Some 30 researchers from the University of California-San Francisco and the Gladstone Institute of Virology and Immunology have come together to investigate why HIV-positive patients, who are now living longer lives thanks to anti-retroviral drugs, seem to be aging faster than their uninfected peers.

"There's a long list of concerns that people have raised about the effects of chronic HIV infection on different health outcomes," says Dr. Paul Volberding, who as a co-chair of San Francisco's Center for AIDS Research is bringing together this group of scientists. UCSF/San Francisco General Hospital cardiologist Priscilla Hsue, for example, has found that HIV-positive patients (the patients she sees in San Francisco are mostly men) have heart attacks when they're around 50 years old. That's 10 years earlier than when your average, uninfected, man has a heart attack.

Other researchers have found that HIV-infected patients develop dementia younger and kidney failure at a faster rate than their uninfected peers. Volberding says that these patients are also showing accelerated bone loss and accelerated loss of their kidney function. These are all ways in which our bodies normally decline as we age. But in patients with HIV, the decline seems to be faster.

At the beginning, researchers believed that anti-retroviral drugs were causing the aging, but as research has progressed, the thinking has shifted. "The more nuanced recognition now is that maybe some of that was from the drugs," says Volberding, "but maybe some of it was because the drugs were working and patients were living longer and allowing us to see these other effects of chronic viral infection." Even though anti-retroviral drugs can bring the amount of virus in the body down to almost undetectable levels, there is always a tiny amount of HIV replicating inside a patient's body. And Volberding and others believe that this virus could be responsible for the sped-up aging.

UCSF molecular biologist Elizabeth Blackburn, another member of this new group, has spent her life studying the tips of our chromosomes, called our telomeres (pronounced TEAL-oh-meres), and the role they play in aging. Blackburn has found that as we age, our telomeres wear away and shorten. She has studied the telomeres in patients with heart disease and cancer, and now she wants to look at HIV patients' telomeres.

Listen to the Graying of HIV radio report online.

Turkey cannot be the only culprit of induced drowsiness after
a Thanksgiving meal.
With the proximity to Thanksgiving, I thought it would be fun to shed some science on the holiday and turkey is a great specimen to study. It is a commonly held assumption that eating copious amounts of turkey, which contain the amino acid Tryptophan, will trigger the drowsiness felt after a large Thanksgiving meal. However, is this assumption true and if so how is Tryptophan the culprit?

Tryptophan is an essential amino acid. An essential amino acid is one that our bodies cannot synthesize, so it must come from food or supplements. Tryptophan is not only a building block in protein biosynthesis in our body but also a biochemical precursor for synthesizing Serotonin, Melatonin and Niacin. Both Serotonin and Melatonin are factors in inducing drowsiness and sleep. Serotonin is a neurotransmitter that facilitates emotions including desire, body temperature, sleep, appetite and metabolism. Serotonin can also be converted into Melatonin, which further regulates sleep, maintaining the circadian rhythms of several biological functions.

The foods that contain Tryptophan are usually protein-based and include chocolate, oats, milk, yogurt, cottage cheese, red meat, poultry, fish, eggs, along with specific nuts and certain fruits. However, turkey contains the same amount of Tryptophan of other meats. Most meats contain .25 grams of Tryptophan per 100 grams of food while dried egg whites contain 1 gram of Tryptophan per 100 grams of food. Turkey cannot be the only culprit of induced drowsiness after a Thanksgiving meal. If this was indeed true, people would be drowsy after any normal meal containing meat as the levels of Tryptophan are equivalent.

The other two denominators with the Thanksgiving meal are high carbohydrates and fat. An average Thanksgiving meal can have 3000 calories and 239 grams of fat. In comparison, United Nations FAO says the average American consumed 3770 calories per day in 2001-2003. It has been shown in studies in both animals and humans that a meal high in carbohydrates and fat triggers Insulin. Insulin them stimulates the uptake of large neutral branched-chain amino acids, known as LNAA.

