph aureus is a common cause of this, and the pneumonia vaccine won't help against that, but some people may develop a Strep pneumo infection. If they have received the Strep pneumonia vaccination, this risk might be mitigated.

19

The Environment / Re: How does science contribute to the circular economy?

« on: 08/03/2020 12:09:21 »

The point of a circular economy is that you design materials from the get-go with their end-of-life in mind.

Hitherto, we have given precious little thought to what to do with things when they break or are no longer useful. As a result, we end up trying to retrofit a recycling plan to products once they have already accumulated into a problem.

20

COVID-19 / Re: Is viral pneumonia result of immune reaction or viral damage?

« on: 07/03/2020 22:36:19 »

Both.

Viruses are obligatory intracellular parasites, meaning that they rely on invading and hijacking our cells in order to replicate. When they do so, they usually compromise the cell, leading to its ultimate destruction. As such, viral infection leads directly to tissue damage; if this is in the lung, that's a pneumonia.

At the same time, viral replication in cells leads to the production of various cellular alarm signals called cytokines. These attract the immune system, which then sets about destroying virally-infected cells; but in the process it usually also causes bystander damage to adjacent healthy tissue. This is a pneumonitis.

Both phenomena will occur at the same time; usually the degree of damage is low, but in some cases it can be severe. The evidence we have is that the 1918 Spanish flu pandemic strain (H1N1) provoked just this sort of immune overdrive, leading to catastrophic lung damage, especially in people with healthy immune systems. This is, we believe, the main cause of death in these people.