MARINE ARCHAEOLOGICAL EXPLORATIONS IN TAMIL NADU COAST

Ancient ports of TamilNadu coast have played a dominant role in the transoceanic trade since very early times. It has more than 800 KM coastline with several major and minor ports along the coast. The earliest literature of TamilnNadu popularly known as Sangam literature datable between the 3rd Century BC and 3rd Century AD mentions about the maritime trade of Tamil Nadu with countries like South East Asia, Ceylone, Malaya, Roman countries and China. The important ports mentioned are Arikamedu, Kaveripoompatinam, Korkai,Nagapattinam, etc. The foreign accounts of Pliny, Periplus, Itsing and Fahien, have mentioned about the ports of TamilNadu and the items of trade. Some of the sites like Kaveripattinam, Korkai and Arikamedu have been excavated extensively and evidence on the trade and commerce with other countries have been recorded. Underwater investigations at Poompuhar and Mahabalipuram have confirmed the existence of the submerged structural remains.

Many of the ports have been mentioned in the literature as well as in the inscriptions, which needs investigations to confirm their existence. The sites covered during the recent explorations are Mahabalipuram, Punjeri, Vasavasamudram, Arikamedu, Porto-Novo,Tranquebar, Thondi, Kodikarai, Thirumalarayanpattinam, Devipattinam, Manora, Manakudi, Puttan-Thurai, Korkai, Periyapattinam, Alagankulam, Rameshwaram, Kayalpattinam and Kulasekharapattinam. The data collected at the above sites are supporting the literary evidences to prove their existence as ports.

Among all, the remains of British period jetty were observed with a memory stone explaining the war between Hyder Ali and British at Porto-Novo. At Arikamedu the Roman settlement followed by French was confirmed on the creek, which provided anchoring facility to their vessels. Naval battles between French and British resulted many shipwrecks in the vicinity. Partly disturbed Chola temple and the remains of Dutch fort were noticed in inter tidal zone of Tranquebar. Alagankulam was an important port during the early centuries of the Christian era. Roman ships laden with their wine in Amphorae jars and other goods. A mooring stone was exposed up to 75 cm with two square holes near the shore. A British period warehouse was also noticed near shore. At Kodikarai a watch tower / light house of ancient period was observed in the inter tidal zone.

The antiquity of Periapattinam suggests that it was once a flourishing port particularly in the 12th-14th century AD. A stone anchor was reported near Kappalaru between Periyapattinam village and the sea coast. Korkai, an important port for pearl fishing referred in Sangam literature and located on sea coast but presently it is located about 7 KM inland may be due to regression of the sea. An ancient site about 5 KM on the north-eastern side of Present Rameshwaram temple was explored, where 2-3 M habitational deposit along the coast was observed. Probably this could have been served as a harbour as it is located in a safer place. Kayalpattinam and Kulasekharapattinam were busy ports of horse trade during medieval period resulting large number of Muslims engaged in trade even today. Let’s hope the new Marine Archaeological Explorations would bring more knowledge on the ancient maritime works.

Raju Kannan
Research Scholar

GLOBAL WARMING

One of the most serious environmental problems today is that global warming, caused primarily by the heavy use of fossil fuels. To overcome these problems the photosynthetic microalgae are the potential candidates, for utilizing excessive amount of carbon-di-oxide. Because when cultivated these organisms are capable of fixing carbon-di-oxide to produce energy & chemical compounds upon exposure to sunlight. The derivation of energy from algal biomass is an attractive concept in that unlike fossil fuels. Since microalgae are called the scavengers of environment, because their biomass has more advantages than the fossil fuels viz… it is non explosive. Example – 150’C biodiesel compared to 64’C of petroleum diesel & also it is biodegradable, free from sulphur & it reduces the emission of carbon-mono-oxide & carbon-di-oxide. Among the microalgae, Botryococcus braunii is an unique microalgal strain having 86% of long chain hydrocarbon which is directly extractable to yield crude oil substitutes by both physical & chemical process. However, the economics of fuel production from microalgal biomass is largely dependent on a microalgal carbon-di-oxide fixation step to that required for the production of biodiesel.

V. ASHOKKUMAR

RESEARCH SCHOLAR.

SPACE MICROBES

There are creatures that were living on the Space Station before the first astronauts went inside. Astronauts found a few living on the Moon. Scientists believe they could even live on Mars. These creatures are capable of living almost anywhere—and they're living inside you right now!

