Tag Archives: DNA

Elements necessary for humans

Leave a reply

At present there are 118 elements listed in the periodic table. Some of these elements are commonly found on the earth in the form of ores. Some are radioactive and have very short half lives. Many such elements have been synthesized in the laboratory and live for a very short time.

Human body like other things existing is made of compounds which are made from the elements. Out of these 118 only some elements are connected with the human body.

Although elements as such don’t make up the body it is the combined form that is molecules constitute the human body. But elemental composition is as follows by mass.

Oxygen: 65%

Carbon: 18%

Hydrogen: 10%

Nitrogen: 3%

Other elements: 4%

Other elements include Calcium, Potassium, Phosphorus, Sulphur, Sodium, Chlorine, Magnesium, Boron, Chromium, Cobalt, Copper,  Fluorine, Iodine, Iron, Manganese, Molybdenum, Selenium, Silicon, Tin, Vanadium and Zinc.

Although these elements are used in very minor amount, they are crucial to some body processes.

Elements can be divided into different groups according to the functions they perform.

Building Blocks

The main building blocks of the body are proteins which are synthesized from amino acids. For these elements used are Hydrogen, Carbon, Nitrogen, Oxygen, Phosphorus and Sulphur. DNA also contains these elements except Sulphur. DNA is the genetic code.

Enzymes

Enzymes are chemicals which are catalysts for carrying out chemical reactions like breakdown of sugars and other macro molecules. Such enzymes use some elements like Magnesium, Manganese, Copper, Zinc, Selenium and Molybdenum. Enzymes play role in respiration, digestion, metabolism and immune system.

Nerves and Control

Brain sends messages to different parts of the body and this is a two way communication. Electrical signals are carried through electrolytic solutions like brines. Sodium, Potassium and Calcium ions this play the role of transmitting the signals. Similarly Chloride ions regulate the water in and out of cells. Iodine is used to make hormones which regulate metabolism.

Bones and Teeth

Bones make the template on which our body is hoisted. Strong bones and teeth are essential for the healthy body.  Bones and Teeth are made of Calcium and phosphate. Phosphate contains Phosphorus and Oxygen. Manganese element makes more stronger and resistance to breaking.

Blood

Blood is the lifeline of the body. Blood carries oxygen to the cells and removes the carbon-dioxide gas which is the byproduct of combustion reaction. Oxygen is carried by blood due to the presence of iron which binds the Oxygen. Other elements which are constituents of blood are Carbon, Oxygen, Iron and Cobalt. Cobalt is essential to make red blood cells.

Respiration and Energy

Respiration is inhalation of Oxygen. Adinosine Triphosphate (ATP) is formed during respiration which is the compound used by body as energy. Main elements involved here are Carbon, Nitrogen, Phosphorus and Oxygen.

Source: c&en magazine of American Chemical Society (ACS)

DNA Decoding Sheds Light on Neanderthal Life

Leave a reply

DNA decoding is a powerful technique. It is a molecular level investigation tool about the life. It has helped the life scientists to say with confidence that at the molecular level, all life is identical to 99.9%. The remaining 0.1 % is all which is responsible for the vivid diversity of life.

According to one report, Neanderthals, our distant cousins, used natural drugs to alleviate the pain and diseases. 50000 years ago, they were depending on the natural cures. The ancient fossil of jaw had been studied genetically and it has been found that genetic material collected from the plaque of teeth belonged to oral bacteria and leaf pieces of  medicinal compounds.

They have found methanobrevibactor which indicates abscess. These bacteria damage the teeth and cause severe pain.

Also DNA material belonging to the bacteria Enterocytozoon bieneusi. These are intestinal bacteria and cause diarrhoea.

Populus trichocarpa Popolar tree pieces which contain salicylic acid which is an ingredient of aspirin the pain killer. It would have been effective against the pain in abscess.

Penicillium rubens are food fungus and source of medical penicillin. This natural antibiotic would have been effective against gut parasites.

Most of the material has been published in the Times of India newspaper.

