A lethal Christmas star

There was an ugly rumour that the giant red star, Betelgeuse, that is the right shoulder (on the left as you look at it) of the constellation Orion is “about to” go supernova. The rumours seemed to have started earlier in the year when observations suggested that Betelgeuse had changed shape, a sure sign of imminent explosion. Phil Plait apparently debunked the claims on his BadAstronomy blog.

But what difference would it make to us if the star whose name is derived from the Arabic phrase “armpit of the white-belted sheep” were to explode? Could this be the worst case of Health and safety gone mad or a serious concern? Would we need sunglasses, tinfoil hat or simply resign ourselves to meeting ELE.

A physicist friend of mine suggested that Betelgeuse at (probably, about) 640 lightyears distance from earth is close enough that it going supernova would be an extinction-level event if there were a plume of gamma rays emitted in our direction. My son and his physics teacher disagree, suggesting that it’s too far away to cause anything but a bright light in the night, and perhaps daytime, sky.

Nathan Bergey was keen to point out that whether or not we should worry about a particular supernova really would depend on the distance, the type of supernova, and the direction of emissions. Wikipedia has its own interpretation, he pointed out and suggested that a 1 or 2 thousand parsecs (3000-6000 lightyears) might be a safe distance to be once the blue touchpaper were lit on any stellar neighbour.

According to a 2004 study, a gamma ray burst [from a supernova] at a distance of about 3,262 lightyears could destroy up to half of Earth’s ozone layer; the direct UV irradiation from the burst combined with additional solar UV radiation passing through the diminished ozone layer could then have potentially significant impacts on the food chain and potentially trigger a mass extinction. The authors estimate that one such burst might be expected every billion years or so.

My physicist friend points out that we could easily measure the neutrino flux from the 1987 supernova SN1987A, which is 170,000 lightyears away. Radiation intensity goes with distance squared so the radiation field from Betelgeuse would be 1000 times as intense as 1987A, “it would be fun, but probably not fatal,” he concedes. “A supernova at 50 lightyears would probably be more of an issue.”

One of the problems with supernova risk assessment is that we’re not entirely sure what lies between us and the putative fireball. If there are clouds of hydrogen and cosmic dust, then lethal gamma rays will tend to undergo Compton scattering at lower energies and form electron/positron pairs at higher enegies so the intesity will tend to dissipate as the rays travel through space.

In the 1950s, public information movies warned you to duck and cover when you saw the flash from a nuclear bomb. That was never going to save your skin, but nor was a tinfoil hat. Next time you’re musing on a starry, starry night just remember to keep a good pair of sunglasses handy alongside your telescope.

Sciencebase person of the year 2010

Anyone can pick someone famous, a Zuckerberg, a Jobs, a Gaga, and call them their person of the year. But, how about a personal person of the year? Here’s my pick of the people who have had the biggest impact on me this year, whether through their retweet efforts on Twitter, their comments on my Facebook page, or simply by being entertaining…so in no particular order:

Justin Reid – for the most entertaining, comical and intriguing posts.

Aboud Jumbe – for international and environmental scientific insights.

Ed Yong – the most aspirational and inspirational science blogger I know.

Stu Clark – for his writing, his prog rock credentials, and his twin-neck guitar.

Crispian Jago – Witty uber skeptic.

Jo Brodie – for twitter efforts, feedback and words.

Amit Agarwal – tech blogger extraordinaire, always seems to be ahead of the tips.

Jon Edwards – chemical press officer, always willing to help, critique and shred.

Martyn Poliakoff – for the hair, for the supercritical fluids and for the periodic videos.

NHS Choices Editorial Team – NHS Choices News staff expertly tear into tabloid medical stories in a much healthier and informative way than a certain Bad column.

And, if I had to pick one of those people for being the most informative, entertaining and amusing…am I here to amuse you? It would have to be Crispian. His latest side swipe at “the” anti-atheist troll that shall not be named is just hilarious, especially as said troll now frequents my Facebook fan page for some unknown reason.

A few facts about asbestos

Today, medical journal The Lancet has publicly criticised the Canadian government for its attitude towards asbestos, saying that although Canada will not expose its own citizens to asbestos, it will continue exporting the deadly substance to developing nations [Canada accused of hypocrisy, Lancet].

