JZ Blog: My Science Reading

China Disappoints Me Once More

2010-01-15T17:58:00.000-08:00

Google is leaving China, my home country, which I left about 2o years ago, a couple of years after the Tiananmen event.

My China is the old China, no matter how much economic development she has enjoyed since I left.

China, Still a Pre-Scientific Society

2006-12-06T18:57:00.000-08:00

China was one of the most advanced nations in the world, when most of them were agricultural. Actually, China was one of the only handful of regions that independently developed agriculture on earth, at around 10 to 8 thousand years ago.

The earliest agriculture was invented about 12-1o thousand years ago, in nowaday Middle East. The agricultural expanded outward following population growth as an outcome of agriculture, into most of Europe and the rest of West Asia. Farmers and agriculture spread much slower than industry and were stopped by high mountains in central Asia. About 2 thousand years later, China independently invented the agriculture. Farmers in China also spreaded outward, to as far as Tibet and Southeast Asia.

At its core region, the Yellow River and Yangtze River regions, the advantage of inventing agriculture persisted even after thousands of years of agriculture development. That's why China, not other countries dominated East Asia and South East Asia for so long. That's also why Arab civilization dominated Middle East for centuries.

Things changed only after human being invented another completely new way of living - industry, backed by modern science, a new way of thinking. West Europe and its decendent - North America, has dominated human civilizations ever since then. Although Arab and China seemed have implemented lots of things invented by West Europe, such as industrial infra-structures, "laws", and modern universities, they are still, deep in their hearts, pre-scientific societies.

Resveratrol and Drug Discovery

2006-12-05T12:31:00.000-08:00

Resveratrol, whose chemical structure is shown on the left, is not a house-hold name yet. But it may very well be one, maybe in a year or so. Published data demontrated that it could extend the life-span of yeast, worm, fly, fish, and mice up to 20-50%. At such a grand evolution scale, it seems to me its effect on human should be very promising.

The mechanism of resveratrol was proposed to involve an enzyme called sertuin, which removes a acyl group (CH3CO-) from an acyl-lysine sidechain in a protein. Cell uses the acylation/deacylation, much in the same way as phosphorylation/dephophorylation, to regulate many crucial activities. The physical basis all involve introduce/eliminate a charge in a protein so that a significant reorganization of the protein structure would take place and thus function differently. The enzyme needs help from NAD+ in order to do the job, a mechanism nature has designed to link the acylation/deacylation to metabolism. That's because NAD+ and its reducing form NADH, especially their concentration ratio reflects how well an animal is fed - more NADH means more food, vice versa, because the energy in the food is converted to the reducing power of NADH, which is then used to reduce O2 gas breathed in to generate energy that every cell can use - ATP. Resveratrol was shown to increase the activity of sertuin, thus mimicing the effect of increasing NAD+/NADH ratio, thus mimicing the starvation condition, the only proved way of extending life span of a primate. Most of the research I presented in the paragraph came from a Harvard group. So far so good.

But some scientists disagree the above mechanism - one group from U of Minesota and another one from U of Washington. They said the effect of resveratrol is ARTIFICIAL - it only increase the sirtuin activity when the artificial substrate - a peptide embeded with an fluorophore. Their data is frustating for those who like to extend their life or their youth life by taking resveratrol. Of course, resveratrol could still have effect even though its mechanism through activating sirtuin proves to be wrong. Other posible mechanism includes well-known anti-oxidant. So far, I am unable to tell who is right who is wrong.

Mars Global Surveyer is Lost

2006-11-28T19:31:00.000-08:00

This is such a sad story that took place a couple weeks ago. I was constantly looking for updates on NASA and JPL's website after a week of silence because signal block between Earth and Mars by the Sun. All of a sudden, bad news came to my attention that MGS was lost when NASA wanted to recontact it after it came back from behind the Sun.

Even though it is an "aged" craft - 10 years of service around Mars, sending back thousands of pictures, I still felt sad about its loss. NASA tried very hard several times to regain control but failed in the end. I was touched when I read that one NASA scientist called MGS, a longtime friend and teacher. It really is our teacher.

