Stories tagged History and Nature of Science

Jul
19
2006

On Tuesday, the US Senate passed three bills regarding stem cell research.

Two were pretty uncontroversial: one encouraged stem-cell research using cells from sources other than embryos—adult bone marrow or hair follicles, or umbilical cord/placental blood. (The National Institutes of Health is already spending $571 million this fiscal year on this kind of stem cell research.) And one prohibited “fetal farming”—gestating fetuses for the purpose of providing tissue and other material for research.

The House of Representatives passed the bill about fetal farming, but voted down the bill promoting alternative stem cell sources. President Bush signed the ban on the commercial production of human fetal tissue into law today.

The third bill—which President Bush has just vetoed—would have expanded federal support of medical research using embryonic stem cells. Right now, researchers using federal funds can only study a handful of embryonic stem cell lines that existed before August 2001. The failed bill would have allowed federal funding for research on stem cells from thousands of unneeded embryos created in fertility clinics. (Couples with extra embryos resulting from fertility treatments would have had the option of donating them to research instead of having them destroyed by the clinic.) An override of the veto is unlikely.

What ARE stem cells?
Stem cells are simply cells that can develop into other types of cells. They can make copies of themselves indefinitely, and can become specialized for various body tissues. They are produced by embryos and also found in limited numbers in adults, but embryonic stem cells are pluripotent--they can become almost any kind of cell in the body--while adult stem cells are more limited. Scientists think they might be able to grow replacements for damaged tissues if they can coax stem cells to become the specific types of cells needed. Stem cells could someday provide treatments or cures for cancer, spinal cord injuries, burns, strokes, heart disease, Alzheimer’s and Parkinson’s, diabetes, and other ailments.

Mouse stem cells: (Courtesy NSF)
Mouse stem cells: (Courtesy NSF)

Why not use the pre-2001 stem cell lines?

In August 2001, the Bush administration and National Institutes of Health said that 60 stem cell lines had already been developed. Federal funds would be limited to research on those lines, and could not be used to create any more. But further investigation showed that less than 22 lines were actually available, and all of them had been maintained in culture dishes with blood products from rodents--scientists say the cells can’t ethically be used to treat people because of the danger of animal viruses and other contamination. Many of the lines aren’t aging well; if they don’t keep growing and dividing, they die, and some lines are accumulating mutations and other defects. Most research is limited to six of the stem cell lines. And they aren’t a very genetically diverse lot.

But the White House says,

"The use of mouse cells is standard scientific practice. ... As the Food and Drug Administration has indicated, the resulting stem cell lines can be carefully screened to ensure they are safe for use in any future clinical trials. Drug and biological products are routinely co-cultured with animal cells with no adverse consequences for the millions of people who have benefited from them."

Why not use private money?
Some labs have produced additional stem cell lines using private money, but researchers have to be scrupulous about segregating work on the newer cells from work done with federal money. The University of California, San Francisco, for example, is spending $5 million to set up a separate stem cell research lab where scientists can work without the federal restrictions. All the lab equipment they need already exists elsewhere on campus, but it can't be used for new stem cell work.

Some states see an opportunity in the federal restrictions. California announced that state money--$3 billion over 10 years--would be available for research into embryonic stem cells and therapeutic cloning. But the initiative is being fought in court. Connecticut has an 10-year, $100 million initiative. Illinois spent $10 million last year. New Jersey spent about $25 million in the last two years. And Maryland has approved a $15 million budget. But scientists in other countries are doing far more work with embryonic stem cells than scientists in the US. And losing out now means that the US could lose the eventual commercial applications developed through such research to the countries with looser regulations.

What's the issue with using embryonic stem cells?
Harvesting stem cells destroys a developing embryo. That's the crux of the whole issue. Those who oppose embryonic stem cell research say that the potential cures promised by stem cell research supporters offer false hope to some suffering Americans while encouraging the destruction of embryos to provide the cells. Members of the US Senate, debating earlier this week, expressed the gamut of opinions:

Senator Orrin Hatch (R-Utah) said,

"I do not question that an embryo is a living cell. But I do not believe that a frozen embryo in a fertility clinic freezer constitutes human life."

Senator Bill Frist (R-Tenn.), the Senate majority leader and a transplant surgeon, said,

"I believe that the progress of science and a pro-life position demand that Congress can send a message. I hope that we can redeem this loss of life in part by using these embryos to seed research that will save lives in the future."

Senator David Vitter (R-Louisiana) said,

"...I firmly believe that [neither] Congress, independent researchers nor any human being should be allowed, in effect, to play God by determining that one life is more valuable than another."

Senator Tom Coburn (R-Oklahoma), who is also a physician, said,

"The fact is, there is not one cure in this country today from embryonic stem cells."