Tryptophan does not fall into the LNAA family and thus the ratio of Tryptophan to LNAA in the blood stream increases when Insulin is released into the blood stream. Less competition for transporters in the blood stream results in the uptake of Tryptophan across the blood-brain barrier and the synthesis of Serotonin and Melatonin. This in turn creates the lethargy and drowsiness common after the Thanksgiving meal. Therefore it is not turkey alone that ends in a nap after Thanksgiving dinner. It is a collaborative process. Without the intake of carbohydrates dressed up as rolls, sweet potatoes, mashed potatoes, stuffing and pumpkin pie, the Tryptophan in the iconic Thanksgiving turkey would have too much competition for synthesis. Insulin clears away the competition and in turn isolates Tryptophan in the blood stream enabling it to be readily synthesized. The whole meal is responsible for the drowsiness. The next question that could be posed is this the body’s way to have us slow down to aid digestion?

The Tesla Roadster is an all-electric sports car you can buy today.

General Motors, Chrysler and Ford face an uncertain future. They have been lobbying Congress for a $25 billion bailout, which representatives seem reluctant to grant them. It seems like an odd time to be talking about technological breakthroughs in the automotive industry. But GM is saying that it still intends to come out with its plug-in hybrid, the Chevy Volt, by 2010, and that this new car will "completely reinvent the automotive industry."

Plug-in hybrids run for a certain distance on batteries (so far, hackers have been able to create plug-in hybrids that run for about 10 miles on batteries). After that, they revert to standard hybrid operation, which uses gas and electricity. When you get home in the evening, you plug the car in and recharge the batteries so that the following day you can drive another 10 miles with the electric charge.

Today you can only get a plug-in hybrid by hacking your Prius to add more batteries to it. We filmed members of the Palo Alto nonprofit CalCars doing just this for our QUEST story on plug-in hybrids in 2007. If you're not handy with tools, you can have someone else retrofit your Prius with the necessary battery pack. Luscious Garage, in San Francisco, has started offering this service. They're featured in today’s QUEST story "Waiting for the Electric Car," which explores why all-electric everyday cars remain an elusive goal. The limiting factor is the difficulty in making a battery that is powerful, long-lasting and cheap. QUEST goes behind the scenes to a battery lab at the Lawrence Berkeley National Laboratory in Berkeley to find out what goes into the making of a lithium-ion battery and why it’s taking so long to make one that can power an all-electric car, or even a plug-in hybrid that can go for more than 10 miles on its electric charge.

Watch the Waiting for the Electric Car television story online.

We see or hear about explosions practically every day on TV–
most people have no idea what an explosion really is.We were asked to surrender all of our communications devices before entering the High Explosives Applications Facility at Lawrence Livermore National Laboratory in Livermore, CA. After handing over our cell phones, checking our IDs and getting our badges, we were led through a labyrinth of Cold War-era concrete hallways where there is a definite atmosphere of secrecy and caution.

It’s true that the majority of the work done there is in support of Department of Defense and Department of Energy programs. But contrary to what one might imagine, the scientists there are work that goes on there isn't ALL about figuring out how to protect the U.S. from Communism. The scientists here are chemists, physicists and engineers who are delving into everything from warhead electrical systems to enhanced mammography.

We’re led into the "firing chamber" to meet our explosives guy, Jon Maienschein, who has promised to blow something up for us. I’m excited. It’s hard to make a bad TV segment when an explosion is involved. If you watch television, you will see that many shows live and die by that rule. Maienshein is surprisingly mild-mannered for a guy who blows things up for a living. After interviewing him for about 30 minutes on camera, we finally had a very basic understanding of what’s happening during a detonation.

There are several different kinds of explosions: chemical, natural, mechanical and nuclear, electrical, astronomical, etc. The most common "artificial" explosives are chemical usually involving a violent, rapid oxidation reaction. The fine folks at LLNL demonstrated just such and explosion for us then gave us the super-cool, ultra-slow-motion footage that they shoot in order to study what actually goes on inside an explosion.

