jueves, 18 de septiembre de 2014
Scientists have "hacked" photosynthesis, and it could help them speed up food production
An enzyme found in algae can make plants convert carbon dioxide into sugar more efficiently.
Photosynthesis is the crucial process by which plants convert sunlight, water and air into energy and food - and scientists from the US and UK have now taken the first step towards speeding the process up using enzymes from blue-green algae.
For decades scientists have seen room for improvement in the photosynthesis process - mainly in the activity of an enzyme called Rubisco. Rubisco is the protein that converts CO2 into sugar, and is possibly the most abundant protein on Earth, accounting for up to half of all the soluble protein found in leaves.
But the reason it’s so common is because it’s not very efficient - and researchers have long been searching for a way to boost its output.
They then engineered the Rubisco gene into the genome of a tobacco plant's chloroplast - the organelle in plants where photosynthesis occurs. They discovered that these plants were able to confer CO2 into sugar faster than normal tobacco, a sign that photosynthesis had been sped up.
"This is the first time that a plant has been created through genetic engineering to fix all of its carbon by a cyanobacterial enzyme," said Hanson in a press release. "It is an important first step in creating plants with more efficient photosynthesis." published in Nature.
Importantly, they add two extra bacterial proteins to the crops. Hanson told journalist Herkewitz from Popular Mechanics that this is likely to have helped the tobacco plant utilise the more efficient Rubisco.
At the moment the algal Rubisco, while more efficient, can waste energy by reacting with oxygen rather than CO2. Currently the scientists are overcoming this by growing the plants in chambers that maintain artificially high CO2 levels, but that’s obviously not a long-term solution.
Usually the blue-green algae overcome this problem by creating structures called carboxysomes around their Rubisco enzymes, creating a CO2-rich environment, but obviously this isn't something that occurs naturally in tobacco plants.
But there is hope - in June, the team reported that they’d engineered tobacco plants that could generate carboxysome-like structures. So the next step is to try to engineer the algal Rubisco enzyme into these plants to see if this helps to make them more efficient.
The scientists used tobacco plants for this experiment as their genome is so well studied, but this technique will also need to be tested in food crops if we have any hope of using it to help us increase our food production.
viernes, 12 de septiembre de 2014
Like many of the screens that we view today, the new Cambridge invention uses an electrophoretic display that rearranges particles suspended in a solution by means of an electric field. However, in contrast to most displays the screen is made of flexible plastic and its pixel electronics, also known as backplane, replace the traditional metal electrode with one built from graphene.
What’s more the 2-dimensional carbon material is also processed and printed very easily making the display simple to produce.
Currently, the Cambridge consortium’s display is only capable of a 150 pixel per inch resolution, however, that may change in short order. Looking further into the future the UK team also believes that using graphene-based backplanes might allow them to embed sensors in the displays, making them more capable of interacting with their viewers.
“We are happy to see our collaboration with Plastic Logic resulting in the first graphene-based electrophoretic display exploiting graphene in its pixels’ electronics,” said Professor Andrea Ferrari, Director of the Cambridge Graphene Centre.
While graphene’s potential has been known since it was first discovered, industries have been slow to leverage its unique abilities. This Cambridge display should do wonders for the development of process engineering for graphene and in the end it might just dazzle us with beautiful, flexible moving images.
martes, 4 de marzo de 2014
To get water and minerals up a tree, wood is comprised of xylem, porous tissue arranged in tubes for conducing sap from the roots upwards through a system of vessels and pores.
Tiny pores called pit membranes are scattered throughout the walls of the vessels, allowing sap to flow from one vessel to another, feeding various structures along a tree’s length.
Additionally, the pores also trap air bubbles, which could kill a tree if spread in the xylem.
“Plants have had to figure out how to filter out bubbles but allow easy flow of sap,” study author Rohit Karnik from MIT says in a news release .
So it’s a nice coincidence that the problems are similar.”
As Karnik’s team finds, a small piece of sapwood can filter out more than 99 percent of the E.
They tested their improvised filter using water mixed with particles ranging in size. coli through the sapwood filter, they saw how bacteria had accumulated around the pores in the first few millimeters of the wood.
Existing water-purification technologies that use chlorine treatments and membranes with nano-scale pores are expensive.
jueves, 27 de febrero de 2014
Often, those materials are transferred to offsite locations, which wastes time and resources.
The process also wastes a lot of water in order to prevent harmful dust clouds from blooming.
However, a Swedish student’s concrete-eating robot aims to change all that.
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“The ERO Concrete Recycling Robot was designed to efficiently disassemble concrete structures without any waste, dust or separation and enable reclaimed building materials to be reused for new prefabricated concrete buildings,” explained Omer Haciomeroglu of the Umea Institute of Design of Design.
”It does so by using a water jet to crack the concrete surface, separate the waste and package the cleaned, dust-free material.”
The idea is to send in a fleet of the ERO robots that will scan buildings to determine the best route to execute demolition.
Once the robot goes to work, using vacuum suction and electrical power, it erases the building.
