Predictive Breeding - A New Milestone on the Road of Agricultural Success!

With the advent of genetic engineering, there has been a drastic change in the agricultural techniques. Gone are those days when man used to depend solely on nature for rainfall, soil fertility etc. Modern-man can toy with the genetic sequence and identify the part of genome which is beneficial for him.

                       

An attempt to improve the crop varieties began almost simultaneously with the agricultural practices. Around ten thousand years ago, man started to alter the genetic make up of crops without his knowledge. The conventional plant breeding practices began when early farmers selected the plant with desirable traits and saved its seeds for the next generation. Later with the knowledge of genetics, plant breeders were able to select the crops with desirable traits like faster growth, pest and disease resistance, sweeter fruits, larger seeds etc. Two plants having two different desirable characters were cross-pollinated artificially to obtain an offspring containing a mixture of these characters (hybrid variety). As a net result of these techniques new varieties of crops have developed which are significantly different from their wild relatives. Conventional breeding techniques largely depend on selection of superior varieties of crops and incorporation of desirable traits into future generations.

Genetic engineering has brought quantum change from conventional breeding practices and has introduced combination of genes which do not exist naturally. Sequencing of genomes of various plants has now become feasible with the faster progression in genetic engineering. Predictive breeding is an advanced technique which comes up with a promise of identifying the beneficial genes out of the entire genome. Genetic markers like SNPs (single nucleotide polymorphism) or minisatellites are used to construct linkage maps. The linkage maps help to identify the traits which are inherited together. The knowledge of genome sequence along with the linkage maps helps to associate the beneficial traits of the plant with specific parts of genome sequence.

Complicated genomes of polyploid crops pose a serious problem to predictive breeding. A cell of a polyploidy organism has more than two sets of homologous chromosomes and each set contains all the genes responsible for the biological traits of that organism. Professor Ian Bancroft took this as a challenge and identified the sequence of rapeseed (Brassica napus). This crop has been found to originate from two related species that is Brassica rapa and Brassica oleracea. Rapeseed (Brassica napus) was declared as a third leading source of vegetable oil in the world in the year 2000. Canola is the name given to Canadian oil that is extracted from certain varieties of Rapeseed. This oil is a rich source of essential fatty acids (omega-6 and omega-3 fatty acids in the ratio of 2:1). Apart from these it is also an important source of Biodiesel which can power motor vehicles. This oil is generally combined with fossil-fuel diesel in ratios varying from 2% to 20% of biodiesel. This does not damage the engine. Isn’t it an eco-friendly plant?

Sequencing the DNA of this plant directly was difficult because of its complicated genome. Hence they adopted a different strategy. Transcriptomes were sequenced from young juvenile leaves. Transcriptome is a set of all RNA molecules, including mRNA, rRNA, tRNA, and other non-coding RNA. It represents a small percentage of the genome. The sequence of a transcriptome mirrors the sequence of the DNA from which it was transcribed. This study gives an idea about all the genes which get expressed into proteins in that tissue. Sequence of transcriptome will act like a raw material for scientists struggling to locate the human friendly genes within the entire genome of the polyploid plants. Based on this improved varieties of seeds can be produced.

A large number of crops like potato, wheat, oat, sugarcane, cotton etc are polyploid and few crops amongst them are staple crops in certain parts of the world. Transcriptome sequencing will help the scientists to identify the desirable genes even in the absence of complete genome sequence. This new technique will make predictive breeding of crops with complicated genomes feasible.

Reference:

Bancroft I, Morgan C et al. Dissecting the genome of the polyploid crop oilseed rape by transcriptome sequencing.    Nat Biotechnol. 2011 Jul 31.

Honey! Why do you have such long life?

Honey is fructose rich sweet syrup, which is naturally prepared by honey bees. Honey bees collect the sweet nectar from the plants, refine it with the help of their saliva and regurgitate into the honey comb cells of the beehive. Fanning by the honey bees reduces the water content of honey.

Food substances have a restricted shelf life beyond which they tend to get decomposed and spoilt. Bacteria, fungi and yeasts are the main culprits behind food decay. There are many factors like, temperature, amount of water, pH of food substances etc which decide the rate of growth of these micro-organisms.

Honey is one of the miracle foods and it has been used by human beings since ages. Its world wide use is because of its multifarious benefits with an added longer shelf life. Honey in its raw form is pure and can stay for centuries together. During the excavation of Egyptian pyramids, honeycombs, sealed jars of honey were detected which were not decayed. This is a clear evidence for the fact that pure honey can be preserved for a considerably long period.

A sufficiently long life of honey is by virtue of its unique composition and its physical properties. Chemically honey is made up of 82% of carbohydrates. Fructose (38.2%) is the major monosaccharide in it. Other carbohydrates present in honey are glucose (31%), maltose (7%), and sucrose (1%).  It is rich in amino acid proline, vitamins and antioxidants. Moisture content of pure honey varies between 14%-18%.

Properties which prevent honey from decay are:

• Purity of honey is assessed by its moisture content. Water content below 20% indicates a good quality of honey. This concentration of water is insufficient for the airborne micro-organisms to breed and multiply.
• Honey has a very low pH ranging from 3 to 4.5. Acidic pH inhibits the growth of many micro-organisms.
• A higher concentration of sugar is another primary factor which curtails the growth of micro-organisms. The combination of high sugar concentration and low water content prevents it from getting fermented. Micro-organisms fail to sustain as they get dehydrated by the process of osmosis due to a high concentration of sugar. The same principle is used in the preservation of fruit jams.
• Hydrogen peroxide is produced by the enzyme glucose oxidase present in honey which is competent in inhibiting the microbial growth in honey.
• The percentage of proteins is relatively low. Microorganisms fail to live in such low nitrogenous content.
• Many microorganisms fail to digest fructose which is the major component of honey.