We see or hear about explosions practically every day on TV, the movies and in the news, most people have no idea what an explosion really is. What’s happening on the chemical and molecular level? And how do the people who know about explosives actually study explosions? And why is it necessary to understand this stuff? The whole thing is surprisingly complex.

Watch the Inside an Explosion television story online.

I love my dog. For the past ten years, through thick and thin, Brodie has been my happy sidekick, trusted confidant, eager hiking partner and beloved friend. Most of all the kid makes me laugh. He is, I am prone to say, "a glorious twit!" And even though he is getting up in years he can still out-swim, out-surf and out-dig any dog on the beach. I am fat with the tales and wagging tails of our adventures and misadventures. He was the chaperone when my wife and I had our first date. And if I had my way he would have been the ring-bearer at our wedding. My daughter's first word was "Bro-die!" And it swells my heart each morning when he pads into her room, and she sleepily exclaims "Woof-woof." He is simply a valued and integral part of my family.

As special as my relationship with Brodie is to me, I know it's not unique. Many of us know the startling joy of being woken up by a wet nose or a slobbery lick on the cheek early Sunday morning. Everyone who knows and loves dogs will happily tell you about their favorite pooch. The Quest team has Bailey and Carrot and Skinny and Shadow and Bro. We talk about them as we would talk about our children. And even though I haven't met all of the Quest pups, I know them through their favorite people. And that brings me to Quest TV Producer Amy Miller's wonderful German Shepherd dog, Pierre. Pierre was battling cancer as we went into production on this story. Then sadly, by the time we completed this Quest episode, Pierre had been laid to rest. It was a heartbreaking blow to our friend and colleague. And I think all of us felt and understood her loss. Therefore, it is for Pierre that I dedicated this story and now think fondly of all our canine friends past, present and future.

Our time with them is sweet but painfully short. Enjoy every walk, every game of fetch at the park, every romp on the beach and every quiet moment with them curled up under your feet. Put up with their occasional mischievous misdeeds- the drinking out of toilets, getting into the garbage or chewing up your slippers. Remember, they're all good dogs. Smile and scratch them behind the ears. All they give is love and that is all they desire back… that and maybe a little treat.

Watch the Fido Fights Cancer television story online. Also, don't miss our set of behind-the-scenes photos for this story.

People with the delta 32 version of the CCR5 gene are more
resistant to HIV infection.
Doctors announced in Berlin that a man who received a bone marrow transplant for leukemia was now also free of his HIV infection. Looks like this patient's luck is finally turning around!

Both leukemia and AIDS are diseases of the blood. Bone marrow transplants cure leukemia by permanently replacing the patient's blood with the donor's. This eliminates the cancerous blood cells and so cures the cancer.

One "side effect" of a bone marrow transplant is that the patient's blood cells now have donor's DNA. This sometimes makes for problems at crime scenes (and interesting CSI episodes). But here the doctor used it to the patient's advantage.

Scientists have known for a long time that people with two copies of a certain version of the CCR5 gene, the delta 32 version, are much more resistant to HIV. Their AIDS symptoms also tend to progress much more slowly.

So the doctors reasoned that if the patient were going to receive a bone marrow transplant anyway, why not give him one from a donor with two copies of delta 32? And that’s just what the doctors did.

Over 20 months later, there is no sign of the patient’s leukemia. And no sign of HIV either.

We'll still need to wait and see if this result holds up. But even if it does, this cure isn't for everyone. It is expensive and very risky.

Around 1 in 4 patients dies from bone marrow transplants. I'm no M.D., but I would guess that patients at the later stages of AIDS would do even more poorly.

But if the result does hold up, then maybe scientists can figure out how to do something similar without the bone marrow transplant. Maybe they can find a medicine that can shut down the CCR5 gene and so get the same effects as the delta 32 version. Another possibility is gene therapy.

The idea would be to change the patient's CCR5 gene into the delta 32 version. This would be really hard.

Gene therapy is pretty good at adding a working gene to a cell. It is not very good at changing a patient's gene. This means it would not be easy to turn a CCR5 gene into the delta 32 version in a patient's bone marrow cells.

