David Bradley – Page 344

Nugache P2P Bot

Just as email worms are at their lowest ebb for years, a new threat looms on the horizon – the P2P (peer-to-peer) bot. These insidious creatures worm their way through instant messanging systems (naming no names, but anyone using MSN and AOL products might just be at risk).

Rather than doing the usual email address look-up that is common to most mail worms, this form of malware, of which Nugache is the current threat being popularised by the media, bypasses address books and even circumvents DNS lookup (the tool that converts net addresses into a numeric IP address) and instead scans for other infected machines with which to hook up and create a P2P network. These are not to be confused with the networks that P2P file sharing software uses. Once established, encrypted packets of information can be transferred across the bot network all-but invisible to the usual detection systems.

It looks like most of the antivirus companies have responded with appropriate updates (is it the companies themselves that write these darned things, by the way?) and I’d recommend you do an update immediately, even if it’s not convenient to ensure you’re safe from Nugache at the least.

For those with an interest in the ins and outs of this particular worm, it opens a back door on TCP port 8, and installs a bot to wait for commands from the attacker. The command and control channel it uses is unique and it is difficult to block commands issued to the bot. Anyone looking for the perpetrator would simply see the various peers in the bot network making tracking them down almost impossible.

Benzene Soft Drinks Redux

One further thought on the benzene soft drinks story following on from sciencebase reader Ross Getman’s comment…

Bob Buntrock (of Louisiana State University) on the CHMINF-L discussion group mentions the recent C+EN article on this issue, (Dispute Over Benzene In Drinks, Bette Hileman, Chemical and Engineering News, 84(17), April 24, 2006).

Buntrock points out that when tests were carried out again in 2005, they revealed a very different picture of benzene levels than before. Apparently, previous tests by the FDA showed that almost four out of five beverages tested, even after “reformulation”, had benzene levels greater than 5 ppb, the US standard for tap water. The latest (preliminary) tests showed no benzene or levels less than 5 ppb.

“Since the first method involved heating samples at 100 Celsius for 30 minutes(!) [His exclamation] and the latest method uses headspace methodology “which does not involve much heat”, guess which method would appear to be more accurate,” says Buntrock. In his opinion, “considerably more decarboxylation of many acids or carboxylates will occur under the previous drastic conditions, which are extremely unlikely to occur under normal usage of soft drinks.”

Jacob Zabicky of Ben Gurion University, Israel, followed up Buntrock’s comment with a remark based on knowledge of the physical properties of benzene. “My gut feeling based on the relative solubility of benzene in water and its volatility from solution at ppb levels,” he said, “is that if there is any ppb level benzene at the start it will go with the fizz.” On the basis of the Henry Constant of benzene in water, Zabicky adds that, “The given value means that for every four molecules dissolved in a given volume of water one molecule of benzene is found in the same volume of headspace in equilibrium.” In other words if the headspace volume is large (i.e. the air above a drinks can as it is opened) compared to the volume of soft drink, then the benzene will be strongly depleted from it.

Disease Mongering

I was a bit tardy covering the recent conference on disease mongering, but to make up for it have posted a new poll on the SciScoop site to give visitors a chance to voice their opinion.

A conference held April 11-13, in Newcastle, Australia, raised some serious questions about the motives of the pharmaceutical industry. The patents on drugs for old-fashioned diseases that were originally making a $1billion a year are almost all expired and new avenues of research under the umbrella of biotech have yet to make the same level of return for other diseases. As such, there is a feeling among some observers that “new” conditions, such as restless legs syndrome, attention deficit hyperactivity disorder (ADHD), and sexual dysfunction are being hyped by the industry as the serious ills of our time that need new (lucrative) treatments. Is this the case or can we simply not do without the chemical fix of those repeat prescriptions? A collection of freely accessible essays on the subject of disease mongering is available on the PLOS Medicine site.

Visit SciScoop to vote in the poll and help us answer the question – “Are we drug company puppets?”

