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Pathogens Vs Weed
"The use of plant pathogens to suppress weeds is considered as one of the alternative weed control options for areas or production systems where the use of chemical herbicides is not permitted or feasible," said Erin Rosskopf, USDA, Agricultural Research Service, Fort Pierce, FL. "Plant pathogens may also be used when the herbicide selection or usage must be rotated with other control methods in order to prevent the development of resistant weeds or lessen the impact of herbicides on the environment," she said.
Weed management is important due to the amount of damage weeds can cause to agricultural productivity. Weeds can reduce crop yields by as much as 12 percent (causing up to $32 billion in losses), based on the potential value of all U.S. crops of approximately $267 billion/year. Weeds also pose serious ecological problems. Invasive weeds are capable of altering ecosystem processes and displacing native plant and animal species. In addition, weeds serve as reservoirs for plant pathogens that impact crops.
As per Rosskopf, there are two approaches used for managing weeds with plant pathogens-the classical biological control approach and the bioherbicides approach. The classical biocontrol approach uses a pathogen imported from a foreign location to control a native or naturalized weed with minimal technological manipulations.........
Posted by: Beverly Permalink Source
A New Better Water Test
A new method for detection and measurement of small amounts of water, developed in the lab of Dr. Milko van der Boom in the Weizmann Institute's Organic Chemistry Department, might allow such tests to be performed accurately and quickly. Van der Boom and postdoctoral fellow Dr. Tarkeshwar Gupta created a versatile film on glass that is only 1.7 nanometers thick. The film can measure the number of water molecules in a substance even when it contains only a few parts per million.
"The problem," says van der Boom, "is that water is hard to detect and to quantify." His method is a departure from previous sensing techniques. In general, such sensor systems are based on relatively weak but selective "host-guest" interactions. In the Weizmann Institute team's sensor, metal complexes embedded in the film steal electrons from the water molecules. When the number of electrons in the metal complexes changes, so does their color, and this change can be read optically. Devices based on optical readout do not need to be wired directly to larger-scale electronics an issue that's still a tremendous challenge for much of molecular-based electronics.........
Posted by: Beverly Permalink Source
How Cancer Drug Aids An Anti-cancer Virus
The virus, a modified herpes simplex virus, is injected directly into the tumor, where it enters only the cancer cells and kills them. The study found, however, that within hours of the injection, infection-fighting immune cells are drawn into the tumor to attack the virus, reducing the treatment's effectiveness.
They also found that a chemotherapeutic drug called cyclophosphamide briefly weakens those immune cells, giving the anti-cancer virus an opportunity to spread more completely through the tumor and kill more cancer cells.
Specifically, the drug slows the activity of immune cells called natural killer (NK) cells and macrophages, which are the body's first line of defense against infections.
The virus and drug cannot be used yet in humans because they require further study, as well as testing for safety and effectiveness through the clinical trials process.
The research, led by scientists with the Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, is published in the Aug. 22 issue of the Proceedings of the National Academy of Sciences.........
Posted by: Beverly Permalink Source
Cylindropuntia Bigelovii
Despite the common name of teddybear cholla, you do not want to hug this plant. Its needles have barbed ends that pierce and lodge. Tweezers or a comb are recommended to pick the needles out if they become embedded in your skin; attempting to pluck them out with your fingers will merely sink them into your fingertips (as I experienced).
The Living Desert has a good resource page on teddybear cholla, while Brad Biringer has photographs of the Cholla Cactus Garden taken in superior light conditions in this photo essay.
Photography resource link: Photoshop Tips and Tricks from the tips section of the Pacific Northwest Nature Photographers group.........
Posted by: Beverly Permalink Source
Greener Path To Iron Production
droplet of molten iron held by a magnet
The American Iron and Steel Institute (AISI) announced recently that the team, led by Donald R. Sadoway of the Department of Materials Science and Engineering, has shown the technical viability of producing iron by molten oxide electrolysis (MOE).
"What sets molten oxide electrolysis apart from other metal-producing technologies is that it is totally carbon-free and hence generates no carbon dioxide gases -- only oxygen," said Lawrence W. Kavanagh, AISI vice president of manufacturing and technology.
The work was funded by the AISI/Department of Energy Technology Roadmap Program (TRP). The TRP goal is to increase the competitiveness of the U.S. steel industry while saving energy and enhancing the environment. According to the AISI, the MIT work "marks one of TRP's breakthrough projects toward meeting that goal".
Unlike other iron-making processes, MOE works by passing an electric current through a liquid solution of iron oxide. The iron oxide then breaks down into liquid iron and oxygen gas, allowing oxygen to be the main byproduct of the process.
Electrolysis itself is nothing new -- all of the world's aluminum is produced this way. And that is one advantage of the new process: It is based on a technology that metallurgists are already familiar with. Unlike aluminum smelting, however, MOE is carbon-free.........
