* 21 entries including: power grid infrastructure, THE MAKING OF THE FITTEST, radiation therapy versus the war on terror, indian tribes ascendant, reliable replacement warhead, cheap inhalers for administering drugs, arguable food politics, sudden infant death syndrome, artificial sweeteners, driver's license format controversy, machine translation techniques, proxy servers versus censors, geo-engineering against global warming, & Kennedy assassination.
* THE MAKING OF THE FITTEST (4): As mentioned in the previous installment, there was a period early in the 20th century where biologists were a bit skeptical of Charles Darwin's idea of slow evolution though gradual changes. One of the skeptics, a pioneering geneticist named R.C. Punnett, was interested in mimicry in butterflies -- the tendency of some butterflies that taste good to imitate the color patterns of butterflies that taste bad, discouraging predators.
In the course of his studies, Punnett wondered how long it would take natural selection to propagate an advantageous trait through a population and how long it would take it to eliminate a disadvantageous trait. He worked with a mathematician named H.T.J. Norton to do the calculations -- and the results showed that the number of generations was actually surprisingly small.
In modern terms, the basis of such calculations are what are called "selection coefficients". Suppose a "normal" member of a population of one species can produce 100 offspring. If a mutant variant can produce 101 offspring with a level of health equal to that of the normal member, then the mutant has a selection coefficient of +0.01. If a mutant variant can produce only 99 offspring with a level of health equal to that of the normal variant, then the mutant has a selection coefficient of -0.01. Norton's calculations showed that if eight members of a population of 1,000 with a mutant trait had a selection coefficient of +0.01 relative to the rest of the population, then the number of individuals in that population with that trait would be more than 90% in 3,000 generations. If the selection coefficient was +0.1, then it would only take 300 generations to take over.
Traits themselves tend to compound as well. Suppose individuals in a population get a selective advantage from being bigger. A change of 0.2% -- two millimeters for a one-meter-long plant or animal -- would be imperceptible from one generation to the next, but with compounding it would increase size by 50% in 200 generations. Such is the power of "compounded interest".
* This is all very interesting, but mathematical analysis simply shows what can happen given basic assumptions, not actually what does happen, which has to be observed in the real world. The difficulty is that it's very hard to pick out slight differences from one generation to the next, since individuals vary from one another. There are well-defined statistical methods to determine the degree of confidence in samplings -- the details aren't particularly interesting here, enough to say that the larger the sample and the bigger the change being measured, the higher the confidence.
That means the best-documented cases of natural selection being observed in the wild occur when selection is strong and rapid. The classic example is the British peppered moth. In the 1840s, a dark form of the well-know light-colored peppered moth was first observed by naturalists -- at roughly the same time that the Industrial Revolution was spreading soot over the landscape. In about 50 years, from 1848 to 1896, the dark peppered moth predominated, reaching a total of about 98% of the population of moths in the most polluted areas. Obviously, the light form was less well camouflaged than the dark form in areas where everything tended to be grimy, making the light moth much more vulnerable to predators, mostly birds. The British scientist J.B.S. Haldane estimated that the selection coefficient of the light moth was about -0.2. That's a pretty big selection coefficient, as it should be given the rapid adjustment in the moth population.
Incidentally, although the peppered moth is a classic example of natural selection, it is also one of the most heavily criticized. One of the later investigators, Bernard Kettlewell, performed experiments in the 1950s that suffered from a number of flaws, for example placing moths on tree trunks despite the fact that they don't usually perch there. This error was aggravated by texts that showed obviously staged photographs of dark and light peppered moths on tree trunks.
However, the controversy is a tempest in a teacup. The rise and fall of the peppered moth relative to industrial pollution was already well established, and the differential predation of light versus dark moths remains the obvious driving force. Indeed, one of the criticisms of Kettlewell's work -- that he didn't realize that birds see into the ultraviolet, and so a moth camouflaged to a human might not be camouflaged to a bird -- evaporated when it was determined that the camouflage of the moths worked just as well in the ultraviolet as it did in the visible light range. Accusations that Kettlewell fudged his data haven't been validated by careful reexaminations of his work.
In any case, Kettlewell's experiments are old news. Clean air acts were passed in the UK at about the same time that Kettlewell was performing his experiments. Since that time the British landscape, both rural and urban, has become vastly cleaner. The result is that light-colored peppered moths once again predominate, with the dark form all but becoming extinct. [TO BE CONTINUED]START | PREV | NEXT
* INFRASTRUCTURE -- THE POWER GRID (12): The urban power grid is complemented by an urban lighting grid. Without street lights, the night would be more oppressive and no doubt less safe, and towns wouldn't sparkle the way they do out of an airliner window at night. They do annoy astronomers who complain about the "passing of the night" from light pollution.
Once upon a time, urban lighting was provided by a gas lamp network, kept in operation by teams of "lamplighters". Late in the 19th century "carbon arc lamps" were introduced for public lighting; they produced light by running an electric arc between two carbon electrodes. They were a high-maintenance item and still required lamplighters to kick-start them, as well as keep them going. The introduction of tungsten-filament incandescent bulbs finally put the lamplighters out of a job, with an entire network controlled by the flip of a central switch.
In the 1950s and 1960s there was a push towards fluorescent street lighting, but modern streetlights use mercury-vapor bulbs, which generate a bluish light, or sodium-vapor bulbs, which generate an orange-colored light. In either case the light is generated by running an electric current through a hot gas of metal atoms (mercury or sodium as appropriate). Metal-vapor bulbs are more efficient than earlier street lighting technologies, converting more electricity to light and less to heat.
There are actually two types of sodium-vapor bulbs, low pressure and high pressure. Low pressure bulbs are more efficient and generate a deep orange color. High pressure bulbs are less efficient and generate a broader range of light. Astronomers tend to lobby for low pressure bulbs, as well as light fixtures that direct as much of their light as possible downward, instead of letting it leak up into the sky -- which wastes power anyway. The type of bulb and its power rating are generally labeled on the lamppost. The lamp is automatically turned off and on by a photocell on top.
Aging metal-vapor lamps have a tendency to cycle on and off. They will cool and stop radiating light; when they go off, a filament turns on to make them heat up again, to turn back on and start the cycle again.
ED: At least around here, side streets into residential areas usually don't have lampposts, with lighting provided by individual lights on a post outside the home. The result is much more muted and friendly lighting. Folks seem reasonably conscientious about replacing the bulbs when they go out. [END OF SET 6]START | PREV | NEXT
* GIMMICKS & GADGETS: It's been 30 years since the first installment of George Lucas' STAR WARS series of movies was released, and the US Postal Service (USPS) is commemorating the event by painting 400 maildrops across the USA to look like the courageous little robot R2D2. The USPS is also selling a commemorative stamp and running a video clip online featuring R2D2 and his fussy associate C3PO. It might have been amusing to wire the mailboxes to make beeps and whistles when the door was opened, but it wasn't done.
* An Italian firm has introduced a new RFID system for boaters that in principle eliminates the hassles of finding harbor accommodations. In the "MarPark" system -- the "Mar" is for "mare", Latin / Italian for "sea" -- boaters can make reservations in advance online, specifying dates and what services will be needed. When a boat arrives, it hooks up to a "smartbuoy" that includes an RFID reader, with confirmations sent via text messaging to the boater's cellphone. The scheme not only is convenient for boaters, it is also friendlier to the environment, since the smartbuoy hookup eliminates the need to drop anchor and chew up the seafloor.
* On a personal basis, I saw a cheap made-in-China toy at the supermarket and had to pick it up. It looked a bit like a cheap small plastic flashlight, except that it terminated in a transparent polyhedron with a paddle vertically mounted in it. The paddle was studded with LEDs around the edges -- pressing the switch on the side made the paddle spin rapidly around, with the LEDs producing green, yellow, blue, and red rings of light as they zipped around in circles. The LEDs were pulsed on and off to vary the lighting pattern.
I definitely had to categorize the toy as being in the "completely useless" category, and it's also basically a "one trick pony" even as a toy, but every now and then I just have to press the switch and watch the dazzling patterns. I also had to think there was somebody in China or Taiwan who had some real fun thinking the silly thing up.BACK_TO_TOP
* IF YOU'RE HOT YOU'RE HOT: With the arrival of the 21st-century "global war on terror", the authorities have had to climb up a learning curve, sometimes running into unexpected difficulties. According to an article on SCIENTIFIC AMERICAN online ("'Hot' Patients Setting Off Radiation Alarms" by Jane Sutton), the attempt to set up radiation-detector security systems to spot terrorists carrying a radioactive "dirty bomb" has run into a slight obstacle: there are plenty of ordinary people walking around whose bodies are radioactive enough to trip such detectors. The issue is that radioactive materials are commonly used in medicine as tracers or therapy, with 60,000 Americans a day being given such treatments. The radioactive materials administered to them do not represent a threat to them or anyone else, but the patients can still be "hot" enough to trip radiation detectors for anywhere from a day to three months after treatment.
