Besides food, what useful does the sea supply?

Besides food, what useful does the sea supply?
The seas are huge storehouses of valuable items. Apart from food, the waters and rocks supply many chemicals and minerals useful in medicine and industry. salt, magnesium, iodine and bromine are extracted from seawater. From shallow seas, dredging vessels haul up sand, gravel and tin and even diamonds. Oil and gas is piped up from the depths of the sea in many parts of the world.

Nowadays, special ships are being developed to suck up millions of metallic lumps from the ocean floor. These lumps, called manganese nodules will yield not only manganese but also cobalt, copper nickel and other useful substances. As the mines on land become exhausted, we will have to depend more and more on the mines of the sea.

Does the change in mother's food affect the baby?

Whatever the nursing mother eat will be secreted in her milk, but in insignificant quantities. Generally if the mother tolerates a particular food item well the baby also tolerates it well.

A normal well nourished mother secretes about 500 ml of milk daily for the first 6 months to one year and after that the quantity slowly comes down. Whereas an undernourished mother's milk is insufficient in fats and vitamins and inadequate for the baby also.

Eating fishes and vegetables contaminated with pesticides may cause problems in the baby because of their secretion in the milk. Eating spices, condiments, chocolates, onions, tomotoes may cause loose stolls in the babies.But the problems are plenty in the baby of a mother who smokes, drink alcohol and abuses the drugs. Almost all the drugs are excreted in the breastmilk and they will have their effect on the body.

For medical reasons if the mother has to take certain drugs like anticoagulants, anti-cancer drugs, antithyroid drugs, radioactive drugs, purgative etc., seh has to stop feeding her baby as long as she is on those rugs.

Does frequent switching on/off of a fluorescent lamp reduce its life?

The life of a fluorescent lamp is essentially determined by life of the cathode filament it uses. A conventional fluorescent lamp employs closely wound coil of tungsten wire as filament. Upon switching on the lamp, electric current passing through the filament will raise the temperature of the filament that in turn will generate thermions (electrons generated by a thermal process). Thermions are necessary to initiate electric-discharge through the column of the fluorescent lamp.

Frequent switching on/off the fluorescent lamp occurs through several cycles of filament heating and cooling. If the cycles of heating and cooling of the filament are too frequent this may result in tremendous loss of oxide coating (at the rate of 10-20 micro-grams/cm{+2} per cycle).

The loss of oxide coating in the cathode filament through rapid on/off (heating/cooling) operations will lead to poor performance of the filament in generating thermions to initiate the discharge process. This in turn will reduce the life of the fluorescent lamp. Life of a conventional fluorescent lamp usually rated for several thousand hours of continuous burning can be halved or made still less, just by frequent switching on/off.

Do some ships disappear with out a trace?

Most ships are used for years and years without any mishap. However, accidents can happen at sea and even the biggest ship can disappear without a trace. The ship can be overturned by a giant wave. Because of its huge size and weight, it will then sink to the bottom of the sea quickly, before anyone can send a call for help through its radio.

Ships have also disappeared during good weather, and to this day the mystery of how they were lost and where they have gone has not been solved.

Do some fish give off electric shock?

Yes. There are indeed fish, which give off electric shocks to protect themselves or to stun their prey. The torpedo ray is the fish with the biggest shock.

Do plants grow at the bottom of the sea?

Many types of algae grow on the ocean bed. But the deep ocean is too dark for plants to grow as sunlight cannot penetrate deep into the sea.

Do mermaids really exist?

It is highly unlikely that mermaids exist. What is likely is that sailor might have glimpsed a plant eating marine mammal called the manatee. The manatee floats upright while nursing its young, using its front feet to cradle its baby. From a distance, an imaginative sailor might think it is woman with a baby in her arms.

Do animals also have blood groups like humans?

In man blood group is applied to single factor. This factor is agglutinogen and is also called antigen. It is found on the surface of red blood corpuscles.

Accordingly a person with `A' antigen is designated as a person with A-group, with `B' antigen as B-group, with both A and B antigens as AB-blood group and a person without any antigens is designated as O-blood group.

In the case of animals blood group is applied to combinations of blood factors. So it is preferable to call it as blood group systems rather then blood groups. Each system has many factors, which are together called blood group factors.

Dr. J. Moustgaard, of the Royal Veterinary & Agricultural College, Copenhagen has identified in cattle ten group systems namely A,B,C,FV,J,L,M,SU, Z and R'S'. Except J and L, all the other group systems have more than one group factor. For example the group factors of the group system A are designated as A{-1}, A{-2}, D, H, Z'.

The grouping factors are particular serum proteins. Acquiring of each protein is an inherited character. So examination of blood sample from within a breed might eventually prove a very useful means of selection. It might also indicate what mating could be expected to result in infertility.

The B-group system only has greater number of grouping factors. It has nearly 27 group factors, which are called phenogroups. Some of these are unique to particular breeds.

They are particularly valuable in determining incorrectly stated parentage. In dogs serum major groups have been recognised in the USA and they are referred to as A to G.

In veterinary practice blood transfusion is used in cases of haemorrhage and shock and to a lesser extent as part of the treatment of certain infectious diseases.

In cattle the donor and recipient are usually in the same herd. This fact lessens the risk of introducing infection and incompatibility does not arise.

But normal antibodies against the blood group factor-J are sometimes found in cattle. Thus if the donor's blood is J-positive and the recipient's blood contains normal antibody called anti-J the so-called transfusion reaction might be expected immediately following blood transfusion. These reactions are dyspnoea, muscular twisting, increased salivation and circulatory disturbances.

However, if an animal has been exposed to repeated blood transfusions, a different situation will arise. The animal will now have formed antibodies against the blood group antigens it does not have itself. It is therefore by no means unlikely that the blood of donor and the recipient are incompatible.

If this is so, transfusion will set off strong transfusion reactions. Such reaction can occur on the second or on subsequent blood transfusion.

Do all seas have tides?

Tides are caused due to the pull of the moon, and to a much smaller extent, the sun. In general, the larger the body of water, the more noticeable the tide. The height of the tide depends on the size, shape and depth of the sea in a given location. In enclosed seas like the Mediterranean Sea, there is hardly any tide at all, because it is surrounded by land on all sides. The rise and fall of the water may be only a few centimeters.

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Do all rivers run into the ocean?

Surprisingly enough, they don’t! The rivers flowing south from the Tassili Mountains in North Africa slow down to a trickle and disappear in the searing heat and scorching dryness of the Sahara sands. Sadly, even some of the world’s great rivers that used to flow into the ocean now fail to reach it. This is caused by water evaporation from dams and irrigation canals that lead to massive water loss.