Thursday, March 27, 2008

Knee Power

A new human-powered generator tries to capture walking energy.

Power walking: This knee brace (above) sports a generative-braking power system that converts energy expended while a person is walking into electricity.
Credit: Greg Ehlers, Simon Fraser University
See the knee brace in action.

Engineers who design wearable devices that harvest human energy for power face a daunting dilemma: how do you collect a significant amount of power without making the user expend a lot of extra effort? Gadgets like hand-crank generators and windup radios require manual work from a user, and existing shoe-mounted generators produce less than one watt of power.

A team of engineers has developed a modified knee brace that captures energy that would otherwise have been lost while the wearer walks. The generator produces about five watts--enough to power 10 cell phones simultaneously.

"If you want power, go where the muscles are," says Max Donelan, a professor at Simon Fraser University, in British Columbia, who led the research. "We thought, maybe there's a smart, selective way to do energy harvesting when muscles are normally decelerating in the body." Donelan's research appears in the February 8 issue of the journal Science.

Donelan looked to the legs, which have the largest muscles in the body, and capitalized on a careful understanding of how humans use energy to walk. During an average stride, a person uses her muscles to bend at the knee and swing her leg forward, like a pendulum bob. This is positive work. At the end of the swing, she executes negative work to decelerate her moving leg. She places her foot on the ground, and by then her other leg has begun its swing.

Donelan and his team concentrated on harvesting energy from the end of the stride using their bionic knee brace. When the brace's generator is engaged, it collects power while slowing down the motion of the leg. As a result, the brace reduces the human effort required at the end of the swing phase.

If the mechanism were continuously engaged, however, it would also impede acceleration at the beginning of the swing and require more energy from the wearer. To solve this problem, Donelan installed a sensor in the device to monitor the knee angle and switch the generator on and off. According to his research, this "generative braking" approach requires only one-eighth the metabolic power of a continuously operating mechanism.

"What's extremely clever about this device is that it only tries to capture mechanical energy when the muscles would be primed to slow the body down," says Lawrence Rome, a biology professor at the University of Pennsylvania. Rome, who did not work on the knee brace, recently designed a backpack that converts walking energy into electricity. "[Donelan's knee brace is] a smart device, and it only works when you're trying to brake yourself," says Rome. "It lets the reverse torque of the generator do the work of the muscle."

Finding Energy All Around Us

You won't feel comfortable or fashionable walking around with Max Donelan's invention strapped to your knee. The bulky 3.5-lb. (1.6 kg) gadget "is not that pleasant," says Arthur Kuo, a biomedical engineer at the University of Michigan, who co-wrote an article on the brace that appeared in Science last month. But Donelan's device pays off in other ways. Using the same principles that allow hybrid cars to recycle energy created in braking, braces worn on both knees can generate 5 watts of electricity by harvesting the energy inherent in a walker's stride. That may not sound like much, but it's enough to charge 10 cell phones, and it's absolutely free. "People like the idea of generating their own power," says Donelan, a kinesiologist at Simon Fraser University in British Columbia. "If you do things in a clever way, you can get energy cheaply."

Getting energy cheaply has never been more necessary than it is now, with oil recently breaking its all-time inflation-adjusted high price. The era of inexpensive power is over, perhaps for good, which means it's time to extend beyond energy efficiency to energy-scavenging, harnessing the sort of wasted watts we wouldn't have bothered with in the past. Fortunately, scientists are finding new ways to harvest unused energy from the environment, industrial activities and even the heat and motion of our bodies. "Energy-scavenging has been around for years, but because of the fuel crisis, everyone from big companies to small ones is looking to utilize it," says Marc Poulshock, president of Thermo Life, which produces devices that can harness thermoelectric energy. "It's a very hot topic."

One of the most abundant forms of unused energy in the environment is the vibrations that are a by-product of motion. Think of the rumblings of a bridge in heavy traffic or even the pulse of a dance floor. That's essentially free movement, and scientists can transform that micromotion into electricity in a number of ways. One should be familiar from high school physics class. A magnet hooked up to be sensitive to vibrations wobbles inside a copper coil, generating a current through electromagnetism. Steve Beeby, an engineer at the University of Southampton in Britain, created a vibration harvester that works on that principle much more efficiently than similar devices did in the past. The electricity isn't much: his devices now generate hundreds of microwatts at most, and there may be an upper limit to how much energy can really be scavenged from vibrations. "It's very unlikely on a big scale," says Beeby, who directed the European Union's Vibration Energy Scavenging project. "It will never compete with wind power or anything like that.",9171,1720111,00.html

Gene Therapy for Chronic Pain

Researchers use gene therapy to stop pain signals before they reach the brain.

The pain gate: When we suffer pain--whether from a stubbed toe or a metastasized tumor--pain signals are transmitted to the brain from around the body through these groups of sensory neurons, called dorsal root ganglia (DRG). A new gene-therapy technique intercepts pain signals at the DRG using a gene for a naturally produced opiate-like chemical. On the right, the cells of a rat's DRG glow green with a marker for the opiate-like gene one month after it was injected into the rat's spinal fluid. On the left are DRG cells from a control rat injected with saline solution.
Credit: PNAS

A new kind of gene therapy could bring relief to patients suffering from chronic pain while bypassing many of the debilitating side effects associated with traditional painkillers.

