Monday, May 30, 2011

"Scientists Debunk Theory on End of 'Snowball Earth' Ice Age" - Science Daily, May 26, 2011.

There was an ice age, called the Marioan ice age or 'Snowball Earth', that happened around 600 million years ago and there is a theory of why and how it came to such a sudden and abrupt end. Scientists say that it happened with "large amounts of methane, the bubbling through ocean sediments, a strong greenhouse gas, and from beneath the permafrost and heating the atmosphere."

Samples of cap dolostone in south China were found and that is the main physical evidence there is to support this theory. These are known to have less of the carbon-13 isotope than found in normal carbonate rocks. Dolostone is a type of sedimentary rock that consists of dolomite, a carbonate mineral and it is called 'cap' dolostone when it overlaps a glacial deposit. The theory states that these rocks formed when methane bubbled up from below and was oxidized by microbes, "with its carbon wastes being incorporated into the dolostone", causing the end of the ice age. This made sense because methane tends to be low in carbon-13 and if the carbon-13-depleted methane was turned into rock, that rock would also be low in carbon-13. However, this idea was quite controversial since there was no trace of previous isotopic evidence in carbonate rock as back in time as the ice age happened.

A team from the California Institute of Technology (Clatech) published an article in the journalNature saying it is wrong because of the testings they have done. Their data showed that the rock that was the main evidence that the theory was based on had formed millions of years after the ice age had ended and in temperatures so high that were unbearable for any living organism.

John Eiler, the Robert P. Sharp Professor of Geology and professor of geochemistry at Clatech, and one of the paper's authors, developed a technique used to tell the rocks' "story" that looked at the way the isotopes, like the carbon-13 in the dolostones, group together in crystalline structures like bone or rock. They proved that this grouping of isotopes in dependent to the temperature of the environment in which the crystals form; the hotter the temperatures are, the less grouping there is, and the colder the temperatures are, more grouping occurs.

"The rocks that we analyzed for this study have been worked on before," says Thomas Bristow, the paper's first author and a former postdoc at Caltech who is now at NASA Ames Research Center, "but the unique advance available and developed at Caltech is the technique of using carbonate clumped-isotopic thermometry to study the temperature of crystallization of the samples. It was primarily this technique that brought new insights regarding the geological history of the rocks."

Eiler says, "the carbon source was not oxidized and turned into carbonate at Earth's surface. This was happening in a very hot hydrothermal environment, underground." We know it happened at least millions of years after the ice age ended, and probably tens of millions. Which means that whatever the source of carbon was, it wasn't related to the end of the ice age."

This topic brings up many questions since scientists say that the only evidence there is, is the carbon-isotopic evidence of a Precambrian methane seep. Scientists are not just trying to find out how the Marinoan ice age ended, but also about the amount of methane of the Earth and the biogeochemistry of the ocean.

What interested me about this article was that, at first, when I read the title I though it was about the end of the world and I started reading the article, but then I realized what it was really about and it got me more interested. I think that it is fascinating how chemistry and geology are related because, in this case for example, they are connected by how the rock is formed and how a chemical reaction occurred for the ice age to have happened. Even though I did not understand some of the explanations about how the rock was formed since I have not studied chemistry in that level of depth, I found it quite an appealing subject and I want learn more about it. Learning about what happened 600 million years ago is very fascinating and if something like this happens again, in the future we might be going through another ice age...

Sunday, May 1, 2011

"Monkeys, Too, Can Recollect What They've Seen, Study Suggests" - Science Daily, April 29, 2011.

According a report publish on April 28, 2011, in Current Biology, monkeys are able, just like humans, to recollect memories from the past and put them together to create an image of what something used to look like. Researchers discovered that monkeys are able to recall things , such as simple objects they have seen in the past and even draw an image of them in a touch screen. They say that the memories from humans and monkeys are similar then they knew.

As the researchers say, there is a difference between recognition and recall. To recall an object is to remember what an object looks like and remember it without it being present in the moment, unlike recognition. "Recall is necessary for planning and imagining and can increase the flexibility of navigation, social behavior, and other cognitive skills."

"The ability of monkeys to recall these shapes flexibly suggests that they might be able to recollect other types of information that would be useful to them in the wild," said Benjamin Basile of Emory University. "It's exciting to speculate that they may be able to recollect the appearance of monkeys they know, what favorite foods look like, or the path they would have to take to get to a water source. Maybe it's often just easier to recognize the monkey, the food, or the landmark in front of you. What we do know is that they do seem to have the ability to recall information in the lab."

Though recall and recognition tests give to humans showed that humans use different types of memory than primates, scientists had to create different tests for primates also because primates cannot draw or talk. One of the tests created for monkeys by Basile and Robert Hampton consisted of five trained rhesus monkeys in a recall test who had to, in a touch screen, produce an image of a simple object just from their memory. Those objects included two or three boxes on a grid and then, after a short while, part of the object would appear in a different part of the screen and the monkey would have to draw the part that was missing.

