Archive for the ‘Fai's sharing’ Category

Why Roosters Have Wattles?

Wednesday, November 4th, 2009

From Smithsonian.com

The test hens responded more quickly to the tidbitting males that had the normal or stationary wattles, less quickly to the one with the extra floppy wattle (….) and slowest to the male lacking wattles. After the hen’s attention was gained, though, she reacted about the same to each of the four animated chickens. Smith suggests that the wattle helps a rooster gain a hen’s attention when he is tidbitting, rather like a human guy wearing flashy clothes while doing his best dance moves to try and pick up chicks.

The Nobel Prize in Physiology or Medicine 2009

Monday, October 5th, 2009

goes to Elizabeth H. Blackburn, Carol W. Greider, Jack W. Szostak.

“for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase”

link to Nobel prize.org

link to the press release

2009 Ig Nobel prize winners!!!

Friday, October 2nd, 2009

Some interesting work here, the full winner list is available from their website:

PEACE PRIZE

Stephan Bolliger, Steffen Ross, Lars Oesterhelweg, Michael Thali and Beat Kneubuehl of the University of Bern, Switzerland, for determining — by experiment — whether it is better to be smashed over the head with a full bottle of beer or with an empty bottle.
REFERENCE: “Are Full or Empty Beer Bottles Sturdier and Does Their Fracture-Threshold Suffice to Break the Human Skull?” Stephan A. Bolliger, Steffen Ross, Lars Oesterhelweg, Michael J. Thali and Beat P. Kneubuehl, Journal of Forensic and Legal Medicine, vol. 16, no. 3, April 2009, pp. 138-42.

VETERINARY MEDICINE PRIZE

Catherine Douglas and Peter Rowlinson of Newcastle University, Newcastle-Upon-Tyne, UK, for showing that cows who have names give more milk than cows that are nameless.
REFERENCE: “Exploring Stock Managers’ Perceptions of the Human-Animal Relationship on Dairy Farms and an Association with Milk Production,” Catherine Bertenshaw [Douglas] and Peter Rowlinson, Anthrozoos, vol. 22, no. 1, March 2009, pp. 59-69.

ECONOMICS PRIZE

The directors, executives, and auditors of four Icelandic banks — Kaupthing Bank, Landsbanki, Glitnir Bank, and Central Bank of Iceland — for demonstrating that tiny banks can be rapidly transformed into huge banks, and vice versa — and for demonstrating that similar things can be done to an entire national economy.

MEDICINE PRIZE

Donald L. Unger, of Thousand Oaks, California, USA, for investigating a possible cause of arthritis of the fingers, by diligently cracking the knuckles of his left hand — but never cracking the knuckles of his right hand — every day for more than sixty (60) years.
REFERENCE: “Does Knuckle Cracking Lead to Arthritis of the Fingers?”, Donald L. Unger, Arthritis and Rheumatism, vol. 41, no. 5, 1998, pp. 949-50.

LITERATURE PRIZE

Ireland’s police service (An Garda Siochana), for writing and presenting more than fifty traffic tickets to the most frequent driving offender in the country — Prawo Jazdy — whose name in Polish means “Driving License”.

MATHEMATICS PRIZE

Gideon Gono, governor of Zimbabwe’s Reserve Bank, for giving people a simple, everyday way to cope with a wide range of numbers — from very small to very big — by having his bank print bank notes with denominations ranging from one cent ($.01) to one hundred trillion dollars ($100,000,000,000,000).
REFERENCE: Zimbabwe’s Casino Economy — Extraordinary Measures for Extraordinary Challenges, Gideon Gono, ZPH Publishers, Harare, 2008, ISBN 978-079-743-679-4.

Biotechnology Mobile Laboratory Education Program in Hong Kong

Saturday, September 12th, 2009

Dr. William Mak, a good friend and a great role model, has been devoting his career to improving the biotechnology education for primary and secondary students and teachers over the years. He has established the Hong Kong Biotechnology Education Resource center with Sik Sik Yuen Ho Yu College and built a university-level research laboratory to facilitate the process. He has been working on another interesting project recently – a custom-built coach bus that serves as a mobile laboratory for the community. He made me feel proud to be a Hong Kong scientist.

