Antonie van Leeuwenhoek, Father of Microbiology

Anton van Leeuwenhoek (October 24, 1632–August 30, 1723) invented the first practical microscopes and used them to become the first person to see and describe bacteria, among other microscopic discoveries.  Indeed, van Leeuwenhoeks work effectively refuted the doctrine of spontaneous generation, the theory that living organisms could spontaneously emerge from nonliving matter. His studies also led to the development of the sciences of bacteriology and protozoology. Fast Facts: Anton van Leeuwenhoek Known For:  Improvements to the microscope, discovery of bacteria, discovery of sperm, descriptions of all manner of microscopic cell structures (plant and animal), yeasts, molds, and moreAlso Known As: Antonie Van Leeuwenhoek, Antony Van LeeuwenhoekBorn:  Oct. 24, 1632 in Delft, HollandDied:  Aug. 30, 1723 in in Delft, HollandEducation:  Only basic educationPublished Works:  Arcana naturÅ“ detecta, 1695, a collection of his letters sent to the Royal Society of London, translated into Latin for the scientific communityAwards:  Member of the Royal Society of LondonSpouse(s): Barbara de Mey (m.1654–1666),  Cornelia Swalmius (m. 1671–1694)Children: MariaNotable Quote:  My work...was not pursued in order to gain the praise I now enjoy, but chiefly from a craving after knowledge. Early Life   Leeuwenhoek was born in Holland on October 24, 1632, and as a teenager he became an apprentice at a linen drapers shop. Although it doesnt seem a likely start to a life of science, from here Leeuwenhoek was set on a path to inventing his microscope. At the shop,  magnifying glasses were used to count the threads and inspect the quality of cloth. He was inspired and taught himself new methods for grinding and polishing tiny lenses of great curvature, which gave magnifications up to 275x (275 times the subjects original size), the finest known at that time. Contemporaneous Microscopes People had been using magnifying lenses since the 12th century and convex and concave lenses for vision correction since the 1200s and 1300s. In 1590, Dutch lens grinders Hans and Zacharias Janssen constructed a microscope with two lenses in a tube; though it may not have been the first microscope, it was a very early model. Also credited with the invention of the microscope about the same time was Hans Lippershey, the inventor of the telescope. Their work led to others research and development on telescopes and the modern compound microscope, such as Galileo Galilei, Italian astronomer, physicist, and engineer whose invention was the first given the name microscope. The compound microscopes of Leeuwenhoeks time had issues with blurry figures and distortions and could magnify only up to 30 or 40 times. Leeuwenhoek Microscope Leeuwenhoeks work on his tiny lenses led to the building of his microscopes, considered the first practical ones. They bore little resemblance to todays microscopes, however; they were more like very high-powered magnifying glasses and used only one lens instead of two. Other scientists didnt adopt Leeuwenhoeks versions of microscopes because of the difficulty in learning to use them.  They were small (about 2 inches long) and were used by holding ones eye close to the tiny lens and looking at a sample suspended on a pin. Leeuwenhoek Discoveries With these microscopes, though, he made the microbiological discoveries for which he is famous. Leeuwenhoek was the first to see and describe bacteria (1674), yeast plants, the teeming life in a drop of water (such as algae), and the circulation of blood corpuscles in capillaries. The word bacteria didnt exist yet, so he called these microscopic living organisms animalcules. During his long life, he used his lenses to make pioneer studies on an extraordinary variety of things—living and nonliving—and reported his findings in more than 100 letters to the Royal Society of England and the French Academy. Leeuwenhoeks first report to the Royal Society in 1673 described bee mouthparts, a louse, and a fungus. He studied the structure of plant cells and crystals, and the structure of human cells such as blood, muscle, skin, teeth, and hair. He even scraped the plaque from between his teeth to observe the bacteria there, which, Leeuwenhoek discovered, died after drinking coffee. He was the first to describe sperm and postulated that conception occurred when a sperm joined with an ovum, though his thought was that the ovum just served to feed the sperm. At the time, there were various theories of how babies formed, so Leeuwenhoeks studies of sperm and ovum of various species caused an uproar in the scientific community. It would be around 200 years before scientists would agree on the process. Leeuwenhoeks View on His Work Like his contemporary  Robert Hooke, Leeuwenhoek made some of the most important discoveries of early microscopy. In one letter from 1716, he wrote, My work, which Ive done for a long time, was not pursued in order to gain the praise I now enjoy, but chiefly from a craving after knowledge, which I notice resides in me more than in most other men. And therewithal, whenever I found out anything remarkable, I have thought it my duty to put down my discovery on paper, so that all ingenious people might be informed thereof. He did not editorialize on meanings of his observations and acknowledged he was not a scientist but merely an observer. Leeuwenhoek was not an artist either, but he worked with one on the drawings he submitted in his letters. Death Van Leeuwenhoek also contributed to science in one other way. In the final year of his life, he described the disease that took his life. Van Leeuwenhoek suffered from uncontrollable contractions of the diaphram, a condition now known as Van Leeuwenhoek disease. He died of the disease, also called diaphragmatic flutter, on August 30, 1723, in Delft. He is buried at the Oude Kerk (Old Church) in Delft. Legacy Some of Leeuwenhoeks discoveries could be verified at the time by other scientists, but some discoveries could not because his lenses were so superior to others microscopes and equipment. Some people had to come to him to see his work in person. Just 11 of Leeuwenhoeks 500 microscopes exist today. His instruments were made of gold and silver, and most were sold by his family after he died in 1723. Other scientists did not use his microscopes, as they were difficult to learn to use. Some improvements to the device occurred in the 1730s, but big improvements that led to todays compound microscopes didnt happen until the middle of the 19th century. Sources â€Å"Antonie Van Leeuwenhoek.†Ã‚  Famous Biologists Antonie Van Leeuwenhoek Comments, famousbiologists.org.Cobb, M. An Amazing 10 Years: The Discovery of Egg and Sperm in the 17th Century. Reproduction in Domestic Animals 47 (Suppl. 4; 2012), 2–6, Faculty of Life Sciences, University of Manchester, Manchester, UK.Lane, Nick. The Unseen World: Reflections on Leeuwenhoek (1677) ‘Concerning Little Animals.’  Philosophical Transactions of the Royal Society of London Series B, Biological Sciences 370 (1666) (April 19, 2015): 20140344.Samardhi, Himabindu Radford, Dorothy M. Fong, Kwun. (2010). Leeuwenhoeks disease: Diaphragmatic flutter in a cardiac patient. Cardiology in the Young. Cardiology in the Young. 20. 334 - 336.Van Leeuwenhoek, Anton. Letter of June 12, 1716, to the Royal Society, quoted by the University of California Museum of Paleontology, Berkeley.Vision Engineering. Later Developments.