In the same testing conditions, humans and monkeys showed that they do better in recognition tests than in recall tests and that their recalling ability slowly decreased and that the monkeys ability to recollect did not depend on the language and may have been present 30 million years ago in our common ancestor.

"Recollection and familiarity likely evolved because they solved functionally incompatible problems," the researchers wrote. "For example, familiarity does not support detailed memory for context, but it is quick and resistant to distraction. Recollection is slower and more vulnerable to distraction but supports a more detailed and flexible use of memory. Familiarity might better allow rapid responses to foods and predators under distracting conditions, whereas recollection might be necessary to access knowledge of distant food locations or past social interactions for planning future behavior."

I found this article interesting because I have researched about how monkeys and humans share a lot in common and I think it is fascinating. There also some studies that show that monkeys doing the same test as humans about recalling and recognizing objects do better than humans and it was also proven that monkeys have better memory than humans. Monkeys and humans share the same common ancestor about six million years ago and share DNA and monkeys outsmart humans in different tasks such as ones that involve memory. Maybe in the future monkeys and primates will rule the world...

Tuesday, March 29, 2011

"Satellites Detect Extensive Drought Impact on Amazon Forests" - Science Daily, March 29, 2011.

New research funded by NASA showed that the Amazon basin and its forests in South America have reduced their amount of greenness due to the "record-breaking" drought in 2010.

"The greenness levels of Amazonian vegetation -- a measure of its health -- decreased dramatically over an area more than three and one-half times the size of Texas and did not recover to normal levels, even after the drought ended in late October 2010," said Liang Xu, the study's lead author from Boston University.

Scientists are worried that this massive drought with low levels of rainfall and climate change the rainforests will turn into woody savannas and grasslands. This could accelerate the process of Global Warming because of all the carbon stored in the rotting wood would be released into the atmosphere. The United Nations' Intergovernmental Panel on Climate Change (IPCC) gave notice of possible droughts that could occur with more frequency in the Amazon region in the future.
All the research and studies were done by a group of international scientists that had been working on this for more than 10 years using data from the NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) and Tropical Rainfall Measuring Mission (TRMM). Maps were created showing the greenness of the area since the 2010 drought and a great decrease in the vegetation was noticed. They also showed that the 2010 drought reduced the vegetation approximately by 965,000 square miles in the Amazon, around four times bigger than the 2005 drought.

"The MODIS vegetation greenness data suggest a more widespread, severe and long-lasting impact to Amazonian vegetation than what can be inferred based solely on rainfall data," said Arindam Samanta, a co-lead author from Atmospheric and Environmental Research Inc. in Lexington, Mass.

This drought also affected the water levels in some rivers across the basin in August 2010 and reached their record on the lowest water level in October that year. This year 2010 was the driest in comparison to the 109 years that the water level has been measured in the Rio Negro at the Manaus Harbor.

In the summer of 2010, a severe drought began to appear and scientists started researching with the NASA Earth Exchange (NEX), which is "a collaborative supercomputing environment that brings together data, models and computing resources". With this, they were able to get satellite pictures of the region and a full image of the impact of the drought. The research was done by January 2011.

"Timely monitoring of our planet's vegetation with satellites is critical, and with NEX it can be done efficiently to deliver near-real time information, as this study demonstrates," said study coauthor Ramakrishna Nemani, a research scientist at Ames. An article about the NEX project appears in this week's issue of Eos, the weekly newspaper of the American Geophysical Union."

What interested me about this article was the fact that it is about the environment and how it is being affected by different natural disasters, in this case a drought. The Amazon basin is one of the ecosystems with most biodiversity in the world and it is being destroyed. It is very important that we take care of the environment to preserve it and make it a better place to live, because if we do not take care of it, the consequences could turn against us too. Taking Global Warming as an example, we can see that as the Earth is heating up droughts occur and we must take action to slow it down. There are many other consequences of Global Warming apart from droughts, such as the rising of the sea levels and the thinning of the ozone layer. These causes could be very dangerous, but if we prevent them from happening we can live in peace with nature. We can do so by becoming a more environmentally friendly community by, for example, reducing, reusing, and recycling materials.

Tuesday, March 1, 2011

“Stem Cells from Amniotic Fluid: Reprogrammed Amniotic Fluid Cells Can Generate All Types of Body Cells” - Science Daily, November 25, 2010.

