Month: September 2011

Particles pass light speed limit? – Those tiniest of particles known as neutrinos are generated by various physics experiments at CERN in Switzerland, the home of the Large Hadron Collider. But, now it seems CERN neutrinos are hitting detectors at the Gran Sasso laboratory 732km away a wee bit sooner than they ought to.

The implication is that they’re actually exceeding the speed of light, c, you know that upper limit on how fast anything can ever go? Is this the end of Einstein’s Theory of Relativity or just some even spookier quantum effect than anyone has seen before? Or is it a flickering artefact of Susskind‘s holographic black hole model of the universe? Who knows? The scientists certainly don’t seem to!

The true meaning of The Singularity – The true nature of Ray Kurzweil’s “Singularity” is not some army of post-apocalyptic robot overlords stomping and rolling across a nuked cityscape of wind-blasted rubble and skyscraper stumps zapping errant humans with noisy laser beams. It’s a world of smug electronic umbrella-stands, digital lawnmowers that unfriend you on Facebook if you pave your garden, and web-enabled sofas that refuse the dust-busting attentions of automated vacuum cleaners…

Yawning cools the brain – I’ve discussed yawning and why we yawn several times. Some say we yawn because we’re tired or bored, as some kind of social message, when CO2 levels are high, to get more oxygen into our lungs or maybe to equalise pressure in our heads. Now, a new theory from scientists at Princeton University suggests that yawning simply cools the brain.

Post-doc Andrew Gallup and colleagues have demonstrated that yawning frequency varies with the season and previously that rats yawn less when air temperature exceeds body temperature. Now, writing in the journal Frontiers in Evolutionary Neuroscience, Gallup suggests that the seasonal disparity implies that humans (tested in the desert during cold and hot season) might use yawning to regulate brain temperature. Similar disparity is seen with stretching that might imply stretching too has a thermoregulatory effect.

In their earlier work the team reported that: “Temperature recordings indicate that yawns and stretches occurred during increases in brain temperature, with brain temperatures being restored to baseline following the execution of each of these behaviors,” the researchers explain. “The circulatory changes that accompany yawning and stretching may explain some of the thermal similarities surrounding these events.”

Now, in a paper authored by Andrew Gallup and Omar Tonsi Eldakar, currently in press and entitled “Contagious yawning and seasonal climate variation”, the researchers explain that, “the proportion of pedestrians who yawned in response to seeing pictures of people yawning differed significantly between the two conditions (winter: 45%; summer: 24%).”

They conclude that, “The incidence of yawning in humans is associated with seasonal climate variation,” and that infectious yawns are affected by factors other than the individual’s social characteristics or brain power.

Shoup-Knox ML, Gallup AC, Gallup GG, & McNay EC (2010). Yawning and stretching predict brain temperature changes in rats: support for the thermoregulatory hypothesis. Frontiers in evolutionary neuroscience, 2 PMID: 21031034

Gallup AC and Eldakar OT(2011) Contagious yawning and seasonal
climate variation. Front. Evol. Neurosci. 3:3. DOI: 10.3389/fnevo.2011.00003

I did a double take when I saw the most recent offer to land in my inbox: “a $20 Brazilian Blow Dry”. I quickly realised it was a hair treatment wholly unrelated to waxing or any kind of sexual activity, but my being less than cranially hirsute, I’ve not taken much interest in such matters as straightening. Apparently, this trendy Brazilian hair straightening treatment tames curls and frizz in just a couple of hours, lasts months, and is very popular with various celebs and increasingly a public hoping to emulate their idols.

However, in August, the US Food and Drug Administration (FDA) apparently sent a first warning letter to the manufacturer of a trendy hair-straightening product. The letter concerned the alleged presence of the toxic carcinogen formaldehyde at levels well above those considered safe in a consumer product and the alleged inappropriate claims by the company that their product is free of formaldehyde. Salon owners and clients allegedly exposed to the product claim to have suffered, headaches, eye irritation, nausea, dermatitis, allergic reactions, chest pain, asthma, insomnia and depression.

Chemical safety and testing of thousands of consumer products is rightly high on the agenda in many regulatory areas. Initiatives in the EU, US and elsewhere attempt to rationalize testing and approval of thousands of chemicals to improve consumer understanding of domestic and other products and to reduce the risks associated with exposure to a wide range of toxic and corrosive substances. It is frustrating therefore to learn of abuses in which products are wittingly formulated with excessive quantities of chemicals with known risks. This does nothing for the public perception of chemistry and provides the tabloids with yet more fodder with which to color their scaremongering headlines of this ilk: “Could your blow-dry poison you?”, “The hair treatment of death” and “The Brazilian that could cause cancer”. All deeply unscientific statements as expected of this section of the media.

So, what is Brazilian hair straightening and why has it become a problem. The treatment is designed to “tame curls and frizz” in just a couple of hours. Apparently, it lasts for several months, unlike non-chemical hair straightening and has become increasingly popular with image-conscious celebrities and those members of the public who seek to emulate their looks or develop their own straightened style.

