Life originated on the Earth more than 3.5 billion years ago. However, the scientists are still disputing over the possible sources of the life origin. The matter is that life on our planet evolved from the molecular level to the level of bacteria organisms within 0.5 - 1 billion years, this period being very short for such an important evolutionary step. The researchers are still racking the brains over this mystery. One of the popular hypothesis asserts that some germs of life have been brought to the Earth from space. But what exactly could have been brought from space and how could the germs have originated in space?
E.A. Kuzicheva and N.B.Gontareva, research assistants from the Institute of Cytology, Russian Academy of Sciences, have confirmed a possibility of abiogenous synthesis of complex organic compounds (monomeric units of nucleic acids) on the surface of comets, asteroids, meteorites and space dust particles in the outer space. Therefore, it is possible that the above monomeric units of nucleic acids could have got to the Earth and thus could have significantly reduced the time period of the evolution process. On the surface of space bodies the scientists have found all kinds of various organic molecules (amino acids, organic acids, sugars etc.) and the components required for their synthesis. Obviously, it is there that organic substances are being synthesised, but the researchers can not be sure of this fact, until the experiments confirm their assumptions. The scientists from St. Petersburg reproduced synthesis of one of the DNA components - 5`-adenosine monophosphate (5`-AMP) under the conditions specially designed to simulate the space environment. In order to synthesise 5`-AMP it is required to combine adenosine and inorganic phosphate. On the Earth the reaction goes in the solution, but there are no solvents whatsoever in space, therefore the researchers dried them in the air and got a pellicle. Synthesis requires energy. The major source of energy in the outer space both at present and in the prebiotic period of the Earth history has been the solar ultraviolet radiation of different wavelengths. Therefore, the pellicles were irradiated by a powerful ultraviolet lamp. Naturally, the synthesis was carried out in vacuum, and the researchers used the lunar soil, delivered to the Earth by the `Moon-16` station from the Sea of Abundance, as a model of the comet, meteorite, interplanetary or cosmic dust. The soil represented basaltic dust of the dark-grey colour, the diameter of its particles being less than 0.2 millimetres.
After 7-9 hours of ultraviolet irradiation of the dry pellicles the scientists acquired several compounds, mainly 5`-AMP, one of the DNA/RNA monomers. The energy of radiation does not promote synthesis alone, it also facilitates decomposition of the initial and newly-synthesised compounds, the more powerful the radiation is, the more extensively the decomposition goes. However, the lunar soil provided some protection. It has appeared that a small pinch of the lunar soil protects organic substances from the destructive ultraviolet impact - the lunar soil helps to increase the 5`-AMP yield by 2.7 times.
Natalia Reznik | alphagalileo
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At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
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Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
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