Scientists have discovered that reprogrammed amniotic fluid stem cells can evolve into any kind
of cell of the body. Since they have this ability, they are expected to cure and treat many diseases
in the future, but ethical conflicts rise due to the fact that the main source for these stem cells is
embryos. Scientists at the Max Planck Institute for Molecular Genetics in Berlin have been able
to convert the amniotic fluid cells into pluripotent ones and they are very similar to embryonic
stem cells, but the amniotic fluid cells are able to “remember” where they came from. Today, the
abilities of embryonic stem cells can be used in adult stem cells and it is done by reprogramming
these cells to then convert them into “induced pluripotent stem cells” (iPS cells). After this
procedure, the cells have the ability to reproduce endlessly and to evolve into any type of cell in
the body. Apart from their pluripotency, iPS cells can “remember” the original cell type “from
which they were generated” and during the reprogramming of these cells, there are genes that
can be turned on or remain active. Other results from the investigation show that the stem cells
that come from different tissues are most likely to follow their “predestined developmental path
upon spontaneous differentiation.”

"We don't know just yet whether this donor-cell type memory will have an impact on possible medical
treatment, or which type of somatic cell-derived iPS cell will be most suitable for treatment," cautions
Katharina Wolfrum of the Max Planck Institute for Molecular Genetics.

Amniotic stem cells have several benefits over other types of cells, for example, the fact that
they are examined often to enable the detection of diseases. Also, since the fetuses are just a few
weeks old, they do not have many environmentally-induced mutations and are more genetically

"This may mean that it is possible to reprogram these amniotic fluid cells faster and more easily than
other cell types, making amniotic fluid-derived iPS cells an interesting complement to embryonic stem
cells," explains James Adjaye of the Max Planck Institute in Berlin.

Furthermore, amniotic fluid cells can be obtained for the cellular reprogramming and prepare the
cells for their intended use before the baby is even born and the pregnancy is going on.

"This would make it possible to test which drugs work for a baby and whether they are tolerated, before
that baby is born. Moreover, in the future, sick newborns can be treated with cells from their own body,"
says Adjaye.

What interested me about this article was the fact that it is about stem cells. Since this is an issue
we have already discussed, I thought it would be interesting to research more about it. Stem cell
research is a very controversial issue that is debated all over the world and has both its benefits
and limitations. I, personally, think that it is more beneficial than limiting because stem cells can
be used for treating and curing diseases such as, Alzheimer’s and spinal cord injuries, which are

diseases that affect many people worldwide and that still have not been able to find a cure for
them, so stem cell research is important to those people who suffer from these diseases. Even
though the main source of stem cells is embryos, I think that one life of one embryo is worth
saving millions of others with the researching for the cure of these diseases that may be treatable.

Sunday, January 30, 2011

"Hubble captures oldest galaxies ever seen", La Patilla, January 26, 2011;, January 29, 2011.

The Hubble Telescope recently has spotted a galaxy that scientists investigating the origin of the universe believe it is the oldest galaxy every discovered. Scientists gathering information on this matter say that the galaxy was created only 13,200 million years ago, when the universe was just 438 million years old.

"We are carefully watching an era where big changes are under way," said Garth Illingworth of the University of California at Santa Cruz, one of the investigators.

"The high speed at which the rising star changes, they tell us that if we go further back in time, we will see even more dramatic changes, closer to when the early galaxies began forming," he said.

Using the speed of light as a time reference frame, astronomers can determine how distant objects were in the past from the light they emit, so the speed of the light the galaxy emits began to travel 13,200 million years ago, just after the Big Bang occurred and created the universe. They used redshift, a Doppler light effect, to measure the distance of the galaxy; "just as a train whistle seems changing its pitch as it approaches, light also changes color when traveling through various medium densities." This galaxy has a redshift 10, which is the highest ever recorded, making the galaxy the oldest.

“Only when the James Webb Space Telescope launches later, it will reveal the early galaxy development stages with redshifts between 10 and 15."

Since the Hubble Telescope is old, being launched in the 1990's, and it outside the Earth's atmosphere, you can see only the glimmer of the galaxies, but the James Webb Space Telescope is scheduled to be launched in the year 2015 and scientists expect to get a better look at the universe.

What interested me about this article was the fact that it is about my favorite science topic, astronomy, and it is one that fascinates me. The Hubble Telescope is an invention that has contributed to the world of astronomy so much, but that is getting old and antiquated to make investigations. As technology develops we are able to look at objects further away in a more detailed manner and these developments allow us to uncover more and more about the universe and its origins. I think that it is very interesting that this galaxy was created right after the Big Bang and that it is the oldest that has yet been recorded. Before this one was found, the record for the oldest galaxy was set by another one that had redshift 8.5, when this one has redshift 10. This is a step that got us further into discovering more about the universe's origin.

Sunday, November 28, 2010

"Gene therapy prevents memory problems in mice with Alzheimer's disease"- e! Science News, November 28, 2010.