More information can be found here:
http://www.hkberc.org.hk/
http://biotechmobilelab.hkberc.org.hk/

Here are a few pictures of my visit…

Placebos Are Getting More Effective.

Thursday, August 27th, 2009

Placebos Are Getting More Effective. Drugmakers Are Desperate to Know Why.

from wired magazine.

Is that blue or green?

Sunday, July 19th, 2009

They are the same.

Here is how your brain done this.

A lesson learned from a regeneration study

Wednesday, July 15th, 2009

We have briefly touched the subject of stem cell research in the last journal club. The challenge of developing “stem cell” as a useful therapy is three fold:

  1. Turning the clock of a differentiated cell back to the very beginning.
  2. Guiding the resulting dedifferentiated “stem cells” or any kinds of “stem cells” to develop into the appropriate cell types.
  3. Incorporating these new cells into the existing organ system properly.

In one sense, the premise of 1 and 2 is that 3 would happen automatically once you can get the Stem cells. They are not only expected to become the desired cell type, but also are expected to know what to do inside the body. This can be a tall order.

There is actually a lot to learn from basic research to see how mother nature deals with the regeneration problem. Salamander is a great regeneration model. If you cut its limb off, the cells in the wound region will grow back a limb to its entirety.

It has long been thought that these cells that are responsible for the regeneration process are pluripotent, or “stem cell”-like. A very interesting research has proven it is otherwise. The original cells in the limb actually remember their identities, and they will only grow back to their own kind. In other words, muscle cells will become muscle cells, and skin cells will become skin cells.

460039a-f2.2

It looks like that instead of having some very specialized stem cells that switch all the way  back to the beginning, the differentiated cells just go back a few (?) steps and maintain their identities during the process. One wonders how this process is regulated at the network level and what has been lost in us that we do not have this capability anymore. Maybe this talent is still hibernating somewhere in our genome, waiting for us to turn it back on.

References:

Sánchez Alvarado A. A cellular view of regeneration. Nature. 2009 Jul 2;460(7251):39-40. [PubMed][Nature]

Kragl M, Knapp D, Nacu E, Khattak S, Maden M, Epperlein HH, Tanaka EM. Cells keep a memory of their tissue origin during axolotl limb regeneration. Nature. 2009 Jul 2;460(7251):60-5. [PubMed][Nature]

The scientists behind the Meselson-Stahl experiment

Tuesday, June 30th, 2009

The other day we talked about the historical moment when Matt Meselson and Frank Stahl elucidated the semi-conservative mechanism of DNA replication.

We briefly discussed the challenges that they faced at that time as a graduate student and a postdoc, which I think would give us insights to face our own challenges. I am still reading the longer book about the history behind this experiment. I think it is a very entertaining read but it is also very thick. A shorter historical account published in the PNAS would be easier for many of us to get an overall impression of the story.

References:

Hanawalt PC. Density matters: the semiconservative replication of DNA. Proc Natl Acad Sci U S A. 2004 Dec 28;101(52):17889-94. [PubMed][pdf]
Holmes FL. Meselson, Stahl, and the Replication of DNA: A History of ‘The Most Beautiful Experiment in Biology’ [Amazon]

A good review paper on the architecture of retina

Friday, June 26th, 2009

I read several classic papers when I am planning projects with some of you. This is a very good review paper on the fundamental architecture of retina. There are a lot useful histological facts and observations. It has great discussions on how the retinal architecture has evolved and in turn provides the necessary visual functions to the animal. I believe you will also find this review paper useful.

Reference

Masland RH. The fundamental plan of the retina. Nat Neurosci. 2001 Sep;4(9):877-86.[PubMed][Nat Neurosci]

In the Light of Evolution III: Two Centuries of Darwin – Sackler Colloquium

Monday, June 22nd, 2009

This is a series of papers from a recent Sackler colloquium of the National Academy of Sciences entitled “In the Light of Evolution III: Two Centuries of Darwin“. You can watch most of the presentations online here. The conference papers are published in a supplemental issue of the PNAS.

I read Daniel Dennett’s paper because of my personal interest. He is a philosopher in science. In his paper, he provides a simple overview on why it is not necessary to have an intelligent designer to make complicated biological machines.

Reference

Dennett D. Darwin’s “strange inversion of reasoning”. Proc Natl Acad Sci U S A. 2009 Jun 15. [PubMed][pdf]