A few facts about asbestos

  • All forms of asbestos are proven human carcinogens
  • No exposure to asbestos is without risk
  • All forms of asbestos cause the debilitating lung disease asbestosis
  • All forms of asbestos can cause malignant mesothelioma
  • All forms of asbestos can cause lung cancer
  • All forms of asbestos can cause laryngeal cancer
  • All forms of asbestos can cause ovarian cancer
  • All forms of asbestos can cause gastrointestinal cancer
  • All forms of…you get the picture
  • Asbestos is still widely used
  • Just 52 countries have so far banned asbestos outright

According to scientists at the Collegium Ramazzini in Modena, Italy, “a large number of countries still use, import and export asbestos and asbestos-containing products.” More to the point, despite the above facts, many countries that have banned other forms of asbestos, still allow the so-called “controlled use” of chrysotile asbestos, which is exempted from the ban for political and economic reasons (lobbying by the asbestos mining and manufacturing industry, in other words). The exemption of white asbestos from a ban has no basis in medical science. The microscopic nature of asbestos fibres means that they can get deep into the lung when breathed in where they stay triggering problems.

asbestosAs such, the Collegium, and many other organisations [Environ Health Perspect. 2010, 118, 897-901] are pressing for a full, international ban with no exemptions, “To protect the health of all people in the world – industrial workers, construction workers, women and children, now and in future generations”. A total ban rigorously enforced is urgently needed.

Asbestos is not a single substance but any of six naturally occurring fibrous minerals. These minerals exist as either serpentine or amphibole forms. The only serpentine asbestos is chrysotile, commonly known as white asbestos, which accounts for 95% of all asbestos used around the world, it is the only form still being used. The amphibole minerals: amosite (brown asbestos), crocidolite (blue asbestos), tremolite, anthophyllite and actinolite, are no longer used. Asbestos was once hailed a wonder material for the construction industry because it can withstand fire, heat and acid, has great tensile strength and acts as both an effective thermal insulator and sound-proofing material. Unfortunately, its wonder comes at a price to health.

Still today at least 125 million people around the world are exposed to asbestos through their work [Egilman et al., Am J Ind Med. 2003, 44, 540-557] and many millions more were exposed throughout their working lives, with about 20 to 40% of adult men reporting past occupations that may have involves exposure to asbestos. In addition to mesothelioma, 5 to 7% of all lung cancers are thought to be due to occupational exposure to asbestos. [Tossavainen, Int J Occup Environ Health., 2004, 10, 22-25]. Those who feel that they have been affected by asbestos exposure can visit the mesothelioma news site for information regarding your rights.

The Collegium concludes that the risks associated with exposure to asbestos cannot be controlled by technology nor by regulation of working practices. Scientists and responsible authorities in countries allowing the use of asbestos should be under no illusion that controlled use of chrysotile asbestos is an effective alternative to a ban on all use of asbestos. They point out that safer alternatives are now widely available and widely used in countries in which a ban is enforced, there is no excuse for not banning asbestos outright.

Research Blogging IconCollegium Ramazzini (2010). Asbestos is still with us: repeat call for a universal ban International Journal of Environment and Health, 4 (4), 380-388

What is nature worth?

Each hour 3 species vanish forever, we’ve lost a fifth of the planet’s coral reefs, almost a third of its mangrove forests, and half of the world’s wetlands. But, how do you count the cost? Perhaps a business perspective is needed. If we considered the natural world as providing products and services maybe, we’d feel less easy about devaluing biodiversity and the environment.

Nature Capital Project is taking this ethos to its logical conclusion by aligning economic forces and conservation.

Searching for scientific abbreviations

Ambiguous abbreviations and acronyms are annoyances when it comes to text search and data mining. As a writer-editor, I was always taught to spell out the long form (LF) of a short form (SF) at first mention in a document so that the reader would know that when I mentioned EBV I was referring to Epstein-Barr virus rather than estimated blood volume. Hopefully, I do that on Sciencebase so that no one is confused, but not all authors give the LF for their SF, especially if they are writing in a niche where the readership is unlikely to be confused by an abbreviation.

Short forms of lengthy technical and jargon phrases are commonly made using one of a handful of general rules: cutting off the end of a gives us admin for administration or administrator, first letter initialisation, makes an abdominal aortic aneurysm AAA. In chemical names it is quite useful to abbreviate using the initials of the word’s syllables, so benzodiazepine becomes BZD, there are also combination initialisations, ad libitum to ad lib and other substitutions so that primum atrial septal defect becomes ASD I. In the field of science the list is almost endless and the potential for overlap a sub-editor’s nightmare.

If an author were to mention AAA, would a reader outside that niche know they were referring to the American Automobile Association, US punk band Against All Authority, a type of electrical battery, the major professional association for anthropologists in America, an abdominal aortic aneurysm or any of dozens of other LFs for the SF AAA? More commonly, authors do give some form of LF for their SFs. They either spell out the phrase in parentheses or use a phrase like “stands for” after the short form is first mentioned, but not always. How can a data miner cope?