Since the attacks on the US on 11 September 2001, the US Department of Homeland Security has issued more than 12,000 hand-held radiation detectors, mostly to Customs and Border Protection agents at airports, seaports and border crossings. Sensors are also used at government buildings, as well as major public events that might make attractive targets for terrorists.
In 2003, New York City police stopped a bus that set off a radiation detector when it went into a tunnel, only to find a passenger who had recently undergone therapy with radioactive iodine for a thyroid condition. That same year, the US Nuclear Regulatory Commission then issued a recommendation for doctors to warn patients that they may set off alarms after being given radiation treatments. However, the problem continues, more recently in the case of a British visitor to Orlando in Florida who had also undergone therapy for a thyroid condition being stripped-searched -- though for that was extraordinary, since a polite questioning usually clears things up in such cases, suggesting the authorities found the subject uncooperative. A radiation detector more capable than the handheld units can be used to identify the precise radioactive isotope found in the subject if necessary.
The nuclear power industry has long been aware of the issue. Nuclear power plants are monitored by radiation detectors, and workers at such facilities who have undergone radiation treatments have to make sure that supervisors and security know about it. Doctors are now beginning to issue cards to patients who have undergone radiation treatments that detail what radionuclides were administered and in what quantity. Hopefully that will allow any problems that arise to be resolved without a strip search.BACK_TO_TOP
* INDIAN UPRISING: The news a few months back that the Seminole Indian tribe had purchased the Hard Rock Cafe chain made headlines, and was all the more surprising since a few decades past the Seminoles, like most American native tribes, were impoverished. However, as reported in BUSINESS WEEK ("Parlaying Casinos Into Empires" by Christopher Palmeri, 26 March 2007), the tribes are now demonstrating a surprising amount of economic and political clout. Half the answer is simple: gambling. Although some of the tribes have resisted setting up casinos on their reservations, disliking the kind of drunken and ill-behaved crowd casinos might attract, many tribes did so and have found them profitable. So profitable, in fact, that tribes have been able to buy up banks, shopping malls, a mutual fund -- and trendy cafe / hotel chains.
The other half of the answer is less straightforward: the fact that tribal reservations are to a large degree sovereign nations. If a tribesman commits a crime and seeks refuge on a reservation, state or Federal authorities have to negotiate extradition with the tribal council to get their hands on him -- and the tribes are also not subject to taxation or the full range of US business regulations, which is why they got into casinos. Non-tribal competitors call this an unfair advantage, though Indian spokesmen shoot back that this was the agreement the US government made with the tribes. Given that the tribes were long handed deals that everyone knows were shabby, on occasion being shoved off reservations and relocated to less valuable lands, the spokesmen claim this is only fair, and that the Federal government cannot break any more promises.
That line of reasoning is impossible to sensibly argue, but where it gets more complicated is in the fact that the tribes can buy up land outside of their reservation and ask the Feds to hold it "in trust", in effect making it legally part of the reservation, held to the same rules (or lack of them). In New York state, the Oneida Nation has expanded from running two casinos to operating five golf courses, two marinas, over 700 hotel rooms, an RV park, a string of gas stations, a national weekly newspaper titled INDIAN COUNTRY TODAY, and even an animation production company. Local gas station operators couldn't compete with tribal gas stations selling gas and cigarettes tax-free and had to sell out. Counties are unhappy about the loss of tax revenues.
The rising political and economic power of the tribes makes them hard to fight. In 2006, the tribes contributed $7.4 million USD to political campaigns, and have strong lobbies in Washington DC. The Seminole Nation obtained financing to pay over $2 billion USD for the Hard Rock Cafe chain, and have major plans for expansion -- including on other Indian reservations. The Hard Rock Cafe operation, incidentally, will work as a normal taxpaying corporation, since many of the facilities are in big cities where the tribe cannot make any claim to sovereignty.
The Chickasaw Nation of Oklahoma is working on an even more interesting business venture. Working with the Chinese Nanjing Automobile Group, which obtained the rights to the MG automotive line, the tribe plans to open up a plant in Oklahoma and assemble MGs built from parts obtained from Nanjing and the UK. Although the tribe wants the property for the plant to be held "in trust", there's not a lot of resistance because investors will get favorable depreciation rates, and because the factory will hire hundreds of non-Indian workers.
As far as the protests go, Ray Halbritter, chief (executive officer) of the Oneida Nation, replies: "For all the years we lived in poverty, we had no complaints -- until we got successful." Says Max Osceola JR, a representative of the Seminole Nation: "Our ancestors sold Manhattan for trinkets. We're going to buy Manhattan back, one burger at a time."
* A related article in THE ECONOMIST ("The Last Shall Be First", 14 April 2007), paints a somewhat different picture of the same scene. Some tribes are indeed very wealthy, for example the little California Morongo tribe, which runs a casino operation in the Palm Springs, California area featuring a sleekly modern Vegas-style hotel-casino with 27 floors and 2,000 slot machines. The 775 adult members of the tribe get a portion of the proceeds, estimated at $15,000 USD a month minimum.
Alas, overall the tribes still remain poorer than the US population at large. It is the small tribes near Los Angeles (like the Morongo) and New York City (like the Pequot and Mohegans) that are raking in the money. The Hualapai tribe in Arizona tried to run a casino, but it was hopeless since Las Vegas is a relatively short drive away. The tribe has engaged in some successful ventures and has big hopes for a "skyway" built over the edge of the Grand Canyon, recently unveiled with much fanfare. However, the tribe still remains largely poor, unemployed, unhealthy, and saddled with high rates of alcoholism.
The article also painted a more ambiguous picture of the rights of tribal councils versus state authorities. The states have some ability to tax operations on tribal reservations, and Arizona and California have figured out mechanisms to increase the tax bite. On the other side of the coin, some states are liberalizing their gambling laws so that non-Indians will be able to compete more effectively.
The big money enjoyed by the prosperous tribes, as indicated above, is creating antagonism, and the lobbying money also mentioned above was not always wisely spent, for example going into the pockets of the notoriously corrupt Washington DC lobbyist Jack Abrahamoff. While the tribes are happy at their new-found fortunes, many are suspecting that the good times might be over faster than anyone expects.
ED: The Spokane Nation has a large reservation near my old hometown of Spokane, though not as large as the Colville and Yakima reservations to the west in the state of Washington. My brother Terry dated a Spokane Indian femme for a while who looked like a Hollywood idea of an Indian princess. She was a very pleasant, even somewhat shy girl, but tragically she was later killed in a light aircraft crash.
The Spokane Nation was actually prosperous long before casinos became fashionable, since uranium had been discovered on the reservation and the proceeds from mining were shared among members of the tribe. I believe the Spokanes do run some gambling, but the Coeur d'Alene tribe in North Idaho to the east has the most high-profile casino operation in the Spokane area, or "Inland Empire" as they like to call it. My mother tells me the tribe is generous to civic causes in the region.
Incidentally, although the term "Indian" is regarded as politically incorrect, tribal websites have few problems with it and it's even commonly labeled on tribal flags and logos. From the evidence I have come to the conclusion that insistence on the use of the awkward "Native American" term is mostly posturing by palefaces. When the Federal Bureau of Indian Affairs -- whose current boss, incidentally, is a Wisconsin Oneida -- becomes the Bureau of Native American Affairs, I will reconsider my position on the matter without hesitation.BACK_TO_TOP
* THE MAKING OF THE FITTEST (3): One of the difficulties in accepting evolution by natural selection is that it seems to defy the odds. How could random mutations in the genomes of life-forms have produced significant changes that benefited their hosts? As it turns out, the odds don't seem to be as outrageous as they might seem at first.
Albert Einstein was once supposedly asked: "What is the most powerful force in the Universe?" He replied: "Compounded interest." A small amount of capital left in the bank drawing interest and increasing its size will sooner or later become a great fortune.
Darwin observed something equivalent to this notion in the selective breeding of pigeons -- whose care and cultivation he had originally taken up as an experiment, but which became a passion. He observed how an enormous range of variations in pigeon form had been created from, as he believed, a single wild species, the rock pigeon. Not all pigeon fanciers believed so, but he observed "that most skillful breeder, Sir John Sebright, used to say, with respect to pigeons, that 'he could produce any given feather in three years, but it would take him six years to obtain head and beak.'" Sebright in effect simply bred to accumulate small changes until he got what he wanted.
In Darwin's time, not everybody bought the idea of evolution by small continuous changes. His prominent ally Thomas H. Huxley thought that natural selection worked, but that it worked on major, very significant changes between generations -- that is, that a prehistoric horse with three toes might give birth to a "improved" horse with one. This notion was generally referred to as "saltationism".