Unnamed chemicals in the lotions are used make the hair receptive to added keratin, the hair protein. Adding keratin and then using conventional hot iron hair straighteners allows the stylist to remove natural curls or frizz from hair and produce the much-sought after effect. The bound keratin keeps the hair in its newly straightened state for several weeks. But what of those unnamed chemicals? Consumer pressure in 2010 and into 2011 led to investigations by Oregon Occupational Safety Health Administration (OHSA), Health Canada others revealed that one of the ingredients is formaldehyde. Formaldehyde is a colorless and pungent gas widely used in the manufacture of polymers and other products with annual production of more than 23 million tonnes. Its aqueous solution, known as formalin, has been used as disinfectant, for preserving biological specimens and as embalming fluid. It is a known human carcinogen, according to the US National Toxicology Program official announcement in June 2011. It has also been implicated in sick-building syndrome because of its widespread presence in construction products such as wood, fillers and synthetic board.

International regulations suggest that 0.2% formaldehyde solution is the upper limit on safety for consumer products. Health Canada’s analysis of a wide range of hair products revealed formaldehyde levels up to 10%, 50 times above the 0.2% threshold. Meanwhile, Oregon OHSA analyzed air samples from hair salons using the products and found those to be well above regulatory safe limits.

This latter point is supported by University of Liverpool chemistry researcher Robert Slinn. Formaldehyde, CH₂O, is a toxic and irritating gas that is very soluble in water, he says. Commercially, formalin is a saturated 40% v/v aq. solution (about 37% w/w). He points out that 1 ml of such commercial formalin contains approximately 400 milligrams of formaldehyde. A preparation containing 10% formalin solution, the worst determined by Health Canada, would thus contain about 40 mg of formaldehyde. 1 ppm in the air is the threshold for causing eye irritation in most people (anything below that and very few people would be irritated). The use of several containers of product in the enclosed space of a hair salon each week could readily lead to concentrations of formaldehyde in the air well above permitted levels, Slinn says.

The manufacturers insist that their products are safe and that they contain no harsh chemicals and are labeled as formaldehyde-free. The FDA’s tests allege that methylene glycol, the liquid form of formaldehyde, is present at levels ranging from 8.7 to 10.4%. The agency’s first warning letter asserts that companies cannot label their products as formaldehyde-free if they’re not, obviously that would be misleading.

Were the tabloid scare stories correct for once? Yes and no. They were correct insofar as products labeled “formaldehyde free” have allegedly been sold with incorrect labeling and some of those products were shown by analysis to contain formaldehyde in solution at levels higher than regulations for consumer products allow. As with any toxicity, dose and exposure routes are critical. There are presumably thousands of people using the various hair-straightening products, a class action legal case is underway, but the headline claims of Brazilian killers are probably overblown.

I’m a Scientist – The Film. Imperial College protein crystallographer Stephen Curry asks scientists to explain themselves, about how they got interested in science, what keeps them going and what makes a good scientist. Features Jenny Rohn (author of two well-received sci-lit novels), Tim Hunt, Laurence Pearl, Amar Joshi, Bernadette Byrne,

Brewing up synthetic yeast – My latest news story for Chemistry World discusses artificial life. US scientists have taken the first tentative steps towards a synthetic yeast genome. They're not planning to bake bread or brew beer with their new artificial life form but the work could expand the toolbox with which researchers can manipulate DNA. The approach might be used to introduce genetic diversity into the genome for selection experiments.

Clyde Hutchison of the J. Craig Venter I Hope Institute sent me a few words regarding the development:

“This work is another remarkable example of how synthetic biology can be used to rewrite chromosome sequences at a sizable scale. Implications of this work include the better understanding of the rules that govern genome structure and behavior in yeast, one of the most important model systems for understanding biological processes. Specifically, what makes the work particularly interesting is that when the CRE recombinase is transiently expressed in yeast cells carrying the synthetic region, extensive recombination occurs between pairs of loxP site leading to a variety of deletions and inversions of the DNA between the sites. The authors describe a number of the new phenotypes generated. This work could be extended to other segments, yielding considerable information about the genetic structure of the yeast genome. However, it seems unlikely that segments greater than a few hundred kb in length could be simultaneously analyzed without total lethality, since even with the 90kb synthetic segment the viability was reduced 100-fold on CRE induction. This is however an excellent example of the power of direct chemical DNA synthesis for genome engineering. The assembly of genome segments from synthetic pieces allows the construction of genomes that would be virtually impossible to obtain by other approaches.”

At what temperature does pure water at atmospheric pressure boil? asks James Poskett in this month’s Last Retort column in Chemistry World. The obvious answer is 100 Celsius, but the boiling point of pure water can be as low as 97 Celsius (at atmospheric pressure) and as high as 109 Celsius! And this has nothing to do with colligative properties in which adding a solute, such as salt, to water raises its boiling point and conversely lowers its freezing point.

Poskett points to an intriguing video on the University of Cambridge website that shows the thermometer creep past the 100 degrees mark as distilled water boils in a glass beaker (The yellow highlight in the picture above shows the water boiling at 100.9 Celsius). He discusses the notion of “cold” being something positive, rather than simply the absence of heat. He scoffed at the notion, at first, but it’s a concept well known to chemical engineers and plant designers who talk about “coolth” being the opposite of “warmth”…

UPDATE: Rory CL at the BBC tweeted that there has been no leak of radioactive materials.

AFP is reporting an explosion at Marcoule, located in the Chusclan and Codolet French communes, near Bagnols-sur-Cèze in the Gard department, within Côtes-du-Rhône region. Marcoule site of first industrial and military plutonium experiments. Diversification of the site was started in the 1970s with the creation of the Phénix prototype fast breeder reactor, and is today an important site for decommissioning nuclear facilities activities.

BBC reports: “One person was killed and three were injured in the explosion, following a fire in a storage site for radioactive waste.”