Koch’s Postulates
Introduction
Koch created four guidelines to determine the causal agents of disease in humans, animals, and plants. Koch proved that a disease-causing agent could be transferred from one organism to another and create the same illness. Isolation of pure cultures and the introduction of the disease-causing agent to a healthy organism will transmit the disease and infect the inoculated organism. Koch’s four guidelines by which one must follow to transmit a disease from an infected organism to a healthy one are as followed:
1. The specific organism should be shown to be present in all cases of animals suffering from a specific disease but should not be found in healthy animals.
2. The specific microorganism should be isolated from the diseased animal and grown in pure culture on artificial laboratory media.
3. This freshly isolated microorganism, when inoculated into a healthy laboratory animal, should cause the same disease seen in the original animal.
4. The microorganism should be reisolated in pure culture from the experimental infection.
In this exercise, Penicillium was utilized, a common, safe, mold. Certain species of Penicillium will spoil fruits, vegetables, grains, and grasses. Other species will ripen various chesses. Still, other species are used in the production of antibiotics. The species of Penicillium, italicum is provided for the lab because of its pronounced hyphae. Penicillium italicum, along with Penicillium digitatum attack citrus fruits post-harvest. In this experiment, the effect of Penicillium italicum on two types of citrus fruits and one non-citrus fruits were tested.
Materials & Methods
1. Pick several appropriate fruits.
2. Gently was fruit in cool, soapy water, using a scrub brush on the citrus fruits, then rinse thoroughly with cool running tap water.
3. Place citrus in a beaker and cover with a 10% bleach solution. Let soak for 10 minutes.
4. Rinse thoroughly with cool running tap water for 10 minutes.
5. Flame sterilize a teasing needle, cool, then pierce skin of disinfected fruit.
6. Unscrew cap on Penicilium italicum culture tube with one hand and flame the mouth of the tube.
7. Using the first three fingers of your writing hand, obtain a sterile applicator stick and remove a small sample of the fungus and smear over the puncture wound of the fruit.
8. Flame tube and recap. Discard swabs appropriately.
9. Obtain a second sample with a sterile applicator stick and smear over an unpunctured section of the fruit.
10. Flame tube and recap. Discard swabs appropriately.
11. Maintain a control for the experiment.
5. Two or more samples may be applied to each plate if they are kept
Place a clean, dry 125 mL Erlenmeyer flask on balance, and slowly dispense liquid bleach until there is about .5 g. Record the mass of bleach, and add 25 mL of de-ionized water and about 2 g of KI. Swirl contents until the KI dissolves. Then add 3 drops of 1 M H2SO4, mix, and let stand for 1 or 2 minutes.
René Descartes signifies a unique change compared to ancient and medieval traditions in many ways. The ancient and medieval traditions consist of ideals of which people impose meaning on things. These classical traditions also consist of how a person identity starts from outside of the body and the works its way inwards towards a complete person. Those traditions had a perception that humans began to analyzes themselves outside of themselves first before they analyze themselves internally. Descartes challenged the ancient and medieval traditions by having a different perception of how he came to know things. Descartes, instead of imposing meaning on things, he would derive meaning from things. He also challenged the classical traditions because
Another thing to note is that that a good car deserves a choice place in our lives. I am not advocating the need for a very expensive Car but one that would
CEMEX is a global cement company from Mexico that dates back to 1906. It was formally established in 1931 through a merger between Cementos Hildago and Cementos Portland Monterrey. Although initially it operated on a domestic level, various factors within its operating environment forced it to expand internationally. Before venturing into other markets, the company opted to capitalize on the ideal environment created the Mexican Government. Nevertheless, the Mexico 1982 economic crisis forced the Government to liberalize the Mexican market thus attracting foreign competitors. To counter the new competition, CEMEX opted to first divest its business, which was diversified across hotel management, engineering, petrochemicals, to focus on its core cement production business. It opted to avoid a hostile take over by foreign companies through consolidating its position in the domestic Market. Acquiring Cementos Anahuac and Cementos Tolteca was a strategic move that enabled it control 60% of Mexican market, becoming the world tenth biggest cement company. Probably motivated by the success of this strategy and the new acquired competitive scale, the company opted to internationalize. Acquisition was the preferred strategy of expansion. This strategy undoubtedly yielded unprecedented success over the years. By 2004, CEMEX had grown to be the 3rd largest building material company in the world, experienced an 18% annual growth rate in sales, and enjoyed a revenue of US$ 7.1 billion, just to mention a few.
