Monday, April 7, 2014

'Math detective' analyzes odds for suspicious lottery wins

Emory mathematician Skip Garibaldi (above in a classroom) helped do the math for a Palm Beach Post investigation of suspicious wins in the Florida Lottery. Garibaldi has since started eyeing data from the Georgia Lottery. (Emory Photo/Video)

By Carol Clark

When investigative reporter Lawrence Mower decided to dig into public records for the winners of the Florida Lottery, he noticed an intriguing pattern. Over a decade, a few names kept popping up as winners of all kinds of games. The most prolific of these winners, according to the lottery data, was a man who claimed an incredible 252 prizes during six years, for a total take of $719,000.

“If you’re winning like this in Las Vegas, they’re going to take you into a back room and find out how you’re cracking the game,” Mower said.

But when Mower asked a Florida lottery official about what seemed like a suspicious number of repeat wins by some players he was told that they could just be lucky.

Mower and his colleagues at the Palm Beach Post wanted to find out exactly how lucky these dominant players were, but they needed help calculating the odds.

“I starting looking for a mathematician who had dealt with odds and the lottery,” Mower says. “That’s how I found Skip.”

Skip Garibaldi, a professor in Emory’s Department of Mathematics and Computer Science and associate director of UCLA’s Institute for Pure and Applied Mathematics, was happy to work on the project.

“It was like a dream come true,” says Garibaldi, whose previous research on lotteries received the Lester R. Ford Award for mathematics and is the subject of a chapter in the popular book “Brain Trust” by Garth Sundem. Garibaldi enjoys breaking down complex math for the general public and has appeared on 20/20, CNN and Fox & Friends.

“I get this call from Lawrence, and he says, ‘I have this huge database I’d like to feed you of everyone who has won more than a $600 prize in the Florida Lottery over a decade,” Garibaldi recalls.

Philip Stark, a statistician from the University of California, Berkeley, and Richard Arratia, a probabilist from the University of Southern California, were also recruited to work with Garibaldi on the project. The three mathematicians are now writing an academic paper that will explain their lottery findings in more technical detail.

Watch a video on the lottery investigation:



Two of the underlying principles for the lottery analysis were probability theory and the law of large numbers, which both trace their beginnings to a 16th-century Italian mathematician, Gerolamo Cardano. In fact, it was his love of dice games and other forms of gambling that sparked Cardano to work on probability questions.

“The subtle point about probability or quantum mechanics,” Garibaldi says, “is that there are things that we know are possible and we can calculate the probability of them happening, but they are so unlikely that no one has seen them happen and likely no one ever will. For this lottery question, something that happens to fewer than one-in-20-trillion lottery gamblers is one of these utterly implausible events.” 

Using this generous bar for random luck, the analysis identified winners who were defying the odds during the past decade, and would have had to lose prodigious amounts of money to win so many times. The most prolific winner, for instance, would have had to spend an estimated minimum of $2.07 million to have a one-in-20-trillion shot at his 252 wins and winnings of $719,051, for a net loss of about $2.35 million.

“But even if every single citizen in the state of Florida spent $2 million on lottery tickets,” Garibaldi says, “the odds are less than one in a million that anybody would have won that many times.”

These kinds of figures “put us in pretty safe territory with our suspicions that something was amiss,” Garibaldi says.

The mathematical analysis was also able to identify winners of multiple prizes who appeared to be legitimate gamblers. “The fact that a person claims multiple prizes does not necessarily indicate that they are doing anything suspicious,” Garibaldi says. “A finer analysis and more inspection can show that some people are likely just spending a lot of money on tickets and occasionally getting lucky.”

“The math was the critical part of this story,” Mower says of the package of investigative pieces published on Sunday, March 30. “It’s been really valuable working with Skip because he’ll see something that I won’t.”

On Monday, March 31, the state legislature called for more oversight of the Florida Lottery. On Tuesday, the lottery announced that it would adopt safeguards, such as software to track frequent winners. By Wednesday, lottery officials began raiding stores and seizing lottery equipment associated with some of the top prize winners. (Six of the 10 top winners in the lottery records were store clerks and owners who sold lottery tickets.)

