Immagine
 Trilingual World Observatory: italiano, english, românã. GLOBAL NEWS & more... di Redazione
   
 
\\ Home Page : Storico : en - Science and Society (invert the order)
Di seguito gli interventi pubblicati in questa sezione, in ordine cronologico.
 
 

The 8,400 panel, 2 megawatt solar array spans the space of six soccer fields, and it was finished in time to start feeding power to the grid before the clock strikes 2012. To prove the solar array’s everyday worth, the airport has installed a real time statistics ticker in the airport lobby so passengers can see how much energy it is creating and how much carbon dioxide is being diverted from the atmosphere.

Construction on the array was completed in just eight weeks — it was started this past October — and was built through a partnership between Düsseldorf International and a subsidiary of the city’s public services, Grünwerke GmbH. “A PV plant of this magnitude within the safety parameters of one of the country’s largest passenger airports reflects a new way of thinking about renewable energies, and we welcome it as another contribution of our city in the service of environment,” said Dirk Elbers, Düsseldorf’s mayor.

The solar array is the largest ground-mounted system located within the security zone of a German Airport but it isn’t the Düsseldorf Airport’s first foray into renewable energy. “Solar energy is not the only source of renewable energy at DUS. We also employ combined heat and power technology in a block heating station, and keep carbon dioxide emissions even lower this way,” noted Christoph Blume, CEO of DUS. The new solar array will create enough power to run 600 four person homes every year.

Source: Inhabitat - via ZeitNews.org

 

For NASA researchers, pixels are much more – they are precious data that help us understand where we came from, where we've been, and where we're going.

At NASA's Ames Research Center, Moffett Field, Calif., computer scientists have made a giant leap forward to pull as much information from imperfect static images as possible. With their advancement in image processing algorithms, the legacy data from the Apollo Metric Camera onboard Apollo 15, 16 and 17 can be transformed into an informative and immersive 3D mosaic map of a large and scientifically interesting part of the moon.

Mosaic of the near side of the moon as taken by the Clementine star trackers. The images were taken on March 15, 1994. Credit: NASA

The "Apollo Zone" Digital Image Mosaic (DIM) and Digital Terrain Model (DTM) maps cover about 18 percent of the lunar surface at a resolution of 98 feet (30 meters) per pixel. The maps are the result of three years of work by the Intelligent Robotics Group (IRG) at NASA Ames, and are available to view through the NASA Lunar Mapping and Modeling Portal (LMMP) and Google Moon feature in Google Earth.

"The main challenge of the Apollo Zone project was that we had very old data – scans, not captured in digital format," said Ara Nefian, a senior scientist with the IRG and Carnegie Mellon University-Silicon Valley. "They were taken with the technology we had over 40 years ago with imprecise camera positions, orientations and exposure time by today’s standards."


Left: A normal one-camera image of the lunar surface. Right: A composite Apollo Zone image showing the best details from multiple photographs. Credit: NASA/Google Earth

The researchers overcame the challenge by developing new computer vision algorithms to automatically generate the 2D and 3D maps. Algorithms are sets of computer code that create a procedure for how to handle certain set processes. For example, part of the 2D imaging algorithms align many images taken from various positions with various exposure times into one seamless image mosaic. In the mosaic, areas in shadows, which show up as patches of dark or black pixels are automatically replaced by lighter gray pixels. These show more well-lit detail from other images of the same area to create a more detailed map.

"The key innovation that we made was to create a fully automatic image mosaicking and terrain modeling software system for orbital imagery," said Terry Fong, director of IRG. "We have since released this software in several open-source libraries including Ames Stereo Pipeline, Neo-Geography Toolkit and NASA Vision Workbench."

Lunar imagery of varying coverage and resolution has been released for general use for some time. In 2009, the IRG helped Google develop "Moon in Google Earth", an interactive, 3D atlas of the moon. With "Moon in Google Earth", users can explore a virtual moonscape, including imagery captured by the Apollo, Clementine and Lunar Orbiter missions.

The Apollo Zone project uses imagery recently scanned at NASA's Johnson Space Center in Houston, Texas, by a team from Arizona State University. The source images themselves are large – 20,000 pixels by 20,000 pixels, and the IRG aligned and processed more than 4,000 of them. To process the maps, they used Ames' Pleiades supercomputer.

