Science and technology week in Mexico

By Martín Bonfil Olivera

Published in Milenio Diario, October 28th, 2009

Each year, in October, science popularizers get our busiest season, because that's when the national Science and technology week is held in Mexico.

As a matter of fact, the demand for all kinds of activities –conferences, courses, workshops, expositions, science fairs, concerts, starry nights, contests…- its such that many states opt to enlarge it, turning it into the Month of Science and Technology – and some, into several months! – so competition is not that intense.

The event, promoted and organized by the National Council for Science and Technology (Conacyt), has for 16 years placed scientific culture in the reach of literally millions of kids, youngsters and adults all over the country.

This year the national venue was the state of Tabasco, where I have been able to attend several activities organized together by the state government, the Tabasco Science and Technology Council (CCYTET) and a good number of organizations and enthusiastic people who are engaged in science popularization.

But is it worth it, with all the economic crisis and our country's problems, to spend budget and work in such an event? Here are four good reasons to do it:

-Because the standard of life in a country depends strongly on the size of its scientific-technological-industrial apparatus. An good-sized, active scientific community detonates the production of original knowledge which become technology and patents that can make a modern and powerful nation. Think of the Korean cell phones, Indian cars and Chinese computers we import, or of the Brazilian technology for oil extraction that we're far of matching. And the first step is to awaken scientific vocations in kids and young people (and of course, to give them jobs in research institutes, but that's another story).

-Because the scientific way of thinking is a powerful tool in fighting harmful beliefs, such as the conspiracy theories that deny the seriousness of the influenza pandemia and the usefulness of vaccines in preventing infection.

-Because if the citizens do not understand the science behind matters such as cloning, euthanasia, transgenic crops or stem-cell research, they cannot take part in the decisions we as a society need to take.

-Because science and technology, as products of human creativity, are and endless source of amazement and great ways of having a great time. All citizens have the right to enjoy them.

For these, and many other reasons, long live the Science and Technology Week! I only wish it could last all year long.

(translated by Adrián Robles Benavides)

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An award for Cotija cheese

By Martín Bonfil Olivera

Published in Milenio Diario, October 21th, 2009

Last week we talked about the Chemistry Nobel prize, awarded for the solving of the structure of the ribosome, the cell's protein factory. Today let's talk about Cotija cheese.

There's a link. Bear with me: an investigator from the Chemistry School at the National Autonomous University of Mexico (UNAM), Dr. Maricarmen Quirasco, and her master's-degree student Alma Berenice Zúñiga, have just won the National Award for Food Science and Technology, given by Coca-Cola and the National Council for Science and Technology (Conacyt), a study in which they identify and characterize the main microorganisms that live in the Cotija cheese.

Microbes in a cheese? If you're a fan of this appreciated cheese, which has been hand-produced for 450 years by about 200 families in the Jalmich mountains, close to Cotija, Michoacán, you could worry about this. Don't. The study by Quirasco and Zúñiga seeks a better understanding of the manufacturing process of this aromatic and nutritive cheese (in another study, the same group discovered it has healthy antioxidant properties), in order to protect it and improve it.

The thing is, the production of almost any cheese needs the so called lactic bacteria, which turn milk sugar (lactose) into lactic acid. This increases acidity and causes the milk proteins to curdle, thus transforming into cheese. Many other dairy products, such as yoghurt, are also teeming with microorganisms.

But in the manufacturing of the Cotija cheese, made with non-pasteurized milk, there's an actual microscopic ecosystem living there, in which there is competition between species and survival . To study it, Quirasco and Zúñiga used modern molecular techniques: they studied the ribosomal RNA genes –the main component of ribosomes, here's the link– from bacteria. These genes are used to identify species because all cells have ribosomes; when comparing them, their differences are detected and make it possible to identify them.

The study revealed that, during the ripening process of the cheese, which takes from three months to one year, the competition wipes out all possible pathogen bacteria, which guarantees the cheese's hygiene. And the knowledge gainwill allow, in the future, to standardize the production process and to help manufacturers obtain the "denomination of origin" (Protected Geographical Status), with which they could fight unfair competition from "Cotija type" cheeses, some of them even coming from abroad, that are supplanting the original.

In other words: first-class food science, done at UNAM, that will benefit Mexican producers.

(By the way, you are not necesarily interested in this, but Maricarmen Quirasco and yours truly were together when studying pharmaco-biological chemistry at UNAM, and I admired her great intelligence and dedication to work since the time we studied at National High School number 6. Honestly, congratulations Maricarmen! Read her article of the Cotija cheese, here)

(translated by Adrián Robles Benavides)

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The amazing ribosome

By Martín Bonfil Olivera
Published in Milenio Diario, October 14th, 2009

The chemistry Nobel prize thrilled me even more than the one for Medicine.

