Science All Week

Super Shrimp Eyes

2009-10-27T10:13:00.000-07:00

My first experience with polarized light was when I borrowed my husband's sunglasses. The light bouncing off of the lake was suddenly gone and I could see the fish swimming up to his fishing bobber. It was all very exciting and turned what was a moderately fun passtime, watching my husband fish, into the more action packed experience of seeing when the fish were interested in the lure.

Polarized sunglasses work by eliminating all of the light coming through the lenses that is oriented in a particular way. If you look at your digital watch through them you sometimes can't see the display because the light coming from the watch is oriented the same way that light bouncing off of the surface of the lake is. There are lots of ways that light can be oriented. It can be oriented in a linear way, an eliptical way, or even circular. Or, it can be totally unpolarized, meaning that it is oriented in lots of different ways because it is coming from more than one place at a time.

DVD players have a mechanism in them that changes the polarization of light but it only works for a limited spectrum of colors. In studying this shrimp, scientists have found a better, simpler, more versatile way to do the same thing. It could change the way lots of devices are made in the future.

Links:

The abstract

An easy to understand article about it

How polarized sunglasses work

Word of the Day

Wave Plate: The doohickey in your DVD player that changes the polarization of the light going through it.

Swine Flu

2009-10-26T08:48:00.000-07:00

We all remember how things got blown out of proportion last year and how a lot of schools closed down that really didn't need to, so it's easy to blow off the dangers associated with swine flu and ignore the recent headlines. I thought Microbiology Monday would be a good time to look into those headlines and see what's going on.

It's early in the year for a peak in flu activity but the swine flu numbers are about the same as the peak activity for regular flu. The CDC says that swine flu is widespread in 46 states and that deaths are up. Eleven children died of flu related illnesses last week. Nine of those were definitely swine flu. So, since it's still early, authorities are a little worried about what might happen later on.

Still, most people don't get that sick. Most people are sick for about a week and then get better, even without any treatment. It's not really understood why some people get really sick. The Pan-America Health Organization has found that anti-viral drugs do improve the chances of surviving a severe case of H1N1. People most likely to get a severe case of this disease are pregnant women, children under two-years-old, people with asthma or other lung diseases, and kids with neurological disorders. Secondary bacterial infections can occur that make things worse and increase the chances of death.

The best ways to protect yourself and others? It's noting we haven't already heard. Wash your hands and cover your mouth when coughing or sneezing. The Health Protection Agency in the UK recommends using a tissue to cover your mouth and then throwing it away right away. They also say that you should use a regular cleaning product to clean hard surfaces and give door handles as an example.

Links:

UK's Health Protection Agency... Advice for the public

CDC Swine Flu Update

World Health Organizatio n

Clinical Features of H1N1

Word of the Day

Pandemic: a disease that covers a large area and a large proportion of the population.

Happy Birthday William

2009-10-25T14:24:00.000-07:00

(image from pongmuseum.com)

Today is the birthday of William Higinbotham, who not only had a very fun last name to say but also created one of the very first video-style games. His goal was to make a display for a science exhibit that was fun and interactive and he created a tennis style game that was controlled with a knob and button and viewed on an oscilloscope.

Links:

All about early electronic games

All about Mr. Higinbotham's Game

Word of The Day

Oscilloscope: An instrument used to visualize electronic voltage.

New Cancer Drug?

2009-10-24T01:00:00.000-07:00

Medicinal chemists think they might have found a new way to kill cancer cells.

The problem with cancer cells is that they don't die. Regular cells are programed to divide only so many times before they die but cancer cells just keep going and going. Two of the drugs used in chemotherapy are cisplatin and carboplatin. These molecules are combinations of platinum with other chemicals and they work by turning the cell death mechanism back on. Unfortunately, the platinum based chemicals are resisted by some kinds of cancer.

A group of scientists working at School of Chemistry at the University of Leeds have developed some new coumpounds with the metals Ruthenium and Osmium that seem to work very well against the kinds of cancer that the platinum based chemicals don't work for.

Links

The Abstract

The Science Daily Article: easier to understand than the abstract. I really like this website.

American Cancer Society's info page for cisplatin

How the platinum drugs were discovered. It's a neat story.

Word(s) of the Day

(These definitions are quoted word for word from Wikipedia, which I don't usually do... I didn't think I had anything to add and also, it being chemistry, I thought it was more likely to be correct.)

Ruthenium (pronounced /ruːˈθiːniəm/ roo-THEE-nee-əm) is a chemical element that has the symbol Ru and atomic number 44. A rare transition metal of the platinum group of the periodic table, ruthenium is found associated with platinum ores and used as a catalyst in some platinum alloys.

Osmium (pronounced /ˈɒzmiəm/, OZ-mee-əm) is a chemical element that has the symbol Os and atomic number 76. Osmium is a hard, brittle, blue-gray or blue-black transition metal in the platinum family, and is the densest natural element. The density of osmium is 22.61 g/cm³, slightly greater than that of iridium, the second densest element. Osmium is found in nature as an alloy, mostly in platinum ores. Osmium is also used in alloys, with platinum, iridium and other platinum group metals. Those alloys are employed in fountain pen tips, electrical contacts and in other applications where extreme durability and hardness are needed.