Researchers at Mount Sinai School of Medicine injected a virus carrying the gene for an endogenous opioid--a chemical naturally produced by the body that has the same effect as opiate painkillers such as morphine--directly into the spinal fluid of rats. The injections were targeted to regions of the spinal cord called the dorsal root ganglia, which act as a "pain gate" by intercepting pain signals from the body on their way to the brain. "You can stop pain transmission at the spinal level so that pain impulses never reach the brain," says project leader Andreas Beutler, an assistant professor of hematology and medical oncology at Mount Sinai.

The injection technique is equivalent to a spinal tap, a routine procedure that can be performed quickly at a patient's bedside without general anesthesia.

Because it targets the spinal cord directly, this technique limits the opiate-like substance, and hence any side effects, to a contained area. Normally, when opiate drugs are administered orally or by injection, their effects are spread throughout the body and brain, where they cause unwanted side effects such as constipation, nausea, sedation, and decreased mental acuity.

Side effects are a major hurdle in treating chronic pain, which costs the United States around $100 billion annually in treatment and lost wages. While opiate drugs can be very effective, the doses required to successfully control pain are often too high for the patient to tolerate.

"The side effects can be as bad as the pain," says Doris Cope, director of the University of Pittsburgh Medical Center's Pain Medicine Program. Achieving the benefits of opiate treatment without their accompanying side effects, Cope says, would be a "huge step forward."

Beutler hopes to do just that. "Our strategy was to harness the strength of opioids but target it to the pain gate, and thereby create pain relief without the side effects that you always get when you have systemic distribution of opioids," he says.

Several groups have previously attempted to administer gene therapy for pain through spinal injections, but they failed to achieve powerful, long-lasting pain relief. The new technique produced results that lasted as long as three months from a single injection, and unpublished follow-up studies suggest that the effect could persist for a year or more.

Beutler credits his team's success to the development of an improved virus for delivering the gene. The team uses a specially adapted version of adeno-associated virus, or AAV--a tiny virus whose genome is an unpaired strand of DNA. All the virus's own genes are removed, and the human endogenous opioid gene is inserted in their place. Beutler's team also mixed and matched components from various naturally occurring AAV strains and modified the genome into a double-stranded form. These tweaks likely allow the virus to infect nerve cells more easily and stick around longer.

What HDTV technology is right for me?

You've decided that HDTV is for you and you're ready to hit the high street. You've heard about LCD, Plasma, and Rear Projection, but what are the differences? what are the pros and cons of each technology? and which one is right for me?

Plasma TVs

Plasma TV’s screens are perfectly flat. They produce natural, vibrant colours while maintaining a very high level of detail. Pixels on a Plasma screen are ‘lit’ at once, unlike normal TVs, where the image is scanned across the screen. The image is therefore sharper and brighter.

This is great for regular room lighting and can be watched from most distances and angles without affecting your viewing experience. Even as you get closer to the screen, you will not be affected by changes in picture or colour quality. They are only a few inches thin which provides a lot of options when it comes to installation.

In addition to stand mounting, they can be hung on a wall or from a ceiling. All plasma TVs are designed in widescreen.

Plasma displays do not use electron beams, as conventional TV displays do. They are therefore immune to the effects of magnetic fields. This allows for speakers to be placed quite close and will not compromise your home cinema set up.

Main advantages of Plasma over LCD are:

Larger screen size availability – Plasma screens range from 37" up to 60" (although the choice of LCD TV's up to 50in is growing rapidly).
Better contrast ratio and ability to render deeper blacks.
Better colour accuracy and saturation.
Better motion tracking (little or no motion lag in fast moving images).

Main disadvantages of Plasma over LCD include:

Plasma TVs are more susceptible to burn-in of static images.
Plasma TVs generate more heat than LCDs, due to the need to light of phosphors to create images, and consequently use considerably more power.
Does not perform as well at higher attitude.


LCD stands for Liquid Crystal Display. This means that the screen is made up of millions of tiny liquid crystal molecules, called pixels. These function like a camera shutter, allowing light to either pass through or be blocked as voltage is individually applied so they change state to create an 'image'. The colour is added to the LCD display through three filters (red, green, and blue) that are applied to each pixel. LCD TV screens always maintain sharp, clear pictures without reflection from artificial lights or bright sunlight through windows.

LCD technology is extremely lightweight therefore products are both highly portable and versatile. With screen sizes ranging from 13" (4:3) to 40"+ widescreen, this means you can watch LCD TV wherever you want!

This means flicker-free images for a more comfortable viewing experience with less eyestrain, even when viewing close-up. Also, since no static electricity is generated on a LCD screen it remains virtually dust free and clean for perfect viewing all the time.

Main LCD television advantages over plasma include:

No burn-in of static images.
Cooler running temperature.
No high altitude use issues.
Increased image brightness over plasma.

Main disadvantages of LCD vs. Plasma televisions include:

Lower contrast ratio, not as good rendering deep blacks.
Not as good at tracking motion.

