Stories tagged Life Science

Nov
17
2010

Longevity record holder Jeanne Calment in 1895: She was only 20 years old and would live for another 102 years.
Longevity record holder Jeanne Calment in 1895: She was only 20 years old and would live for another 102 years.Courtesy Wikipedia
You know, today is Buzz contributor Thor's birthday. I'm not sure how old he is, but I think we're pretty close in age. He may be a little younger than I am. Whatever. It doesn't matter. But if he's like me, he's not just celebrating his birthday, he's complaining about it. Complaining that he just keeps getting older and older. Yeah, yeah, I know. You’re thinking: “Well, isn’t getting older better than the alternative?” Okay, I suppose it is. And I think Thor would agree. But for some life forms, it’s way, way better.

You can see what I mean over at the NOVA website's interesting interactive that goes through a list of several oldest living creatures on Earth. You’ll see that we humans get the short end of the stick, mortality-wise. Our oldest, verified member lived to be 122 years old. She was a French woman named Jeanne Calment who attributed her long existence to eating lots of chocolate and olive oil. From our normal four-score average perspective, it’s not a bad record, but it doesn’t hold a candle to some of our fungal or botanical co-habitants. Some of those have lived for thousands of years. There’s even a genus of water-borne, microscopic creatures known as Hydra that, due to its regenerative capabilities, may have achieved immortality, although all the votes aren’t in on that feat yet.

My personal favorites, however, are the bacterial spores trapped in salt crystals that have been revived and estimated to be about 250 millions of years old! That means they were living back when some Triassic archosaurs were trying to kick-start the Age of Reptiles. They also add credence to the theory that life on Earth may have originated from bacteria-bearing meteor impacts from outer space.

Okay, so it looks like, in the general scheme of things, we humans aren’t that impressive in the long-life department. But it doesn’t bother me too much - and again I'm guessing Thor feels the same way - because with Jeanne Calment’s record of 122 years it could mean we haven’t even reached middle age yet. Happy birthday, Thor!

SOURCE
NOVA site

Nov
10
2010

This scanning electron micrograph depicts a number of Vibrio cholerae bacteria; Magnified 22371x.: Cholera can be simply and successfully treated by immediate replacement of the fluid and salts lost through diarrhea. Severe cases also require intravenous fluid replacement.
This scanning electron micrograph depicts a number of Vibrio cholerae bacteria; Magnified 22371x.: Cholera can be simply and successfully treated by immediate replacement of the fluid and salts lost through diarrhea. Severe cases also require intravenous fluid replacement.Courtesy CDC/ Janice Haney Carr
Picture yourself lying in a bed with a hole cut out under you to collect buckets full of unstoppable diarrhea. Now imagine your child lying there. Finally, pretend you are not one of the lucky ones lying on a cholera cot in a hospital, but are lined up outside a hospital in the street.
Cholera is an ugly disease.

The bacteria makes a toxin that shreds the intestinal lining, causing white flecks that look like rice to be passed in huge volumes of watery diarrhea. In hospitals, these “rice water stools” are collected and measured in buckets so body fluids can be replaced. Adults can lose up to 22 liters a day while battling this devastating infection. Without fluid and electrolyte replacement, most victims die from shock.

Lucky patients that recover often still carry the bacteria and can infect others. They can even re-infect themselves.

Cholera bacteria can survive outside the human body in water. They do especially well in dirty water. Unsanitary conditions are breeding grounds for Vibrio cholera.
I read this morning in the New York Times that cholera has spread from the Hatian countryside to the crowded, unsanitary camps of the earthquake survivors in Port-au-Prince. The camps don’t have clean toilets and are often flooded when it rains. Over a million people live in filth and poverty. According to the article, health officials predict that over 270,000 people could get sick with Cholera over the next few years.
People like you, and me, and our kids.

What can you do to help? Support aid organizations that are mobilizing to get clean water, water purification supplies, and medical supplies to Haiti. Once the supplies arrive though, it’s up to the Hatian government to make sure workers are able to get them to the people most in need. Let’s hope they do.

(This blog post was originally posted on the Kitchen Pantry Scientist blog.)