Arctic Ice

2009-10-23T01:00:00.000-07:00

(Image from This National Geographic Article... there's a cool video there too. I can't help but think my husband should have been an field scientist in the arctic.)

I'm writing this about two days before you'll read it and it's snowing here, so when I started thinking about environmental science, the arctic came to mind. I wondered how things are going up there. Well, it turns out about like I thought, things aren't going all that well for the arctic and it's ice.

How do we know? Two ways, really. First we have all the satellite images taken over time and they tell a story of the ice growing and shrinking every year. Some years it's more than others but the overall trend is that the ice is shrinking a lot more than it's growing. Second, people actually go there and drill holes in the ice and check its thickness. All the scientific predictions seem to point to ice free summers up there in the not too distant future. Predictions vary quite a bit and nobody knows exactly when this might happen but some say it could be as soon as twenty years from now... and that hasn't happened for more than five thousand years.

Not everybody is all that upset about the ice going away. Shipping companies look forward to an ice free north and cheaper routes from Asia to Europe. While it's still not routine, one shipping company has managed to make the journey, battling the ice that's still there along the way. Remember that northwest passage we learned about in early American History? Someday there will probably be one that's regularly used.

Links:

Want to know how the arctic ice is doing right now? This is the place.

Curious about ice all over the world? This is the place.

NY Times article about the shipping company that made the NE passage.

The shipping company's story at their own web site.

Word of the Day

Cryosphere: All of the ice (aside from in people's freezers) on the planet.

Chandrayaan

2009-10-22T01:00:00.000-07:00

(image from the Scientific American article about the launch)

A year ago today the first Indian moon mission was launched, and so I thought today might be a good day to talk about some of the results of that mission. The Chandrayaan's job was to go to the moon, orbit it, and take measurements of it using a wide variety of instruments. I've found a couple of interesting things that came out of that mission.

First, some NASA instruments included on the Chandrayaan found water at the poles. They also took some pretty nifty pictures of the earth, including some showing the shadow of the moon during an eclipse. Check out the links section to see pictures and get the full story.

Second, there seems to be some interesting stuff going on with hydrogen and the moon. SARA was one of the instruments included on the mission. It originated from the European Science Agency and measured atoms reflected from the surface. It turns out that hydrogen protons traveling from the sun hit the moon and it was expected that they would all be absorbed by the surface, but for some reason one in every five of them bounce off. This is important because of the way hydrogen atoms move in straight lines without being moved around by magnetic fields. This could give scientists a new way to take pictures of the surface of the moon.

Links:

All about the SARA findings from the ESA

NASA's Mineralogy mapper

Word of the Day

Proton: A hydrogen ion has a positive charge and is sometimes just called a proton. This is because it is just a proton, all by itself, but it is also the positively charged subatomic particle
found in the center of other kinds of atoms.

Immunization Fever

2009-10-21T01:00:00.000-07:00

(Image from the Mid America Immunization Coalition)

Almost thirteen years ago I took my baby girl to get her immunized and the nurse told me that if she got a fever I could give her some children's Tylenol. I don't remember if she got that fever or not but I've heard other moms complain about it. Why would something that's supposed to keep my baby healthy make her sick?

The answer lies with the way the immune system works and the way a vaccine works. When you get sick your immune system fights the illness and keeps a record of it so that the next time you are exposed to that illness it can fight it better, and maybe even keep you from getting sick at all. This record is really a recognition of the outside coating of the organism that made you sick. One way to keep people from getting dangerous viral diseases is to give them injections of the outside coating part of the disease causing microbe. The immune system can then recognize the intruder and make its record without the person having to be really ill.

So what about that fever? Does this mean there were some live organisms that made it into the injection? Not at all. Fever is caused by the immune response. The high temperatures are part of the body's mechanism for fighting off intruders. When you get an immunization your body doesn't know that the microbes are dead. All it knows is that it found some foreign stuff in your blood, so it starts the process of fighting the intruder off.

Knowing how uncomfortable the fever makes babies, and how scary that is for their families, some scientists in the Czech republic were wondering if it would be okay to just give all of the infants some Tylenol when they got their immunizations. It turns out that the Tylenol made the babies' immune systems not work quite so well. This means that nurses will probably keep giving the same advice and some babies will keep getting the fever and will then need to be given medicine for it. It's still a lot safer than not giving them their immunization.

Links:

A summary of the article from The Lancet

A more in depth description of how vaccines work

Word of The Day

Antigen: a chemical on the outside of cells and viruses that the body can recognize and use to determine if the cell or virus came from outside of the body.

Itsy Bitsy Black Hole?

2009-10-20T01:00:00.000-07:00

(image from NASA)

A couple of scientists in China made a little black hole in the lab and their entire laboratory immediately disappeared along with several top government officials who subsequently declined to comment; having been reduced to their molecular components and all... Okay not really.

