David Bradley – Page 306

Scratchy and itchy

Researchers are only just begin to scratch the surface of the brain with functional MRI. Now, a study of perception in both allergen- and histamine-induced itch has revealed how different parts of the brain are activated in response to stimulation from each type.

Allergens, such as pollen and dust, and histamine released by allergy cells as a result of activation by foods, drugs, or infection often lead to a vicious itch?scratch cycle as any allergy sufferer will tell you. However, researchers at Oxford University have demonstrated that the brain responds differently to itchiness caused by allergens and histamine.

Siri Leknes, Susanna Bantick, Richard Wise, and Irene Tracey at Oxford have worked with Carolyn Willis and John Wilkinson of the Department of Dermatology, at Amersham Hospital to try to understand the nature of itch? cycle with a view to improving outcomes for allergy sufferers and people with certain chronic skin conditions.

Read on in the latest science news round-up from David Bradley on spectroscopynow.com

Being particular about DNA

Surface-enhanced Raman spectra (SERS) of DNA and RNA mononucleotides can be detected with high sensitivity, according to UK researchers. Using citrate-reduced silver colloidal nanoparticles aggregated with magnesium sulfate instead of the more common halide ions, reduces inappropriate enhancements and produces spectra that are sufficiently different to allow each to be distinguished.

“The main advantage of our SERS approach is that it allows direct label-free identification of mononucleotides in aqueous solution,” Steven Bell, Director of the Innovative Molecular Materials Group, at Queen’s University Belfast, explains, “There is no requirement for labels because the Raman signals of each of the mononucleotides are intrinsically different due to the differences in their chemical structures.” He adds that spectra can be obtained at ten nanograms per millilitre. “We were working with large samples but reducing the sampling volume to a few microlitres would move the sample down to tens of picograms,” he says.

More…

Nervous scoop

An action shot of the protein Scp1, which plays a crucial role in the development of the nervous system has been obtained using crystallography by researchers in the US. Their structure could provide drug designers with a template for creating small molecule inhibitors of this protein that would be useful in neurological research.

Joseph Noel and Samuel Pfaff of the Salk Institute for Biological Studies and colleagues there and at the University of California, San Diego (UCSD) and The Scripps Research Institute, La Jolla explain that a network of signalling molecules controls embryonic stem cell differentiation. Controlling the controllers might allow scientists to nudge embryonic stem cells into becoming specific cell types, which would be useful in basic research and for potential therapies.

Read on…

PLoS ONE Impact Factor

UPDATE: June 21, 2010: At last, PLoS ONE has now been given an impact factor of 4.351, which puts it into the 25th percentile of the “Biology” category.

UPDATE: June 19, 2009: ISI will publish its latest stash of impact factors on the evening of the 19th. We will hopefully find out then whether or not a PLoS ONE impact factor will be made public, and just how well it is rating relative to the traditional journals.

Until recently, online scientific journals were really just e-versions of the printed copy. Of course, we had advance publication online and ToC alerts etc, but now Public Library of Science will publish a general science journal to rival Science and Nature that covers primary research results from all areas of science. Unique to the new format is the use of both pre- and post-publication peer review, which are set to revolutionize the way the scientific literature evolves.

PLoS co-founder Harold Varmus says, ‘For those of us who have been engaged with PLoS from its conception, the launch of PLoS ONE is tremendously exciting–this is the moment when we seize the full potential of the Internet to make communication of research findings an interactive and fully accessible process that gives greater value to what we do as scientists.’

It has launched with publication of 100 peer-reviewed research articles peer-reviewed under the guidance of an extensive academic editorial board, and covering molecular science and clinical studies with topics including the evolution of language, the control of rabies, mimicry of jumping spiders, and Alzheimer’s disease.

Every article published is under an open access license, which means everyone is free to read, reuse, and build upon these research papers.

One of the key selling points is the possibility of almost instantaneous publication with virtually zero delay between submission and publication. As soon as a paper is published a dialog between author and reader is opened.

PLoS launched in “beta” in December, 2007 could see big changes in the way the scientific literature evolves.

