Sunday, July 25, 2010

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FROM THE Geosmin AND THE "SMELL OF WET LAND "



The geosmin, which means in Greek " aroma land "is a chemical produced by the bacterium Streptomyces coelicolor , some cyanobacteria that are on the ground, and that is perceived when the land is wet, for example, when it rains. Some filamentous fungi Penicillium expansum ocmo also produce geosomina.

The Streptomyces microorganism is a major in the field of medicine modern and current, given the possibility to obtain from he antibiotics such as tetracycline, erythromycin, rifampicin or kanamycin antifungal such as nystatin and antitumor agents, anthelmintics and immune suppressants , among others.

genome research has identified the gene producing the characteristic aroma, which when manipulated experimentally removed from the bactaria, was lost.

This molecule is very important for vertebrate animals that live in the desert mainly for camelids , who perceiving the smell can be assured that they will find in a short time the liquid element.

The geosmin is also responsible for some undesirable aromas in wine. When the grapes have been attacked by one of the geosmin-producing filamentous fungi, the wine may also have earthy aromas characteristic of this molecule.

more information click the following link:
http://alkaidedicionesciencia.blogspot.com/2010/04/geosmina-y-el-olor-tierrageosmin-and.html

Saturday, July 24, 2010

Little Growths Inside My Mouth

ROSETTA DOES Graphene DISCOVER THE BEAUTY OF THE DEEP SPACE 10 STEPS


The Rosetta spacecraft, European Space Agency (ESA European Space Agency or, in English) has sent close-up photographs of asteroid Lutetia, a relic cratered coming the birth of the solar system. The images, which reveal a small universe of strange and captivating beauty, remain enthusiastic scientists.

"I've never seen anything like this" , said Claudia Alexander, U.S. researcher Rosetta project. "It looks as if it were detached from the parent asteroid, is all angles and plains, ancient impacts superimposed on the most recent, covered by some kind of dust."

In particular, Alexander is intrigued by the giant crack that is located on the side of the asteroid.

"My first thought was that it is the remnant of a huge shock occurred at some time in an already distant past, "says Alexander." The corners are shallow rather than sharp and deep, as in the case of a newly formed crater. Undoubtedly, it will be many more analysis of this feature over the coming weeks. "

And then there is the mysterious suspect that at some point in time the rocks rolled down on Lutetia saw.

" If that's what we're actually seeing, the question is: what was it that made it roll? Perhaps the asteroid rotated upward, rotated down, or experience any irregularities in its orbit. Not yet clear that the asteroid would be subject to the forces capable of causing these things. That is another issue that must be studied. "




" Right now we have more questions than answers, "continues Alexander . " At this point, we can only speculate about what we are seeing in Photos.

For many years, the asteroid Lutetia has been the target of interest among astronomers. It is one of the largest asteroids in the solar system and has a strange spectrum of reflected light that does not look anything like a another asteroid. As the Rosetta spacecraft will pass close to him on his path toward primary target, comet 67P/Churyumov-Gerasimenko in 2014, mission planners could not pass up the opportunity.

Now that Alexander has seen the pictures, you can not help but wonder how it would ride on the asteroid's surface.

" For the astronauts would make it difficult to walk on Lutetia, there is probably much lower gravity on the Moon" she says. "Moreover, the surface regolith is very dusty, so that astronauts would sink about 2.5 centimeters on each step we took."

The MIRO (Microwave Instrument for the Rosetta Orbiter Microwave Instrument or for the Rosetta Orbiter), NASA, will help determine if the layers of the surface is dusty or rocky. As the researchers analyzed data provided by the other instruments of the Rosetta probe, may determine the mass and density of Lutetia, revealing much more information on the composition of the asteroid and helping to solve the riddle of their origin.

Is Lutetia planetary fragment of 130 km that broke off for billions of years? Or is it one of the original planetary building blocks, which astronomers call "planetesimals," which has remained in its initial state because he was never caught by any planet during the years of solar system formation?

As scientists begin to answer these questions, using data provided by the Rosetta probe, gain new insights about the origin and history of asteroids, and also learn much more about the evolution of the solar system itself. The content of an asteroid can reveal something about the conditions and composition of the solar nebula where the asteroid formed.

"Rosetta took measurements using 17 different instruments," says Rita Schulz, a research project of the ESA Rosetta mission. "Once you have analyzed all data, Lutetia will have become one of the known asteroids.

"These spectacular images," says , "are just the beginning."