A black hole is defined as an area having so much gravity that light can't escape it. These guys were looking at the problem from the light angle, ignoring the gravity thing, so their "miniature black hole," didn't pose the same danger that a regular black hole might pose. What's more, they didn't use visible light, they used microwaves, which are easier to work with because they have a longer wavelength.

Qiang Cheng and Tie Jun Cui were using meta material, which has been billed as being capable of making actual invisibility cloaks. Meta material is engineered on a scale so small that it can be made to behave in unusual ways where light is concerned. In this case they used layers of tiny circuit boards in concentric rings. When they aimed microwaves at the rings none came back out. Instead the microwaves were converted into heat... so rather than thinking of it as a black hole, you might think of it more like a fancy microwave oven.

That might seem a little underwhelming until you consider that they figure they can do the same with visible light. Which might, if I understand it correctly, mean that you could turn off the light in a room for real, even during the day. Or maybe there would be solar applications for heating your home or creating more electricity than we can right now?

Links:

Why meta-material doesn't really make a very good invisibility cloak, yet.

The Abstract : arXiv:0910.2159v1 [physics.optics]

An easy to understand article all about it.

All about black holes, including what would happen if you fell into one.

Word(s) of the Day

Visible light: The stuff we can see... its wavelength measures between 400 and 700 nm more or less. We see the different wavelengths as different colors. Red, Orange, Yellow, Green, Blue, and Violet (which I learned as ROY G. BIV, which is what I'll name my third son). They are arranged from longest wavelength (red) to shortest (violet). Somehow light acts like a wave sometimes and a particle (called a photon) other times.

Hot Blooded

2009-10-19T01:00:00.000-07:00

(image from this article about a new way of fighting fungal infections)

When I get sick I usually ask myself if I think it's a bacteria or a virus making me ill. Most of the time it really doesn't matter. I'll end up feeling rotten for a while and then I'll get better. If I needed a doctor it's more important because I know antibiotics won't help with a viral infection.
However, I almost never ask myself if I'm sick because a fungus. That's because people don't get that many different kinds of fungal diseases. The ones they do get happen most often because of some kind of compromise of the immune system.

There's a scientist who thinks he has an explanation for this. Arturo Casadevall, M.D., Ph.D. says that it's the high body temperatures of mammals that keep fungus from growing. Other kinds of organisms like frogs, lizards, and plants, all get more fungal diseases than mammals do. He even hypothesizes that the dinosaur extinction had something to do with fungus.

Links

Word of the Day

Opportunistic: This refers to an organism that doesn't normally make you sick but will if it has the opportunity. This is used a lot for the kinds of illnesses that cancer patients might get during chemotherapy or AIDS patients might get. Just because it's opportunistic doesn't mean it won't kill you. Lots of people die of these kinds of infections.

The Martian Chronicles

2009-10-18T01:00:00.000-07:00

(image from Wikepedia's article about The Great Moon Hoax)
(I know the moon isn't Mars, but it's such a cool picture... and gee, if the public
was so easily convinced that there was life on the moon...?)

When I was in college I took an English class that required I read an excerpt from The Martian Chronicles by Ray Bradbury, which of course I had already read; Ray Bradbury being one of my childhood's beloved heroes. So when, in class discussion, a middle-aged student took issue with the story it made me mad. He told me that giving Mars a breathable atmosphere and actual martians was unforgivable and that the story was, "tripe". I tried to explain to him that we haven't know all that long what Mars is really like, but he would have none of it and I left that class so boiling mad that it still makes me angry to think about.

Now, in retrospect, it doesn't matter to me quite so much if Ray got his science just right or not. It's still a great read, written as nobody but Mr. Bradbury could have written it. Still, who was right in that argument? When did we know that Mars doesn't have a breathable atmosphere?

It seems like people have been speculating about life on Mars since telescopes were invented.

In the 1600's the light and dark spots were observed on the surface of the planet, along with white spots at the poles... it was assumed that the color variation was land and water and the white spots were polar ice caps. The day was calculated to be about the same length as ours. We have life... a planet like ours probably does too? It was the obvious assumption to make.

In the 1800 an Italian astronomer notices some lines on the surface and the Italian word for groove sounds an awful lot like the English word canal. The popular myth that these were canals built by Martians sprang up and proved to be persistent.

In 1907 a guy named Alfred Russel Wallace measured light coming from the surface of the planet and used it to determine that the temperature was negative 35 degrees F... way to cold for liquid water. (A bummer for my argument, because Bradbury's story had liquid water on the surface.)

Still, the book was published in 1950 and the atmosphere wasn't discovered to be made up of mostly CO2 till 1952, and the canal theory wasn't totally debunked until we got a probe close to the planet in 1964.

So, who was right in that long ago argument? I guess the other guy wins, sort of, but fiction, even science fiction, isn't measured entirely by its scientific veracity.