Meanwhile, Garibaldi started eyeing data for winners of the Georgia Lottery. “The data from the Georgia Lottery is not as good as from Florida, because Georgia only lists winners for prizes of $5,000 or more,” he says. “But just casually looking at the Georgia data since 2003, I see what may be suspicious numbers for repeat winners.”

Related:
Lottery study zeroes in on risk
Mathematicians add logic to the lottery
How culture shaped a mathematician

Sunday, April 6, 2014

Seeing the tropical forest amid disease

"Insights over the past three decades have clarified how the health and persistence of tropical forest systems depend on critical ecosystem services provided by wildlife," Emory disease ecologist Thomas Gillespie told Liz Kimbrough in a recent intreview for the conservation news site Mongabay. "We've lost pollinators—honeycreeper declines in Hawaii due to introduced malaria; seed dispersers—lowland gorilla declines due to Ebola; and indicator species—frog declines and extinctions due to chytrid fungus."

Gillespie at work in Uganda
Gillespie, an associate professor in Emory's Department of Environmental Sciences and the Rollins School of Public Health, was featured as one of the 12 top innovators in tropical conservation. Below is an excerpt from the interview:

Mongabay: What's the next big thing in forest conservation? What approaches or ideas are emerging or have recently emerged? What will be the catalyst for the next big breakthrough?

Thomas Gillespie: In the past decade, technological advances in non-invasive pathogen surveillance have allowed us to make great strides in understanding how infectious diseases may threaten endangered species (i.e., fecal assays to examine respiratory pathogens and blood-borne pathogens like malaria and immunodeficiency viruses). Similarly, an exciting innovation that's just taking off is letting mosquitos, leeches, and carrion flies do the work for us! All of these invertebrates seek out wildlife for a meal. By trapping them and analyzing their gut contents, we can determine which wildlife species they fed on, and in some cases, the pathogens that infected those individuals. This is especially interesting in regards to carrion flies, since they feed more or less indiscriminately on dead or dying animals. As a result, screening large numbers of carrion flies in a selected tropical forests could provide an inventory of faunal and pathogen diversity including data on the presence or absence of cryptic species. In addition, this method may alert wildlife managers to major mortality events (i.e., based on anomalies in the frequency and amount of DNA from a specific vertebrate species being recovered).

Read the whole interview at mongabay.com.

Related:
In Madagascar, a health crisis of people and their ecosystem
Primate disease ecologist tracks germs in the wild
How germs jump species

Friday, April 4, 2014

Dengue study to focus on asymptomatic carriers

A NASA satellite image shows the metropolitan area of Iquitos, Peru, nestled in the Amazon Basin, on the banks of the Amazon River (lower left) and surrounded by smaller rivers, lakes and lagoons.

By Carol Clark

Dengue fever is a leading cause of illness and death in the tropics and subtropics, infecting as many as 400 million people annually, according to the CDC.

“Currently, the most effective way to control dengue outbreaks is to spray for mosquitoes and help people to avoid getting bit by them,” says Gonzalo Vazquez-Prokopec, a disease ecologist in Emory’s Department of Environmental Sciences.

Vazquez-Prokopec is a co-principal investigator on a major dengue research project ongoing in Iquitos, Peru, which is honing in on ways to control outbreaks of the disease and more effectively treat infections. The National Institutes of Health recently awarded $7 million to the project team, led by the University of California, Davis, and also including the U.S. Navy, North Carolina State University, the University of Iowa, Tulane University and San Diego State.

Emory’s portion of the grant – $1.3 million – will be used to study how people who are infected with a dengue virus, but not showing symptoms, may contribute to the spread of dengue.

Infections can spread like wildlife through urban areas of the developing world where many people live in close quarters in substandard housing. Mosquitoes are the vectors of the disease, transmitting the four viruses that cause dengue between people.

“It’s a complex disease, made even more complicated by the fact that four different species of dengue viruses can interact with one another,” Vazquez-Prokopec says. “And yet, we actually know more about these viruses than we do about the behaviors of the people who get infected with them.”

