Author: David Bradley

Whenever there’s something “sciencey” on BBC Radio4 Today program, the interviewers never seem to ask any of the obvious “sciencey” questions about the subject. Today was no exception…

A Professor from Liverpool was suggesting could reduce Caesarean section rates by giving the expectant mothers, whose labour was not progressing, a drink of bicarbonate of soda. Apparently, blood around the uterus (or womb) was too acidic in these women.

I looked at this research which seems to have been published in June 2017 [https://www.ncbi.nlm.nih.gov/pubmed/28587493], not entirely sure why it’s suddenly on Radio 4 in January 2018. The paper does not talk about uterine blood acidity it talks about lactic acid (or rather lactate ion) levels in the amniotic fluid and that this is reduced by a tiny amount by ingestion of bicarbonate. Lactic acid is the product of anaerobic respiration that temporarily accumulates in body tissues and is the usual cause of a “stitch”. “Lactic” as sports therapists are wont to call it actually as a very short half-life and does not persist. The R4 interviewer should have known all that and could have probed that point!

She also said it was properly “blinded” and that the normal procedure is to give oxytocin to promote delivery. The women and the midwives would know that they were not prescribing oxytocin to those women given the bicarb. So, how was it blinded? She said the trial was small, 200 women (100 bicarb, 100 oxytocin), and that meant they could control for BMI. The obvious question is what was the statistical significance of such a small trial?

The Professor also pointed out that the effect was about 17%, so one in five fewer women in the group had to have a Caesarean than would normally be expected. That is potentially significant if it held up for a larger group but may well be a simple statistical blip and if they repeat with another 100 tomorrow they might find that one in five more has to have a C-section despite the bicarb.

Were the women being given any other drugs by mouth, the bicarbonate may have affected absorption from the stomach of those, we don’t know, the question wasn’t asked.

She said the hypothesis was based on the fact that they’d found uterine blood acidity to be high in women who had to have a Caesarean (but that’s not what the paper talks about and yet that’s how she framed it), and so the bicarb was meant to neutralize that. BUT and this is the big BUT. If you drink bicarb it neutralizes the acid in your stomach to some degree and forms bubbles of carbon dioxide which you belch away, basically. You cannot neutralize blood by drinking bicarb. Moreover, if you injected bicarb even into “acidic” blood, the body would respond by raising the acidity to compensate.

Blood is usually slightly alkaline, its pH lies between 7.35 and 7.45 and is tightly controlled by your body through homeostasis mechanisms. The contents of your stomach are rather acidic, pH is 3.5 or lower (this helps you digest food). Nothing you eat or drink can substantially alter the pH of your stomach (without causing serious harm, even antacids, like bicarb have a marginal effect). So, nothing leaving your stomach and entering the intestine or being absorbed directly into the blood will affect the pH of blood (this, by the way, is why all that alkali health diet stuff is nonsense [https://chriskresser.com/the-ph-myth-part-1/]). Indeed, although it is known that the level of carbon dioxide in the blood falls in pregnancy, the woman’s body compensates by buffering the blood to prevent it becoming less alkaline (more acidic) [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3952302/].

However, Mrs Sciencebase flippantly suggested that perhaps the bubbles produced by the bicarb were enough to propel the baby out!

These are just the obvious points that occurred to me on waking to hear this interview. Does nobody on R4 Today staff have any science training at all to be able to think of such points? Of course, they had far more important things to get on to, such as the sports results and the racing tips and Thought for the Day, so the interview was, as ever, woefully short and given a “Hmm” by Humphrys when it concluded.

Of course, Mrs Sciencebase may have stumbled on an interesting point, perhaps drinking the bicarb solution was sufficient to cause agitation and activity in the stomach that generated gas and that it was the increased movement here that indirectly led to increased uterine activity. Of course, it may just have been the expectant woman having to sit up to take the drink that was enough…who knows? Certainly not the R4 interviewer, because he didn’t ask any of the right questions!

