jul 2009 / greg goebel
* This weblog provides an "online diary" to provide notes on current events, interesting items I run across, and the occasional musing. It promotes no particular ideology. For update notifications, follow "gvgoebel" on Twitter.
* THE PARASITES (9): While the malarial Plasmodium protozoan parasite is tricky, the Trichinella roundworm responsible for trichinosis has its own interesting bag of tricks -- first and foremost the matter that it is a multicellular worm that takes up residence inside a single host cell.
Trichinella eggs hatch in the intestines of the host organism, with the worm then drilling through the intestinal lining to access the bloodstream. It flows through the body and finally takes a branch into a fine capillary, where it finds a long, spindly muscle cell and penetrates it. At first, the muscle cell seems to atrophy, changing from wiry to smooth and disorderly; however, the roundworm is not so much wrecking the cell as just remodeling it into a home for the parasite.
Trichinella hijacks the muscle cell's DNA, and restructures the muscle cell by forcing it to produce collagen, the fibrous protein that makes up hair and nails, to encapsulate the cell. The parasite also makes the cell produce a signal molecule named "vascular endothelial growth factor", which directs the growth of blood vessels -- in this case to wrap a network of capillaries around the collagen capsule, allowing the parasite to draw nourishment from the host's blood.
Incidentally, we are not Trichinella's its normal hosts. The problem, from the roundworm's point of view, is that its host has to be eaten by another mammal to pass the parasite along. Humans are only infrequently prey of other animals, and we bury or burn our dead so that the corpses will not become meals for dogs. Trichinosis is also one of the reasons that human cannibalism, besides being reprehensible, tends to be an unhealthy diet.
* As mentioned in an earlier installment, roundworms are serious plant parasites; roundworms that live in plant roots are estimated to destroy 12% of the world's crops each year. One particular genus of "root-knot nematodes" named Meloidogyne has behavior that mirrors its Trichnella relative, but adapted to parasitize plants.
A Meloidogyne roundworm hatches in the soil and crawls around to find the tip of a root. The roundworm uses a spike in its mouth to stab into the root, with the parasite's saliva causing the surface cells to burst, allowing the roundworm to creep inside the root. It drives its way in until it reaches the core of the root, where it stabs several cells, injecting chemicals into them to hijack their cellular systems.
Normally, the cells in the root of a plant draw in water and nutrients from the soil, to then pump them through the circulatory system of the plant. Under the influence of the roundworm, however, the cells start drawing water and nutrients from the plant, with the parasite then drawing in turn from the accumulation. However, the swelling of the cells may threaten to burst the root open, which will destroy the roundworm's happy home. It has no worries along that line, however, since it makes surrounding cells multiply to form a sturdy protective knot around the root -- which is why it is known as a "root-knot" nematode. [TO BE CONTINUED]
* GIMMICKS & GADGETS: THE ECONOMIST had an article on a new approach to tooth root canals. Anyone who's ever had one knows they're no fun, and they also sometimes have to be repeated since it's hard to completely wipe out the bacteria in the tooth root. Researchers at the University of Southern California in Los Angeles (USC, not the same place as UCLA), have come with a better way to kill them off: use a dental plasma torch.
"Say wot?" Since plasmas are usually thought of as generated by high temperatures, on the face of it that sounds like an appalling idea. However, "cold plasmas" can be generated by electrical fields, as shown by the "flames" known as "Saint Elmo's fire" that appear on the masts of ships in electrical storms. The USC researchers came up with a prototype plasma dental tool and found it could clean up infected teeth neatly; the ionized oxygen atoms, obtained from air, in the cold plasma were particularly effective in destroying bacteria. The same technology may also be applicable to infected wounds.
* WIRED Online's blogs have been providing the usual stream of interesting gimmicks, of varying levels of credibility:
A number of firms have come up with a solution: put the speakers on the HDTV display itself. The idea is to place a sheet of transparent polyethylene terepthelate (PET) plastic on the display with piezoelectric actuators on the sides that press in and out on the sheet to make it vibrate in and out. It appears that the "edge motion speaker" scheme works very effectively, though it cuts display brightness by an increment and is more expensive than old-fashioned electromagnetic speakers.
