Medescape

Skepticism, Medicine and Science News

Fine Polish

Scientists have developed a new method of protecting teeth from bacterial attacks. By using technology from the semiconductor industry, Igor Sokolov  and hh from the Clarkson University Center for Advanced Materials Processing used  silica nanoparticles to polish teeth down to nanoscale roughness. When polished this finely, the bacteria had difficulties sticking to the dental enamel, and could thus be removed fairly easily. Polishing teeth is in itself not new, but no one has thought to use nanoparticles to do it before Sokolov and Gaikwad.  The study was published in the Journal of Dental Research

To the left, the unpolished surface of a tooth. To the right, the surface of a tooth after nanoparticle polishing. 

December 22, 2008 Posted by | Medicine | , , , , , , , , , , , , , , , , , , , | Leave a comment

The Perception of Pain

A recent study shows that pain hurts more of the person hurting you really means it (or rather, if the person being hurt believes the person really means it). The study was led by Kurt Gray along with Daniel Wegner, and published in Psychological Science

In the study, they paired up 48 participants with a partner who could either choose to give the other an electric shock or just play a audible tone for them. In the first set-up, the subjects received a shock when their partner chose this option (and to eliminate the factor of surprise, they were told in advance which option the partner picked). In the second set-up, the subjects were given a shock when the partner chose the tone, and vice versa. The resulting data showed that the subjects rated the pain from the intentional shocks significantly higher then that of the unintentional ones. This suggests that the perception of pain is closely tied with emotion, and that the latter can influence the first.

December 21, 2008 Posted by | General Science, Medicine, Psychology | , , , , , , , , , , , | Leave a comment

Thinking Clearly

A new study published by researchers at North Carolina State University shows a correlation between high blood pressure and decreased cognitive abilities in seniors. This could indicate that stressful situations may make it more difficult for seniors to think clearly. In the study, the researchers looked at persons with a systolic blood pressure of >130 mmHg. When their blood pressure spiked, it was accompanied by a decrease in cognitive function. The study was published in the Journal of Gerontology: Psychological Sciences.

December 17, 2008 Posted by | Medicine | , , , , , , , , , , , , | Leave a comment

Water Droplets And Black Holes

Researchers at the University of Nottingham have published a paper where they use water droplets to simulate the dynamics of black holes. By using magnetic fields and electrodes they managed to spin levitating water droplets, and this produced some interresting results. As the droplet was spun at different velocities, the shape changed to form, among others, triangles,  squares and pentagons. This was due to the surface tension of the water droplet, and the scientists say this is very much like what happens at the event horizon of a black hole. The droplet experiment could hence be used to model such systems, a valuable tool in learning more about the dynamics of black holes. 

There is a video of the dropet spinning here

You spin me right round, baby. 

December 15, 2008 Posted by | Physics | , , , , , , , , , , , , , , | 1 Comment

Gravity Fingers Mathematically Explained

Since I have my math exam tomorrow, it seems only natural I should write about something math related. 

When water soaks down into the ground, it does not do so evenly, but rather forms spikes known as gravity fingers (see image below). Though it is a well known phenomenon in fluid mechanics, no one has been able to explain, mathematically, why it happens. In a recently published paper however, mathematicians at MIT give a both simple and elegant explanation. They got the idea when one of the researchers observed that gravity fingers looked very much like water flowing down a window (when you look at the picture it looks really obvious, it was definitely the first think I though of), which is a well understood phenomenon. Then it was just a matter of taking the equations describing that and apply it to water movement in soil. 

The short explanation to this phenomenon is that in order for water to flow down a window or in soil, the surface tension of the water has to be overcome. This will cause the water to flow in a finger-like pattern because as water builds up in the fingers, the weight overcomes the surface tension. My understanding of the phenomenon is that small indentations in the bottom flow line are bound to form no matter what because the soil/window is not perfectly uniform (and can never be), and when this happens the flow rate at the indentations increase because of the extra weight, leading to gravity fingers. 

Gravity fingers

December 14, 2008 Posted by | Math | , , , , , , , , , , , , | Leave a comment

Aquamantra

This is just too funny. Aquamantra is a brand of bottled water sold in the US, but it’s not really the water that is special about this particular brand. Oh no, the labels on the bottles have mantras on them, and this, according to the company’s web site, causes the water inside to resonate with the energy and frequency of the mantra in question. Yeah…. Whenever you see people using quantum mechanics to explain something “scientific”, 10 to 1 they are just full of s***. Just listen to this:

[Dr. Masaru Emoto ]showed us the basic principles of quantum theory, whereby the molecular structure of water was changed by a Zen Buddhist monk’s thought. Based on this premise, Aquamantra uses the design on its labels to affect the molecular structure of California natural spring water[…]

Sure. That sounds perfectly reasonable. 

Our bodies were designed to live 200 years, can you live that long with out Aquamantra?