It was given to Venkatraman Ramakrishnan (Hindu, nationalized American, but living in Great Britain), Thomas Steitz (United States) and Ada Yonath (Israeli) because of "their studies about the structure and function of the ribosome".

If, like I mentioned last week, enzymes are amazing molecular machines that practically carry out all the functions of a living cell, ribosomes are an real automatized factories that manufacture, with absolute precision, each one of the thousands of different proteins we need to be alive.

A ribosome is a complex structure made of ribonucleic acid (the one-strand cousin of DNA) and many proteins.

It has some fixed parts, and other that move with robotic precision to assemble, in a matter of minutes, and from reading the information coming from DNA, proteins made up by thousands of amino acids, strung together as pearls in a necklace.

The achievement of the Nobel winners was to localize with great precision each one of the hundreds of thousands of atoms that form a ribosome, and this has allowed them to understand their functioning in atomic detail. They used X ray crystallography, a technique developed in the beginning of the 20^th century (and the same one that allowed Watson and Crick to discover the DNA double helix structure in 1953 --a structure, I might add, infinitely simpler than a ribosome).

To achieve this, they first had to obtain perfectly arranged crystals formed by pure ribosomes. It took them almost 20 years.

But to see atoms, one cannot use an optical microscope, not even an electron microscope. Only X rays have the necessary finesse. And no lens can focus them to form images: you have to gather the group of stains formed as the X rays travel through the crystals (originally the stains were captured on photographic film, but today they are captured by a couple charged device or CCD, the invention that this year won the Physics Nobel prize) and using computers to mathematically process data.

The result? Computerized models that reveal, with a very high level of detail, each screw and bolt of these wonderful molecular nano-factories.

As an additional benefit, these models are allowing scientist to develop new antibiotics that work like monkey wrenches tossed into the ribosomes of bacteria that make us sick.

Yes, I loved this year's chemistry Nobel. Too bad that Harry Noller, one of the giants of ribosome research, was left out of the prize, which can only be given to three persons.

(translated by Adrián Robles Benavides)

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The Nobel telomere

By Martín Bonfil Olivera
Published in Milenio Diario, October 7th, 2009

Nobel prizes are always exciting. This year's Physiology or Medicine prize reveals fascinating basic science about our cells which might have revolutionary applications in health.

It was awarded, according to the Nobel committee at the Karolinska Institute in Sweden, "for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase", a discovery made by investigators Elizabeth Blackburn, her colleague Jack W. Szostak and her student Carol Greider.

The genetic information of living beings is written in the molecule of deoxyribonucleic acid, DNA, which form tangles called chromosomes within the nuclei on each of our cells.

Each chromosome is formed by a single, very long, DNA molecule. When it has to be copied, before the cell divides in two, the task is performed by an enzyme molecular machine made of protein.

Picture it like this: the famous DNA double helix is like a train railway. To copy it, both rails are separated and the enzyme slides over each one, reading the letters that form it and inserting the corresponding letters on the other side. Like a little train that advances in a rail, constructing the opposing rail. In the end, we have two complete and identical railways.

(http://www.youtube.com/watch?v=hfZ8o9D1tus)

But when the enzyme reaches the end of the rail, it cannot advance any longer, and does not construct the last span of the opposing rail. Each time that a chromosome is copied, their tips (telomeres, from the greek telos, end, and meros, part) would shorten!

Using a very ingenious experiment, Blackburn and Szostak discovered in 1982 that telomeres protect chromosomes so they are not destroyed. They constructed mini-chromosomes and added telomeres to some, but not all, of them. When they inserted the chromosomes inside cells, those with telomeres survived, but the ones that didn't have them were rapidly eliminated.

And in 1984 (Christmas day!), Blackburn and Greider discovered another enzyme that allows telomeres to maintain their size. It achieves it because it has a mold with the correct letter sequence (CCCCAA) that have to be inserted in each tip of DNA. They named it "telomerase" (the termination "ase" in biochemistry indicated an enzyme).

Today we know that telomeres and telomerase play a role in aging and cellular death (when telomeres are shortened) and influence the uncontrolled multiplication of cancerous cells (because their telomerase is very active and their telomeres are not shortened). There are even vaccines in development to try to fight cancer by inactivating the telomerase of tumors.

Basic science, motivated by simple curiosity, offers a new medical promise, although a far one.

(translated by Adrián Robles Benavides)

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