Archive for the ‘Biology’ Category
An investigation by the National Research Council (CSIC) has discovered a hormone that coordinates the growth of tissues and organs in the fruit fly (Drosophila melanogaster). The finding is published in the journal Science.
According to the study, Drosophila Insulin-Like Peptide 8 (DILP8) is secreted by peripheral tissues during the development process that brings the body and the coordinated growth between organs and tissues. Likewise, this hormone is also secreted in response to damaged tissues, as it inhibits the production of hormones such as ecdysone, delaying sexual maturity until the growth process has completed successfully.
The researcher at the Neurosciences Institute (a joint CSIC and University Miguel Hernandez of Elche) Maria Dominguez, who led the study, explains: “all organisms, including humans, so mysterious coordinate the growth of various organs and parts of the body, keeping the ratio between them and an almost perfect bilateral symmetry.” According to Dominguez, “so far, had not found any sign that would control this process, but its accuracy suggested the existence of some form of communication between them”. Read the rest of this entry »
The researcher Diego Miranda Saavedra works in the Immunology Frontier Research Center of Osaka University (Japan) studying inflammation, a very common response of the organism against various diseases. Its aim is to investigate the mechanisms that explain how the inflammation subsides or “quenched”.
The Laboratory for Genomics and Bioinformatics where you work combines experiments with computational analysis to study important problems in the field of Immunology and precisely one of the most important is how “turns off” inflammation. “Inflammation can be initiated in many ways, usually by a bacterial infection, but it really is not much studied how it goes”, he says.
However, it is a fundamental mechanism, because “a persistent inflammation is associated with many diseases, including atherosclerosis, neurodegenerative diseases, rheumatoid arthritis, diabetes or asthma”, says expert. That is not the cause of these diseases, “but a lot worse”. Read the rest of this entry »
It is often said that trees and plants in general, are the lungs of the planet, but a new discovery can now say that they can also play an important role in the electrification of the atmosphere.It has long been suspected that there was a link between trees and electricity. Now, with that finding, seems to have discovered the mechanism that finally allows the striking activity of the trees.
The team of Rohan Jayaratne and Xuan Ling, the International Laboratory for Air Quality and Health (ILAQH), led by Professor Lidia Morawska of Queensland University of Technology, Australia, conducted experiments in six locations Brisbane area. The researchers found that concentrations of positive and negative ions in the air were two times higher in the hardwood forest areas in turf areas, such as parks.
The explanation given to the phenomenon is as follows:
Under normal conditions as those present in the sites examined for the new study, the natural ions that are in the air are created primarily by ionization through two basic processes: radiation from radon, a gas present in very small amounts in the air and cosmic radiation from space. Read the rest of this entry »
We have discovered a new mechanism of memory in the nervous system to help prevent complete exhaustion from intense physical activity. This is the first time detected this form of short-term memory in a vertebrate animal.
Many know the feeling when our tired muscles ask us to stop exercising. However, there is increasing evidence that our brain contributes to this fatigue and tells us to stop doing an activity long before the whole system is completely exhausted, to thereby always maintain a reserve for emergencies. The need to change speed endurance is important for all animals, as there are many situations in which resistance can be us more useful than speed, and if we waste forces in a very fast race may be unable to meet post-conflict situations.
The discovery of this particular form of memory in a vertebrate was made by the team of Dr. Hong-Yan Zhang and Professor Keith Sillar, both from the University of St. Andrews, United Kingdom, to study how certain networks nerves control movement in Xenopus tadpoles type. Read the rest of this entry »
Although the giant squid, by its large size, with bodies that may also deserve the label of “giant”, the eyes so striking beyond the dimensions that would be expected to have, and this has long intrigued the scientific community. Evolutionarily, it would make sense for an animal as large eyes develop without a good practical reason.