One of the reasons for this difference in opinion was that the mechanisms of heredity were barely understood at the time. In the 1860s, an Austrian monk named Gregor Mendel opened the door to the understanding of heredity by observing the patterns of inheritance among generations of pea plants, demonstrating the rules by which the plants inherited flower colors, pea colors, and other traits. However, for various reasons nobody paid much mind to his research at the time, and Mendel's findings didn't come to the attention of the scientific mainstream until the year 1900, decades after his death.
Even then his work was misunderstood. A British biologist named William Bateson, one of the founders of the modern science of genetics, believed Mendel's work demonstrated saltationism, since the traits Mendel worked with were fairly obvious and drastic. Actually, Mendel had specifically focused on pea plants because he had noticed they had sets of clear and distinct traits -- making pea plants a very good test subject for studies of basic heredity, but they were not necessarily all that representative of other organisms.
A Harvard biologist named William Castle was persuaded by Bateson's ideas and decided to test them through selective breeding of a species of rat known as the "hooded rat" over many generations. The hooded rat has a pattern of light fur on its body and dark fur over its head; Castle and his students found, somewhat to their surprise, that they could change the dark coloration pattern by slow increments to produce a dark stripe down the back, continuing until they had rats with no light fur at all. Maybe the idea of slow, incremental changes wasn't so unrealistic after all. Darwin, with his body of knowledge of pigeon breeding, might well have thought, though he would certainly have been too polite to say: "I told you so." [TO BE CONTINUED]START | PREV | NEXT
* INFRASTRUCTURE -- THE POWER GRID (11): In the USA, the secondary electrical distribution circuits that link directly into a residence or business usually provide 120 or 240 VAC, using two hot leads and a neutral. Large appliances like the electric stove or clothes dryer get all three leads to provide 240 VAC, while the rest of the household system gets a neutral and one of the hot leads to obtain 120 VAC.
The secondary circuit is strung along the power poles or sometimes along buildings on ceramic insulators that look like big spools. In some cases there are three sets of spools to carry the three lines; in other cases the two insulated hot lines and the bare neutral line -- since it's at ground potential, there's no reason to insulate it -- are wound together in a "triplex" format and carried on single spools.
In a downtown commercial district, the secondary circuits may be fed by multiple transformers to make sure that losing a transformer won't shut down the entire area -- though in such cases, a serious fault in the secondary network may pull down the entire secondary grid. In a residential area, a single transformer supplies power to a specific set of houses.
One of the most important elements of the residential power grid is the electric meter. In fact, it was one of the items that made the power grid possible by ensuring that there was a sensible way to bill users for the power they consumed. An electric meter is just a special electric motor whose rate of rotation depends on the power flowing through it; the well-known spinning disk in the meter is part of the motor. Clock dials in the meter count up the rotations of the disk. Each month a meter reader checks the dial positions and writes them down, with the previous readings subtracted from the new readings to give the power consumption. Newer meters don't have moving parts and may even eliminate the need for a meter reader, sending their readings to a central station over wireless, or even over the power lines themselves.
* In more modern housing developments, the secondary circuits are linked to houses through underground conduits. The idea is nothing new, with underground distribution having been common in big city centers for over a century. Traditionally, transformers and switches were placed in manholes, or in underground vaults. Sometimes underground gear is sealed in waterproof casings so it will keep on working even when the underground system is flooded. The power lines are pulled through conduits, with the individual lines wrapped in insulation of oil-soaked paper.
Modern suburban underground distribution systems take a cheaper approach, with the transformers and switches in aboveground metal cabinets, which are usually painted green, though there's a tendency to decorate them with artwork these days. The lines, which are bundled into one plastic-insulated sheath, are laid down in trenches.
There's not much to see with an underground power distribution system, although it is possible to spot power poles where the bare lines are mated to insulated lines that then dive into the earth. A bare line and insulated line are mated by an item called, believe it or not, a "pothead", which simply makes sure water can't get inside the insulation. The lines feeding the potheads are usually rigged with fuses and surge arrestors, with the wiring tagged or color-coded to allow linemen to figure it out.
Power companies tend to prefer aboveground lines since they're several times cheaper to build. Advocates of underground lines point out that they won't be pulled down by an icestorm or by falling tree limbs. However, when there's a fault in an underground line system, it's much more trouble to track down and repair. [TO BE CONTINUED]START | PREV | NEXT
* NEW NUKES: As discussed in THE ECONOMIST ("Newer & Fewer", 10 March 2007), if the end of the Cold War didn't result in peace breaking out all over, it still has had its benefits -- for example, a reduction in the stockpile of nuclear weapons maintained by the US. The irony is that doing so involves building new warheads. On 2 March 2007, the US National Nuclear Security Administration, the component of the US Department of Energy that handles bombs, announced the winner of a competition to design a "Reliable Replacement Warhead (RRW)". Funding hasn't been provided yet, but if Congress gives the go-ahead, work on the RRW may start in 2008.
Congress may well grant approval, since the RRW was partly the idea of Congress to begin with. The Bush II Administration wanted to build a nuclear bunker-busting bomb, but Congress was cool to the idea -- it might be too tempting to use the thing, particularly since the Bush II Administration seemed overly inclined to resort to force. It also would require testing, breaking the moratorium on test shots currently in effect.
The RRW design that was selected was produced by the Lawrence Livermore National Laboratory in California, over a rival design from the Los Alamos National Laboratory in New Mexico. It is a modification of a design that was tested four times in the 1980s, but was never put into production since it was judged too big and heavy. Now it seems well-suited to the RRW role. The modifications basically consist of changes to reduce cost and complexity while increasing safety and reliability; the subsystems that will be changed can be tested without actually performing a test blast. Some features of the rejected Los Alamos design, for example to prevent a stolen weapon from being used by terrorists, will be included in the Livermore RRW.
During the Cold War, warheads tended to small and complicated in order to put as many of them as possible on a single missile. Arms limitation treaties now mean that a single warhead is the norm, and so instead of building them small and tricky, they can be built bigger and much more robust. The ensured reliability of the RRW will allow stockpiles to be reduced further, since there won't be as big a need to maintain a margin of weapons to ensure sufficiency.
While the RRW does not seem to be very controversial, the Bush II Administration's plan to consolidate and modernize US weapons-making facilities into a "Complex 2030" is causing uneasiness. The new infrastructure will be able to turn out plutonium "pits" -- bomb cores -- more rapidly and will be more economical to operate over the long run. However, over the short run it will require massive investment. Los Alamos stands to be the big loser in the change, since the lab has been plagued in recent years by security and management problems, and has been suffering from brain drain as the lab's expertise retires or quits. It was traditional US policy to maintain two weapons labs to provide some competition, but now that the nuclear arms race is over the redundancy seems simply wasteful.
The Bush II Administration has been prodding Congress to make decisions, pointing out that the US has been accelerating the dismantling of warheads to meet the treaty commitment with Russia of 1,700 to 2,200 strategic warheads deployed by 2012. The administration also points out that the other big nuclear players -- Russia, China, Britain, and France -- are also modernizing their arsenals. However, Congress seems inclined to think the matter out carefully.BACK_TO_TOP
* INHALERS FOR THE DEVELOPING WORLD: Technophiles tend to be infatuated with the latest whizzy technology, but sometimes that mindset tends to overlook the fact that technology can advance by doing something simple and cheap. As discussed in an article on MIT TECHNOLOGY REVIEW Online ("A Four-Cent Inhaler" by Tom Mashberg), one interesting example is a new inhaler for administering vaccines and drugs.
The World Health Organization recently provided an estimate for the total cost of immunization programs in the world's 72 poorest countries over the next decade, with the bill coming to $35 billion USD. The analysis showed that two-thirds of the cost was actually swallowed up by delivery, not the vaccines themselves. Syringes are very cheap, but their use has safety implications and requires a bit of training and supervision.
Vaccinations using inhalers can be conducted by minimally-trained staff, but inhalers have traditionally been expensive, with up to 20 parts and a cost of 40 cents each. Cambridge Consultants of Cambridge, UK, has now introduced a four-cent inhaler. It is intended to administer powdered vaccines and drugs, and features a shape that promotes a cyclonic airflow that picks up and efficiently aerosolizes the powder. Cambridge Consultants claims that it is substantially more effective than traditional inhalers as well.
It will only work with powders, but since ozone-depletion worries have led to bans on the propellants used in traditional inhalers, pharmaceutical companies have been aggressively working on dry-powder inhalable forms of everything from insulin to flu vaccines. The inhaler is easy to use, being shipped as a container carrying the vaccine or drug to be administered in a foil pouch. Unfolding the inhaler punches open the pouch, making the device ready to use. The inhaler could even in principle be mailed to citizens for use at home.
