Making Unique Observations in a Very Cluttered World

Thursday, 23 May 2013

Cockroaches evolve to avoid poison -- in just five years! -

Cockroaches evolve to avoid poison -- in just five years! - 

For decades, people have been getting rid of cockroaches by setting out bait mixed with poison. But in the late 1980s, in an apartment test kitchen in Florida, something went very wrong.

A killer product stopped working. Cockroach populations there kept rising. Mystified researchers tested and discarded theory after theory until they finally hit on the explanation: In a remarkably rapid display of evolution at work, many of the cockroaches had lost their sweet tooth, rejecting the corn syrup meant to attract them.

In as little as five years, the sugar-rejecting trait had become so widespread that the bait had been rendered useless.

"Cockroaches are highly adaptive, and they're doing pretty well in the arms race with us," said North Carolina State University entomologist Jules Silverman, discoverer of the glucose aversion in that Florida kitchen during a bait test.

The findings illustrate the evolutionary prowess that has helped make cockroaches so hard to stamp out that it is jokingly suggested they could survive nuclear war.

In a study published Thursday in the journal Science, Silverman and other researchers explain the workings of the genetic mutation that gave some roaches a competitive advantage that enabled them to survive and multiply.

The key is certain neurons that signal the brain about foods.

In normal cockroaches, glucose excites neurons that tell the brain "Sweet!" In the mutant insects, glucose activates neurons that say "Sweet!" and ones that say "Yuck!" The "Yuck!" neurons dampen the signal from the others, so the brain gets the message the taste is awful. This unusual nerve activity appeared in glucose-hating cockroaches collected from Puerto Rico as well as descendants of the Florida insects.

The research focused on the German cockroach, a small kind that can hitch a ride into your home in a grocery bag, not that big lunk known as the American cockroach. Such finicky eating habits have also been seen in these smaller roaches in Southern California, Cincinnati, Indiana, South Korea and Russia. Scientists are now looking to see if other kinds of cockroaches show aversion to glucose.

The new work is nifty science. But does it explain why you can't get rid of the little buggers in your kitchen?

Probably not, said Coby Schal, another study author at North Carolina State.

Tests show that the glucose-hating cockroaches are happy to eat most types of bait these days, suggesting that manufacturers have removed the glucose or masked it, he said. (Bait ingredients are a trade secret.) What's more, the researchers found glucose-hating cockroaches in only seven of 19 populations they sampled from various locations.

Frankly, if the bait you put out isn't working, it's probably because you're using it incorrectly, suggested Schal, who said he consults to the pesticide industry free of charge.

Still, he said, the new work has potential to help many consumers. By studying how cockroaches evolve to evade our poisons, scientists may find clues to designing bait that the pests cannot resist.

It's not clear when the Florida cockroaches first encountered bait with glucose or how quickly they ditched their taste for the sugar, he said. But he said it's reasonable to estimate that it took maybe only five years for that glucose aversion to spread to so many cockroaches that the bait was no longer effective. That's about 25 generations of German cockroaches, which can reproduce about one to three months after they're born, Schal said.

The glucose aversion may have arisen in an individual cockroach in response to bait. Or it may have already been present in just a few individuals when the arrival of the bait suddenly gave them an advantage for surviving and reproducing. Their offspring would inherit the trait and increasingly replace other cockroaches.

Michael Scharf, an entomologist at Purdue University who studies urban pests but wasn't involved in the new work, noted that since the 1950s, cockroaches have shown they can also evolve resistance to insecticides. He agreed the latest results should help scientists develop better products to control roaches.


911 Dispatcher Tells Woman About To Be Sexually Assaulted There Are No Cops To Help Her Due To Budget Cuts -

911 Dispatcher Tells Woman About To Be Sexually Assaulted There Are No Cops To Help Her Due To Budget Cuts - 

An Oregon woman was told by a 911 dispatcher that authorities wouldn’t be able be able to help her as her ex-boyfriend broke into her place because of budget cuts.

Oregon Public Radio reports that an unidentified woman called 911 during a weekend in August 2012 while Michael Bellah was breaking into her place. Her call was forwarded to Oregon State Police because of lay-offs at the Josephine County Sheriff’s Office only allows the department to be open Monday through Friday.

“Uh, I don’t have anybody to send out there,” the 911 dispatcher told the woman. “You know, obviously, if he comes inside the residence and assaults you, can you ask him to go away? Do you know if he’s intoxicated or anything?”

The woman told the dispatcher that Bellah previously attacked her and left her hospitalized a few weeks prior to the latest incident. The dispatcher stayed on the phone with the woman for more than 10 minutes before the sexual assault took place.

“Once again it’s unfortunate you guys don’t have any law enforcement out there,” the dispatcher said, according to Oregon Public Radio.

The woman responded: “Yeah, it doesn’t matter, if he gets in the house I’m done.”

Police say Bellah choked the woman and sexually assaulted her. He was arrested by Oregon State Police following the incident.

“There isn’t a day that goes by that we don’t have another victim,” Josephine County Sheriff Gil Gilberson told Oregon Public Radio. “If you don’t pay the bill, you don’t get the service.”

The sheriff’s department had to cut 23 deputies and the entire major crimes unit after it lost a multi-million dollar federal subsidy, according to Oregon Public Radio. There are now only six deputies left.

The sheriff’s department even put out a press release warning domestic violence victims to “consider relocating to an area with adequate law enforcement services.”

Bellah pleaded guilty to kidnapping, sex abuse and assault.


