Thursday, November 30, 2006

Teaching tip #3: Spot the thermometer student

In a classroom it is sometimes difficult to know in real time if the students are receptive to what you say. Maybe they do not grasp what you want them to. Well, there might be hope...YES! In a classroom, some *students are more expressive than others, their body language is more obvious although they are not aware of this. Spot these students early and look at them every time you think something might be difficult to understand. Their frowning might indicate a problem...if so, repeat your concept from another angle and then ask if it is works everytime! By the way, I call them my "thermometer students".

*PS. Do NOT tell them as they might become self conscious and you could lose their subconscious collaboration.

The biological problem with binge-drinking

Binge dinking is not a new phenomenon...especially with college students. These parties can last for days, an the impact on academic success is often dramatic resulting in failures and, lets face it, money loss.

A study by a french group found that teenage haevy drinkers can lose more than marks on a test. Brain scans of alcohol-dependant individuals aged from 30-50 years showed a definitive loss of white matter. What is important here is this, the age at which these individuals started drinking is related to decreased grey matter volume in the cerebellum, brainstem and frontal region.

Reference: Chanraud et al. 2006. Brain Morphometry and Cognitive Performance in Detoxified
Alcohol-Dependents with Preserved Psychosocial Functioning. Neuropsychopharmacology, October issue, p. 1-10.

Image by Ottmar Liebert taken from Flickr under creative commons (CC) license

Wednesday, November 29, 2006

Teaching tip #2: Power point and laser pointers, a No-No?

Do you have a laser pointer? I do! Do you use it with your power-point slides? I used to! Not anymore! There is a very simple reason why I used to ...and do not anymore. The laser pointer is actually a good thing for the teacher...because we have in our mind a picture of what the students ARE SUPPOSED TO we circle and underline with the laser pointer. This is not useful because the students ARE OFTEN WRITING AS WE TALK....the never see the laser pointer because it does NOT stay on the slide. Thankfully, there is a remedy to this. Power-Point has a feature that permits HIGHLIGHTING, DOODLING, CIRCLING things on your slide...and it stays there!

Here's how to use it: when you are on your slide, just right click and a box will appear! Select from the options and VOILĂ€...just look at the picture that accompanies this blog and you will quickly understand how to use this simple tool. Use it on your next lecture and you probably will, just like me, get addicted to it!


Teaching tip #1: Discourage free-riding!

Free-riding is common when students work in teams. Make sure you meet every student from the team separately and ask what their contribution is. Beware of blank stares!

The best science Podcasts

Podcasts are a very efficient, and fun, way to learn about the last developments in the world of science. I strongly promote this medium to my students and, one in a while, I quiz them on specific segments. Furthermore, these science podcasts are all produced by highly reputable journals and news organizations. Pure and FREE listening pleasure...Enjoy!

There are more and more many things to learn and so little time!

Tuesday, November 28, 2006

The power of low tech teaching!

This blog is about Cyber teaching...or is it? I just want to share an experience. I teach at med school where all the students have their own tablet PC. All of their notes are in Power-Point format and that is great...HOWEVER....I decided yesterday to do something different. On one side of the class I used the projector, with the Power-Point slides. On the other side, I had a white board. Instead of going through the slides and babbling about whatever they had on them, I thought it would be a good idea to slow down the rythm. I started to draw, explaining as my "work of art" was being created. I was, as I was before I made extensive use of Power-Point, telling a story. After class, students came to me to tell me how they appreciated how I took the time to explain instead of going through a bunch of slides.

Teaching is about creating a contact with the students. Teaching is about reaching other people through knowledge transfer. Anyone can look at Power-Point slides and study them. A professor who teaches only with electronic media is not doing a better job than a professor who reads transparents. Teaching is NOT about reading something students can read by themselves.

The use of cyber teaching is a GREAT idea, I am totally with it and I use it quite extensively. I think it is important to remember that a Power-Point slide is just a high-tech transparent. Teaching is an art, not just a technique!!!