Nov
10
2010

Blood smear containing Yersinia pestis plague bacteria: Note the characteristic bipolar, "safety-pin"-like appearance of the Y. pestis organisms. People usually get plague from being bitten by a rodent flea that is carrying the plague bacterium, or by handling an infected animal.
Blood smear containing Yersinia pestis plague bacteria: Note the characteristic bipolar, "safety-pin"-like appearance of the Y. pestis organisms. People usually get plague from being bitten by a rodent flea that is carrying the plague bacterium, or by handling an infected animal.Courtesy CDC/ Dr. Jack Poland
In 1348, Pope Clement VI’s physician wrote the following as the “Black Death” hit Avignon: “It was so contagious, especially that accompanied by spitting of blood, that not only by staying together, but even by looking at one another people caught it…The father did not visit his son, nor the son the father. Charity was dead and hope was crushed.” (From Deadly Companions by Dorothy H. Crawford).

Scientists have long suspected that the bacterium Yersinia pestis,which causes bubonic plague, caused the Black Death that killed over 30% of Europe’s population in 1347 and continued to burn through Europe for the next three hundred years. Two teams of scientists reported this week that not only was Yersinia pestis definitely the microbe that caused the Black Death, but that bubonic plague has its roots in China, where it has lived in fleas in the wild rodent populations for thousands of years. Humans are an accidental host of this deadly bacterium, but in three major waves it decimated the populations of Europe, Asia and Africa, causing the most dramatic fall in population ever recorded.

Y. pestis is carried by fleas, who are made ravenous by the bacteria and jump from rodent (often rats) to rodent looking for warm blood and injecting thousands of bacteria with each bite. As rats die, the fleas sense the cooling blood and jump to new victims. If the victim is human, they will probably be infected with bubonic plague and, if untreated with antibiotics (which they didn’t have during the middle ages), stand a pretty good chance of dying. If the infection goes to the victim’s lungs and they infect someone else by coughing on them, that person is as good as dead.

Bubonic plague eventually died out in Europe, but not before infected rats stowed away on ships traveling to the United States in the 1890s, where they arrived in San Francisco and quickly infected the squirrel population. Over 50 kinds of rodents in the Western U.S., Canada and Mexico are potential hosts for Y. pestisis and the bacteria is still surviving in these populations, from California to Colorado. Fortunately, as long as the disease stays in wild rodents and away from urban rat populations, it probably won’t cause many cases of plague in the U.S.A. (there were only 15 in 2006.) We’re lucky to live in the age of antibiotics, which can treat most cases of plague today.

What should you do if you don’t want to catch the “Black Death?” Avoid wild rodents like the plague.

(This blog post was originally posted on the Kitchen Pantry Scientist blog.)

Nov
05
2010

Aiding and abetting science: Prison inmates have been enlisted to help forest ecologist Nalini Nadkarni in her research.
Aiding and abetting science: Prison inmates have been enlisted to help forest ecologist Nalini Nadkarni in her research.Courtesy Nalini Nadkarni
Since 2004, scientist Nalini Nadkarni has enlisted prisoners to aid in her scientific research.

Don’t worry, it’s not cruel and usual punishment. The inmates aren’t being used as guinea pigs to test new drugs or try out some new method of electroshock therapy. Instead, the incarcerated offenders are part of Nadkarni’s research team. Nadkarni holds a PhD in Forest Ecology and is on the faculty at Evergreen State College in Olympia, Washington. The National Science Foundation (NSF) has funded some of her inmate-aided research.

For one of Dr. Nadkarni'sDr. Nalini Nadkarni
Dr. Nalini NadkarniCourtesy Nalini Nadkarni
research projects, offenders at the Stafford Creek Corrections Center in Aberdeen, Washington, helped plant seeds of rare prairie plants then recorded data during the plants growth stages. The prisoners actually enjoyed helping out with the research. Not only did it give them a sense of doing something worthwhile, it connects them to something that’s sorely lacking in the old Graybar Hotel: nature.

For another project called Moss-in-Prisons (no Thor, your hero Randy has been picked up by the Tennessee Titans), Nadkarni recruited inmates at the Cedar Creek Corrections Center in Littlerock, Washington, to help discover improved ways of cultivating slow-growing mosses.

"I need help from people who have long periods of time available to observe and measure the growing mosses; access to extensive space to lay out flats of plants; and fresh minds to put forward innovative solutions," Nadkarni said.

If successful, the research could help replace ecologically important mosses that have been stripped from old-growth forests in the Pacific Northwest, a sometimes illegal tactic that seems to be a favorite among some horticulturists.

In many cases, helping with the research isn’t just a way for inmates to pass time behind the brick walls and barbed wire of their confinement. It’s also a way to inspire them. One former inmate, who had worked with Nadkarni, enrolled in a Ph.D. program in microbiology after his release from Cedar Creek, and went on to give a presentation of the research he had done there at the annual meeting of the Ecological Society of America.