Links

Nasa's chronology of Mars Exploration

An Observational History of Mars: Going back to before it was even called Mars.

The abstract of a scientific paper that mentions blue clearing

Word(s) of the Day

Blue Clearing: also violet clearing. If you use a blue or violet lens to look at the surface of Mars, usually you don't see much, but during one of these blue clearing events certain details become very visible. It seems to have something to do with ice clouds and the refraction of light.

Barnacle Glue

2009-10-17T13:33:00.000-07:00

(image from thinkquest.org)

You've probably heard of barnacles but if you live in the middle of a large land mass like I do, you probably haven't thought much about them. They are small shelled creatures that stick themselves onto boats, rocks, and whales. They feed by sticking out filamentous "fingers" and filtering stuff from seawater.

A couple of scientists were wondering how barnacles glue can possible work underwater. You know, regular glue would not work because it wouldn't be able to set up. So they asked themselves what kind of stuff is already well understood to set up like that under water. The answer turns out to be blood and as it turns out, barnacles use a chemical process very similar to blood clotting in order to get their glue to work under water.

Blood clots when the platelets are changed chemically by specific proteins in the blood that are activated when you cut yourself. The scientists found these same kinds of proteins in the barnacle glue and when they added a chemical to inactivate the protein, the glue wouldn't work. Knowing this, they hope they can figure out how to keep the barnacles off of boats and save all kinds of money in the shipping industry.

Links

Here's a link to the full story on Science Daily

How blood clots

Word of the day

Trypsin: A protease... which means it's an enzyme that breaks down proteins.

Human Egg Candling?

2009-01-28T13:37:00.000-08:00

A while back on my personal blog I lamented our lack of ability to look at the chromosomes of an egg before it was fertilized. I spun an elaborate fantasy about a noninvasive human egg candling procedure that would tell if a particular egg might have some kind of chromosomal aberration (like Down's Syndrome).

Well, my fantasy remains pretty outlandish, but it turns out that there is a way to look at the genetic make-up of the egg before it is fertilized. I just wanted to make sure it had the proper number and right kinds of chromosomes but it can also be used to look into more specific things. The main reason it is used is to make sure that the egg is viable before implantation. This can cut back on the number of embryos they have to implant after in vitro fertilization in the hopes of having a healthy baby and hopefully, reduce the number of women who go from not having any baby at all to having four all at once.

The way it is done is to take the polar body out of the egg and do genetic testing on it. You might remember that in the process of reducing the number of chromosomes to half that of a regular cell, the egg produces these little things called polar bodies. Normally they disintegrate after the egg is fertilized but they contain the mirror half of the chromosomes that are in the egg. If there are any chromosomal abnormalities, you'd be able to tell from the polar body.

Of course, not everybody can afford IVF in the first place, but for those that can this might be a way to ensure that a woman my age (36) has a healthy baby. Most of us will probably just have to muddle along with nature and hope for the best... at least for now.

Links:

An abstract from a study about a possible function of polar bodies.

All about meiosis: scroll all the way down to see oogenesis.

Word Of The Day

gemetogenesis: The making of gametes. Gametes are the sex cells, or eggs and sperm. Sometimes you hear this referred to as spermatogenesis or oogenesis, meaning egg or sperm production. They are not produced in exactly the same way, which makes sense if you think about it. Eggs are large and have lots of cytoplasm. For the first divisions after fertilization there is no time for growth, so you end up with lots of cells the same size as the original egg. Sperm are little and have flagella so they can swim and find the egg. They don't contribute much (just the chromosomes they carry) to the size of the fertilized egg.

Slime and Cytoplasm

2009-01-26T01:00:00.000-08:00

(Image from this award winning young scientist's web page.)

The first time I saw real live amoeba in my undergraduate biology lab class I was so excited that I went home and told my family... who reacted with blank stares and shrugs, but really... cells that move around by what looks like a magical oozing motion are cool.

How do they do that? It seems that they have the same kinds of (or similar) proteins that our muscle cells have. These protein filaments can contract and make the cytoplasm move. It looks a lot more complicated than that to me, but that has always been the draw of these "wee beasties"... they act in what seem to be very complex ways.

You can see the same kind of thing happen without a microscope if you look at a plasmodial slime mold. Plasmodial slime molds are also protists, like the amoeba, but they fuse together and make what is essentially a really big cell that has a lot of nuclei in it. You can watch these things flow around without a microscope... and I still find it so exciting to watch that I wanted to share it with you.

In this You Tube Video you can see a slime mold start out in one lump and spread out to cover nearby objects... flowing in a complex-looking, fascinating, and slightly disgusting way.

Links:

Actin and Myosin in Nonmuscle Cells (from an online cell biology text)

You and 30 of your closest friends could culture your own slime mold for less than $1.00 each.

An Abstract from a paper about the toxicity of ethanol and some other chemicals on Plasmodial Slime Molds.

Word of The Day

Cytoplasm: The jelly-like contents of a cell.