Honey finds a widespread application in our day to day life ranging from food to medicinal and therapeutic use. Its increased shelf life is like an added flavor. Pure honey properly stored in glass or ceramic containers with tight lids can be relished for ages together.

 

 

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Biological Water Purification - Some More Techniques

Palatable clean drinking water is becoming scarce in the present day world. Water table is decreasing day by day and the river water, even after treatment on a community basis, contains many contaminants. The levels of many pollutants like selenium, chromium, cadmium and arsenic have increased in water to dangerous levels. A long-term consumption of these pollutants may damage kidneys, liver and our nervous system. These also could lead to deadly diseases like cancer.

Off late we have different kinds of purifiers available in the market which are available at a very wide range of prices. These purifiers are associated with their own disadvantages, like, some of them consume energy in the form of electricity, some are made up of non biodegradable materials, some are very costly etc.

Some plants have been proved to be excellent for water purification. Plants like the Prickly pear cactus (Opuntia ficus-indica) or Moringa (Moringa oleifera) have the capacity to purify water. The Prickly pear cactus was used for water purification by Mexican communities long back during the 19th-century. As man marched ahead on the roads of civilization these facts were forgotten by him. He started his hunt for high technology methods of water purification.

A group of scientists from the University of South Florida in Tampa rediscovered the natural method of water purification using prickly pear cactus in 2010.

Norma Alcantar and her colleagues have used sophisticated microscopic analysis to prove the effects of cactus on dirty water.

Mucilage is glue like gummy substance secreted by plants which acts as a flocculant in water. It can precipitate substances into flakes and hence can remove substances like heavy metals (selenium, chromium, cadmium and arsenic) and even bacteria from water [1]. This thick gum is used by the plant to store water. When this magical mucilage is added to water, it sticks to the sediment particles and bacteria, which later drops down to the bottom of the water samples. According to Alcantar 98% of added bacteria, Bacillus cereus, was removed from the water sample. However, experiments are yet to be carried in natural water.

Apart from cactus there are some other plants also which help in water purification.

• Drumstick (Moringa Oleifera) – It is a drought resistant tree which can grow on a large number of poor soils including barren land. The seeds of this tree have coagulant properties and can purify turbid contaminated water. The seeds have to be crushed and the paste has to be mixed with water. The water has to be left undisturbed for an hour. The paste coagulates suspended impurities like bacteria, dirt etc and make water ready for domestic consumption. Dust and bacteria settle down which can be later be separated from pure water lying on the top. The protein component of these seeds acts as polyelectrolyte which can cross-link with charged particles.
• Nirmali (Strychnos potatorum) – The seeds of this plant are commonly used to clean water in India.

• Tulasi (Ocimum sanctum) – It is a famous medicinal plant and finds a widespread application in India. The seeds of this plant are also known for their water purification properties. However these seeds can purify water up to a certain extent and make it palatable for domestic purposes.

Many rural and underdeveloped countries have no access to the conventional water purification devices due to which people dwelling there are forced to drink contaminated water. Cactus plant and other plant products can be grown at many places at a lower cost. These plants can serve as a natural and renewable material for water filtration and at the same time save the lives of many people. It is a cost-effective alternative and also saves a lot of energy.

Reference:

Buttice AL, Alcantar NA et al. Removal of sediment and bacteria from water using green chemistry. Environ Sci Technol. 2010 May 1;44(9):3514-9.

Role of Salt in Hypertension

Hypertension or high blood pressure has become a common problem for the modern man. Modern lifestyle habits, nature of work, lack of exercise and poor dietary habits are some of the factors which are leading to hypertension in the present generation. A persistent high pressure increases the risk of a heart attack, stroke or congestive heart failure thus affecting the longevity of life. High blood pressure may even damage eyes and kidneys.

Hypertension or high blood pressure

Blood gets circulated throughout our body through arteries and veins. Our heart acts like a pumping machine which collects the deoxygenated blood and supplies the oxygenated blood to the body. The increase in blood pressure is noticed during two conditions, that is, during the increase in the volume of blood or when there is a constriction in the blood vessels. These two conditions lead to an elevation in the systemic arterial blood pressure.

How does the salt intake affect hypertension?

Table salt or sodium chloride is one of the main constituent of our diet. Apart from adding taste to our food it performs vital functions like water regulation in our body. It gets absorbed by our gastrointestinal tract and is excreted out by our kidneys. The excess of salt is flushed out by the kidneys to maintain the balance in our body. But if the salt intake is too high and if kidneys fail to cope up, the excess of salt gets accumulated in our bloodstream. Salt draws more water by the process of osmosis and leads to water retention in the blood vessels. This excess volume of blood creates pressure on the walls of the blood vessels leading to hypertension.

Dietary recommendations for the salt intake

We require 500 milligrams of salt every day for the normal functioning of the body. Our sodium intake should be kept between 2-3 grams.

Richness of sea salt

Research shows that hypertension is noted more in the cases of people consuming table salt which has 99.9 percent of pure sodium chloride. On the other hand sea salt which contains about 95 percent of sodium chloride, 4 percent of potassium chloride and the rest being a mixture of vital minerals like magnesium, iodine and trace elements has found to be a better option for hypertensive patients.

