Stories tagged Life Science

Jul
18
2006

A new type of vaccine: New H5N1 vaccine trial. photo credit; WikiMedia,
A new type of vaccine: New H5N1 vaccine trial. photo credit; WikiMedia,

Are we ready for an avian flu pandemic?

Current flu vaccines require live chicken eggs and six months of brewing time. This method may provide too little, too late. A new, quicker, type of vaccine production and delivery system has been approved for trial in August. A company called PowderMed has produced vaccine by cloning a gene from the current circulating bird flu strain and slotting it into an existing DNA backbone vaccine. This "plug and play" system would enable rapid adaptation of the vaccine to include relevant DNA if a new and more dangerous strain develops. It is then enclosed in tiny gold particles and delivered using an injector powered by concentrated helium gas, which pushes the particles into the skin.

“We are very excited by the potential for our flu vaccine technology to address the major healthcare challenge that influenza presents, in particular in the event of an avian flu or other pandemic outbreak. Our technology has significant advantages over current flu vaccine technology particularly in terms of the speed of response in the event of a pandemic. As soon as a new influenza strain becomes known, our “plug and play” system would enable us to rapidly insert the relevant DNA gene cassette into our standard DNA backbone. A PowderMed manufacturing facility will be capable of delivering the vaccine requirements of an entire country within 3 months. This is not possible for other technologies.”
Just 1.2kg of vaccine DNA would be sufficient to vaccinate the entire population of the US twice - an initial dose and a booster dose. PowderMed has carried out a detailed feasibility study with contract manufacturing partners, which concludes that it could establish a manufacturing capability with a surge capacity of 150 million influenza vaccine doses in a three-month period. Dr Dix points out that this is critical since, “No other vaccine technology offers this speed of response. In the event of a pandemic, most deaths and illness will occur in the first six months of an outbreak. We believe that our technology offers the best potential to save lives and minimise the economic impact of a flu pandemic.” Dr Clive Dix, CEO of PowderMed

Sources:
Reuters
PowderMed press release(pdf)

Jul
14
2006

A whopping one in eight babies in the US is now born prematurely. (Doctors consider a baby “premature” if he/she is born before 38 weeks gestation.) And the US Institute of Medicine, in a report released yesterday, says urgent steps are needed to turn the tide.

Hanging in there: Premature infants born today are far more likely to survive, and at earlier ages, than those born even a decade ago. But they're also more likely to experience a whole host of both acute and chronic health problems. (Photo by maria mono)
Hanging in there: Premature infants born today are far more likely to survive, and at earlier ages, than those born even a decade ago. But they're also more likely to experience a whole host of both acute and chronic health problems. (Photo by maria mono)

You may be wondering, “What’s the big deal?” I kind of shrugged it off, too. After all, both of my kids were born at 37 or 38 weeks, and experienced no problems. And we’ve all heard miracle stories of babies born as early as 22–25 weeks surviving.

Turns out that’s the magic word—surviving—along with thriving.

About 20% of babies born before 32 weeks gestation don’t survive their first year, and many premature infants experience life-long health problems, such as asthma or other lung disease, cerebral palsy, blindness, hearing loss, and retardation or learning disabilities. Even babies born only a week or two early have additional health risks and 30% higher medical costs compared to kids born at 40 weeks.

Trying to keep premature infants alive and thriving costs the US $26 billion a year. No one’s suggesting that we shouldn’t do everything possible for these little guys, of course, but is there any way to improve the situation?

What causes premature birth?

Ah, if only we knew.

Infertility treatments are one cause: moms who take fertility drugs or undergo in vitro fertilization (IVF)are more likely to become pregnant with twins, triplets, or even higher order multiples, and those babies are far more likely to be born early than singletons. (62% of twins and 97% of other multiples conceived this way were born prematurely.)

But they explain only a fraction of the nation’s premature births.

Certain infections can cause early labor. Other risk factors are poor diet, obesity, maternal stress, lack of pre-natal care, and smoking. Mothers under 16 or over 35 are more at risk, as are poor women, and black women. But differences in socio-economic status and behavior don’t completely explain the problem, either.

(Interestingly, the rate of premature infants born to black women (17.8%) has decreased slightly in the last decade while it’s increased for infants born to white women (11.5%). The authors of the study say this is because black women are less likely to undergo fertility treatments increasingly used by white women.)

Truthfully, doctors don’t know what causes most preterm births or how to prevent them. And they have only a few tools to predict which women will experience preterm labor.

So what should we do?