Senator Tom Harkin (D-Iowa) said,

"So the choice is this ... throw [the embryos] away or use them to ease suffering and, hopefully, cure diseases."

Senator Sam Brownback (R-Kansas) said,

"We do not need to treat humans as raw material."

and

"It is immoral to destroy the youngest of human lives for research purposes. We don't need to do it."

Public opinion polls show that 70% of Americans support embryonic stem cell research. What do YOU think? Should the US government help fund it?

Jun
21
2006

Female Red Winged Blackbird: Red-Winged Blackbird (female) -- Hillman Marsh (near Point Pelee), Canada -- 2006 May.  Image courtesy Mdf.
Female Red Winged Blackbird: Red-Winged Blackbird (female) -- Hillman Marsh (near Point Pelee), Canada -- 2006 May. Image courtesy Mdf.
Q: What is a red-winged blackbird?

A: Red-winged blackbirds are a type of bird found in most of North and Central America. It is primarily a marsh bird and they are usually smaller than robins. The male’s red shoulder patches are what gives the bird its name. Although, by looking at these pictures, I think the female is the cooler looking bird. You can learn more about red winged blackbirds (and hear their songs/calls) here.Male Red Winged Blackbird: Red-winged Blackbird, male, Bluffer's Park (Toronto, Canada), 2005.  Image courtesy Mdf.
Male Red Winged Blackbird: Red-winged Blackbird, male, Bluffer's Park (Toronto, Canada), 2005. Image courtesy Mdf.

When searching for this answer I read up on red-winged blackbirds on Wikipedia. The images here are from that article. Interestingly, the photographer (Mdf) who took these pictures is on a mission to, “replace the barely adequate images of birds from the USFWS (and from other US Government agencies) with higher resolution, (hopefully) higher quality versions.” His images are impressive. This really has nothing to do with the question, but I thought it was cool, and worth mentioning.

Q: How do clouds form?

A: There are a lot of web resources about this, which I am going to defer to for this one – check out the “simple” answer at weatherquestions.com or read the article on clouds in Wikipedia.

Q: Why is blood red? Is it always red?

A: Iron atoms in our blood interact with oxygen to give our blood it’s red color. But not all blood is red! Horseshoe crabs have blue blood (due to the oxygen interacting with the copper in their blood), while most insects have clear blood as their “blood” is not involved in the transportation of oxygen.

Q: How long ago was this museum built?

A: The Science Museum’s current facility was opened in December 1999. The Science Museum was founded in 1907 as the St. Paul Academy of Arts and Letters, so we’re quickly approaching our 100th birthday!

Jun
12
2006

Here are some more random questions we've received from visitors to our website or our exhibits.

Q: Why is the Earth round? I thought it was flat.

A: Nope, the Earth is round. Not perfectly round, though. Planets like Earth are round due to gravity. Gravity pulls with equal strength in all directions, so gravity shapes the planet into a sphere. But, since the Earth rotates, the rotation adds centrifugal effects, which result in the Earth bulging slightly at the equator and flatten slightly at its poles.
Because of these centrifugal effects, the distance from the center of the earth to the surface of the earth is about 0.33% shorter at the poles compared to the equator.

Q: How does gravity work?

A: Gravity is one of the universal forces of nature, and is the tendency of objects with mass to accelerate toward each other. Newton's law of universal gravitation states that each particle of matter attracts every other particle with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

More simply, everything that has mass has gravity, and the larger the mass, the stronger the gravity. Earth has stronger gravity than the moon because the mass of the Earth is greater than the mass of the moon.

Q: What is zero gravity?

A: Lots of gravity related questions! Zero gravity, or weightlessness, is best termed microgravity. Astronauts floating in space are not actually weightless, or in zero gravity, because the Earth's gravity is holding them and everything in the spaceship they are in, in orbit. They are actually in a state of free-fall, much like jumping from an airplane except that you are moving so fast horizontally that, as you fall, you never touch the ground because the Earth curves away from you.

Think about it this way. Considering what we learned about gravity above, if you stood on a bathroom scale and then somehow opened some trap doors that dropped both you (still standing on the scale) and the scale out of a plane, both you and the scale would be pulled down equally by gravity. You would not push down on the scale and therefore, your weight would read zero.

Q: Why is the sky blue?

A: Sunlight is scattered across the Earth's atmosphere by a process called "diffused sky radiation". The sky is blue because much more short-wave radiation (blue light) is scattered across the sky than long-wave radiation (red light). Check out this website that explains more about this, and also why the sky appears red during sunsets.

Q: How come the Science Museum you only teach one side of the story? What I mean by this is that not everyone believes in evolution, and you only talk about that side of the story. Why don't you have exhibits on theories other than evolution such as intelligent design?