Now a new study seems to have found the explanation for this enigma. In principle, to see in an environment with low light, like the deep sea, have big eyes is better than having small eyes, simply because the large capture more light. However, the optical properties of water severely restrict the maximum distance that can distinguish things. Read the rest of this entry »
The origin of polar bears (Ursus maritimus) as independent species occurred about 600,000 years, as revealed by an international investigation in which participated the CSIC. Their evolutionary history is, therefore, five times older than previously thought, as reflected in the article that graces the cover of the journal Science.
Previous articles were found similarities in mitochondrial DNA (from the mother) between polar bears and brown bears (Ursus arctos). As a result, it was assumed that Arctic species belonged to a lineage split from their brown cousins made between 166,000 and 111,000 years and had experienced a rapid adaptation to polar conditions.
The new research is based on the analysis of nuclear DNA from 19 samples of polar bear, brown bear 18 aircraft and seven copies of black bear (Ursus americanus). The differences detected between the genomes indicate that the polar and brown species diverged from a common ancestor about 600,000 years. Read the rest of this entry »
New research shows how the ability to detect light could evolve before the appearance of the first eye. The research is based on the stinging mechanism of the Hydra magnipapillata, a small polyp of freshwater has no eyes. The hydra, which belong to the phylum Cnidaria in which include sea anemones, corals and jellyfish, are basically mouths surrounded by tentacles armed with stinging cells.
The team of David Plachetzki (now at the University of California at Davis), Caitlin Fong and Todd Oakley, of the Department of ecology, evolution and marine biology at the University of California at Santa Barbara, found a simple nervous system associated with stinging cells with rudimentary nerve cells that sense light.
Nerve cells express a set of genes that includes the opsin proteins are sensitive to light. These components are basically the same as those of the light-sensing machinery in animals with eyes, including the Human Being. Read the rest of this entry »
The amazing results of a careful analysis reveals that, even before many of the major parts of ribosome (cell structures that are assembled proteins) were recruited for the job of protein synthesis, protein existed in the stage of life , and it interacted with the RNA.
This finding challenges a widely accepted hypothesis on the evolution of primitive life on Earth. In the chemistry of our planet, pair of nucleic acids (DNA and RNA) is long molecules carry the genetic code, and all agencies provide a mechanism to play properly, and to build the many proteins that are fundamental to living systems.
However, it is unclear how it started this “monopoly”. The DNA and RNA molecules are suitable for life and now it works. But in the prebiotic chaos of the past distant from Earth, chemical machinery of life transition due require precursor pieces that easier form randomly, preserved, and lead towards the others. Read the rest of this entry »
Bacteria have developed different systems to secrete proteins into the surrounding fluid or into other cells. Some bacteria, for example, have external structures comparable to a syringe, which can be nailed in other cells to inject them to certain proteins.
Another system, called type VI secretion system, is present at about one quarter of all bacteria that have two membranes. Despite being common, scientists have not determined how it works. Now a team of specialists has figured out how exactly the system structure of type VI secretion and has concluded that it acts as a kind of spring crossbow that shoots poison darts.
The nanoarms, spanning a distance no greater than about 80 atoms in a row, is a tube shrinks rapidly firing a dart or internal knife through the cell membranes, to the surrounding medium, and possibly inwardly of another cell. The tube can then be disassembled and reassembled elsewhere in the cell, ready to fire another dart molecular. Read the rest of this entry »
Besides photosynthesis, plant cell wall is a feature that most distinguishes plants against animals. A structural molecule, cellulose, it is necessary to make these walls. Cellulose is synthesized in a semicrystalline state is vital for its role in the functioning of the cell wall, but little is known about the mechanisms controlling its crystallinity.
New research, conducted by experts from Argentina, U.S. and Canada, has yielded key information about this process and find a way to reduce the crystallinity of cellulose, which is a major obstacle in developing commercially viable processes develop biofuels.
Generally, the individual sugar chains comprising the cellulose intertwine creating a semicrystalline fiber. This structure gives crystalline cellulose essential mechanical properties such as adequate rigidity and a high resistance to structural tensions. Read the rest of this entry »