Culture Is How People Live - 1264 Words

Culture is how people live. Society is everything made, learned, or shared by the individuals from a general public, including makings, opinions, practices, and material articles. People’s lifestyle vary from society to society. Culture is the way individuals in certain in a place do things regularly. Individuals have different personalities based on their upbringing. Most times, we can tell someone’s nationality by the way they dress. For instance, a typical American would have on a shirt, jean pant and a pair of sneakers. Subcultures are smaller cultural groups found in a larger culture. They are distinct from the larger culture in which they are found. For instance, in the U.S., there are subcultures such as the northeast, and the†¦show more content†¦Most people from the North dress more casual and other times formal than people from the South. Southerners tend to dress more relaxed than people from the North. People in the North also have a different way of speaking than people in the North, such as Northern people saying â€Å"Hey, you guys† versus Southern people saying â€Å"Hey y’all.† Northern people also have different ways of getting to their destinations quickly like taking a train, bus, cab, or walking, whereas most Southern people use a car to get to wherever they want to go as a result of transportation scarcity. Every college institution is referred to as a Subculture. They are referred to as a subculture because each college institution has different administrative systems by which they operate. Allen University runs their institution different from Benedict College. At Allen, we do not have classes on Friday but Benedict College, usually have classes on Friday. At Allen University, we make our own schedule against the following semester. However, in Benedict College, their academic advisor make the schedule for their assigned students. Also, at Allen University, we have the option of picking as many classes as we want and we are required to take the minimum of Seven (7) or more classes per semester. Allen University has several subcultures on campus. The Greek industries are considered subcultures. A subculture is a group that

