Monday, May 25, 2009

Think Vitamin Supplements are Beneficial? Think Again!

by Alexandre Couto de Andrade

Free radicals are believed to contribute to the aging process. This is one of the main reasons why many people take antioxidant supplements such as vitamins C and E. Nevertheless, a German study suggests that these vitamins might actually shorten life through a yet unknown mechanism. A possible explanation for this fact is that free radicals might help the body prevent cellular damage after exercises.

Its worth noting, however, that when you get these vitamins through vegetables and fruits, the effects on your health seem to be good. This possibly happens because food contains other compounds that can exert a protective effect against the damages caused by the antioxidants. Besides, the supplements generally contain much higher doses of vitamins than those found in food.

Reference: “Vitamin supplements may cut benefits of exercise” (by Linda Geddes - New Scientist - issue 2708)

Sunday, May 24, 2009

Bizarre Animal Behavior

I have selected some videos from the National Geographic and BCC You Tube channels that show very bizarre cases of biological interactions between different species of animals. They show exotic parasites and parasitoids, as well as cases in which one animal makes slaves of others. It is really interesting.

2012: The End of the World (Again)?

By Alexandre Couto de Andrade

"Our earth is degenerate in these latter days. There are signs that the world is speedily coming to an end. Bribery and corruption are common."

Have you ever heard or read anything like the statement above? Does it seem familiar to you? Well, if you have been living on Earth for a while, it certainly does. This particular statement is nearly five thousand years old. It was found inscribed upon an Assyrian clay tablet and is the oldest known doomsday prediction. It is very probably not the first one ever. We cannot be sure. One thing, however, is certain: people never ceased to make predictions like this ever since. The website “A Brief History of the Apocalypse” provides a list of more than 250 dates on which the world should have ended according to the most relevant prophecies. Take a look. It is worth reading.
Some doomsday prophecies are simply ridiculous, while others are elaborate and have probably sounded very convincing to many of those who heard them. Many of them were pronounced by eminent religious leaders or written in sacred books. In some cases, the predictions were made when the circumstances really suggested that humankind was on the path to imminent self-destruction (the Jehovah's Witnesses, for example, viewed World War I as the Battle of Armageddon). Some predictions were purely mystical, while others were supposed to be “scientific”, at least in some degree. All of them, however, have something in common: the facts they foretold have obviously never occurred.
My purpose in this post is to write about the most recent of these prophecies: the 2012 doomsday prediction. Based on the Mayan calendar (Long Count), some people believe that the world will end on December 21 or 23, 2012. That's when the calender ends. This apocalyptic interpretation is disputed by academic scholars of Mayan civilization.
Pseudoscientists and mystics generally have very peculiar opinions about ancient civilizations. Many pseudoscientists simply underestimate them. According to Erich von Däniken, for example, the ancient egyptians needed extraterrestrial help to build the pyramids (a claim supported only by ignorance). Other pseudoscientists, as well as most mystics, on the other hand, overestimate them. Myths and superstitions are seen as “ancient knowledge”. Vague and obscure “prophecies”, that can mean almost anything (Nostradamus', for instance), always find a convenient interpretation (generally after the “foretold” event has occurred). That is clearly what happens in this case. How could the Mayans possibly have determined when the world is going to end? What kind of special knowledge did they have?
The proponents of the 2012 doomsday are not intimidated by questions like these. There are “other evidences”, after all. They are provided by astrology. Well, if you think that astrology is credible, read my first blog post (Astrology: What does Science have to say about it?).
Some people also argue that the wars, famine, natural catastrophes, diseases, among many other misfortunes that the world faces nowadays are signs that indicate that the end is indeed near. But haven't these problems always been with us? As a matter of fact, although things are still very far from being good, humankind has never been so prosperous as it is now.
We, human beings, will undoubtedly eventually face extinction. Nevertheless, the end is neither written in the stars, nor was predicted by any primitive people.

Sunday, May 17, 2009

The Worsening Climate Crisis

In a recent talk at the TED 2009 conference, Al Gore showed updated information about the alarming effects of global climate change.
Watch the video below.

Saturday, May 16, 2009

“Genocide never again”?

I have just watched the impressive The Devil Came on Horseback (by Ricki Stern and Anne Sundberg). It is a documentary on the Darfur genocide, based on the book by Brian Steidle, a former U.S. Marine Captain who worked in Sudan as an unarmed military observer.

Almost as shocking as the genocide itself is the incredible fact that nearly no one does anything to stop it. Some even deny the facts.

Watch the trailer and access the Save Darfur organization website. We can do something about it!

Sunday, May 10, 2009

The Seven Basic Principles of Magic

Human perception is not as reliable as we might think. The brain takes shortcuts to handle the overwhelming quantity of information constantly provided by the senses. That creates blind spots and other perceptual illusions that are intuitively exploited by magicians to fool their audience.

No matter how intricate magical tricks can be, magicians always rely on the same set of principles: palm, ditch, steal, simulation, load, misdirection, and switch.

In the first video below, magicians Penn and Teller show how it is done.

In the second one, magician James Randy shows how Uri Geller's “psychic powers” probably really work.

Sunday, May 3, 2009

The Survival of the Fittest... Molecule

by Alexandre Couto de Andrade

After Charles Darwin's “On the Origin of Species” was published in 1859, the way in which we human beings see ourselves has changed dramatically. Like Copernicus and Galileo before him, and like Freud (in spite of his pseudoscientific theories) and Einstein some decades later, Darwin started a scientific revolution. When it comes to answering the “big questions” of life and existence, few scientific theories or discoveries where so significant as “Evolution”.

Since then, numerous discoveries, made in various knowledge fields, have corroborated and increased our understanding of the theory of Evolution. Gregor Mendel, for instance, provided us with the knowledge necessary to understand how hereditary characteristics are transmitted from parents to offspring. In the beginning of the third decade of the 20th century, Alexander Oparin developed a theory that explained how the early Earth atmosphere and primordial ocean created conditions to originate life. In 1952, the Miller-Urey experiment succeeded to synthesize amino acids in the conditions imagined by Oparin. Nowadays, the Genome Project is almost literally writing the history of life, offering an overwhelming quantity of evidence that confirm the theory of Evolution.

This week, an article published in the online edition of the journal Proceedings of the National Academy of Sciences (PNAS) describes the work of Sarah Voytek, Ph.D. , who created RNA molecules that evolve and compete with each other for resources. Her work not only confirms Oparin's idea that organic molecules can compete with each other, but also reveals the mechanisms of the resulting natural selection.

I transcribed below part of the article's abstract:

Mixed populations of 2 different 'species' of RNA enzymes were made to compete for limited amounts of one or more substrates, with utilization of the substrate being necessary for amplification of the RNA. Evolution in the presence of a single substrate led to the extinction of one or the other enzyme, whereas evolution in the presence of 5 alternative substrates led to the accumulation of mutations that allowed each enzyme to exploit a different preferred resource”.

Click here to know more about it.

Saturday, May 2, 2009

Wine Tasting for Laymen

If you love wines but do not yet know how to taste them, the two videos below will be helpful for you.

In the first one, you will learn the basics of red wine tasting. The second video is about both white and red wines.

If you want more comprehensive information, click here to get access to the Wine Spectator's “ABC of Wine Tasting”.