Study: Women 40 Percent More Likely To Develop Mental Illness Than Men -

Study: Women 40 Percent More Likely To Develop Mental Illness Than Men - 

There is a gender gap for mental illness, with females being up to 40 percent more likely to develop some type of mental health condition than their male counterparts.

A new study to be published by Oxford University Press finds that women are nearly 75 percent more likely than men to have suffered from depression, and approximately 60 percent more likely to report an anxiety disorder.

The U.K. study was led by Dr. Daniel Freeman, who said his latest research set to appear in the book, “The Stressed Sex: Uncovering the Truth about Men, Women and Mental Health,” sets out to answer a simple but crucial question: are rates of psychological disorder different between men and women?

“This important issue has been largely ignored in all the debates raging about gender differences,” Dr. Freeman stated on his website.

Dr. Freeman said that because the conditions most affecting women were more common than those affecting men, overall mental health conditions were more common in women than in men, by a factor of 20 percent to 40 percent.

However, the study also found that men are more likely to report substance abuse disorders – around two and a half times more frequently than women. Conditions such as ADHD (attention deficit hyperactivity disorder) and schizophrenia did not have statistically significant differences between adult males and females.

“There is a pattern within – women tend to suffer more from what we call ‘internal’ problems like depression or sleep problems,” Dr. Freeman told The Guardian. “They take out problems on themselves, as it were, where men have externalising problems, where they take things out on their environment, such as alcohol and anger problems.”

In the U.S., it appears that mental health diagnoses have spread across the gender gap, even for children. A recent study by the Centers for Disease Control and Prevention found that up to one in five American youngsters — about 7 million to 12 million, by one estimate — experience a mental health disorder each year.


Arctic bacteria discovered breeding at record –15 C - offer clues about possible life on Mars -

Arctic bacteria discovered breeding at record –15 C - offer clues about possible life on Mars - 

Bacteria that can live and multiply in High Arctic permafrost at temperatures well below the freezing point of water have been discovered by a Canadian-led team of researchers, offering clues about the types of organisms that might exist in similar extreme environments elsewhere in our solar system.

The OR1 strain of the microbe Planococcus halocryophilus is capable of reproducing at –15 C — a record among all known living organisms — and may possibly be able to multiply at temperatures even colder than that, says a study published Wednesday in the ISME Journal. The bacteria remain active at temperatures as low as –25 C.

"You look at permafrost, you think of this frozen dead world, but it's not," said Lyle Whyte, a McGill University microbiologist who co-led the study with post-doctoral researcher Nadia Mykytczuk.

Coming up: Nadia Mykytczuk talks to Quirks & Quarks Saturday, May 25 at noon on CBC Radio One
"The study that we show here indicates there are organisms that are … capable of surviving and reproducing in the conditions in which it came from, the permafrost."

The bacteria were among 200 or 300 strains collected in 2004 from a permafrost core drilled by NASA on Ellesmere Island, Nunavut, as part of a project to develop robotic drilling techniques for use on Mars. The permafrost has been frozen for 5,000 to 6,000 years and the environment has an average temperature of about –16 C.

NASA collaboration
Whyte's team was asked to help NASA ensure the samples were not contaminated. Once the drilling was done, NASA had no further use for them and handed them over to Whyte, whose research group specializes in hunting for bacteria that can survive in extremely cold environments.

"For me, this stuff was gold," Whyte told CBCNews.ca in an interview, noting that drilling permafrost is very difficult to do.

Researchers in his lab spent years screening the many microbes in the samples and learning how to grow them at very cold temperatures — a challenge because the researchers have to keep the liquid environment they live in from freezing.

Once they succeeded, they found that the bacteria doubled in population about every 40 days at –15 C in a medium that contained 18 per cent salt, partly to keep it liquid. For comparison, seawater contains about 3.5 per cent salt.

Whyte, who holds a Canada Research Chair in environmental microbiology, estimates that the microbes would probably reproduce 100 to 1,000 times more slowly in their natural environment.

In the permafrost itself, the bacteria live in little veins of brine, he added. These tiny channels of extremely salty water form when water freezes and in the process expels impurities such as salt.

Whyte's team analyzed the genes of the bacteria and discovered that many of their enzymes and other proteins are highly adapted to working at cold temperatures. In addition, they are genetically programmed to produce high concentrations of osmolytes — small molecules that help retain water inside the cell so it can survive in very salty environments without getting the water sucked out of it via osmosis. The osmolytes also act as an antifreeze.

Similar environments on Mars, Europa
The team is interested in studying bacteria like these in order to understand how microbes live at subzero temperatures, Whyte said, and to use that knowledge to hunt for microbial life on places like Mars, Jupiter's moon Europa or Saturn's moon Enceladus.

"On Mars, we know there are permafrost environments, and we're pretty sure now that there are very cold salty environments as well," Whyte said, "which make them ideal targets for looking for similar types of life."

Europa and Enceladus are also thought to have cold salty water below their icy surfaces.

Whyte and his team are currently hunting for bacteria like P. halocryophilus that can survive in very cold environments, but unlike P. halocryophilus, don't need to breathe oxygen or eat organic carbon.

Closer to home, scientists are interested in learning more about how bacteria in permafrost might affect the release of greenhouse gases as the Arctic climate warms and the permafrost melts, Whyte said. The bacteria are also a potential source of biotechnology, such as cold-active enzymes that could have applications in products such as laundry detergents.

The study was funded by the Natural Sciences and Engineering Research Council of Canada CREATE Canadian Astrobiology Training Program, the Canadian Space Agency, the Polar Continental Shelf Program, Canada Research Chairs Program, and the Canada Foundation for Innovation.

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