Posted by: Beverly Permalink Source
Fuel Cells To Power Unmanned Aerial Vehicle
Thomas Bradley and Reid Thomas go through the procedure of starting up the fuel cell aircraft
The fuel-cell system that powers the 22-foot wingspan aircraft generates only 500 watts. "That raises a lot of eyebrows," said Adam Broughton, a research engineer who is working on the project in Georgia Tech's Aerospace Systems Design Laboratory (ASDL). "Five hundred watts is plenty of power for a light bulb, but not for the propulsion system of an aircraft this size." In fact, 500 watts represents about 1/100th the power of a hybrid car like a Toyota Prius.
A collaboration between ASDL and the Georgia Tech Research Institute (GTRI), the project was spearheaded by David Parekh, GTRI's deputy director and founder of Georgia Tech's Center for Innovative Fuel Cell and Battery Technologies.
Parekh wanted to develop a vehicle that would both advance fuel cell technology and galvanize industry interest. While the automotive industry has made strides with fuel cells, apart from spacecraft, little has been done to leverage fuel cell technology for aerospace applications, he noted.
"A fuel cell aircraft is more compelling than just a lab demonstration or even a fuel cell system powering a house," Parekh explained. "It's also more demanding. With an airplane, you really push the limits for durability, robustness, power density and efficiency".........
Posted by: Beverly Permalink Source
First Quantum Cryptographic Data Network
"The volume and type of sensitive information being transmitted over data networks continues to grow at a remarkable pace," said Prem Kumar, professor of electrical engineering and computer science at Northwestern's Robert R. McCormick School of Engineering and Applied Science and co-principal investigator on the project. "New cryptographic methods are needed to continue ensuring that the privacy and safety of each user's information is secure".
Kumar's research team recently demonstrated a new way of encrypting data that relies on both traditional algorithms and on physical principles. This QDE method, called AlphaEta, makes use of the inherent and irreducible quantum noise in laser light to enhance the security of the system and makes eavesdropping much more difficult. Unlike most other physical encryption methods, AlphaEta maintains performance on par with traditional optical communications links and is compatible with standard fiber optical networks.........
Posted by: Beverly Permalink Source
Nanocantilevers Yield Surprises
The nanocantilevers, which resemble tiny diving boards made of silicon, could be used in future detectors because they vibrate at different frequencies when contaminants stick to them, revealing the presence of dangerous substances. Because of the nanocantilever's minute size, it is more sensitive than larger devices, promising the development of advanced sensors that detect minute quantities of a contaminant to provide an early warning that a dangerous pathogen is present.
The researchers were surprised to learn that the cantilevers, coated with antibodies to detect certain viruses, attract different densities - or quantity of antibodies per area - depending on the size of the cantilever. The devices are immersed into a liquid containing the antibodies to allow the proteins to stick to the cantilever surface.
"But instead of simply attracting more antibodies because they are longer, the longer cantilevers also contained a greater density of antibodies, which was very unexpected," said Rashid Bashir, a researcher at the Birck Nanotechnology Center and a professor of electrical and computer engineering and biomedical engineering at Purdue University. The research also shows that the density is greater toward the free end of the cantilevers.........
Posted by: Beverly Permalink Source
surviving months without oxygen
Image courtesy of University of Oslo
This study, which comes from Finland, showed that the amount of glycogen in the brain was at its peak in February, when the pond becomes nearly depleted of oxygen. Glycogen, which is an energy supply that the carp brain uses to survive lack of oxygen, was 15 times higher in February, in comparison to brain glycogen content in July, when oxygen in the pond is at its peak.
At the same time, the carp brain's sodium-potassium pump activity, a measure of energy demand, decreased 10-fold to its low point between February and April, said the study's lead author, Vesa Paajanen. Taken together, these findings indicate the carp extends the amount of time it can survive without oxygen in frigid water by 150-fold. Further, the study observed that it was the dropping water temperature that sets these physiological changes into motion.
"This is the first study to show that sodium pump activity is controlled by water temperature, not by the amount of oxygen available in the water" Paajanen said. The findings help explain how the carp pulls off the remarkable physiological feat that allows its brain to survive for months in a nearly anoxic state.........
Posted by: Beverly Permalink Source
Bees Calculation Sets Industry Buzzing
Researchers at Cardiff University's Manufacturing Engineering Centre (MEC) developed the procedure, or algorithm, after observing the "waggle dance" of bees foraging for nectar. The algorithm enables companies to maximise results by changing basic elements of their processes.
When a bee finds a source of nectar, it returns to the hive and performs a dance to show other bees the direction and distance of the flower patch and how plentiful it is. The other workers then decide how many of them will fly off to find the new source, depending on its distance and quality.
The MEC team's Bees Algorithm mimics this behaviour. A computer can be set up to calculate the results of different settings on a manufacturing process. More computing power is then devoted to searching around the most successful settings, in the same way as more bees are sent to the most promising flower patches.
The Algorithm has been shown to cope with up to 3,000 variables and is faster than existing calculations. By entering basic data about all or part of a company, or even just one machine, the MEC team can calculate the best outcome for a wide range of business processes. They have already used the Bees Algorithm to work out the most efficient settings on welding systems and for the design of springs.........
Posted by: Beverly Permalink Source
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