UPDATE: 2009-06-16 Recent headlines added:

Open Access Publisher Under Scrutiny for Taking Sham Paper
Science publishing also suffers from its curmudgeons
What’s wrong with scholarly publishing today?
Merck’s Ghostwriters, Haunted Papers and Fake Elsevier Journals
Scholarly community gives feedback regarding Wikipedia
Scitable is a Social Network for Science
The Impact Factor Game
Scitable is a Social Network for Science
Guestimating PLoS ONE impact factor

Top Physics Discoveries of 2006

Sharpest manmade thing Over at the American Institute of Physics my colleague Phillip Schewe and his team have been putting together their pick of the physics discoveries for 2006.

Their number one choice had to be the new ultra precise measurement (0.76 parts per trillion uncertainty) by Gerald Gabrielse and his colleagues at Harvard University of the electron’s magnetic moment closely followed by the refinement by the same team of the fine structure constant that reveals that the electromagnetic force allowing atoms to hold on to their electrons is lower than previously thought.

Other top physics discoveries included new evidence that dark energy, the hypothetical mechanism for the accelerating expansion of the universe, was present even in the early universe; elemental discoveries of 118 and 116.

Next on the list are

The world’s sharpest object
The best direct test of Einstein’s (in)famous E=mc² formula
The first direct measurement of turbulence in space
A new measurement of the cosmic microwave background radiation
The first study of matter-antimatter chemistry
Advances in “two-dimensional light”, plasmonics
Advances in “two-dimensional carbon”, graphene
Gravityy wave model
2006 Nobel prize in Physics for George Smoot and John Mather

More details on the PNU site here.

Analytical techniques clean up diesel

Raman spectroscopy, X-ray diffraction, and electron microscopy could help diesel engine components manufacturers meet tough new emissions regulations, according to researchers at Oak Ridge National Laboratory’s High Temperature Materials Laboratory (HTML).

The techniques can provide detailed characterizations of materials and allow components to be tested for heat and stress effects more effectively as part of the industry’s preparation for new emissions mandates that come into effect in the US in 2007. Under the new laws, a 90% reduction of nitrogen oxide, NOx, and particulates from diesel vehicles will be required.

“Environmental Protection Agency regulations are pushing emissions control technology very hard,” explains Arvid Pasto, director of the HTML, “so that engine and emissions control equipment manufacturers require access to very sophisticated tools to develop this technology. Fortunately, our user facilities are well equipped to help them.”

Diesel engine-maker Cummins, for instance, has used HTML’s analytical capabilities to better understand the properties of materials used in exhaust after-treatment systems. In addition to studying how catalysts can be adversely affected by sulfur and other gaseous exhaust components, Cummins and HTML have worked together to characterize the fatigue life of cordierite diesel soot filters, which remove more than 98% of particulate emissions from diesel exhaust. These exhaust after-treatment devices are critical to meeting upcoming emissions requirements.

Another company Industrial Ceramic Solutions, of Knoxville, Tennessee, used HTML’s scanning electron microscope facility to analyse material being developed for ceramic-fibre diesel particulate exhaust filters. The original material did not function as well as competing products and had a tendency to crack. The tests revealed that the fabrication process was to blame and ICS has modified its process to improve the product.

‘The sophisticated electron microscopy at HTML allowed our small business to literally look inside of the ceramic fiber filter media at thousands of times magnification,’ said Richard Nixdorf, ICS president and CEO. ‘This information led ICS to solutions that eliminated micro-cracking and moved our filter-media strength far beyond what the diesel exhaust filter application demanded.

Chemistry News

More chemical news from the current issue of Reactive Reports, now online.

Bedwetting Chemistry – A higher concentration of sodium and urea in urine could underlie a type of bedwetting in children that does not respond to the common medication, desmopressin.

Rubber Suits You Sir – Military personnel, chemical workers, and others could benefit from a new synthetic rubber material tailored with liquid crystals.

Biomolecules Out on a Wing – Photonic crystals give butterflies their beautiful colors and synthetic versions are now being developed for a range of technological applications.

Salt and the Boiling Point of Water

TL:DR – If you dissolve salt in water, you raise its boiling point. Similarly, you also lower its freezing point. These effects occur with any solute dissolved in any solvent and depend on how many solute particles are dissolved in the solvent. The key phrase is colligative properties.

Colligative properties include: Relative lowering of vapour pressure (Raoult’s law), elevation of boiling point, freezing point depression, osmotic pressure.