Sea salt is manufactured by the evaporation of sea water and usually exists in the form of crystals. The sea salt has a refreshing taste and is lightly flavored than the table salt.

Our body requires a perfect balance between the minerals like sodium and potassium. In fact a higher intake of sodium accompanied with a lower intake of potassium may lead hypertension. So the intake of sea salt is advisable for hypertensive patients.

Suggested measures to reduce salt intake

Salt intake has been directly associated with hypertension. Hence it is a common advice of all the doctors to reduce the salt intake. Slight modifications in our cooking practices help us to lead a better life. For example salt should be added during the process of cooking and not after the cooking is complete. Actually food should be cooked along with salt for at least 10 minutes.

Processed foods like chips, have a very high salt content. Salt is sprinkled over these items for better taste and this is harmful for our body. Even pickles and canned foods contain a higher content of salt. So it is advisable to avoid such processed foods.

Fresh fruits and vegetables are rich in nutrients and antioxidants. Eating these fruits and vegetables is good for our health.

Natural food items cooked in a lesser amount of sea salt are ideal for hypertensive patients.

 

Salts which when consumed in moderate quantities might control Bp. Buy on amazon

Natural Food Preservatives

Preserving food for long time was a necessity of mankind since time immemorial. The availability of certain food items was limited to a particular season. Man's desire to use them throughout the year motivated him to invent certain methods by which food items could be stored for a longer duration without a significant change in taste.

Food items can be categorized into perishable and non-perishable food items. Perishable items are those which get spoilt soon and are more prone to the attack of micro-organisms. Examples of some such items are vegetables, fruits, meat, eggs, milk etc. These items have a very short shelf life. On the other hand non-perishable foods are those which take a long duration to get spoilt like rice, wheat, oils, dried pulses etc.
The aim of using preservatives is to convert these perishable food items to non-perishable ones or extend the shelf-life. Food gets spoilt due to the attack of micro-organisms like bacteria, fungi, yeast etc. They bring some undesirable chemical changes in the food. Food preservatives inhibit these chemical changes through various ways.

Food preservatives are of two types: natural and artificial; and both try to maintain the quality, edibility and nutritive value of the foods.

Classification of Natural Food Preservatives

Depending on their mode of action, food preservatives are broadly classified into three kinds.

• Antimicrobial preservatives which inhibit the growth of the microorganisms
• Antioxidant preservatives which inhibit the oxidation of food ingredients like fats, lipids etc
• Preservatives which target the enzymes within the food stuffs and hence prevent the natural activities like ripening of food or post harvest ageing of food stuffs.

Some of the natural food preservatives include substances like salt, sugar, rosemary extract, essential oils, vinegar etc. Out of these, substances like salt, sugar and oils are used in our day-to-day life. Ongoing research is targeted towards the search of some new natural food preservatives. Let us discuss about a few preservatives in detail.

Salt: Salt has been used to preserve food items like meat and fish since ages. At very high concentrations of salt, the cells of the micro-organisms loose water and dehydrate by the process of osmosis. It inhibits the growth of bacteria, yeasts and molds by the process of osmosis. Salting of meat preserves it for years. During pickling, raw mangoes, tomatoes etc are treated with considerably large amounts of salt. Even some vegetables like cabbage cauliflower and cucumber can be preserved by pickling them with salting.

Sugar: Sugar is a carbohydrate and the mechanism by which it stores food is same as that of salt. This substance also dehydrates the microorganisms by the process of osmosis. There are two ways in which the food stuffs can be stored in sugar.

1. Thick concentrated sugar syrup can be prepared and the food substances can be immersed in it.
2. The food items can be cooked in sugar until sugar reaches the point of crystallization. A higher concentration of sugar sweetens the food and either inhibits the growth of microorganisms or kills them by the process of osmosis. Sugar is generally used to preserve fruits like apple, peach, pear, plum etc in the form of jams and jellies.

Vinegar: This acidic solution is prepared by the fermentation of sugar and water solution. The process of fermentation is carried beyond the alcohol stage. Vinegar contains acetic acid which kills the bacteria due to its acidity or lower pH. Vinegar is used to preserve meats and vegetables during pickling. Even during the process of canning vinegar is used to increase the shelf life of the food items.

Rosemary Extract: This is prepared by the distillation of rosemary leaves and is known for its pleasant aroma and flavor. This substance has been used as a preservative since ages because of its antioxidant properties. It prevents the oxidation of food stuffs thus retaining the flavor and color of the food. The natural compounds present in the Rosemary extract like phenolic diterpenes, rosmarinic acid, carnosol are responsible for its antioxidant properties.

Some Traditional Practices of Food Preservation

With the advancement in technology, man has conquered many difficult situations. In olden days, means of transport were not that efficient and moreover crops and vegetables grown in a particular area were very much dependent on the seasonal conditions in that area. These conditions encouraged people at that time to adapt certain practices which helped them to preserve food throughout the year. Some of these traditional practices are as follows -

• Indian plums, commonly known as ber in Hindi and regu pandu in Telugu, is a seasonal fruit which is generally seen in the market between January and March. A dish called regu adaa helps to preserve it for the whole year. To prepare this, seeds are removed and the fruits are beaten into a semi-solid paste. After adding salt, the paste is made into small biscuits and then sun dried.

• Cluster beans, commonly known as Guar-ki-phalli in Hindi and goru chikkudu in Telugu, is a nutritious vegetable. In order to preserve it, it is cut into medium size pieces, about one to one-and-a-half inch in length and soaked in buttermilk along with salt. This has to be soaked for a span of 24 hours and then sundried. These sundried pieces can be fried in oil and eaten along with rice.