The initial goal of the project was to build large-scale image mosaics and terrain maps to support future lunar exploration. However, the project's progress will have long-lasting technological impacts on many targets of future exploration.

"The algorithms are very complex, so they don't yet necessarily apply to things like real time robotics, but they are extremely precise and accurate," said Nefian. "It's a robust technological solution to deal with insufficient data, and qualities like this make it superb for future exploration, such as a reconnaissance or mapping mission to a Near Earth Object."


The color on this map represents the terrain elevation in the Apollo Zone mapped area. Credit: NASA/Google Earth

Near Earth Objects, or "NEOs" are comets and asteroids that have been attracted by the gravity of nearby planets into orbits in Earth's neighborhood. NEOs are often small and irregular, which makes their paths hard to predict. With these algorithms, even imperfect imagery of a NEO could be transformed into detailed 3D maps to help researchers better understand the shape of it, and how it might travel while in our neighborhood.

In the future, the team plans to expand the use of their algorithms to include imagery taken at angles, rather than just straight down at the surface. A technique called photoclinometry – or "shape from shading" – allows 3D terrain to be reconstructed from a single 2D image by comparing how surfaces sloping toward the sun appear brighter than areas that slope away from it. Also, the team will study imagery not just as pictures, but as physical models that give information about all the factors affect how the final image is depicted.

"As NASA continues to build technologies that will enable future robotic and human exploration, our researchers are looking for new and clever ways to get more out of the data we capture," said Victoria Friedensen, Joint Robotic Precursor Activities manager of the Human Exploration Operations Mission Directorate at NASA Headquarters. "This technology is going to have great benefit for us as we take the next steps."

More information: http://lmmp.nasa.gov/

Source: JPL/NASA - via ZeitNews.org

 

Now a Danish chemist has pioneered a novel way to battle multidrug resistant bacteria. By tweaking a well known psychoactive drug he revitalizes worn-out drugs like sulpha and penicillin.

Chemist Jorn Bolstad Christensen of the University of Copenhagen has just patented the use of schizophrenia medication Thioridazin in boosting the effect of antibiotics. Christensen is an associate professor at the Department of Chemistry, University of Copenhagen, and in the lab he started investigating how the schizophrenia drug might bother bacteria but not humans.

"Thioridazin blocks the capacity of bacteria to cleanse themselves of antibiotics. We knew that before starting. But I wanted to remove the action of the drug in the brain so that mortally ill tuberculosis patients wouldn't have to contend with psychoactive effects as a part of their cure," explains Christensen, who none the less had to come to terms with a much bigger threat as well.

Bacteria such as those responsible for tuberculosis, staphylococcus and enterococcus get rid of antibiotics using their so called efflux-pump. A mechanism which simply pumps the active substance out of the cell before it has an opportunity to do harm. A substance which blocks the pump should ensure that any antibiotic stays inside the bacteria long enough to kill it. There's just one tiny problem. Human cells have efflux pumps as well. And we wouldn't want these blocked.

"The task was to find a substance that will kill bacteria, but not the patients taking the cure. Thioridazin was a good candidate because it's been in use for decades. We could be pretty certain that it wouldn't have any serious side effects," says professor Christensen, who predicts testing the new drug in humans within just a year, as it's already been approved for other medical uses.

Though the risk of blocking the efflux pump of human cells appeared minimal Professor Christensen still needed to minimize the psychoactive effects of the drug. This was where his chemical expertise became indispensable. Chemically Thioridazin consists of two half molecules which are perfect mirror images. One of these mirror- or isomeric forms affects the brain less than the other, so the question was whether bacteria would know the difference.

Doctors and researchers Jette Kristiansen and Oliver Hendricks of Southern University Denmark who are co-holders of the patent have conducted microbiological trials proving that the efflux pump of bacteria stayed blocked regardless of which isomer was used. These results open up a brand new method for combating problems of multidrug resistance.

Source: University of Copenhagen

 

A research team at the Max Planck Institute of Biophysics in Frankfurt am Main has developed a molecular light switch that makes it possible to control cells more accurately than ever before. The combination switch consists of two different light-sensitive membrane proteins – one for on, the other for off. The method used by the scientists to connect the two components can be used with different protein variants, making it highly versatile.