The Effects of the Atomic Bomb Essay Example For Students

The Effects of the Atomic Bomb Essay The Atomic Bomb: Effects on Hiroshima and Mankind The nuclear bomb was the most devastating weapon ever created by man. It was developed between 1942 and 1945 during the second World War. The project to build the worlds first atomic weapon was called The Manhattan Project. The nuclear bomb was based on the idea of splitting an atom to create energy, this is called fission. Three bombs were created, Trinity, Little Boy, and Fat Man. Trinity was dropped on a test site in New Mexico on July 16, 1945, proving the theories, engineering and mathematics of the bomb to be correct. Shortly after that, not more than 2 months, the U.S. performed the first actual nuclear attack in the history of war. The bomb Little Boy was dropped on the town of Hiroshima, instantly killing thousands. Fat Man was dropped shortly after on the town of Nagasaki. After the bombing almost all scientist involved with the creation of the bomb regretted its construction and spoke out against the abolishment of nuclear weapons. The Manhattan Project was led by American physicists J. Robert Oppenheimer and directed by General Leslie Graves. The project employed over 130,000 people and the total cost by the end of production was nearly 2 billion dollars, 20 billion dollars in todays currency. Oppenheimers early education was at the Ethnical Culture School in New York. He took classes in math and science and many languages such as Greek, Latin, French, and German. He learned Dutch in only six weeks to give a speech in the Netherlands. He was also interested in classic and eastern philosophy. In 1939 rumor came to the U.S. that Germans had split the atom. The threat of the Nazis developing a nuclear weapon prompted President Roosevelt to establish The Manhattan Project. Oppenheimer set up a research lab in Los Alamos, New Mexico and brought the best minds in physics to work on the problem of creating a nuclear weapon. Although most the research and development was done in Los Alamos, there were over 30 other research locations throughout the project. After watching the first nuclear bomb test Oppenheimer was quoted as saying simply It works.. Now that the atomic bomb was proven to work the next question was where to drop it. Specialists in many fields were called on by the U. S. Army to help them decide on the best target for the atomic bomb. They considered many things while selecting the target such as the range the aircraft had to carry the bomb, the morale effect on the enemy, military importance of the target, and the geography of the target. The Army also wanted to be able to see the bombing take place (visual bombing) so the weather conditions had to be almost perfect, they wanted to witness the effects of the weapon. They also looked for closely built wooden frame structures that were easily susceptible to fire since the blast was expected to be the leading cause of damage while fire was to be second. The scientists in the Manhattan Project expected the blast radius to be around 1 mile therefore the target should have a densely built up area of that size. Also considered was the damage done by previous bombings, the target should have minimal damage by previous bombings so the effects of the bomb could be more accurately measured. After long analysis the Army chose Hiroshima and Nagasaki as the best possible targets. The city of Hiroshima is almost entirely flat, just above sea level and located on the Ota river. This was the perfect target geographically since it is flat and fully exposed to the blast from the bomb. Seventy-five percent of the population were jammed into a densely built area at the center of the city. Hiroshima was a highly important military target. .u9cbccd226efe5912a0f7f14fea640951 , .u9cbccd226efe5912a0f7f14fea640951 .postImageUrl , .u9cbccd226efe5912a0f7f14fea640951 .centered-text-area { min-height: 80px; position: relative; } .u9cbccd226efe5912a0f7f14fea640951 , .u9cbccd226efe5912a0f7f14fea640951:hover , .u9cbccd226efe5912a0f7f14fea640951:visited , .u9cbccd226efe5912a0f7f14fea640951:active { border:0!important; } .u9cbccd226efe5912a0f7f14fea640951 .clearfix:after { content: ""; display: table; clear: both; } .u9cbccd226efe5912a0f7f14fea640951 { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .u9cbccd226efe5912a0f7f14fea640951:active , .u9cbccd226efe5912a0f7f14fea640951:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .u9cbccd226efe5912a0f7f14fea640951 .centered-text-area { width: 100%; position: relative ; } .u9cbccd226efe5912a0f7f14fea640951 .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .u9cbccd226efe5912a0f7f14fea640951 .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .u9cbccd226efe5912a0f7f14fea640951 .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .u9cbccd226efe5912a0f7f14fea640951:hover .ctaButton { background-color: #34495E!important; } .u9cbccd226efe5912a0f7f14fea640951 .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .u9cbccd226efe5912a0f7f14fea640951 .u9cbccd226efe5912a0f7f14fea640951-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .u9cbccd226efe5912a0f7f14fea640951:after { content: ""; display: block; clear: both; } READ: Employment Skills Essay The Japanese 2nd Army was headquartered there, this commanded all Japanese defense in southern Japan. The city was also a communications center, storage point and troop assembly area. Outside the center of town the area was packed with small wooden workshops and wooden houses. Most industrial buildings in the area were also built with wooden frame construction. This made the city as a whole highly .