Apparently, Dr. Nadkarni is on to something, and its importance is not lost on those still behind bars.

"It teaches me something," said one prisoner involved with Nadkarni’s prairie plant study. "It makes me work with people and it's just a new skill that I've learned."

Both science and prisoners benefit from this natural symbiosis taking place in such an unnatural setting. And other prisons have expressed interest in getting their inmates involved in Nadkarni’s research programs,

"Everyone can be a scientist,” Nadkarni says. “Everyone can relate to nature, everyone can contribute to the scientific enterprise, even those who are shut away from nature.”

SOURCES
NSF story and video
NSF press release

Nov
04
2010

You think you’re safe from the dangers of the wild just because you live in a city? This video will change your view. It was shot by a guy named Craig Kuberski, who lives within the city limits of St. Paul, MN. I know some of you were hoping you'd get to see a rogue cougar or bear mauling innocent urbanites or eating their pets, but that’s not the case here. It’s just a couple of bucks on the town and in a rut trying to catch some city girls' attention.

Rutting period is the mating season for many ruminants, (i.e. mammals like moose, caribou, bison, and deer). The rut is set-off by the shortening of daylight hours during autumn and in the case of white-tail deer (Odocoileus virginianus - which I’m pretty sure these are) can last for one to three months. During that time, male deer get all goofy and twitterpated, rubbing their antlers against trees, rolling in the dirt or mud, or battling each other – as seen in this video. Rutting season is the best time to hunt for them, and the easiest time to hit them with your car, although I don’t advise you do the latter.

As you may notice, Mr. Kubinski posted two buck fever videos on YouTube. I’ve only used the second here because it’s the better of the two, focus-wise, But if you’d also like to watch Part I, there you have it. KARE 11 also ran a story on it.

Nov
04
2010

Disease Detectives
Disease DetectivesCourtesy Disease Detectives
Earlier this year I got the chance to work as the crew of high school staff in the Kitty Andersen Youth Science Center (http://www.smm.org/kaysc/) at the museum to create a series of web-based videos about infectious diseases for the Disease Detectives exhibit. We worked from January through August learning video production skills, learning about different infectious disease topics, talking to experts and folks on the museum floor. We're just getting the videos online now, and all of our videos will be on the exhibit website soon (www.diseasedetectives.org) but I wanted to share them here as well.

For this video, titled "Got Beef? The Story Behind Antibiotics and Livestock" the crew to a slaughter house on in South St. Paul, the Minnesota Department of Health, U of M St. Paul (at 7AM to see the cows grazing), Mississippi Market Co-op, and did hours of research, prep, and post production.
Got Beef? The Story Behind Antibiotics and Livestock from Disease Detectives on Vimeo.

You can check out the video here.

Oct
15
2010
It's Friday, so it's time for a new Science Friday video. Science Friday
Science Friday
Courtesy Science Friday
Today,
"Reporting in the journal Science, Paul Kubes and colleagues filmed immune cells called neutrophils finding their way to a mouse's wounded liver. The researchers wanted to understand how neutrophils find injuries when bacteria aren't around to signal the damage."
Oct
05
2010

Normal human brain: Well, okay maybe Abby Normal is a better description. It is my brain after all. I had a recent MRI and was really glad to see I had something other than rocks in my head.
Normal human brain: Well, okay maybe Abby Normal is a better description. It is my brain after all. I had a recent MRI and was really glad to see I had something other than rocks in my head.Courtesy Mark Ryan
A new study appearing in the Journal of Palliative Medicine reports how several terminally ill patients all showed identical surges in their brain activity just before they died. At first the doctors at George Washington University Medical Faculty Associates who did the study thought the surge was being caused by interference from life-support machines or other electronic gear in the room.

“But then we started removing things, turning off cell phones and machines, and we saw it was still happening,” said lead author Lakhmir Chawla.

Speculation of what causes the neurological hyperactivity at the moment of death is that neurons in the brain, suddenly deprived of blood pressure and oxygen, shut down in rapid succession resulting in a final burst of neural activity - an electrical death rattle if you will. But the idea doesn’t seem to be a very new one. Kevin Nelson, a researcher studying near-death experiences at the University of Kentucky claims it’s well known that the brain experiences a sudden discharge of electrical energy when blood flow to it is cut off.

So, I’m not sure I see what the big surprise is here. If this is so well-known then why wouldn’t the doctors at George Washington University Medical Associates already know this?