Plasma TV vs LCD TV

Despite assurances by manufacturers that the technology has improved, consumers are still complaining of ghost images on their screens after displaying still images

Jamie bought his Pioneer plasma television in January and, after playing Guitar Hero 2 on his Xbox 360, noticed faint residue images of the game's score meters on his screen. He was told that leaving the TV on overnight on a static channel with no transmission would solve the problem.

"This has reduced the screen burn slightly but I can still see it, especially when a light image is on the area of burn," he wrote on the message board in June. "Does anyone have any other ideas on getting rid of the burn or am I stuck with it?" he asked.

So far, only one respondent has given Jamie any advice — he should try the pixel shift or "other fancy things" on his television, replied a poster known as "me."

Jamie's problem, known as plasma burn or more technically as "image retention," is considered rare by television manufacturers, with some even labelling it a myth. But if Jamie's and numerous other posts on various technology forums are any indication, the issue is real and contributing to a general mistrust of plasma televisions.

"Here I am stuck in a rut where the only the thing [the] owners manuel [sic] says about screen burn-in is that it's not covered under your three-year warranty," wrote Joey M of his new Dell plasma television on the message board earlier this year. "All I can say is that I hope the pixels [completely] go out before my three-year warranty is up so I can exchange it and start over. Please, don't do what I did."

"There is no such thing, almost, as burn. You have to as an end user almost intentionally try … very hard to burn a set."

— Barry Murray, director of marketing for the audio-visual group at Panasonic Canada Inc.

Team Xbox, a website devoted to Xbox games run by entertainment and video games site IGN, says the problem extends beyond video games.

"Plasma televisions, despite being sexy as hell, are highly susceptible to burn-in from static images, including station identification tags that you see on TV broadcasts and [heads-up display] images like those found in most video games," writes editor Rob Semsey on the site's discussion forums. "There's no doubt that it stings after you've dropped anywhere from $2,999 [US] to $19,999 [US] on a new plasma HDTV, only to notice burn-in after marathon sessions of Madden NFL 06 or any other game."

The instruction manuals for the televisions themselves warn of the problem.

"Do not display a still picture for a long time," reads the manual for the Panasonic Viera, which lists channel numbers, logos and video games as typical examples.

Issue overblown, say manufacturers

The manufacturers, however, say the issue has been overblown and is often misunderstood. In a plasma television, static electricity heats the phosphors in the screen, which then produce the lights that make the picture. Ghost images on plasma televisions appear when those phosphors are used unevenly, such as when they are heated continually by displaying a still image.

Panasonic, which is the plasma screen market leader, says the term "burn" is a misnomer because the image is not actually burned into the screen.

"There is no such thing, almost, as burn. You have to as an end user almost intentionally try … very hard to burn a set," says Barry Murray, director of marketing at the audio-visual group at Panasonic Canada Inc.

Short-term image retention can happen, Murray says, but it usually goes away after watching a few minutes of full-screen video.

"It's fairly common but 100 per cent reversible just by watching other video programs."

Today's plasma screens have numerous technologies built into them to prevent permanent image retention, Murray says, including "pixel wobble," which detects static images such as station logos and moves them subtly in a way that is imperceptible to the eye and prevents overuse of the same pixels.

Many televisions also have a "whitewash" function, which blankets the screen in a static white image that resets the static charge in all of the pixels.

Phil Joly, central territory manager for Samsung Canada, says the most important way to avoid plasma image retention is to set up the television properly. Most sets seen on store floors are set to "vivid" modes with high brightness and contrast, which is not how they should be viewed at home.

"If your TV gets set properly once it's in the house and has its contrast toned to say 75 per cent or even 65 per cent, the possibility for burn in for something like that drops by as much as 80 per cent," he says. "The biggest mistake the consumer can make is not setting up the plasma properly."

Consumers who do suffer image retention that doesn't go away quickly can try buying a whitewash DVD, if their set does not have the function built in. They can also try setting their television to a static channel overnight, as Jamie on the Gadgetopia message board did.

Still, some consumers — such as Joey M on Ecoustics — are upset that even after enacting preventive measures and possible cures, their sets aren't covered for image retention issues under warranty.

Panasonic's Murray says this is because the onus is on consumers to watch how they use their television.

"If somebody overtly abuses their set or uses it in a wrong application — one that we don’t recommend — that's why it's not covered under warranty," he says. "If somebody came to us and said, 'Look I have an issue here, I can't get rid of this,' we do have 48-hour in-home service on those things under the warranty period. Even outside of the warranty period, chances are we would look after the customer."

Ideal for gaming

Still, Murray says plasma televisions are ideal for video gaming because they present much deeper colours than rival LCD screens. LCDs are slower than plasmas, which means they can get blurry when displaying fast-moving images.

Samsung's Joly admits that LCD screens are slower than plasma, but they are catching up. LCD technology is also proving to be the choice of gamers because of the threat of plasma burn, he says.

"Gamers are pretty well educated, so most of them will go with LCD because there's still that primal fear of burn-in that's out there."

LG Electronics, one of the top sellers of both television technologies, says the motion blur on LCD screens has improved to where it almost imperceptible by the human eye.

"Most people can't detect it," says Frank Lee, manager of public affairs for LG Electronics Canada.