Optogenetics is a new field of research that aims to control cells using light. To this end, scientists avail of light-sensitive proteins that occur naturally in the cell walls of certain algae and bacteria. They introduce genes with the building instructions for these membrane proteins into the DNA of target cells. Depending on which proteins they use, they can fit cells with on and off switches that react to light of different wavelengths.

Molecular combination switch: two light-sensitive membrane proteins - here red and purple - are linked via a connecting piece (green) and anchored into the cell wall (left). When the cell is illuminated with blue light, it allows positively charged ions in. Orange light has the opposite effect, allowing negatively charged ions into the cell. The cell is activated or deactivated, respectively (right). © MPI of Biophysics

For accurate control, it is important that the cell function can be switched off and on equally well. This was exactly the problem until now: when the genes are introduced separately, the cell produces different numbers of copies of each protein and one type ends up dominating.

A group of scientists headed by Ernst Bamberg at the Max Planck Institute of Biophysics has now developed a solution that is both elegant and versatile: they have located the genes for the on and off proteins on the same portion of DNA, along with an additional gene containing the assembly instructions for a connection piece. This interposed protein links the two switch proteins and anchors them firmly in the cell membrane. “In this way, we can ensure that the on and off switches are built into the cell wall side by side, and always in a ratio of 1:1. This allows us to control the cell with great accuracy”, explains Ernst Bamberg.

The combination light switch conceived by the researchers consists of the membrane proteins channelrhodopsin-2 and halorhodopsin. Channelrhodopsin-2 originally comes from the single-celled green alga Chlamydomonas reinhardtii. It reacts to blue light by making the cell wall permeable to positively charged ions. The resulting influx of ions triggers a nerve impulse that activates the cell. Halorhodopsin, isolated by scientists from the bacterium Natromonas pharaonis, has the opposite effect: when the cell is illuminated with orange light, it allows negatively charged ions in, suppressing nerve impulses.

Since channelrhodopsin-2 and halorhodopsin react to light of different wavelengths, together they comprise a useful tool for switching cells on and off at will. The scientists have shown that the method they used to connect the two molecules is also suitable for use with other proteins. “By linking different proteins as required, we will be able to control cells with much greater accuracy in future”, affirms Bamberg.

Source: Max-Planck-Gesellschaft - via ZeitNews.org

 

A team of Weizmann Institute scientists has turned the tables on an autoimmune disease. In such diseases, including Crohn's and rheumatoid arthritis, the immune system mistakenly attacks the body's tissues. But the scientists managed to trick the immune systems of mice into targeting one of the body's players in autoimmune processes, an enzyme known as MMP9. The results of their research appear today in Nature Medicine.

Prof. Irit Sagi of the Biological Regulation Department and her research group have spent years looking for ways to home in on and block members of the matrix metalloproteinase (MMP) enzyme family. These proteins cut through such support materials in our bodies as collagen, which makes them crucial for cellular mobilization, proliferation and wound healing, among other things. But when some members of the family, especially MMP9, get out of control, they can aid and abet autoimmune disease and cancer metastasis. Blocking these proteins might lead to effective treatments for a number of diseases.

Originally, Sagi and others had designed synthetic drug molecules to directly target MMPs. But these drugs proved to be fairly crude tools that had extremely severe side effects. The body normally produces its own MMP inhibitors, known as TIMPs, as part of the tight regulation program that keeps these enzymes in line. As opposed to the synthetic drugs, these work in a highly selective manner. An arm on each TIMP is precisely constructed to reach into a cleft in the enzyme that shelters the active bit – a metal zinc ion surrounded by three histidine peptides – closing it off like a snug cork. 'Unfortunately,' says Sagi, 'it is quite difficult to reproduce this precision synthetically.'

Dr. Netta Sela-Passwell began working on an alternative approach as an M.Sc. student in Sagi's lab, and continued on through her Ph.D. research. She and Sagi decided that, rather than attempting to design a synthetic molecule to directly attack MMPs, they would try trick the immune system to create natural antibodies that target MMP-9 through immunization. Just as immunization with a killed virus induces the immune system to create antibodies that then attack live viruses, an MMP immunization would trick the body into creating antibodies that block the enzyme at its active site.

