Author: David Bradley

Orders of magnitude

Strangely, the phrase “orders of magnitude” featured in a visitor’s search efforts while browsing the sciencebase site. Unfortunately, other than using the phrase myself in the context of, for instance: “the amount of greenhouse gases emitted by human activities is several orders of magnitude smaller than those emitted by natural processes”. I did not actually have a definition of orders of magnitude on the site. Until now. So here goes:

The order of magnitude is the scale of any given amount where each class contains values of a fixed ratio to the class preceding it. The ratio most commonly used is 10. For example, a kilogram is three orders of magnitude bigger than a gram.

In the greenhouse gas instance cited above, the phrase “orders of magnitude” is simply being used colloquially and can apply in many situations, such as the volume of water in the Pacific Ocean is many orders of magnitude greater than that contained in Lake Michigan. To give a more solid example, one might say “An order of magnitude difference between two values is a factor of 10. For example, the mass of the planet Saturn is almost 100 times that of Earth, so Saturn is two orders of magnitude more massive than Earth.

Orders of magnitude are not always on the decimal scale. For instance, the difference in size between a megabyte and a gigabyte is three orders of magnitude, but the multiplier is 1024 rather than 1000. Please correct me if I’m wrong on that, I guess you could define a single order of magnitude her as being based on 1024 rather than “10”.

More on order of magnitude here.

Intelligent materials protect sports lovers

An intelligent plastic that is so flexible when left to its own devices while flow like a very slow moving liquid, but hit it with a hammer and the intelligent molecules form which it is made stiffen up instantaneously and absorb the energy of the blow. Such a polymer has been incorporated into textiles and clothing to create lightweight and flexible body armour for high-impact sports and other activities to save users from serious impact injuries. The polymer and textile-embedded material was the brainchild of UK company d3o, which has recently worked with a sports clothing manufacturer to develop a range of protective gear.

There was a video that demonstrated how to protect a falling egg using this material. This would make an excellent science fair project: compare different packaging materials for protecting eggs – cardboard, polycarbonate, d30 intelligent material. Unfortunately, the vid is no longer available.

The smart material is made up of a matrix of polymers with tiny pockets filled with a fluid. In normal wear, the material moves freely with your body movements but if you take a dive, the intelligent molecules in the fluid stiffen in less than a thousandth of a second, which makes them absorb the energy of the impact It works because under normal conditions, the polymer molecules move and slide across each other, but when they are put under rapid shear stress in an impact, for instance, the polymer molecules immediately form cross-links with one another and the material stiffens to take the brunt of the impact. Once the force is removed, the polymer cross-links are disengaged by further low force movements and the material reverts to its flexible state.

Power up your genome with chemistry

Post-genomic scienceResearchers have developed several tools to help them exploit the underlying chemistry of genomics, while novel chemistry has enabled faster, parallel sequencing methods that not only accelerate genomic research but also cut costs. The very same techniques allow sex chromosomes and complete genomes to be decoded faster and more cheaply than ever before.

Concomitantly, microfluidics technology is improving the way conventional fluorescence chemistry can be exploited in sequencing. Improved understanding of nanoscale channels – both synthetic and protein channels offers the possibility of studying individual biological macromolecules and microfabricated microarrays are opening up massively parallel opportunities. Novel chemical technologies are also opening up locked nucleic acids as well as non-DNA molecules such as microRNAs.

The so-called post-genomic era put the molecular smack in the middle of the biological quarter. Now, as cross-disciplinary communication matures, research at the intersection of chemistry and biology is working harder than ever to solve fundamental questions in science and medicine.

You can read the complete feature on the subject of chemistry in the post-genomic era from David Bradley in Science magazine today. It is the lead article on the Science Products page.

Anorexia and Kidney Disease

Anorexia nervosa is a serious and potentially fatal eating disorder usually characterized by a severely reduced appetite and often a total aversion to food. In the mainstream media, it is most commonly associated with teenage girls and the celebrity quest for a “size zero” figure. However, it is a serious and life-threatening disorder that goes far beyond the realm of body image and extreme dieting. Important clues as to the underlying causes of this disorder may be found in its association with chronic kidney disease.

According to Peter Stenvinkel of the Division of Renal Medicine, Karolinska University Hospital at Huddinge, Sweden, anorexia is observed frequently in kidney dialysis patients. The condition worsens as kidney disease progresses leading to severe muscle wasting and malnutrition, with all its associated health problems. Scientists had suggested a link to defective central nervous system control of appetite, so Stenvinkel and his colleagues have done an analysis of various biomolecules, including natural inflammatory compounds and sex hormones. Their results suggest that inflammation is closely linked to the development of anorexia in kidney patients and is more common in men than women.

Read the full story in today’s SpectroscopyNOW.

Frogs legs and AMPs

Antimicrobial peptidesSolid state NMR is unlocking the secrets of compounds found in natural membranes from frogs’ legs to human lungs that could lead to an entirely new class of antibiotic drugs. The compounds in question are antimicrobial peptides (AMPs) and they have been detected in every living creature studied so far. AMPs act as a first line chemical defence system in a huge range of organisms and could provide a novel approach to defeating drugs resistance in bacteria.