Cambridge Consultants says that five pharmaceutical and drug-delivery companies are evaluating the inhaler. If one or more companies decide to adopt it, clinical trials would then be required, which could take up to four years. However, for a flu vaccine the trials could be accelerated and completed in a year.BACK_TO_TOP
* FOOD FIGHT: It is a simple observation that all that glitters is not gold. For example, as discussed in THE ECONOMIST ("Voting With Your Trolley", 9 December 2006), consider the notion that family supermarket purchases can become environmental or social statements. Grocery shoppers can now "buy organic", or participate in the "Fairtrade" effort, or focus on "local food". Such "food activism" gets a lot of press, but it has also attracted a lot of critics.
The organic food industry is the most prominent aspect of food activism: it's a big business, with sales of $30 billion USD a year. There is some variation in the definition of "organic food", but it can be generally regarded as crops grown with severe restrictions on the use of pesticides and fertilizers, and rejection of genetically modified (GM) plants. Crops are fertilized with manure and fields are rotated to keep them from being mined out. However, there are those who believe that organic food is oversold.
It may be nitpicking to respond to the GM bugbear by pointing out that many crop plants are wildly mutated from their wild ancestors and completely unable to survive without human care -- they're just as much "monsters" as gene-spliced foods. It may not be any more persuasive to point out there's no strong evidence that organic foods are better for one's health -- and indeed, most grocery shoppers who "buy organic" say it is mainly out of environmental concerns. That's where the real difficulty pops up: is organic food really "green"? It might seem so from its avoidance of pesticides and fertilizers, but Nobelist Norman Borlaug, father of the "green revolution" and a strong critic of organic farming, points out that high-tech farming has about three times the yield of organic farming. In other words, if all the planet's agriculture was organic, it would require three times the land, which would mean fewer forests.
The debate about organic farming goes on at other levels as well. Some advocates claim it requires less energy, particularly in the synthesis of fertilizers; critics reply that since organic farming is more labor-intensive and less productive, it ends up expending more energy than high-tech farming. In any case, only about a fifth of the energy expended in the food cycle, from farm to dinner table, is used to grow the food -- the rest is used up in processing and transport. The organic food movement also has critics on the inside, who believe the movement has been hijacked by big food corporations. With tens of billions of dollars of sales every year, it would have been impossible to keep the corporations out.
* The "Fairtrade" movement, promoted by the "Fairtrade Labeling Organizations (FLO) International" group, is more focused on producers, the aim being to sell FLO-certified foods at a premium -- say, about five cents more for a pound of coffee -- with the higher margin being provided to poor developing-world food producers to boost local agricultural programs. In effect, it's an agricultural subsidy program paid for directly by food consumers. The market in Fairtrade foods is only a fraction of that for organic foods, but it is growing rapidly.
Of course, to most economists, the word "subsidy" is like waving a red flag, and Fairtrade has been strongly criticized as counterproductive. According to the economists, the reason that coffee prices are painfully low for producers is that there's overcapacity -- too many coffee growers in the market. Providing a subsidy will only attract more growers into the market, which will drive down prices further. Wouldn't it be wiser, so the economists argue, to persuade coffee growers to change crops? FLO International officials say that may not be practical for many growers, who are simply operating too close to the margin to be able to switch horses, so to speak, and handing them a premium would actually give them a greater ability to switch to a less cutthroat market.
There are also disagreements over FLO International's concepts for Fairtrade certification, which focuses on farm co-ops but not company or family plantations. Officials of the Rainforest Alliance, an alternative certification organization, claims this means that Fairtrade doesn't help the majority of farm workers. The Rainforest Alliance is more flexible, focusing on training, consultation, and access to loans. As with Fairtrade, an RA sticker may command some attention from consumers, but unlike Fairtrade there's no attempt to pass a premium down to producers.
That premium isn't as big as it seems anyway, since much of the markup on Fairtrade products never reaches the producers, the bulk of it being pocketed by retailers. Some estimate that only 10% of the markup finds its way back down to the bottom of the pyramid. The end result is that there are those who are sympathetic to the principles of Fairtrade but feel is not much more than marketing hype in practice, and point to a major deal between FLO International and international food giant Nestle as evidence that Fairtrade has just become a marketing gimmick for big corporations. FLO International officials reject this argument, saying that there has been a reasonable compromise between the two parties that benefits both sides.
* The popular distaste for corporate power has led to the emergence of the third leg of food activism, local food. Local food doesn't have to be organic, it just has to be bought locally from small producers, bypassing corporate control. In principle, it means less markup in the middle of the food retailing chain, meaning lower cost to consumers and higher profit to producers -- which means that local food appeals as much to farm lobbies as it does to Greens. Greens also believe that local food reduces the "food miles" that the product has to be hauled to reach consumers, which should equate to less waste of energy and lower carbon dioxide emissions.
Again, the question is, just how real are these benefits? They are certainly arguable. In 2005, the UK's environmental and farming agency, DEFRA, published a report last year that slammed the local food movement heavily. It concluded that, for example, it was cheaper and more energy-efficient to buy tomatoes grown in Spain than raise them in heated British greenhouses. As far as food-miles went, the report added that the biggest component of energy usage in the transport of food is the trip from the supermarket back to the home. It's obvious in consideration that food is trucked to supermarkets in consolidated bulk loads, and then taken home a few bags at a time in a passenger vehicle. It's a bit less obvious that the consolidation of bulk food transport is so efficient that the report judged it likely that hauling around small lots of food locally actually uses more energy.
Lincoln University in New Zealand conducted a study that showed it was generally cheaper and more energy efficient to haul a range of agricultural products from that country to the UK than it was to grow the products in Britain, since New Zealand agriculture was so much more energy efficient. A countercritic might reply that New Zealander academics had a vested interest in coming to such conclusions, but that response cuts both ways: local food advocates have a vested interest in their own, in the form of trade protectionism.
As with all such arguments, it is difficult to sort through the noise and see where the truth actually lies. Likely the only real lesson is that the choices that consumers make at the supermarket may make them feel better -- but it is an illusion to believe them a serious substitute for action by governments and non-governmental organizations to deal with problems directly.BACK_TO_TOP
* THE MAKING OF THE FITTEST (2): Although the evidence strongly suggests that all the enormous changes that produced the remarkable icefish occurred in a process of natural selection -- and the evidence doesn't suggest any other physical process for how else it might have happened -- it still seems hard to buy that such changes could have occurred by chance mutations, taking place without a road map to the future. The icefish didn't decide to get rid of their hemoglobin genes: the genes broke on their own and it just so happened that the icefish got along fine, even better, without them. Even evolutionary scientists have a tendency to say things such as the icefish "invented" the antifreeze proteins, or they "deleted" the genes for hemoglobin production. The fish didn't invent or delete anything: they don't have the brains to add two and two to get four, they could have hardly have redesigned their own genome. Mutations occurred by sheer chance that turned out to be beneficial to those fish that possessed them; they won a throw of the dice in which they had no say or awareness.
The evidence for evolution has tended to be somewhat indirect, only acquiring weight through the accumulation of different lines of evidence. Since the 1990s, the DNA sequences of an increasing number of organisms have been decoded, providing a particularly significant new component to that body of evidence. The DNA evidence shows:
These themes will be discussed in later installments in this series. [TO BE CONTINUED]START | PREV | NEXT
* INFRASTRUCTURE -- THE POWER GRID (10): Transformers are a familiar sight in a residential electric power system. They're generally in the form of oil-filled finned "cans" on power poles that step down the distribution line voltage to the 120 or 240 VAC required by end-users. (Some big users will actually get 480 VAC.)
In the North America, there's generally only one "high side" connection since end-users typically get single-phase power, tapped from one phase line and referenced to neutral. Since Europeans tend to prefer to tap a phase from two phase lines, European transformers tend to have two high-side connections. Customers who require triple-phase have a triple-phase transformer -- or possibly three single-phase transformers, with each tapped into a different phase of the distribution line.
The "low-side" wiring usually connects directly to the transformer, elaborate bushings not being required for such low voltages -- though the wiring is insulated. In the US, a single transformer might feed three or four houses; Europeans prefer larger transformers, feeding 50 to 100 homes. The power rating is often stenciled on the side of a transformer, with the value given in "kilovolt-amperes", which, ignoring a bit of fine print, equates to kilowatts. Transformers range in power capability from 10 to 300 kilowatts.
