Microbiological culture is a principal tool used to diagnose infectious disease. In a microbial culture, a growth medium is provided for a specific agent. A sample taken from potentially diseased tissue or fluid is then tested for the presence of an infectious agent able to grow within that medium. Most pathogenic bacteria are easily grown on nutrient agar, a form of solid medium that supplies carbohydrates and proteins necessary for growth of a bacterium, along with copious amounts of water. A single bacterium will grow into a visible mound on the surface of the plate called a colony, which may be separated from other colonies or melded together into a "lawn". The size, color, shape and form of a colony is characteristic of the bacterial species, its specific genetic makeup (its strain), and the environment that supports its growth. Other ingredients are often added to the plate to aid in identification. Plates may contain substances that permit the growth of some bacteria and not others, or that change color in response to certain bacteria and not others. Bacteriological plates such as these are commonly used in the clinical identification of infectious bacterium. Microbial culture may also be used in the identification of viruses: the medium in this case being cells grown in culture that the virus can infect, and then alter or kill. In the case of viral identification, a region of dead cells results from viral growth, and is called a "plaque". Eukaryotic parasites may also be grown in culture as a means of identifying a particular agent.
What are most pathogenic bacteria easily grown on?
nutrient agar

In 1948, Eisenhower became President of Columbia University, an Ivy League university in New York City. The assignment was described as not being a good fit in either direction. During that year Eisenhower's memoir, Crusade in Europe, was published. Critics regarded it as one of the finest U.S. military memoirs, and it was a major financial success as well. Eisenhower's profit on the book was substantially aided by an unprecedented ruling by the U.S. Department of the Treasury that Eisenhower was not a professional writer, but rather, marketing the lifetime asset of his experiences, and thus he only had to pay capital gains tax on his $635,000 advance instead of the much higher personal tax rate. This ruling saved Eisenhower about $400,000.
What group of schools did Columbia University belong to?
Ivy League

In the spring of 1800, Napoleon and his troops crossed the Swiss Alps into Italy, aiming to surprise the Austrian armies that had reoccupied the peninsula when Napoleon was still in Egypt.[note 5] After a difficult crossing over the Alps, the French army entered the plains of Northern Italy virtually unopposed. While one French army approached from the north, the Austrians were busy with another stationed in Genoa, which was besieged by a substantial force. The fierce resistance of this French army, under André Masséna, gave the northern striking force precious time to carry out their operations with little interference. After spending several days looking for each other, the two armies finally collided at the Battle of Marengo on June 14. General Melas had a numerical advantage, fielding about 30,000 Austrian soldiers while Napoleon commanded 24,000 French troops. The battle began favorably for the Austrians as their initial attack surprised the French and gradually drove them back. Melas concluded that he'd won the battle and retired to his headquarters around 3 pm, leaving his subordinates in charge of pursuing the French. However, the French lines never broke during their tactical retreat; Napoleon constantly rode out among the troops urging them to stand and fight. Late in the afternoon, a full division under Desaix arrived on the field and dramatically reversed the tide of the battle. A series of artillery barrages and fortunate cavalry charges managed to decimate the Austrian army, which fled chaotically over the Bormida River back to Alessandria, leaving behind 14,000 casualties. The following day, the Austrian army agreed to abandon Northern Italy once more with the Convention of Alessandria, which granted them safe passage to friendly soil in exchange for their fortresses throughout the region.
In what year did Napoleon and his troops cross the Swiss Alps and enter Italy?
1800