The problem with many academics...

You know what you teach about...but is it blurry for your students?
Students need a link. They need something to cling on. Students need applications. Students need demonstrations. The problem with many academics is this: they are the only ones interested in their subjects. They teach about something that is very specialized and not very relevant to the student experience.

I am not saying that very specialized subjects should not be taught. They should be but in a general context. A very specialized subject usually comes from a specific context. Applications and examples are sometimes difficult to find especially with very specialized content. It is, nonetheless, an important part of teaching. I think that if researchers have the imagination to conceptualize complex ideas...they should have the imagination to find examples that students can understand and rely to.

How selfish can you be?

I teach an undergraduate class where many of the students want to go to med school. There is a lot of competition...

I take pride to answer my email as quickly as possible and for every answer I provide, I send the question(s) and answer(s) to ALL my students. One student is not pleased by that...he would rather like that I answer his questions only to himself....I bet he reads all the answers of the other students questions...just to get an edge....arghhhh!

Monday, November 27, 2006

Intelligent Design for Dummies...really!

UK is under attack, creationism is striking! A group know as Truth in Science decided to promote these non-objective beliefs through distribution of DVD's and booklets. This group, with their spokesman Dr Richards Buggs financed a £20,000 creationism teaching program, targeting pupils in state and private schools.

According to the book of Genesis, life was created by God 6,000 years ago! 6,000!!! How can intelligent people, like Dr. Buggs who has a Ph.D. in plant science and an expert on polyploidy promote totally unscientific ideas. People might not agree about everything Darwin said, he made mistakes, but the science is there. DNA has been sequenced, microfossils have been carbon dated and they are way older that 6,000 years! I just do not you? Is there something I am missing here?


Saturday, November 25, 2006

Toxins and perfumes: the death of dissidents and spies

The ex-spy is dead. Alexander Litvinenko died like a spy, almost like in a movie. An obscure poison got the best of him...but how toxic are poisons? Paracelsus once said: "everything is poison, it depends on the dosage"...some toxins are very powerful some less. Lets list a few toxins and compare them...just to have an idea.

  • Botulism toxin is an exotoxin produced by Clostridium botulinum. This toxin is the MOST toxic toxin known to man. Its lethal dose is known to be around 200 pg/kg (so a human could be killed by as little as 10 ng of this toxin)...used as Botox
  • Tetanospasmin is another highly lethal bacterial toxin. It is produced by Clostridium tetani bacteria. Ten times less powerful than botulinum toxin, it would take a dosage of 100 ng to kill a human.
  • Strychnine is a plant derived toxin (from Strychnos nux-vomica tree) and is considered very toxic although it would take around 50 mg to kill a human. A problem with this toxin, the taste can be detected at very low doses
  • Ricin is a toxin extracted from castor beans (Ricinus communis). Its lethal dose is 0.2mg. This toxin was used to kill Georgi Markov in London in 1978. Markov was shot in the leg and the bullet was coated with ricin.
  • Sarin is a very toxic substance also known as O-Isopropyl methylphosphonofluoridate. This poison was used in a japanese subway in Tokyo in 1995 by a religious sect; Aum. The lethal dosage for sarin is around 0.5 mg (humans).
  • Cyanide is a well known poison. There are various forms of this toxin so the dosage varies. Was widely used in suicides by Nazi. As a comparison, Sarin is know to be around 500 times more toxic than cyanide derivatives
  • Dioxin is also a well known toxin. It was found in agent orange used as a defoliant durins the Vietnam war. Recently Viktor Yushchenko was poisoned with dioxin. The lethal dose of dioxin is around 1 mg.
  • Polonium killed the ex-spy Alexander Litvinenko. Although that, weight for weight, this radioactive element is more toxic than cyanide it will take micrograms to milligrams to kill a human.

Friday, November 24, 2006

CDC and censorship...does it have to come to this?