Together with Prof. Abraham Shanzer of the Organic Chemistry Department, they created an artificial version of the metal zinc-histidine complex at the heart of the MMP9 active site. They then injected these small, synthetic molecules into mice and afterward checked the mice's blood for signs of immune activity against the MMPs. The antibodies they found, which they dubbed 'metallobodies,' were similar but not identical to TIMPS, and a detailed analysis of their atomic structure suggested they work in a similar way – reaching into the enzyme's cleft and blocking the active site. The metallobodies were selective for just two members of the MMP family – MMP2 and 9 – and they bound tightly to both the mouse versions of these enzymes and the human ones.

As they hoped, when they had induced an inflammatory condition that mimics Crohn's disease in mice, the symptoms were prevented when mice were treated with metallobodies. 'We are excited not only by the potential of this method to treat Crohn's,' says Sagi, but by the potential of using this approach to explore novel treatments for many other diseases.' Yeda, the technology transfer arm of the Weizmann Institute has applied for a patent for the synthetic immunization molecules as well as the generated metallobodies.

Source: Weizmann Institute of Science - via ZeitNews.org

 

While a simple tablet, taken by the patient with a sip of water, may be the easiest way to administer a drug, this may not always be the most suitable. Some drugs are subjected to degradation by the body, while others, such as cancer medications, can be more effective if they are delivered directly to the diseased tissue site. Such a delivery could improve the effectiveness of the treatment and potentially reduce side effects.

Yiyan Yang and Jeremy Tan from the A*STAR Institute of Bioengineering and Nanotechnology, working in collaboration with researchers from the IBM Almaden Research Center and Stanford University in the USA, have reported the preparation of biodegradable, water-soluble polymers that can be loaded with the cancer drug Paclitaxel and injected directly into tumor tissues. Warming to body temperature causes the release of the therapeutic cargo with the system showing improvement in killing cancer cells over treatment with the drug alone.

Rather than being made from repeating units of a single monomer, the polymers described are a type of block copolymer—a polymer with one block that contains hydrophilic and hydrophobic groups and another block that contains hydrophobic groups. It is through the careful balance between these groups that the temperature-responsive property of the polymer is achieved.

To make the copolymers, Yang and co-workers used the process of living polymerization, which allows the polymer chains to keep growing until the supply of monomer is exhausted. When more monomers are added, polymerization will restart. The approach allows polymers with different sized blocks of hydrophilic and hydrophobic groups to be built easily to optimize the properties. It also results in polymers with a narrow distribution of molecular weights—an important factor in producing polymers with consistent properties throughout a sample.

Thermoresponsive polymers have been studied before, with one of the most intensively investigated being poly(N-isopropylacrylamide) (PNIPAAm), which was first synthesized in the 1950s. The critical difference in the new polymers described by Yang and co-workers is that they are both non-toxic and biodegradable. “After these polymers performed their task of delivering their important cargos, they should break down and be excreted without significant additional side effects,” says Yang. “We are now planning to further work with the IBM Almaden Research Center and other industrial partners to evaluate the in vivo toxicity and efficacy of this system for the delivery of therapeutics.”

Source: Agency for Science, Technology and Research - via ZeitNews.org

 

Highly excited Rydberg atoms can be 1,000 times larger than their ground state counterparts. Nearly ionized, they cling to faraway electrons almost beyond their reach. Trapping them efficiently is an important step in realizing their potential, the researchers say.

Giant Rydberg atoms become trapped in wells of laser light in a new highly efficient trap developed by University of Michigan physicists. They liken it to an egg carton. Image: Sarah Anderson

Here's how they did it:

"Our optical lattice is made from a pair of counter-propagating laser beams and forms a series of wells that can trap the atoms, similar to how an egg carton holds eggs," said Georg Raithel, a U-M physics professor and co-author of a paper on the work published in the current edition of Physical Review Letters. Other co-authors are physics doctoral student Sarah Anderson and recent doctoral graduate Kelly Younge.


In previous Rydberg atom traps, atoms came to rest at the top of the peaks of the laser light lattice, and tended to escape. University of Michigan researchers solved this problem by quickly flipping the lattice, trapping the giant Rydberg atoms in the wells, like eggs in a carton. Image: Sarah Anderson

The researchers developed a unique way to solve a problem that had been limiting trapping efficiency to single digit percentages. For Rydberg atoms to be trapped, they first have to be cooled to slow them down. The laser cooling process that accomplishes that tended to leave the atoms at the peaks of what the researchers call the "lattice hills." The atoms didn't often stay there.