But maybe there is another way. The CCR5 gene is not the only way to be resistant to HIV. Another way is by having extra copies of the CCL3L1 gene. Perhaps scientists could add extra copies of this gene to a patient's bone marrow cells and help at least slow down HIV. This seems doable with gene therapy.

The Eye in the Sea. Credit: MBARI.

The Eye in the Sea is one of the coolest, gee-whiz scientific projects you'll see. It's part of the Monterey Bay Aquarium Research Institute's so-called MARS project (that stands for Monterey Accelerated Research System). MARS is an undersea laboratory, set up deep on the sea floor about 30 miles offshore from Monterey.

The Eye in the Sea is one of the first research projects to be hooked up to MARS. It uses a small amount of red light to view what’s happening on the ocean floor, about 3,000 feet below the surface. The images travel through 32 miles of cable and go back to the control center on land, where researchers view real-time video of life at the "benthic" level – that is, a voyage to the bottom of the sea.

And you're going to be able to take that voyage, too.

Schoolchildren, teachers and eventually the general public will be able to see the spindly-legged crabs calle spiny kings, or the eel-like hagfish, or the giant, dark, blob-like Pacific sleeper shark.

The Eye in the Sea becomes operational in January, and researchers expect to have their school program up and running by late January or early February, depending on the success they have hooking up Eye in the Sea to the metal hub out in the middle of Monterey Bay.

All of that means that the public will be able to go to www.mbari.org beginning sometime in February and view video-cam images from half a mile deep on the sea floor.

How cool is that?

Watch video from the Eye of the Sea in the Underwater Laboratory audio slide show online.

Are there more actually more stars in the sky, than there are
grains of sand on all the world's beaches?
I think most of us have heard that perennial estimate of the number of stars in the Universe being greater than all of the grains of sand in all of Earth’s beaches.

Sitting on Limantour Beach at Point Reyes awhile back, watching the waves slosh in and out, listening to gulls and feeling very lazy, I found myself looking about me at all that sand, and wondering how it could possibly be true. Reaching out, scooping up a mere handful of grains and letting–what?–a few hundred thousand of the would-be star proxies fall through my fingers, the notion seemed even more absurd.

Raising my eyes from the bit of the cosmos cupped in my hand and taking in the comparatively vast reaches of sand about me–a hundred or so feet between me and the waves, at least a mile or two of beach visible to the north, another stretch to the south, and who knows how many feet of depth beneath the surface? I simply couldn’t believe it. So, I pulled out my journal and started to write down some figures, working out the problem rationally.

So, is it true? Well, here's what I came up with:

Stars: Astronomers have estimated that there are about 200 billion stars in the Milky Way Galaxy. Galaxies come in many sizes, both much larger and considerably smaller than our home galaxy. I don't know what the average number of stars in each galaxy is, but for the sake of this calculation I chose a conservative 10 billion stars per galaxy. Astronomers have also estimated that there are between 50 billion and 100 billion galaxies in the Universe, based on observations made by the Hubble Space Telescope. Again being conservative, I chose the lower figure of 50 billion. So, with those numbers, I calculate a number of stars in the Universe at 10 billion times 50 billion, or 500 billion billion—or in exponential notation, 5 X 10²⁰.

So how does the number of sand grains in the entire world's beaches stack up against that?

To get to that number, I had to do some estimation. First, pulling some numbers out of the air, I decided that an average sandy beach is 30 meters wide (about 100 feet), and 10 meters deep (about 33 feet). Some beaches are wider, some much less so. I don't imagine that the sand on the average beach is as deep as 10 meters—but I've never taken a shovel and found out, either.

Next, I assume that the average sand grain is a millimeter across, giving it a volume of about a cubic millimeter. With that number, I figure the sand grain density to be 1000³, or one billion, sand grains per cubic meter of beach.

The final piece of the equation–after density, width, and depth–is length: the total length of beach shorelines in the entire world. Here's where I made some serious assumptions. Starting with the total length of shorelines of all continents and islands in the world, I got a figure of 356,000 kilometers from the CIA World Factbook. That's 356 million meters.