It's not something out of a science fiction movie. It's bacteria and other microbes, such as viruses and fungi. The tiny microorganisms hitchhiked on the International Space Station (ISS) components when they were launched, as well as on other spacecraft. Microbes go everywhere that humans do; in fact, many of them live inside and on our bodies. Most microbes are harmless, and many are actually beneficial. However, some microbes can be harmful to people's health, or could even pose a threat to the hardware and materials of the Space Station.
While microbes are just another part of everyday life here on Earth, they can be a much bigger problem on the Space Station. The threat posed by these microbes may be even greater for astronauts in orbit than for most people here on Earth, since aspects of spaceflight are known to weaken the human immune system, which could make astronauts more vulnerable to infection. In addition, experiments performed on previous spaceflightshave shown that bacteria may grow faster in microgravity than they do on Earth. Another reason microbes are a bigger problem in space is that the people on the Space Station are living in a small, contained environment of metal and plastic for extended periods of time, exposing each other to their own bacteria in the process.

Bacteria have proved to be very resilient in living in harsh conditions in spaceflight. When Apollo 12 astronauts landed on the Moon in 1970, they found something living there—bacteria from Earth. The Streptococcus mitis bacteria were found on the Surveyor 3 probe that had been sent to the Moon 3 years earlier. While unprotected exposure to space would kill a human being very quickly, the bacteria had survived launch, space vacuum, 3 years of radiation exposure, deep-freeze at an average temperature of only 20 degrees Kelvin above absolute zero, and having no nutrients, water, or energy source. Researchers at the University of Arkansas have found that bacteria commonly found in cows' stomachs can survive in an environment like the one found on Mars.

One technique NASA uses for trying to reduce microbe-related problems is by testing astronauts for infection before they begin their spaceflight, and by trying to cut down on exposure to germs before their mission to make sure they don't catch anything prior to launch. On the Space Station, equipment is used to help purify the air and water to keep them free of contamination. Things like a special paint and maintaining low humidity also help fight microbe growth on the Space Station, but despite these high-tech solutions, astronauts still have to keep microbes off surfaces the way people on Earth do—good, old-fashioned cleaning. ISS crew members regularly wipe surfaces on the Station with cloths containing a disinfectant.

However, astronauts don't always try to get rid of the bacteria on their spacecraft, because not all of them are unwanted guests. A Space Shuttle mission scheduled for early 2003, for example, includes an experiment involving Pseudomonas bacteria, a common soil and water bacteria, which actually has been a stowaway in the water supply of previous Shuttle flights. The experiment will study the effect of microgravity on the bacteria.

M.MANJU PARKAVI

I M.Sc., INDUSTRIAL MICROBIOLOGY

CARL LINNAEUS – AN EVOLUTIONIST

Carl Linnaeus, also known as Carl von Linne or Carolus Linnaeus, is often called the Father of Taxonomy. His system for naming, ranking, and classifying organisms is still in wide use today (with many changes). His ideas on classification have influenced generations of biologists during and after his own lifetime, even those opposed to the philosophical and theological roots of his work.

Biography of Linnaeus
He was born on May 23, 1707, at Stenbrohult, in the province of Smaland in southern Sweden. His father, Nils Ingemarsson Linnaeus, was both an avid gardener and a Lutheran pastor and Carl showed a deep love of plants and a fascination with their names from a very early age. Carl disappointed his parents by showing neither aptitude nor desire for the priesthood, but his family was somewhat consoled when Linnaeus entered the University of Lund in 1727 to study medicine. A year later, he transferred to the University of Uppsala, the most prestigious university in Sweden. However, its medical facilities had been neglected and had fallen into disrepair. Most of Linaeus's time at Uppsala was spent collecting and studying plants, his true love. At the time, training in Botany was part of the medical curriculum, for every doctor had to prepare and prescribe drugs derived from medicinal plants. Despite being in hard financial straits, Linnaeus mounted a botanical and ethnographical expedition to Lapland in 1731. In 1734 he mounted another expedition to central Sweden.

