Meanwhile, on Venus...

Lately, Earth and Mars seem to get all the press, but the NASA has ignored Venus since the NASA's Magellan mission used radar to map the planet in 1994 . Venus is Earth's neighbor, on the side closer to the Sun. The planet has roughly the same mass, size, and composition as Earth. Evidence shows that Venus was once partially covered by deep oceans of water. Today, Venus is unimaginably hot, with only a little water left on its surface. How could two planets that were once so essentially alike end up so different?

This week, the European Space Agency (ESA) released eight papers in Nature magazine documenting the findings of the Venus Express mission, their unmanned probe launched in 2005. The ESA has been building their understanding of Venusian weather, which to Earthlings is astounding: above the planet's 460-degree-C surface, the Sun’s energy blasts thick sulphuric acid clouds through an atmosphere that is about 95 percent carbon dioxide.

On Earth, a small amount of atmospheric carbon dioxide warms the surface, which is tempered by vast oceans. On Venus, the thin spots of surface water are vaporizing into space under intense heat. With an atmosphere composed mainly of carbon dioxide, no oceans to cool lava that flows to its surface, and a closer proximity to the sun, Venus experiences an extreme greenhouse effect.

Venus' inhospitable conditions ruins our chances of finding any remaining record of past life there, and makes the possibility of landing an astronaut there a pipe dream. link

Beer fridges are widening our carbon footprints

According to a researcher at the University of Alberta, the secondary refrigerators found in many Canadian households are significant contributors to greenhouse gas emissions.

In Canada, one in three households have a second refrigerator, and most of these second refrigerators are used to keep beverages cold. Beer fridges tend to be older and less energy efficient, 65 percent are more than 10 years old. According to a Canadian researcher, secondary refrigerators in Canada consumed at least as much electricity as 100,000 US homes.

Although the study did not include the US, it's fair to assume that US households contributing to greenhouse emissions in a similar way. The According to the National Resources Defense Council, 98 to 99 percent of US homes have at least one refrigerator, and 18 percent of those have two or more refrigerators. link

Emryonic stem cells - without the embryos

Embryonic stem cells are pluripotent-- they have an almost magical ability to grow into any kind of cell and perform any function. There is a good possibility that some day we may use cells like this to heal injuries and deceases. Until recently, the only way to get these cells was to remove them from the cells of a embryo, a process that is fatal to the embryo and controversial to many.

It was reported on November 20 that a method was developed for making pluripotent stem cells from ordinary skin cells, with no need for an embryo. Two different scientific teams developed the method independently, using specialized viruses to deliver four genes to the skin cell's genetic code. Adding four genes is all it takes to make a embryonic-like stem cell from a skin cell.

Anytime genes are added to normal cells, there is a risk that the cells can grow cancerous. But, researchers are confident that they will soon find a way to switch the cell's genes instead of adding to them, removing the cancer risk.

Having a method for making pluripotent stem cells without using embryos will extinguish the controversy that beleaguers stem cell research. "People working on ethics will have to find something new to worry about," says stem cell researcher Jose Cibelli of Michigan State University. link

Why do the trees change color in the fall?

It seems a fairly obvious question for this time of year. My daughter asked me this question last week, and I was embarrassed that I didn't know what to tell her.

According to News@nature.com, color change in leaves is not very well understood. The predominant theory is that leaves change their color in order to recycle the last bit of nutrients from their leaves before they are lost. Thus, trees grown in areas with less soil nutrients will produce more brilliant leaf colors.