Measurement

2009-01-25T01:00:00.000-08:00

Since science is really only concerned with what is measurable, measurements of various kinds are very important and pop up all over the place in almost any study of anything, but the numbers are only as good as the equipment and the people using the equipment. If you need centimeters and all you have are rulers with inches on them, you're in trouble. Or you could have the fanciest gas chromatograph on the market but only somebody like me to use it. It wouldn't do you any good.

If you've ever needed a really straight line, you have experience with this. The saying goes "Measure twice. Cut once." If you want a straight line you probably need more than two measurements. You start at the edge of your material and go... say ten inches (Why are you using inches instead of centimeters, anyway?). You make four or so marks along the length at ten inches and then try to connect them, but they aren't really all lined up. Some are a little farther out than others and you end up making a "best fit" line, which, if you are really lucky, looks straight.

What you are lacking is precision. Your lines are all pretty close to ten inches so your accuracy isn't bad, but sometimes you marked toward at the far end of the little black measuring tick and sometimes at the close end, also the ruler might have been at a slight angle sometimes, making slight variations in the measurements. Precision is the ability to come up with the same answer over and over again when measuring the same thing over and over, and it has a lot to do with both the equipment and the training of the person using it.

Accuracy is important too. Just because you came up with ten inches on the dot, every time, doesn't mean you have ten inches. Your ruler could be wrong or you could be looking at it and seeing the number ten where it should be twelve because the six-year-old took a pen to your ruler.

Precision sounds wonderful. It's a word that makes me think of professionalism, but precision without accuracy can be disastrous. Just think of the surgeon that could make a cut within a millimeter of where he intended, but took out the wrong organ. A little more accuracy and a little less precision might make the patient a little more alive.

Links:

If you ever need to collect measurements for the EPA... here are the methods.

The National Institute of Standards and Technology's Center for Nanoscale Science and Technology.

Here's how Australia measures things.

Word of The Day:

Bias: There are several ways this word is used in statistics (and we are talking about some very simple statistics here) but in measuring things, your group of measurements would be biased if they were wrong in some way that caused them not to fall into a "normal" bell curve... for instance, if they were precise but inaccurate because of that pen mark on the ruler's number two that made the 12 look like 10.

Making Hydrogen

2009-01-24T01:00:00.000-08:00

(the BMW hydrogen 7)

A group of scientists have figured out a seemingly easy way of getting hydrogen from water. They are using special clusters of aluminum atoms that are arranged in a way that allows them to act as catalysts.

Catalysts are very common in biology, so I know something about them. You do too, even if you don't realize it. Think about what happens when you pour hydrogen peroxide on a cut. It bubbles. Right? Why does it bubble?

Hydrogen peroxide has two hydrogen and two oxygen atoms in it (H2O2) and you have a catalyst called catalase in your body that helps free some of the oxygen, turning the peroxide into water and oxygen. A catalyst greatly decreases the energy and time required for a reaction to take place. In this case it's very dramatic. That hydrogen peroxide might turn into water and oxygen on its own... if left alone for a few decades... but add a little catalase and it happens in seconds. In your body catalysts are mostly proteins that "hold" onto the chemicals and apply pressure in just the way that encourages the chemicals to react in a specific way.

In the case of the aluminum (which is not a protein, but you knew that) it needs to be arranged in a cluster of atoms so that one of them has a tendency to accept electrons and another to donate electrons. This lets the water bind to the cluster and frees some hydrogen. Without the aluminum the reaction requires the addition of energy (heat or electricity) but with the aluminum clusters, the reaction can happen at room temperature. Now, if they can just figure out how to unbind the remaining oxygen and the extra hydrogen atom from the aluminum, they will be able to reuse the aluminum clusters over and over again.

Links:

Read all about it here.

Some facts about hydrogen as a fuel, from Stanford.

Phrase of The Day

Lewis Acid: A compound that can accept a pair of electrons. A Lewis Base can donate a pair of electrons. This is a slightly different than the definition of an acid as a chemical that has a pH less than 7.

Winter Fish Kill

2009-01-23T01:00:00.000-08:00

(There were plenty of fish in this lake... they just didn't want to be caught.)

The only time I generally fish is on the summer backpacking trip I take with my husband every year. We go to remote places so that we won't have much company, but it's incredibly frustrating to spend two days backpacking up to some remote mountain lake only to find that there aren't any fish. We've had this happen even when oldtimers have assured us that there is indeed a fish population in a particular lake.

The first time this happened on one of our trips my husband just shrugged his shoulders and said, "I guess it was winter killed". I pictured it being so cold up there that the lake froze solid, killing the fish... not too hard to believe when you are up at dawn in July, in the mountains, wearing three layers, a stocking cap and gloves, and still a little too cold for comfort. Even so, it isn't likely that a fairly deep lake would freeze solid. So what kills fish during the winter?