"To overcome this obstacle, we implemented a method to rapidly invert the lattice after the Rydberg atoms are created at the tops of the hills," Anderson said. "We apply the lattice inversion before the atoms have time to move away, and they therefore quickly find themselves in the bottoms of the lattice wells, where they are trapped."

Raithel says there is plenty of technological room left to reach 100 percent trapping efficiency, which is necessary for advanced applications. Rydberg atoms are candidates to implement gates in future quantum computers that have the potential to solve problems too complicated for conventional computers. They could also be used in terahertz imaging and detection devices that could be used in airport scanners or surveillance equipment.

This work is supported by the National Science Foundation and the Department of Energy. The paper is titled "Trapping Rydberg atoms in an optical lattice."

Source: University of Michigan - via ZeitNews.org

 

While some ‘bugs’ are like migratory birds, making tiny magnets that they use to guide their navigation, this is the first bacterium to be found that makes two different kinds of magnetic particles.

The report, “A Cultured Greigite-Producing Magnetotactic Bacterium in a Novel Group of Sulfate-Reducing Bacteria,” describes the first successful attempt to grow the bacterium in the laboratory, opening the door to understanding how it works, and potentially harnessing its tools for manufacturing or environmental cleanup.

Led by University of Nevada Las Vegas microbiologist Dennis Bazylinski, the team includes Ames Laboratory scientist Tanya Prozorov, who performed characterization studies of the cultured bacterium. Bazylinski, formerly an Iowa State University researcher, and his postdoctoral associate, Christopher Lefèvre found the new bacterium, named BW-1, in a basin named Badwater on the edge of Death Valley National Park.

Magnetotactic bacteria, which may be among the oldest organisms on the planet, produce intracellular magnetic nanocrystals, which allow the swimming bacteria to orient along the geomagnetic lines of Earth. Magnetotactic bacteria serve as inspiration and a source of mineralization proteins for room temperature synthesis of magnetite nanocrystals with controlled sizes and morphologies. The isolation of this newly identified organism and the growth, essentially from a single cell, of the culture, will allow for systematic studies on the largely unknown greigite (Fe3S4) biomineralization in magnetotactic bacteria.

“Typically, bacteria produce either magnetite or greigite, but not both,” Prozorov said, “so these ‘bugs’ are something new. Over several years, our research group has studied many different bacteria using (electron) microscopy with subsequent measurements of their magnetic properties.”

“Clearly, determining the morphology and chemistry of intracellular magnetic nanoparticles is the key to understand their physical properties,” she adds. “ Despite the best effort to produce such nanoparticles in vitro, bacterial nanocrystals are still superior, exhibiting different morphologies including rod and tooth shapes.”

A detailed examination of its DNA revealed that BW-1 has two sets of magnetosome genes unlike other that produce only one mineral and have only one set of magnetosome genes. This suggests that the production of magnetite and greigite in BW-1 is likely controlled by separate sets of genes. This could be important in the mass production of either mineral for specific applications.

Due to a slight difference in physical and magnetic properties, greigite might prove superior to iron oxide in some applications. Greigite is also an important magnetic mineral in the sedimentary record, and is thought to play a significant role in the cycling of iron sulfur in modern, and perhaps ancient environments.

These results might provide the insight on the chemical conditions under which this greigite is formed, and will be of great interest to a broad scientific community, ranging from microbiologists to materials scientists and astrobiologists.

Source: Ames Laboratory - via ZeitNews.org

 

Scientists are now trying to use plasmonic nanoparticles in cancer therapy whereby light energy is converted into heat in order to kill cancer cells. The advantage of such treatment is that it does not cause side effects that are common to chemotherapy. Mingyong Han at the A*STAR Institute of Materials Research and Engineering and co-workers have now developed gold plasmonic nanocrosses that are particularly suited to eliminating cancer cells in cancer therapy. The team demonstrated the usefulness of these nanocrosses by using them to kill human lung cancer cells.In general, metallic nanostructures have a particular frequency at which light excites electrons close to their surface. The collective movement of electrons, or resonance, in the metal is what converts the light energy into heat. The wavelength at which the resonance occurs is strongly dependent on the size and shape of the nanostructures.