LCD televisions, however, are themselves not immune to burn in, but this is "even more rare" than with plasma, according to consumer electronics website

In any event, consumers in general are increasingly opting for LCD over plasma, according to statistics from NPD Group, which tracks trends in electronics. Both types of screens are growing rapidly, but over the past year LCD televisions have accounted for 61 per cent of flat-panel sales in Canada, versus 39 per cent for plasma.

Prices on flat panels have come down 30 per cent in the past year and the cost of plasma and LCD sets between 40 and 44 inches, the most popular sizes, are now almost identical, NPD says.

In the end, LG's Lee says plasma is better for watching movies in a home-theatre environment while LCD screens are generally more versatile.

"LCD is really the way to go for gaming," he says.

Plasma TV: Tips

Plasma TVs are expensive pieces of technology that deserve great care from you. Treat it well, and the wad of cash you spent on your plasma display will go a long way; treat it bad, and count your dough as money spent unwisely. Here are some tips to help you lengthen your plasma television’s lifespan.

  • Don’t set the contrast to a high level. Keep it as low as possible!
  • Related to the previous tip, if possible do your TV viewing in a dimmer room. Here, a lower contrast setting for your plasma TV will be perfectly fine.
  • Read the instructions manual for your plasma display carefully. Each unit from different manufacturers can differ in specifications, so reading up on those papers will be worth it.
  • It’s not advisable to leave still images on the plasma display as they can cause burn in.
  • Keep your plasma TV free of dust.
  • As with every glass product, TV, and monitor, take care when handling or transporting your plasma display panel. That sleek thing is fragile, you know.
  • Remember that the plasma television is an electronic device. Keep water away from it, at all costs. You don’t want to fry both yourself and the TV, right?
  • Because water is a no-no, just use anti-static cleanser and cloth when cleaning your plasma display’s screen. Static electricity is a definite enemy of the plasma unit.
  • When mounting a plasma TV on a wall, don’t do it alone – ask for the help of a second person. Just make sure your wall anchors are level with each other, and securely attached.
  • Use a surge protector with your plasma television. There’s no use skimping on one if your TV gets fried by electrical storms.

HD ready 1080p

n order to be awarded the label "HD ready 1080p" (not equivalent to Full HD) or the older "HD Ready" logo a display device has to cover the following requirements:

HD Ready 1080p (encompasses Full HD) HD Ready
Minimum native resolution 1920x1080 720 horizontal lines in widescreen ratio
Accepted video formats are reproduced without distortion Yes No
Display 1080p and 1080i video without overscan (1:1 pixel mapping) Yes No
Display native video modes at the same, or higher, refresh rate. Yes No
Analogue YPbPr HD input Yes Yes
Digital HDMI or DVI HD input Yes Yes
720p HD progressive (1280x720 @50 & 60 Hz) Yes Yes
1080i HD (1920x1080 interlaced @50 & 60 Hz) Yes Yes
1080p HD (1920x1080 progressive @24, 50 & 60 Hz) Yes No
The HDMI or DVI input supports copy protection (HDCP) Yes Yes

Older products that bear the label "HD ready" may not display the full picture resolution possible from an HD source. Most HD-ready sets do not have enough pixels to give true pixel-for-pixel representation without interpolation of the higher HD resolution (1920x1080) - or (in rare cases) even the lower HD resolution (1280x720) horizontally (CRT based sets, or the plasma-based sets with 1024x768 resolution). This limitation has been removed in the "HD Ready 1080p" logo

The term HD compatible is also being used in Europe to indicate that a display device has HDMI capability but with lower than HD-ready resolution.

The following technical references apply to the above descriptions:

DVI: DDWG, “Digital Visual Interface”, rev 1.0, Apr 2, 1999 as further qualified in EIA861B, “A DTV Profile for Uncompressed High Speed Digital Interfaces” May 2002, furthermore allowing both DVI-D and DVI-I connectors, requiring compliance to both 50 and 60 Hz profiles, and requiring support for both 720p and 1080i video formats.

HDMI: HDMI Licensing, LLC, “High-Definition Multimedia Interface”, rev.1.1, May 20, 2004

HDCP: Intel, “High-Bandwidth Digital Content Protection System”, rev 1.1, June 9, 2003.

(NB: on DVI HDCP rev 1.0 will apply)

YPbPr: EIA770.3-A, March 2000, with the notice that the connectors required may be available only through an adaptor.

HD ready

HD ready concerns the abilities of television receivers to display high-definition pictures. The term has had official use in Europe since January 2005 when, EICTA (European Information, Communications and Consumer Electronics Technology Industry Associations) announced the requirements for the label.

EICTA introduced the label as a quality sign for the differentiation of display equipment, capable of processing and displaying high-definition signals. It is awarded on the basis of minimum functionality requirements that are detailed in the "EICTA conditions for HD Labeling of Display Devices".

In the USA, "HD Ready" refers to any display that is capable of accepting and displaying a high-definition signal at either 720p, 1080i or 1080p using a component video or digital input, and does not have a built-in HD-capable tuner.

Alternatives to HD ready TVs

Many PCs and laptops are actually more HD ready, in the true sense of the phrase, than the HD ready label requires. They will not, however, qualify for the HD ready label, unless they also meet the connector requirements.