Alloy Definition and Examples in Chemistry

Alloy Definition and Examples in Chemistry An alloy is a substance made by melting two or more elements together, at least one of them metal. An alloy crystallizes upon cooling into a solid solution, mixture, or intermetallic compound. The components of alloys cannot be separated using a physical means. An alloy is homogeneous and retains the properties of a metal, even though it may include metalloids or nonmetals in its composition. Alternate Spellings: alloys, alloyed Alloy Examples Examples of alloys include stainless steel, brass, bronze, white gold, 14k gold, and  sterling silver. Although exceptions exist, most alloys are named for their primary or base metal, with an indication of other elements in order of mass percent. Uses of Alloys Over 90% of metal used is in the form of alloys. Alloys are used because their chemical and physical properties are superior for an application than that of the pure element components. Typical improvements include corrosion resistance, improved wear, special electrical or magnetic properties, and heat resistance. Other times, alloys are used because they retain the key properties of component metals, yet are less expensive. Example Alloys Steel: the name given to an alloy of iron with carbon, usually with other elements, such as nickel and cobalt. The other elements add a desired quality to the steel, such as hardness or tensile strength.Stainless Steel: another iron alloy, which typically contains chromium, nickel, and other elements to resist rust or corrosion.18k Gold: this is 75% gold. The other elements typically include copper, nickel, or zinc. This alloy retains the color and luster of pure gold, yet is harder and stronger, making it better suited for jewelry.Pewter: an alloy of tin, with other elements such as copper, lead, or antimony. The alloy is malleable, yet stronger than pure tin, plus it resists the phase change of tin that can make it crumble at low temperatures.Brass: a mixture of copper with zinc and sometimes other elements. Brass is hard and durable, making it suitable for plumbing fixtures and machined parts.Sterling Silver: is 92.5% silver with copper and other metals. Alloying silver makes it h arder and more durable, although the copper tends to lead to greenish-black oxidation (tarnish). Electrum: Some alloys, like electrum, occur naturally. This alloy of silver and gold was highly prized by ancient man.Meteoritic Iron: While meteorites may consist of any number of materials, some are natural alloys of iron and nickel, with extraterrestrial origins. These alloys were used by ancient cultures to make weapons and tools.Amalgams: These are mercury alloys. The mercury makes the alloy much like a paste. Amalgams may be used in  dental fillings, with the mercury intact, although another use is to spread the amalgam and then heat it to vaporize the mercury, leaving a coating of another metal.

Economics Dissertations How to Create a Masterpiece

Economics Dissertations How to Create a Masterpiece Most students who are undertaking the major of economics have got an element of economics dissertations during the final year of receiving the education. Basically, it may be the greatest writing project that a student has to fulfill if compared to the time, efforts, and dedication that are needed to write it. The economics is a young science that has a tremendous impact on the world. It finds and detects the peculiarities and develops personal theories regarding the tendencies in the world of finances and bank affairs. Points to Bring Economics Dissertation to Perfection With an abundance of thesis topics for economics papers, there will always be something interesting to investigate and put into practice. That is why in order to craft a real masterpiece in the science of economics, the author should attend to the following points while writing the assignment. Find a writing niche Before you set out on your investigation path, you should make a decision on where you will start your writing. You need to consider what field of economics you are interested in. It can be either macro- or microeconomic investigation. Conduct the investigation of the tendencies in the world of science and concentrate on finding the topic that will be applicable and practical for the society and experts of the science. You need to understand what contribution you can make to the fund of the world’s knowledge. Decide on the typology of economics writing The world of finances is composed of so many aspects that it is hard to imagine. The writer can formulate a personal economics theory and work on the arguments which will prove its applicability. The investigators of economic theories have got a potential of helping the society. It is possible to study the existing theories and conduct a comparative historical analysis of the background of the science. There is also an opportunity to develop either an empirical investigation or gathering of encyclopedia entries. All these types will be equally helpful, and it depends exclusively on the writer what topic is the most important for working on. Provide a mathematical analysis Economics is tightly connected with numbers as most of the investigation involves financial analysis and statistical data analysis. You should never ignore the necessity to present the calculations in your dissertation. It is usually presented in a practical part of the dissertation or in the appendixes. Prepare all the formulas beforehand so that it is easier to organize the whole paper in the most effective manner. Use modern technologies Sitting with a calculator and counting the statistical data manually will take a lot of your time. There are plenty of software solutions which were developed specifically for the economists. They contain all the basic formulas and can automatically calculate all the data that is inserted into the corresponding fields. Additionally, it is strongly advisable to create some charts and diagrams that will generalize all the ideas that will be described in the text. Moreover, it can become a superb visual aid for writing during the public defense of the dissertation. The information above would be applicable exclusively for writing the economics research project, but you shouldn’t also forget about general writing demands for dissertation writing that are standard for all types of writing as well as some looking facts to make the paper interesting. As a result, you will obtain an investigation paper of the ultimate quality. If you are looking for professional help with dissertation in economics, dont hesitate to contact our service right now.