Budgies in our homes

Leave a reply

Many a times we thought of keeping pets at home. Our preference was always on keeping a dog but it is not practical with our present circumstances. Being two old persons, it is very difficult. It has to be regularly taken out for walks not doing which will be an injustice to the animal. More difficult is the situation when both persons have to go out for somedays. Where to keep it then? We had this experience in the past when we had a beautiful Labrador as a pet. Unfortunately, it’s association with us was brief and it’s life was cut short. This incident also left a kind of fear and apprehension to keep the pet dog again.

So our choice fell on birds. We brought home a pair of budgies in a cage. Difference between birds and dogs as pets is that a dog forms a strong bond and share our moments of happiness and sorrow. Dog will never desert us and miss us when we are away and wait for the members of the family who have gone out and will be returning. Birds on the other hand, especially budgies, don’t form such attachment. Should they happen to fly out by accident from the cage, you cannot expect them to come back. They can be left provided they have enough food and water in the cage.

All day we cared for them. Taking the cage out in the summer evenings and keeping them inside in the cool. They were given the food purchased from the pet shop. They also like to nibble at the leaves of certain plants and trees like coriander and silver oak.

During the summer months one day their cage was kept hanging out. It was cleaned. Water and containers were cleaned. It so happened that one of the doors was left opened inadvertently. The male budgie came out. When it was found out, it was sitting on the top of cage and our effort to catch it scared it and it flew away and sat on a tree. We located it perched on a nearby tree but were helpless. We lost its track. Since these birds cannot endure the long flights, it must have been killed by the hawks which lurk there on these trees.

The female was left alone. Whole day it was making calls and seemed desperately missing its partner. We were also anguished and were at a loss as to what should be done. We considered many options like giving it to pet shop owner. Other was to find another male which should be compatible with it. After few days, we found one in one shop and brought it home. In the beginning, female would not allow it near and peck it angrily. But to our satisfaction they became friends and played and twittered together.

After somedays, the female began laying eggs. But since these were on the cage bottom sieve, these were broken by the female. After consulting some people having this experience, we brought one fired round clay pot with open top and one big hole carved on one side. This was fixed in the top of the cage.

Female began to survey it and inspect it. After few days both were going in, sitting and coming out. An egg was laid followed by two three more but for days on nothing was coming out of the. Female began sitting for long periods on the them. At last a day before Diwali festival, one of the eggs hatched and a very clumsy mass of flesh was there. That it was alive could be judged only from its shivering. The one after another three were there. There were still three more eggs remaining.

We were thinking how they will be fed but our fears were unfounded. The male who was now a father would eat the seeds and crushed them inside its gullet and then pass the liquified food to female who further churned it finer and fed it to the newborns. From morning till sunset it went on. The kids began growing and still very clumsy with no eyes and no plumage. I was surprised how the parents kept track of feeding each one. Six chicks jostling in a small space. But it is hard wired in their DNA and there is no need to learn. Meanwhile the other eggs hatched after a few days spacing. After fifteen days the eldest one had small plumage and eyes began opening. Others followed suit. Plumage became richer and one by one beginning with eldest began to take shape of the grown ups. We transferred them all to a bigger cage.

In addition to the normal shop bought food, we also fed them fresh green rice which I brought everyday from the fields nearby our home since the like the seed with cover intact. We also tried the wheat soaked overnight in hot water. They become habituated to it after few days of hesitancy. But here also they removed the outer coating to take only the core material.

When six chicks are growing in small space, the waste material accumulated inside the nest. But many a times, female frantically dived in and brought out the waste material and threw it away to keep the nest as clean as possible.

Another feature was that female never allowed the male to feed chick directly. He will only watch from the top of nest or gathering another round of seeds while female fed the chicks.

They began straining their necks out. Eldest one started fluttering the feathers. Then one day, when we removed the cover from the cage, we were surprised to find the first one sitting at the cage floor. It is very beautiful and have blue and green color. It began nibbling the seeds but would expect the easy way of being fed by its mother. But she was stern with it and only once in a while gave it food. But Another another problem cropped. The father began pecking it harshly and was scaring it constantly. We have to transfer it adjacent partition although with heavy heart. It fretted there and became very aggressive.