Amazing... I heard a rumor the other day. Someone said on the radio that the Center for Disease Control was censoring its own information. Information trusted around the world for its accuracy and, I thought, impartial and objective educative mission. Was I I dreaming? It seems that the CDC is now censoring information on condom use...see for yourself on that site! What the hell are they thinking...Bush's hands are everywhere it seems...the rumor seems to be true...conservative values are killing people...I just cannot get over this!

Visit that site, tell me about it!

Cyborg 2.0 (My tribute to Kevin Warwick)

Intelligent Design exists! Kevin Warwick, from University of Reading, the self-called Cyborg 2.0, proves it. In an article published in 2005 in International Journal of Adaptative Control and Signal Processing, Warwick and colleagues designed an implant that can be well tolerated by the body (96 days) and that can establish a by-directional link between the human nervous system and a computer. In their article, they demonstrate the many uses of this implant. For images, they are copyrighted, see Dr. Warwick's site (

Reference: Gasson et al. 2005. Invasive neural prosthesis for neural signal detection and nerve stimulation. Int. J. Adapt. Control Signal Process. 19: 365-375

An article on Warwick published in Wired Magazine HERE
and HERE

Zap my brain dude! (the making of Homo sapiens 2.0)

Hey, brain improvement freaks...interesting news, very interesting news! Electric shocks are no longer used for therapy alone...electrical jolts can now be given to people interested in improving their brain performance. At the university of Luebeck, Jan Born recruited medical students and found that minute electrical shocks could increase the deepness of sleep, as monitored through EEG. It seems, according to Born, that a memory boost was the result of these tiny jolts. How is that possible? A paper published in Nature on November 2nd 2006 might shed some light on this question.

Andrew Jackson and his colleagues at the university of Washington in Seattle demonstrated, using Macaca nemestrina monkeys, that artificial connections in the brain can be made using electronic implants. In an experiment, these authors used an implant (Neurochip) that recorded the activity in one region of the brain only to deliver an electrical current at another location. After a few days of operation, the implant was turned off but the association and synchronization between the two brain regions remained showing a potential, and artificially created, pathway. The electronic recording / stimulation was maintained during sleep, even during REM sleep when neuron firing is at its peak, because sleep has been implicated in motor memory.

In another paper, published in Nature as well (July 13, 2006), a paralysed man could, through the emission and accurate detection of brain waves, play games on a computer and read e-mails. Our brains, although very different from computer hardware, seem to be fully compatible with software. I just can not wait for the next Google/Wikipedia implant...I know for sure that I will now be able to win, at Trivial Pursuit every single time. My wife will be less happy...she's the one who always wins against me at that game...oh well, looks like I need to visit Radio-Shack!


Andrew Jackson et al. 2006. Long-term motor cortex plasticity induced by an electronic neural implant. Nature, vol 444, p. 56

Leigh R. Hochberg et al. 2006. Neuronal ensemble control of prosthetic devices by a human with tetraplegia. Nature vol 442, p. 164

Thursday, November 23, 2006

Polio....still around after all those years? YUP!

I am teaching microbiology. We are presently in our virology section...and year after year I say the same thing...poliovirus will be day! The thing is that cases have gone up in 2006 in comparison to 2005...but the good news is that the increase was felt only in endemic countries. For instance here are some interesting numbers:

  • Endemic countries 2005: 1528 cases
  • Endemic countries 2006: 1686 cases
  • Non-endemic countries 2005: 873 cases
  • Non-endemic countries 2006: 108 cases
These numbers are interesting because they seem to show that vaccination in some countries is actually working. Some of the non-endemic countries were endemic decades ago. OK, vaccination works, but why is it that this disease is still around? I do not have the answer to that but the World Health Organization (WHO) with a new leader in Dr. Margaret Chan might, this time, succeed. In her speech she mentionned:" We will complete polio eradication".

I hope this terribly delibitating disease will be wiped off the surface of our planet....soon!

From space....

Doing a bit of research on Intelligent Design...I stumbled on this site! How come I never though of this? After all...don't we have SETI?

See for yourself HERE !

