Month: March 2012

Planetary landers, caffeine, sulfa drugs and chaperones

The latest issue of my SpectroscopyNOW column is now live. This week:

US researchers are developing the next generation of laser ablation technology, which might one day be used in a future planetary lander to carry out isotopic analysis of a planets surface, for instance, and so allow precise “geological” ages of samples to be determined. The technique, LAMIS, is not yet as sensitive or precise as mass spectrometry but has the advantage of requiring no chemical dissolution, sample preparation, vacuum chambers or laboratory infrastructure, a boon for a planetary lander. - LAMIS.

Spectroscopic information from samples of caffeine-containing drinks has provided researchers in Germany with the necessary data to determine whether a new test beverage contains natural or synthetic caffeine. The technique could let regulators check how well manufacturers of added-caffeine products are adhering to the rules regarding labelling products as “natural” with respect to the drink’s caffeine content. - Caffeinated caffeine.

X-ray diffraction has been used to pin down the mode of action of the sulfa antibiotics, which were first used 70 years ago. The work could provide clues to developing a new generation of antibiotics that would have fewer side effects and could stave off bacterial drug resistance at least temporarily. -  Sulfa drugs.

Researchers in the US have combined nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography to gain new insights into the way in which a member of the histone chaperone family of specialized proteins functions. The resulting three-dimensional structure of the histone chaperone Rtt106 and interactions could have applications under understanding gene silencing and the way DNA responds to damage. - Chaperones.

 

More red meat risk analysis

NHS Choices finally published its critique of the Harvard red meat research that had the tabloids screaming that meat kills earlier this week. I provided some commentary on Sciencebase soon after. Anyway, this is what NHS Choices concludes:

“This study had several strengths including its size, long follow-up period and detailed and repeated assessments of people’s meat intake. It also adjusted the results for other factors that might affect risk of mortality.”

However, the site also points out that the study was based on questionnaires. “…relying on participants to self-report factors, such as their meat intake through questionnaires, introduces the possibility of error, although the questionnaires were validated,” it adds.

One major concern, however, is that the participants in the study were mainly white health professionals, so the results may not be relatable to other populations.

NHS Choices adds that: “This study cannot prove that regular consumption of red meat ‘kills’.” The site points out that despite what vegans and others often claim, “Red meat is a good source of protein and certain nutrients such as iron, some vitamins and zinc.”

On the basis of a suspected increase in bowel cancer risk, the UK’s Department of Health advises adults who eat high levels of red and processed meat to reduce their intake to no more than 70 grams a day. I’d add to that the same kind of guideline they offer for alcohol consumption – moderation and not every day. Steak and ale every day is not going to be good for you…you can just tell, really, can’t you?

Can you see the Man in the Moon?

Moon photo by David BradleyQuite coincidentally, given the moon hour-by-hour video I posted earlier today, a press release just arrived waxing lyrical about gazing up at the night sky and seeing the familiar face of the “Man in the Moon”. The synchronous rotation of the Moon means it takes about the same amount of time to rotate on its axis as it does to orbit once around the Earth, which means the Moon’s “eyes” are always fixed in our direction, in other words the familiar hemisphere is always facing Earth. The “dark” side of the moon is not, as a matter of fact dark, it is frequently exposed to sunlight, it’s just that we don’t see it from Earth. But why was it the “facial” side of the Moon that ended up locked facing the Earth?

Oded Aharonson of the Weizmann Institute of Science, Peter Goldreich of Caltech and Re’em Sari of the Hebrew University of Jerusalem suggest it is not mere coincidence. The face faces us because it is low-lying and covered with craters. By contrast, the far side is predominately mountainous. “Intuitively, we might actually have expected the far side to be facing us as the high mountains, as opposed to the low craters, would have brought the Moon closer to Earth, putting the system in a lower energy state,” says Aharonson. Nature usually prefers lower energy states, so why isn’t this the case?

The motion of the Moon is a bit like the motion of a toy train circling around a track with two hills and two valleys. The hills and valleys represent the different energy levels of the orientation of the geophysically asymmetric Moon. Because of friction, the train continues to lose energy until it doesn’t have enough to climb over the hill, thus it settles into one of the valleys – facing Earth or facing away from Earth. The valley “chosen” is governed not by the depth of either valley, but by the height of the hill it had to cross to get there. In other words, when it ran out of steam it could no longer get over the “hill” and settled into the energy valley before that higher hill.