The Emory research team also includes Uriel Kitron, chair of Emory’s Department of Environmental Sciences, and Lance Waller, chair of the Department of Biostatistics and Bioinformatics at the Rollins School of Public Health.

Dengue is endemic in Iquitos, a city on the edge of the Amazon rainforest. A large portion of people who get infected do not experience the usual debilitating symptoms of dengue and continue going to work or visiting friends and relatives.

“We want to determine if these people are significant spreaders of the disease,” Vazquez-Prokopec says.

The experiment will require participants to undergo blood tests and wear a device that uses a GPS to track their movements and a body temperature monitor to record any bouts of fever. The data from asymptomatic people who are infected will be analyzed along with spatial-temporal data on infected people who become sick during an outbreak. Ultimately, the project will infer the contribution of asymptomatic people by linking those data with mathematical models simulating virus spread within the city.

For an earlier phase of the research project, Emory post-doc Donal Bisanzio created a data visualization, above, of the movement routines of people in Iquitos.

Previously, Vazquez-Prokopec and colleagues used GPS technology to quantify the movement and contact dynamics of nearly 600 residents of Iquitos, where most people are self-employed or hold several jobs to try and make ends meet. The results showed that the participants visited an average of six locations per day overall, compared to cities in North America and Europe where urbanites visit an average of two to four locations daily.

The researchers have also conducted spatial-temporal analyses of dengue outbreak patterns through two large neighborhoods of Iquitos. When a case of dengue was confirmed through a blood test, social workers would interview the patient, recording all the places he patient went during the 15 days leading up to the onset of fever. That study found that one of the main drivers for infection was people visiting friends and relatives in nearby homes, as opposed to large gathering places like schools.

“This large project will shed light onto something that hasn’t been explored before: The role of people who are undetected by the health system in propagating dengue,” says Vazquez-Prokopec.

Related:
How the dengue virus makes a home in the city
Human mobility data may help curb urban epidemics

Sharing the 'wow' of science

Emory chemist Doug Mulford blows a fireball at the Atlanta Science Festival expo March 29. Emory Photo/Video.

By Megan Terraso, Emory Report

Rows of children sat with rapt attention, their mouths agape at what they were seeing at the Atlanta Science Festival.

"That look of wonder is why we do it," says Douglas Mulford, director of undergraduate studies of chemistry and senior lecturer at Emory. "We wanted to show the 'wow' of science and show how fascinating it can be."

Mulford was one of many Emory faculty, staff and students who participated in 25 Emory demonstrations and exhibits at the Atlanta Science Festival March 22-29. The massive weeklong festival included more than 100 events at nearly 35 venues and everything from tours and film screenings to trivia nights and flashy science demonstrations.

At the festival's science expo March 29 at the Georgia World Congress Center, Mulford and several Emory students put on a science stage show with bubbling beakers and exploding balloons to a packed room with an audience of around 1,000.

Mulford also oversaw the very popular "cornstarch dance pit," a three foot by three foot pit where visitors could dance or sink in the cornstarch and water mix. "As long as you dance, you stay up. When you stop, you sink. That was a lot of fun," Mulford says.

Other Emory exhibits at the expo, which attracted tens of thousands of visitors, included monarch butterflies, the opportunity to touch a real brain and a booth that allowed visitors to swab the bottom of their shoe or their ear and follow the growth of the bacteria they'd swabbed over a few hours or days via a website.

Read more at Emory Report.

Monday, March 31, 2014

For the love of lemurs and Madagascar

The IMAX movie “Island of Lemurs: Madagascar” opens nationwide on April 4, including Atlanta's Fernbank Museum of Natural History. Brown mouse lemurs, above, are among those featured in the film about the island, a bio-diversity hotspot.  (Photo by Sarah Zohdy.)

By Carol Clark

“I smell props,” says Sarah Zohdy, a biologist in Emory’s Department of Environmental Sciences and the Rollins School of Public Health. She looks skyward, scanning a tangle of thick Tarzan vines, tree branches and leaves that weave the dense rainforest canopy 100 feet above.

“Do you smell that?” Zohdy asks a new arrival to Madagascar’s Ranomafana National Park. “They have a scent like maple syrup.”