• Coccinia cordifolia, commonly known as kundru in Hindi and dondakayi in Telugu, can be cut into pieces.  After applying salt to these pieces, they can be sun-dried and later these pieces can be stored for a long duration. Whenever required they can be fried and taken along with rice.

• Brinjal, commonly known as baingan in Hindi and vankai in Telugu, is a very commonly used vegetable across India. Even this vegetable can be cut into pieces and dried in sun after applying salt. Before cooking, the dried pieces have to be soaked for half-an-hour in water and then can be used to prepare a tasty curry along with tamarind water and jaggery.

• Mango - Good raw mangoes are available only in the summer season. They can be preserved in different forms of pickles. Apart from that small mango pieces can be sundried after application of salt. These mango pieces can be added to dhal through out the year.

It is true that nowadays we get all the food stuffs throughout the year with a variation in price. Fruits are no longer seasonal and they are ripened with the help of chemicals like ethylene. A few months back around November 2010 there was a heavy increase in the market price of all the vegetables. This crisis situation stayed for a span of three months but it affected many people. If we can adopt these traditional practices in our day to day life we can be ready to face any sort of odd situations. Not only this, we can prevent the wastage of huge quantities of food items also.

Acknowledgements:

• The information in this article is primarily sourced from discussions on preservation techniques with the author's mother-in-law, Mrs. Haimavathi, who has used the techniques in the past and still continues to follow some of these practices.

Pollinator Shortage Affects the Global Health

Pollinators play a central role in the reproductive propagation of flowering plants. Tiny insects or animals which act as pollinators include honey bees, butterflies, hummingbirds, bats, and ants. Plants yielding nutritionally rich fruits and vegetables are dependent to a large extent on pollinators.

Since past 50 years production of staple crops like rice, potato, wheat, yam etc has almost doubled. These crops mainly supply energy to our body and they are mostly wind-pollinated, self-pollinated, or vegetatively propagated. However our diet is incomplete without certain vital nutrients like vitamins and minerals and they are supplied by animal or insect pollinated plants.

According to the recent research conducted by Eilers et al. (2011) majority of oil produced from the plant sources comes from the plants which are animal pollinated. Vital nutrients like vitamin A, C and E come from animal pollinated fruits and vegetables. It has been estimated that approximately 70% of vitamin A and 98% of key nutrients like

Carotenoids, lycopene and ß-cryptoxanthin are obtained from plants which yield red, orange and yellow vegetables and fruits. These nutrients help us to fight cardiovascular diseases and cancer and are a source of antioxidants to the body. Plants like beans and dark green leafy vegetables are rich in folic acid which is very essential during pregnancy.

Eilers and his team have noticed a direct correlation between the increases in the yield of these plants with the increase in the number of pollinators. Apart from this the supply of certain vital minerals like calcium and fluorine and iron, increases with an increase in pollination of plants like beans, almonds and nuts.

Human intervention has reduced the number of pollinators to a very large extent. Deforestation over a vast area destroys the habitat and depletes the source of food for pollinators. This automatically reduces their number. Monoculture-based agricultural production that is planting similar crop year after year with a support of chemicals in the form of fertilizers and pesticides not only depletes the soil of its natural fertility but also reduces the number of pollinators. Some other factors which effect the pollinator population include, pesticides, insect and animal diseases and parasites.

A large number of nutrient supplements are available in market. But are they affordable to a common man belonging to the developing country? Moreover the synthesis of these supplements involves huge expenditure. Should we go ahead with the rampant use of chemicals to increase the food production or revert back to traditional eco-friendly farming practices? The choice is left to us.

References

Eilers EJ, Kremen C et al. Contribution of pollinator-mediated crops to nutrients in the human food supply. PLoS One. 2011;6(6):e21363

Manipulation of Plant’s Defense by Herbivores Poses Challenge to Entomologists

Plants have inherent defensive mechanism which protects them from their predators and phytopathogens. Their inability to move is largely complemented by the defensive adaptations which help the plants to survive and reproduce successfully. One of the most important defensive mechanisms is production of secondary metabolites. These metabolites are the chemical substances which are not involved in the normal photosynthetic process of the plants. They are alternatively known as allelochemicals and they can influence the behavior, growth, or survival of herbivores. Allelochemicals act as toxins to herbivores and in some cases also reduce the digestibility of plant cell wall.

Some external structural features on the stem and the leaves (prickles, spines, thorns etc) discourage herbivory to a very large extent. These mechanical defensive mechanisms deter, injure, or kill the grazer. Some defensive substances like wax, resins, lignins, etc. are released on the plants’ epidermis and prevent the herbivores from feeding on them. Apart from these, sensitivity to touch shown by Mimosa pudica is another example of defense mechanism in plants.

Herbivores form a primary link in the food chain, as they are the source of energy for organisms ranking higher in the food chain. Plants are the only source of food for herbivores and this led to the co-evolution of adaptations, which help them to acquire their food, irrespective of the defense mechanisms in plants. Some of these adaptations are:

·        synthesis of enzymes which can reduce the effect of secondary metabolites

·        existence of internal symbiotic bacteria, fungi, or protozoa which help to break down the plant cellulose so that it can be digested by the herbivore

·        mechanical adaptations like incisors in moths which helps them to eat soft leaves.

Amongst these adaptations, host manipulation is the most important mechanism by which herbivores feed on the plants in a better way. According to the recent research conducted by Renato Almeida Sarmento and his team, invasive spider mite Tetranychus evansi, manipulates its host (tomato), by interfering with signalling pathways involved in its defense mechanism [1].