In the evening, we went out and returned after dark. I was surprised to find that the small one has gone back to the nest because how it flew there is hard to imagine. Another day second one only came down and after hopping here and there and eating the seed went back in the night.

It began to be cool weather because of November month. We have to leave the place for few days. Luckily our daughter who lives nearby was ready to help. We told her the procedures and eating times and food. She is managing them now. Only one which hatched in the last, remains in the nest. All others have left the nest to become independent.

Two lives have become eight now. It is the way of nature. Below are some pictures

Kallianwala Khooh: Another Example of British Brutality

Leave a reply

It is said that sun never set on the British empire once upon a time. They colonised most of the world and plundered all kind of wealth by making the innocent inhabitants their slaves. India was subjected to this treatment for two centuries. In the process to subjugate those who tried to oppose, they perpetrated heinous crimes.
One such famous incidence in firing on the unarmed and peaceful thousands of people in the Jallianwala Bagh in Amritsar Punjab. Another instance of their brutality came to light in the same district at Ajnala. There was a well called Kallianwala Khoo (well) once upon a time. This well was excavation by volunteers. The digging began on 28th of February 2014 and within 3 days, skulls, bones, some coins of East India company and jaws were excavated.
It’s believed that it was here, in this khoo or well, that the bodies of 282 Indian soldiers who rebelled against the British during the 1857.
Covered in the freshly dug earth were skeletal remains — skulls, bones — coins and pieces of jewellery.
Amritsar based historian Mr.Surinder Kochhar who led the excavation did a lot of research before undertaking this task.
By March 2, the excavators — mostly volunteers — had dug about 23 feet and claimed to have exhumed 90 skulls, 170 “intact jaws”, more than 5,000 teeth, 70 one-rupee gold coins belonging to The East India Company, gold beads, three gold amulets, six finger rings, four karas and two medals dated 1835, before they declared the digging complete.

20140629-202900.jpg

Standing a few feet away from the well, Amritsar-based historian Surinder Kochhar, who led the group of amateur excavators, says the decision to excavate the well was based on historical research. He had based his claims on then Amritsar Deputy Commissioner Frederick Cooper’s book, “The Crisis in the Punjab” , published in 1858, which vividly narrates the incident and on the Amritsar District Gazetteers from 1883 to 1947, all four editions of which mentioned the Kallianwala Khoo killings.
According to popular history, the 282 soldiers buried in the Ajnala well were part of a platoon of 500 soldiers of the 26th Native Infantry who had revolted at the Mian Mir Cantonment in Lahore during the 1857 uprising and had swum across Ravi to reach Ajnala town in Amritsar. Around 218 of their comrades were killed by the British at Dadian Sofian village near Ajnala. Of the remaining 282, many were captured and put in a cage-like room where several died of asphyxiation, while the rest were shot dead. Their bodies were then thrown into the well.
If DNA testing is conducted, it could be another evidence,” he says.
Dr Sukhdev Singh Sohal, professor of history at the Guru Nanak Dev University in Amritsar, says there is no unanimous view on how the well got its name. The popular view, he says, is that Kallianwala khoo means the ‘well of the blacks’, referring to “dark-skinned Indians”.
The villagers want a memorial and a museum in Ajnala in memory of the soldiers. There have also been proposals for DNA- and carbon-dating tests on the exhumed remains. The government has decided to set up a committee of historians to examine these demands.
“We are getting suggestions from various quarters, including from INTACH, saying that the skeletons should be studied to ascertain how the soldiers could have been assassinated. Were they beheaded, shot dead or killed using some other means?” says Randhawa. Back at the site, Kochhar says, “A lot of research has gone into this. I didn’t dream of the well.” That the reference was to a seer’s dream that triggered a failed gold rush at Unnao in UP, wasn’t lost on anyone.
FROM COOPER’S BOOK
“Ten by ten the sepoys were called forth. Their names having been taken down in succession, they were pinioned, linked together, and marched to execution; a firing party being in readiness. About 150 having been thus executed, one of the executioners swooned away (he was the oldest of the firing party), and a little respite was allowed. Then proceeding, the number had arrived at two hundred and thirty seven; when the district officer was informed that the remainder refused to come out of the bastion, where they had been imprisoned temporarily a few hours before. Expecting a rush and resistance, preparations were made against escape; but little expectation was entertained of the real and awful fate which had fallen on the remainder of the mutineers… The doors were opened, and, behold! They were nearly all dead! Unconsciously, the tragedy of Holwell’s Black Hole had been re-enacted. No cries had been heard during the night, in consequence of the hubbub, tumult and shouting of the crowds of the horsemen, police, tehsil guards and excited villagers.
Forty five bodies, dead from fright, exhaustion, fatigue, heat and partial suffocation, were dragged into light, and consigned, in common with all other bodies, into one common pit, by the hands of village sweepers…The execution at Ujnalla (read Ajnala) commenced at day break, and the stern spectacle was over in a few hours. Thus, within forty-eight hours from the date of the crime, there fell by law nearly 500 men.”
— Extracted from The Crisis in the Punjab (1858)

