What You Should Know About Classical Ballet

Classical ballet had its origins in the entertainments of the ducal courts of 15th-century Italy, and it retains an elegance of style and deportment that can be traced back to this period when the dancers were kings, princes, and nobles. Balthasar de Beaujoyeulx was the choreographer of the first ballet to be called by that name. His Ballet Comique de la Reine, commissioned by Catherine de Médicis for the celebration of her sister's marriage, was performed in Paris in 1581. To Beaujoyeulx the art of ballet consisted of dancing bodies moving in geometric patterns to "the diverse harmonies of many instruments." This definition of ballet retains some validity, although the art has evolved into something more than, and something very different from, Beaujoyeulx's ballet.

The academic principles of classical ballet were firmly instituted when Louis XIV established the Royal Academy of Dancing in Paris in 1661. Since then, the elementary technical basis of ballet has been the five positions of the feet, with corresponding positions of the arms. Every classical ballet step or movement begins from one of these five positions and returns to one of them. However, classical ballet has since developed, expanded, and added to the five basic positions a large vocabulary of movements that are immediately recognizable to the trained eye of the dance student or the ballet follower. These steps and movements—arabesques, pirouettes, glissades, entrechats, and many others—were codified by a terminology in French that is still universally employed in the ballet schools and companies of every nation.

Dancing "on pointe," popularized by Marie Taglioni in La Sylphide in Paris in 1832, eventually became an integral part of classical ballet technique. Taglioni's great triumph in this role made dancing on the tips of the toes almost synonymous with ballet.

Classical ballet in its pure form reached its zenith in The Sleeping Beauty, first performed by the Imperial Mariinsky company of St. Petersburg in 1890. This production is a perfect example of the synthesis of dancing, drama, music, and decor. It combined the masterful choreography of Marius Petipa, a dazzling score by Tchaikovsky, a story beloved throughout the world, and elaborate scenery, costumes, and mechanical effects. There have since been many different productions of this work, and sections of it are performed by most ballet companies.

Physical Characteristics of Sea Anemone

Sea anemone is the popular name for some 1,000 species of polyp or coelenterate of the order Actiniaria in the class Anthozoa. These brightly colored, flowerlike animals are found in all seas, but they are generally more numerous and larger in temperate and warm waters. Most of them live singly, but some form colonies.

 

Unlike the closely related stone corals, sea anemones never form an internal limy skeleton but may form a superficial one in the ectoderm. Generally they live attached to rock pilings or the like, but a few burrow in sand or mud. Some fix themselves as commensals to shells inhabited by hermit crabs. A few are truly parasitic in jellyfishes.

Despite their popular name, only a few of these animals resemble anemone blossoms. The majority look like dahlias or chrysanthemums. The typical sea anemone has a stout, more or less cylindrical, body that is topped by a broad, flat disk. The disk contains a slitlike mouth surrounded by whorls of simple hollow tentacles, which resemble flower petals. From the mouth a short, tubular gullet, or esophagus, reaches into the cavity of the body. It is connected to the body walls by radiating septa, or mesenteries, that divide the body cavity into a corresponding number of sacs.

The esophagus communicates with the sacs through a central space into which the septa do not reach. A pair of ciliated grooves, or siphonoglyphs, extend along opposite sides of the esophagus and into the corresponding corners of the mouth. These always remain open and are the seat of inflowing and outflowing currents of water. The grooves provide both a means of respiration and an outlet for the removal of waste matter from the body.

The body walls, as well as the tentacles, which are outgrowths from them, are very contractile and largely composed of muscles arranged in a circular and a longitudinal layer. The circular layer is for extension; the longitudinal layer, for retraction. These muscles have special relations to the mesenteries. The mesenteries are vertical radiating septa reaching from the mouth disk or peristome to the base, and from the body wall to the esophagus, but ending freely below the esophagus. They are not strictly radial in arrangement but are grouped in pairs, almost always, like the tentacles, in some multiple of six. The mesenteries corresponding to the siphonoglyphs differ in structure from all of the others and are termed directive; the others form different classes according to the order and degree of development. The intermesenteric sacs may further communicate by one or two pores in each mesentery.

Along the edges of the septa the testes and ovaries are developed from the cells lining the gastric cavity. Digestive cells are also found in the same region, as well as an area filled with stinging thread cells, or nematocysts.