For biomedical applications, the nanostructures should be effective no matter which direction they are illuminated from. Furthermore, the nanostructures should be efficient in absorbing near- to mid-infrared wavelengths because tissue is transparent to the light of these wavelengths.

Based on these requirements, the researchers decided to make gold nanocrosses (see image). In normal synthesis, however, gold would usually grow into the shape of the nanorods. To fabricate nanocrosses, the researchers added copper ions to the growth solution. The incorporation of small amounts of copper caused a twinning of the gold’s crystal structure, which in turn led to the growth of side arms from the crystal facets. “The unique cross-shaped gold structure enables multi-directional excitation to achieve a strong plasmonic resonance in the near- and mid-infrared region. This greatly lowers the laser power required for photothermal cancer therapy compared to nanorods,” says Han.

The researchers tested the performance of their gold nanocrosses by modifying their surfaces and binding them to human lung cancer cells. When irradiated with near-infrared laser light of relatively modest powers of 4.2 W/cm2 for 30 seconds, all cancer cells were killed. The researchers are now planning to test the effectiveness of the gold nanocrosses on animal models in future experiments.

Other applications of the gold nanocrosses are also possible, including photothermal imaging, in which small amounts of light are converted into local heat, or the sterilization of surfaces. “In our current research, we are studying gold nanocrosses for the photothermal destruction of superbugs on biofilms,” says Han.

Source: PhysOrg - via ZeitNews.org

 

The microneedles painlessly pierce the top layer of skin, then gradually deliver the medication within them by harmlessly dissolving into the patient's bloodstream. As an added bonus, once everything is complete, there are no bio-hazardous used needles to dispose of. Now, bioengineers from Massachusetts' Tufts University have developed what they claim is an even better type of microneedle, which is made from silk.

With some types of existing microneedles, the harsh conditions required for their production can destroy the sensitive biochemicals that they were supposed to deliver. It can also be difficult to fine-tune the rate at which they deliver their medication, plus infections can sometimes occur where they enter the skin. According to the Tufts scientists, their silk microneedles address all of these problems.

The team started with aluminum molding masters that contained arrays of microneedles, each needle measuring 500 micrometers in height, with tips less than 10 micrometers in diameter. An elastomer was cast over those masters to create a negative mold, then a drug-laden silk protein was cast over that mold. Once the silk was dry, it was removed from the mold, then further processed using water vapor and various other means.

The whole procedure was conducted under ambient pressure and temperature, and resulted in biocompatible, dissolving silk microneedles impregnated with the large-molecule drug, horseradish peroxidase.

Using methods such as varying the silk protein's drying time, the researchers were able to alter its structure, which in turn allowed them to precisely control its rate of drug release. It was also found that adding tetracycline to the protein inhibited the growth of Staphylococcus aureus bacteria at the application site on the skin.

As with other types of microneedles, the silk needles can be shipped and stored without refrigeration.

Source: GIZMAG - via ZeitNews.org

 
Ci sono 13301 persone collegate

< aprile 2024 >
L
M
M
G
V
S
D
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
         
             

Titolo
en - Global Observatory (605)
en - Science and Society (594)
en - Video Alert (346)
it - Osservatorio Globale (503)
it - Scienze e Societa (555)
it - Video Alerta (132)
ro - Observator Global (399)
ro - Stiinta si Societate (467)
ro - TV Network (143)
z - Games Giochi Jocuri (68)

Catalogati per mese - Filed by month - Arhivate pe luni:

Gli interventi più cliccati

Ultimi commenti - Last comments - Ultimele comentarii:
Now Colorado is one love, I'm already packing suitcases;)
14/01/2018 @ 16:07:36
By Napasechnik
Nice read, I just passed this onto a friend who was doing some research on that. And he just bought me lunch since I found it for him smile So let me rephrase that Thank you for lunch! Whenever you ha...
21/11/2016 @ 09:41:39
By Anonimo
I am not sure where you are getting your info, but great topic. I needs to spend some time learning much more or understanding more. Thanks for fantastic information I was looking for this info for my...
21/11/2016 @ 09:40:41
By Anonimo


Titolo





23/04/2024 @ 10:30:35
script eseguito in 1411 ms