About 4 million years ago, humans had split from apes. At this time, Chimpanzees had to go through some tough times. They were infected with a virus. Scientists discovered this when they found traces of this virus in the DNA of Chimps. This meant that this virus, called PtERV1, infected the Chimp population. Interestingly, the traces of the virus were not found in human genome.
Emerman and his team had an explanation. The humans immune to PtERV1 while Chimps had tough time fighting it. The team of researchers identified TRIM5 as the factor that helped humans protect us from the virus. Removing this protein from the cells made them vulnerable to PtVER1, which were reconstructed from Chimpanzees DNA.
Curiously, these cells were found to be less susceptible to HIV. It seems that in the process of developing resistance to one virus, the immune system of our ancestors had us vulnerable to another deadly virus, the HIV.
What made HIV infect Man?
Journals Online
Science knows no boundaries!
Here are a few websites that offer free access to some journals on the world wide web!!!
Current Science
BioMedCentral
Directory of Open Access Journals
Free Medical Journals
High Wire Press
PhysNet - Physics related free-access journals
If you know any other such useful websites, please do add those links as comments...
Making alcohol the nano way!
Ethanol (the alcohol) is one of the most talked about alternative for the fossil fuels. For thousands of years, alcohol has been produced from yeast. This way of using biological cells to make alcohol is not generally considered non-viable. Thats because we spend more energy than what we get.
Carbon Nano Tubes (CNTs) are tiny tubes made only of carbon atoms. These are too tiny that the properties of chemicals are often altered when they are in these tubes.
CNTs were found to catalyze the production of ethanol from carbon monoxide and hydrogen. CNTs act either as catalysts or catalyst additives.
In China, its been proven that CNTs loaded with Rhodium nanoparticles as reactors to convert the gas mixture of CO and Hydrogen into ethanol. Dr. Xinhe Bao and his team of researchers in Nano and Interfacial Catalysis Group in Chinese Academy of Sciences observed that the redox properties of metal nanoparticles are modified when they are inside CNTs.
Syngas (a mixture of CO and H2 in the ratio of 1:2) when introduced into the CNT loaded with Rhodium- Manganese catalyst, gets converted to acetaldehyde, acetic acid and ethanol very quickly. The Chinese scientists suggest that this is due to
1) a host guest interaction between CNT and Rhodium - Manganese nano particles.
2) stringent size restriction of metal particles inside CNT.
3) high affinity of H2 to the inner surfaces of CNT.
The DNA message
You probably know that DNA carries the most invaluable information, without which the mere existence of life is impossible. Have you ever wondered whether DNA can be used to store more than just the genetic information? If you had thought of it before, you are not alone(!!!!!!).
A group of Japanese Molecular Biologists in Institute for Advanced Biosciences at Keio University decided to (nearly) immortalize Albert Einstein's magical formula E=mc^2 in the DNA of a bacterium.
DNA is a thread like molecule made of 4 different compounds (represented as A, G, C and T) as building blocks. The sequence of these 4 compounds in the DNA holds the genetic information. The Japanese scientists attempted to translate the formula (along with the year of its discovery, "1905") into binary code. This code was then translated into a language that has A, G, C and T as its 4 alphabets. For example, the binary code '0000' was translated into 'AA' and '0001' was indicated as 'CA'. Once the formula was translated into DNA's language (A,G, C and T), the new sequence obtained was inserted into a bacterial DNA and stored for eternity.
The objective here, was probably to preserve 'the most important formula of 21st century'. Since the genetic information had survived for over 3.5 billion years, DNA was the obvious choice. With the ability to survive in extremely hostile environmental conditions, the harmless soil bacterium Bacillus subtilis was a suitable candidate as the carrier of the "DNA-time capsule".
I hope that these efforts prove successful and Einstein's legacy (E=mc^2) lives on long after the demise of human kind on this planet.
Hmmmm....... I wonder what role the seemingly harmless equation E=mc^2 will play in the extinction of human population!
Conotoxins
The active components of the cone snail venom are a group of neurotoxins called conotoxins. These are usually 12 to 30 aminoacid residues long. The peptides are highly constrained due to high density of disulphide bonds.
Although conserved structures are present in these peptides there are also subtle differences. These differences are responsible for the high toxicity and high specificity. These differences also ensure that each species has a unique subset of toxins. It has also been found that sometimes, the toxins differ even among individuals of the same species.
The conotoxins present in the fish eating cone snails are more effective against humans than those present in the mollusk eating snails.
The cone snail venom causes paralysis. The paralytic conotoxins belong to three main classes: alpha, mu and omega conotoxins. There are also others ... delta and kappa conotoxins.
You will find a list of conotoxins here.