Any sufficiently fast computer with a 1280x720 or higher resolution display is capable of displaying HD video, even though computers are generally not advertised as such. This video may come from the Internet, data files, or a DTV tuner card. The Internet already offers some HD content, like movie and videogame trailers.

HDTV programming compared

Antenna vs. cable vs. satellite


With MPEG-4 receivers, satellite offers significantly more national HD channels than cable; HD DVRs typically superior to cable.
Monthly fees; still need over-the-air antennas to get some local channels, such as PBS HD and MyTV; may not offer RSNs in HD; usually requires purchase of set-top box.
With MPEG-4 compression making numerous HD channels a reality, satellite is the best way to get the most HD programming.

MPEG-4 technology allows satellite providers to offer more HD channels than most cable services.
For the past few years, HD via satellite has been a promising yet frustrating way to get high-definition shows. By subscribing to DirecTV or Dish Network, viewers living in the most far-flung areas of the continental United States--and those who'd rather not pay for cable--could get their fair share of HD. However, because bandwidth is at a premium and because each satellite must broadcast the literally hundreds of local channels separately, DirecTV and Dish Network initially stumbled when it came to offering local HD stations--that is, the major network affiliates of ABC, NBC, Fox, and NBC, that carry your local news and commercials.

Until recently, the only way to get high-definition local channels through your satellite receiver was with an over-the-air antenna add-on. To help compensate, satellite providers have offered a handful of national HD channels, such as the East and West Coast feeds of NBC, ABC, Fox, and CBS, but they don't have local news and ads, and they're legally available only in certain metropolitan areas and in rural areas that fall outside the broadcast range of terrestrial digital TV transmitters.

Satellite HD: A sea change

All of that has changed with the arrival of MPEG-4 AVC, a video compression technology that crams more than twice as much HD video into the same amount of bandwidth as the current MPEG-2 technology. Combine MPEG-4 with the deployment of new satellites--DirecTV launched the first of five new satellites in May 2005 and has one more slated for March 2008, while Dish Network launched another satellite in February 2006 and plans to launch "at least two more" in 2008 according to CEO Charlie Ergen--and suddenly there's much more bandwidth in the skies.

With big changes like MPEG-4 come big sacrifices. Older DirecTV and Dish Network dishes and set-top boxes aren't compatible with MPEG-4 services. DirecTV and Dish Network plan to broadcast the existing MPEG-2 HD lineup; for the time being, but subscribers with older HD equipment will have to upgrade to watch the new local and national HD channels. Luckily, both satellite carriers offer discounts to make the transition less painful.


DirecTV: To get DirecTV's MPEG-4 channels, you'll need an H20 or H21 HD receiver, or an HR20 or HR21 high-definition DVR, as well as a dish that can receive signals from five different orbital positions (typically free with a new installation). FYI, the 20 and 21 models of both receivers are basically identical save for coloration and the 20s' capability to connect to an antenna to get over-the-air ATSC broadcasts.

Dish Network ViP722 HD DVR
Dish Network: For Dish Network MPEG-4 HD service, you'll need an MPEG-4-compatible satellite dish and a receiver or DVR. Dish offers numerous solutions, starting with the basic ViP211 HD receiver and the ViP612 HD DVR. The company also makes three units--the ViP222 receiver and ViP622 and ViP722 DVRs--that can feed two TVs simultaneously, one standard-definition and one high-definition.


The arrival of MPEG-4 means big changes for the amount of local HD programming available from DirecTV and Dish Network. As of February 2008, DirecTV offers local HD programming to 77 U.S. cities, covering 74 percent of all U.S. households. Dish Network's local coverage currently lags behind DirecTV with just over 50 percent of U.S. markets, although the company promises 100 local markets and 85 percent coverage by year's end.

One important issue to keep in mind, however, is that neither DirecTV nor Dish Network broadcast all local channels in HD. Dish Network offers the top four networks (ABC, CBS, Fox, and NBC), and DirecTV offers the top four networks plus MyTV and PBS (but only in some markets). Meanwhile regional sports networks in HD aren't necessarily offered on satellite, whereas most cable providers offer RSNs in their local markets. See the cable section for details.

While HD local channel selection is generally better on cable than satellite, DirecTV and Dish Network each offer significantly more national HD channels than just about every cable provider. Excluding RSNs and pay-per-view channels, as of March 2008 DirecTV offers 59 national HD channels and Dish Network has 47.

Voom's HD channels are now available on Dish Network.
Voom's HD channels are now available on Dish Network.
We break down those channel lineups in-depth later in the guide, but for now a couple of things are worth noting. Dish's channel selection includes 15 all-HD channels that once were operated by the Voom. While "all-HD" sounds pretty great, bear in mind that none of these channels offer typical programming (for better or for worse) and they all repeat shows much more frequently than typical channels. However, some lesser-known gems can be found on the movie channels, and some offbeat shows on the specialty networks are watchable. But don't expect tier-one programming in most cases on these channels.