A: It's in our name. We're The Science Museum of Minnesota. We represent and teach science in our exhibits and programs. We're not saying that there are not other ideas or beliefs out there (intelligent design is not a scientific theory, rather a religious belief), and we respect others and their beliefs. However, as an organization that teaches science, we practice and encourage the teaching of evolution as fundamental to the teaching of sound science and critical thinking. If we were to compromise the scientific explanations of evolution or permitted unscientific alternative explanations into our exhibits or our programs, we would be misrepresenting the principles of science. Here is the Science Museum of Minnesota's official position on evolution.

Q: Do you like pie?

A: Yes. I especially like Key Lime pie.

Jun
05
2006

Gunther von Hagens’ BODY WORLDS exhibition provokes intrigue and questions about the scientific, cultural, and ethical aspects of anatomy and the preservation of human specimens, particularly in a public display.

Please join University of Minnesota experts for a FREE community forum series.

The Body on Display: Controversies and Conversations

Wednesday, June 28
Anatomy: Why We Dissect

Ken Roberts, Program in Human Anatomy Education, John Eyler, Program in the History of Medicine, and Dave Lee, Anatomy Bequest Program

Thursday, July 6
Boundaries and Bodies: Cultural and Religious Perspectives

Mary Faith Marshall, Center for Medical Humanities

Wednesday, July 12
Anatomy as Art, Art as Anatomy

Lyndel King, Weisman Art Museum, and John Eyler, Program in the History of Medicine

Wednesday, July 19
Stiff Morality: The Ethics of Using Bodies

Jeff Kahn, Center for Bioethics, will lead a panel discussion

Admission is free, but space is limited. Reservations for each session required.
To register, visit the University of Minnesota’s Academic Heath Center web page for the forums.

Location: Weisman Art Museum
333 East River Parkway, on the University of Minnesota campus.
7 - 8:30 p.m.
Light refreshments beginning at 6:30 p.m.
Parking is available for an hourly rate in the museum’s garage.
Questions? Call (612) 624-5100.

Sponsored by the Academic Health Center, Weisman Art Museum, Center for Bioethics, and the Center for Medical Humanities at the University of Minnesota.

May
12
2006

Today's Pioneer Press contains a letter to the editor from Ms. Sheila Steiner, of River Falls, Wisconsin. She writes:

"Would an anatomist in the U.S. have been allowed to skin a human body and fill it with plastic, pose it, and put it on display for a viewer fee simply because prior permission had been granted by the now deceased?

I cannot help but wonder how those who knew the living person think and feel about having their former loved one plasticized and on display.

It is reminiscent of an exhibit in Mexico where corpses were taken from graves and displayed to show how they had been preserved through minerals in the Earth.

It deeply troubles and saddens me to know that we have lost respect for the living as well as the dead. And we explain our unethical behavior as "an incredible learning opportunity".

Please skip the Body Worlds exhibit. Use your 20 dollars to feed the hungry or to buy a good anatomy book for a school."

Steiner's is a perfectly legitimate opinion, but what do you think? Whether you're here in the museum, and you've actually seen the exhibit, or you're visiting via the Internet, we want to know what you're thinking and feeling about the Body Worlds exhibit.

Did you find it gross? Beautiful? Disturbing? Fascinating? Moving? A little of each? Tell us about it.

Want to discuss the ethics of it? During the run of the exhibit, we're featuring four experts from our Advisory Committee (a Catholic theologian, a Hmong physician, a medical ethicist, and a body donation program director) to help answer questions and provide perspectives. Paul Wojda, a theology professor at St. Thomas University, is the first in this series. Ask him your questions!

May
03
2006

Why not consider becoming a bird-bander or net runner at Lee and Rose Warner Nature Center? Join us for a Bird-Banding Volunteer Open House! Learn about this special volunteer program at Warner in person and see if it's for you. Banders are responsible for setting up mist-nets, regularly checking them to carefully remove ensnared birds, taking nets down and assisting in the bird-banding process. Typically, a Warner “primary bander” delivers a 30-minute program on banding to school program groups while banding captured birds. Net runners assist with bird retrieval and data entry. A love of birds, the outside, and being around children is useful. No banding experience is necessary, but a willingness to learn and ability to hike through the woods is required.

  • Registration: Call 651-433-2427 to register. Registration is required.
  • Cost: No fee. Refreshments will be provided.
  • When: Saturday, May 13, 2006 from 9:00-10:30 a.m.
  • Where: Warner Nature Center (feel free to call for directions).
Apr
22
2006

Today was Earth Day. Did you celebrate?

Here are some Earth Day resources:

Want to know your ecological footprint? (The Frequently Asked Questions page at the end is particularly interesting.)