Processed meat, fillet steak and death

I was planning to write an “appraisal” of the Harvard study on meat and risk of death that hit the news today, but have been so busy procrastinating lately that another blog has beaten me to it. Apparently, we should all be eating less meat, particularly processed meat like sausages, bacon and burgers because not eating less will kill us. At least, that’s what the headlines and the tabloid stats seem to imply. 20% increased risk if you eat 3 or 4 beef steaks every week?

Sheesh!

Sounds scary. Better go vegetarian right away, which will be quite hard for anyone who actually does eat steak almost every day, I’d assume…

However, the risk of anyone in the 120,000 cohort studied by the Harvard team, dying in a given year works out at about 0.8%. In other words, on average over the course of the two decades-plus of the study, the risk of someone being “tracked” dying was less than 1 in a 100.

The study reports that meat increases the risk of dying by 20% (15-24%, for processed meat). Take that 0.8% as baseline and add 20% and the risk leaps to a massive 0.96%. So basically, still less than a 1 in a 100 chance of dying in any given year. Even stretching to the upper error bar in the study, the risk increasing by 24% still doesn’t take the risk above 1%.

None of this is to suggest that there aren’t health and environmental benefits to cutting down on one’s meat intake or indeed going wholly vegetarian, because there are. But, the way to convince people is not to spin the statistics in this way, but to hit them where it hurts, not in the heart, but in the wallet. Fillet steak 3-4 times a week? That’s quite a lot of yummy lentil burger equivalents…

Here’s the full skinny on those stats: Unpacking the meat data.

Carbon emissions and reproductive health

Is there a link between carbon emissions in the developing world and reproductive health?

High carbon emissions correlate with poorer reproductive health among women in nine countries of 74 assessed, according to US researchers. Conversely, economic development seems to have no significant association with female reproductive health.

FangHsun Wei and Vijayan Pillai of the University of Texas, in Arlington, explain that women’s reproductive health plays a crucial role in sustaining population health. This, they say, is because as women’s health improves they are more likely to make healthy choices and promote the health and well-being of their children.

The World Health Organization define reproductive health as “a state of complete physical, mental and social well-being, and not merely the absence of disease or infirmity, reproductive health addresses the reproductive processes, functions and system at all stages of life”. Moreover, the term reproductive health also implies that a person is “able to have a responsible, satisfying and safe sex life and that they have the capability to reproduce and the freedom to decide if, when and how often to do so.”

The researchers have looked at data on reproductive health, economic status and environmental factors for 74 developing nations across the globe in sub-Saharan Africa, The Americas, Eastern Europe and Central Asia, the Middle East, East Asia and the Pacific nations and South Asia. Carbon dioxide emissions from the burning of fossil fuels and cement production are used as a proxy of environmental degradation given that the activities that drive such emissions also generate pollutant issues at a more local level.

The team used statistical regression analysis to look at the effects of various causative factors on selected and well-measured outcomes: reproductive rights (reproductive rights scale), economic development (GNI per capita), social development (improved water source) and environmental development (carbon dioxide emissions) are independent variables, and reproductive health (RRI) is the dependent variable.

“The results of this study have implications for improving the conditions that are conducive to reproductive health of mothers and infants in developing countries,” the team asserts. They point out that the correlation between carbon dioxide emissions and poor reproductive health in the developing world (despite CO2 emissions being far lower per capita than in the US) implies that participation in global initiatives to develop renewable and sustainable energy sources and avoiding the use of fossil fuels will ultimately have beneficial effects on reproductive health as well.

Research Blogging IconFangHsun Wei, & Vijayan K. Pillai (2012). Environmental quality and reproductive health in developing countries Int. J. Sustainable Society, 5 (2), 146-159

The moon hour by hour for 2012

NASA GSFC Scientific Visualization Studio created this animation of the Moon, showing how its phases will wax and wane over the course of 2012. Time resolution is down to the hour. The tipping and rocking are a manifestation of the Moon’s elliptical orbit coupled with its tilt. The video is captioned with more detailed explanations of what you’re seeing. But, just watch, ignore the captions and the music. (Then watch again and read the captions).