Now here's where my estimate becomes truly conservative. In my final calculation, I assumed that all 356 million meters of world coastline consisted of sandy beaches– which is not the case, of course; there are plenty of coastlines that are rocky, pebbly, gravely, ice-covered, or sheer cliffs, all without much, if any, sand.

So what were my results? Well, doing the math, 1 billion grains per cubic meter times a 30 meter beach width times a 10 meter beach depth times a 356 million meter beach length and assuming 100% of the coastlines consist of my hypothetical average beach, I get:

1 billion x 30 x 10 x 356 million x 100% = 1.068 x 10²⁰ grains of sand

Compared to the estimate of stars in the Universe, that's about 5 times as many stars in the Universe as grains of sand in all the beaches in the world! I guess the old adage was not only right, but somewhat of an understatement…

But it's all a thing of scale. I also calculated that there are about 3000 times as many water molecules in a glass of water than there are stars in the Universe…

Is this you in the kitchen?Here in the Bay Area, we're known the world around as foodies, especially given the recent popularity of the Slow Food Festival. As we approach the biggest food holiday of the year, it's a great opportunity to think about the science behind all of these scrumptious meals.

Last year, I stumbled across a new series of lectures on Food Ethics & Environment at Stanford University. Headlining the series was the incomparable Michael Pollan, who led an interactive discussion on the evolution of food culture in the U.S. I was amazed at the level of passion in the audience and moreover the knowledge level of the audience. I left inspired to take my time with food and eat a little healthier (that worked for about a week).

This year, Stanford again delivers a stellar lineup. Over the next few weeks and months– there will be discussions ranging from water, the affect of global warming on our food, fair trade coffee, and even a conversation with a organic farmer (it's Joel Salatin, one of the heroes from the "Omnivore's Dilemma").

So before you give thanks next week, consider a heaping serving of food science.

All events are free. They take place at the Annenberg Auditorium on the Stanford University Campus. The events are usually held on Thursday nights at 7pm. For more info, check out the Stanford Ethics Website.

Photo: John Albers-MeadWe put out a call for submissions for this Your Photos on Quest segment a little late. As a result, we only got a handful of submissions. Thankfully, John Albers-Mead was one of them. Everyone who looked at his photos inevitably ended up calling a nearby colleague over to their computer screen saying, "Wow, you've GOT to take a look at this photo!" We were amazed by the details, the light, the colors, the textures and the compositions of his images. And we were especially blown away when we learned that he does not do any underwater photography! Looking at his photos, you would swear that his camera is in an underwater housing. In fact, we really didn't believe it and I ended up asking him about it three times just to make sure.

If you've ever tried to photograph something beneath the water's surface, you know how challenging it is to make sure there's enough light on the object to reveal its details but at the same time, to be careful not to get reflections on the water, thereby obstructing the view. It takes patience. And time. Albers-Mead says he composes the whole photograph based on the light. At one point in the interview, he told me (with the giddiness of a child at Christmas) that one time, he lay at the lip of a single tide pool for 2 hours waiting for the right light. He was perfectly happy just observing the tide pool drama unfolding, in which a couple of nudibranchs munched on each other. He is the quintessential "amateur," meaning he makes these trips to the tide pools a couple of times a month for the LOVE of it.

He shares his photos on Flickr and has quite a following. But he is also a docent at the Fitzgerald Marine Reserve in Moss Beach. If folks have an interest in tide pools, this is the place to go. Of course, this area is also prime real estate and it wasn't so long ago that this area was slated for development. Now, with rising sea levels and temperatures, as well as the acidification of ocean water, these tide pools may not be around forever. But while they are, I would recommend looking at John Albers-Mead's Flickr set BEFORE you go see them in person. I guarantee that you will have a deeper appreciation for the tide pools when you first see them through his loving eyes.

Watch the Your Photos On Quest: John Albers-Mead television story online.

For those of you who are interested in entering your photos for consideration in future YPOQ episodes, sign up for our email newsletter to get an announcement for the next submission call, or head on over to our Flickr photo group for KQED QUEST.