Sea anemones may be distinguished by the arrangement of their septa and tentacles and, less importantly, by their color and form. Most species, particularly the tropical varieties, are beautifully colored. The average size of a sea anemone is 21/2 to 3 inches (64–76 mm) in diameter and 4 inches (100 mm) in height.

Brief Biography of Ernst Abbe

Ernst Abbe (1840–1905) was a German physicist and industrialist who was a leader in the field of optics. Born in Eisenach in the grand duchy of Saxe-Weimar-Eisenach (later, part of Germany), on Jan. 23, 1840, Abbe studied physics at the universities of Göttingen and Jena, receiving his doctorate from the latter in 1861. He became a lecturer at Jena in 1863 and was appointed a professor of physics and mathematics there in 1870.

Abbe began working for the Carl Zeiss optical firm in 1866 and became wealthy after accepting a partnership in the company in 1876. He became the sole owner of the firm after Zeiss died in 1888 and reorganized it as a business cooperative in 1896. In 1891 he established the Carl Zeiss Foundation to promote the causes of scientific research and social betterment. Abbe died in Jena on Jan. 14, 1905.

Abbe in 1868 invented an apochromatic lens system that eliminated both the primary and secondary color distortion of microscopes and in 1870 used a condenser to give a high-powered even illumination in the field of view of microscopes. In 1874 he invented what became known as the Abbe refractometer, which measures the refractive index of substances.

Abbe developed a clearer theoretical understanding of the limits to optical magnification and discovered what was later named the Abbe sine condition, which defines how a lens can form a sharp image without the defects of coma and spherical aberration.

Facts about the City of Bratislava

Bratislava is the political, economic, and cultural capital of Slovakia. Bratislava (Hungarian, Pozsony; German, Pressburg) is the seat of the Slovak government, the administrative center of the Západoslovenský region (kraj), and a region in its own right. The city is located on the northern bank of the Danube, 35 miles (56 km) east of Vienna.

The Czechoslovakian Communist regime, which assumed control in Slovakia in 1947, encouraged the industrialization of all of Slovakia, and many industries, such as textiles, chemicals, metallurgy, and shipping, flourished in Bratislava.

Bratislava was already a strong point on the northern perimeter of the Roman Empire in the 1st century A.D., and it played a major role in medieval Europe as one of the relatively few fords or crossings of the Danube. A part of the Hungarian kingdom after the 10th century, the city became the capital of Hungary in the 16th and 17th centuries, when the Turks invaded southern and central Hungary. During the late 18th and 19th centuries, Bratislava sank into obscurity.

With the creation of Czechoslovakia in 1918, Bratislava became the center of a Slovak political and cultural revival. From 1939 to 1945 the city was the capital of an independent state, subject to German direction. After World War II, Bratislava was restored to Czech rule, and when Slovakia proclaimed independence in 1993, the city became the nation's capital.

The old sections of the city, with their churches and other buildings, some dating from the 15th century, are overshadowed by new housing developments. Several institutions of higher learning, such as the Univerzita Komenského Bratislava (Comenius University of Bratislava) and the Slovenská Akadémia Vied (Slovak Academy of Sciences), as well as a national theater and a number of museums make Bratislava a major cultural center

Definition of Urinary System

Urinary system is the body system that removes urea, uric acid, and other metabolic wastes from the blood and eliminates them from the body in the form of urine. This system consists of four main parts: the paired kidneys, the urinary bladder, the ureters, and the urethra.

The kidneys are brownish, bean-shaped organs located on the back wall of the abdominal cavity at about the level of the waist. Each kidney is about 4.5 inches (11 cm) long and 2 inches (5 cm) across. As blood flows through the kidney, about 3 million tiny tubular structures, called nephrons, selectively filter out the metabolic wastes. Water is also removed from the blood and together with the wastes forms the urine. From the nephrons, tiny collecting ducts carry the urine to larger ducts, which then empty into a large funnel-shaped area known as the renal pelvis.

Each kidney's renal pelvis opens into a ureter. The two ureters are nearly 13 inches (32 cm) long and about as thick as a pencil. They carry the urine into the bladder, their muscular walls propelling the urine along by a squeezing action. The ureters enter the bladder at a sharp angle, producing a flaplike valve that prevents any urine from flowing backward into the kidneys. A backflow could cause kidney damage.

The urinary bladder is a hollow, muscular, somewhat pear-shaped organ that, in an adult, holds 10 to 20 fluid ounces (296–592 ml) of urine. It lies behind the pubic bone and rises into the abdomen as it fills. Embedded in the walls of the bladder are nerve endings that send signals to the brain when the bladder needs to be emptied. Other nerves, upon receiving signals from the brain, stimulate the bladder walls to contract and force the urine out. The bladder normally empties completely with each urination.