“ERO deconstructs with high-pressure water and sucks and separates the mixture of aggregate, cement and water.
It then sends aggregate and filtered cement slurry separately down to the packaging unit to be contained,” Haciomeroglu wrote.
”Clean aggregate is packed into big bags, which are labeled and sent to nearby concrete precast stations for reuse.
Water is recycled back into the system.”
Turbulence dynamos strategically placed inside air suction chambers even provide a percentage of ERO’s energy needs.
Once the last wall has been demolished, essentially nothing has gone to landfills or been sent away for additional processing.
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“Even the rebar is cleaned of concrete, dust and rust and is ready to be cut and reused immediately,” Haciomeroglu stated.
“Every bit of the load-bearing structure is reusable for new building blocks.”
So far the design remains a concept, but influential organizations are starting to take note.
Last year, Haciomeroglu’s concept won in the Student Designs category of the International Design Excellence Awards.
martes, 11 de febrero de 2014
New Desalination Technique Also Cleans and Disinfects Water
Electrodialysis has the potential to desalinate seawater quickly and cheaply but does not remove other contaminants such as dirt and bacteria.
One of the world’s most pressing needs is to supply clean drinking water to the its population.
The most common method is to distil seawater in a vacuum so that its boiling point is lower than usual.
This works by pumping water through a membrane that does not allow sodium or chlorine ions to pass.
That’s significantly less energy intensive than traditional desalination methods but is limited by the rate at which water can pass through the membrane.
miércoles, 5 de febrero de 2014
LONDON (Reuters) - Dennis Aabo Sorensen lost his left hand when a firework rocket he was holding exploded during New Year's Eve celebrations 10 years ago, and he never expected to feel anything with the stump again.
But for a while last year he regained his sense of touch after being attached to a "feeling" bionic hand that allowed him to grasp and identify objects even when blindfolded.
The prototype device, which was wired to nerves in the 36-year-old Dane's left arm, blurs the boundary between body and machine and scientists hope it could one day revolutionize the lives of many amputees.
There is still work to be done in miniaturizing components and tidying away trailing cables that mean the robotic hand has so far only been used in the lab, but Sorensen said the European research team behind the project had got the basics right.
Ultra-thin electrodes the width of a human hair were surgically implanted into the ulnar and median nerves of Sorensen's arm before he was attached to the robotic hand, which is equipped with various artificial sensors.
jueves, 19 de septiembre de 2013
San Diego, CA, September 17, 2013 -- University of California, San Diego bioengineering professor Gert Cauwenberghs has been selected by the National Science Foundation to take part in a five-year, multi-institutional, $10 million research project to develop a computer vision system that will approach or exceed the capabilities and efficiencies of human vision. The Visual Cortex on Silicon project, funded through NSF's Expeditions in Computing program, aims to create computers that not only record images but also understand visual content and situational context in the way humans do, at up to a thousand times the efficiency of current technologies, according to an NSF announcement.
Smart machine vision systems that understand and interact with their environments could have a profound impact on society, including aids for visually impaired persons, driver assistance capabilities for reducing automotive accidents, and augmented reality systems for enhanced shopping, travel, and safety.
For their part in the effort, Cauwenberghs, a professor in the Department of Bioengineering at the UC San Diego Jacobs School of Engineering, and his team are developing computer chips that emulate how the brain processes visual information. "The brain is the gold standard for computing," said Cauwenberghs, adding that computers work completely differently than the brain, acting as passive processors of information and problems using sequential logic. The human brain, by comparison, processes information by sorting through complex input from the world and extracting knowledge without direction.
While several computer vision systems today can each successfully perform one or a few human tasks-such as detecting human faces in point-and-shoot cameras-they are still limited in their ability to perform a wide range of visual tasks, to operate in complex, cluttered environments, and to provide reasoning for their decisions. In contrast, the visual cortex in mammals excels in a broad variety of goal-oriented cognitive tasks, and is at least three orders of magnitude more energy efficient than customized state-of-the-art machine vision systems.
Cauwenberghs and his collaborators around the country aim to understand the fundamental mechanisms used in the visual cortex, with the hope of enabling the design of new vision algorithms and hardware fabrics that can improve power, speed, flexibility and recognition accuracies relative to existing computer vision systems.
Cauwenberghs said the Visual Cortex on Silicon project offers a unique collaborative opportunity with experts across the globe in neuroscience, computer science, nanoengineering and physics.
The project has other far-reaching implications for neuroscience research. By developing chips that can function more like the human brain, Cauwenberghs believes researchers can achieve a number of significant breakthroughs in our understanding of brain function from the work of single neurons all the way up to a more holistic view of the brain as a system. For example, building chips that model different aspects of brain function, such as how the brain processes visual information, gives researchers a more robust tool to understand where problems arise that contribute to disease or neurological disorders.
The Expeditions in Computing program, which started in 2008, represents NSF's largest single investments in computer science research. As of today, 16 awards have been made through this program, addressing subjects ranging from foundational research in computing hardware, software and verification to research in sustainable energy, health information technology, robotics, mobile computing, and Big Data.