Archive for the ‘University of Florida’ Category

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by Sydney Lupkin

Every morning at 3 a.m. Lora Pournazarian is awake to feed her 8-year-old son Jonah a mixture of corn starch and water through a tube in his stomach.

If she doesn’t, Jonah could die because he has a rare form of glycogen storage disease, a hereditary disorder that means his liver can store sugar but can’t release it, causing him to have dangerously low blood sugar levels that can result in seizures or even death.

“That’s huge anxiety every night,” his mother Lora Pournazarian told ABC News. “We go to sleep going, ‘We hope we don’t miss an alarm clock because he could die.’”

But Jonah’s parents aren’t the only ones looking out for him. His best friend from preschool, Dylan Siegel has his back, too.

Dr. David Weinstein, who studies and treats patients with glycogen storage disease at the University of Florida, was almost out of funding when he heard that Dylan wanted to help raise money to find a cure for the disease. Dylan was only 6 years old at the time, so Weinstein mostly just thought he was cute.

But Dylan had other plans. He wrote a book called “Chocolate Bar,” and explained to his parents “chocolate bar” means “awesome” to him. “Disneyland is so chocolate bar,” the book starts out. The last page says, “I like to help my friends. That is the biggest chocolate bar.”

Dylan’s project raised more than $750,000 in a little more than a year by selling the books for $20 each in all 50 states and 42 countries. Every cent goes to Weinstein’s lab.

“Boy, have I been shocked,” Weinstein told ABC News in September, when the book had crossed the $400,000 mark. “He’s raised more money for this disease than all the medical foundations and all the grants combined. Ever.”

When this story aired on ABC World News Wednesday night, “Chocolate Bar” had raised more than $500,000. Fewer than 24 hours later, it had raised an additional $250,000.

When asked where the two boys will be in 10 or 15 years, Dylan said, “High school, and probably his disease would be cured ’cause it’s not going to take like 15 years to be cured.”

That would be so chocolate bar.

http://abcnews.go.com/blogs/health/2014/02/27/boy-author-raises-750k-for-sick-friend/

Duck_chicken_penisRooster

Researchers have now unraveled the genetics behind why most male birds don’t have penises, just published in Current Biology.
[Ana Herrera et al, Developmental Basis of Phallus Reduction During Bird Evolution]

There are almost 10,000 species of birds and only around 3 percent of them have a penis. These include ducks, geese and swans, and large flightless birds like ostriches and emus. In fact, some ducks have helical penises that are longer than their entire bodies. But eagles, flamingos, penguins and albatrosses have completely lost their penises. So have wrens, gulls, cranes, owls, pigeons, hummingbirds and woodpeckers. Chickens still have penises, but barely—they’re tiny nubs that are no good for penetrating anything.

In all of these species, males still fertilise a female’s eggs by sending sperm into her body, but without any penetration. Instead, males and females just mush their genital openings together and he transfers sperm into her in a maneuver called the cloacal kiss.

To get to the root of this puzzle, researchers compared the embryos of chickens and ducks. Both types of birds start to develop a penis. But in chickens, the genital tubercle shrinks before the little guys hatch. And it’s because of a gene called Bmp4.

“There are lots of examples of animal groups that evolved penises, but I can think of only a bare handful that subsequently lost them,” says Diane Kelly from the University of Massachusetts in Amherst. “Ornithologists have tied themselves in knots trying to explain why an organ that gives males an obvious selective advantage in so many different animal species disappeared in most birds. But it’s hard to address a question on why something happens when you don’t know much about how it happens.”

That’s where Martin Cohn came in. He wanted to know the how. His team at the University of Florida studies how limbs and genitals develop across the animal kingdom, from the loss of legs in pythons to genital deformities in humans. “In a lab that thinks about genital development, one takes notice when a species that reproduces by internal fertilization lacks a penis,” says graduate student Ana Herrera.

By comparing the embryos of a Pekin duck and a domestic chicken, Herrera and other team members showed that their genitals start developing in the same way. A couple of small swellings fuse together into a stub called the genital tubercle, which gradually gets bigger over the first week or so. (The same process produces a mammal’s penis.)

In ducks, the genital tubercle keeps on growing into a long coiled penis, but in the chicken, it stops around day 9, while it’s still small. Why? Cohn expected to find that chickens are missing some critical molecule. Instead, his team found that all the right penis-growing genes are switched on in the chicken’s tubercle, and its cells are certainly capable of growing.