Then, whoosh! A wide-eyed, fur-covered acrobat, mostly arms, legs and tail, leaps out of one clump of leaves and disappears into another.

“Props!” Zohdy confirms, smiling at the comical effect of the creature. “Their legs are crazy long for their bodies.”

Propithecus edwardsi
Propithecus edwardsi, more commonly known as a sifaka, is one of nearly a hundred species of lemurs. These primitive primates, with large, round eyes and wet, dog-like noses, are unique to Madagascar, an island in the Indian Ocean, off the southeast coast of Africa.

Lemur ancestors arrived in Madagascar some 65 million years ago, perhaps floating over from mainland Africa on mats of vegetation. Isolated on the island, the Earth’s fourth largest, lemurs evolved independently from other primates, diverging into a striking cast of characters: From the teddy-bear cute black-and-white ruffed lemur to the creepy, bat-like aye-aye.

Zohdy’s favorite is the mouse lemur, the smallest primate in the world. “The adults weigh about as much as a fun-sized package of M&Ms and can fit into the palm of your hand,” she says. “The babies are no bigger than a Ping-Pong ball and, basically, all eyeballs.”

A new IMAX movie “Island of Lemurs: Madagascar,” opening nationwide on April 4, features the work in Ranomafana of famed primatologist Patricia Wright, one of Zohdy’s mentors. “The imagery in the film is so rich, it tugs on my heartstrings,” Zohdy says. “I hope the film makes more people around the world aware of the dire ecological situation in Madagascar.”

Watch the trailer for the IMAX movie:


Zohdy has been researching lemurs in Madagascar for seven years. Last summer, she broadened her focus and led an Emory infectious disease field team in Ranomafana, made up of students from a range of specialties. The Emory team is gathering baseline data for an ambitious “one health” intervention. The goal is to bolster the health of the rural poor around Ranomafana, who are struggling to stay fed, sheltered and alive, while also conserving the ecosystem of the World Heritage site.

Zohdy’s rubber boots make loud sucking sounds as she trudges through thick mud towards a wooden suspension bridge spanning the Namorona River, roaring and rushing over its rocky bed even during the dry season.

“Check out that spider web,” she says, as she leads the way across the bridge. She points up at gossamer threads hanging above the water, leading out of the forest on one side of the river and stretching 40 feet to connect with the trees on the opposite bank. The recently discovered Darwin’s bark spider, she notes, spins the largest webs in the world, and its silk is the toughest biological material ever studied, more than 10 times tougher than Kevlar.

Crested drongos – large black birds sporting what look like elegant coattails and fancy feather headdresses – chatter in the trees alongside the slick forest trail, which is now leading steeply up a lush hillside.

Zohdy pauses when she hears breaking leaves in the canopy and catches a whiff of a musky, zoo-like smell. “Golden bamboo lemurs. They are right above us,” she says softly. “Don’t open your mouth when you look up,” she quickly adds. “People have been peed on.”

A golden bamboo lemur, photographed in Ranomafana by Sarah Zohdy.

The dusky-gold creatures, which look like a cross between a Koala bear and a raccoon, are critically endangered. They are one of three species of lemurs in the park that subsist almost entirely on the tender leaves and shoots of bamboo.

The greater bamboo lemur is the rarest of them all. Just two remain in the 160-square-mile Ranomafana National Park – a father and his daughter – and only about 60 survive in the wild. Like the giant panda, the greater bamboo lemur has molars capable of slicing and crushing the tough trunk of bamboo.

“It’s a fascinating evolutionary adaption,” Zohdy says, that allows them to survive during the dry season, when the more tender bamboo shoots and leaves are not as readily available. Loss of habitat and shifts in climate, however, have lengthened the dry season. “That means the greater bamboo lemurs have to chew on the tough trunks longer, which wears down their teeth,” Zohdy says. “When their teeth go bad, they starve. It’s not like they can go to a bamboo lemur dentist and get dentures.”

Since humans began settling on the island, only about 2,000 years ago, bringing a rice-growing culture with them, much of the natural habitat and its wildlife has disappeared, including at least 17 species of lemurs.