DirecTV, on the other hand, is the only place for the HD versions of favorite networks such as Bravo, CNN, Comedy Central, FX, and SciFi. Sure, most of these channels don't show HD all the time, but more often than not popular shows will be in high-definition. That's a huge advantage, and while we suspect Dish will try to catch up by offering these channels sometime in the future, they haven't done so yet.

Science, Medicine, Technology

Skeleton key

We knew our bones were busy producing blood cells and platelets, storing and releasing calcium into the bloodstream, and protecting our squishy innards. Now Columbia scientists have discovered an entirely new function of the skeleton: They say it also acts as an endocrine organ, producing a hormone that helps us process sugar.

Hormones, which control everything from growth to metabolism to reproduction, typically come from our glands or sex organs; a few have been traced to the heart, abdominal organs, and skin. They weren’t known to come from bone, until now. A research team led by Gerard Karsenty, chair of the Department of Genetics and Development at Columbia’s College of Physicians and Surgeons, has found that osteocalcin, a hormone released by bone cells, directly regulates the metabolism of glucose in mice. Shortages of osteocalcin, the researchers say, seem to cause obesity and type 2 diabetes in the animals.

There is “no guarantee” that the hormone behaves similarly in humans, “but osteocalcin exists in humans,” Karsenty says. “It operates in a region where type 2 diabetes genes are known to be present, and its levels vary with sugar metabolism, so we are cautiously optimistic.”

In mice, at least, osteocalcin controls blood sugar by increasing the proliferation of insulin-producing beta cells in the pancreas, signaling those beta cells to produce more insulin and triggering fat cells to release another hormone, called adiponectin, that enhances insulin sensitivity. Mice and men both rely on insulin to sweep sugar from the blood and into cells, where it is used as energy or stored as fat.

If osteocalcin has comparable effects on people, Karsenty says, its discovery could lead to a cure for the 20 million Americans with diabetes, in whom insufficient insulin levels can chronically elevate blood glucose, heightening the risk of heart disease, kidney failure, and blindness.

But the discovery that the skeleton interacts with other organs is stunning in itself, prompting scientists to reconsider the skeleton’s purpose. “It certainly has caused quite a stir,” Graham Williams, an endocrinology expert at Imperial College London, told the Web site Nature News recently. “People think it’s a novel idea, and likely to turn out to be a paradigm shift.”

Karsenty and his team had been searching for a skeletal hormone that communicates with fat since demonstrating in 2002 that leptin, a hormone produced by fat cells, is crucial to regulating bone mass. Given that most bodily systems work as feedback loops, if fat signals bone, it stood to reason that bone might also signal fat. Osteocalcin, already known to be lower in diabetics thanks to earlier studies investigating the link between diabetes and an increased incidence of bone fractures, was thrown into the mix of suspects.

The researchers found that mice genetically programmed to have high levels of osteocalcin don’t gain weight or become diabetic even when fed a high-fat diet, while mice manipulated to lack osteocalcin become fat, secrete less insulin and adiponectin, produce fewer beta cells, and develop type 2 diabetes.

Karsenty says his lab will continue to investigate the role of osteocalcin in glucose metabolism, in animals as well as humans, with an eye toward developing novel therapies for preventing obesity, type 2 diabetes, and related disorders.

How to Build a Bionic Eye

Researchers have created an electronic contact lens that could be used as a display or a medical sensor.

The eyes have it: Researchers built a biocompatible contact lens with working LEDs, shown here. They hope that future versions of the lens can act as a biomedical sensor, or provide a display that is superimposed on a person’s field of view.
Credit: University of Washington

People don't think twice about wearing a Bluetooth headset to have conversations on their cell phones. Well, one day it might not be unusual to wear a contact lens that projects the phone's display directly onto the eye. Researchers at the University of Washington have taken an important first step toward building contact lenses that could do just that. By incorporating metal circuitry and light-emitting diodes (LEDs) into a polymer-based lens, they have created a functional circuit that is biologically compatible with the eye.

"If you look at the structure of a lens, it's just a simple polymer," says Babak Parviz, professor of electrical engineering at the University of Washington. A number of researchers are putting electronics into polymers to build flexible circuits or displays, for instance. "What we realized was, we can make a lot of functional devices that are really tiny, and they can be incorporated into a contact lens to do a lot more than just improve vision," Parviz says.

The team created the electronic lens with two main purposes in mind, he says. One of the goals was to see if it would be possible to build a heads-up display that could superimpose images onto a person's field of view, while still allowing her to see the real world. It would be a sort of augmented reality, explains Parviz. (See "TR10: Augmented Reality.") Soldiers could use the technology to see information about their environment, collected from sensors. Or civilians could use the electronic lens as a cell-phone display, to see who is calling and to watch videos during a commute, although these goals are long term, he says.

Another possible application is to use the lens as a sensor that could monitor chemical levels in the body and notify the user if they indicate signs of disease. Although Parviz won't go into details about the specific sensors that his team is making, he explains that many indicators of health can be monitored from the surface of the eye. The live cells on the eye, he says, are in indirect contact with blood serum, which contains biomarkers for diseases. If a sensor designed to pick up these biomarkers was built into a lens, then doctors could have a completely new, noninvasive tool for disease tests. In addition, the lens could continually monitor changes over time, providing a more complete view of a person's health.