Colligative properties determine how a solvent will behave once a solute is added to make a solution. The degree of change depends on the amount of solute dissolved in the bulk liquid, not the type of solute. So, without my doing your homework for you…how does adding salt to water affect its boiling point? You will find several clues and several keywords above and below.

The fact that dissolving a salt in a liquid, such as water, affects its boiling point comes under the general heading of colligative properties in chemistry. In fact, it’s a generic phenomenon dissolve one substance (the solute) in another (the solvent) and you will raise its boiling point.

So, here’s a rough explanation of what’s going on. If a substance has a lower vapour pressure than the liquid (it’s relatively non-volatile in other words) then dissolving that substance in the liquid, common salt (NaCl) in water (H₂O), for instance, will lower the overall vapour pressure of the resulting solution compared with the pure liquid. A lower vapour pressure means that the solution has to be heated more than the pure liquid to make its molecules vaporise. It is an effect of the dilution of the solvent in the presence of a solute. If you want to know about tungsten and why it is used in incandescent light bulbs please check out the Wikipedia entry.

Put another way, if a solute is dissolved in a solvent, then the number of solvent molecules at the surface of the solution is less than for pure solvent. The surface molecules can thus be considered “diluted” by the less volatile particles of solute. The rate of exchange between solvent in the solution and in the air above the solution is lower (vapour pressure of the solvent is reduced). A lower vapour pressure means that a higher temperature is necessary to boil the water in the solution, hence boiling-point elevation.

Conversely, adding common salt to water will lower its freezing point. This effect is exploited in cold weather when adding grit (rock salt) to the roads. The salt dissolves in the water condensing on the road surface and lowers its freezing point so that the temperature has to fall that bit more before ice will form on the roads.

A much more fun use for freezing point depression is to add salt to ice to make ice cream. The About site has some instructions on how to do this, although it’s probably not too tasty.

Curiously, at least one Sciencebase reader was searching for the phrase “how does sugar affect the boiling point of water?” and landed on this page. This is essentially the same question as, “does salt affect the boiling point of water?” The nature of the solute, the material being dissolved in the solvent, is pretty much irrelevant at a first estimate. Rather, it is the amount of material that is dissolved (which depends on the materials solubility) that influences the boiling and freezing points as described above.

Boxing Day Boredom and Monkey Proteins

Monkey proteins It’s Boxing Day and you’re probably seriously bored playing the “normal” game of Pick-up Monkeys. Rather than heading for the Wii or the PS3, how about adding a little monkey magic, or more seriously some wire binders and following Dr N. Michael Green, Division of Mathematical Biology, of the UK’s prestigious Medical Research Council (MRC) National Institute for Medical Research to do a little bit of science education with those colourful plastic monkeys.

“Pick up Monkeys’ was originally produced as a children’s game (1965) and they have proved very versatile,” Green explains, “I discovered in 1968 that they were ideal models for protein subunits, being asymmetric, having multiple interaction sites and available in several colours. This exhibition illustrates their use in modelling the geometry of multi—subunit protein structures.”

Stop monkeying around, take a look at Green’s site to get the hang [pun intended!] of proteins. It’s a great idea for a science fair project too.

Booyle rocket

UPDATE: They were so obviously (I know hindsight is 20:20) looking for information about the Wes Anderson movie “Bottle Rocket” and simply mistyped…

Bottle rocket What on earth’s a “booyle rocket”, I hear you ask! Well, I haven’t a clue. It’s just a search term that a Sciencebase visitor used in our search box.

Intrigued, I Googled the phrase and it turns out to be a Google Whack Blatt to a rather crude dating site. Fortunately, Google also offered the option that perhaps I’d misspelled bottle…so was the visitor searching for “bottle rocket”, perhaps?

If they were then there is a stack of information on that term. 1,590,000 pages in fact in my search including reference to a 1994 (or 1996, two IMDB entries, same movie, different years) Wes Anderson movie of the same name. But, I think visitors to this site are more likely to have been looking for a science project kind of bottle rocket rather than a movie.

Unfortunately, we don’t have a bottle rocket science project to offer but this site does and it looks so quick and simple that I thought it worth mentioning.

So, if you’re totally bored with all the goodies you received yesterday already, then check it out, grab some scissors and a fizzy drinks bottle, and head out to the local recreation ground to show off your favourite “new” toy.

Open access news