The idea behind the Cube is basically to create a vehicle that isn't much heavier than the passenger and useful for short-range trips. It's just a concept, no hardware, digital mockup only. I don't know if it's brilliant or crazy. It would feel like riding R2-D2 around town.
One of the more intriguing gimmicks from the WIRED blogs was from a US firm named KCI Communications, which has introduced a "Smart Black Box (SBB)", sort of like an airliner flight recorder for cars. It's tacked up to the top of the windshield and takes continuous video through a fisheye lens, logging the car's current GPS coordinates, speed, direction. It also includes a shock sensor that "freezes" that, when an impact is registered, "freezes" the 15 seconds before and 5 seconds after the impact in the device's SD card flash memory. The SBB costs about $300 USD, which is not bad for its capabilities. It may not occur to everyone that they actually need the thing, but KCI officials suggest it could be useful for beating the rap on a speeding bust -- and that it might become very popular if insurance companies start offering a discount to drivers who use it.
The biggest problem with the SBB as far as I can see is the fact that it's a relatively spendy item that a thief can see immediately and so could lead to a fair number of busted windshields. I suppose that it could be easily popped out and pocketed for security; another option would be to assign a serial to each unit, which isn't so hard to do this days, meaning anyone who tried to use a stolen unit to present a case to the law would run the risk of being busted.
It might also be interesting to have an SBB with a WiFi interface one of these years, allowing it to be tracked by an urban WiFi network. Of course the user would have a "track / no-track" option to ensure privacy when it's desired. On considering that idea, it seems that somewhat stumbling efforts of municipalities to set up city WiFi networks have, if the startup problems can be addressed, an even bigger potential payoff once the use of automotive WiFi is factored in.
* ANOTHER MONTH: BBC WORLD Online ran an interesting little article on a behavioral study performed in the UK in which students were asked about their attitudes toward receiving an organ transplant from a criminal. A good proportion of the students were averse to the idea of obtaining the heart of a murderer. Along the same lines, about one in three organ donor recipients claim they have had personality changes that they attribute to the influence of the personality of the original donor.
Reality imitates bad horror movies. And yet ... I sympathize, we seem to have a natural inclination towards superstition. It appears as though along with the capability for logical thought, we necessarily acquired the ability to construct logic on false premises and fantastical connections. I find it amusing when, as I often do, I notice superstitious influences on my own behavior.
* There was a "hot rod" show over at the local county fairgrounds this last month. I like cars but I'm not really hot on them, and much prefer honest classic cars to "funny cars" -- too toyish in style for my taste. However, even though the admission was the better part of twenty bucks, I'd been pretty much a homebody all year long, so on the chance there were some classics out there I went on a brief camera trip.
I paid my money and did a quick sweep of the fairgrounds. It was worth my time, there were many pretty cars, all of which were so neatly made up that the idea of laying a finger on them made me cringe. Classic rock tunes were played over the PA system, which seemed to fit the ambience perfectly. I was particularly impressed with a yellow 1934 Dodge convertible brought up to a peak of modernization, without compromising its traditional appearance. The upholstery was new, the rumble seat probably looked better than it did when the thing came off the showroom floor.
There was a fellow sitting nearby, and I asked him: "This yours?"
"Yeah."
"It's sweet".
"Thanks." I was about to leave but suddenly had a hunch and stuck my head over the car door to check out the dashboard. My hunch was right, and I said: "I just KNEW you had to have an iPod in this thing!" He laughed.
* The mix of technology from different eras in that car reminded me a bit of the BATMAN ADVENTURES animated series of the 1990s. One of the interesting features of the series was that it had a 1940s ambience, using car and clothing designs from the decade plus a fair amount of Art Deco design, but they stealthily spliced modern technology in with it. They'd have a postwar-era car run into a telephone pole and pop out airbags; or show Bruce Wayne watching a football game played with 1940s-style football helmets, and checking a replay on the VCR.
The BATMAN ADVENTURES series was actually much better scripted and more imaginative than any of the BATMAN Hollywood blockbusters, though that's not much of a claim. I liked the Joker: "Harry, you welshed on a bet with me, and I hate welshers -- so I broke out of Arkham Asylum, and now I'm going to give you a vicious beating with this bunch of bananas!"
"Joker, you're crazy!"
"Oh, I KNOW! I've got a CERTIFICATE and EVERYTHING!"