Admittedly, these applications are years away. But Parviz and his team have laid the foundation for the work. In a paper presented at the International Conference of Micro Electric Mechanical Systems in Tucson, AZ, last week, the researchers describe how they created a lens with 16 working LEDs. The lens was made from a polyethylene tetraphthalate substrate--the kind of plastic used in beverage bottles--which was covered with metal wires for connecting the LEDs.

LG HDTV innovation for 2008

A total of 8 new lines of LCD TV's from the Korean manufacturer LG will showcase three main technological areas of development in 2008.

Building upon existing technological and design innovations LG are focusing on their super slim 1.7in LCD, wireless HDTV models and new LED backlighting technology to forge ahead in 2008.

The LG75 series is a 1.7in super slim design that according to an LG spokesperson, is the "epitome" of elegance. The LG75 comes with a unique 'rose red' tint within the "high-gloss" black finish.

The LG75's LED backlight is partitioned into 128 light-emitting diodes which enables local dimming to provide quick response to changing images. An advantage of local dimming ability is reduced energy consumption.

With 47in and 52in models, the LG71 Wireless LCD HDTV Series makes its debut in 2008. The built-in 802.11n Wireless System comes with separate wireless receiver giving a 50-foot radius giving the consumer more flexibility with the positioning of peripheral items.

LG have made a huge impact on the LCD TV market of late, and their latest innovation will surely add to their growing reputation as one of the leading LCD TV producers. LG's new found quality, performance and style is encapsulated by some of their more recent models such as the 32LB75, and their top end LY series of LCD TV's

Sharp LC42XL2E

42in LCD
Excellent all round performer let down by a few minor glitches.
HD Ready: yes
Resolution: 1920 x 1080
Rating: 88%


With a slim (7.5cm) frame finished in black, with a glass bezel around the outside of the screen the LC42XL2E is an indication that Sharp is taking style much more seriously.


With 100Hz processing and 10-bit panels, Sharp's top of the range LC-42XL2E offers some additional features over the entry level LC-42X20E. 100Hz processing doubles the number of frames displayed on-screen for smoother pictures while 10-bit panels increase the number of available colours.

Screen: 42in 16:9
Sound System: Nicam
Resolution: 1920 x 1080
Contrast Ratio: 2,000:1
Brightness: 450cd/m2
Other Features:100Hz processing, TruD, RGB plus, TruSurroundXT.
Sockets: 3 HDMI, 2 Scart, S-video, component video, composite video, PC input.

A 'Full HD' native resolution of 1,920 x 1,080 on the LC42XL2E along with Sharp's 'Underscan' mode enables 1080-line sources (Sky TV, 1080i etc) to be shown in their pure, native fashion. 'Underscan' employs a one-to-one pixel mapping system to exactly match input to screen resolution.

The LC42XL2E has the ability to display films at their intended 24fps (frames per second) rather than the standard (for TV) of 25fps. LCD TV's without this feature will automatically speed up a film very slightly to compensate.

Sharp's TruD picture processing engine has evolved with some tweaking to remove the smear effect or jerkiness on fast moving images as well as enhancing detail and contrast.

The four-wavelength background lighting system (RGB plus) has been designed to ensure that colours are reproduced more accurately.

Acoustically, an on-board SRS sound system is powered by a digital amplifier and two 15-watt speakers.


The high point of the Sharp LC42XL2E's performance can be seen with the excellent black levels it manages to achieve. Blacks are truly black, with good detail visible on even the darkest scenes.

As you would expect, High Definition (HD) material looks superb. Sharp have built a solid reputation for producing some of the most capable LCD TV's in this respect, with picture sharpness and fine detail a match for any flat panel.

What Sharp have not done so well in the past is produce LCD TV's that perform well with Standard Definition (SD) sources. Judging by the Freeview performance of the LC-42XL2E however, this looks set to change. Inevitably, with such a large screen things are not perfect with an element of noise creeping into the picture, but for a 42in screen with the lowest SD quality source, Sharp have made excellent progress. This screen is now a viable day to day Standard Definition display, and even more so with a better quality satellite or cable source.

The only really negative aspect of what is a largely competent performance is colour. No amount of tweaking could produce a colour that we were truly happy with. Whatever the setting, colours seemed over saturated or a little washed out.

The acoustic performance is average with no great perceivable benefit coming from Sharp's proprietary surround sound system.


A fine all round performer frustratingly let down by a few minor glitches.

Sharp LC42XL2E Review

With billions invested in R&D and manufacturing plants, Sharp Corporation is one of the primary driving forces behind the success of LCD televisions. So when rivals Samsung, Sony and Toshiba rolled out their latest models featuring true HD 1920x1080 resolution and motion compensation frame interpolation (MCFI) technology in time for the fourth quarter of 2007, you can bet that Sharp isn't going to be too far behind.

X20E and XL2E are the two latest ranges of Aquos LCD TVs launched by Sharp, with the chief difference being the 100Hz motion technology implemented on the latter. The LCD television I have on review today is the Sharp LC42XL2E, the smallest offering within the XL2E series.