As you might have seen in many documentaries on the Discovery Channel, the extraction of the remains of the bodies requires great patience, delicacy and is time consuming. This is because with time the bodies become very fragile and prone to disintegration. Here, the work was done by volunteers who had no knowledge of such delicate processes. They in their enthusiasm did the work in 3 days and it might have caused deterioration to the quality of the remains.
Now the mortal remains are in the possession of the Punjab Director of Cultural Affairs. A team of two professors from the department of Anthropology from Panjab University for working out the biological profiles and DNA profiles to identify the soldiers. Since there are no records of the names of the soldiers, British government has bee requested to provide the details of the soldiers who were killed in the massacre.

20140629-203236.jpg

Corn: Propeller of lives

Leave a reply

Corn along with rice and maize are the basic grains used all over the world. They evolved in different parts of the world in different climates and conditions. Wheat for example is said to have originated in Middle East. Rice requires plenty of water for cultivation and thus grown where rains are heavy or other sources of water are easily available. Here we are talking about the evolution of corn.

Evolution of the parent wild varieties have taken place man’s patient, persistent by a method of selective breeding over the centuries.  The history of modern-day maize begins at the dawn of human agriculture, about 10,000 years ago. Ancient farmers in what is now Mexico took the first steps in domesticating maize when they simply chose which kernels (seeds) to plant.

These farmers noticed that not all plants were the same. Some plants may have grown larger than others, or maybe some kernels tasted better or were easier to grind. The farmers saved kernels from plants with desirable characteristics and planted them for the next season’s harvest. This process is known as selective breeding or artificial selection. Maize cobs became larger over time, with more rows of kernels, eventually taking on the form of modern maize.

Evolution is said to be gradual and slow. But in the case of corn, it evolution occurred in a burst of fairly small time. After a long search, the scientists became sure about the ancestor of maize. Its name is Teosinte. Plants are totally dissimilar but the DNA is very similar and two can be easily crossed to produce modified intermediate varieties. Samples bear an unmistakable resemblance to modern maize.

Following shows a collection of sizes and shapes of cobs beginning from the earliest.

CornProgression
Second picture shows the comparison of Maize and Teosinte plant and cobs from which Corn has evolved over thousands of year. The hybrid corn resulting from crossing the two is also shown at bottom.

MaizeTeosinteCross

Chemistry of Tanning

2 Replies

People in Asia and Africa where plenty of sunshine is available and weather is hot have a auburn or dark skin. This is because of production of melanin in the skin and making it look brown or dark. In Europe, particularly the Northern parts, there is hardly any Sun to be seen for most of period of the year. Due to the shortage of melanin, the color of the skin is white or what is called fair.