Primary hosts for T. evansi are solanaceous crops like tomato, potato, tobacco etc. These mites puncture the leaves while feeding, leading to yellowing or whitening of leaves. Subsequently the leaves fall down and in case of severe attack the plant dies. The study conducted by Sarmento, suggests that T. evansi, manipulates the host defense mechanism by suppressing the induction of the salicylic acid and jasmonic acid signalling routes which are involved in plant defenses in tomato plant [1]. Salicylic acid and jasmonic acid play a vital role in plants immunity. Spider mites reduce the levels of inducible defense compounds and volatiles (example, proteinase inhibitors) which play a crucial role in plants defense.

Crops like tomato and potato find a widespread use across the world. Control of pathogens affecting these crops is a vital area of research. The result of the research by Sarmento, provides a better understanding of the plant–herbivore interactions. It opens the gateway for further research in two directions:

·        Biological control of Tetranychus evansi at an affordable cost to the farmer.

·        Developing crop varieties which are able to combat the manipulations by herbivores.

Reference:

Sarmento R, Lemos F et al. A herbivore that manipulates plant defense. Ecol Lett. 2011 March 14(3): 229–236.

Organ Donation – Saves another Life

During organ donation, solid organs like kidney, heart, pancreas, liver, bone marrow, eyes and limbs, are removed from the body of the donor and transplanted into the body of the recipient. Some of these organs can be preserved and utilized for future transplant. Vital organ like heart cannot be removed from a living person. Hence such organs are acquired from cadaver donors, who have died recently. Organs are separated from live donors in two cases

1)     When the organs are present in pairs. Example kidney

2)     When the removal of a portion of an organ does not effect the functioning of organ. Example liver, bone-marrow, pancreas

Legalization of transplantation of human organs has given rise to the concept of brain dead. Brain death is state of legal death. In this state the heart continues to beat and all the vital organs are kept alive and functional with the help of mechanical ventilation. This is a state during which the brain is dead and in an unrecoverable state – meaning – cannot be brought back to life. This condition is optimum to remove the organs for transplantation.

Consent of the Donors

Organ donation should happen only with the consent of the donor, if alive.  In most cases, the donor registers himself or herself as a donor where he agrees to donate specific organs on his death.  This is very common in the case of eye-donation and there are multiple organizations catering to this. After getting registered, the donors are issued a card which certifies their wish to donate organs. It is the donor’s responsibility to keep his family informed of his decision so that in case of death, the family can notify the organization that registered him.  The organizations try to reach the person in the earliest possible time to retrieve the organs after death. In some cases, the family of a victim of an accident may decide to donate the organs of the brain-dead victim. 

National Marrow Donor Program maintains a list of people willing to donate bone marrow to a stranger and here are some links given below where we can register ourselves as organ donors

http://www.medicareaustralia.gov.au/public/services/aodr/register.jsp

http://www.sgrh.com/subcat.aspx?id=51

http://www.organdonation.nhs.uk/ukt/roadshow.jsp

http://www.iaod.org/donor-registration-card-organ-donation.htm

Regulation of Organ Donation

Organ donation and transplant has always had a lot of regulation surrounding it. 

The reasons behind intense regulation are many, primary reason being exploitation and corruption. Seeing the high demand of organs, doctors and organ vendors try to exploit a common man by taking out his organs without his consent. Organ selling is legally banned in India but there are many areas where poor people are encouraged to sell their organs in return of money. On the ethical side, questions like - can a person who is mentally retarded be allowed to donate, can infants be donors, and so on have necessitated the stringent regulation of organ donation.

Does organ transplantation bring an end to the treatment procedure?

Once an organ is implanted into the body a long journey of recovery with intense medication begins. The body recognizes an implanted organ as a foreign body and the immune system wakes up. It tries to produce antibodies against the implanted organ and hence rejecting it. The patient is kept on strong immunosuppressant drugs for a long duration to allow the implanted organ to work properly.

Milestones Covered on the Road of Organ Transplant

• Transplantation of kidney was only feasible in the beginning but now transplantation of heart, liver, pancreas, skin, bone marrow, limbs intestines etc is also feasible.
• Now we have a wider choice as we can collect organs from both living and dead people.
• Discovery of strong immunosuppressant drugs has increased the success rate of organ transplants.
• Xenotransplantation or use of animal organs for human transplantation has takes us a step ahead. Example Chimpanzee kidneys were transplanted into patients with renal failure. A baboon heart was transplanted into a newborn infant.
• Syntheses of artificial organs for transplantation – Examples in this line are bionic eyes and ears, artificial heart.
• Organ from a single donor is being used for more than one patient by splitting it. Example split liver transplant where liver from a single donor was used for implantation into multiple recipients.
• Pioneering research – Stem cells have an enormous capacity to develop into any kind of tissue within the body including organs. Scientists aim to synthesize organs using the stem cells.

A large number of deaths have been reported to be due to the lack of organs ready for transplantation. Many patients live years together on expensive dialysis as they do not get a kidney donor. Lack of public awareness and inclination towards organ donation are main hurdles in this line. Galore of controversies and ethical issues surrounding organ donation accompanied by unawareness have made this procedure difficult. A voluntary organ donation saves another life.

Preservation of Suji or Semolina

Suji is vital ingredient in many Indian foods like upma, halwa, vada, laddoos, rava dosas etc. A porridge made of suji is a good weaning food for toddlers. Suji rava is prepared from wheat. The wheat grains are fed into rollers to remove the bran and germ. The remaining starchy part or the endosperm is broken down into pieces. A sieve made of net or mesh is used to separate the lighter part which is bran. The semolina pieces are further crushed to obtain fine flour.

