Dietary fiber or roughage is the indigestible portion of vegetable-based food of our diet. While fibers do not contribute to any energy or nutrients, they do form an important part of the human intake, and lack of dietary fibers in one’s food can lead to several serious health implications ranging from constipation to diverticulitis or even colon cancer.

A diet rich in fibers provides several benefits such as:

It helps keep blood sugar levels in restraint by slowing down the release of glucose into the blood stream.

Certain forms of dietary fibers reduce plasma cholesterol and triglyceride levels.

Due to the water holding capacity, a fiber rich diet is more filling.

Diabetes Mellitus is one of the most common metabolic disorders that affect human kind. In spite of several breakthroughs in managing the disease, the exact etiology of diabetes is yet to be discovered. Studies point at several mechanisms leading to the disorder.

Genes play a deciding factor in the way an organism’s body functions. Several genome studies have indicated that mutation of the genes controlling the production of Human leukocyte antigen (HLA protein) results in Type1 diabetes, while variations in the gene TCF7L2 results in Type2 diabetes. Apart from the gene play, certain congenital autoimmune disorders result in the destruction of Beta cells of the pancreas resulting in late onset Type1 diabetes.

Diabetes was once known as the disease of the affluent, which suggested a connection between the disease and rich diet combined with physical inactivity. Modern science has confirmed this old adage. Obesity reduces insulin sensitivity of the cells resulting in Type2 diabetes. Moreover, high body fat percentage can adversely affect the pancreas, leading to reduced insulin secretion. 

Further complicating the etiology is the discovery of the Ob gene. This is a mutant gene found in obese individuals, which plays a role in passing Type2 diabetes to the next generation. Ob gene, purportedly leads to insulin toxicity resulting in age onset diabetes. At the same time, the presence of the gene in healthy and physically active individuals has shown to have no effect on insulin sensitivity, suggesting interplay of nature and nurture. 

Thus, according to the present understanding, diabetes mellitus is a result of a combination of genetic predisposition and faulty lifestyle (including both under nutrition and over nutrition). 

Another important step forward was made in learning about electricity. Otto von Guericke, a German announced that he had invented a machine that could create a vacuum, or the absence of air. There was a criticism all around of his idea. He paid little attention to the criticism until one day when the time had come to prove his ideas. He announced that he would now for the first time in public demonstrate his new vacuum pump. He would do it by taking the air out of a hollow globe. 

He took two hemispheres, or half globes made of copper. He showed that they could be put together to form a hollow ball. Attached to each half globe was a large metal ring. Von Guericke fitted the two halves together and took them apart several times to show how easily they could be joined or separated. Then he brought out his machine, the vacuum pump. It was an odd-looking contraption, with a handle on one side and a tube coming out the other. He once more fitted the two hemispheres together so that they formed a ball, and attached the tube. Then he turned to the people and stated that he would now remove the air from the globe with his pump.

He attached the tube to a valve in the sphere, and began to operate the handle of the pump. Up and down, up and down, he pumped as the machine hissed with each downward thrust. Soon he pumped slower and slower, just barely able to pump the handle. Finally, Von Guericke could move the handle no more, and wiping the perspiration from his brow, he announced, “I have removed the air from the globe! Inside the globe there now is – a vacuum”.

He went on and explained that there was force, or pressure, of air on the outside of the globe and since there was no air inside the ball, the pressure of air on the outside would prevent the two halves from separating. He then lifted the ball off the ground and held it up high by one of the rings so all could see. He shook it again and again. The other half did not fall away. He invited people to try to pull the two halves apart. A powerful man with all his might tried to pull but could not budge them.   

Four powerful horses were led in and hitched in pairs, one pair attached to each ring on the ball. A whip cracked. The horses pulled in opposite directions. Still the halves of the sphere remained together. Two more pairs of horses were brought on the scene and hitched to the first two horses. Now there were four horses pulled and pulled. Same result, the halves stayed together. More horses were added were added until there were eight on each side, sixteen in all, pulling and tugging with all their might. Finally a loud crack was heard. The halves separated. It had taken the strength of sixteen horses to overcome the pressure of the air. Von Guericke had proven his vacuum pump. This was the turning point in Von Guericke’s life and an important milestone in the story of electricity.

Scientists have discovered two genes that seem to protect people against severe malaria. Both are members of complex family of HLA genes on chromosome 6, which are involved in the body’s immune response to infection. The findings are exciting because hey offer clues to the body’s defense mechanism against the Plasmodium parasites that cause the disease. Also, they provide part of the answer to a riddle that has long puzzled geneticists: why have we evolved with so many different forms of HLA genes?

The HLA or human leucocyte antigen, genes are the most variable in the genome- that is, there are more alleles, of alternative forms, of them than any other group. Each one codes for an antigen on the surface of cells, and no two people’s antigens are the same.

The HLA antigens enable cells of the immune system to recognize foreign proteins invading the body. T cells will recognize such proteins only when they are bound to HLA antigens. Class I HLA genes govern the killer T cells and Class II genes govern the helper T cells, making them organize other cells of the immune system to produce specific antibodies.

In theory, scientists argue, different HLA genes must protect people against different infectious diseases so natural selection has resulted in the large variety of genes. However, strong evidence for this theory has been hard to find. But the picture has changed. This is the first piece of data that strongly supports the theory of why the genes are polymorphic.

The researchers analyzed the HLA signatures of 1800 children where a quarter of all child deaths are from malaria. They classified the children into four groups: those with severe malaria that had affected the brain; those with severe malaria causing anemia; those with mild malaria –that is, symptoms but no physiological damage; the healthy children who acted as controls. The control children were matched with the cases for age and district.

The team took blood samples from each individual and studies the sequence of DNA encoding their HLA genes, using gene probes and the polymerase chain reaction. In the Class II genes, they found that a particular unit of several linked alleles which is usually inherited together was much rarer in the group with severe malarial anaemia than in the healthy controls. This unit of alleles, know as a haplotype, was also rarer, but less markedly so in the group with cerebral malaria.

For the Class I genes, children with severe malaria- both cerebral and anaemic - were much less likely than controls to have a particular allele of the HLA-B series which is much commoner. The researchers calculate that the alleles offer between 40 and 50 per cent protection against severe malaria.