The US Institute of Medicine recommends three things:

  • Doctors who practice IVF should implant fewer embryos at a time. (The issue in the US is this: insurance usually doesn’t cover the procedure, which costs roughly $15,000 a try, so doctors try to improve the odds of a woman getting pregnant by implanting several embryos at a time. Which sometimes works too well. Many countries in Europe allow doctors to implant only a single embryo at a time, but they also pay for multiple IVF attempts. Those countries have discovered that, despite paying more up front to achieve a pregnancy, they’re saving money on the back end by treating fewer premature infants.)
  • More pregnant women should undergo first trimester ultrasound exams. (This is the only way to be certain of the fetus’ age. With more and more women being induced or undergoing C-sections, it’s possible that some babies are being born prematurely because their parents and doctors thought they were older than they really were.)
  • And the government should increase funding for research into the causes and prevention of premature birth.
Jul
11
2006

I was sitting on our front stoop tonight, talking to my mother on the phone, and a family of raccoons was out for a stroll. They came from somewhere on the Tilsner Carton Factory property, crossed at the corner, and made their way into a neighbor's front yard.

Right now is actually the peak time to see raccoon families in the city. Baby raccoons stay with their mothers until the fall, at least, and now they're old enough to leave their dens and accompany their mothers on nightly food foraging trips.

Raccoons: Courtesy SeattleYogi
Raccoons: Courtesy SeattleYogi

Raccoons are omnivores, eating everything from frogs to fish to insects to eggs, berries, vegetables, pet foods, and garbage. They're equally comfortable in wilderness or and dense urban areas. They're intelligent, resourceful, curious, and dextrous, and keeping them out can be a serious challenge.

This site has cool pictures of raccoons and their tracks.

Raccoons are fascinating to watch, but one note of caution: like many mammalian carnivores, they can be aggressive if cornered or threatened, and they can carry rabies. So be careful if you find one in your garage or on your back porch. Their wariness about humans is what keeps them and you safe, so don't feed them or otherwise encourage them to visit you. But enjoy watching from a distance. (I'm just glad that this troop wandered into Josh and Jenny's yard instead of ours!)

Our summer phenology feature--which talks about raccoons as well as other species--will be online soon.

Jun
29
2006

Whooping Cranes: Whooping cranes.  Photo courtesy Hedgeman.
Whooping Cranes: Whooping cranes. Photo courtesy Hedgeman.

On June 22, two whooping crane chicks hatched at the Necedah National Wildlife Refuge in Wisconsin. These are the first wild chicks that have hatched in the Midwest in over 100 years.

The two chicks are offspring of a pair of whooping cranes that are a part of the Whooping Crane Eastern Partnership (WCEP), a collaboration of non-profit organizations, individuals and government agencies whose goal is to bring a migratory flock of whooping cranes back to eastern North America. The hatching of these two chicks is a major milestone in this effort.

Whooping Crane Migration

Operation Migration teaches a migratory route to endangered birds. To do so, they raise young whooping cranes in isolation, which then fledge over their future breeding territory in Wisconsin. When the time comes to migrate, they follow an ultralight aircraft from the Necedah National Wildlife Refuge in Wisconsin to the Chassahowitzka National Wildlife Refuge in Florida. Once they have learned the migratory route they migrate on their own the following year.

Whooping Cranes Migrating: Because of Operation Migration whooping cranes can make the migratory flights south in the fall and north in the spring on their own.  Photo courtesy thelastminute.
Whooping Cranes Migrating: Because of Operation Migration whooping cranes can make the migratory flights south in the fall and north in the spring on their own. Photo courtesy thelastminute.
Reintroduction of an endangered species

Wild whooping cranes are an endangered species that before this project only existed in the wild in two flocks. One is a non-migratory flock in Florida and the other is a migratory flock that summers in Wood Buffalo National Park in Canada and winters at Aransas National Wildlife Refuge in Texas. The National Audubon Society's 2006 list of the top ten endangered birds in the United States lists the whooping crane third behind the ivory-billed woodpecker and California condor.

Due to the risk of both of the natural flocks being wiped out by a single event such as a hurricane, an additional, experimental, flock of whooping cranes was established in the fall 2001. 64 of the 76 birds released for this experimental migratory flock have survived to April, 2006.

And now we can add two more to that population count.

Jun
20
2006

Common Vampire Bat: Courtesy of Wikipedia
Common Vampire Bat: Courtesy of Wikipedia

The common vampire bat (Desmodus rotundus) has a diet that consists exclusively of blood. These predators, which are approximately the size of a human thumb, are able to consume 1.4 times their body weight in blood each night.

So how do they do that?

Vampire bats have been known to have a keen sense of smell as well as the unique ability to sense infrared radiation given off by warm-blooded animals.

It was recently determined that they have another extraordinary sense, the ability to detect their prey based on the sound of its breathing. They remember the sound of their victim's breath and then use that fact to relocate the exact same animal to prey on later.

Researchers at the Ludwig-Maximilians-Universität in Munich, Germany, taught 3 vampire bats to associate 10 second recordings of human breathing with specific food containers. The bats recognized the sounds and connected them to the correct dispenser every time. They beat out humans who took a similar test using computers with touch-screens. Humans could not identify any of the breathing sounds under stress, but the bats were able to every time.