The Beauty of Molecule

2005-09-15T13:40:00.000-07:00

All matters in the world are made of limited types of atoms through their limitless ways of combinations, called molecules. For example, the table sugar are crystals of sucrose molecules, i.e. enormous numbers of sucrose molecules organized in a repetitive three-dimensional lattice. When a spoon of tiny sucrose crystals is put into water, the lattice collapses and single sucrose molecule enters a sea of water molecules, surrounded by them, a process called dissolution. There are only three types of atoms in a sucrose molecule, carbon, oxygen, and hydrogen. Actually, these three types of atoms plus nitrogen, phosphorous form most of the molecules in our body.

Let's talk about nitrogen. Two nitrogen atoms form a nitrogen gas molecule, countless numbers of which enters your lung each time you breath in air. They do not really enter your body, however; they are breathed out. The molecules enter your body are oxygen gas molecule, formed by two oxygen atoms. So, where do the nitrogen atoms in our body come from? The only way is the food, not in the form of nitrogen gas, but mainly in the form of protein. Not only we cannot use nitrogen gas, neither can the majority of animals and plants.

A small group of microbes that do have the capability of directly using the nitrogen gas produce a very special enzyme (a protein molecule that act as a catalyst, which speeds up conversions of other molecules), called nitrogenase. Nitrogenase speeds up the conversion of nitrogen gas molecule to ammonia molecule, well, actually makes the conversion possible by coupling it with consumptions of a universal biological energy-bill, a molecule called ATP. ATP contains three phosphorous atoms linked energetically by two oxgen atoms, respectively, i.e. lots of energy is released if the link breaks, usually by intervening of a water molecule.

To be able to do this difficult job, so called nitrogen fixation, Nature has built nitrogenase into a very complex molecule. In the last decade, scientists have gained unprecedented insights into how the complex molecular system carry out the difficult job. A recent issue of Science published another milestone paper that will help we human being to understand the beauty of those wonderful molecules.

Looking Back at Our Moon

2005-09-14T20:25:00.000-07:00

NASA's latest exploration spacecraft to Mars (MRO) is now 6 million miles away from Earth, when it stretches its muscle, pointing its high resolution camera at our Moon. At this distance, assuming we are in the MRO, the Moon would be as small as a shiny star. But to MRO's high resolution camera, what it saw was a beautiful crescent shown above. Once it is in Mars orbital, it is going to discern a Martian object as small as a coffee table! Using this wonderful camera, NASA hopes to locate the ill-fated Mars Polar Lander and another ill-fated lander made by Europian Space Agency.

My Awe towards a Spectrum, a Martian One

2005-09-07T13:02:00.000-07:00

I had never been awed by anything, not even the most beautiful and weirdest creatures in the Monterey Aquarium. However, I was completely speechless the moment I first saw, about one and a half years ago, the above Mossbauer spectra taken by a NASA robotic geologist, opportunity, on Mars. Mossbauer spectroscopy is good at deciphering the finest details of iron-containing compounds (minerals). And the above graph compares the Mossbauer spectra of two spots scores of centimeters apart on a Martian rock, hundreds of millions of miles away from Earth! One spot, which holds much of the little rounded pebbles, is much richer in hematite, than the other. On Earth, hematite formation mainly involved water and thus the above spectrum is one of the most convincing evidence of past liquid water on Martian surface!

The Mossbauer spectrometer that made this discovery was built by a group of German scientists. This reminded me of a German post-doc in our lab, who failed to correct our spelling of the word Mossbaur. Anyway, good job!

Translation Means a Lot

2005-09-06T19:47:00.000-07:00

I went to college in the late '80s in China. In addition to various textbooks, the university bookstore were full of translational "masterpieces" at that time. While I was reading college physics, chemistry, and biology textbooks, many students were "reading" those translational "masterpieces", e.g. "Entropy", "Post-Modernism", etc. etc. I tried several times to read a few, only to embarrass myself as I usually gave up before finishing the first chapter. I couldn't tell what went wrong. "The topics are too advanced for me?" I would utter to myself, after each failure.

