US researchers have successfully expressed the precursor protein of insulin in lettuce and tobacco plants. Moreover, feeding these genetically modified plants to mice that have a tendency to become diabetic protected the animals against inflammation of the pancreas.
Generating the proinsulin protein in plants is a low-cost alternative to standard production methods, Dr. Henry Daniell, from the University of Central Florida in Orlando, and colleagues note in their report in the Plant Biotechnology Journal.
In the study, the scientists describe the creation of lettuce and tobacco chloroplast lines that produce a fusion protein consisting of a subunit of cholera toxin joined to human proinsulin, Reuters said.
Giving powered tobacco leaf to diabetic mice helped preserve insulin-producing beta-cells in the pancreas, Daniell’s team reports, and this was associated with lower levels of glucose in their blood and urine.
Due to the stigma associated with tobacco, the researchers have now moved on to using genetically engineered lettuce instead. They add that in light of the encouraging results in animals, testing in humans is now underway.

This artist's conception shows what the night sky might look like from a hypothetical planet around a star tossed out of an ongoing four-way collision between large galaxies.

F our galaxies are slamming into each other and kicking up billions of stars in one of the largest cosmic smash-ups ever observed. The clashing galaxies, spotted by NASA’s Spitzer Space Telescope, will eventually merge into a single, behemoth galaxy up to 10 times as massive as our own Milky Way. This rare sighting provides an unprecedented look at how the most massive galaxies in the universe form.
“Most of the galaxy mergers we already knew about are like compact cars crashing together,“ said Kenneth Rines of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. “What we have here is like four sand trucks smashing together, flinging sand everywhere.“
Collisions, or mergers, between galaxies are common in the universe. Gravity causes some galaxies that are close together to tangle and ultimately unite over millions of years. Though stars in merging galaxies are tossed around like sand, they have a lot of space between them and survive the ride. Our Milky Way galaxy will team up with the Andromeda galaxy in five billion years, Astronomy.com said. Mergers between one big galaxy and several small ones, called minor mergers, are well documented. For example, one of the most elaborate known minor mergers is taking place in the Spiderweb galaxy, a massive galaxy that is catching dozens of small ones in its “web“ of gravity. Astronomers have also witnessed “major“ mergers among pairs of galaxies that are similar in size. But no major mergers between multiple hefty galaxies have been seen until now.
The new quadruple merger was discovered serendipitously during a Spitzer survey of a distant cluster of galaxies, called CL0958+4702, located nearly five billion light-years away. The infrared telescope first spotted an unusually large fan-shaped plume of light coming out of a gathering of four blob-shaped, or elliptical, galaxies. Three of the galaxies are about the size of the Milky Way, while the fourth is three times as big.
Further analysis of the plume revealed it is made up of billions of older stars flung out and abandoned in an ongoing clash. About half of the stars in the plume will later fall back into the galaxies. “When this merger is complete, this will be one of the biggest galaxies in the universe,“ said Rines.

Digital photographers could soon be able to erase unwanted elements in photos by using tools that scan for similar images in online libraries.
Research teams have developed an algorithm that uses sites like Flickr to help discover light sources, camera position and composition in a photo.
Using this data the tools then search for objects, such as landscapes or cars that match the original.
The teams aim to create image libraries that anyone can use to edit snaps.
James Hays and Alexei Efros from Carnegie Mellon University have developed an algorithm to help people who want to remove bits of photographs.
The parts being removed could be unsightly lorries in the snaps of the rural idyll where they took a holiday or even an old boyfriend or girlfriend they want to rub out from a photograph, BBC reported.
To find suitable matching elements, the research duo’s algorithm looks through a database of 2.3 million images culled from Flickr.
“We search for other scenes that share as closely as possible the same semantic scene data,“ said Hays, who has been showing off the project at the computer graphics conference Siggraph, in San Diego.
In this sense “semantic“ means composition. So a snap of a lake in the foreground, hills in a band in the middle and sunset above has, as far as the algorithm is concerned, very different “semantics“ to one of a city with a river running through it.
The broad-based analysis cuts out more than 99.9 percent of the images in the database, said Hays. The algorithm then picks the closest 200 for further analysis.
Next the algorithm searches the 200 to see if they have elements, such as hillsides or even buildings, the right size and colors for the hole to be filled.
The useful parts of the 20 best scenes are then cropped, added to the image being edited so the best fit can be chosen.
Early tests of the algorithm show that only 30 percent of the images altered with it could be spotted, said Hays.
The other approach aims to use net-based image libraries to create a clip-art of objects that, once inserted into a photograph, look convincing.
“We want to generate objects of high realism while keeping the ease of use of a clip art library,“ said Jean-Francois Lalonde of Carnegie Mellon University who led the research.
To generate its clip art for photographs the team has drawn on the net’s Label Me library of images which has many objects, such as people, trees and cars, cut out and tagged by its users.
The challenge, said Lalonde, was working out which images in the Label Me database will be useful and convincing when inserted into photographs.
The algorithm developed by Lalonde and his colleagues at Carnegie Mellon and Microsoft Research analyses scenes to find out the orientation of objects and the sources of light in a scene.