200 years? Wow, I never knew! 

The message comes from the universe, love yourself, deliver unto yourself perfect health. From the intense sky, a sparkling stream of water shares with you its secrets and the waterfall brings the messages of perfect health.

Fantastic. If you want to look it up, just do a search for Aquamantra. 

December 13, 2008 Posted by | General Skepticism | , , , , , , | 2 Comments

Watch The Moon Tonight

Tonight, on Friday December 12th, the full moon will be bigger than it usually is. This is because its orbit will take it nearly as close to earth as is possible. The earth-moon distance is, on average, about 384,400 km, but tonight is is much closer, at about 356,567 km. Not since 1993 has the full moon been this close to earth, and it will take another 8 years before it happens again. Compared to the other full moons in 2008, this one will be 14% bigger and 30% brighter than any of them. So, get out and take a look. 

December 12, 2008 Posted by | Astronomy | , , , , , , , | Leave a comment

LHC: Damage Report

Earlier this year the Large Hadron Collider was fired up, but sadly it did not take long before it broke down. In fact, only nine days after the opening CERN was forced to shut it down again due to an accident during one of the test runs. An electrical connection melted, which subsequently led to failures in the pipes containing liquid helium. Because the superconducting magnets require temperatures at about -271°C (that is only about 2 kelvins!) to function properly, they failed dramatically when the helium cooling system was damaged. When the magnets started overheating, they damaged nearby equipment with a massive burst of pressure. The forces at play were so great that several of the magnets supports were literally ripped from the ground were they were secured. 

But, they say they will be able to fix the problem, an have the LHC up and running again next summer.

December 11, 2008 Posted by | Physics | , , , , , , , , , , , | Leave a comment

Remember To Set Your Clocks!

This coming New Years Eve everybody needs to remember to change the time of their clock….by one whole second. It sounds daft, but this happens every three years because the earth gets too out of sync. When the clock strikes 00:59:59 on New Years Eve,  make sure to pause time for about one second, and then let it strike 01:00:00. The insertion of this leap second was prescribed by the International Earth Rotation Service in Paris due to the fact that the earth tends to lag behind the extremely precise atomic clocks. So, happy leap second-year!

December 10, 2008 Posted by | General Science | , , , , , , , , , | Leave a comment

Fat Busting Enzyme

Scientists have discovered a mutation in a roundworm that causes them to rapidly burn fat, and they say this could lead to new ways of treating obesity. The study was done at McGill University, and published in Nature

The roundworm in question is of the species Caenorhabditis elegans, a small creature only about 1 mm in length. When little food is available, they go into a sort of hibernation state called dauer. During this state they drastically alter their metabolism by shutting down energy consuming processes such as cell division and reproduction. As opposed to normal hibernation though, the worms are able to move around when in this state due to a special storage of lipids. This extra lipid reserve allows the worms to stay in the dauer state for as much as 6 months, which is considerably more than the estimated 2 weeks they would otherwise have managed. 

The newly discovered mutation in some of the ringworms has a considerable impact on their metabolism in dauer, and these worms were shown to die within a week of entering the state. The main reason for this is that they fail to regulate the catabolism of the lipid storage, and thus burn all of it within a few days. This is due to the lack of an enzyme that normally blocks the activity of an important triglyceride lipase, a class proteins that catalyse the hydrolysis of lipids and thus the catabolism of them. The thinking is that the regulating role of this enzyme may translate to humans, and that the faliure of this protein to function properly may lead to increased accumulation of triglycerides and thus lead to obesity. The researchers also believe that it may be possible to develop a drug that inhibits this regulatory enzyme specifically in fatty tissue, and in this way increase the catabolism of triglycerides and decrease patients weight.

It all sounds very similar to what we can achieve with uncoupling proteins. Most of a cells energy (in the form of ATP, or adenosin triphosphate) is generated in the mitochondria by using a generated proton gradient over the inner membrane. When these protons are brought back into the matrix of the mitochondria, they drive an enzyme that generates ATP from ADP (adenosin diphosphate) and a phosphate molecule. Uncoupling proteins are lipophilic proteins that bind to the protons in the intermembrane space and carry them over the inner membrane without driving the ATP-generating enzyme. This means that the energy from proteins, fats and carbohydrates disperses as heat, and is not used to generate energy that the cells can take advantage of. This could rapidly lead to an extreme shortage of energy, a potentially lethal state. One such uncoupling protein is 2,4-Dinitrophenol. Discovered in the 1930s, it is still used by some as a dieting aid and a quick and fast method of loosing body fat. This could cause serious problems though, such as hyperthermia and energy shortage. Not something I would advise taking. 

But, if a drug were developed that worked solely in fatty tissue and could be easily controlled, it could very well be extremely useful in treating obesity. 

Caenorhabditis elegans

December 9, 2008 Posted by | 1 | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | Leave a comment