Most people are not satisfied with whatever have God given to them. For example, the people in India want to look fair like Europeans and vice versa. Europeans come to India and sprawl themselves on the sunny beaches in the hope of getting the tanned skin.

Tan is caused by the action of UV rays on the cells of the body. The UV rays have higher energy than the visible spectrum light. UV spectrum is further subdivided into three ranges namely UVA, UVB & UVC with decreasing wavelengths and increasing energies from UVA to UVC. UVC are so energetic that they react with the matter in atmosphere and never reach the Earth. UVA & B both break the bonds. UVB stimulates the production of melanin by burning the skin and destroying DNA and gives the tan to the skin.

Interaction of UVB with skin produces vitamin D3 which is required to transport calcium to the bones. Additionally UV reduces the stress and eases the tension. There is scientific evidence that sunshine has a mood lifting effect and people in the places where the Sun is not seen for months show the symptoms of depression. Thus UV which is always seen in the negative terms has good side also.

But it is not healthy to expose your body directly to the UV rays. Instead sunscreens are beneficial and make the tanning in the Sun. How much time is safe for tanning is calculated by Sun Protection Factor (SPF) ratings on sunscreens. The SPF number is a “multiplier” and formula to calculate the safe time is = Minutes to burn without sunscreen x SPF number

For example, if a sunscreen has a SPF value of 20 and it takes 12 minutes for your skin to burn without sunscreen, then sunscreen will protect you for 240 minutes (12 min. x  20 SPF = 240 min.). Doctors recommend a water-resistant sunscreen rated 15 SPF or higher with UVA and UVB protection, generally labeled “broad spectrum.”

Maybe the best tan is sunless. “Tan in a Can” products use materials that generate a tan without UV exposure. Creams, gels, lotions, and sprays contain dihydroxyacetone (DHA), a sugar that colors the outer skin cells. Unfortunately, this nice tan usually lasts only one week because you constantly shed dead cells.

 

Graphene: Size Zero Allotrope

Leave a reply

Carbon is the atom on which the life on the earth is based. Though it is not a complicated element having only 6 atomic number, it ability to form compounds with hydrogen, oxygen, sulfur and host of other atoms and its ability for catenation makes it the most distinguished element for us. We owe our existence to it. Most of the macromolecules which are bodies are composed of contain carbon, hydrogen and oxygen.

This simple element show another very surprising properties. One of them is the allotropy. Two allotrope are two different arrangements in which an element can exist. Till 2004, two allotropes of carbon, diamond and graphite were recognized. A simple change in the way atoms are arranged geometrically can drastically alter their properties.

Diamond is network of tetrahedrons in which each carbon is joined with 4 other carbon atoms and so on. This forms a network which is the hardest material in the world. It sparkles in the light as the light is refracted at so many faces and unable to escape.

Graphite on the other hand is the form in which carbon atoms form honeycomb structures of hexagons joined to each other in the layers. The attraction between layers is not much and layers can slip over one another giving it a lubrication ability. Since there are are free electrons between the layers on each carbon, they form a tunnel in which electrons can move. Thus graphite also conducts electricity.

Now comes the Graphene. If you peel each layer, you have a two dimensional material which is thinnest material in the world. It is only 1 carbon atom thick and but at the same time it is the strongest material in the world, 100 times stronger than the steel.

Only limitation presently is its manufacture on commercial level in the purest form because contamination of even in single alien atom can spoil all the properties.

So many uses are already envisaged for this material. Since it conducts electricity better than any other material and unbreakable and very thin, future cellphones and other electronic touch screen gadgets shall be made from this. These shall be very thin, would not break on falling and could be folded to suit the pockets.

Another use shall be in the bionic devices because it is flexible and highly resistant to the corrosion caused by electrolytes present in the cells of human beings. These devices can be inserted at any place for many years without worrying for replacement.

At present scientists are trying to explore methods of making it on commercial scale. May be some genius like Kary Mullis device something like Polymerase chain reaction (PCR)  to multiply it million folds from a single copy. Nothing is impossible.