New study first to directly measure body temperatures of extinct species

A new study by researchers from five institutions including the University of Florida introduces the first method to directly measure body temperatures of extinct vertebrates and help reconstruct temperatures of ancient environments.

The study, appearing in this week’s online early edition of Proceedings of the National Academy of Sciences, describes how scientists could use carbon and oxygen isotopes from fossils to more accurately determine whether extinct animals were warm-blooded or cold-blooded and better estimate temperature ranges during the times these animals lived.

“Without a time machine, it has previously been impossible to directly take the temperature of extinct animals such as dinosaurs or megalodon sharks,” said study co-author Richard Hulbert, a vertebrate paleontologist at the Florida Museum of Natural History on the UF campus. “The method described in the study has been shown to work with 12-million-year-old fossils from Florida and the next step is to look at even older fossils. For example, we have no teeth of Titanoboa, the largest snake ever discovered, but we could use 60-million-year-old crocodylian teeth from the same deposit to find out more about the snake’s environment.”

Funded in part by the National Science Foundation, the new “clumped-isotope” paleothermometer method used in the study analyzes two rare heavy isotopes, carbon-13 and oxygen-18, found in tooth enamel, bones and eggshells.

“Clumping is temperature dependent, so at low temperatures you get more clumping together in a mineral while high temperatures mean less clumping,” said lead author and California Institute of Technology postdoctoral scholar Robert Eagle. “If you can measure the clumping accurately enough, you can work out the temperature at which a mineral formed. In the case of teeth and bone, this will be the body temperature of the organism.”

The researchers first tested the method on modern species: the white rhinoceros, Indian elephant, Nile crocodile, American alligator and sand tiger shark. The study confirmed the rhinoceros and elephant, like all mammals, are warm-blooded, and their tooth enamel forms at about 37 degrees Celsius. Researchers confirmed the accuracy within 2 degrees Celsius by measuring teeth of modern sharks from temperature-controlled aquariums. In the next stage of the study, researchers tested fossils of mammoths and older extinct Florida alligator and rhinoceros species.

“The method we present is a big advance because it allows a direct measurement of the body temperature of extinct species, free from the assumptions required with other approaches,” Eagle said. …

via University of Florida News – New study first to directly measure body temperatures of extinct species.

Deadly, ultra-pure heroin arrives in US

In this April 22, 2010 photo, Sue Tayon poses for a photo in her home holding an urn containing her daughter Nikki Tayon’s ashes in Overland, Mo. Tayon’s 28-year-old daughter, Nikki, died of an overdose on heroin that was 90 percent pure, her mother said. (AP Photo/Jeff Roberson)

Mexican drug smugglers are increasingly peddling a form of ultra-potent heroin that sells for as little as $10 a bag and is so pure it can kill unsuspecting users instantly, sometimes before they even remove the syringe from their veins.

An Associated Press review of drug overdose data shows that so-called “black tar” heroin – named for its dark, gooey consistency – and other forms of the drug are contributing to a spike in overdose deaths across the nation and attracting a new generation of users who are caught off guard by its potency.

“We found people who snorted it lying face-down with the straw lying next to them,” said Patrick O’Neil, coroner in suburban Chicago’s Will County, where annual heroin deaths have nearly tripled – from 10 to 29 – since 2006. “It’s so potent that we occasionally find the needle in the arm at the death scene.”

Authorities are concerned that the potency and price of the heroin from Mexico and Colombia could widen the drug’s appeal, just as crack did for cocaine decades ago.

The Latin American heroin comes in the form of black tar or brown powder, and it has proven especially popular in rural and suburban areas.

Originally associated with rock stars, hippies and inner-city junkies, heroin in the 1970s was usually smuggled from Asia and the Middle East and was around 5 percent pure. The rest was “filler” such as sugar, starch, powdered milk, even brick dust. The low potency meant that many users injected the drug to maximize the effect.

But in recent years, Mexican drug dealers have improved the way they process poppies, the brightly colored flowers supplied by drug farmers that provide the raw ingredients for heroin, opium and painkillers such as morphine. Purity levels have increased, and prices have fallen.