Epigenetics and missing parts: The making of the Homo sapiens machine

Who would have thought? We are not exactly what our genes say we are...

As you know, we have tow sets of chromosomes. One of paternal origin and the other, well, from our mom! Genetic traits are transmitted from generation to generation and this long nose of yours is probably found in some of your family members. It has been found that we are more than that. In fact, tiny modifications on your DNA control the way the genes are turned on...or off! In plants, environmental stress on a generation can modify the expression of some genes in the next. How can stress affect the way the next generation behaves. Is that possible in humans? Some think it is. Stress, nutrition and possibly other factors can influence the way our DNA is expressed. Thses factors modify DNA structure by adding methyl groups (-CH3) here and there. These modifications, leave the sequence intact and can be passed to the next generation. These modifications can either activate or inhibit gene expression.

Ragarding stress, an important and interesting experiment is taking place. Dr. Rachel Yehuda, a specialist of posttraumatic stress disorder, is following the offspring of women working at or at close proximity of the WTC towers. In one of their studies, they found that head circumference was decreased in infants born from these mothers. In the years to come, the children will be followed for neurological development. Some researchers have found that malnutrition of an expecting mother can increase her offsprings chances to develop diabetes stroke and even heart disease later in see, we are not what our genes say we are.

Furthermore, it is known that our individual DNA is different from other individual. We might share 99.9% of the DNA sequences, there are many spots where these sequences are different. These differences help pharmaceutical companies to understand why some people are fast or slow drug metabolizers. It helps police to identify criminals that leave biological tracks and help body identification when disaster strikes. It now seems that there are more differences in our DNA than previously thought. In the latest Nature issue (23 november 2006), researchers demonstrated that genetic variation within individuals is more complex than previously assessed. In some cases, whole sequences were deleted.

Friday, November 17, 2006

Are we the ORFans of the universe?

In a recent posting, the Christian Post stated: "Intelligent Design Defended by Unsolved Genetic Puzzle". This article appeared online on Nov. 17, 2006 at 2:45 PM.

In a recent conference, Dr. Paul A. Nelson (Biola University) stated that "I want to remind you that you don't need a theory of design to know that is design". In an attempt to discredit Darwin's theory of evolution by common descent, Dr. Nelson focused on ORFans, genes that seem to have no ancestral descent. In a nutshell, ORF (Open Reading Frames) are segments of DNA that code for proteins. As these genes change in evolution, a track is left. Following these tracks, through the use of computers and bioinformatics, can lead to a common ancestor. ORFans are genes that have no known common ancestor....but also, on a more technical point of view, ORFans are annotated open reading frames with no homologs in CURRENT databases. This could change with more research.

Dr. Nelson argues that humans rationality can detect intelligence without further evidence. He gave the mycoplasma example, a very simple organism that has 33% of its genes as ORFans. If I understand well, this points to the fact that the more ORFans an organism has, the higher the evidence that it originated from intelligent design.

Let me point you in another direction. Bacteriophages are bacterial viruses. These tiny creatures have the ability to inject their DNA in bacterial cells. According to Rocha and Danchin (2002) bacteriophages could be responsible for introducing A+T rich sequences into bacterial genomes (ORFans are known to be A+T rich sequences). So far, bacteriophage diversity has been poorly characterized....therefore homologs are difficult to find!

Dr. Nelson, please acknowledge that having no KNOWN homologs does NOT point in the direction of Intelligent Desing. Lets be objective here!


E.P.C. Rocha and A. Danchin. 2002. Base composition bias might result from competition for metabolic resources. Trends in Genetics, 18:291-294.

Thursday, November 16, 2006

Intelligent design has to go!

I believe the world around us is mysterious, amazing, unbelievable, wonderful...but why do people have to put "GOD" in everything? Nature evolved for IT'S OWN SAKE, not to make our lives happier! Nature, to our eyes, can be cruel and selfish...Evolution is selfish! Evolution is there to promote the survival of species...for their OWN good! No higher force required!