Linnaeus went to the Netherlands in 1735, promptly finished his medical degree at the University of Harderwijk, and then enrolled in the University of Leiden for further studies. That same year, he published the first edition of his classification of living things, the Systema Naturae. During these years, he met or corresponded with Europe's great botanists, and continued to develop his classification scheme. Returning to Sweden in 1738, he practiced medicine (specializing in the treatment of syphilis) and lectured in Stockholm before being awarded a professorship at Uppsala in 1741. At Uppsala, he restored the University's botanical garden (arranging the plants according to his system of classification), made three more expeditions to various parts of Sweden, and inspired a generation of students. He was instrumental in arranging to have his students sent out on trade and exploration voyages to all parts of the world: nineteen of Linnaeus's students went out on these voyages of discovery. Perhaps his most famous student, Daniel Solander, was the naturalist on Captain James Cook's first round-the-world voyage, and brought back the first plant collections from Australia and the South Pacific to Europe. Anders Sparrman, another of Linnaeus's was a botanist on Cook's second voyage. Another student, Pehr Kalm, traveled in the northeastern American colonies for three years studying American plants. Yet another, Carl Peter Thunberg, was the first Western naturalist to visit Japan in over a century; he not only studied the flora of Japan, but taught Western medicine to Japanese practitioners. Still others of his students traveled to South America, Southeast Asia, Africa, and the Middle East. Many died on their travels. Linnaeus continued to revise his Systema Naturae, which grew from a slim pamphlet to a multivolume work, as his concepts were modified and as more and more plant and animal specimens were sent to him from every corner of the globe. Linnaeus was also deeply involved with ways to make the Swedish economy more self-sufficient and less dependent on foreign trade, either by acclimatizing valuable plants to grow in Sweden, or by finding native substitutes. Unfortunately, Linnaeus's attempts to grow cacao, coffee, tea, bananas, rice, and mulberries proved unsuccessful in Sweden's cold climate. His attempts to boost the economy (and to prevent the famines that still struck Sweden at the time) by finding native Swedish plants that could be used as tea, coffee, flour, and fodder were also not generally successful. He still found time to practice medicine, eventually becoming personal physician to the Swedish royal family. In 1758 he bought the manor estate of Hammarby, outside Uppsala, where he built a small museum for his extensive personal collections. In 1761 he was granted nobility, and became Carl von Linné. His later years were marked by increasing depression and pessimism. Lingering on for several years after suffering what was probably a series of mild strokes in 1774, he died in 1778.

His son, also named Carl, succeeded to his professorship at Uppsala, but never was noteworthy as a botanist. When Carl the Younger died five years later with no heirs, his mother and sisters sold the elder Linnaeus's library, manuscripts, and natural history collections to the English natural historian Sir James Edward Smith, who founded the Linnean Society of London to take care of them.

Linnaeus's Scientific Thought

Linnaeus loved nature deeply, and always retained a sense of wonder at the world of living things. His religious beliefs led him to natural theology, a school of thought dating back to Biblical times but especially flourishing around 1700: since God has created the world, it is possible to understand God's wisdom by studying His creation. As he wrote in the preface to a late edition of Systema Naturae: Creationis telluris est gloria Dei ex opere Naturae per Hominem solum - The Earth's creation is the glory of God, as seen from the works of Nature by Man alone. The study of nature would reveal the Divine Order of God's creation, and it was the naturalist's task to construct a "natural classification" that would reveal this Order in the universe.

However, Linnaeus's plant taxonomy was based solely on the number and arrangement of the reproductive organs; a plant's class was determined by its stamens (male organs), and its order by its pistils (female organs). This resulted in many groupings that seemed unnatural. For instance, Linnaeus's Class Monoecia, Order Monadelphia included plants with separate male and female "flowers" on the same plant (Monoecia) and with multiple male organs joined onto one common base (Monadelphia). This order included conifers such as pines, firs, and cypresses (the distinction between true flowers and conifer cones was not clear), but also included a few true flowering plants, such as the castor bean.

A. JAYAPRAKASH

Research Scholar

CLINICAL TRIALS: A HISTORICAL PERSPECTIVE

Although there are many definitions for clinical trials, they are generally considered to be biomedical or health-related research studies in human beings that follow a pre-defined protocol. Carefully conducted clinical trials are the safest and fastest way to find treatments that work in people, and new ways to improve health. Many clinical trials are done to see if a new drug or device is safe and effective for people to use. These clinical trials are conducted in phases. The trials at each phase have a different purpose and help scientists answer different questions.