Source: NASA

Sunday, July 11, 2010

How To Materbate Home Alone

MOST RELEVANT EVOLUTIONARY

The evolution of species throughout its history has allowed the emergence of impressive qualities of living things. In this post I would like to review that I believe are the 10 most significant changes that have occurred in the history of life on Earth since it first appeared living beings. Obviously these steps were all very gradual and hard to pin it down in "one step". The list is arranged in chronological order onset based on replicating the first people whose specific characteristics we can only speculate now:

1-Fidelity in DNA copy of the current
Bacteria make a mistake in copying the DNA approximately every 10E10 generations. The ratio between mutations and fidelity allows adjustments while limiting errors quickly accumulate large that would wipe out the species. The main architect of this evolutionary marvel called DNA polymerase alone is able to copy accurately several thousand DNA bases before making a mistake. The more advanced versions that appeared later in the evolution of eukaryotes also have review mechanisms to minimize mistakes. Your need for life is such that there are creatures that lack this mechanism. Only a few viruses like HIV which in turn use the cellular machinery perfect.

2-The scourge

De wait until the food arrives, go for it. This one change led to major changes in the flagellum. Although previously developed bacteria tiny hairs (cilia) that allowed some movement it is true that you were totally subject to the forces that govern Brownian motion: Imagine that you are in a pool full of marbles that are propelled at high speed in all directions . The scourge also represented an improvement in the ability to colonize new and distant environments or to escape adverse circunstanrcias. You can see a video on the evolution of the flagellum is postulated here that appeared from an organelle for the subject.

3-The photoreceptor
And there was light. The ability to recognize the light initially supposed access to food (the synthesis of many organic compounds is catalyzed by light) and a guide for the movement (defined above and below). However, this small step would sow the seeds for two mechanisms of great relevance future: photosynthesis and vision. The photoreceptors are based on pigments capable of excited with the light and transmit the excited state to a protein.

4- Photosynthesis
Who needs food when you produce it? This is perhaps the most impressive evolutionary leap: the ability to produce organic compounds from inorganic, much more abundant. These reactions require high-energy that living things get the heat, degradation of other organic / inorganic or light. Photosynthesis could not be possible without the photoreceptors also probably co-evolved with the improvement of the flagellum. None of these "house of cards" would have endured without the copying-fidelity DNA.

5-Krebs cycle and oxidative respiration
Photosynthesis brought a new era of problems or opportunities as you look. The main waste of photosynthesis is oxygen. A molecule that now seems innocuous but when it appeared it was like living in a sea of \u200b\u200barsenic. Oxygen has the capacity to oxidize DNA and proteins and interfered in many of the reactions necessary for the bacteria at the time. The emergence of atmospheric oxygen was probably a quick process that just one stroke with most species. Some species (including oxygen production) developed mechanisms to inactivate oxygen, these mechanisms are the use of electrons and protons react with oxygen to produce water. Interestingly electrons can be obtained as waste products of metabolism of organic compounds. The sophistication of the metabolism of sugars called the Krebs cycle with a complex electron transport system possible to maximize the power of organic compounds.

6-The eukaryotic cell
The complexity of the emergence of life is the only fact comparable to the emergence of the eukaryotic cell. It has been speculated that eukaryotes from the bacterial symbiosis of various types, hypothesis is more powerful genetic analysis. In any case the appearance of cells with defined nucleus and organelles is a big black box. One of the most interesting evolutionary processes that remain to be deciphered. The breakthrough of the eukaryotic cell can be described by something as simple as compartmentalization. Everything in his corner. Many of the cellular chemical reactions require a very specific environment incompatible with other reactions.

7-cell specialization
The favorite son. One cell divides into two but it is the same in each daughter cell, one containing more waste than any other, different protein concentration or lacks any component. These may have been the history of cell specialization. Currently occurs in bacteria, yeast or some unicellular algae and in some cases, live in colonies, where some individuals specialize in certain functions depending on their location within the colony. Specialization means greater efficiency. From there to cells such as neurons or white blood cells would be still a long way.

8-
sexual reproduction would we be without sex! It has been suggested that sexual reproduction allows rapid adaptation of species to quickly eliminate harmful mutations and spread the benefit. His appearance could be related to viruses and other parasites or as a byproduct of the strategy of doubling the genome to reduce the effects of mutations. In any case, sexually reproducing life forms have diversified and acquired a complexity that no asexual can be overcome.

9-embryonic development
"Nothing that happens in life you will mark you as much as gastrulation. The instructions to form a body in a gradual and orderly accounted jump a world of jellyfish and worms today. Instructions are grouped into blocks or genetic packages that allow greater adaptability. One way to highlight in embryonic development is gastrulation, which involves the invagination of a layer of cells of the embryo. So, at first glance not seem so important but its appearance marked specialization in 3D, as in most animals as us versus 2D specialization that occurs in worms.

10-The brain and nervous system
Long before the appearance of the nervous system cells communicate only through contacts with neighboring cell and the emission of signals such as hormones. In my opinion, the jump is not so much in the formation of a network to deliver faster signals but in a centralization of signals in the long run would be the appearance of the brain. The study of neural networks has advanced considerably in recent years thanks to studies in several animal models, especially in the worm C. elegans, we are aware of the network formed by its 302 neurons.


Source: TALL & CUTE