Federal agents now commonly find heroin that is 50 percent pure and sometimes as much as 80 percent pure.

The greater potency allows more heroin users to snort the drug or smoke it and still achieve a sustained high – an attractive alternative for teenagers and suburbanites who don’t want the HIV risk or the track marks on their arms that come with repeated injections. …

via The Galveston County Daily News.

Google’s Pac-Man Tribute: Bad for Business?

Pac-Man, a video game hero from the early 1980s, got a major publicity boost last weekend when Google placed a fully-functional version of the classic arcade hit on its home page. The tribute was in honor of Pac-Man’s 30th anniversary.

Great, so millions of people spent their precious weekend minutes (hours?) maneuvering a maze and gobbling up pac-dots. Problem is, their Pac-Man addiction may have crossed over into the workplace too.

The RescueTime Blog did some quick calculations over the weekend to quantify just how much productivity was lost as a result of workers engaged in Pac-Man rather than their jobs. (RescueTime is a monitoring app for businesses that tracks which software and websites their employees use.)

The RescueTime folks took a random sample of its users–about 11,000 people who spent some “3 million seconds” on Google on Friday May 21, the day the playable Pac-Man logo appeared. They determined that 4.82 million hours of valuable work time were frittered away on Blinky, Pinky, Inky, and Clyde.

Here’s the breakdown from RescueTime’s Tony Wright:

· The average user spent 36 seconds more than usual on Google.com on Friday.

· Google Pac-Man consumed 4,819,352 hours of time.

· Lost productivity totaled $120,483,800, assuming the average Google user has a cost of $25/hour.

· That $120 million is enough to pay all 19,835 Google employees for 6 weeks. …

via Google’s Pac-Man Tribute: Bad for Business? – PCWorld.

You can play here, but do it on your own time: http://www.google.com/pacman

Mobile phone number suspended after three users die in 10 years

A mobile phone company has suspended the number 0888 888 888 – after every single person assigned to it died in the last 10 years.

The first owner Vladimir Grashnov – the former CEO of Bulgarian mobile phone company Mobitel which issued the number – died of cancer in 2001 aged just 48.

Despite a spotless business record there were persistent rumours that his cancer had been caused by a business rival using radioactive poisoning.

The number then passed to Bulgarian mafia boss, Konstantin Dimitrov, who was gunned down in 2003 by a lone assassin in the Netherlands during a trip to inspect his £500 million drug smuggling empire.

Dimitrov, who died aged 31, had the mobile with him when he was shot while eating out with a model.

Russian mafia bosses – jealous of his drug smuggling operation – were said to have been behind the killing.

The phone number then passed to Konstantin Dishliev, a crooked businessman, who was gunned down outside an Indian restaurant in Bulgaria’s capital Sofia after taking over the jinxed line.

Dishliev, an estate agent, had secretly been running a massive cocaine trafficking operation before his assassination in 2005.

He died after £130 million of the drug was intercepted by police on its way into the country from Colombia.

Since then, the number is understood to have been dormant while police maintained an open file on Dishliev’s killing and his smuggling ring.

Now phone bosses are said to have suspended the number for good. Callers now get a recorded message saying the phone is “outside network coverage.”

A Mobitel spokesman would only say: “We have no comment to make. We won’t discuss individual numbers.”

via Mobile phone number suspended after three users die in 10 years – Telegraph.

Navy drops buoy on Florida house

A sonar buoy from a Navy plane on a training flight crashed through the roof of a north Florida home.

Officials say the P-3 Orion had just taken off from Jacksonville Naval Air Station Friday morning when the 3-foot-long, 40-pound cylinder fell more than 500 feet.

The device went through the roof of a Mandarin house, landing next to a bed. Resident Marwan Saman says his daughter had just gotten out of that bed about a half hour earlier.

The Navy sent an explosives demolition team to retrieve the buoy. No injuries were reported, and the Navy was making arrangements to pay for the damage.

A P-3 can carry dozens of the devices to help track submarines. It’s possible a malfunctioning launch tube caused the plane to drop a buoy Friday morning.

via Navy drops buoy on Florida house | navy, buoy, drops – News – Northwest Florida Daily News.