As the weather turns colder, the trees switch to winter hibernation mode. The green chlorophyll in the leaves breaks down and disappears, revealing the yellow carotinoids that have been lurking among the chlorophyll all summer. The brilliant red color that people admire comes from a pigment called anthocyanin, which trees produce in autumn. Why trees expend their precious energy producing anthocyanin is still a matter of study and debate. It is believed that anthocyanin acts as a sunscreen, protecting leaves which are more vulnerable to sun damage after the chlorophyll is gone. The protected leaves can stay on the trees longer, allowing leaf nutrients to be absorbed into the other parts of the tree. link

Gravity victorious in rocket competition

NASA held their 2007 X Prize Cup rocket expo this past weekend near Alamogordo, New Mexico. The weekend's big event was the Northrop Grumman Lunar Lander Challenge, offering 1.35-million dollars in prize money to the company that can demonstrate a new space vehicle capable of landing humans on the moon.

Of the nine companies that registered for the event, only Armadillo Aerospace of Mesquite, Texas was ready to go on launch day. Armadillo is headed by John Carmack, the creator of the video game Doom. Their entry, Module 1, failed the test the first two times and exploded on the third. Interestingly, Armadillo was the only entry to show up for the 2006 competition, and its entry crashed that year, too.

Why is it that a team can't meet the challenge? It's not exactly rocket science. link

Some Neanderthals were redheads

The journal Science reports that at least 1 percent of Neanderthals were fair-skinned redheads. This adaption likely helped the Neanderthals of the high latitudes synthesize vitamin D with less sunlight.

Separate teams isolated a version of a gene called mc1r from the fossils of two different Neanderthals, one 43,000-year-old fossil from Spain, and another 50,000-year-old fossil from Italy. The Neanderthal version of the mc1r gene is similar to a gene found in humans that have fair skin and red hair.

The Neanderthal version of mc1r is not found in humans, which confirms that the gene samples were not mistakenly taken from a human. This also strengthens the currently-accepted theory that humans did not evolve from Neanderthals. link

Engineered virus shrinks tumors

Viruses have been known to shrink tumors. A reduction in tumor size can be observed after vaccinating a cancer patient, because vaccinating introduces a small amount of virus. The challenge has been to get enough virus cells to target the tumor without damaging healthy cells.

By genetically modifying the pox virus, David Kirn at Jennerex Biotherapeutics in San Francisco has engineered a special virus to seek and destroy tumors. Kirn's genetically-modified virus spreads more easily within tumors thanks to a tail composed of a protein called actin. Kirn has also modified the virus so that it is unable to produce an enzyme called thymidine kinase, without which the virus is unable to replicate and damage healthy tissue. Since cancerous cells contain an abundance of thymidine kinase, it is easy for the modified virus to multiply within tumors, and once the virus enters a cancer cell, it replicates itself until the cancer cell bursts. The third modification to the pox virus makes it produce a signalling molecule called cytokine, which attracts the body's immune cells towards tumors.

Clinical trials on the virus treatment was conducted with 13 patients with advanced liver cancer. The patients were so advanced that all previous therapies had failed, and they had a life expectancy of only three to four months. Beginning in July 2006, researchers started treating by administering the engineered virus directly into the participants' tumors every three weeks.

Seven of the participants survived for more than eight months, and three are still alive today, over 15 months later. The virus shrank the tumors of 10 of the 13 participants, including five whose tumors were reduced more than 50 percent. The only notable side effect experienced by the participants was temporary flu-like symptoms. link

Predicting global climate change: mission impossible

In the current issue of Science magazine, two University of Washington scientists suggest that we "call off the quest" for predicting global temperature changes, and that political decisions should not be made based on climate models.

For 20 years now, scientists have been working on predicting how much the average global temperature will increase when carbon dioxide levels reach double the pre-industrial levels. For all the effort, the predictions are not getting any more accurate -- current estimates range between 2.0 and 8.0 degrees C.

The article states that even the best computer models have too much uncertainty; this uncertainty comes from feedbacks in the system that change the way the system changes. For example, the sun is melting the polar ice caps. As they melt, they reflect less of the suns energy, changing the balance. These types of feedbacks cause uncertainty.