In Phase I trials, researchers test an experimental drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects. In Phase II trials, the experimental study drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety. In Phase III trials, the experimental study drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the experimental drug or treatment to be used safely. In Phase IV trials, post marketing studies delineate additional information including the drug's risks, benefits, and optimal use.

Developing countries like India and Latin American countries are becoming ideal destinations to conduct clinical trials. There are many reasons for this. Mainly, flexibility of the government rules, availability of large pool of patients, trained physicians, low capital input and reduced study period. However, the clinical trials in developing and under developed nations are reported to misuse the patients. In several cases, patients were not informed what for they are used. And there are media reports that many patients have suffered a lot due to clinical trials and even many were died.

But using human for research is not a recent issue. Several controversial studies have contributed to the development of regulations to protect human research participants. Here I am giving very few examples for this from the web pages.

Nazi Government Research: During Second World War prisoners in concentration camps were used as subjects in Nazi experiments designed to advance the war effort. The studies involved battlefield medicine and chemical warfare experiments in which prisoners were tortured, usually to death. As a result of the methods used to conduct the experiments, the physicians involved were put on trial by the International Military Tribunal in Nuremberg, Germany from October 1945 to October 1946. Additional trials conducted by United States judges appointed by President Truman were held from December 1946 to August 1947. Fifteen of the 23 defendants were convicted and seven were executed for murder, torture and other atrocities.

Willowbrook Hepatitis Study (Mid 1950s to Early 1970s): The Willowbrook study involved infecting mentally retarded children with a Hepatitis virus to study the progression of the disease and to test vaccinations that were being developed at the time. Due to overcrowding, children were denied entrance to the Willowbrook State Mental Hospital unless parents enrolled their children into the less-crowded hepatitis ward.

Tuskegee Syphilis Study: In 1932, the Public Health Service of United States of America enrolled several hundred syphilitic black males to document the effects of the untreated disease over time. Tuskegee was chosen because approximately 40% of the male population of the town was infected with the disease. Treatment was withheld from study subjects when penicillin was accepted as the treatment for syphilis in 1943. This study was stopped in 1973 but not before many subjects became seriously ill, transmitted their disease to others or died. This study exemplifies unfair subject selection practices, denial of informed consent and excessive risk in relation to study benefits.

Milgram Study (1963): The Milgram study involved instructing subjects to administer electric shocks to a study confederate in response to poor performance. The subject believed that he/she was involved in a study about learning and memory with each shock intended to affect the learning process. The confederate pretended to be hurt by the shock - in some cases, to the point of losing consciousness; however, he/she did not really feel any shock. The study objective was to assess obedience to authority. This study resulted in significant psychological stress for some subjects including sweating, trembling, stuttering and serious seizures in three subjects. However, in a post-experimental interview, about half of the subjects expressed that they were glad to have participated in the experiment. The question of whether this study was ethical remains open to debate among scholars today.

US human radiation experiments (1944-74): Thousands of experiments took place during the cold war era in which humans were exposed to dangerous levels of radiation to test the effects of the atomic bomb, to gather safety data on the effects of the atomic bomb and to develop treatments for cancer patients. . In many cases, subjects provided informed consent prior to their participation, however this was not the case for subjects who were sick, imprisoned or otherwise vulnerable, including 54 mentally retarded children who were intentionally fed radioactive breakfast cereal. In 1993, an advisory committee to former President Clinton apologized for conducting these experiments.

M. Jayaprakashvel
Research Scholar

ARTIFICIAL LETTERS ADDED TO LIFE'S ALPHABET

Two artificial DNA "letters" that are accurately and efficiently replicated by a natural enzyme have been created by US researchers. Adding the two artificial building blocks to the four that naturally comprise DNA could allow wildly different kinds of genetic engineering, they say. Eventually, the researchers say, they may be able to add them into the genetic code of living organisms.

The diversity of life on earth evolved using genetic code made from arrangements of four genetic "bases", sometimes described as letters. They are divided into two pairs, which bond together from opposite strands of a DNA molecule to form the rungs of its characteristic double-helix shape.

The unnatural but functional new base pair is the fruit of nearly a decade of research by chemical biologist Floyd Romesberg, at the Scripps Research Institute, La Jolla, California, US. Romesberg and colleagues painstakingly created a library of nearly 200 potential new genetic bases that are slight variations on the natural ones. Unfortunately, none of them were similar enough in structure and chemistry to the real thing to be copied accurately by the polymerase enzymes that replicate DNA inside cells.