Mind if the US Navy drops in? So, are these buoys explosive? I guess they just sent the explosives team because they don’t really have a buoy retrieval from a girl’s bedroom team.

Study sheds light into the nature of embryonic stem cells

New insight into what stem cells are and how they behave could help scientists to grow cells that form different tissues.

A study at the University of Edinburgh has shown that embryonic stem cells consist of cells that switch back and forth between precursors of different cell types. This may be linked to their potential to become any cell type in the body.

The findings could help scientists catch embryonic stem cells at exactly the right point when they are primed to differentiate into cells that form specific tissues.

The study indicates that embryonic stem cells are not a single cell type as previously thought, but comprise a mixture of different cell types from the early embryo that can transform themselves from one type to another.

Scientists previously thought that embryonic stem cells were only able to become the embryonic precursors for adult cells, a property known as pluripotency.

The researchers have now found that they can also turn into cells associated with the placenta. These cells – known as the primitive endoderm – form the yolk sac that helps provide nutrients to the early embryo.

The study, published in the journal PLoS Biology, also shows that embryonic stem cells are able to alternate and transform themselves between cells that create the primitive endoderm and founder embryonic cells, which will go onto form tissues in the body.

Although cells in early embryonic development switch back and forth between these two different cells, signals received from surrounding cells and the embryonic environment allow them to quickly fix on becoming one specific cell type.

However, in the laboratory embryonic stem cells are grown in a dish away from the embryo and as a result exist in a captured state where their identity does not become fixed.

Scientists hope that better understanding of how embryonic stem cells change will enable them create an environment to encourage growth of specific cells.

Dr Josh Brickman, from the University’s Medical Research Council Centre for Regenerative Medicine, said: “This study changes our view of what embryonic stem cells are and how they behave. Knowing that embryonic stem cells can switch between different founder cell types could help us isolate cells at a point in time when they are primed to become specific cells. This could improve the ability to produce specific cells in the laboratory.”

via Study sheds light into the nature of embryonic stem cells.

Visually-guided laser may be viable treatment for abnormal heartbeat

A new treatment known as a visually-guided laser-balloon catheter successfully interrupted abnormal electrical pulses in patients and pigs with intermittent, irregular heartbeats, in a study reported in Circulation: Arrhythmia and Electrophysiology, a journal of the American Heart Association.

Severe cases of irregular heartbeat may require a procedure called ablation, which destroys a group of “misfiring” cells to stop abnormal electrical impulses that cause erratic heartbeats.

Investigators aimed at cells in the pulmonary veins that carry blood from the lungs to the heart. In the clinical part of the study, they ablated the misfiring cells with 100 percent accuracy. In 84 percent of the pulmonary veins treated, electrical pulses ceased after just one set of laser treatments. Three months after treatment, 90 percent of the treated veins remained inactive.

Unlike other catheters that rely on X-rays for visual guidance, in the new treatment doctors use a slender instrument called an endoscope that provides continuous real-time images. This allows investigators to aim the laser at precise locations in the pulmonary veins. The investigators destroyed cells in an overlapping pattern to completely “disconnect” them and prevent new electrical connections from forming later.

The study’s clinical component included 27 patients, average age 53, two-thirds male, with diagnosed intermittent, abnormal heartbeat (called paroxysmal atrial fibrillation, or PAF). All patients had tried at least one drug that did not relieve their symptoms.

For the animal model, the scientists examined pigs because their hearts are structured similar to humans. The investigators inactivated abnormally functioning pulmonary veins 97 percent of the time after the first set of laser-energy treatments. Four weeks later, 80 percent of the ablated veins were still inactive.

Additional research is needed to determine long-term safety and efficacy of balloon-guided, laser catheter, researchers said.

via Visually-guided laser may be viable treatment for abnormal heartbeat.

Dangerous lung worms found in people who eat raw crayfish

If you’re headed to a freshwater stream this summer and a friend dares you to eat a raw crayfish – don’t do it. You could end up in the hospital with a severe parasitic infection.