Residential power networks have their own protective devices. Fuses are common and are usually in the form of cardboard tubes with a connection on each end, wired in series with the electric circuit. The tubes have a metal rod running down the center that melts when the current becomes too great. Since an arc may persist over the gap, the lining of the tube is designed to vaporize and quench the arc. This results in the fuse blasting open in the ends with a loud BANG -- which is why they're called "expulsion-tube" fuses. Everybody has heard a bang like this every rare now and then, and the popular mythology is that the transformer has blown up. That's not impossible, but it would be troublesome to fix, and so fortunately the fuse is almost always the culprit.
Since fuses don't always work, there's generally a second fuse in series with the first. The second fuse is more reliable and expensive, consisting of a tube full of pure quartz sand with a silver filament down the center. When the fuse overloads, the filament melts, with the quartz fusing into glass that quenches the arc. A silver-sand fuse is substantially more expensive than an expulsion-tube fuse, but the silver-sand fuse is designed to open at a higher level of current -- so the majority of the time the expulsion-tube fuse will blow first, sparing the silver-sand fuse.
The primary distribution line also features sets of switches at intervals. They are often in the form of "knife-blade switches", which are simple bars with a handle on one end and a pivot on the other that are flipped to make or break connections with contacts. (Mad scientists in old movies usually obtained their bolts of electricity to fire up a monster by flipping a dual knife-blade switch.) They're not used to open a hot circuit, they aren't designed to handle the arc: they're used instead to isolate parts of a line that's malfunctioned and been shut down at the substation, allowing the line to be brought back up by increments after the malfunction is isolated. Usually knife-blade switches are mounted high on the pole so only linemen can get at them, but some have a lever or crank at ground level -- which will be locked to prevent pranksters from doing themselves or others harm.
There are also automated switches called "reclosers", which are conceptually similar to the switches at the power substation but look more like small power-line transformers. They work much like the substation switches, with a switch that opens on command or automatically in an oil bath that quenches the arc. Like the substation switches, the reclosers don't have cooling fins since they don't dissipate power normally. They also can be distinguished from power-pole transformers because they have a set of bushings in and a set of bushings out -- not a set of bushings in and insulated residential lines out. Another big hint is that they are also sometimes handily marked with the label RECLOSER.
Such a device is called a "recloser" because, since faults are often transient, once tripped it closes again right away. If it trips again, it waits a bit and closes again. If it trips a third time, it waits longer and tries one last time. If that doesn't work, it stays open and a lineman has to reset it. It's the reclosing action that causes lights to flicker in a thunderstorm.
A power pole may also sport a bank of capacitors to balance power phase. Each capacitor is a metal box with the proportions of an oversized telephone book. Since capacitors can short out, they may have a fuse or recloser in series to protect them. [TO BE CONTINUED]START | PREV | NEXT
* SIDS EXAMINED: Every year in the USA, over 2,000 babies between two and four months of age who otherwise seem perfectly healthy are put to bed in a crib and never wake up again. Autopsies show no infection or trauma. The babies simply died, and nobody can explain the "sudden infant death syndrome (SIDS)".
According to an article in US NEWS & WORLD REPORT ("Solving The SIDS Mystery" by Nancy Shute, 13 November 2006), researchers are starting to get some ideas on what may be going on. A team from the Children's Hospital Boston, Harvard Medical School, and the University of San Diego School of Medicine autopsied 31 SIDS victims from San Diego. The results of this work were published in the JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION and suggested that these babies had a defect of the medulla, the part of the brain stem that controls autonomic body functions such as breathing and heart rate. The defect involved difficulties in responding to serotonin, the body chemical that regulates sleep and breathing.
Boys who died from SIDS seemed to have worse abnormalities than girls, which could well be correlated to the fact that boys are twice as likely to die from SIDS as girls. This study does not nail SIDS as the cause, however, since other studies have suggested liver or heart problems, and nobody is close to being able to detect in advance what babies are most at risk from SIDS.
The researchers do all believe that SIDS has a physiological cause and is not due to parental negligence -- though it is clearly linked to environmental factors. SIDS tends to kill babies who are put to sleep face down; or have cribs with soft bedding or comforters; or sleep in beds with adults. The belief is that whatever peculiarity these infants have, it makes them unable to respond when they can't breathe correctly, and they simply lie there and suffocate. Public education programs implemented from the early 1990s have pointed out these factors to parents, and as a result the number of SIDS deaths has fallen by half. Tackling the other half is going to take more work.BACK_TO_TOP
* SWEET TOOTH: An article from DISCOVER magazine from a few years back ("Hitting The Sweet Spot" by Jocelyn Selim, August 2005), took a close look at the world of artificial sweeteners. It's not surprising that it's a big business, but it is surprising to find out that artificial sweeteners are nothing new, and that they were initially found by accident. The first, saccharin, was discovered in the 19th century by two chemists at the Johns Hopkins University in Baltimore, who were tinkering with coal tars -- a nasty coal residue that was a great inspiration for chemists of that era, though a seemingly dubious source of a sweetener.
Aspartame was discovered in the 1960s by a medical chemist in Illinois who was working on a drug to deal with gastric ulcers, while sucralose was discovered in 1976 by a student at King's College London -- who was told to "test" some compounds by his head researcher but misunderstood him as saying "taste". Sucralose, incidentally, is promoted as "natural" because it's obtained from sugar itself, but the sugar is just a feedstock -- like saccharin, sucralose is so biologically foreign that it can't be digested and is simply passed inert through the body, providing zero food value. In contrast, aspartame is easily digested.
A large number of artificial sweeteners are known. The puzzling thing is why they all taste sweet, since they have wildly different chemical compositions and structures. An answer was proposed in 2001 by Charles Zuker, a neuroscientist at the Howard Hughes Medical Center. His tinkerings with the genomes of humans and mice indicated that they coded for 30 different taste bud receptors for "bitter" but only one, repeat one, for "sweet".
Biologists didn't have a problem buying off on this idea, since from the evolutionary point of view it would be nice to have a highly discriminating ability to detect toxins, while there's no drive to be so fussy about sweet-tasting substances. However, researchers working with sweeteners were dubious, since they knew that some artificial sweeteners in combination were much more powerful than the sum of parts, while factors such as caffeine can inhibit some artificial sweeteners. That seemed to argue for two receptors.
Zuker stuck to his guns, saying that he knocked out the gene for the sweet receptor in lab mice and the mice could then not distinguish sweet substances of any sort. But then, how could he explain the contradiction? Suppose, he suggested, that the sweet receptor had multiple binding sites. It took until 2004 for researchers at Senomyx, a company co-founded by Zuker, to prove this was the case, comparing it to a "gun with two triggers".
Understanding of the sweet receptor promises to bring the investigation of artificial sweeteners fully out of the age of hit or miss. Cyclamate is 45 times as sweet as sugar, aspartame is 180 times sweeter, saccharin is 300 times sweeter, and sucralose is 600 times sweeter. However, an improved aspartame derivative named "neotame" is 13,000 times sweeter, and other compounds have been found that are 100,000 times as sweet. The trick is to design a compound that binds more tightly to the sweet receptor.
The difficulty with all artificial sweeteners is that "artificial" word. Not one of them is a real substitute for sugar. Saccharin tends to trigger bitter and sour receptors and so it has a bitter aftertaste. Aspartame and neotame break down on store shelves and can't tolerate cooking. Sucralose has a good shelf life and can take the heat, but it just doesn't cook like sugar.
There's also the worries over effects on health. Food additives such as artificial sweeteners tend to be given a much more thorough examination than drugs, since the sweeteners generally don't have medical benefits to balance possible drawbacks. Despite that, all examination of common artificial sweeteners has given them a green light. Saccharin got a bad rap in 1981 as a possible carcinogen, but it was rehabilitated in 1997 when the study that fingered it turned out to have used rats prone to cancers in the first place. Medical experts still warn that all sweeteners, real sugar included, should be used in moderation. It is possible to get too much of a good thing.
* In related news, it has been discovered why cats, unlike dogs, have no interest in sweet foods: it's because they don't have sweet receptors and can't taste sugars. It's one of the consequences of having a meat diet -- the loss of the ability to detect sweetness costs them nothing -- and in fact they don't subsist well on sugars and starches.BACK_TO_TOP
* BUCK PRIVATES: One of the consequences of America's entry into the "age of terror" in the 21st century has been a series of new rules and regulations designed to make life more difficult for terrorists. However, citizens are beginning to wonder if some of these rules and regulations simply make life more difficult for everyone else without doing much to slow down terrorism. As reported in THE ECONOMIST ("Too Much Information", 24 March 2007), in 2005 the US Congress passed a bill that provided $81 billion USD for military spending and Asian tsunami relief. All that was straightforward, but that bill had a rider, the "Real ID Act", that hasn't proved so straightforward.
In the US, driver's licenses are issued by the individual states. The Real ID Act set national standards for driver's licenses, stipulating that a license could only be issued to drivers who could verify their identity; that the license have a "common machine readable technology"; and that it have "physical security features". The new driver's licenses were to introduced by 2008. Anyone who wanted to fly on an airliner would have to produce such ID.