From the bladder, the urine passes to the outside through the urethra. In men, the urethra measures approximately 7 inches (18 cm) in length and carries semen as well as urine. In women, the urethra is only about 1 or 1.5 inches (3–4 cm) long and carries only urine. In both men and women, the urethra has a slinglike sphincter muscle that allows for the voluntary control of urination.

Early Career of Barack Obama

Barack Obama, 44th president of the United States. Barack Hussein Obama was born on Aug. 4, 1961, in Honolulu to Barack Obama, Sr., and Ann Dunham. His father was a black man from Kenya; his mother, a white woman from Kansas. Leaving the family when Barack was only two years old, his father later returned to Kenya, where he subsequently worked as a government economist. Obama was brought up by his maternal grandparents in Hawaii and then, for a four-year period, by his mother and her second husband in Indonesia. He attended Occidental College in Los Angeles from 1979 to 1981 before transferring to Columbia University, from which he graduated with a bachelor's degree in political science in 1983.

Obama is the author of Dreams from My Father (1995) and The Audacity of Hope (2006). His 2008 book, Change We Can Believe In: Barack Obama's Plan to Renew America's Promise, outlined his vision for the country.

Early Career

In the mid-1980s, Obama moved to Chicago to help church-based groups with job-training programs, school reform, and other services. He received a law degree from Harvard Law School in 1991. While at Harvard he was the first African American president of the Harvard Law Review. After returning to Chicago, Obama organized a voter-registration drive for Bill Clinton during the 1992 presidential campaign; worked as a civil-rights lawyer; and served as a lecturer (1992–1996) and senior lecturer (1996–2004), specializing in constitutional law, at the University of Chicago Law School. He married Michelle Robinson, a lawyer, in 1992.

As a Democratic member of the Illinois Senate (1997–2004), Obama was chair of that chamber's Public Health and Welfare Committee. He helped to pass the Earned Income Tax Credit, which provided tax cuts for Illinois families, as well as legislation expanding early childhood education. He was a main sponsor of the state's first campaign finance reform legislation in 25 years. The charismatic senator delivered the inspiring keynote address at the 2004 Democratic National Convention. That November Obama ran for and won election as one of Illinois's U.S. senators. His congressional victory was one of the few bright spots for the Democrats that year, given the Republicans' retention of the presidency and their pickup of additional seats in both the Senate and the House.

In the Senate Obama was a member of the Senate Environment and Public Works, Veterans Affairs, and Foreign Relations committees. He was an early opponent of the Iraq War. His chief legislative accomplishment was to cosponsor, with Republican Richard Lugar, a major nuclear nonproliferation bill.

2008 Presidential Race

In February 2007 the senator, standing on the steps of the Old State Capitol in Springfield, Ill., announced that he would run for the presidency in 2008. Some 16 months later, on June 3, 2008, Obama had gained a sufficient number of delegates through the primaries, caucuses, and the pledges of superdelegates to become the presumptive Democratic presidential nominee. In so doing, he not only defeated his principal rival and former front-runner, Hillary Rodham Clinton, but also made history by becoming the first African American candidate to lead a major party ticket.

In staging his successful campaign for the nomination, Obama had finished first in more than a majority of the primaries and caucuses, including 11 consecutive contests in February that gave him momentum over Senator Clinton; raised over $300 million in campaign funds, largely through small Internet donations; and received some key endorsements, including those of Sen. Edward Kennedy and such former opponents for the nomination as former U.S. senator John Edwards of North Carolina and New Mexico's Gov. Bill Richardson.

Obama's campaign emphasized that he had been against the Iraq War from the beginning, a position that resonated with the primary voters, and one that set him part from Clinton. In addition, Obama presented himself as an outsider, ready to bring about change in Washington. Moreover, his oratorical powers helped him to connect with a broad range of voters. In March, after anti-American and racially charged sermons by Obama's former pastor, Jeremiah Wright, came to light, the senator delivered a well-received speech calling for racial healing. He later disassociated himself from Wright and resigned from the church. Once it became clear that Obama would be the presumptive nominee, the senator focused his attention on the race against Sen. John McCain, the presumptive Republican nominee, in the November election. Attracting the women and white working-class voters who had been so loyal to Senator Clinton were among the challenges that Obama faced.