“When I first came to Madagascar, I thought the whole island would look like a BBC nature special,” Zohdy recalls. Instead she was stunned during the ten-hour drive from the capital of Antananarivo to Ranomafana to see a largely treeless landscape of terraced rice paddies and the occasional smoke from slash-and-burn agriculture.

Watch a video about an Emory "one-health" project in Madagascar:


In the steep landscape of Ranomafana, the homes of villagers and their food crops and livestock bump up against the remaining patches of primordial wilderness. The crowding puts both people and animals at risk. “When you have humans encroaching on wildlife habitat you have huge potential for zoonotic diseases, and the emergence of new diseases,” Zohdy says. Pneumonic plague and virulent strains of flu are examples of deadly outbreaks that have occurred in Madagascar in recent years.

The “one health” approach of the Emory infectious disease team may be key to solving some of the complex problems facing the Malagasy people and the fragile Ranomafana ecosystem. “To really understand human health, animal health, and environmental health, you have to study all three at once,” Zohdy says.

During the summers, going back to 2011, Emory student-researchers have collected fecal samples of lemurs, people and their livestock. These samples, along with mosquitos and ticks the team is collecting, are sent back to Atlanta for analysis of pathogens they may contain.

The project is part of a large-scale effort of conservation and global health being coordinated by Thomas Gillespie, an Emory professor of Environmental Sciences and Environmental Health. The data the students are gathering will help guide a health care improvement effort through a new non-profit agency called PIVOT.

Madagascar is home to half the world's chameleon species. Photo by Sarah Zohdy.

One evening, Zohdy leads students on the team on a night-time expedition up the side of a mountain to check on some of her live traps for mouse lemurs. The dark forest is eerily silent and still. A thick mist snakes along the ground and drifts up through the silhouettes of trees.

The researchers’ headlamps slice like lasers across the understory, occasionally striking treasure. An iridescent green and blue chameleon looks like a jeweled dragon clinging to the branch of a sapling. A golden moth, the size of a small bird, fans its wings across a clump of eucalyptus leaves.

“Do you hear that high-pitched trill, like a tiny, far-away bell?” Zohdy asks. “That’s a mouse lemur.”

Tiny pairs of glowing eyes pop out of the darkness along either side of the trail. Mouse lemurs are nocturnal and their eyes shine like those of cats. The eyes appear, then vanish in a flash, as the curious but shy creatures dart like birds, or fairies, amid the branches of small trees.

The team arrives at the first trap, a metal contraption about half the size of a shoebox. It is occupied. Zohdy instructs everyone to switch their head lamps from white light to red, so the lemur does not get blinded. She gloves up and slowly opens the door to the trap and reaches in to gently retrieve a brown mouse lemur. First she slips it into a cloth sack to weigh it on a tiny scale: 2.9 ounces. Then she takes a fecal sample, and checks its genitals.

Watch a video about the making of the IMAX movie:


“It’s a male,” she pronounces. “His testicles are starting to show, he’s getting ready to breed in a few months.”

Mouse lemurs mate just one day of the year, an all-or-nothing enterprise. “When their testicles fully distend, they can get as big as their head,” Zohdy says. “I’ve seen their balls get caught in the V of branches when they jump.”

The females, however, generally have higher levels of testosterone and dominate the males. “Everything about mouse lemurs is weird,” Zohdy says.

This night’s captive is particularly docile.

Cassidy Rist, a veterinarian enrolled in Emory’s masters in public health program, puts on gloves and scruffs the lemur’s neck with her thumb and forefinger, letting its body rest in the cupped palm of her free hand. Bathed in the red glow of the headlamps, the mouse lemur does not struggle, although its wide, round eyes give it a look of intense surprise.

Another student slips on a glove and extends a hand towards the creature. The lemur does not hesitate to grip the tip of her index finger. Its hand is about the size of a dime, and looks more human than animal, complete with delicate fingernails. The lemur looks up, staring straight into her eyes with wonder, like a mirror of the student's own awe at this otherworldly encounter.

Related:
In Madagascar: A health crisis of people and their ecosystem