The researchers discovered that bats have specialized brain cells that are stimulated only by the breathing sounds.

Sounds scary!

Don't worry, you should be safe here in Minnesota, but if you ever find yourself sleeping outside in the rainforests of South America, be careful!

Jun
07
2006


Prairie grasses: This experimental plot contains four species of prairie plants. The nearby plots, going clockwise, contain eight species, four species, and 16 species. (Photo courtesy David Tilman, University of Minnesota)

Ecosystems containing many different plant species are more productive and better able to deal with stresses such as climate extremes, pests, and disease. Those are the findings, published in last week’s issue of Nature, of University of Minnesota ecologist David Tilman and colleagues Peter Reich and Johannes Knops.

It sounds familiar, doesn’t it? The debate about whether or not diversity stabilizes ecosystems has been going on for 50 years! But Tilman’s experiment is the first to collect enough data, over enough time and in a controlled environment, to confirm the hypothesis.

Tilman, Reich, and Knops spent 12 years studying 168 9-meter-by-9-meter experimental plots at the Cedar Creek Long-Term Ecological Research (LTER) site near Cambridge, Minnesota. Each plot was randomly planted with 1-16 perennial grasses and other prairie plants. Over the 12 years of the study, temperatures and rainfall varied, but the plots with more species and more root mass did better than the others. (Why root mass? Roots store nutrients and provide a buffer against climate variations. And perennial prairie plants have far more root mass than annual plants, such as corn and other crops.)


Experimental plots: This aerial photo shows the individual nine-meter by nine-meter plots. (Photo courtesy David Tilman, University of Minnesota)

So what does it mean?

Two things. First, biodiversity does matter when it comes to healthy ecosystems. Second, biodiversity is decreasing worldwide as human populations increase and forests and prairies have been replaced with farm fields, buildings, and roads. Tilman thinks that increasing diversity may be the key to both restoring ecosystems and meeting the energy needs of people around the world.

In a National Science Foundation press release, Tilman said:

”Diverse prairie grasslands are 240 percent more productive than grasslands with a single prairie species. That’s a huge advantage. Biomass from diverse prairies can, for example, be used to make biofuels without the need for annual tilling, fertilizers, and pesticides, which require energy and pollute the environment. Because they are perennials, you can plant a prairie once and mow it for biomass every fall, essentially forever.”

Jun
03
2006


Old Fruit: Researchers in the Middle East have discovered that people 11,400 years ago were planting fig trees, the earliest known planted crops.
It’s that time of early summer to dig out the packets of seeds, dig in the dirt a little bit and get that garden ready.

And this week researchers have found new evidence for what may be the oldest cultivated crop known to be grown by man.

Digging in ruins near Jericho on the West Bank, researchers have found the remains of figs that they believe are the first intentionally planted crops by man. According to dating sciences applied by the researchers, the figs were grown about 11,400 years ago. That’s about 1,000 years earlier than the previously believed-to-be earliest crops of wheat, barley and chickpeas.

What the researchers found were nine small figs in the ruins of a building. They were charred, which preserved them in a condition that allowed them to be analyzed using dating methods. The date of the fire was able to be determined by carbon-dating the remains of the fire.

It’s a bit of a twisting road to figuring out how people of that era could plant the figs. The figs themselves were sterile, not allowing for them to produce seeds that could grow new fig trees. That led researchers to figure out that people were planting stems of tree shoots into the ground to create new fig trees. This process would make fig trees to become domesticated before other fruit-bearer such as grapes, olives or other fruit plants.

The findings of the researchers were published this week in the journal Science.

There was no evidence that earlier man used the newly farmed figs to make fig newton cookies.

Jun
01
2006

I've had some too-close encounters with wood ticks lately. (None were feasting, however. Thank goodness!) And not while hiking around in brushy places, either. Some of them were right out in the open.


Tick2: aka wood tick, or American dog tick. Yuck.

I wondered if this meant that Minnesota was experiencing a tick population boom? And if there was a corresponding increase in tick-borne disease?

So I asked around. David Neitzel, an epidemiologist with the Minnesota Department of Health's Acute Disease Investigation and Control Division, told me:

"This is the time of year that wood ticks are really abundant in Minnesota. They can be found in a wide variety of habitats from wooded areas to grassy areas, and sometimes very open areas (i.e., lawns). Wood ticks don't transmit disease in Minnesota, but deer ticks (also called blacklegged ticks) transmit Lyme disease and a couple other diseases. Deer ticks are only found in wooded or brushy areas.

Please check out our website and click on 'diseases and conditions' then 'Lyme disease' for more information."

Science Buzz also did a feature on ticks and tick-borne disease. We want to hear your gross tick stories!

Ick. Just thinking about it makes me feel all itchy, like one is crawling on me.