In a new study on the Alzheimer disease (AD), scientists found out that the memory problems of the patients were closely linked to the reduced levels of an enzyme called EphB2 in their memory centers of their brains. Scientists from the Gladstone Institute of Neurological Disease in San Francisco have been researching about this and they used gene therapy in order to alter the EphB2 levels in the memory centers of the mice. Scientists discovered that normalizing and improving the levels of this enzyme completely fixed the memory of the mice since reducing the levels in healthy mice gave them memory problems similar to the problems in patients with AD.

There is an important process in the body called neurotransmission, which is the communication between neurons (brain cells). In patients with AD, this communication is damaged by a protein called amyloid which is built up in abnormally high levels and it is thought to cause the disease. How these proteins disrupt neurotransmission is still unknown.

"EphB2 is a really cool molecule that acts as both a receptor and an enzyme," said Moustapha Cisse, PhD, lead author of the study. "We thought it might be involved in memory problems of AD because it is a master regulator of neurotransmission and its brain levels are decreased in the disease."

Also, increasing the levels of the EphB2 enzyme in the neurons of mice prevented neurotransmission deficits, memory problems, and behavioral abnormalities. Scientists discovered that the amyloid protein bind with this enzyme directly causing its reduction. This helps explain why in the Alzheimer's disease the levels of EphB2 are decreased.

"Based on our results, we think that blocking amyloid proteins from binding to EphB2 and enhancing EphB2 levels or functions with drugs might be of benefit in AD." said Mucke. "We are excited about these possibilities and look forward to pursuing them in future studies."

What interested me about this article was that it is about a topic that fascinates me a lot, health and medicine. Even though I do not want to be a doctor or a scientist that researches about medicine, it is a topic I like reading about. I think that gene therapy is an interesting process used to research about certain topics, in this case about the EphB2 enzyme, and to treat diseases. The Alzheimer's disease is a very dangerous one that has caused the deaths of many people, and I think it is very important to find a cure or at least a treatment for it. Many useful things have been discovered about the disease that lead to the discovery of the cure. I hope that in the near future, scientists will keep on researching about the disease and find a cure for it.

Sunday, October 31, 2010

"Trapped Mars Rover Finds Evidence of Subsurface Water" Science Daily, October, 28, 2010.

In Mars, where the NASA's Mars Exploration Rover Spirit became stuck, there is evidence of the existence of water, perhaps of snow melt, that has been trickling on a regular basis in the subsurface.

In 2004, the Rover Spirit had finished with its mission of examining Mars's surface and underground soil when the NASA decided to send it in a "bonus adventure", and during this mission, the rover got stuck in the subterranean dirt of Mars. With the failed attempts to get it out, the NASA gave up, but as the robot started researching about the soil, it found evidence of the presence of water. Perhaps the water had been in the form of snow or frost and the seepage could have happened during the planet's cyclical climate changes when it tilts farther from it axis. Insoluble materials, such as hematite, silica and gypsum, were found in the surface, while some soluble were found in deeper layers of the planet.

"The lack of exposures at the surface indicates the preferential dissolution of ferric sulfates must be a relatively recent and ongoing process since wind has been systematically stripping soil and altering landscapes in the region Spirit has been examining," said Ray Arvidson of Washington University in St. Louis, deputy principal investigator for the twin rovers Spirit and Opportunity.

When in March 22, 2010, the rover stopped communicating to NASA and both its left wheels quit working, engineers expected for it to enter a "low-power, silent hibernation mode", and the NASA began using the Deep Space Network and the Mars Odyssey orbiter to monitor the rover's position and listen if it "reawakens". Before its power levels fell too low for it to keep functioning in February 2010, researchers found soil that could be analyzed if the rover gets back to work. Since Spirit has experienced the coldest temperatures it has ever before, it is very unlikely it will survive. But if it does, it will immediately get back to work, on the studies of Mars's core.

"With insufficient solar energy during the winter, Spirit goes into a deep-sleep hibernation mode where all rover systems are turned off, including the radio and survival heaters; all available solar array energy goes into charging the batteries and keeping the mission clock running," said John Callas, project manager for Spirit and Opportunity at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

Apart from the rovers Spirit and Opportunity, there have been other NASA missions that have found evidence of water in Mars billions of years ago that could be able to carry life. Spirit is still on the search for more clues to find out about Mars's past and whether or not there was any sort of life.

I find this article very fascinating because it is about a topic I think is interesting and that really means something for humanity. It is a step for the advancement of technology that maybe in the future could develop enough to be able to transport humans to live in Mars. I think it is absolutely amazing how scientists have discovered so many things about Mars with the Spirit and Opportunity rovers, and how useful and valuable this information is. In order for technology and scientific research to advance, missions like this one are of huge importance. Maybe in a few years we will all be living in Mars!