SCIENCE PPT PRESENTATION

CONTENTS

• LOUIS PASTEUR• EDWARD JENNER• ALEXANDER FLEMING• LATEST TECHNIQUES

OF AGRICULTURE

1. LOUIS PASTEUR• Louis Pasteur was a French

chemist and microbiologist born in Dole. He is remembered for his remarkable breakthroughs in the causes and preventions of diseases. His discoveries reduced mortality from puerperal fever, and he created the first vaccine for rabies and anthrax. His experiments supported the germ theory and disease.

• The French chemist and biologist Louis Pasteur is famous for his germ theory and for the development of vaccines. He made major contributions to chemistry, medicine, and industry. His discovery that diseases are spread by microbes, which are living organisms—bacteria and viruses—that are invisible to the eye, saved countless lives all over the world.

Biography

• Louis Pasteur was born on December 27, 1822, in Dole in the Jura region of France, into the family of a poor tanner. Louis grew up in the town of Arbois He gained degrees in Letters and in Mathematical Sciences before entering the École Normale Supérieure, an elite college. After serving briefly as professor of physics at Dijon Lycée in 1848, he became professor of chemistry at the University of Strasbourg.

PASTEURIZATION

• He was best known to the general public for inventing a method to stop milk and wine from causing sickness, a process that came to be called pasteurization. He is regarded as one of the three main founders of microbiology.

FERMENTATION

• In 1852 Pasteur became chairman of the chemistry department at the University of Strasbourg, in Strasbourg, France. Here he began studying fermentation, a type of chemical process in which sugars are turned into alcohol. His work resulted in tremendous improvements in the brewing of beer and the making of wine.

• Pasteur proved that the bacillus itself was the disease agent, or the carrier of the disease.

• In 1881 Pasteur had convincing evidence that gentle heating of anthrax bacilli could so weaken its strength that it could be used to inoculate animals.

• In 1884, in collaboration with other investigators, Pasteur perfected a method of growing the virus in the tissues of rabbits. The virus could be weakened by exposing it to sterile air.

• A vaccine, or weakened form of the microbe, could then be prepared for injection. The success of this method was greeted with excitement all over the world.

• In 1865, two parasitic diseases called pébrine and flacherie were killing great numbers of silkworms at Alais. Pasteur worked several years proving it was a microbe attacking silkworm eggs which caused the disease, and that eliminating this microbe within silkworm nurseries would eradicate the disease.

• Pasteur also discovered anaerobiosis, whereby some micro organisms can develop and live without air or oxygen, called the Pasteur effect.

2. EDWARD JENNER

• Edward Anthony Jenner (17 May 1749 – 26 January 1823) was an English scientist who studied his natural surroundings in Berkeley, Gloucestershire. Jenner is widely credited as the pioneer of smallpox vaccine, and is sometimes referred to as the "Father of Immunology"; his works have been said to have "saved more lives than the work of any other man".

BIOGRAPHY

• Edward Jenner was born on 17 May 1749 in Berkeley, as the eighth of nine children. His father was the vicar of Berkeley and so Jenner received a strong basic education.

SMALL POX• He continued his research and reported it to

the Royal Society, who did not publish the initial report. After improvement and further work, he published a report of twenty-three cases. Some of his conclusions were correct, and some erroneous – modern microbiological and microscopic methods would make this easier to repeat.

• The medical establishment, as cautious then as now, considered his findings for some time before accepting them. Eventually vaccination was accepted, and in 1840 the British government banned variolation – the use of smallpox itself – and provided vaccination – using cowpox – free of charge.

• In 1796, he carried out his now famous experiment on eight-year-old James Phipps. Jenner inserted pus taken from a cowpox pustule and inserted it into an incision on the boy's arm. • He was testing his theory, drawn from the folklore of the countryside, that milkmaids who suffered the mild disease of cowpox never contracted smallpox, one of the greatest killers of the period, particularly among children.