Obama officially received the nomination of his political party at the Democratic National Convention, which was held in Denver on August 25–28. His acceptance speech was an extraordinary spectacle, delivered at INVESCO Field to an audience of over 84,000 people. At the time of this convention, Obama led McCain in most national polls and political observers considered him the front-runner. Political observers had also lauded his choice of Delaware senator Joseph Biden as his running mate. Whereas Obama was vulnerable to charges that he lacked sufficient experience in national politics and foreign policy to be president, Biden brought a record of three decades of service in Congress and a strong reputation for his knowledge of international affairs.

Opinion polls at this time showed that voters largely blamed the Republican Party and Pres. George W. Bush for an ailing economy. The polls also evidenced a strong public preference for a candidate who they believed could bring substantial change to national policy and who was seen as a better agent for change than McCain was. Throughout the campaign Obama emphasized McCain’s past support for many of the unpopular policies of the Bush administration.

Despite these advantages, the campaign became closely competitive after a successful Republican Party nominating convention and following McCain’s surprising choice of Alaska governor Sarah Palin as his vice-presidential running mate. Initially, the choice of Palin energized the conservative voting base of the GOP (Grand Old Party) and also caused a very significant shift in the polls among white female voters who had been leaning to Obama. Yet the race eventually shifted back to Obama, who commanded a significant lead after a series of three presidential debates and a vice-presidential debate, and most significantly after a stunning collapse of the U.S. banking sector.

The public largely considered the Democratic candidates Obama and Biden to have won the televised debates. Obama’s economic message—including calls for stronger government regulation of the financial industry—resonated positively with voters during a time of economic uncertainty. Obama successfully offered a message of optimism, promising to prevent American jobs from being shipped overseas, to provide a tax cut to 95% of the population, to create a national health-care plan, and to deliver a variety of other domestic programs that would improve peoples’ lives.

Another positive for Obama was the huge advantage he achieved in campaign fund-raising. Because he had earlier decided not to accept public matching funds, which would have limited his fund-raising, he was able to raise an enormous amount of money for his candidacy, particularly over the Internet. He used this advantage to establish a powerful grassroots operation throughout the country, as well as to significantly outspend his opponent in television advertising. In many of the critical battleground states in the electoral college, Obama ran as many as four times the number of television advertisements as his opponent. With all of these advantages, in the later weeks of the campaign Obama opened up a sizable lead in national opinion polls.

By the end of election day, Nov. 4, 2008, an estimated 133 million American voters had cast their ballots—the highest total in U.S. history. Obama won a commanding victory; he took some 53% of the vote to McCain's 46%, and 365 electoral votes to McCain's 173. Late on the night of the election, as it became clear that he was the first African American to be elected president, Obama addressed some 125,000 people in Chicago's Grant Park. His speech continued his campaign theme of hope but also warned of the daunting tasks that lay ahead. "Even as we celebrate tonight, we know the challenges that tomorrow will bring are the greatest of our lifetime—two wars, a planet in peril, the worst financial crisis in a century," he said. "There is new energy to harness and new jobs to be created; new schools to build and threats to meet and, for us to lead, alliances to repair."

Animal Facts: Common Tree Shrew (Tupaia glis)

The common tree shrew is a very emotional animal. When a male and female meet, it is either love or hate at first sight. This creature's strong feelings become most obvious when two are put into a cage together. About one pair in five seems to fall instantly in love. They nuzzle each other day and night. But most of the time, the forced meeting results in a violent fight. Each shrew then retreats as far away from the other as it can. In a cage, however, the couple is forced to look at one another. After a time, they literally die from the stress.

In nature, tree shrews that don't get along can flee. They are very territorial. The male marks the boundaries of his property with scents rubbed from a gland behind his neck. Scents that animals use to communicate in this way are called "pheromones."

A happy tree shrew couple usually mate on the very first day they meet. About 45 days later, the mother gives birth, usually to two babies. Each one weighs less than half an ounce. Normally she covers the babies with a special scent, or pheromone. This scent tells her mate to leave them alone. If she does not, he will undoubtedly eat them.

Tree shrews are more closely related to primates than they are to the mole-like shrews of North America and Europe. Like monkeys, tree shrews have large, well-developed brains and ape-like ears. 

Length of the Body: 5 to 7^1/2 inches

Length of the Tail: 5^1/2 to 7 inches
Weight: 2 to 6^1/2 ounces
Diet: fruits, insects, lizards, and small mammals
Number of Young: 1 to 4
Home: Southeast Asia