When it gets cold the water on top of the lake freezes. This is handy, Ice floating like that, or it might really be likely to freeze solid. However, the ice on top of the lake restricts the ability of the lake to absorb oxygen. This isn't so bad because the fish's metabolism slows and they don't use as much oxygen as in the summer. As long as light can filter through the ice there will be some oxygen produced by the plants, but if it snows a lot then the snow will block the light. Eventually, if it doesn't melt off soon enough, the dissolved oxygen levels become so low that fish will start to die.

Unfortunately, it seems that trout (our fish of choice) are particularly sensitive to this. The population will eventually bounce back as long as there is a stream or something to connect the lake with other fish populations.

... and we can always spend the time taking lots of pretty pictures.

Links:

EPA's information about mercury in fish.

National Fish and Wildlife Foundation

The Nature Conservancy's program to map freshwater biodiversity.

Word Of The Day:

Biodiversity: The number of different kinds of living things in a given area.

ESO's VLT

2009-01-22T01:00:00.000-08:00

(The center of a galaxy as seen by the VLT.)

Spend just a little time wandering around in the world of science and you'll run into a lot of esoteric acronyms that stand for very long and incomprehensible words. That's one reason I was intrigued by the VLT.

ESO is the European Southern Observatory, and VLT stands for Very Large telescope. There's an acronym I can live with.

The VLT is really four separate telescopes with mirrors 8.2 meters (26 feet and almost 11 inches) across. Each of these can be used alone, and generally they are used that way a lot, but when used together in groups (along with four smaller, movable Auxiliary Telescopes) they can greatly increase the resolution of an image. When they are used this way they are called an Interferometer.

Links:

A Really Excellent You Tube Video

An Explanation of Interferometry

Word of The Day

Resolution: The ability to distinguish two separate points as to distinct points rather than one big blur. The ESO website says that the VLT could see a car's headlights as two points if the car were on the moon.

Dementia

2009-01-21T01:30:00.000-08:00

Dementia isn't really a disease, it's a set of symptoms that can be caused by lots of different things. Can't remember where you put your keys? Well, if everything else seems to be working okay then you probably don't have dementia. Dementia is when you have two or more problems with the way your brain works and the list of symptoms is quite extensive. A person with dementia might have hallucinations, language problems, motor skill problems, or emotional and personality problems to name just a few.

Alzheimer's disease is the disease that comes into my mind when I hear the word dementia but vascular problems and stroke can cause it also, and there are several other diseases and disorders that can cause it. The scary thing about dementia is that it can't usually be cured and it gets worse over time.

What I want to know is, what can I do to prevent it from happening to me. There are some computer games and mind bending puzzles and things on the market for that and I was wondering if they were helpful or not. Here is what I've learned about Dementia prevention.

1. Since stroke and vascular problems cause some kinds of dementia, the kinds of things that prevent those problems are helpful. Quitting smoking, exercising, stress reduction, and eating healthier are good ideas.

2. For the above reasons, it makes sense that statin drugs would be a good idea for those at risk. This study seems to support that idea.

3. Ginkgo doesn't seem to help, according to this study.

4 While no one particular mind game seems to have been studied, it does seem that using your brain regularly reduces your risk for dementia.

Links:

Leisure activities and the risk of Dementia in the elderly.

The National Institute of Neurological Disorders and Stroke

A List of Symptoms

Word of The Day

Aphasia: A loss of language ability. This is usually caused by damage to the brain and can occur in some kinds of dementia. It may only be the loss of some words or it could be an inability to use them properly.

Cryobiology

2009-01-20T01:00:00.000-08:00

My dad had a buddy when I was growing up that swore up and down that if you took a live duck and put it in the freezer and froze it solid, you could then thaw it out and it would still be alive. I never tried it, so I can't say for sure if it would work or not, but I doubt it. Some animals can take very cold temperatures but the guy insisted that the duck could be frozen rock solid.

Then there are those companies that say they will freeze you so that some day science can figure out how to thaw you out and cure your ills and then bring you back to life? I wouldn't bother. Science has to figure out a safe way to do the freezing part before it's likely to work. The problem isn't in the thawing out, it's in the freezing.

When you take a few cells and start to freeze them, two different problems come up. First, if you are freezing them slowly, ice crystals form outside the cells. Ice is frozen water (I hope you knew that already) and so when it becomes ice there is now less water outside the cells. Water, in liquid form, tends to move from where there is more of it to where there is less of it. That's the process of osmosis and since there is suddenly less water outside the cells than there was, now the water moves out of the cells and dehydrates them, damaging them.

The second problem is caused when you freeze them quickly, like dunking them suddenly into a bath of liquid nitrogen. There is plenty of water inside the cells and it becomes ice crystals. Ice expands when it freezes (An oddity of water. Not all liquids are like that.) and the crystals cause severe damage to the cells.

So, if you want to freeze some cells you need a few things. You need to figure out the optimum rate of cooling and you probably need some mixture of solutes outside the cells that isn't toxic and can help keep the osmotic balance where you want it. These problems are solvable for thin layers of tissues where the cells are mostly similar or for individual cells of the same kind (like sperm) but large organs with lots of different kinds of tissues and cells in them pose greater problems that haven't yet been solved. You can't bathe all of the cells in the optimum solution (which might be different for different parts of the organ) and you can't freeze each of those tissues at the optimum rate.

