| |
 | Posted by admin |
|
|
|
Discovered in 1996, the Canarian Spotted Lizard (Gallotia intermedia) o ‘ Tenerife giant lizards ‘ lives in the shadow of its namesake Iron and La Gomera , even more threatened. Their presence is reduced to the cliffs of the island where he fled from predators and survive in a habitat that is not theirs . In danger of extinction, this reptile ‘s future depends on a recovery plan has not yet.
Gallotia intermedia two populations on the island of Tenerife : the cliff Guaza (900 copies) and the Giants cliff in the Teno massif (between 200 and 400 copies). According to the latest census, in total are about 1,300 or 1,400 individuals . If we compare the populations of the giant lizard of Iron , which has about 300 according to the latest census, or the de la Gomera , with 100 units, the situation seems better spotted lizard . But only in appearance.
“If we consider that this lizard was on the whole island , according to fossil records there were millions of them, their current population is very low , “reports SINC Aurelio Martín , professor of Zoology at the University of La Laguna ( ULA) and one of the scientists who first described the species.
Click to continue »
| |
| Posted by admin |
|
|
|
The Kepler space telescope from NASA has detected two planets as large as Saturn transiting in front of a sun-like star observations also suggest that there might be a third planet with a size closer to the Earth. In the study , which this week published Science, involving over 40 scientists from several observatories and research centers in the U.S.
The NASA ‘s Kepler spacecraft has discovered for the first time using the transit technique ( darkening produces a planet passing in front of its star) a planetary system with more than one planet, at least two confirmed and a third possible around a sun-like star called Kepler -9. The finding is published in this week’s magazine Science.
The two confirmed planets are similar in size to Saturn’s and have been baptized with the names of Kepler and Kepler -9b -9c. A team of more than 40 U.S. researchers led by scientist Matthew Holman, Harvard- Smithsonian Center for Astrophysics in Cambridge (USA ) , analyzed the data for seven months of the space telescope to discover , the more than 156,000 stars, these two planets in transit in front of its parent star.
” The transition periods of 19.2 and 38.9 days of the two planets are increasing and decreasing respective average rates of 4 and 39 minutes per orbit, ” the researchers note in the study.
Click to continue »
| |
| Posted by admin |
|
|
|
In an attempt to solve the mysteries of the Sun, as the processes that create its activity cycle of 11 years , an international team of scientists led Rafael Garcia , a researcher Service Canarian Astrophysics CEA ( Saclay , France), has listened to the waves sound of a distant star and found one similar to the solar magnetic cycle . It is not the first time you see a cycle of activity in a star , but the first one detected sound waves, a technique that has so far only used in solar research.
Because the investigated star ( HD49933 ) is out of reach of common observation techniques to 100 light years from Earth, the researchers examined the acoustic fluctuations of the star, using a technique called stellar seismology. The star in the constellation of the Unicorn, is somewhat larger and hotter than the Sun
Scientists have detected a cycle of activities under one year compared to 11 it takes the Sun to complete theirs. This high rate of activity of the star allowed scientists to observe an almost complete cycle without waiting the 11 years required on the Sun With the use of this technique , the researchers could detect on the surface of the star -like spots those found in the sun in areas of intense magnetic activity.
The study , published this week in the journal Science, is led by Rafael Garcia , a researcher Service Canarian Astrophysics CEA ( Saclay , France ), and has enjoyed the cooperation of scientists from the Instituto de Astrofisica de Canarias (IAC ) of the National Center for Atmospheric Research USA . (NCAR ), National Center for Scientific Research French ( Paris Observatory / Meudon ) and the University of Toulouse .
Click to continue »
| |
| Posted by admin |
|
|
|
By creating two laser cavitation bubbles within the fluid that surrounds a cell, physicists perforate the membrane and it will make entering an active substance.
In a liquid, bubbles will appear where the local conditions of temperature and pressure are breaching the boiling fluid . This phenomenon , cavitation , is best known because it corrodes the propellers , turbines and any structures subjected to a violent flow . For their part, Georgy Sankin and two colleagues from Duke University in North Carolina , exploit for finely perforate a cell membrane and to bring an active substance.