New research suggests that a nutrient in red meat, poultry and dairy products may contribute to the development of intestinal polyps, which can lead to colon cancer.
The study, which involved women only, was preliminary, and no one is yet suggesting a change in diet as a result.
However, the research into the nutrient, called choline, could ultimately lead to new dietary recommendations, said Eunyoung Cho, an epidemiologist at Brigham and Women’s Hospital in Boston.
“There may be some impact,“ Cho said. “But this is one study, and it’s hard to make any conclusion based on this study.“
The role played by choline, a nutrient required by the body, has been unclear. Some researchers had thought it might provide protection against colon cancer, which kills an estimated 52,000 people in the United States each year, according to the American Cancer Society. The disease is the second biggest cancer killer in the United States after lung cancer, HealthDay reported.
In the new study, Cho and colleagues looked at nurses enrolled in a large study. They found more than 39,000 women who were free of colon cancer and then underwent at least one endoscopic examination between 1984 and 2002. Polyps--benign growths that can lead to colon cancer--were found in more than 2,400 of the women.
Women who ate the most choline in their food were 1.45 times more likely to have polyps, the team reported in the Aug. 7 online issue of the Journal of the National Cancer Institute.
Having more polyps doesn’t necessarily mean more cancer, and future research will explore whether those who ate the most choline actually developed tumors, Cho said. Studies also need to look into the impact of choline on men.
Why might choline contribute to polyps, and possibly colon cancer, in the first place? The nutrient is a major component of the membranes of cells, Cho said, “and the tumor cell may need choline.“
Currently, health officials recommend that people prevent colon cancer by eating a lot of fiber along with fruits and vegetables. Red meat, meanwhile, is thought to increase risk.
That dietary advice isn’t likely to change even if choline turns out to be a possible villain, said Regina Ziegler, a senior investigator with the National Cancer Institute, who co-wrote a commentary accompanying the new study. “What they’re finding is consistent“ with the recommendations, she said.

An extensive survey failed to find any sign of the Yangtze River dolphin, also known as baiji.

A freshwater dolphin found only in China is now “likely to be extinct“, a team of scientists has concluded.
The researchers failed to spot any Yangtze River dolphins, also known as baijis, during an extensive six-week survey of the mammals’ habitat, BBC said.
The team blamed unregulated fishing as the main reason behind their demise.
If confirmed, it would be the first extinction of a large vertebrate for over 50 years.
Sam Turvey of the Zoological Society of London (ZSL), one of the paper’s co-authors, described the findings as a “shocking tragedy“.
“The Yangtze river dolphin was a remarkable mammal that separated from all other species over 20 million years ago,“ Dr Turvey explained.
“This extinction represents the disappearance of a complete branch of the evolutionary tree of life and emphasises that we have yet to take full responsibility in our role as guardians of the planet.“
If confirmed, it would be the first extinction of a large vertebrate for over 50 years.
The species (Lipotes vexillifer) was the only remaining member of the Lipotidae, an ancient mammal family that is understood to have separated from other marine mammals, including whales, dolphins and porpoises, about 40-20 million years ago.
The white, freshwater dolphin had a long, narrow beak and low dorsal fin; lived in groups of three or four and fed on fish.
The team carried out six-week visual and acoustic survey, using two research vessels, in November and December 2006.
“While it is conceivable that a couple of surviving individuals were missed by the survey teams,“ the team wrote, “our inability to detect any baiji despite this intensive search effort indicates that the prospect of finding and translocating them to a [reserve] has all but vanished.“
The scientists added that there were a number of human activities that caused baiji numbers to decline, including construction of dams and boat collisions.
“Unlike most historical-era extinctions of large bodied animals, the baiji was the victim not of active persecution but incidental mortality resulting from massive-scale human environmental impacts - primarily uncontrolled and unselective fishing,“ the researchers concluded.