Suji is a high calorie diet which provides energy for long period after consumption. It provides complex carbohydrates to our body. It is a processed food and vital components of grains like bran (fiber rich part) and germ (rich source of vitamin B complex, vitamin E, and minerals like Iron and calcium and magnesium) are lost during processing.

However nutritional value of any food item depends a lot on the method of preparation also. Many dishes like suji roti, rava-ragi rotis, rava idlis, rava dosas etc can be prepared using very less amount of oil. This will reduce the fat intake and also reduce the cholesterol levels. We can also add some grated vegetables in these dishes to supplement other nutritional requirements. We can prepare a wide variety of yummy dishes by slightly changing the formula of cooking. Isn’t that great about suji!

Porridge of suji with milk and sugar is cherished by infants. This gets easily digested and can be supplemented with smashed vegetables and fruits for a wholesome diet. Suji is generally stored in containers on the shelf and does not require refrigeration. Rava can be considered to be good until the rava granules are separate like that of sugar. However upon infestation, it starts forming threads. We can increase the shelf life of suji. All we need to do is fry siji for a few minutes over a low flame. After frying for few minutes the colour of rava turns out to be light brown accompanied with nice aroma. This should be cooled properly and then packed in air tight containers. This technique extends the shelf life of suji. Even after this if we find any signs of infestation it should be sun dried and used as soon as possible.

Introduced Species – Effect on Biodiversity

Introduction of an exotic, non-native species into the distributional range, either deliberately or accidentally by human activity many-a-times poses a serious threat to the local habitat. A habitat containing all indigenous varieties tries to balance and control each species living within its limits. An introduced species has no enemies to control it; hence they slowly out number the native species and compete with them for the available resources.

Threats to biodiversity are many like habitat destruction by forest clearing, release of poisonous gasses due to industrialization etc. Out of all these threats introduction of exotic species ranks second. In fact, native biodiversity is affected more by introduced species rather than by pollution, harvest, and disease combined.

Some of these species are also being used as biological weapons as they cause mass destruction of ecosystem.

Examples of Damage to Biodiversity

Species are habitat-specific and can thrive only in a particular habitat but introduced species change the entire habitat and cause a major threat to biodiversity.

• Australian paperbark tree was introduced which replaced native plants, such as sawgrass, over a wide range of about 400,000 acres of south Florida. Australian paperbark tree had a combination of traits like flammable leaves, spongy outer bark and litter which can increase fire frequency and intensity. The uncontrolled spread of paperbark made many birds and mammals extinct as they were adapted to the native plant community.

Some other invasive species, do not change a habitat, but pose a threat to a single species. Sometimes they even destroy the entire groups of them in various ways.

• Brown tree-snake, is a predator which was introduced from Admiralty Islands in cargo. This brown tree snake has affected forests of Guam by eliminating ten of the eleven native bird species.

Some times the impact of invaders is subtle but destroys the native species at the same time.

• In North America native red squirrels are being driven to extinction by gray squirrels. Both these species compete for nuts and gray squirrels are more efficient than the native species. Such competition for resources is difficult to observe, but loss of a native species is the end result.

An interesting example amongst plants is that of acacia and the eucalyptus. These species were brought from Australia as a part of afforestation programmes. These are quick growing plants and were encouraged as the demand for wood had also increased. But these plants are known for their large number of disadvantages like:

• These trees shade the ground and the leaves that are shed do not allow other plants to grow.
• These trees do not decompose easily
• During the rains there is heavy erosion and poor percolation in the areas rich in these trees.

Only a few Introduced species are beneficial. Like most of our food crops (rice), onion, chilies and pets. The statistics of damaging introduced species is startling. The solution to this problem is stringent quarantine rules at all entry and exit points like airports, harbours, border crossing areas etc. 

Such proactive measures to check this problem will allow the existing plants and animals to flourish in their natural surroundings and habitat.

Control Measures of Soil Pollution

The natural resource, soil, is the thin layer of organic and inorganic materials that covers the Earth's rocky surface. Soil formation involves a large number of factors and is a time taking process. Mechanical weathering of rocks due to temperature changes, wind, moving water, lichens are a few of the contributing factors.

Pollutants like toxic compounds, radioactive materials, salts, chemicals, when added to the soil, deteriorate the quality, texture and mineral content of the soil. This leads to soil pollution. Soil pollutants disturb the biological balance of the organisms in the soil. The adverse effect of this contamination is reduced soil fertility affecting plant and animal growth.

Major causes of soil pollution are:

• Random use of fertilizers
• Random use of pesticides, insecticides and herbicides
• Disposal of large quantities of solid waste
• Deforestation and soil erosion
• Addition of industrial contaminants
• Dumping of radioactive wastes

Control of soil pollution

Various steps suggested in order to control soil pollution are as follows:

Reducing chemical fertilizer and pesticide use

As the soil erosion has become a major cause of concern we need to adopt the three R's: Reduce, Reuse, and Recycle in order to minimize the usage of fertilizers and pesticides.

Biofertilizers are the best alternatives for chemical fertilizers. They are microorganisms which are used to increase the fertility and growth capacity of soil. This process of Biofertilization also reduces the need for pesticides and fungicides.

Practice of crop rotation – Leguminous plants can fix atmospheric nitrogen and hence enhance the soil fertility. These plants can be grown in between the crops which absorb a lot of soil nutrients.