• Jenner was widely ridiculed. Critics, especially the clergy, claimed it was repulsive and ungodly to inoculate someone with material from a diseased animal. A satirical cartoon of 1802 showed people who had been vaccinated sprouting cow's heads. But the obvious advantages of vaccination and the protection it provided won out, and vaccination soon became widespread.

• Jenner subsequently proved that having been inoculated with cowpox Phipps was immune to smallpox. He submitted a paper to the Royal Society in 1797 describing his experiment, but was told that his ideas were too revolutionary and that he needed more proof.

• Undaunted, Jenner experimented on several other children, including his own 11-month-old son. In 1798, the results were finally published and Jenner coined the word vaccine from the Latin 'vacca' for cow.

Jenner became famous and now spent much of his time researching and advising on developments in his vaccine. Jenner carried out research in a number of other areas of medicine and was also keen on fossil collecting and horticulture. He died on 26 January 1823.

3. ALEXANDER FLEMING

• Sir Alexander Fleming (6 August 1881 – 11 March 1955) was a Scottish biologist and pharmacologist. He wrote many articles on bacteriology, immunology, and chemotherapy. His best-known discoveries are the discovery of the enzyme lysozyme in 1923 and the antibiotic substance penicillin from the mold Penicillium notatum in 1928, for which he shared the Nobel Prize in Physiology or Medicine in 1945 with Howard Florey and Ernst Chain.

BIOGRAPHY•Alexander Fleming was born on the 6th of August, 1881 at Lochfield Farm, Darvel, Ayrshire. He went to work as a shipping clerk in London, where when he was aged 20, he inherited some money. He had always wanted to become a doctor, and so in 1901, he enrolled at St Mary's Hospital Medical School, London.

• He attended Louden Moor School, Darvel School, and Kilmarnock Academy before moving to London where he attended the Polytechnic. He spent four years in a shipping office before entering St. Mary's Medical School, London University.

• He qualified with distinction in 1906 and began research at St. Mary's under Sir Almroth Wright, a pioneer in vaccine therapy. He gained M.B., B.S., (London), with Gold Medal in 1908, and became a lecturer at St. Mary's until 1914.

• He served throughout World War I as a captain in the Army Medical Corps, being mentioned in dispatches, and in 1918 he returned to St.Mary's. He was elected Professor of the School in 1928 and Emeritus Professor of Bacteriology, University of London in 1948. He was elected Fellow of the Royal Society in 1943 and knighted in 1944.

• Sir Alexander wrote numerous papers on bacteriology, immunology and chemotherapy, including original descriptions of lysozyme and penicillin. They have been published in medical and scientific journals.

PENICILLIN• In 1928, Fleming was working on

the staphylococci bacteria - the kind that cause boils and sore throats, when, whilst he was examining some old bacterial plates that he noticed a mould had grown on one of his cultures. He saw what he believed was unusual in that some of the colonies of staphylococci that should ave been growing near the mould had disappeared.

• Fleming thought that the mould could be making something that was capable of destroying the bacteria. He did some more experiments and found that this was indeed the case. He cultured the mould by growing it in broth. The mould was later identified as Penicillium notatum which had produced what we now call penicillin.

ANTIBIOTICS• Fleming's accidental

discovery and isolation of penicillin in September 1928 marks the start of modern antibiotics. Fleming also discovered very early that bacteria developed antibiotic resistance whenever too little penicillin was used or when it was used for too short a period. Almroth Wright had predicted antibiotic resistance even before it was noticed during experiments.

• Fleming cautioned about the use of penicillin in his many speeches around the world. He cautioned not to use penicillin unless there was a properly diagnosed reason for it to be used, and that if it were used, never to use too little, or for too short a period, since these are the circumstances under which bacterial resistance to antibiotics develops.