It never develops a full-blown penis because, at a certain point, its cells start committing mass suicide. This type of ‘programmed cell death’ occurs throughout the living world and helps to carve away unwanted body parts—for example, our hands have fingers because the cells between them die when we’re embryos. For the chicken, it means no penis. “It was surprising to learn that outgrowth fails not due to absence of a critical growth factor, but due to presence of a cell death factor,” says Cohn.

His team confirmed this pattern in other species, including an alligator (crocodilians are the closest living relatives of birds). In the greylag goose, emu and alligator, the tubercle continues growing into a penis, with very little cell death. In the quail, a member of the same order as chickens, the tubercle’s cells also experience a wave of death before the organ can get big.

This wave is driven by a protein called Bmp4, which is produced along the entire length of the chicken’s tubercle, but over much less of the duck’s. When Cohn’s team soaked up this protein, the tubercle’s cells stopped dying and carried on growing. So, it’s entirely possible for a chicken to grow a penis; it’s just that Bmp4 stops this from happening. Conversely, adding extra Bmp protein to a duck tubercle could stop it from growing into its full spiralling glory, forever fixing it as a chicken-esque stub.

Bmp proteins help to control the shape and size of many body parts. They’re behind the loss of wings in soldier ants and teeth of birds. Meanwhile, bats blocked these proteins to expand the membranes between their fingers and evolve wings.

They also affect the genitals of many animals. In ducks and geese, they create the urethra, a groove in the penis that sperm travels down (“If you think about it, that’s like having your urethra melt your penis,” says Kelly.) In mice, getting rid of the proteins that keep Bmp in check leads to tiny penises. Conversely, getting rid of the Bmp proteins leads to a grossly enlarged (and almost tumour-like) penis.

Penises have been lost several times in the evolution of birds. Cohn’s team have only compared two groups—the penis-less galliforms (chickens, quails and pheasants) and the penis-equipped anseriforms (swans, ducks and geese). What about the oldest group of birds—the ratites, like ostriches or emus? All of them have penises except for the kiwis, which lost theirs. And what about the largest bird group, the neoaves, which includes the vast majority of bird species? All of them are penis-less.

Maybe, all of these groups lost their penis in different ways. To find out, Herrera is now looking at how genitals develop in the neoaves. Other teams will no doubt follow suit. “The study will now allow us to more deeply explore other instances of penis loss and reduction in birds, to see whether there is more than one way to lose a penis,” says Patricia Brennan from the University of Massachussetts in Amherst.

And in at least one case, what was lost might have been regained. The cracids—an group of obscure South American galliforms—have penises unlike their chicken relatives. It might have been easy for them to re-evolve these body parts, since the galliforms still have all the genetic machinery for making a penis.

We now know how chickens lost their penises, but we don’t know why a male animal that needs to put sperm inside a female would lose the organ that makes this possible. Cohn’s study hints at one possibility—it could just be a side effect of other bodily changes. Bmp4 and other related proteins are involved in the evolution of many bird body parts, including the transition from scales to feathers, the loss of teeth, and variations in beak size. Perhaps one of these transformations changed the way Bmp4 is used in the genitals and led to shrinking penises.

There are many other possible explanations. Maybe a penis-less bird finds it easier to fly, runs a smaller risk of passing on sexually-transmitted infections, or is better at avoiding predators because he mates more quickly. Females might even be responsible. Male ducks often force themselves upon their females but birds without an obvious phallus can’t do that. They need the female’s cooperation in order to mate. So perhaps females started preferring males with smaller penises, so that they could exert more choice over whom fathered their chicks. Combinations of these explanations may be right, and different answers may apply to different groups.

Thanks to Dr. Lutter for bringing this to the It’s Interesting community.

http://www.oddly-even.com/2013/06/06/how-chickens-lost-their-penises-and-ducks-kept-theirs_/

http://news.yahoo.com/why-did-chicken-lose-penis-165408163.html

mars

A hardy bacteria common on Earth was surprisingly adaptive to Mars-like low pressure, cold and carbon dioxide-rich atmosphere, a finding that has implications in the search for extraterrestrial life.

The bacteria, known as Serratia liquefaciens, is found in human skin, hair and lungs, as well as in fish, aquatic systems, plant leaves and roots.

“It’s present in a wide range of medium-temperature ecological niches,” said microbiologist Andrew Schuerger, with the University of Florida.

Serratia liquefaciens most likely evolved at sea level, so it was surprising to find it could grow in an experiment chamber that reduced pressure down to a Mars-like 7 millibars, Schuerger said.