Recycling of materials

Recycling and reusing of materials such as glass containers, plastic bags, paper, cloth etc. at domestic levels rather than disposing, reduces the solid waste pollution. Use of plastic bags has increased drastically. Paper bags or jute bags can be a good alternative for them. Toys made up of clay can be a good source of amusement for kids. A complete ban on the use of plastics is advisable.

Reforestation

Wastelands, soil erosion and floods can be controlled by reforestation. Huge forests have become prey to man’s greed. It takes years together to reform a forest. Every individual on earth should decide to plant trees to save our planet earth.

Treatment of waste

Biological treatment of the waste using anaerobic microorganisms, such as methanogens and acetogens is advisable as it helps to break down the soil wastes into a less toxic and biodegradable form. Industrial and radioactive wastes should be properly treated before leaving them to soil.

It is high time the man realizes the importance of the rich top soil and takes necessary steps to protect it from pollutants. Soil is an asset and there is no substitute for this. Wide stretches of desserts created by human beings are laughing at us. When we cannot create tanks and tanks of natural fertile soil should we not stop destroying it?

The Cry of a Hungry Child

Food is the basic necessity of human being and it is sad to know that at least 925 million people across the world are deprived of it. According to the statistics provided by worldhunger.org among these 925 million people, at least 578 million people are from Asian and Pacific region. A maximum number of people suffering from undernourishment are from developing countries.

It is sad that children are most liable victims of malnourishment. Children deprived from food for a sufficiently long span of time suffer from serious forms of Protein Energy Malnutrition. This situation arises due to the insufficient supply of nutrients especially proteins and energy to the body to meet its demands. A malnourished or undernourished child falls prey to many diseases like malaria, measles, diarrhea etc. Most of the deaths of children below 5 years of age are reported to be due to Protein Energy Malnutrition.

Reasons behind hunger from the economic point of view are many, like poverty and uneven distribution of money which is a primary cause of hunger. Poverty means lack of resources and ability to purchase food. Since ages it has been seen the rich people have access to all resources and tend to become further rich whereas the poor become poorer.

Some other reasons include economic crisis across the world and inadequate supply of food due to neglect towards agriculture. Another major factor which adds to all these is the wastage of food across the world. Food wastage statistics are quite saddening. The trend of wasting food has crept slowly from rich countries like America to developing countries.

Wastage of food begins at the producer level (farmer) and continues through the distribution channel till the house hold level. If we add up the wastage at each level it shows a considerable amount which can perhaps save many children from malnourishment. Vegetables are stored to increase the price in the market and if in this process they are spoilt they are simply thrown away. A vegetable seller throws away huge quantities of vegetables at the end of day rather than selling them at a lower price just because he has to maintain the market price. Similarly distribution channels, publicize the damage to stored food to artificially increase the prices. Tons and tons of packed food just go as waste. The reason behind this is the expiry date. How nice it would have been if they could have planned and distributed them amongst the people living in slums just before reaching their expiry date.

Did you ever think before throwing food into the dustbin at the restaurant or at home? Now-a-days it is common to see heaps of wasted food dumped outside a reception hall or a restaurant. Food wastage at the house hold level has also become common these days. The wasted food is not only a problem to the environment but it also increases the number of street dogs, rats, bacteria etc thus spoiling the balance of ecosystem. Are we not contributing to hunger and imbalance in ecosystem?

Back in the olden days our grandparents used to teach us not to leave even a single particle of food. Evidence of this can be found in one of our great epics Mahabharata where Lord Krishna fills up his stomach with a single rice grain and asks Draupadi not to waste that. Social and moral values have vanished away as the earning capacity of a few people has increased. Can we not take steps to stop food wastage and save a child who is crying because of hunger?

Relaxation of Abdominal Muscles

A group of muscles located on the front side of the body which lie between the ribs and the pelvis region are known as abdominal muscles. These muscles support the movement of the trunk and hold the vital organs of the abdomen in place together.
Body muscles are responsible for the movement of the whole body or its parts. They are able to covert chemical energy to mechanical energy. Fundamental properties of muscles are flexibility, excitability, conductivity and summation.

Various Abdominal Muscles

The four major abdominal muscles are as follows:

• Transversus Abdominis - These are the deepest muscles which influence the body posture. These muscles are found wrapped around the torso.
• 
  The Internal Oblique Muscles - A pair of muscles which reside on either side of the torso are said to be internal oblique muscles. These muscles modulate the body posture to a large extent. Some vital functions like rotation of the spine and lateral flexion are performed by these muscles.
• 
  External Oblique muscles - This pair of muscles like internal oblique muscles are also present on either side of torso. These muscles are located superficially and have less effect on maintenance of body posture. These muscles help the Internal Oblique Muscles in rotation of the spine and lateral flexion.
• 
  Rectus Abdominus muscle -These muscles are the most superficial muscles of the abdomen which maintain the fitness of the abdomen.

Conditions of Stress 

Professional athletes are usually subjected to abdominal muscle strain when their muscles are subjected to high amount of stress. In fact a situation of abdominal strain can arise to any common man. Simple daily activities like repeated lifting of heavy weights may also lead to abdominal strain. Such adverse situation can be treated by proper medication. However as the common saying goes "prevention is better than cure", it is better to subject our muscles to proper relaxation than getting used to medication.
Abdominal muscles are naturally stressed out during pregnancy. It is good to keep the muscles in good condition for easy delivery. In addition to this proper relaxation and abdominal exercises help the mother to regain her strength after delivery.

How to relax abdominal muscles? 