It has been shown that the benefits of increased investment in the public transportation sector would apply to most, if not all, Americans. Whatever monetary costs Americans would have to meet would be met, if not completely overshadowed by the amount they would save on average. Therefore, based on the evidence available, one may conclude that it is not only necessary and proper, but also urgent to pursue an active agenda towards the increased funding and research of public transportation.
5.) One at a time, place your test tubes in the water bath and heat the first test tube to 25 , the second to 50 , the third to 75, and the last to 100 degrees c. Remeber to stir with your stirring rod every so often.
In 1818 Frankenstein was written by Mary Shelley. In Frankenstein, Victor Frankenstein brings a creature to life. The creature kills William, Henry Clerval, and Elizabeth. Victor had promised to make a female creature for the creature, but he did not fulfill his promise. This makes the creature enraged. The creature runs away and Victor follows him. Victor gets on a boat with Walton. Victor dies and the creature comes and is very sad that his creator has died. The creature says that he must end his suffering and he jumps into the ocean. In the novel Frankenstein, Shelley uses the theme of nature to show how it is like the characters of the story and how it affects the characters.
2. In the large beaker, put water and boil it completely. After that, remove the beaker from heat. 3. Sample tubes (A-D) should be labeled and capped tightly.
One of the main benefits of owning a car is convenience. A person can go to and from work, go shopping, go to the doctor, go to parties, go to practically everywhere without having to depend either on other people or on public transport...
In this society the cars aren’t just a luxury item. It has become necessity. For example people need to have a car to get around or used for jobs. And to some people it’s even a house to live in.
Some people believe that the benefits of the automobile far outweigh the consequences. These people enjoy their privacy and the convenience of the automobile. There are no schedules to keep track of. A person can come and go from a destination at their own free will. They also have the ability to travel and see scenery that people limited to public transportation cannot. Today there is about one car on the road for every person of driving age in the United States. People for alternative forms of transportation think that people who support cars should be penalized for using them. They believe that they should pay more taxes for the convenience of owning an automobile. In Europe, anti-auto policies are in effect and Europeans still buy cars. James Q. Wilson in "Cars and Their Enemies" gives the example, "Despite policies that penalize car use, make travel expensive, and restrict parking spaces, Europeans, once they can afford to do so, buy cars, and drive them" (306). Cars are just too convenient to get rid of.
Born in France on March 31st, 1596, Rene Descartes grew to be known as ‘The Father of Modern Philosophy”. Not only was Rene a philosophical man but he contributed greatly to Mathematics and his ideas have influenced our daily lives in a productive way. DesCartes was raised in a very religious christian family, his father was a member of the parliament and strongly believed in education at a young age. DesCartes studied at the Jesuit college at the mere age of eight. As a child and throughout his adulthood physical incapabilities enabled DesCartes to function as swift or promptly as his peers. Growing up and until the day of his death, Descartes’s health was always a major precaution he was forced to remain aware of. The Jesuit college granted him the immunity of resting in mornings before class. It was this education that led him to contribute philosophical and mathematical theories and devices that still hold a great value to mathematicians and everyday people even today in the 21st century. From a very young age he had interests in mathematics and analytical geometry. Descartes’s contributions to modern day society were affected by his young adulthood, soon he created mathematical and scientific ideas, and lastly philosophical ideas.
First of all, the difference is in the facility or convenience. Travelling on public transport could be a waste of time due to waiting for the bus especially in the rush hours’ time. It is quite hard to wait for a bus and whenever there is an urgent work and you have to reach somewhere in a hurry, you might get late due to waiting for a long period. In contrast to traveling on public transportation, driving your own car is more convenient and reliable. People can start their car and can go to anywhere that want without any wait or suffering from different kinds of problems. Going to an event or meeting can be helpful in your own car as compare to public transport as it can affect your personality.
Petrol prices generally go up, rarely coming down even when global fuel prices go down. This is an ongoing expense too, a car is useless without fuel. Picking a car with a smaller engine can save fuel and modern cars also have been designed with better fuel economy, but as I have already mentioned modern cars cost more money upfront.