Setup & Design

Setting up the Sharp LC42XL2E took slightly longer than usual, not least because the swivelling table top stand needed to be assembled before mounting the panel on it. Also, whereas most other HDTVs arrive in boxes that could be lifted out of the way to make the setup process that much easier, for the Sharp LC42XL2E we had to reach down to the bottom of the box to take the screen out, which was not helped by the absence of grip handles.

That said, I probably complain too much... after all, unpacking and setting up a brand new flat screen television is usually a once-off effort for most users. Even while lifting the panel out from the box I couldn't help but notice the slim depth profile of the Sharp LC42XL2E; once up and running, the sleek elegance of Sharp's "Slim-line" design truly wowed me.

Sharp LC42XL2E

The "Slim-line" label on the Sharp LC42XL2E refers not only to its depth, but also to the width of the bezel which comes in the form of a polished black perspex frame affixed onto the panel. Measuring around 3-centimetre thick on three sides, the bezel fattens at the bottom to accommodate a Sharp logo at the centre, and some LED indicators (among other things). The bottom end of the bezel is trimmed by a chrome silver strip, which – when viewed from the front – stylishly separates the bezel from the recessed speaker grille beneath.

The speakers necessarily add an uncharacteristic bulge to the rear end of the panel, but on the upside the audio on the Sharp LC42XL2E is an improvement – in terms of dialogue clarity, stereo separation and dynamic range – over the tinny rendition on the XD1E series.


One of the minor criticisms levied against previous Sharp Aquos LCD TVs was the glaring omission of dedicated component inputs – you have to use the supplied adaptor to connect your component cables to the VGA input. Thankfully this has been rectified on the Sharp LC42XL2E: the component input can be found within the rear compartment facing downwards, alongside two Scart interfaces, an aerial terminal, and analogue and digital (optical) audio output:

Downward connections

The rest of the connection ports – including all three HDMI inputs – congregate on the right side of the panel, so be prepared to put the cable clamp (supplied with the television) to use if you want to avoid seeing unsightly cables running down that side:

Side connections

Interestingly, the innermost side compartment was initially covered by a piece of detachable plastic flap, revealing only a HDMI port. As I needed to access the other HDMI port and the VGA input regularly, I simply removed the cover and put it back in the box for as long as I'm using the LCD television:

Plastic Cover Plastic flap detached

Philips 50PFP5532D


Turn Up Your Viewing Experience WIth Integrated Digital Tuner



50inch / 127cm



1366 x 768p



1500 cd/m²

Contrast Ratio

* Viewing Angle 178º H / 178º V
* WXGA Plasma Display Produces brilliant flicker-free progressive scan pictures with optimum brightness and superb colours
* Response Time <3ms

HD Ready

Enjoy the exceptional picture quality of a true High Definition TV signal and be fully prepared for HDTV

* Digital Tuner with Freeview Channels

Receive up to 50 TV channels and 30 digital radio stations – all subscription free! No complicated wiring or additional boxes are needed

* Digital TV

Aspect Ratio

16:9 (Widescreen) Cinematic format, eliminating letter-box borders on widescreen films

* Progressive Scan

Progressive scanning achieves maximum vertical resolution while also eliminating interline flicker and interlace artifacts


Digital Noise Reduction

Ensures deep contrast and natural colours


3D/Digital Comb Filter

Separates combined colour and black & white picture information, to ensure crisp sharp picture detail
* Pixel Plus HD

Provides superbly razor sharp pictures with incredible details and depth from any HD source


Dynamic Contrast Enhancer

Uses video processing and unique dimming backlight technology to deliver deep rich black levels with increased detail


Picture Enhancement

Luminance Transient Improver, Colour Transient Improvement, Contrast Plus, 3/2 - 2/2 motion pull down, Jagged Line Suppression
Active Control

Active Control automatically analyses, 50 times per second, the incoming signal and adjusts the key picture settings

Picture & Text

Picture and teletext side by side

* Sound System

Nicam Stereo

Sound broadcasting system capable of delivering CD-quality digital stereo sound or mono sound

* Sound Output 20 Watts

A larger output results in greater volume

* Equalizer


* Auto Volume Leveller

* Dynamic Bass Enhancement


Incredible Surround

Dramatically magnifies the sound field to immerse you in the audio
* HDMI Two (2)

Can be used for HDTV. Capable of sending high quality, uncompressed audio and video signals
* Component Video Input

A premium connection method and commonly recognised as offering high picture reproduction
* Scart Socket Two (2)

Can carry composite or RGB signals, and the picture quality can vary accordingly
* RGB Enabled One (1)

Can accept picture signals in high quality RGB format
* Composite Video

Merges the information together into a double stream of chrominance and luminance
* S-Video

Offers a medium picture quality by separating the picture signal into colour and brightness information
* Audio Out

RCA phono type connectors (L, R)


Other Features
* Weight 57.5kg
* Dimensions Width = 125.0cm
Height = 81.9cm
Depth = 10.8cm
* Off Timer Switches the TV to standby mode at a pre-determined time

Video Playback


Auto Channel Install

* Electronic Programme Guide

An intelligent on-screen TV listings guide, with easy to use menu systems for scheduled broadcast television programs



1000 page Hypertext
* Remote Control Enables you to operate your equipment from a remote handset