Three minutes of exercise really isn’t enough

As promised, here are the thoughts of Soren Brage, an Investigator Scientist in Physical Activity at the MRC Epidemiology Unit in Cambridge on the recent BBC Horizon program featuring Michael Moseley taking part in a TV experiment to see how good high-intensity training (HIT) might be for his health.

“One could point out some obvious feasibility issues on implementing HIT at population level as well as perhaps exposing the issue of [an] n=1 [sample], lack of proper control, millions other things changing at the same time,” he told me and pointed out that such problems did not seem to deter the program makers from coming to “a strong conclusion appropriate for mass consumption issue!”

“In terms of the specifics of the HIT approach, however, it has been known for decades that not all calories are created equal and that high-intensity training (HIT) impacts on glucose transport via induction of GLUT4 (and although labelled as non-responder for VO2max, the show’s host improved his glucose metabolism dramatically),” Brage adds.

He asks, however, whether Moseley was actually a non-responder for fitness? “Well, for absolute VO2max yes but he managed to shift his work-oxygen uptake curve to become a more efficient machine and could produce more physical work at follow-up, hence fitter from that perspective. And did he lose any weight? And would you really train only 3×20 sec all-out to change your VO2max? I think the training literature (from the 90s, if I remember correctly) suggested longer intervals for endurance / VO2max was the optimal approach, so one would need to submit the host to that regime to truly label him as a non-responder – or accept that the definition of responding was just very narrow!”

Brage was also concerned that the discussion of genetics put the emphasis back on the old “blame-your-genes” story. He pointed out that if one was to make a more explicit case of not equating fitness with habitual activity and look at some of The MRC’s recent work (Sheng Xu, Tuomas Kilpelainen, Ruth Loos), then one might be quite encouraged to get up and do more activity, despite one’s genetics and perhaps even because one is a so-called non-responder with the worst possible genetic starting point.

Brage jokes that he allocated only 3 times 20 seconds for his assessment of the BBC Horizon program and so his thoughts are non-referenced and not systematically researched. He points out that perhaps therein lies another drawback of spending only minutes or seconds physical exercise at high intensity rather than running for an hour on Grantchester Meadows or in some other pleasant outdoor environment. “[There is] too little opportunity to let the thoughts fly and reflect on all aspects of life.”

The work Soren mentions has shown that higher levels of physical activity attenuate the affect of obesity associated alleles, highlighting that those at greatest genetic predisposition to obesity may have the most to gain by being more physically active:

Loos et al. PLoS Med, 2010 Aug 31;7(8). pii: e1000332

Loos et al. PLoS Med. 2011 Nov;8(11):e1001116. Epub 2011 Nov 1

Research Blogging IconLi S, Zhao JH, Luan J, Ekelund U, Luben RN, Khaw KT, Wareham NJ, & Loos RJ (2010). Physical activity attenuates the genetic predisposition to obesity in 20,000 men and women from EPIC-Norfolk prospective population study. PLoS medicine, 7 (8) PMID: 20824172

Three minutes of exercise is not enough

BBC Horizon recently discussed the recent burst of activity surrounding claims that just 3 minutes of very intense exercise (HIT high intensity training), done in 3×20 second sessions three times each week is enough to improve various health factors (such as insulin sensitivity and lung capacity).

The program’s presenter Michael Mosely is a medical doctor and on the basis of an MRI scan from a previous TV show that showed up to be a bit fat around his inner organs and some mention of his father having type 2(?) diabetes he wanted to try this exercise regime to see if it would work for him.

Apparently, it can sometimes be an uphill battle to get media interest in physical activity research as it is often seen as being more of the same and that people already know they should be exercising more. Indeed, just last week the National Health Service started promoting a 150-minutes a week exercise campaign. So, it’s interesting that the BBC should time this show to highlight this particular piece of research and so grab people’s attention. But, where was the context? They did include some sedentary behaviour research, but there wasn’t a lot of context regarding what is known about the field of physical activity and sedentary behaviour. There is a danger that people will go away thinking that a few minutes a week is all they need to do for exercise, or that if you are a genetic ‘non-responder’ as it turned out Moseley is, then there is little point in exercising at all, which is, of course, wrong.