Even the Department of Homeland Security (DHS) admitted that the cost of the change to the states would be up to a total of $14.6 billion USD, with direct costs to citizens of another $8.5 billion USD. The Federal government would only pick up a fraction of the tab. In addition, critics claim that the new driver's licenses are just a stealthy way to impose a "national ID card" on the American public and will contain too much sensitive personal data, making driver's licenses intrusive and a prime target for identity thieves. In fact, the way the Real ID Act was passed through Congress, as a rider on a major spending deal, was been seen by critics as stealthy in itself.
In early 2007, the Maine state legislature unanimously passed a resolution refusing to implement the new ID scheme. Since that time about half the states in the US have introduced or passed various resolutions against the Real ID Act. In response, on 1 March the DHS issued guidelines that more or less stated the new ID scheme would go forward as originally planned, though the schedule was relaxed a bit. No more financial help from the Federal government was offered, and as far as the privacy problems went, the guidelines helpfully suggested the states could deal with them on their own.
If this response was supposed to have placated the states -- which seems unlikely -- it certainly didn't, and legislation amending the Real ID Act is working its way through Congress. Apparently Americans are not quite ready to accept the idea that holding the line in the War On Terror implies demoting everyone to the status of buck private.BACK_TO_TOP
* THE MAKING OF THE FITTEST (1): Sean B. Carroll's 2006 book THE MAKING OF THE FITTEST takes an interesting approach to the examination of evolutionary science, using the DNA evidence obtained over the last few decades to draw a line under classic evolutionary theory. The book is worth summarizing here.
* When Charles Darwin published THE ORIGIN OF THE SPECIES in 1859, he included every single example he could find in roughly 20 years of work to demonstrate his theory that species emerged by the accumulation of random variations -- what we would call today "mutations", screened by natural selection forces in that those species with useful mutations would prosper and those with damaging mutations would die out.
There were some examples he didn't know about and which might have been a bit of a shock to him if he had. In 1928, a Norwegian biologist named Ditlif Rustad who was visiting isolated and frigid Bouvet Island in the South Atlantic discovered a very strange fish. It was pale, almost translucent, and most surprisingly it had pale, clear, colorless blood. A colleague named Johan Ruud visited the Antarctic regions on a whaling vessel at roughly the same. When the crew told him about such bloodless fish he thought it was a sailor's story, but when he got back to Norway he mentioned the tale as a gag to Rustad -- who replied: "I have seen such a fish." -- and handed him photographs to prove it. Ruud was fascinated, but had other things to do and more or less forgot about the matter.
His curiosity was reawakened two decades later when another colleague returned from the Antarctic with samples of the clear-blooded fish. Ruud asked other colleagues on trips to the region to keep an eye out for what the whalers called "devilfish" or "icefish". In 1953 Ruud went to South Georgia Island, directly to the west of Bouvet Island, and obtained samples of icefish to examine in detail. He published a paper describing the icefish in 1954, with the paper attracting a fair amount of attention since its conclusions were extremely startling: the icefish's blood contained no red blood cells.
About 15 species of icefish are known. They are part of a larger group of cold-weather fishes, the suborder "Notothenioidae", related to codfish and containing about 200 species. The icefish are very extreme variants of this suborder, being the only known vertebrates that do not have red blood. In all other vertebrate species, the blood is full of red blood cells, which are used to transport oxygen through the bloodstream. The red blood cells are loaded with a molecule named "hemoglobin", which is a composite of a protein named "globin" surrounding a core molecule named "heme". It is the heme component which actually binds with oxygen, and which gives blood its red color. The icefish do not have a trace of hemoglobin in their bodies.
* It wasn't until the 1990s that the story of the icefish was well understood. It was known before then that Antarctic waters had been cooling for over 50 million years, gradually driving fish species that couldn't stand the cold northward, leaving behind species that developed mechanisms to deal with the low temperatures.
One of the issues of surviving low temperatures is that the viscosity of body fluids increases, making it harder and harder to pump blood. One way of dealing with the viscosity problem is to cut the red blood cell count. Human blood is about 45% red blood cells by volume, while red-blooded Antarctic notothenioids have blood that's about 15% red blood cells by volume. The icefish have done this more than one better by not having any red blood cells at all -- in fact, their blood is only 1% cells by volume, in the form of white blood cells used by the immune system.
So how can an icefish still be alive? Because in compensation colder waters can absorb more oxygen -- in other words, all the icefish needs to pump is water to keep oxygen flowing to its brain and other organs. Water's still not as efficient as red blood cells in carrying oxygen, but the icefish keeps on going with larger gills; a bigger heart; a blood system with greater overall volume; and a network of capillaries under scaleless skin -- allowing it to soak up oxygen directly from the water around it.
The idiosyncrasies of the icefish are recorded in the patterns of their DNA. The genomes of their relatives have twin genes for production of globin, but in the icefish one of these genes is garbled into functionlessness by mutations and the other has simply disappeared. In addition, five of the icefish species also have a garbled and broken gene for production of "myoglobin", another heme-containing, oxygen-binding molecule found in muscles. Myoglobin binds oxygen more tightly than hemoglobin and is used to provide oxygen to muscles on demand; diving mammals like seals and dolphins have muscles that have very high proportions of myoglobin, allowing them to stay underwater for long periods of time, and making their muscles dark brown. The five icefish species that have the broken myoglobin gene have pale muscles and a pale heart.
Production of myoglobin doesn't seem to impose any strong penalty on icefish in itself -- if it did, all icefish species would have lost it by now -- but with the adaptations of icefish to obtaining more oxygen, it doesn't provide any real advantage, either. When the myoglobin gene broke in a part of the icefish population, in effect they didn't know it was gone, obtaining a slight advantage from not having to go to the effort of producing it to compensate for the disadvantages, if any, of losing it.
There are other unique and tweaky changes in the icefish. Cells make use of a class of structural proteins that form "microtubules" -- which in other vertebrate species tend to break down at low temperatures. All the notothenioids have microtubules that feature minor changes that ensure their low-temperature stability, the changes reflected in the genes that encode the microtubules.
The notothenioids also have a particularly interesting unique adaptation to low temperatures: their blood is full of "antifreeze" proteins. Proteins are chains of subunits called amino acids, with 20 different amino acids available to build up the chains. Proteins typically use most or all of the 20 different amino acids, but the "antifreeze" proteins consist only of 4 to 55 "repeats" of a chain of just three amino acids. Analysis shows that the genes for the antifreeze proteins seem to have been derived from a digestive enzyme (a protein that acts as a catalyst), with a chunk of the gene for the enzyme breaking off and being relocated on the fish genome. The clue is that the antifreeze gene includes a chunk of "noncoding" DNA that is also associated with the digestive enzyme.
Evolutionary theory envisions a branching tree of species flowing out from common ancestry, and the pattern of distribution of these various cold-water adaptations gives a strong clue to their history of emergence. The notothenioid species, with their antifreeze proteins and modified microtubules, are estimated from DNA rates of change to have emerged about 25 million years ago. Red cell counts gradually declined, and then the icefish lost the ability to make hemoglobin, which occurred maybe 8 million years ago. Since only a third of the icefish have lost the myoglobin gene, that change occurred more recently still, and in fact can be regarded as a trait that is still evolving. [TO BE CONTINUED]NEXT
* INFRASTRUCTURE -- THE POWER GRID (9): Town power substations sometimes link directly to a single user, like a power-hungry aluminum mill, but much more usually they distribute power over town electric distribution systems to households and so on. The local grid is, like the higher-level network, hierarchical, with "primary" distribution lines providing a backbone and "secondary" lines tapping power off that backbone and driving it to the residences. The primary lines may operate at anywhere from 2,400 to 25,000 volts, with a small number going up as high as 46,000 volts -- the voltage generally rising with the length of the primary line, and the voltages tending to be set higher in recent years. Secondary voltages are of course fixed to the 120 VAC used in North America and the 240 VAC used elsewhere.
The residential power grid is very noticeable due to the large number of power poles set up to carry the power lines. They are usually (but not always) made of wood, single logs of trees like cedar or Douglas fir, which grow tall and straight. The poles are treated with creosote or other preservatives to protect them from rot -- though they will rot eventually, usually at the ground line. Poles for relatively high voltage lines will be up to 27 meters (about 90 feet) tall, but most are more like 9 to 12 meters (30 to 40 feet) tall, with about 20% of that buried. Poles with heavy loads may feature guy wires.
Not too surprisingly, the highest-voltage lines are strung on the top of the pole, the "classic" arrangement being three conductors strung on a crossbar. However, there are plenty of variations -- three lines arranged vertically, strung on insulators attached to the pole, or on K-shaped or X-shaped arrangements of supports. There may be two or three sets of primary circuits on a pole, usually on multiple crossbars.