But there’s another part of this that’s interesting. The surge may also be responsible for the "white light" reported by some patients who have had near-death episodes. The lore surrounding this phenomenon is about patients seeing an intense bright light when they're dying. But, according to Chawla, the majority of people involved in such incidents report having no such “white light” occurrence, but merely a vivid memory that may have been burned into their brain by the “final” electrical discharge.

And what about the so-called "out of body experience" patients sometimes report after slipping from the grasp of the Grim Reaper? Well, that, too, could come from the brain's electrical shutdown. A study that appeared in the journal Nature in 2006 reported patients sensing "shadow figures" laying nearby, or hovering above while certain areas of their brains were being stimulated with electrical currents. The charges interfered with the sensory information being received by the brain, and the hallucinations were just the brain's way of making senses of everythingl. The New York Times ran a story about it you can read here.

Bottom line, it looks like all those reported supernatural near-death experiences are just all in your head.

SOURCES
Discovery News story
International Association for Near-Death Studies website

Sep
22
2010

Newly discovered wood-eating catfish: held by Paulo Petry.
Newly discovered wood-eating catfish: held by Paulo Petry.Courtesy Paulo Petry via the Nature Conservancy
If catfish are your thing (and why wouldn't they be?) then you'll be happy to learn about a new species of wood-eating catfish that's been discovered in the confluence of the Purus and Curanja rivers in Peru. Local people (Nahua) have been eating the armored catfish for a while but until now the only specimens scientists have seen were dried carcasses. That changed recently when researchers led by freshwater scientist Paulo Petry finally caught some live ones. I'm happy to report as one would expect, it is one ugly creature. The fish (which ranges from 12 to 25 inches in length) has a mouthful of specialized spoon-shaped teeth perfect for stripping wood from trees that have fallen into its river habitat. Very kissable as you can see here. Even though it ingests the wood, it doesn't digest it. The nutrients contained in the wood are absorbed in the fish's gut and the wood itself is excreted as waste.

This new species has yet to be described and remains unnamed but is included in the genus Panaque, to which all wood-eating catfish belong. More info and an interview with researcher Paulo Petry can be found on the Nature Conservancy blog.

Sep
22
2010

Salmonella invades human cells: Color-enhanced scanning electron micrograph showing Salmonella typhimurium (red) invading cultured human cells.
Salmonella invades human cells: Color-enhanced scanning electron micrograph showing Salmonella typhimurium (red) invading cultured human cells.Courtesy Rocky Mountain Laboratories,NIAID,NIH
More than half a billion eggs were recalled after Salmonella sickened over 1600 people (according to the Center for Disease Control, or CDC in September.) That’s a lot of eggs, and a lot of sick people.

What is this nasty bacteria that makes us wonder whether we should let our kids eat raw chocolate chip cookie dough, even as we sneak several spoonfuls when they’re not looking?

Salmonella enterocolitis is one of the most common types of food poisoning and is caused by the bacteria Salmonella Enteriditis. You can get a Salmonella infection by swallowing food or water that is contaminated with the salmonella bacteria. Often, the culprit is surface contamination from raw chicken and raw or undercooked eggs. In most people, it causes diarrhea, fever and abdominal cramping, but young children and those with weakened immune systems are at greater risk of dehydration and more serious infections.

Why don’t they just wash the eggs better? Salmonella bacteria live in the intestinal tracts of animals and birds and can infect the ovaries of healthy-looking chickens. This allows bacteria to infect the eggs even before the shell is formed and voila- you have a pathogen that can’t be washed off of the egg because it’s inside. Salmonella bacteria are often found in the “white” of an egg, although they can migrate to the yolk as the raw egg sits in your refrigerator. Organic and free range chickens have less disease than factory-”farm” raised chickens, partly because of healthier diets and less crowding. Cooking eggs until the yolk is solid kills Salmonella bacteria.

How can you make your cookie dough and eat it too? Buy pasteurized eggs (you can find them at most grocery stores) that have been heat-treated to kill bacteria, but are still essentially raw for all cooking and baking purposes.

Also, remember to wash cutting boards you’ve cut meat on with soap and water before cutting anything else on them, or just have separate cutting boards for meat. Don’t forget to wash your hands after handling raw eggs! Pet food and reptiles can also harbor salmonella bacteria, so have your kids wash their hand after handling either!

Bacteria are everywhere. Some keep you healthy and some make you sick, but making good decisions in the kitchen can keep you and your family from being affected by food-born illness!

(This blog post was originally posted on the Kitchen Pantry Scientist blog.)