The researchers used two YAG lasers (wavelength 1064 and 532 nanometers ) producing pulses of five nanoseconds , which represent about 30 micro-joules . They placed the focal points of their beams to about 40 micrometers from each other, within a microchannel containing cells ( rat mammary carcinoma ) suspended in saline tinted. The energy absorption of the first laser pulse by the liquid creates a pressure in the vicinity of the cell, giving rise to a cavitation bubble , the bubble grows to approximately 50 micrometers in diameter in approximately four microseconds before begin to collapse . At this point , the arrival of a second laser pulse creates a second bubble. The meeting and interaction between charged surfaces of surface energy of two bubbles then create a liquid microjet directed toward the cell.
Click to continue »
| |
| Posted by admin |
|
|
|
Scientists at the Research Institute for Cognitive and robotics at the University of Bielefeld (North Rhine – Westphalia) [1 ] work on reducing physical and psychological stress of astronauts. The project, lasting three years , is funded by the German Aerospace Center ( DLR ) [2 ] to 2.2 million euros .
The project’s goal is to develop artificial intelligent robots with a sense of social and large capacity interactions . The robot must learn to adapt to the mood of the astronaut and adopt strategies consistent with its interaction reactions . It will then use the best type of speech to motivate his interlocutor . It will also of course recognize people, understand speech and interpret gestures.
In parallel developments of the system , the project includes an element of empirical analysis of motivational techniques used by these coaches humans. The project will conclude with an assessment phase in real conditions .
Click to continue »
| |
| Posted by admin |
|
|
|
Dubbed E – Quickie electric vehicle developed by students from the Hochschule Karlsruhe ( Baden – Württemberg) has the appearance of a recumbent bicycle with a cell driver.
Its feature is not shipping accumulator or battery and it takes power away from power lines equipped with tracks arranged in the ground . A device installed under the car to retrieve the inductive energy and thus fuel the engine. ” The principle is not entirely new , since it is already used in a number of companies for vehicles such as cargo handling , which are however very slow and heavy . The students are now seeking to demonstrate that the use of modern materials and optimization of systems implemented could afford to build electric vehicles such fast and efficient, ” says Jurgen Walter , Faculty of Mechanical Engineering and Mechatronics . They thus set out to prove that the principle of wireless energy transfer is well suited for road transport of people.
Click to continue »
| |
| Posted by admin |
|
|
|
The planting of mangroves harms the natural circulation of water and increase sedimentation in estuaries and lagoons according to a study published recently in Sri Lanka . In December 2004 a tsunami devastated the coasts of Sri Lanka. To prevent this type of natural disaster , the authorities have launched a program to plant mangroves. This study funded by the International Union for Conservation of Nature ( IUCN) has focused on micro- tidal estuaries characterized by a tidal range less than 2 meters and on the lagoons.
The mangrove grows along the immediate coast, fixed sediment and the water rose . According Samarakoon , team director of the Integrated Resources Management Programme on Wetlands of the Central Environmental Authority of Sri Lanka , this natural process is long but in the case of human plantations has dramatically accelerated the trend , destabilizing and the coastal ecosystem.
The lagoons provide food security to many poor fishing communities . Moreover, they allow the storage of excess water during the wet season , it is absorbed by the lagoon and then discarded at low tide . Sri Lanka is characterized by a micro- tidal coastal system in which the difference between the level of water at low tide and at high tide is less than 2 meters making his ribs sensitive to the risks of siltation .
Click to continue »
| |
| Posted by admin |
|
|
|
According to a recent study by the Indian Institute of Science , in collaboration with the Carnegie Institution , Stanford University and NASA – Ames , California , increasing the number of white clouds could stop global warming .
The white clouds whose reflectivity of radiation is more important are composed of fine droplets of water , the darkest clouds are composed of larger droplets . Reduce the size of water droplets making up the clouds would thus increase the reflectivity of clouds thus allowing for lower temperatures . The goal is to increase the albedo of clouds . The results of this study were published in the journal “Climate Dynamics “under the title ” Albedo enhancement of marine clouds CounterAct to global warming : impacts on the Hydrological cycle. ”
Click to continue »
| |
| Posted by admin |
|
|
|
A team of researchers funded by the European Union has developed a new model that can estimate the necessary reductions in emissions of carbon dioxide to slow or stop global warming . The objective of this study was to simulate future climate change and CO2 emissions in the same scenario in which atmospheric CO2 concentrations would be long -term stabilized at 450 parts per million ( ppm ) . Global warming would be limited to a maximum of 2 ° C above pre-industrial level . The model has been published in the journal Climatic Change .