These days, the conductors are usually bare stranded aluminum, though some older lines have copper conductors -- usually rusted pale green. The insulators are generally mounted on top of a crossbar, not hanging down from them. Modern insulators are not so different from those on high-voltage lines, though they're not as long -- they don't handle really high voltages, so they can get away with being shorter. Older glass "pin"-type insulators are still around, however, featuring a "skirt"-style construction, sometimes with secondary skirts or "petticoats" underneath. An insulator has a groove in it into which a conductor is clamped.
The three conductors of a three-phase line are marked with colored tags, usually red, yellow, and blue. Residences usually just tap single-phase power from two lines so the color-coding is useless in that case, but it is important to know the arrangement of the lines for three-phase industrial motors and the like. Such motors will run backwards if they are wired up backwards.
* The comments about three conductors for three-phase power on a primary circuit are a bit misleading, since in practice there's generally a fourth conductor, strung further down the pole, usually with the secondary power lines. This is the "neutral" line, which provides a common voltage reference for all three phases. The neutral line is not used on the long-range high voltage lines since the three phases tend to be neatly balanced and the neutral voltage doesn't need to be pinned down. However, on end-user distribution systems, the loads on the different phases may be very different, resulting in an unbalanced line system. The neutral line allows one phase to be tapped off without any phase distortion from the unbalance. As a rule, it usually is so close to neutral that it doesn't carry much power, and so the insulators don't have to be very big.
There are variations in power-distribution system wiring. In North America, single phase AC is usually tapped off between a phase conductor and the neutral, while in Europe it's tapped off between two phase conductors. In addition, in North America three-phase power is usually only drawn off by industrial customers, but it's fairly common for European households to use three-phase for motors in dryers, air conditioners, and other big appliances. A three-phase motor is more expensive but more efficient.
In some rural or suburban areas, the primary circuit will consist only of a single conductor and neutral line. This is actually still three-phase power, sort of: it's just that different branches of the line use a different phase, reducing the cost of the distribution system. [TO BE CONTINUED]START | PREV | NEXT
* MACHINE TRANSLATION: Online language translation utilities like BabelFish are handy, but everyone knows they don't work very well. Languages are tricky and hard form computers to figure out. Now, according to a WIRED article ("Me Translate Pretty One Day" by Evan Ratliff, December 2006), a New York City business named Meaningful Machines may have a better idea.
Languages are ambiguous. The word "bank" in English might mean a financial institution, the edge of a river, or the turn of an aircraft. There's also the problem of context: the phrase "between a rock and a hard place" makes little sense on the face of it, but English speakers know it means "in a bind". Computer scientists have been working on machine translation (MT) since the early days, and they have had major problems getting it right.
The traditional approach was a "rule-based system", in which the rules of a language were written up in code, with an engine trying to interpret the rules to come up with a sensible translation. The problem is that the rules are complicated, often conflicting, and tend to be broken in practice on a regular basis by those who speak the language. In the late 1980s a group of researchers at IBM decided to try a different approach to MT, known as "parallel text", with particular effort focusing on a variant of that approach called "statistical-based MT".
The idea is conceptually simple: just obtain sets of proper translations, or "parallel corpora" as they are called in the trade, and then compile the statistical probability of a fragment of text in the source language mapping into a translation in the destination language. The statistical model obtained by this effort can then be used to perform new translations from the source language. By the turn of the century, statistical-based MT was pulling ahead of rule-based systems, and has been extending the lead dramatically since that time.
Every year, the US National Institute of Standards & Technology (NIST) assesses the effectiveness of MT systems using the "Bi-Lingual Evaluation Understudy (BLEU)" scale, which is used to rate translations from Chinese and Arabic to English. The top of the scale is 1, and a good human translator will come in from 0.7 to 0.85. In 2005, Google's stat-based system won the NIST evaluation for Chinese with a rating of 0.35 and for Arabic with a rating of 0.51. The Systran rule-based scheme, used by BabelFish, only rated 0.15 for Chinese and 0.11 for Arabic.
The problem with stat-based MT is that different types of writing end up having very different statistical patterns. A stat-based MT system that has been fed BBC World Service text will do well at more BBC World Service text, but it will fall down when handed a technical manual. The amount of parallel text needed to build a comprehensive stat-based MT system is horrendous.
That's where Meaningful Machines comes in: it's a stat-based MT system that doesn't use parallel text. The idea is to use a big collection of text in the target language, say English; a small amount of text in the source language, say Spanish; and a huge bilingual dictionary. The system pulls a chunk of text ranging from five to eight words long out of the Spanish text and produces all possible English translations, storing them in a dictionary. The scheme is called "flooding". Then the results in the dictionary are compared to the collection of English text to see which dictionary entries show up the most often. The gibberish translations are discarded, with the high-ranking translations judged likely to be the best fit.
To obtain the next chunk, the software moves only one word ahead, meaning that the words in the new chunk of Spanish text mostly overlap the words in the old chunk of text. The flooding procedure is repeated -- and so on and so on. A software system called the "decoder" then splices all the translations together, discarding those that don't dovetail.
The scheme is slick, but sometimes an unknown Spanish word will crop up. In such cases, a third subsystem, the "synonym generator" goes into operation. It hunts through the Spanish text to find the "mystery" word, and then focuses on the textual context of the mystery word, identifying translations that make sense when a plausible English word is plugged in place of the mystery Spanish word. Presumably, if that fails, the Spanish word is just plugged in to let the reader figure it out.
Meaningful Machines gets high BLEU scores with their prototype system, but the company doesn't have a production system yet, and the software they have is slow, too slow. Company engineers think it should be no problem to speed it up by an order of magnitude, however, and there's interest from US government agencies and the military. Whether Meaningful Machines ends up setting a new standard in MT or becomes yet another flash-in-the-pan startup that smashes itself up against a technical brick wall remains to be seen, but their concepts remain intriguing.BACK_TO_TOP
* PROXY WAR: The games of spammers and other cybercriminals often involve websites that come and go, as well as other tricks to making web traffic harder to trace and control. The irony is, as shown in an article in THE ECONOMIST ("Cat & Mouse, On The Web", 2 December 2006), such schemes are just as useful for civil libertarians as they are for cybercrooks.
Consider the website "Anonymouse.com", created in 1999 by Alexander Pircher, then a computer-science student in Darmstadt, Germany. Users can access Anonymouse.com and enter the URL of any website, which will be displayed by Anonymouse.com. This indirect access tends to be slow and doesn't work perfectly all the time, having some particular difficulties with video downloads, but it has a big shining virtue: users in countries where the authorities like to maintain censorship over the internet don't know what sites the users are accessing and so can't block them. Anonymouse.com gets three million visitors a day, and Pircher says he often gets thanks from users in Cuba, Iran, North Korea, and Saudi Arabia.
Anonymouse.com isn't the only "proxy" site on the web, with others joining in the fight against censorship. The flaw in the idea is obvious, however: the censors can just block the proxy sites. This leads to a war in which proxies jump from site to site -- much as the websites run by spammers to sell products dance around the web -- with various schemes, such as email lists, used to tell users where to find the latest incarnations of proxy sites. Even Chinese censors, regarded as the toughest, may not find a new proxy site for a week or, if it doesn't get much traffic, months. A Chinese activist calls the process the "game of cat and rat".
An American nonprofit group named "Tor" has a somewhat more sophisticated approach to the game. Supported by funds from the US Naval Research Laboratory and the "Electronic Frontier Foundation", a free-speech advocacy group, Tor wrote software that can be downloaded from many websites. The software will encrypt web traffic and select three proxy sites at random from a long list of those available to obtain the traffic. Not only are the censors unable to read the traffic, making it hard to determine its content, they also have no real idea where it's coming from, and the source changes all the time.
Another interesting scheme was developed by a Chinese human-rights activist named Huang Qi. He was locked up for five years; after he was released, he came up with a web browser named "Wujie" that will hunt the Web on its own for a proxy site.
Bill Xia, a Chinese activist living in North Carolina, operates on a different cyberfront. His company, Dynamic Internet Technology, is effectively a spam operation with support from the US government that emails millions of transcripts of VOICE OF AMERICA and RADIO FREE ASIA into China and Vietnam every day. Xia's tactics for getting the emails through firewalls are exactly those used by ordinary spammers: using synonyms for words likely to be flagged by defensive software, using unorthodox spellings for words, and interspersing characters with asterisks and the like. No doubt the rats are enjoying their game with the cats.BACK_TO_TOP
* COOL OFF: As reported by an article in THE ECONOMIST ("Plan B For Global Warming?", 10 March 2007), it's been generally accepted, at least by the science community, that human emissions of "greenhouse gases" are causing the Earth to warm up, and the general response has been to push for reductions in greenhouse gas emissions. However, a number of researchers have suggested whizzier ideas for dealing with the "hothouse Earth" problem.