True, we might solve the problem some day, but till then you might prefer to spend your money on things you can enjoy while you are alive, or you could donate it to you grandchildren's college fund. On the off chance that you don't have any grandchildren, I have paypal.

Links:

A simple and easy to understand description with diagrams.

The Society for Cryobiology

The abstract of a scientific paper about a method for figuring out if frozen bacteria are still viable.

Word (or phrase) of The Day

Osmotic Balance: This is defined differently for different situations but basically it always means that the water is staying where you (or the living system) want(s) it. In freshwater fish there is a higher water concentration outside the fish than in it. The fish has to keep too much water from invading its tissues and so pumps it out to maintain it's osmotic balance. In saltwater fish the situation might be the other way around. Remember, osmosis is all about water.

Hiatus

2009-01-15T13:45:00.000-08:00

Sorry about the unexpected hiatus. Regular posts will resume this coming Tuesday with a post about cryobiology.

Salmonella

2009-01-11T18:56:00.000-08:00

(Image from this UW Madisonpage)

This last summer we had a local outbreak of salmonellosis, which is what they call the illness caused by salmonella. Local officials traced it to our water supply but not before a lot of people got sick. My family didn't ever get sick, and nobody died, but the whole town was without water for a while.

Salmonella is a rod shapped bacteria that lives in the intestines of birds and animals and sometimes ends up in food (or water, in our case). Everybody is at risk from salmonellosis, but older people, very young people, or people who have weak immune systems, are at increased risk.

People who get the disease get a fever and diareah, and they might have headaches and nasea. It can be life threatening to those who are at increased risk for the diesease.

It gets into our food from undercooked meat and poultry, and occasionally from eggs. At one time only eggs that were contaminated with feces seemed to transmit the diease but now perfectly fine looking eggs can get salmonella in them before they develop a shell and leave the chicken. All eggs that you eat should be cooked or pasturized first. You can't pasturize eggs at home, at least I haven't seen anything anywhere to indicate this is possible or safe, but you can buy pasturized eggs in the carton in some parts of the country. Otherwise, you should "coddle" your eggs before making hollandaise sauce with them. I have a link to dirrections for this below.

Links:

Egg coddling... the microwave method at the bottom of the page looks easy.

USDA fact sheet about salmonella.

A stuffed giant sallmonella bacterium. Just what you always wanted.

Word of The Day

Bacilli: The plural form of bacillus, which means rod-shaped. Salmonella are bacilli.

Statistics

2009-01-11T01:00:00.000-08:00

Let me tell you a story about my graduate thesis. It was entitled The Partitioning of Benzo(a)Pyrene in the Pregnant Laboratory Mouse. What I was working on was how this chemical and it's metabolites move through the placenta and so I took tissue samples from the mother, fetus, and placenta of lots of mice and then compared the concentration of this chemical in all of the tissues. It was not terribly important research and was not published anywhere.

When I was writing up my results I went back to my Biostatistical Research Analysis class notes and figured out which mathematical test I needed to use to find out if there was a significant difference between the groups of samples. I found that there was and took the results to my mentor, who looked at them and told me I had it backwards.

A few weeks later I presented my research to the department and the statistician stood up afterward to tell me I had it backward... which I now did, because my mentor had me switch things around.

My point? If you're going to suspect one piece of any research, suspect the statistics. Lots of times even the big scientific honchos don't know what they are doing and one little mathematical slip someplace can make a huge difference. If the work is important to you, look at the numbers that the statistics are derived from and see if the conclusion makes any sense.

The other piece of knowledge I derived about statistics from that period in my life was this: correlation does not equal causation. For instance, you might notice a strong correlation between school attendance and owning an MP3 player. You could reach the conclusion that people buy MP3 players because they go to school. That wouldn't be right, would it? It's more likely that people of school age are more likely to be interested in both music and technology... Next time you hear about a correlation between eating cheeseburgers and howling at the moon, you can take it with a grain of salt.

Links:

FedStats: Government statistics. You can probably trust them. Really.

A statistics textbook online.

A little shorter and easier explanation.

Word Of The Day

Margin of Error: Since the president elect used this phrase in his weekly address, I though it would be a good one to define. This represents how precise a number is. If the margin of error is small, that means the scientist is pretty sure she has it close. If it is large, there is a lot more "wiggle" in the number. This number is often used with the words, "plus or minus," in front of it. For instance, "the average grade of the class was 70%, plus or minus 20%." That's a huge margin of error. The actual average could be anywhere from an A to an F. You wouldn't want to have much faith in that number.

Umami

2009-01-10T01:00:00.000-08:00

(image from healthline.com)

I will cover cryobiology, a subject that came up in the comments last week, on Tuesday, but today I want to talk about something I came across a few weeks ago while listening to The Splendid Table on NPR (a cooking show).