The article does not dispute that global temperatures will continue to rise; but nonetheless, the article will likely fuel the critics of the the climate change movement. link

Carbon dioxide emissions are still climbing

The greenhouse gas problem is nothing new, and you might think we've begun to at least slow our increasing carbon dioxide emissions. However, a paper published in the Proceedings of the National Academy of Sciences discloses more inconvenient truth.

In 2006, global carbon dioxide emissions resulted in a release of 9.9-billion tons of carbon into the atmosphere; 35-percent higher than the 1990 carbon emissions. In the atmosphere, carbon concentrations are now increasing at a rate of 1.93 parts per million (ppm) each year. This is the highest rate of increase since carbon monitoring activities began in 1959. The current rate of annual increase is considerably higher than the 1.58-ppm average for the 1980s and the 1.49 ppm for the 1990s.

Dr. Pep Canadell, the study's lead author and the Executive Director of the Global Carbon Project, explains that emission rates have likely risen as a result of the increase in global population and wealth. We have yet to find a way to increase increase global wealth without increasing carbon emissions rates. In addition, there has been a slowing of the effectiveness of global carbon-absorbing systems, such as rainforests and oceans. link

Flu spreads faster in cold weather

We can tell our grandmas they were right. New research from the Journal of the American Medical Association shows that the flu virus spreads easier in cold and dry weather. We used to explain that the increase in indoor activity in the colder months makes the flu season a cold-weather event. But, that's not the whole story.

The flu virus is exhaled from the body attached to aerosol water droplets. In as series of medical studies, the flu was spread through a population of guinea pigs. Since guinea pigs were in separate cages and do not sneeze or cough, the virus was spread only through breathing. Results showed that the flu spread much faster in colder air and in drier air.

When the air is dry, water aerosols and viruses move efficiently. But in damp air, the virus can't stay airborne; the aerosols containing the virus tend to combine with other water aersols and settle out of the air. Warm air can hold more moisture than cold air, so cold air tends to be drier and is better at spreading the flu.

After further study of the ginea pigs, researchers concluded that the spread of flu is also affected by the health of the mucus layers that line the nose and throat. In warm conditions, the mucus layer traps viruses and carries them from the body. Cold air damages the mucus layer, making the it more viscus and hindering the ability of the mucus to rid the infection.

So grandmas, bring on the chicken soup. link

A step closer Alzheimer's detection

More than 5-million North Americans are diagnosed with Alzheimer's decease, and a quarter of a million more are estimated to be living undiagnosed. Currently, doctors diagnose Alzheimer's by the patients' behavior and by eliminating other possible deceases. The only fool-proof way to diagnose the decease is after it's too late - through autopsy of the brain.

Researchers at the Stanford School of Medicine studied concentrations of communicode proteins the blood of living patients. The communicode is a set of 120 proteins that human cells use to communicate with each other. It is thought that the decease damages the communicode proteins in the brain and that these damaged proteins circulate throughout the bloodstream. Doctors diagnosed 20 patients with or without Alzheimer's. The blood test and the doctors' diagnoses agreed in 18 of 20 patients.

Unfortunately, even if diagnosed early, there is no current treatment for the decease. link

Mars orbiter snaps new high-resolution color images

Searching for the next Mars landing sights, the Mars Reconnaissance Orbiter captured 143 high-resolution color images of the planet's surface. The pictures are the first color images from the High Resolution Imaging Science Experiment (HiRISE) camera aboard the orbiter. The images are quite striking; they illustrate the unique geological history and chemical make-up of the planet's surface.

The next landing of a Mars rover will be in 2009. The unmanned rover, called the Mars Science Laboratory, will carry the next generation of instrumentation, searching for conditions that can or had once supported life on Mars.

Meanwhile, Opportunity and Spirit, the first two Mars Rovers, are still sending back data after more than three years of service. Not bad, considering the missions were expected to last three months. The aging rovers are beginning to fatigue due to the daily temperature swings of 200 degrees F. link