Green tea, already shown to suppress inflammation, helps by regulating the expression of Caspase-14, a protein in genes that regulates the life cycle of a skin cell.

Green tea could hold promise as a new treatment for skin disorders such as psoriasis and dandruff, Medical College of Georgia researchers say.
Researchers studied an animal model for inflammatory skin diseases, which are often characterized by patches of dry, red, flaky skin caused by the inflammation and overproduction of skin cells. Those treated with green tea showed slower growth of skin cells and the presence of a gene that regulates the cells’ life cycles, Science Daily
reported.
“Psoriasis, an autoimmune disease, causes the skin to become thicker because the growth of skin cells is out of control,“ says Dr. Stephen Hsu, an oral biologist in the MCG School of Dentistry and lead investigator on the study published in the Aug. 18 edition of Experimental Dermatology. “In psoriasis, immune cells, which usually protect against infection, instead trigger the release of cytokines, which causes inflammation and the overproduction of skin cells.“
Other autoimmune diseases with similar side effects include lupus, which can lead to skin lesions, and dandruff.
Green tea, already shown to suppress inflammation, helps by regulating the expression of Caspase-14, a protein in genes that regulates the life cycle of a skin cell.
“That marker guides cells by telling them when to differentiate, die off and form a skin barrier,“ Dr. Hsu says. “In people with psoriasis, that process is interrupted and the skin cells don’t die before more are created and the resulting lesions form.“
Animal models treated with green tea also showed reduced levels of proliferating cell nuclear antigen, a gene expressed when skin cells multiply.
“Before treatment, the antigen, PCNA, was present in all layers of the skin,“ Dr. Hsu says. “Typically, PCNA is only found in the basal layer, the innermost layer where skin cells continually divide and new cells push the older ones to the skin surface, where they eventually slough off. After being treated with green tea, the animal models showed near-normal levels of PCNA in only the basal layers.“

Six new species, including a bat and two frogs, have been discovered in Democratic Republic of the Congo in an eastern area off limits to scientists for decades because of violence, a wildlife group said.
The New York-based Wildlife Conservation Society said researchers conducted a survey of a remote forested region just west of Lake Tanganyika between January and March.
“If we can find six new species in such a short period it makes you wonder what else is out there,“ said researcher Andrew Plumptre.
The new species discovered were a bat, a rodent, two shrews and two frogs.
Aid agencies estimate around 4 million Congolese have been killed in fighting or by related hunger and disease since the outbreak of the country’s 1998-2003 war, in which six foreign armies joined in fighting over its huge mineral riches, Reuters said.
Despite a 2003 peace deal and the country’s first free elections in more than 40 years being held last year, militia fighting continues in parts of the east.
“In spite of the conflict and related degradation in the area, the survey team found that some 1,000 square kilometers have remained intact, from the shores of Lake Tanganyika up to elevations of 2,725 meters above sea level,“ a statement said.
It said the area had been off limits to scientists since 1960 because of instability. The team also included researchers from the Field Museum in Chicago, the National Centre of Research and Science in Lwiro and the World Wildlife Fund.
The statement said the forest was extremely rich in biodiversity, containing a large number of chimpanzees, buffalo, elephants, leopards and monkeys.
Around 10 percent of the plant samples collected have yet to be identified.
“Given the findings with the vertebrates, it is likely that some of the plants will represent new species as well,“ said Ben Kirunda of the group’s botanical team.
The researchers said they met village leaders who were mostly supportive of making the region a protected area.
“Since few people live there, it would be relatively easy to create a park while supporting the livelihoods of people who live in the landscape,“ said James Deutsch, director of the Wildlife Conservation Society’s Africa Program.
Democratic Republic of the Congo’s wildlife, particularly mountain gorillas in the Virunga National Park, was a significant tourist attraction before the 1998-2003 war.