Sea-level atmospheric pressure on Earth is about 1,000 millibars or 1 bar.

“It was a really big surprise,” Schuerger said. “We had no reason to believe it was going to be able to grow at 7 millibars. It was just included in the study because we had cultures easily on hand and these species have been recovered from spacecraft.”

In addition to concerns that hitchhiking microbes could inadvertently contaminate Mars, the study opens the door to a wider variety of life forms with the potential to evolve indigenously.

To survive, however, the microbes would need to be shielded from the harsh ultraviolet radiation that blasts the surface of Mars, as well as have access to a source of water, organic carbon and nitrogen.

NASA’s Curiosity Mars rover is five months into a planned two-year mission to look for chemistry and environmental conditions that could have supported and preserved microbial life.

Scientists do not expect to find life at the rover’s landing site – a very dry, ancient impact basin called Gale Crater near the Martian equator. They are however hoping to learn if the planet most like Earth in the solar system has or ever had the ingredients for life by chemically analyzing rocks and soil in layers of sediment.

So far, efforts to find Earth microbes that could live in the harsh conditions of Mars have primarily focused on so-called extremophiles which are found only in extreme cold, dry or acidic environments on Earth. Two extremophiles tested along with the Serratia liquefaciens and 23 other common microbes did not survive the experiment.

A follow-up experiment on about 10,000 other microbes retrieved from boring 12 to 21 meters into the Siberian permafrost found six species that could grow in the simulated Mars chamber, located at the Space Life Sciences Laboratory adjacent to NASA’s Kennedy Space Center in Florida.

The next step is to see how the microbes fare under even more hostile conditions.

http://english.sina.com/culture/p/2013/0110/547474.html

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theta-function

While on his death bed, the brilliant Indian mathematician Srinivasa Ramanujan cryptically wrote down functions he said came to him in dreams, with a hunch about how they behaved. Now 100 years later, researchers say they’ve proved he was right.

“We’ve solved the problems from his last mysterious letters. For people who work in this area of math, the problem has been open for 90 years,” Emory University mathematician Ken Ono said.

Ramanujan, a self-taught mathematician born in a rural village in South India, spent so much time thinking about math that he flunked out of college in India twice, Ono said.

But he sent mathematicians letters describing his work, and one of the most preeminent ones, English mathematician G. H. Hardy, recognized the Indian boy’s genius and invited him to Cambridge University in England to study. While there, Ramanujan published more than 30 papers and was inducted into the Royal Society. [Creative Genius: The World’s Greatest Minds]

“For a brief window of time, five years, he lit the world of math on fire,” Ono told LiveScience.

But the cold weather eventually weakened Ramanujan’s health, and when he was dying, he went home to India.

It was on his deathbed in 1920 that he described mysterious functions that mimicked theta functions, or modular forms, in a letter to Hardy. Like trigonometric functions such as sine and cosine, theta functions have a repeating pattern, but the pattern is much more complex and subtle than a simple sine curve. Theta functions are also “super-symmetric,” meaning that if a specific type of mathematical function called a Moebius transformation is applied to the functions, they turn into themselves. Because they are so symmetric these theta functions are useful in many types of mathematics and physics, including string theory.

Ramanujan believed that 17 new functions he discovered were “mock modular forms” that looked like theta functions when written out as an infinte sum (their coefficients get large in the same way), but weren’t super-symmetric. Ramanujan, a devout Hindu, thought these patterns were revealed to him by the goddess Namagiri.

Ramanujan died before he could prove his hunch. But more than 90 years later, Ono and his team proved that these functions indeed mimicked modular forms, but don’t share their defining characteristics, such as super-symmetry.

The expansion of mock modular forms helps physicists compute the entropy, or level of disorder, of black holes.

In developing mock modular forms, Ramanujan was decades ahead of his time, Ono said; mathematicians only figured out which branch of math these equations belonged to in 2002.

“Ramanujan’s legacy, it turns out, is much more important than anything anyone would have guessed when Ramanujan died,” Ono said.

The findings were presented last month at the Ramanujan 125 conference at the University of Florida, ahead of the 125th anniversary of the mathematician’s birth on Dec. 22.

Read more: http://www.businessinsider.com/researchers-unlock-formula-mathematician-srinivasa-ramanujan-2012-12#ixzz2GTAEauqP

Thanks to Kebmodee for bringing this to the attention of the It’s Interesting community.