Narrative Critical Analysis Essay Example | Topics and Well Written Essays - 750 words

Narrative Critical Analysis - Essay Example Patricia Hampl has done a brilliant job in explaining how memoir is a picture of reality and imagination and hence, an attempt by a writer to find his hidden ‘self’. Through her essay, Hampl proves that a memoir is not just a life story but also a medium of self discovery as it helps the writer not only in understanding the hidden self, but also in harmonizing the images and emotions stored in the memory, and in attaining the most desired inner peace. Analysis From my experience of writing a memory narrative, I have learnt that the event in the past reveals a lot more than what I have thought it to be. It has made me realize that events that leave an emotional impact on us are the ones that leave more impact on the memory. It has shown me that most of the times, it is not the event but the interpretations we make about them that makes it more or less important. Also, one single event can be seen differently by different people as they see it through their own personal an gle. This fact has been explored in a clear manner in the essay ‘Memory and Imagination,’ by Patricia Hampl. Memoir is an account of true events in life and hence, it is not fiction. Fiction is completely imaginative while memoir is real life story told by people. However, according to Hampl, memoir also has touch of imagination to it. Hence, it has shades of fiction. This is the reason Hampl also says that the first draft of the memoir is important. Hampl says that the first draft is like a fresh look and revelation of the truth. It is written without the barriers of the conscious mind and hence, has a deep meaning to it. The first draft is the real thing as it is not written with careful observation or restrain. When the writing flows without any carefulness, then it brings the hidden feelings, interpretations and emotions of the writer. This brings the deep hidden emotions and thoughts to the surface. This helps the writer in discovering his own self which is usually hidden in the unconscious mind. Hence, Hampl also says that if the first draft is written with careful attitude, then it is a failure. By this she means that carefully written first draft does not bring the hidden feelings in the unconscious and fails to help the writer discover his own self. Hence, Hampl also says that heart is the boss of writing. According to Hampl, the conscious and rational mind takes a back seat while writing. Memoir is written with the aid of memories of past. However, memory is not static or frozen aspects of life. They are molded into shapes and colors which are added to it through person’s eyes and mental opinion. When a person writes, his intuition, his wishes and his dreams are fulfilled. The memoir is written without the pressure of being completely truthful. Hence, a writer tries to fulfill his unfulfilled wishes and desires in the past by showing them as fulfilled in his memoir. Moreover, when a person writes a memoir, his rational mind is ove rpowered by his irrational and imaginative mind. Moreover, the fears, disappointments, weaknesses and sadness, which is guarded by the rational mind, are given an outlet through the memoir. This shows that the mind loses its grip on a writer when he is writing and his heart takes the control. Hence, Hampl says that heart is the boss when writing. Hampl is right when she says that heart is the boss of writing. I have experienced that when I am writing about my life, I tend to be more open, unburdened and relaxed about my experiences and descriptions.

President as global leader Essay Example | Topics and Well Written Essays - 500 words

President as global leader - Essay Example Prior to the onset of the Second World War presidents had only been interested in being leaders in the Western hemisphere, with the Monroe Doctrine asserted that America had the right as well as the duty to interfere with, or lead the countries of Central and Latin America.2 The only time that an American president tried to be a global leader was when Woodrow Wilson attempted to be one at the end of the First World War. Congress, who vetoed American membership of the League of Nations and returned to a policy of strict neutrality, overturned his efforts.3 In many respects the American president acting as a global leader was a consequence of American involvement in the Second World War, and also the Cold War, which followed on from it. President Roosevelt was able to portray himself as a global leader during the Second World War until his own death. The American use of the atomic bombs against Japan meant that President Truman could boast of being the most important global leader due to the Americans been the only nuclear power. The onset of the Cold War also ensured that America could not resort to a neutral foreign policy ever again. American presidents were in affect global leaders of the capitalist Western World, containing the spread of communism.4 Certainly in the Cold War period the majority of American presidents successfully presented themselves as being global leaders. Truman, Eisenhower, Kennedy, Johnson, Nixon, and Reagan all made viable claims about their status as global leaders. Presidents Carter and Ford were arguably less successful in that regard. The ability of these presidents to portray themselves as global leaders was shaped by internal and external factors as well as their own personalities. To a large extent all post-war American presidents have had the same constitutional powers as each other.5 In constitutional terms every American president has operated with actual as well as potential blocks to his or her