This work is in the ENSEMBLES project ( ” Ensemle – based Predictions of Climate Exchange and Their Impact ” ) , under the theme “Sustainable development, global change and ecosystems ‘of the Sixth Framework Programme ( FP6) [ 1] of European Union. The project supported up to 15 million euros, aims to establish a general system of predictions over time ( eg season , decade ,…) and space ( eg global , regional ,…).
According to researchers , the concentration of CO2 in the atmosphere, enhanced by the combustion of fossil fuels has increased nearly 35 % since the beginning of the industrial revolution. ” The novelty in this study is that we have incorporated into our model the carbon cycle to collect emissions data , “said Erich Roeckner of the Max Planck Institute for Meteorology in Hamburg [2 ] . The model predicts that CO2 emissions will increase by 2015 of 3 billion to 10 billion tonnes. For a long-term stabilization of atmospheric CO2 , emissions must drop nearly 56 % over the next 40 years and tend to 0 for the second half of the century . Although according to calculations, global warming between now and 2100 would not exceed the threshold of two degrees , the scientists believe it could increase the long term . ” It will take centuries for the global climate system is stabilizing , ” said Roeckner .
The team of Germany and the United States used a new method to trace the history of emissions based on calculations of CO2 concentrations in existence. Roeckner and his colleagues have taken the approach proposed by the IPCC [ 3] ( Intergovernmental Panel on Climate Change ) , a scientific body which assesses the risks of climate change caused by human activities . These models incorporate the terrestrial carbon cycle and estimated the emissions of anthropogenic CO2 compatible with a model given concentration . According to the research team , emissions depend on the proportion of anthropogenic carbon absorbed by land and oceans. They also distinguished the human-induced climate change and change internal to the climate. The model used in this study is based on a spatial grid of a frame length of 400 km and a low resolution. Were also integrated, information on land surface , oceans and the terrestrial carbon cycle and marine.
Click to continue »
| |
| Posted by admin |
|
|
|
The sea ice reaches its minimum size at the end of summer in September . Current projections indicate it will not be so reduced that in 2007 , the year in which the satellites have measured its lowest extent since such records are made. Nevertheless, physicists specialize in ice Alfred Wegener Institute for Polar and Marine Research ( AWI) are concerned about the long-term balance in the Arctic Ocean.
Some indications suggest that their mass of ice is shrinking. To prove they are currently measuring its thickness to the north and east of Greenland to the aid of the research aircraft Polar 5 . The objective of this campaign one week is to measure the export of ice from the Arctic . Between one third and half of the export of freshwater from the Arctic Ocean is in this way – a major factor in the circulation system of ocean currents.
Rüdiger Gerdes from the Alfred Wegener Institute has been trying for years to determine from where the lack of ice in the Arctic will be complete in summer . Satellites record the extent of Arctic glaciers for over thirty years. In addition to the area covered , the ice thickness is a decisive factor in determining the volume of the ice. However, the thickness can be measured only locally, for example by means of the EM- Bird , an electromagnetic measurement device that helicopters and planes towing over ice . For Rüdiger Gerdes is a very special work carried out since its usual models on his computer in his office . The campaign with the research aircraft Polar 5 leads the expedition in the Arctic for the first time. ” I am deeply interested to know the results of measurements of ice thickness “announced Professor Gerdes . “Only once we know how is the distribution of ice thicknesses , we can calculate how much fresh water is drawn through the Arctic Ocean ice.
Click to continue »
In a liquid, bubbles will appear where the local conditions of temperature and pressure are breaching the boiling fluid . This phenomenon , cavitation , is best known because it corrodes the propellers , turbines and any structures subjected to a violent flow . For their part, Georgy Sankin and two colleagues from Duke University in North Carolina , exploit for finely perforate a cell membrane and to bring an active substance.
The project’s goal is to develop artificial intelligent robots with a sense of social and large capacity interactions . The robot must learn to adapt to the mood of the astronaut and adopt strategies consistent with its interaction reactions . It will then use the best type of speech to motivate his interlocutor . It will also of course recognize people, understand speech and interpret gestures.
Some indications suggest that their mass of ice is shrinking. To prove they are currently measuring its thickness to the north and east of Greenland to the aid of the research aircraft Polar 5 . The objective of this campaign one week is to measure the export of ice from the Arctic . Between one third and half of the export of freshwater from the Arctic Ocean is in this way – a major factor in the circulation system of ocean currents.