You probably heard that there’s a new computer security threat out there. Well, actually there are two and between them, they affect pretty much every computer chip you might have whether in your PC, tablet, smartphone or other devices.

The first is Meltdown it is a hardware rather than a software (apps) vulnerability and is present in the computer chips made by Intel that have the “x86” architecture, which is pretty much every PC with “Intel Inside”. The bug could let a hacker gain access to everything on your system, logins and passwords, bank details, encryption keys, personal documents and photos. However, once exploits for this vulnerability are known it was likely that the major cloud providers such as Amazon Web Services (AWS) and Google Cloud Platform would be among the computers affected the worst (they have now been patched, I believe). ARM chips are affected by Meltdown to a lesser degree.

Microsoft and Linux providers have already hastily patched their “kernels” to overcome the Meltdown problem with Intel chips, so let your operating system carry out its updates urgently to stay protected. The Register describes the patching process as a requisite redesign of MS Windows and Linux.

Here’s how the site described its scoop on the vulnerability on Tuesday:

...a blueprint blunder in Intel's CPUs could allow applications, malware, and JavaScript running in web browsers, to obtain information they should not be allowed to access: the contents of the operating system kernel's private memory areas. These zones often contain files cached from disk, a view onto the machine's entire physical memory, and other secrets. This should be invisible to normal programs.

Unfortunately, for older Intel processors these patches will likely lead to a reduction in chip performance of up to 30%, which means your PC is going to run a lot slower than it did before this vulnerability was found and patched.

The other vulnerability, or should I say vulnerabilities, there are many, is referred to as Spectre. It is also a hardware vulnerability affecting Intel, AMD, and ARM chips. ARM processors are present in many of the world’s mobile devices and Internet of Things (IoT) devices from washing machines to smart TVs. In fact, Spectre affects pretty much every computer and smart device. It does not rely on specific features of the chip design present in Intel chips but works across all of them.

There is no single patch for Spectre. Specific vulnerabilities may well be addressed with operating system updates but this one is not going away any time soon. According to The Register, a malicious script on a web page could churn away using Spectre bugs to extract login cookies for other sites from your browser’s memory. “It is a very messy vulnerability that is hard to patch, but is also tricky to exploit,” the site says. Chip designers are likely to have to design out the bug in their hardware to preclude attacks based on Spectre.

The industry has apparently known about Meltdown and Spectre for at least six months and has spent that time spinning its public relations campaigns working on solutions to the problems. Oh, if you’re running an older version of Windows than Windows 10, there will be no patches (time to upgrade your OS). More information about who is affected on the BBC site.

At least one tech blogger has a slightly different take on the whole issue suggesting that as long as you allow your operating system to patch itself/update you won’t have any problems and the 30% performance hit will only arise in rare, special circumstances for very few users. Either way, here’s my general advice on security that applies regardless of what bug or vulnerability is currently in the news:

What should you do?

• Well, update your operating system in a timely manner as and when the providers release patches.
• Update your antivirus and firewall.
• Back up your data files now (should be done regularly anyway).
• Lock down what you allow your web browser to run in terms of scripts, use a noscript type plugin/addon/extension and disable Flash and Java and their ilk, this will break some sites but they are vulnerable, and always were, to security insults and malware anyway).
• Avoid downloading software/apps/executables from dodgy sites. If you must install software of unknown integrity use a sandbox/virtual machine to do so. (Google sandboxie for one of those).
• Use a password manager for your logins, make it use strong passwords, and keep its master password secret and offline. Log out of and exit your password manager when you’re not using it or if you plan to visit websites that might be suspect so that its keys are not retained in computer memory and so it is not running should someone get access to your computer while you’re not using it.
• Clear browser history and cookies every time you exit your browser or leave your computer unattended, this is an inconvenience, but means that someone in a shared office space or wherever, cannot harvest anything from you.