Fifteen years later, finally I know why, thanks to some of the detailed investigations done by Dr. Fang at Xinyusi. It was the bad translation. What Dr. Fang showed was that, many Chinese versions of some of the most famous scholarly book were so poorly transtlated that they are simply incomprehensible by Chinese readers. The examples include, very unfortunately, "Consilience: the Unity of Knowledge" by Edward I. Wilson, "Evolution: the History of an Idea" by Peter J. Bowler, both "translated" by Tian Min. Most of the translators neither hold an advanced degree nor lived (for an extended period of time, not just visiting) in the western countries. Therefore, they have neither the language skill nor the technical background to fulfill the difficult job of translation.

Before finishing this post, I would like to give links to two of my recent translations, both of which were published in a Chinese on-line journal: Our Science.

"Crick's Immodest Ambitions", a Nature Editorial: Original, Chinese
"Science and the Nature of Awe", by Rudy Baum of C&EN: Original, Chinese

"My role is different."

2005-09-05T21:48:00.000-07:00

A little bit of politics.

Maybe because I almost had a chance to be a TA of their daughter, I, being a conservatist in my heart, like Clintons very much. NYTIMES published a news article today, discussing Clintons' role in dealing with the aftermath of hurrycane Katrina. While President Clinton is more diplomatic than political, saying "It's an appropriate thing to look into, but not at this time - they're still finding bodies there"; Mrs. Clinton said, in refering to her husband: "He is a former president with an enormous amount of influence and just as during the tsunami, he is willing to serve his country. He has expressed strong feelings about the way this has been handled. My role is different. I'm on the front lines dealing with these issues day to day."

I think she will be a great President if she gets elected in 2008.

More on Chimps in Science

2005-09-02T23:25:00.000-07:00

Even though all the latest genomic research papers on chimpanzee were published in Nature, Science published several great articles too, celebrating the wonderful accomplishment in genetics and anthropology. The collaboration between these two journals is amazing! The Science chimp articles include one Editorial, advocating the preserving endeavours of great apes; one Perspective, introducing the genome paper in Nature and other aspects of chimp research; and serveral other news articles. Obviously, the Science editors are excited at it too! Unfortunately, you need a password to read all those articles.

Chimps, Chimps Everywhere

2005-09-01T21:18:00.000-07:00

Nature's web site has a wonderful collection of papers about chimps, and they are all free. You don't need a password to read them and I promise they are fun to read.

Microsoft bought Teleo, a VoIP company and will supply computer-to-line phone service by the end of the year. When will Google Talk do the same thing? I hesitate to download MSN and Skype.

First blog post

2005-08-31T20:01:00.000-07:00

I am going to use this page to summarize my readings of science on the web, from popular science to somewhat more professional reading. Although my professional training is at the interface between chemistry and biology, more than 50% of my reading of science on the web is about something else, e.g. human evolution, space exploration, information technology, and etc.

First, about space exploration. NASA is sending another orbitor to Mars, which was launched Aug 12. When I was trying to get the latest news about it, I found there are several sites on NASA, JPL, and etc, which update themselves differently, and I think, confuses people. Also, one thing missing on those sites is a link called "Where is MRO now?". A similar link was used frequently by me when I was following the trajectories of two famous Mars landers, Spirit and Opportunity.

News today on human evolution include the following:

The 1st chimp fossil was found in East Africa and reported in the most recent issue of Nature. This is exciting because in contrast to numerous findings of fossils of human ancestors since splitting from the human/chimp common ancestor (which happened around 6 million years ago), no fossil was found for the chimp ancestors at all, until now.

The chimp genome sequencing has completed and the result was again published on Nature. The identy with us is 96%. The difference is mainly within the neural system and the reproduction system. I feel the former is expected but the latter is less comprehensible.