The worrying thing about the show though is that they did two experiments with Moseley in parallel. They had him do the intense bursts regime for a month at the same time he was concentrating on walking more and not sitting at his desk continuously for hours on end every day. They said that during the experiment time that he was burning an extra 500 calories (kcal) per day because of being less sedentary. Then they told us that his insulin sensitivity had improved by about 23% but his lung capacity didn’t change at all (the non-responder bit). But, now there is no way to know whether that 23% improvement was down to him walking and fidgeting more and burning those extra calories each day or the intense burst regime. It could have been that it was the increased calorie burning that had that effect as his respiratory fitness didn’t change at all, as he wasn’t doing any substantial extra cardiovascular exercise. Mosely says that the regime goes against the medical received wisdom. It does, but does it stack up?

There really ought to have been some more information on all the other benefits of exercise (when done for longer). They claimed that personal exercise is like personal medicine and that there cannot be a one-size-fits-all approach to exercise. As if not responding to a drug because of genetics is somehow analogous it’s not. Even if it’s harder for some people to benefit from exercise, you honestly don’t ever see obese, fast marathon runners. Even if you’re a non-responder genetically, exercise comes with many more benefits than increasing VO2 max in some people. Cardio-respiratory fitness is just one aspect of health, physical activity is still really important for a host of other health benefits such as metabolic risk, weight management, maintenance of lean tissue, bone health etc, let alone the beneficial affects on mental well-being that come from exercise. Mood enhancement, normalization of circadian rhythms and stress reduction are just a few of the many mental health benefits exercise can have. Evidence is mounting for the benefits of exercise on mental health but psychologists are only now beginning to add it to their treatment regimes for their patients.

There was some suggestion that even if you got to the gym every day but sit at a desk for 12 hours you are somehow doing yourself harm. I suspect that much of that research has been hyped by the makers of standing workstations and treadmill desk attachments, to be frank. It would very disheartening to learn that my daily hour walking the dog and 2-3 trips to the gym each week are cancelled out by the fact that I work sat down at a desk much of the working day.

Thankfully, a paper just published in JAMA looked at the physical activity levels in 20,000 children and adolescents and suggests that being active may be more important than how much time you spend being sedentary. I hope they have a cohort to show that the same applies in adulthood.

The third aspect of the Horizon episode demonstrated that the brain has a cut-out switch that stops you exercising if your muscles tell you it might cause damage, i.e. pedal on a bicycle really hard for too long and it gets painful and your brain won’t let you continue. However, this isn’t a physical limitation and the threshold is set rather low for most people. Without causing actual damage it seems that you can workout through that barrier and get fitter still.

I will be following up this post with some thoughts from Soren Brage, an Investigator Scientist in Physical Activity at the MRC Epidemiology Unit in Cambridge. Watch this space.

This week’s (al)chemical happenings

The Alchemist learns this week how phosphorus atoms might be perfectly placed to build a quantum computer and how fluorescent gel and filter paper might put explosive sniffer dogs out of work. In environmental remediation the reverse of gold-digging could be used to remove toxic mercury ions from contaminated water while across the universe it could be that Earth-like planets are stuck between a rock and a hard place when it comes to chemical composition. In elemental discoveries, the possibility of making a pure, metastable “arsenic black” could be possible thanks to energetic calculations. This week’s award comes from Pittcon and is awarded posthumously to father than son Genzo Shimadzu, Sr. and Genzo Shimadzu, Jr. founders of the Shimadzu company famed for its analytical instruments.

The Alchemist Newsletter.

Rock on @GulliverTurtle

Gulliver Turtle was checking out my guitars and stuff yesterday, making sure I’d turned everything up to 11…there he is, third shelf up, on the right, next to my wife’s copy of Streitwieser & Heathcock “Introduction to Organic Chemistry” (2nd edn 1981) and just below the 1st edition of “A Brief History of Science”, which I co-authored with John Gribbin, Richard Dawkins, Ian Stewart and others back in 1998.