According to Harvard professor of medicine, Herbert Benson, a relaxed state is just opposite to the state of stress. Our body has the capacity to achieve this relaxed state which is a deep state of rest. This state is associated with decrease in breathing rate, heart rate, blood pressure, oxygen consumption, muscle tension, and active thinking. There are various methods by which we can relax our abdominal muscles.

Breathing exercises
These exercises include abdominal breathing which is quite different from shallow chest breathing. Abdominal breathing involves diaphragm which is the large muscle located between the chest and the abdomen. They increase the lung capacity and at the same time relax the abdominal muscles optimally.

Yoga 
Some basic yoga poses like Virabhadrasana, Bhujangasana, Marjarasana, Navasana etc help to strengthen our abdominal muscles and provide them with proper relaxation.

Advice to the modern man

Present day man is subjected to various kinds of stressful conditions. Due to his busy schedule he often feels that there is no time left for relaxation techniques. By setting aside 20-30 minutes and practicing the relaxation techniques daily he can improve his general health and longevity of life.

Regulatory Mechanism in Animals

Living organisms especially, mammals and birds (with few exceptions), tend to maintain a stable state by maintaining a constant internal environment. These animals are also known as endothermic animals. This phenomenon of regulation is known as homeostasis.

On the other hand ectothermic animals like reptiles, insects, amphibians, arachnids and fish show certain behavioral adaptations to regulate their internal conditions. For example, reptiles raise their body temperature in the morning by resting on sun-heated rocks.

Homeostatic Regulation

Mammals and birds can maintain a constant body temperature and hence are known as warm blooded creatures. During the cold season these animals convert food into energy. On the other hand, cold blooded animals become sluggish in cold conditions and often go into hibernation.

Homeostasis is responsible for regulation of many other factors like, constant blood pH, blood glucose, salt and water concentration etc. In many cases homeostatic regulation is controlled by the release of hormones into blood.

However processes like simple diffusion also help to maintain a proper balance.

Maintenance of constant water and glucose levels are done in the following ways-

• An increase in water concentration within the body is sensed by certain osmoreceptors situated on the hypothalamus. The chemical message is sent from the hypothalamus to the pituitary gland which secretes ADH hormone. The anti-diuretic hormone acts on the kidneys affecting the permeability of the tubules. This in turn regulates the water levels within the body.

• Blood glucose levels are maintained at constant levels within the body with the help of hormones like Insulin and Glucagon. Both of these hormones are secreted by the pancreas and these hormones target the liver. A higher levels of glucose in the blood stimulates a higher secretion of insulin and a lesser secretion of glucagon and when the levels of glucose is lesser in blood, the levels of secretion of both the hormones are reversed. The liver in turn either facilitates the conversion of glucose to glycogen or allows the breakdown of glycogen to glucose units.

Feed Back Mechanism in Animals

Feed back mechanism controls the regulation within the body and is made up of three interdependent components. The changes in the environment are sensed and recorded by the receptors. The stimulus is sent from the receptor to the control centre which is generally the brain. The control centre generates a response to the stimulus and sends the signal to the effectors which are organs like muscles. After the effector organs receive the stimulus from the control centre they can show an enhanced change in positive feedback mechanism or a depressed change in case of negative feedback mechanism.

Any disturbance to homeostasis disturbs the internal environment and leads to various diseases. Diseases like diabetes, hypoglycemia, dehydration, gout etc are the net result of homeostatic imbalance.

Biological Water Purification

Palatable clean drinking water is becoming scarce in the present day world. Water table is decreasing day by day and the river water, even after treatment on a community basis, contains many contaminants. The levels of many pollutants like selenium, chromium, cadmium and arsenic have increased in water to dangerous levels. A long-term consumption of these pollutants may damage kidneys, liver and our nervous system. These also could lead to deadly diseases like cancer.

Off late we have different kinds of purifiers available in the market which are available at a very wide range of prices. These purifiers are associated with their own disadvantages, like, some of them consume energy in the form of electricity, some are made up of non biodegradable materials, some are very costly etc.

Some plants have been proved to be excellent for water purification. Plants like the Prickly pear cactus (Opuntia ficus-indica) or Moringa (Moringa oleifera) have the capacity to purify water. The Prickly pear cactus was used for water purification by Mexican communities long back during the 19th-century. As man marched ahead on the roads of civilization these facts were forgotten by him. He started his hunt for high technology methods of water purification.

A group of scientists from the University of South Florida in Tampa rediscovered the natural method of water purification using prickly pear cactus in 2010.

Norma Alcantar and her colleagues have used sophisticated microscopic analysis to prove the effects of cactus on dirty water.

Mucilage is glue like gummy substance secreted by plants which acts as a flocculant in water. It can precipitate substances into flakes and hence can remove substances like heavy metals (selenium, chromium, cadmium and arsenic) and even bacteria from water [1]. This thick gum is used by the plant to store water. When this magical mucilage is added to water, it sticks to the sediment particles and bacteria, which later drops down to the bottom of the water samples. According to Alcantar 98% of added bacteria, Bacillus cereus, was removed from the water sample. However, experiments are yet to be carried in natural water.

Many rural and underdeveloped countries have no access to the conventional water purification devices due to which people dwelling there are forced to drink contaminated water. Cactus plant can be grown at many places at a lower cost. This plant can serve as a natural and renewable material for water filtration and at the same time save the lives of many people. It is a cost-effective alternative and also saves a lot of energy.

Reference:

Buttice AL, Alcantar NA et al. Removal of sediment and bacteria from water using green chemistry. Environ Sci Technol. 2010 May 1;44(9):3514-9.