Physicians at Washington University School of Medicine in St. Louis have diagnosed a rare parasitic infection in six people who had consumed raw crayfish from streams and rivers in Missouri. The cases occurred over the past three years, but three have been diagnosed since last September; the latest in April. Before these six, only seven such cases had ever been reported in North America, where the parasite, Paragonimus kellicotti, is common in crayfish.

“The infection, called paragonimiasis, is very rare, so it’s extremely unusual to see this many cases in one medical center in a relatively short period of time,” says Washington University infectious diseases specialist Gary Weil, MD, professor of medicine and of molecular microbiology, who treated some of the patients. “We are almost certain there are other people out there with the infection who haven’t been diagnosed. That’s why we want to get the word out.”

Paragonimiasis causes fever, cough, chest pain, shortness of breath and extreme fatigue. The infection is generally not fatal, and it is easily treated if properly diagnosed. But the illness is so unusual that most doctors are not aware of it. Most of the patients had received multiple treatments for pneumonia and undergone invasive procedures before they were referred to Barnes-Jewish Hospital or St. Louis Children’s Hospital at Washington University Medical Center.

The half-inch, oval-shaped parasitic worms at the root of the infection primarily travel from the intestine to the lungs. They also can migrate to the brain, causing severe headaches or vision problems, or under the skin, appearing as small, moving nodules.

Some of the patients had been in and out of the hospital for months as physicians tried to diagnose their mysterious illness and treat their symptoms, which also included a buildup of fluid around the lungs and around the heart. One patient even had his gallbladder removed, to no avail.

“Some of these invasive procedures could have been avoided if the patients had received a prompt diagnosis,” says Michael Lane, MD, an infectious diseases fellow at the School of Medicine who treated some of the patients. “We hope more doctors will now have this infection on their radar screens for patients with an unexplained lingering fever, cough and fatigue.”

Once the diagnosis is made, paragonimiasis is easily treated with an oral drug, praziquantel, taken three times a day for only two days. Symptoms begin to improve within a few days and are typically gone within seven to 10 days. All the patients have completely recovered, even one patient who temporarily lost his vision when parasites invaded the brain.  …

via Dangerous lung worms found in people who eat raw crayfish.

Meltdown: Why ice ages don’t last forever

BACK in 1993, a boy playing football near Nanjing, China, suddenly fell through the ground. He had inadvertently found a new cave, later named Hulu, which has turned out to be a scientific treasure chest. Besides two Homo erectus skeletons, it contains stalagmites that have helped solve one of the greatest mysteries in climate science: why the ice ages came and went when they did.

For more than 2 million years, Earth’s climate has been oscillating wildly. Immense ice sheets slowly advance across northern lands, then suddenly melt away to leave the planet basking in a relatively brief period of warmth before the ice creeps back again. Climate scientists have long suspected that these glacial cycles are triggered by changes in our planet’s orbit. Yet while this theory has had many successes, it fails to explain one critical fact: why the ice ages end every 100,000 years or so. “It’s a big problem,” says Larry Edwards of the University of Minnesota in Minneapolis.

Edwards is part of a group of researchers who may finally have the answer, thanks to Hulu and other nearby caves. If their conclusions are right, then the greatest ice sheets of the past were remarkably vulnerable, melting away when there was just a glimmer of extra sunlight.

…

This was far from the end of the story, though. We now know that the polar ice caps started to form around 30 million years ago, as carbon dioxide levels fell. Around 2.5 million years ago, as it got colder still, a cycle began in which more extensive ice sheets repeatedly spread across the northern hemisphere and then retreated. At first, these ice ages were relatively minor and occurred roughly every 41,000 years – just as you would expect based on the changing tilt of Earth’s axis.

But then, a little less than a million years ago, the pattern changed. A series of much more severe ice ages began that lasted 100,000 years. That is a big mystery, because although the shape of the Earth’s orbit alters slightly over periods of 95,000 and 125,000 years, this has a far weaker effect on the seasons than the other orbital cycles. Why would the deepest ice ages be driven by the smallest changes in summer sunshine?

Faced with this conundrum, some researchers began to explore alternatives to the mainstream orbital theory. One idea is that Earth sometimes passes through interplanetary dust clouds that cut off some of the sun’s heat. Or perhaps our star could be periodically getting brighter and dimmer.

