site map
C O L O U R K E 'Y

news and comment
news lite

  brain-‘fingerprinting’ proposed for israeli airport security

Metal and similar detectors cannot detect a person trained to use their body as a weapon. An Israeli firm looks to detect a person’s intentions instead.

“Security experts say focus is shifting from analyzing the content of carry-ons to analyzing the content of passengers' intentions and emotions.”
—
“One firm, WeCU (pronounced "We See You") Technologies, employs a combination of infra-red technology, remote sensors and imagers, and flashing of subliminal images, such as a photo of Osama bin Laden. Developers say the combination of these technologies can detect a person's reaction to certain stimuli by reading body temperature, heart rate and respiration, signals a terrorist unwittingly emits before he plans to commit an attack.”
—
“… a passenger may pass through a security screening without realizing it. For example, passengers could use an automated check-in system or gaze at a screen with departures information without realizing they've just been exposed to the words "Islamic jihad" written in Arabic.

“These stimuli, explains Givon, will intrinsically elicit some sort of biometric response -- whether the passenger knows it or not -- that can be picked up by WeCU's strategically placed sensors.” [Quoted from cnn.com]

“Dr. Prabir Bhattacharya, in collaboration with Abu Sayeed Sohail, a graduate student from the University of Concordia in Montreal, Canada, has managed to develop a piece of computer software that is able to determine a person's mood just by analyzing a scanned picture of their face. The system doesn't even require the whole face to be present in the photograph, since it can detect and classify a number of facial expressions by focusing on just 15 key points on a person's physiognomy.“ [Quoted from softpedia.com]

related material
‘lie detection’

advertising
disclaimer

advertising
disclaimer

advertising
disclaimer

is it a ghost? new particle seen

“Last week, physicists announced that the Tevatron particle accelerator at Fermilab in Batavia, Illinois, has produced particles that they are unable to explain…”

related material
mad scientists - essential work going on at cern

the web address for the article above is
https://www.abelard.org/news/lite0808.php#muons_tevatron_041108

on the primitivity of disease genes

“Several thousand genes in the human genome have been linked to a heritable genetic disease. The majority of these appear to be non-essential genes (i.e. are not embryonically lethal when inactivated) and one could therefore speculate that they are late additions in the evolutionary lineage towards humans. Contrary to this expectation, we find that they are in fact significantly over represented among the genes that have emerged during the early evolution of the metazoa. Using a phylostratigraphic approach, we have studied the evolutionary emergence of such genes at 19 phylogenetic levels. The majority of disease genes was already present in the eukaryotic ancestor and the second largest number has arisen around the time of evolution of multicellularity. Conversely, genes specific to the mammalian lineage are highly underrepresented...
—
“Our data show that disease associated genes are not simply a random subset of all genes in the human genome. There is a clear bias towards old genes among them and the more recently evolved genes are seldomly disease associated. On the other hand, disease associated genes appear to be a typical subset of all types of older genes, i.e. their overall functional spectrum is not different from the whole set, as judged from the GO-term analysis. This makes it even more surprising that newly evolved genes are rarely found among them.
—
“Our findings have some general evolutionary implications. Although interaction network and transcriptional analyses suggest that disease genes are not concentrated in hubs (Goh et al. 2007; Feldman et al. 2008), their ancient origin suggests that they are nonetheless involved in old biological processes. In fact, it has been shown that disease causing mutations tend to occur at conserved positions in the proteins (Mooney et al. 2002; Miller and Kumar 2001). Although there is - to our knowledge - currently no general theory on the emergence of genetic diseases, one would nonetheless not have suspected that biological processes that have emerged early in evolution should be most vulnerable to them. Disease causing mutations should affect fitness and should therefore be lost over time. Thus, over extended evolutionary times, one could expect that genes that are subject to such mutations could become optimized to reduce these detrimental effects. However, since this is apparently not the case, one can conclude that genetic diseases are an inescapable component of life.
—
“A more practical implication of our finding concerns biomedical research strategies. Given that over 90% of the disease genes have emerged before the bilaterian radiation, it seems highly justified to use organisms that are evolutionarily very remote from humans, such as nematodes or insects, as models for studying the function of disease genes. Conversely, the prevalent use of mouse as a model system would not seem as pressing as it currently is, since there are less than 2% of disease genes which would not also be present in zebrafish, for example (although the functional roles of some of these genes may change over time - Liao and Zhang 2008). Furthermore, to understand the context of the biological processes in which a gene is involved, it may be advisable to use model organisms that represent the evolutionary level at which these genes emerged.”