Bremelanotide MSDS

Readers interested in sexual chemistry will have spotted the recent item on bremelanotide (Sex Gets Up Women’s Noses, April 24, 2006), which is soon to enter Phase III clinical trials for female sexual dysfunction (see also PLoS Medicine on the subject of disease mongering).

Anyway, recent sciencebase visitors have been trying to locate the material data safety sheet (MSDS) for this compound (judging from the recent spate of searches on the site for that term). Anyway, ChemSpy.com has excellent access to several MSDS sources here. If it’s listed anywhere you should be able to find the bremelanotide MSDS there.

A blogger on another site discussing my short bremelanotide article, suggested that the fact this drug is odourless and colourless represented a serious risk in terms of men spiking a woman’s drink, but I wonder…this drug doesn’t knock you out or give you amnesia it just makes you horny, so if Mr B. Nomates can’t score under normal circumstances when any number of potential mates may be horny or not, it won’t seriously boost his chances will it?

Da Vinci de Leonardo

A letter in Physics Today this month discusses the archetypal renaissance man and his impact or otherwise on science, engineering and art…

Who is he?

According to the letter head, some fella by the name of Da Vinci. Perhaps he’s the same guy to whom Dan Brown is referring in his eponymous code book. I assume so. Either way, surely they don’t mean the Italian polymath born in Vinci in 1452 known to his mum as L’il Leonardo. I bet they do you know…

Periodic Table History

UPDATE: June 2011 – debate is raging as to what format the Periodic Table should ultimately take and indeed whether there is an ultimate, fundamental structure or whether it is merely a convenience. Check out the periodic table debate here.

Here’s a book no chemist, or indeed no scientist, should miss – The Periodic Table: Its Story and Its Significance, by UCLA chemical philosopher Eric Scerri. Older readers will recall my Alchemist interview with Eric Scerri.

The book has already had some excellent advance reviews, one in particular from my good friend John Emsley, of Cambridge U says: “Written to a high standard of scholarship, ‘The Periodic Table’ is the only book of its kind currently on the market, giving both an historical and philosophical perspective to the development of this key to the elements. The philosophical discussion Scerri weaves through its pages is rarely found in chemistry books, giving it a special quality that will appeal to the scientific community at large. In years to come it will be seen as essential reading for all who aspire to lecture and write on the subject.”

Peter Atkins, who I have never met admittedly, had this to say: “Few concepts are more important in chemistry than the periodic table, and Eric Scerri’s book offers a wonderfully thorough, lucid, and provocative introduction for both chemists and the scientifically literate to this major cultural contribution. Anyone interested in the foundations of chemistry will take delight, inspiration, and information from this highly approachable book.”

You can place an advance order via amazon, the book hits the shelves September 15 at $35 hardcover.

The Periodic Table

Turning Sperm Heads

Size really does matter! In fact a micro device that can analyse even the smallest of the small could help solve one of “man’s” greatest mysteries – what turns a sperm’s head and sends it in the direction of the egg for that fertilizatory encounter?

Sperm are well-known for turning their microscopic heads and changing direction (at least to those with a microscope who like to view such tiny events). Previous research (about which I wrote in 1991 under the heading “Not every sperm is sacred”) revealed that sperm turn in response to chemical signals, a process termed chemotaxis, and even have their own olfactory receptors. Such chemical messages may play key roles in the fertilization process. Defects in sperm chemotaxis may be a cause of infertility, and sperm chemotaxis could potentially be used as a diagnostic tool to determine sperm quality to treat male infertility.

However, Milos Novotny and Stephen Jacobson of Indiana University have developed a new tool to probe exactly how sperm chemotaxis occurs. In the current issue of Anal Chem, they describe the initial tests on their microfluidic device for studying sperm chemotaxis: “An advantage of the microfluidic platform over conventional chemotaxis assays is the ability to create chemical gradients with temporal and spatial stability, leading to greater repeatability in the experimental conditions.”