Informatics researcher Min Song of the New Jersey Institute of Technology, in Newark, and Hongfang Liu of the Department of Biostatistics, Bioinformatics, and Biomathematics, at Georgetown University, Washington DC, have come up with a new way to analyse a document and to extract appropriate chunks of words that can deduce the long forms and their corresponding short forms in biomedical text. In general, Song and Liu’s work focuses on the discovery of knowledge in large volumes of natural language data such as blogs, medical notes and scientific publications. One aspect of this is the LF-SF conundrum.

Other researchers have tried to extract the SFs and the LFs from text with varying degrees of success in the past. Accuracy has been relatively high for extraction within specific niches so that algorithms are available that can recognise SFs like 1H-NMR and determine that it means proton nuclear magnetic resonance spectroscopy. But, the measure of success in this earlier work may be subject to the closed nature of the studies. The researchers says that his approach differs in that it could be more generally applicable because it incorporates lexical analysis techniques into supervised learning for extracting abbreviations.

Song and Liu add that his proposed technique, known as LFXtractor, uses noun chunking together with a distance metric to detect SF- LF pairs regardless of the presence of parenthetical expressions. “The distance-based matching method proposed is more scalable compared with traditional pattern-matching methods,” he says. “Given a sentence, the text chunker detects grammatical phrases including noun phrases in the sentence and the (SF, LF) pair detector identifies the corresponding LF for an SF given a list of LF candidates by computing a distance between the SF and its LF candidates.”

Song and Liu has trained and tested LFXtractor using PubMed queries and developed a web-based interface. He has carried comparisons with other tools, ExtractAbbrev, a simple pattern-matching rule-based system, ALICE, a heuristic rule-based system, Acrophile and collocation. LFXtractor scored higher than all the other approaches on precision, recall and F-measure (a calculated single-value combination of the former two). F-measure values for the various approaches were as follows: ExtractAbbrev (0.59), ALICE (0.62), Acrophile (0.54), collocation (0.63) and LFXtractor (0.68).

In follow-up work, the team will develop an abbreviation server that connects to the PubMed system and retrieves MEDLINE records from which abbreviations are then extracted and analysed using LFXtractor.

Research Blogging IconMin Song and Hongfang Lui (2010). LFXtractor: Text chunking for long form detection from biomedical text International Journal of Functional Informatics and Personalised Medicine, 3 (2), 89-102

Santa Claus Science

Santa Claus, Father Christmas, Saint Nicolas, Kris Kringle, Sinterklaas. Call him what you will, at this time of year, for children who celebrate everywhere, many questions of a scientific nature arise and parents squirm in their efforts to answer them.

Now, Gregory Mone, a contributing editor at Popular Science, tells us to forget all about the fat, jolly bloke dressed in red, the elves, Mrs Claus and an Arctic home. Apparently, Santa is actually from Greenpoint, Brooklyn, and he’s not nearly as fat as he used to be. More to the point though, technology has caught up with the old guy and eavesdropping ornament implants, cloning and wormholes are all now at Santa’s disposal on Christmas Eve.

This affectionate book published for the first time today in the UK, billed as hilarious and fantastically illustrated is the perfect 2010 complement to Roger Highfield’s 2002 book Can Reindeer Fly?: The Science of Christmas. Put The Truth About Santa on your amazon wishlist and just hope that Santa’s checking online in plenty of time for Christmas.

Cancer, Gulliver, cat and mouse

Forget fruit and veg. Lose weight and cut the booze to reduce cancer risk
People should be warned that cancer is linked to obesity and alcohol, rather than urged to eat more fruit and vegetables to protect against the disease.

UK trialling testing sugar-coated salt on roads
Although they’ve been using molasses for years in Nebraska and other places to help salt stick to the roads, it’s only just occurred to us Brits to give it a try now that we’re entering a period of severe cold weather (again). Add salt to water and it lowers its freezing point so that it has to be that bit colder for the roads to stay frozen. However, salt kicks up too easily, add molasses and the salt gets more of a purchase on the icy roads and helps defrost them (ever so slightly) producing a nice brown slush.

Stuart Little does a Benjamin Button
Researchers have identified targets (related to the enzyme telomerase) that could help produce old-age-defying drugs and a fountain of youth for the baby boomer population… but haven’t we heard this all before? Of course, we have. It’s unlikely ever to come to anything more than next-generation Botox.

Gulliver Turtle is looking for candidates for BioMed Central’s 5th Annual Research Awards
BioMed Central’s Research Awards are now in their fifth year and apparently growing in popularity. The awards were set up to recognize excellence in research that has been made universally accessible by open access publication, so get your nominations in and see if Gulliver picks you.

Cat and mouse
No sooner do the US authorities begin stealing web domains illegally (actually just taking out the domain from DNS servers), than users find a way to fight back using a DNS system that cannot be touched by any governmental institution and works a P2P network. The problem being that an innocent party might have their domain blocked by the US before due process has taken place and on spurious grounds (and all this before the legislation even comes into effect).