Such notions are collectively known as "geo-engineering", and there's been considerable activity in the field recently, with series of papers published in scientific journals and conferences run on the topic. The most exotic scheme so far is the idea of placing a constellation of "sunshade" spacecraft at the Earth-Sun Lagrange point -- the location in space where the gravitational force of the Earth and Sun balance, where spacecraft can be kept on station with relatively little effort.
Roger Angel, an astronomer at the University of Arizona well known for his work on advanced telescopes, envisions each spacecraft as being about a meter across, with the total mass of the constellation running to about 20 million tonnes. The spacecraft would be shot into space using a magnetic launcher. They would have solar-powered ion thrusters to move them to the Lagrange point and keep them on station once they were in position. Angel estimates the cost of the scheme at a trillion dollars. He admits it would only be attractive if all other options failed.
Paul Crutzen, a Nobelist atmospheric chemist, wants to take a hint from nature. Volcanic eruptions can throw particulates into the upper atmosphere that cause a cooling effect; a similar effect from particulate air pollutants also caused a small degree of cooling some decades back that switched to warming once air pollution controls became widespread. Crutzen thinks that it might be possible to inject harmless aerosols into the upper atmosphere to obtain the same effect. Others have suggested the scheme might be used locally, for example to help preserve the polar icecaps.
John Latham of the US National Center for Atmospheric Research (NCAR) in Boulder, Colorado, has a simpler idea: spraying droplets of seawater into the air to generate low-lying, highly reflective oceanic clouds. The trick is to figure out an economical method to generate the sprays. Stephen Salter of the University of Edinburgh has an idea on how to do it: build a fleet of unmanned vessels that could generate the sprays using wind power. Each vessel would cost a few million and spray about 10 kilograms of seawater a second. 50 vessels could be able to cancel a year's carbon-dioxide emissions; additional fleets would be built each year until emissions were brought under control. Salter believes his scheme would be relatively economical and precise. Fleets could be dispatched to the North Atlantic in the summer to protect the Greenland ice sheets, and transfer to Antarctica six months later. He also suggests that the cooling clouds could be used to lower sea temperatures in tropical areas and help prevent hurricanes from forming.
Other ideas have included seeding the ocean with nutrients, for example iron, to encourage the growth of photosynthetic plankton that would soak up carbon dioxide; or to cover deserts with reflective sheets. Critics have been highly skeptical of such schemes -- one estimates that about half the world's deserts would need to be carpeted with reflective sheets to be effective -- and there are sensible worries that such "fixes" might well have unintended consequences.
There are Greens who oppose the whole notion of geo-engineering on the principle that it encourages people to believe that there is a quick technological fix to the problem of climate change, discouraging efforts to take real action. On the other side of the coin, advocates can point out that if matters go from bad to worse too rapidly, the technological fix might be the only thing available to save the planet from disaster.BACK_TO_TOP
* FAKE PRIESTS: The Japanese have their own way of doing things that can be interesting to outsiders. One, according to a BBC WORLD Online article, is the use of Westerners living in the country to pretend to be priests and conduct weddings.
Although only a few percent of Japanese are Christians, most of the weddings these days are Western-style -- a common scene in Japanese romantic pop fiction is a young woman looking through a shop window at a Western-style wedding dress and fantasizing about possibilities. Since there are so few Christians in Nippon, that means very few priests, but no problem: just hire a Westerner to dress up like a priest and perform the ceremony. Besides, most real priests in Japan are, not surprisingly, Japanese, and using a Westerner instead feels more authentic.
Chapels for such marriages can be found in somewhat unusual places, for example in shopping centers. It's all perfectly legal, because the ceremony has no legal standing anyway; the married couple has to establish the marriage with a local civil registrar. According to a Briton living in Japan named Mark Kelly who's into the business: "I was living in Sapporo, studying Japanese, and I needed the money. It's far better paid than teaching in a language school. Being a fake priest is big business in Japan -- I've done a TV commercial for one company. In Sapporo, there are five agencies employing about 20 fake priests. In a city like Tokyo, there must be hundreds."
Kelly says the job has its difficulties. Marriages can be surprisingly tense, with the groom in particular afflicted by last-minute apprehensions, and there are also tensions from in-laws. Brides are also often pregnant and will get sick on the way up the aisle on occasion. He also recalled a marriage where a very elderly and dotty old man was present and tried to attack him -- the old man apparently had a flashback to World War II -- but was easily restrained by his relatives. Sometimes the fake priests run into real Japanese priests, who for obvious reasons don't like the fakes.
Kelly shrugs, saying it's just a matter of image: "I give a good performance. I use an Apache wedding prayer in my ceremony. It works very well, although I had to take out the part about the bear god in the sky. If people are crying by the end of the wedding, I think I have done a good job." Incidentally, the "Apache wedding prayer" is a fake, too -- it was produced by scriptwriters for the 1950 Western movie BROKEN ARROW.
* WHODUNIT: For some reason I ended up surfing the web off and on for a few days on the Kennedy assassination. I'm not sure why I did, since it's a completely obnoxious topic, with conspiracy theorists telling mutually contradictory, sometimes preposterous, stories and calling skeptics names. Of course, the skeptics call them names back, so it can be regarded as a mutual amusement.
It's more than a bit stale now. Although there are suspicious aspects to the events that took place in Dallas, Texas, on 22 November 1963, after going on half a century of crying wolf, nobody has come up with any convincing trace of the wolf. All the often incompatible theories about a high-level conspiracy founder on the unbelievable notion that such a secret could be kept for so long in the face of massive scrutiny. It's one thing to say there's an elephant in the room; it's another to say it's invisible. It seems like the conspiracy theorists don't expect to be believed any more and it amounts to nothing more than badly-scripted theater.
In any case, by 2063 nobody will be around who remembers or cares about the assassination. The history books, for lack of any other story that hangs together, will say without equivocation that Lee Harvey Oswald shot JFK and the whole controversy will retreat to the domain of scholars researching the cultural eccentricities of Cold War America as a thesis topic. If so, they may find an article from that marvelous source of hard facts, THE ONION News, titled "President Shot 129 Times From 43 Different Angles" and seemingly dated 25 November 1963, to be interesting reading:
US President John F. Kennedy was assassinated Friday by operatives of the CIA, the Giancana crime syndicate, Fidel Castro, Vice President Lyndon Johnson, and the Teamsters Union as he rode through downtown Dallas in a motorcade. According to eyewitnesses, Kennedy's limousine had just entered Dealey Plaza when the president was struck 129 times in the head, chest, abdomen, arms, legs, hands, feet, back and face by gunfire. The shooting began at 12:30 PM and lasted until 12:43 PM CST. In all, 43 suspects have been taken into the custody of the Dallas police.
Preliminary reports indicate that hitmen for the Giancana crime syndicate fired from a nearby grassy knoll, CIA agents fired from an office building slightly off the parade route, Cuban nationals fired from an overpass overlooking Dealey Plaza, an elite hit squad working for Teamsters President Jimmy Hoffa fired from perches atop an oak tree, a "lone nut" fired from the Texas Book Depository, a shadow-government sharp-shooting team fired from behind a wooden fence, a consortium of jealous husbands fired from an estimated 13 sites on the sidewalk along the route, a hitman working for Johnson fired from a sewer grate over which the limousine passed, and Texas Governor John Connally lunged at the president from within the limousine itself, slitting the president's throat with a combat knife.
The mortally wounded president was sped to nearby Parkland Hospital, where doctors with ties to Johnson's inner circle performed a staged autopsy. They pronounced him dead at 2:18 PM CST. The body was then chemically treated by FBI Director J. Edgar Hoover and put in a decoy casket for transport to Roswell, New Mexico. There, space aliens performed an examination of the president's body, obtaining cell samples for cloning, before using a matter transporter to send it on to Washington DC.
Officers found several hundred weapons within a four-block radius of the shooting site, including telescope-sighted Weatherby Magnum rifles, Italian bolt-action 6.5 millimeter carbines, Thompson submachine guns, Russian Kalashnikov assault rifles, crossbows, machetes, ninja throwing stars, blowguns, spears, hatchets, bricks, and one ray-gun.
The assembled killers were taken into police custody at Dallas City Hall. As they were being transferred to the county prison two days later, all 43 were shot and killed by Jack Ruby, 52, a Dallas-area nightclub owner.
I've taken some liberties with the text. I found it posted on a conspiracy theory forum. The response to the posting was, and I am not making this up: "Cut the bullshit!"BACK_TO_TOP