4. LATEST TECHNIQUES OF AGRICULTURE

• Organic Cultivation 

Organic Cultivation is a type of farming that does not involve usage of chemicals like

chemical fertilizers and pesticides. In recent years, organic agriculture has gained

considerable importance. Major shift has been observed in the farming culture, due

to which several farmers have begun practicing this traditional method of

cultivation. Organic cultivation is proven as the means to produce safe foodstuffs and

preserve the environment.

BENEFITS OF ORGANIC CULTIVATION

• Spices produced from organic cultivation are premium in quality that the conventional spices.

• Organic farming does not involve heavy capital investment as required in chemical farming. The yearly costs incurred by practicing this type of farming are also low. Further most of the small farmers are dependent on natural rain for water.

• This types of farming requires abundance of traditional knowledge, which the farmers are well aware of. Moreover, in case of organic farming, the dependence on chemical know-how is not at all required.

•Crop rotation

Crop rotation is the practice of growing a series of dissimilar types of crops in the same area in sequential seasons for various benefits such as to avoid the build up of pathogens and pests that often occurs when one species is continuously cropped. Crop rotation also seeks to balance the fertility demands of various crops to avoid excessive depletion of soil nutrients.

• A traditional element of crop rotation is the replenishment of nitrogen through the use of green manure in sequence with cereals and other crops. It is one component of polyculture. Crop rotation can also improve soil structure and fertility by alternating deep-rooted and shallow-rooted plants.

METHOD • Crop rotation avoids a decrease in soil fertility,

as growing the same crop in the same place for many years in a row disproportionately depletes the soil of certain nutrients. With rotation, a crop that leaches the soil of one kind of nutrient is followed during the next growing season by a dissimilar crop that returns that nutrient to the soil or draws a different ratio of nutrients, for example, rice followed by cotton.

• By crop rotation farmers can keep their fields under continuous production, without the need to let them lie fallow, and reducing the need for artificial fertilizers, both of which can be expensive.

PURPOSE• Rotating crops adds nutrients to the

soil. Legumes, plants of the family Fabaceae, for instance, have nodules on their roots which contain nitrogen-fixing bacteria. It therefore makes good sense agriculturally to alternate them with cereals and other plants that require nitrates. An extremely common modern crop rotation is alternating soybeans and maize. In subsistence farming, it also makes good nutritional sense to grow beans and grain at the same time in different fields.

•EFFECTS• Crop rotation can greatly affect the

amount of soil lost from erosion by water. In areas that are highly susceptible to erosion, farm management practices such as zero and reduced tillage can be supplemented with specific crop rotation methods to reduce raindrop impact, sediment detachment, sediment transport, surface runoff, and soil loss.

CONTROLLED TRAFFIC FARMING

• Controlled traffic farming is used in combination with no-till or low-till farming to reduce compaction and help to rebuild soil structure. Conventional broad acre farming involves plowing the soil for every crop. This continual disturbance of the soil profile results in soil structure decline with implications for lower yield, falling nutrient leaves, decreased organic matter in the soil and

increasing compaction, or hard pan.

ADVANTAGES

• Controlled Traffic Farming provides optimum resource management by use of improved practices and new technology. The theory is clear, but the practice varies between different regions, industries and farming systems. Interaction between these, their advisers and technology suppliers is the focus of great debate.

CONVENTIONAL FARMING

•Conventional farming has the following major impacts on cropping: poor infiltration of water, leading to high evaporation loses in summer rain events, water logging in root zone when not over wet, the result being poor water use efficiency; hard pan problems which led to deep ripping; and soils that are very fine with very little air in the profile as a result of working the soil.

• Some farmers are working to reduce these problems by implementing controlled traffic farming techniques. Farmers sick of seeing their valuable topsoil blown away by wind or washed away by water are employing new farming techniques.

BED FARMING• One such technique is

bed farming where raised beds are used between vehicle tracks. The result is less water logging through improved drainage away from the bed and from the field. Other techniques are also used with raised beds, such as parallel lines down the bed to catch small rainfall events.

• By

•PRADYUMNA BHANDIWADVIII “A”

Thank you