Charts at link.

scrappy (usual for sci am) item on iq

“Still, when Plomin and his co-workers unveiled the results of their microarray study - the biggest dragnet for intelligence-linked genes ever undertaken - they were underwhelming. The researchers found only six genetic markers that showed any sign of having an influence on the test scores. When they ran stringent statistical tests to see if the results were flukes, only one gene passed. It accounted for 0.4 percent of the variation in the scores. And to cap it all off, no one knows what the gene does in the body.”
—
“ …microarrays that could detect 500,000 genetic markers—hundreds of times more than he had previously used. He and his colleagues got cheek swabs from 7,000 children, isolated their DNA, and ran it through the microarrays. And once more the results were disappointing.”
—
[speculative]
“In recent years, scientists have also published a number of studies in which they claim to have found distinctive patterns of brain functioning in people who score high on intelligence tests. Recently Haier and Rex Eugene Jung of the University of New Mexico surveyed 37 studies examining regional brain size or activity to look for an overall pattern to their results. As Plomin would have predicted, Haier and Jung found no one "intelligence spot" in the brain. Instead they identified a number of significant regions scattered around the cortex. Other studies have implicated each of these regions in different kinds of cognition. "It looks like intelligence is built on these fundamental cognitive processes, like attention and memory, and maybe language ability," Haier says.

“Along with describing the gray matter tissue that makes up the cortex, these studies also find the signature of intelligence in the white matter that links distant parts of the cortex to one another. People with high intelligence tend to have tracts of white matter that are more organized than other people. "The white matter is like the wiring," Haier says. "If you think about it, you know, intelligence really requires processing power and speed; the white matter would give it the speed; the gray matter would give it the processing power." ”

P.S. the html is a thoroughgoing mess.

related material
Intelligence: misuse and abuse of statistics
Franchise by examination; education and intelligence

the diseases of the father (and mother) .... passed through dna

“But new evidence suggests that parents may also pass on a common virus to their offspring hereditarily. Researchers estimate that one of every 116 newborns may have human herpesvirus 6 (HHV-6) infections that originated when the virus inserted its genetic material into that of their parents' DNA.”
—
“Scientists have long believed that they were infected in utero when viral particles from their pregnant mothers crossed the placental barrier. But a recent study published in Pediatrics documents a new mechanism for infection in which HHV-6 integrated into parental DNA is passed on at conception.

“Following childhood infection HHV-6 remains latent in the human body, although it may reactivate in immunocompromised patients, potentially triggering complications, such as pneumonia or encephalitis (inflammation of the brain and spinal cord). In less than 1 percent of all adults, the virus can also quietly slip its own DNA into the human genome—making it possible for mothers and fathers to pass HHV-6 to their offspring if these insertions are present in their eggs or sperm.”

free-piston engine and electricity generation for hybrids

Free-piston engine design.
Credit: Peter Van Blarigan, Sandia National Laboratory

“Free-piston engines aren't new: they were invented in the 1920s. But the increased recent focus on hybrid cars has led a growing number of research groups and automakers to start research programs to develop the technology. Unlike in conventional engines, there is no mechanical connection between the piston and a crankshaft (hence the name free-piston). Since the design allows for improved combustion and less friction, the engines could be far more efficient in generating electricity than either conventional generators or newer fuel-cell technology.”
—
“Van Blarigan's experiments suggest that these engines could be 50 percent efficient at generating electricity--close to the efficiency of hydrogen fuel cells and much more efficient than conventional generators. Free-piston engines are efficient in part because they have fewer moving parts than conventional engines do. The engine configuration also makes it practical to tune the engine so that the fuel in a combustion chamber burns very quickly. Faster combustion allows the engine to get more work out of a given amount of fuel, improving efficiency. It can also improve emissions.

“The free-piston design can also allow the engine to be instantly optimized for different fuels, such as hydrogen, natural gas, ethanol, gasoline, and diesel. Ideally, drivers could use whatever fuel is cheap and readily available.”

claims that solar pv makes another step forward

The following type of technology, in theory, goes back nearly 50 years. It is now making steady, but slow, progress over the past few years. As usual, these advances tend to be over-hyped; this is not the first such material arrangement of this type under investigation.

