Science and Technology

Citrus Greening a Deadly Fruit Disease

Citrus greening disease is an important disease of citrus which greatly affects the production of the fruits in several parts of India. Characteristic symptoms include yellowing of leaf veins and adjacent tissues, followed by premature defoliation, dieback of twigs, decay of feeder rootlets and lateral roots. Infected fruits are small, lopsided with bitter taste. Such fruits may fall prematurely; while those that remain on the tree do not colour properly, remaining green on the shaded side.

Management

Routinely scout citrus for signs of greening so that infected trees can be removed. Scouting should be done at least four times a year, or more in areas known to have infected trees. October through March is the best time for scouting, but symptoms can be present at other times of the year. For effective management remove infected trees.
This is the only way to ensure that they won’t remain a source of infection for other trees. Pruning symptomatic limbs is often ineffective since other parts of the tree may be infected, but do not show symptoms. Before removing, the tree should be sprayed with a foliar insecticide to kill any psyllids in order to keep them from moving on once the tree is removed. Focus Integrated Pest Management (IPM) efforts on using disease-free nursery trees, reducing infection sources (inoculum) by frequent surveys and diseased tree removal, and suppressing Asian citrus psyllid through area-wide management

Foliar spray

Spray foliar insecticide prior to tree removal. Increase frequency of scouting in areas where infected trees have been removed. The complex of natural enemies attacking ACP around the world usually includes various species of ladybeetles, syrphid flies, lacewings, spiders.
Use soil-applied systemic insecticides on young trees. Foliar sprays of fenpropathrin (Danitol 2.4 EC), chlorpyrifos (Lorsban 4EC), petroleum oil (2 per cent rate).

World’s First Gun Made From 3D Printer Technology

The first gun of the world made out of 3D printer technology was fired successfully in US. Defense Distributed created this firearm and the form also planned to make these blueprints available online. Defense Distributed spent a year for creation of this firearm, which was fired successfully on 4 May 2013 at firing range south of Austin, Texas.
The anti-gun campaigners criticised this project, while the law enforcement of Europe is monitoring the developments of this project.
Victoria Baines of cybercrime centre of Europol explained that the criminals at present were likely to pursue the established routes for obtaining these firemans, but with the passage of time, the 3D printer technology would become more user-friendly as well as cost-effective, thereby posing risks. Cody Wilson, 25, a student of the University of Texas is the head of Defense Distributed. 3D printing has successfully been called the future of manufacturing.

Working of the 3D Printer Technology

The 3D printer technology works by building layer upon layer of the material, which is basically plastic. This is done in order to build the complex and solid objects. This technology is cheaper and instead of buying the goods from markets, the consumers will be able to download its designs. Then these can be printed out at the home itself.
However, like all technologies, there are advantages as well as disadvantages. The first gun of the world made out of 3D printer technology cost 8000 US dollar from eBay. The gun was assembled from different printed components which were made out of ABS plastic. The firing pin was made out of metal.
Cody Wilson was fiven the manufacturing as well as seller’s license from US Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) in order to make this gun. US Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) official Donna Sellers explained that the gun was legal in US as long as it wasn’t a National Firearms Act weapon. 3D printing technology was used in the past by certain criminal organisations for creation of card readers – skimmers, which are inserted in the bank machines. Law enforcement agencies across the world have professionals for monitoring cybercrimes.

New Less Expensive Technique of Creating 3D Images

Scientists at University of Glasgow’s School of Physics and Astronomy discovered a new less expensive technique of creating 3D images. They created a system which makes use of the detectors that have single pixel for sensing the light instead of various pixels used in imaging sensors found in digital cameras.
The detectors have the capability of judging the frequencies beyond visible light, which in turn would help in various new applications for 3D imaging in geography and medicine. The scientists explained that the single pixel detectors will cost just a few pounds in comparison to present systems which amount to thousands of pounds. The scientists believe that the ability of this system to sense the wavelengths beyond digital cameras’ capabilities, as well as its low cost would result in making it a valuable tool for various industries.
Possible applications include use in medical industry for finding tumours. Prof Miles Padgett, the lead researcher of the team at University of Glasgow’s School of Physics and Astronomy explained that single pixel detectors in four locations can be used for detecting the light from data projector, which elucidates objects with the sequence of black-and-white patterns. 3D images were created with the combination of images from four detectors while making use of a technique known as shape from shade. The 3D computational imaging, also known as ghost imaging produces the detailed images of the objects in merely a few seconds. Conventional 3D imaging systems make use of multiple digital camera sensors for producing 3D image from 2D information. However, there is a need of careful calibration for making sure that multi-megapixel images align properly. The digital camera sensors have restricted sensitivity beyond spectrum of light, where single pixel detector can be used for capturing information beyond visible reaching wavelengths from the X-ray to TeraHertz.

First Global Model developed to analyse the Routes of Marine Species

Scientists developed the first global model that analyses the routes taken by marine invasive species. They examined the movements of cargo ships across the world to detect the hot spots where these aquatic aliens could thrive. Marine species wreak havoc in new locations causing the extinction of natives.
A well-documented boom has been observed in global shipping over the last 20 years and this has resulted into growing numbers of species moving via ballast tanks. The ports such as San Francisco and Chesapeake Bay have informed about several exotic new species arriving every year. Economic data indicates that marine invaders can have effects that last for decades. Therefore, scientists came out with a model that can curb these marine species. They procured detailed logs from nearly three million voyages that happened in 2007 and 2008.

Hytholamus the Mechanism Responsible for Ageing

The US team of scientists found the mechanism in the hypothalamus- which is located deep inside the brain- and showed that it is responsible for the ageing process. Scientists carried out a series of experiments to find that they could extend the lives of mice by a fifth, without the problems such as animals suffering from muscle weakness, bone loss or memory problems associated with old age. Scientists discovered that a chemical called NF-kB became more active in the hypothalamus of mice as they reached old age. When they blocked NF-kB, mice lived up to 1100 days, compared with 600 to 1000 days in normal condition. But all the mice died within 900 days, when NF-kB was given to them in abundance. Further experiment showed that NF-kB reduced levels of a hormone called GnRH, which plays a key role in fertility and the development of sperm and eggs. When the mice were given daily dose of GnRH, it resulted into fresh neurons growing in their brains.

Tiny Movie at Molecular Level

Scientists have taken the idea of a film short down to new levels. Molecular levels. IBM says it has made the tiniest stop-motion movie ever, a one-minute video of individual carbon monoxide molecules repeatedly rearranged to show a boy dancing, throwing a ball and bouncing on a trampoline. Each frame measures 45 by 25 nanometres. There are 25 million nanometres in an inch but hugely magnified, the movie (http-//bit.ly/17ZmHIt ) is reminiscent of early video games, particularly when the boy bounces the ball off the side of the frame accompanied by simple music and sound effects. The movie is titled “A Boy and His Atom.” Videos showing atoms in motion have been seen before but Andreas Heinrich, IBM’s principal scientist for the project, said Tuesday this is the first time anything so small has been manoeuvred to tell a story. “This movie is a fun way to share the atomic-scale world,” Heinrich said. “The reason we made this was not to convey a scientific message directly, but to engage with students, to prompt them to ask questions.”