This is a kids' Earth Day site. You can play games, download a coloring book, crafts, or recipes, adopt a rainforest animal, and learn the history of Earth Day.

Visit the US Government's Earth Day portal. It lists environmental highlights, suggestions for how you can make a difference, and volunteer opportunities. It also has teacher resources.

The Yahoo! web portal has a list of 10 easy things you can do to slow climate change.

Mar
24
2006


A mirror in the sky: Courtesy gualtiero

Here in Minnesota the days are finally getting longer and we’re getting more daylight each day. Residents in the Austrian town of Rattenberg are also grateful for the return of spring’s longer days. You see, Rattenberg gets no sunlight at all from late fall to mid-winter. The town was founded some 700 years ago and was uniquely situated between the Inn River and the Rat Mountains for protection from bandits. However, the same mountains that protected the town from bandits also leave it in shadows from November to mid-February as the sun never rises far enough on the horizon to shine directly onto it.

People in Minnesota sometimes get a little discomforted during the shorter days, some even suffer from Seasonal Affective Disorder (SAD), which is a mood disorder associated with depression episodes related to seasonal variations of light. I can’t imagine what it would like to live in a shadow for over three months of the year – knowing that there is sun, but that it is blocked by a nearby mountain. Residents of Rattenberg have been leaving the town for sunnier locations and the town’s population is declining.

To help its residents get some light during the winter the town is working with Bartenbach Light Laboratory to install 15 heliostats (giant mirrors that track the movement of the sun) about a quarter of a mile outside the town – and beyond the reach of the mountain’s shadow. The heliostats will reflect the sunlight to a giant mirror covered tower in the city, which in turn will reflect the light to small mirrors on buildings throughout the town, which then transfers the light to the streets. The heliostats and mirrors will be installed this August at a cost of around $2 million. The hope is that tourists, who frequent the town in the summer to purchase blown glass artwork the town is famous for, will now visit year-round, and that residents will no longer look to leave for sunnier locations to live.

Mar
09
2006

Have you had your wisdom teeth pulled? I have. And they were impacted. Not on my list of all time favorite memories — in fact, having teeth pulled is one of my least favorite things to do.


Wisdom teeth: Earliest known impacted wisdom tooth. Digital radiograph (X-ray) of the mandible of Magdalenian Girl showing impaction of the right lower third molar (wisdom tooth). New high-quality radiographic imaging of the entire Magdalenian Girl skeleton, which is

Apparently, it was also not a favorite thing to do for the "Magdalenian Girl" (also known as the Cap Blanc skeleton), a nearly complete 13,000- to 15,000-year-old skeleton excavated in France in 1911and acquired by The Field Museum in 1926. To be fair, the pulling of wisdom teeth may not have been possible for her, but it turns out that her wisdom teeth are proving very valuable.

It had been previously believed that the Magdalenian Girl was under the age of 18 at the time of her death because her wisdom teeth had not grown in, which usually happens between the ages of 18 and 22 (I was 20). But after a new analysis of the skull, scientists now believe the Magdalenian Girl was actually between the ages of 25 and 35 when she died. This new theory has come about after looking at new digital X-rays (such as the one pictured) which show that the Magdalenian Girl's wisdom teeth were impacted.

So, why is that a big deal? Impacted wisdom teeth are thought to be the result of dietary changes that occurred in past human cultures. It is believed that impacted wisdom teeth were not common during the stone ages because the food that people ate at that time required them to chew more and chew more vigorously. This more intense chewing would have resulted in increased jawbone growth, which in turn creates more room for the wisdom teeth to grow in. When the diet changed to foods that required less forceful chewing the jawbone was not stimulated to grow as much, making less room for wisdom teeth when the time came for them to grow in. So, the fact that Magdalenian Girl has impacted wisdom teeth tells scientists that the diet of her time period would have already changed.

The skeleton of the Magdalenian Girl, the most complete Upper Paleolithic skeleton available for study in North America, is a part of the new permanent exhibition at the Field Museum called Evolving Planet. If you happen to see the exhibition, make sure you also check out the Kristi Curry Rogers' Rapetosaurus krausei also on display in the exhibition. Kristi is the Science Museum of Minnesota's Curator of Paleontology.

Feb
09
2006

James Kakalios, a current "Scientist on the Spot", will give a presentation about his book, The Physics of Superheroes, on Thursday, February 16 at 7:00pm at the Hamline Midway Branch Library. For more information, contact: The Friends of the Saint Paul Public Library at 651/222-3242 or visit www.thefriends.org. His appearance is part of pretty neat line up of authors.

Another series of presentations that sounds pretty interesting is called "Dying: A Guide for Beginners" and take place at the Merriam Park Branch Library a bunch of times between now and March 28.