Random generation
Frustrated by the slow pace designing and synthesising potential new bases one at a time, Romesberg borrowed some tricks from drug development companies. The resulting large scale experiments generated many potential bases at random, which were then screened to see if they would be treated normally by a polymerase enzyme.

With the help of graduate student Aaron Leconte, the group synthesized and screened 3600 candidates. Two different screening approaches turned up the same pair of molecules, called dSICS and dMMO2. The molecular pair that worked surprised Romesberg. "We got it and said, 'Wow!' It would have been very difficult to have designed that pair rationally”. But the team still faced a challenge. The dSICS base paired with itself more readily than with its intended partner, so the group made minor chemical tweaks until the new compounds behaved properly.

Novel DNA
“We probably made 15 modifications,” says Romesberg, “and 14 made it worse”. Sticking a carbon atom attached to three hydrogen atoms onto the side of dSICS, changing it to d5SICS, finally solved the problem. "We now have an unnatural base pair that's efficiently replicated and doesn't need an unnatural polymerase," says Romesberg. “It's staring to behave like a real base pair”. The team is now eager to find out just what makes it work. "We still don't have a detailed understanding of how replication happens”, says Romesberg. “Now that we have an unnatural base pair, we are continuing experiments to understand it better”.

In the near future, Romesberg expects the new base pairs will be used to synthesize DNA with novel and unnatural properties. These might include highly specific primers for DNA amplification; tags for materials, such as explosives, that could be detected without risk of contamination from natural DNA; and building novel DNA-based nanomaterials.
Increased 'evolvability'

More generally, Romesberg notes that DNA and RNA are now being used for hundreds of purposes: for example, to build complex shapes, build complex nanostructures, silence disease genes, or even perform calculations. A new, unnatural, base pair could multiply and diversify these applications.

The most challenging goal, says Romesberg, will be to incorporate unnatural base pairs into the genetic code of organisms. “We want to import these into a cell, study RNA trafficking, and in the longest term, expand the genetic code and 'evolvability' of an organism”.

Journal reference: Journal of the American Chemical Society
Published on Web 25 Jan 2008. Discovery, Characterization, and Optimization of an Unnatural Base Pair for Expansion of the Genetic Alphabet
Aaron M. Leconte, Gil Tae Hwang, Shigeo Matsuda, Petr Capek,
Yoshiyuki Hari, and Floyd E. Romesberg
Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, 92037, U.S.A.

News Compiled by
Prof.N.Raaman
Centre for Advanced Studies in Botany
University of Madras, Guindy Campus
Chennai-600 025
Email:raaman55@gmail.com

NANOBES

Nanobes are tiny filamental structures first found in some rocks and sediments. Some hypothesize that they are the smallest form of life, ten times smaller than the smallest known bacteria.

Nanobes were discovered in 1996 (published in American Minerologist, vol 83., 1998) by Philipa Uwins, University of Queensland, Australia.

The smallest are just 20 nanometers in diameter. Some researchers believe them to be merely crystal growths, but a purported find of DNA in nanobe samples may prove otherwise. They are similar to the life-like structures found in ALH84001, the famous Mars meteorite from the Antarctic. Recently there has been some interest amongst bio-tech companies in commercial application of nanobes in utilization of plastics. Some researchers believe nanobe-like organisms might be implicated in a number of diseases. They might be responsible for the formation of some types of renal stones. They might even explain mysterious calcification of teeth in the human mouth, and thus actually be a useful or necessary symbiont (like Acidophilus).Although nanobacteria are sometimes called nanobes, it has not yet been confirmed that the names "nanobacteria" and "nanobes" could in fact be considered as synonyms, as both entities are controversial and are still under research.

Claims

It is a living organism (contains DNA or some analogue, and reproduces).

Has a morphology similar to Actinomycetes and Fungi.

No article or research states that Nanobes are Nanobacteria.

Nanobes are 20 nm in length which biological conventional wisdom assumes is too small to contain the basic elements for an organism to exist (DNA, plasmids, etc.), suggesting that they may reproduce via some unconventional means, like RNA instead of DNA.

The Martian meteorite ALH84001, discovered in 1996 in the Antarctic, contained similar tubular structures which some astrobiologists suggest could be proof of life at an earlier time on Mars.


GAYATHRI V

I MSc INDUSTRIAL MICROBIOLOGY