They add that microfluidic devices provide a convenient, disposable platform for conducting chemotaxis assays.

http://dx.doi.org/10.1021/ac052087i

Two-faced Electronic Paper

Two-faced microscopic beads that rotate through a half turn when an electric field is applied to them could be the key to creating electronic paper, according to Japanese scientists. Takasi Nisisako and his team in the Department of Precision Engineering at the University of Tokyo have developed a new technique that allows them to produce these “Janus” particles much more efficiently and with uniform size.

Other researchers have previously developed two-colored beads of between 30 and 150 micrometers diameter (a micrometer is a thousandth of a millimeter) for experimental electronic paper applications. A thin film of these particles is sandwiched between a control grid and a protective surface. Applying a voltage to specific regions of the layer through the control grid can make clusters of individual particles flip over so that they appear black against a background of un-flipped white particles. Such technology could allow a device to display an image, words or pattern that is retained using no additional power until an erase voltage is applied making the particles flip back to white.

Such electronic paper has not yet entered the mainstream electronic gadgetry market because making the particles all the same size and of consistent quality is difficult. Prototype devices based on these Janus particles cannot yet produce a perfect picture. Nisisako and his team have now solved the quality control problem by side-stepping the standard manufacturing approach and have instead turned to microfluidic technology.

The team built a tiny device that comprises a sliver of glass into which is etched a Y-shaped channel. The researchers then seal this beneath a second layer of glass leaving the ends of the channel open. The two starting ingredients are liquid monomers designed to produce particles that respond to an electric current and have a different color on each of their two faces. The team feeds each ingredient into the arms of the “Y” where the materials form a two-color stream at the junction, which travels down the leg of the “Y”. The emerging fluid droplets are all identical and are then “cured” to form solid microscopic particles.

By integrating any number of these microfluidic devices, Nisisako suggests it should be possible to scale-up the manufacture of Janus particles for commercial applications. He adds that their approach is not limited to polymer ingredients and making microparticles from other starting materials such as ceramics or metals should also be possible.

Advanced Materials

Science News with a Spectral Twist

Channelling toxins Novel treatments for high blood pressure and other disorders could emerge from high-resolution solid-state NMR studies that reveal how toxins affect the structure of potasssium channels in the cell.

Marc Baldus of the Max Planck Institute for Biophysical Chemistry in GÃ¶ttingen and colleagues in France and Germany have exploited a special protein synthesis procedure to follow how potassium channels and toxins combine to change the structure of the channel.

Zeolites step-by-step The evolution of zeolites has been followed by University of Minnesota chemical engineer Michael Tsapatsis and colleagues using microscopy and X-ray diffraction. Their study could lead to a new approach to designing and synthesizing novel variations on the zeolite theme for use as molecular sieves, catalysts, and sensors.

Analytical raft floats organic NLOs A combination of analytical techniques has proved its worth in assessing a series of non-linear optical materials for use in future organic optoelectronics devices. Juan LÃ³pez Navarrete of the University of Malaga, Spain, and colleagues at the University of Zaragoza-CSIC and the University of Minnesota, Morris, USA, used UV-vis, IR, and Raman spectroscopy, nonlinear optical (NLO) measurements, X-ray diffraction, and cyclic voltammetry to assess the properties of a series of tricyanovinyl (TCV)-substituted oligothiophenes.

A particularly golden study US researchers have devised what they describe as a very efficient method for making well-defined gold nanoparticles with equal numbers of hydrophobic and hydrophilic arms. The V-shaped arms are alternately distributed across the surface of 2 nanometre gold core particles. The solubility of these nanoparticles in a wide range of solvents means that they should be amenable to further processing with various chemical modifiers. Such nanoparticles have potential in optoelectronics, catalysis, and biomedical applications.

Cool Science Experiments

Sciencebase hosts a collection of science experiments from a cool coffee experiment to how to build a homemade electric motor.

Here is a brief list of possible science experiments, although Sciencebase no longer provides these particular write-ups you can download similar science projects via the links.

Black Light Experiment
Sinking and Floating Experiment
Oil and water experiment
Cartesian Diver Experiment
Why is the sky blue experiment
Clean up tarnished silver
Floating Soap Bubbles Experiment
Bending Water Experiment