The host talked about some mysterious taste called umami that I didn't remember ever having heard of before. Remember high school biology? The teacher had a giant tongue up on the overhead projector and pointed to various places on it. "This is where we taste sweet. Sour is hear, bitter is here, and salty is here. These are all the tastes."

Was I the only one thinking, "yeah right!"? I was properly indoctrinated though and I have found myself in front of groups of students with my handy dandy giant tongue, saying the same things. But, aha! There is another one. Those brilliant high school students knew it all along. (You suppose there might be other tastes hiding out on there that they haven't discovered?)

Umami means yummy(I don't speak Japanese and the experts said delicious but it sounds like yummy to me) in Japanese because the man who tracked this taste down to a chemical called glutamate was Japanese. If glutamate is sounding familiar to you, think MSG. Some people have a hard time with MSG and this taste seems to be triggered by all kinds of meats and cheeses, so what the food world really needs is a replacement for MSG that's more like the chemicals in meat that cause the taste.

That leads us to the receptor for the umami taste, which looks like (or would if you could see it) a very tiny venus fly trap. I only know that because the scientists named it the Venus Fly Trap Domain (there seems to be a venus fly trap domain involved with other kinds of receptors too). It seems to take two chemicals to cause this trap to snap shut. So far as I have been able to tell, nobody has put this taste on the map of the tongue yet and so I am unable to add it to my giant tongue transparency...

several reasonably reliable sources (including this one) tell me the map of the tongue is a myth anyway and you can taste most flavors all over the tongue. This seems strange to me since the professors in grad school had me teach a lab about this (and later I taught the same lab myself) to hundreds of students and it all seemed to work out fine... maybe college kids report what they think they are supposed to? I'm not going to repeat the experiment right now, but maybe I will later.

Links:

This paper is talking about Venus Fly Trap domains and allosteric control of agonistic affinity.

This Wired article is a lot easier to understand.

This article from Chemistry World shows us how chemicals work together to make the umami taste stronger.

Word of The Day

Agonist: A chemical that binds to a receptor and causes it to act in some way.

Jellyfish Revisited

2009-01-09T01:00:00.000-08:00

(Picture from this South Carolina Department of Natural Resources page.)

Janna (of The Jannaverse) asked these questions in the comments section of the jellyfish post last week and I'm going to try and answer them.

(I found lots of these answers at the above link.)

So each bud becomes a separate jellyfish?
No. It turns out that some buds can make more polyps and polyps can either live alone or in a colony that looks like big stem with lots of weird flower things on it. The buds for medusa look different that the buds for new, asexually produced, polyps.

How many buds are there on each polyp?
This varies widely.

After all the buds are broken off, does the polyp then die?
No. Some polyps can live for a very, very long time. The jellyfish normally don't live that long-A few months or so.

Do the polyps gather the same kind of food that the mini-medusa will eat later on?
What DO they eat?

Yes. Generally the polyps and the little medusa eat zooplankton. The grown jellyfish eat different things. Some species eat zooplankton their whole lives. Other's move on to bigger things like crustaceans. There are fish and other animals that prey on jellyfish too. Some kinds are eaten by people. Not this person yet, but some people.

Links:

The Zoo Aquarium in Berlin talks about what it takes to breed jellyfish here.

Video of feeding polyps. It's a little blurry.

Word of The Day

Zooplankton: microscopic animals that eat phytoplankton which are microscopic plants.

Astronomy

2009-01-08T01:00:00.000-08:00

(this is an illustration of the Milky Way from astronomypictures.net)

First, I want to thank Bob from Black holes and Astrostuff for alerting me to the fact that 2009 is the International Year of Astronomy. Check out the link to find out all about astronomical stuff going on all over the world this year. Also, visit Bob. He has some Hannah Montana 3-D glasses to give away if you happen to live in Ontario and stop by for his Year of Astronomy event.

Now, I heard the alarming news today that our galaxy might have only two arms. That got me thinking about how I know what the galaxy looks like and that led me to discover (Please forgive me here. I'm just a sign maker with a biology degree.) that all those pictures of the galaxy that I've seen are paintings. I mean, how are they going to take a photograph from outside the galaxy? They aren't. So how did the artists know what to paint? Astronomers told them.

Not only might the galaxy have only two arms, it's probably also a lot bigger and moving a lot faster than we thought. Here's the press release about the talk that astronomer Mark Reid gave at the meeting of the American Astronomical Society.

Links:

The Harvard-Smithsonian Center for Astrophysics

All About Mark Reid

The abstract for an article about cosmic masers

Word Of The Day
(in this case, phrase)

Cosmic Maser: I had a hard time with this one. I started with the word Maser, which turns out to stand for Microwave Amplification by Stimulated Emission of Radiation. What that means is that it's a microwave version of a laser, which, as far as I can tell, means that when you shoot microwaves at some molecules (gas molecules in this case) you make more microwaves. Cosmic, means that it happens out in the cosmos. The findings of the study I mention above were made using a radio telescope.