Studies of ice cores from Antarctica, however, were starting to point in a different direction. The cores showed there was a close correlation between temperature and the levels of greenhouse gases in the atmosphere. This suggested a partial answer to the 100,000-year problem: small changes in sunshine might be greatly amplified by rises in CO₂ levels. But there was too much uncertainty about the timing of events to say what caused what.

To find out what really happened, researchers need accurate dates, especially for the ends of the ice ages. “I’ve been after the timing of these terminations for 25 years,” says Edwards. While marine sediments and ice cores record the sequence of events, it is difficult to date those events precisely. …

The stalagmites hold indirect clues to the climate in the form of oxygen isotopes, which record the strength of the summer monsoon. Water containing heavy oxygen condenses more easily, so the moisture-laden air of the monsoon loses most of its oxygen-18 as it moves inland. By the time it reaches central China, the rains are low in oxygen-18, and the stalagmites there record this depletion. But as the last ice age was ending, 11,000 to 17,000 years ago, the oxygen-18 content of the stalagmites increased – a sign that summer monsoon rains were much weaker than usual.

Wang then went looking for a cave with older stalagmites. He struck lucky at nearby Linzhu cave, despite a rather unusual hazard. “Bats stole our guide rope,” says Wang. “The cave has many branches, and we lost our way out.” When his team did eventually escape, around midnight, they brought out samples that held a much longer climate record. And stalagmites from another nearby cave called Sanbao provided even more precise dates.

… the new evidence points to a coherent story. Ice sheets build up until they near the brink of stability, at which point a modest rise in summer sunshine is enough to tip them over the edge. As the ice sheets melt, fresh water is released into the Atlantic, shutting down ocean circulation and pumping CO₂ into the atmosphere. As long as the combined effect of extra summer sunshine and rising CO₂ outweighs the regional cooling produced by the shutdown of ocean circulation, the ice keeps melting, pouring more fresh water into the Atlantic. And the melting of a really large ice sheet keeps ocean circulation shut down for a long time, eventually pumping so much CO₂ into the atmosphere that the ice sheets melt away in just a few thousand years. …

via Meltdown: Why ice ages don’t last forever – environment – 24 May 2010 – New Scientist.

Study: Many Sunscreens May Be Accelerating Cancer

Almost half of the 500 most popular sunscreen products may actually increase the speed at which malignant cells develop and spread skin cancer because they contain vitamin A or its derivatives, according to an evaluation of those products released today.

AOL News also has learned through documents and interviews that the Food and Drug Administration has known of the potential danger for as long as a decade without alerting the public, which the FDA denies.

The study was released with Memorial Day weekend approaching. Store shelves throughout the country are already crammed with tubes, jars, bottles and spray cans of sunscreen.

The white goop, creams and ointments might prevent sunburn. But don’t count on them to keep the ultraviolet light from destroying your skin cells and causing tumors and lesions, according to researchers at Environmental Working Group.

In their annual report to consumers on sunscreen, they say that only 39 of the 500 products they examined were considered safe and effective to use.

The report cites these problems with bogus sun protection factor (SPF) numbers:

* The use of the hormone-disrupting chemical oxybenzone, which penetrates the skin and enters the bloodstream.

* Overstated claims about performance.

* The lack of needed regulations and oversight by the Food and Drug Administration.

But the most alarming disclosure in this year’s report is the finding that vitamin A and its derivatives, retinol and retinyl palmitate, may speed up the cancer that sunscreen is used to prevent.

A dangerous additive

The industry includes vitamin A in its sunscreen formulations because it is an anti-oxidant that slows skin aging.

But the EWG researchers found the initial findings of an FDA study of vitamin A’s photocarcinogenic properties, meaning the possibility that it results in cancerous tumors when used on skin exposed to sunlight.

“In that yearlong study, tumors and lesions developed up to 21 percent faster in lab animals coated in a vitamin A-laced cream than animals treated with a vitamin-free cream,” the report said.  …

via Study: Many Sunscreens May Be Accelerating Cancer – AOL News.