The massif is divided into five channels that separate the Mediterranean climate zones in the north of the arid zone of the Sahara Desert to the south. Three of these channels are located in Morocco: High Atlas (covered with snow and visible in the lower left corner), the Middle Atlas (which appears as two spots of snow on the north-east of the High Atlas) and the Anti-Atlas (not visible here but located in the south-west of the High Atlas).
The High Atlas has the highest peaks in North Africa, including Mount Toubkal, which exceeds 4000 m altitude. Despite high temperatures of summer, these peaks remain snow cover for most of the year.
The Tellien Atlas and Saharan Atlas in Algeria are located (visible to the east of the Upper and Middle Atlas). The Atlas Tellien stretches along the Mediterranean coast and receives substantial rainfall which he was sheltering many fertile valleys. It extends to Tunisia (not shown here).
South AlgÃ©rien, below the Saharan Atlas (south of the Atlas Tellien) does so receives no precipitation and is part of the Sahara desert (which covers the lower part of the image).
Other elements are also visible in the image, including the Mediterranean Sea (top right) and the Atlantic Ocean (left), connected by the Straits of Gibraltar and the southern tip of Spain ( in the upper left).
This image was taken on 30 January 2009 by the camera Meris (Medium Resolution Imaging Spectrometer) Envisat working in full resolution mode, which allows to distinguish details of 300 m to the ground.
In Space with a Little HOBO
Astronauts working in spacesuits to build the Space Station may get even colder than the suit designers imagined. Measuring the effects of extremely low temperatures on astronauts was the first step in making a better space suit. (more…)
High school physics and chemistry teacher David Byrum has always been an innovator, so when online courses came to his attention, he took advantage of this new learning format. Winner of the Arizona Presidential Award for Excellence in Science Education (1988) and a National Science Teacher’s Association National Exemplar award for his chemistry course (1984), Byrum takes his work seriously. For Byrum, distance leaning was the only way to take special-interest graduate-level courses that helped him (more…)
Chemistry is a course that explores the properties of substances and the changes that substances undergo. The student will investigate the following:
Â· Atomic Structure Â· Â· Matter and Energy Â· Â· Interactions of Matter Â· Â· Properties of Solutions ” including Acids and BasesÂ· (more…)
Introduction/Purpose: I wanted to know if I could make magnetism.
Hypothesis/Questions: Is it possible to create magnetism using man-made materials? If iron-bearing metal is subject to an electric current, then magnetism will be produced.
Materials: a 6-volt battery, 10 feet of wire, a metal rod, a switch, and paper clips
Procedure: I went to Home Depot and I bought the materials. When I got home I got I got the materials out. I made the project in less than a day.
Results/Conclusion: The experiment shows that the hypothesis is true: When iron-bearing metal is subject to an electric current, then magnetism will be produced. It seems logical that the stronger the electric current, the stronger the magnetic force.
This image radar due to satellite Envisat shows the eastern part of ‘Ellesmere Island (left), the most northern Canadian islands and portions of the northwest coast of Greenland (right), the largest island the world. (more…)
Posted on 20. Jan, 2010 by in Earth Sciences
Earth in the
Welcome to Issue #1
As a long-time admirer of The Universe in the Classroom, a publication of the
Astronomical Society of the Pacific, I feel especially privileged to welcome you to this first issue of The Earth in the Classroom.
We hope to contribute to the Earth sciences in the same way that The Universe in the Classroom has contributed to astronomy. Our goal is to help you stay up-to-date on some of the most fascinating topics on Earth, under the ground and in our planet’s atmosphere.
The first thing I found out as I was running some
simulations is that if the simulation speed is too high, the program calculates the orbits extremely inaccurately as is visible in this picture (top) of the (more…)
This is not the scenario of a , but nice and although the result of a study published in the journal Physical Review Letters by a team of researchers at Imm, Cnr of Naples in collaboration with American colleagues from Berkeley Labs.
They managed to achieve a material capable of annulling the properties of light making objects invisible . The team of researchers from the Institute of Microelectronics and Microsystems of CNR (Imm-Cnr), coordinated by Vito MOCEL, conducted its study in the laboratories of the University Berkeley. The composite material artificially created, called metamaterial, has properties opposite to those we are used because of the modified structure. In the case of this study, researchers were able to confer the properties necessary to cancel the propagation of light in air and thus make the object invisible.
“Our metamaterial has been achieved by changing the nanoscale structure of silicon in which we conducted micro perforations.” Says Vito MOCEL. “We then alternated a thousand small bands of this metamaterial which exhibits characteristics opposite to those of air, with air portions of the same wavelength. When light passes through the system is air and ‘anti-air’, it’s as if he had crossed neither one nor the other two materials. ” It is as if this space, at least from the point view of the light did not exist.
“Indeed, the metamaterial has a refractive index contrast Has the air (-1) while the air is equivalent to the vacuum conventionally and has a refractive index of 1, “Vito continued MOCEL. “In this sense, the metamaterial is ‘anti-air’. By juxtaposing, anti-air and air vanish, at least as regards the propagation of light. The result is that air and anti – Air placed side by side are rendered invisible, at least for a certain wavelength. ”
For now, the prototype made to measure just 4 millimeters by 4, it is still far from creating invisibility cloaks, but the study has shown that metamaterials operate and can be used for real applications, controlling the light to a level unthinkable a few years ago.
The bacteria whether pathogenic or not, must adapt their growth to environmental changes, such as variations in temperature Researchers at CNRS (Lab Architecture reactivity and RNA), of the University of Camerino (Italy) and Dusseldorf ( Germany) have discovered that it is the structure of RNA that adapts to temperature and can thus translate the proteins necessary for the survival of bacteria. These results are published in the journal Molecular Cell, 15 January 2010.
It has already been shown that during a sudden drop in temperature, the process of transcription (producing RNA from DNA) and translation (protein production from mRNA) are strongly affected. However, low temperature, protein family CSpA (cold shock protein) are more numerous. These proteins called “cold adaptation” are from the translation of a dozen genes. These are protein “chaperone” DNA and RNA, they bind to nucleic acids and thus facilitate the most fundamental processes (transcription, translation, degradation of RNA, assembly of ribosomes …).
Researchers Laboratory Architecture and responsiveness of the NRAs (CNRS), University of Camerino (Italy) and the University of DÃ¼sseldorf (Germany) showed that the structure of the messenger RNA (mRNA) that encodes the major protein response to cold, CSPA, was able to “feel” temperature. They noted that the nascent mRNA adopts a structure that is unstable and transient high temperature, but is stabilized at low temperature. This structure favors translation at low temperature, revealing the molecular mechanism by which the protein CSpA is produced in large quantities in response to stress.
This study highlights a novel molecular mechanism where the mRNA structure adapts itself to the temperature. The changing structure of the mRNA without the intervention of proteins can be regarded as a primitive mechanism of regulation The mRNA then carries out a key function in gene regulation, particularly in adaptive processes. The discovery of these new regulatory macromolecules opens the way for new strategies to inhibit bacterial growth.