From Synthesis and Spectral Properties of Nanocrystalline V-Substituted In₂S₃ [indium sulphide],
a Novel Material for More Efficient Use of Solar Radiation. Image: acs.org

“Current photovoltaic (PV) devices and photocatalysts can use solar light through a process in which the absorption of one photon by a semiconductor leads in the latter to the promotion of an electron from the valence band (VB) to the conduction band (CB) with the subsequent production of electric current or chemical reactions. Within this mechanism, photons with energy lower than the forbidden band gap width E_g cannot be used. In recent years it has been proposed that the insertion of an additional level (the intermediate band, IB) in the forbidden gap could provide an additional path for attaining the same final excitation result through the absorption of two photons with energy lower than E_g, similarly to what happens in natural photosynthesis [...]” [Quoted from acs.org]

“Today's solar cells absorb only visible light, wasting the infrared that makes up half of the Sun's output that reaches Earth. But a new material developed in Spain can absorb infrared too, and should make it possible to hike the power solar cells can produce, say researchers.

“Conventional solar cells are based on a semiconductor such as silicon. But their inability to soak up infrared gives them a theoretical absorption limit of just over 40% of solar energy. In practice, they only absorb about 30%..”
—
“Their idea was to create a kind of energy "stepping stone". Instead of having to jump to the higher energy level in one go, electrons can absorb a low-energy photon and then wait at an intermediate energy level until another arrives to let it complete the trip.”

Semiconductor elements in the Periodic Table. Image: jxcrystals.com

“The new material, though, can harness both visible and infrared photons, so it has a theoretical maximum efficiency of 63%, its creators say, and should give significantly better real-world performance [than silicon].” [Quoted from newscientist.com]

Original article available here for $25!
Long abstract available here.

background briefings
photovoltaics (solar cells)

claim of producing hydrogen locally at normal temperatures - also, algae to petrol/gasoline

It’s getting ever more difficult to keep up with the progress in material sciences, and with checking the veracity of the deluge of claims. Here are two from this week.

“Currently available electrolyzers, which split water with electricity and are often used industrially, are not suited for artificial photosynthesis because they are very expensive and require a highly basic (non-benign) environment that has little to do with the conditions under which photosynthesis operates.” [Quoted from web.mit.edu]

I’m not sure how he intends to store the hydrogen in any useful quantity.

“Sapphire Energy announced today they have produced renewable 91 octane gasoline that conforms to ASTM certification, made from a breakthrough process that produces crude oil directly from sunlight, CO2 and photosynthetic microorganisms, beginning with algae.”
“Sapphire’s scalable production facilities can grow easily and economically because production is modular, transportable, and fueled by sunlight - not constrained by land, crops, or other natural resources.”
—
“Products and processes in this category differ significantly from other forms of biofuel because they are made solely from photosynthetic microorganisms, sunlight and CO2; do not result in biodiesel or ethanol; enhance and replace petroleum-based products; are carbon neutral and renewable; and don’t require any food crop or agricultural land.” [Quoted from sapphireenergy.com]

speculative: claimed new fuel-cell battery combination - which i don’t fully get!
[Original article in the Royal Society of Chemistry Journal.]

Claims to be taken with caution.

This item is being reported in various places with a degree of confusion. The technology is alleged to produce a useful energy at a density higher than petrol (gas) or diesel, and at an order of magnitude (ten times) higher than lithium battery technology.

The claim seems to be that this fuel-cell battery combination can be charged like an ‘ordinary’ battery and, when the charge is run down, the combination becomes a fuel cell. The fuel cell/battery cannibalises energy in some manner from its vanadium-boride anode, as it then acts as a fuel-cell. The anode can then be replaced., for instance at a garage in the manner of a petrol fill-up, and the anode can then be returned to functionality.

There are also suggestions that other combinations, including lithium and aluminium-[aluminum]-based systems, can be developed in this direction.

I get the impression that the reports I have seen so far are written by authors who do not fully understand the claims, and I certainly do not have a good outline grasp of the system!

So, I am linking this report for others to look at, without much confidence that I understand it!

“Energy capacity comparison of gasoline (petrol), hydrogen and electrochemical energy sources. The intrinsic energy of gasoline yields a maximum practical efficiency of 30% due to Carnot and friction losses. Air fuel cells do not have this Carnot inefficiency, and have practical capacities instead constrained by overpotential losses, and the requisite volume of the air anode and all other cell components. Volumetric capacity of liquid H2 is constrained by its density of 0.0708 kg L-1. Shaded superimposed on solid, colors, compare intrinsic and practical capacities.”

related material
Fuel the web address for the article above is
https://www.abelard.org/news/lite0808.php#fuelcell_battery_combination_300708

email email_abelard [at] abelard.org

© abelard, 2008, 04 august
all rights reserved

variable words
prints as increasing A4 pages (on my printer and set-up)