“Our overall mission is to use the kind of basic physical data we obtain from NMR to help interpret biological functions,” team leader Ayyalusamy Ramamoorthy of the University of Michigan explains. As with most discoveries of this nature, it will be several years before any clinical trials for specific health problems or diseases are complete. “How it works against viruses are under investigation in other labs,” Ramamoorthy told me.

You can find out more about AMPs as the front line defenders in the latest issue of SpectroscopyNOW.

Are you at risk of diabetes

Diabetes testBoth the UK and US national diabetes organizations have a risk test available for anyone worried about diabetes risk. Read the rest of this post and then take the tests and let me know how you get on.

You can take the Diabetes UK MeasureUp two-minute test here and/or the US diabetes risk test, although I recommend the more comprehensive (but more complicated) Diabetes UK test.

The US test is very, very simplistic, it asks you to plump for a very broad age range, asks if you have siblings or parents with diabetes, gets your height and weight, and whether you excercise or not. There is no detail in the questions at all, but then the results are very simplistic too. I truthfully filled in the blanks and scored a big fat zero. Null points. Thankfully, that means very low risk. But, I think the lack of questioning about supine waist measurement, body fat percentage and actual details about exercise, blood pressure etc, mean one would have to take this result with a large pinch of salt (actually, hold the salt, throw some sand instead, it is healthier).

I realize this is more about awareness and the tests are deliberately simplistic so that someone with a family history who does not exercise and is overweight might hopefully visit their doctor for a check up when the test shows them to be high risk.

There are over 20 million people in the US with diabetes, says the ADO, and almost a third of those (more than 6 million people) do not know it. These people need to get equipment and help for their disease like a glucometer by Dexcom.”

In contrast, the UK test is much more comprehensive and so presumably provides a better reflection of risk, it asks for waist measurement as well as ethnicity, and whether you have any cardiovascular disorders in some detail. It also asks about mental health and known metabolic disorders, as well as factors such as mental health problems. With all this additional information I still came out low risk, so I’m happy. What about you? I’d be interested to read comments from Sciencebase visitors who try either or both tests. Remember though, that if you are worried about diabetes or show any symptoms of the disease get to your GP fast.

Further information on diabetes is available from American Diabetes Association and Diabetes UK

Let’s Get Physical, Right Now

The latest issue of the monthly Spotlight column over on the physical sciences section of Intute is now online, this time featuring research from the earth sciences, the greening of chemistry in the developing world, and humans acquitted over Neanderthal extinction.

Cassava by David MonniauxChemists go veggie

Chemists working on tight budgets in developing countries may be able to swap flasks of laboratory reagents for extracts of celery and potatoes, or cassava and carrots and other inexpensive, …

Neanderthals more than severely put out by bad weather

Climate change saw off the last of the Neanderthals from their final stronghold on the Iberian peninsula thousands of years ago, according to …

Slumbering Yellowstone snores

Beneath the beautiful Yellowstone National Park in Wyoming lies a slumbering giant, a supervolcano who wakes every few hundred thousand years and wreaks havoc across hundreds of …

Viruses Do Not Eat Spaghetti

BacteriophagesThe faint glow from a single molecule combined with a stretch from “magnetic tweezers” could help scientists get a grip on how viruses that infect bacteria, so-called bacteriophages pack up their DNA. The research could lead to a resurgence of interest in the West for a potent treatment for infection that uses bacteriophages instead of antibiotics to attack disease-causing bacteria. The treatment side-steps the problem of bacteria evolving resistance to antibiotics because the agent of bacterial death can evolve just as quickly to cope with any defences put up by the bacteria.

In the face of deadly emergent bacteria such as Escherichia coli O157, multiple-resistance Staphylococcus aureus (MRSA) and Clostridium difficile, there is renewed interest in this alternative to antibiotics. The same study might also lead to new insights into how to combat viruses that infect people too, including herpes and adenoma viruses.

Many viruses use a self-assembly stage in which a powerful molecular motor packs their genetic code into the viruses’ preformed protein shell, its capsid. Now, Carlos Bustamente and colleagues at the University of California, Berkeley, have demonstrated that the genetic code is not coiled up like so much spaghetti on a fork but is packed using a concertina type approach. You can find out more about the details of this work in the current news round-up on SpectroscopyNOW.com

People caught pubic lice from gorillas

GorillaNo, it’s not some kind of deviant gorillas in the mist story, apparently, millions of years ago our ancestors picked up pubic lice (crabs) either by sleeping in gorilla nests (without the gorilla) or through eating our silver-backed cousins. David Reed and colleagues at the University of Florida publish details of their findings today in BMC Biology journal.

Reed is quick to point out that there was no monkey business between gorillas and humans. Of course gorillas are apes not monkeys, but this would be a perfect story for Ricky Gervais podcast star Karl Pilkington. “It certainly wouldn’t have to be what many people are going to immediately assume it might have been, and that is sexual intercourse occurring between humans and gorillas,” Reed says, “Instead of something sordid, it could easily have stemmed from an activity that was considerably more tame.”

Reed suggests that 3.3 million years ago, gorilla lice took up residence in the pubic region in our ancestors, this was probably around the same time that evolution took us from a fully hirsute state to our current nakedness. With no hair on our bodies other than the head and pubic regions, the lice would have been hard pushed to linger anywhere else.