Biography.

Early life.

Henie was born in 1912 in Kristiania (now Oslo) Norway; she was the only daughter of Wilhelm Henie (1872–1937), a prosperous Norwegian furrier, and his wife, Selma Lochmann-Nielsen (1888–1961). In addition to the income from the fur business, both of Henie's parents had inherited wealth. Wilhelm Henie had been a one-time World Cycling Champion and the Henie children were encouraged to take up a variety of sports at a young age. Henie initially showed talent at skiing, then followed her older brother, Leif, to take up figure skating. As a girl Henie also was a nationally ranked tennis player, and a skilled swimmer and equestrienne. Once Henie began serious training as a figure skater, her formal schooling ended. She was educated by tutors, and her father hired the best experts in the world, including the famous Russian ballerina, Tamara Karsavina, to transform his daughter into a sporting celebrity.

Competitive career.

Henie won her first major competition, the senior Norwegian championships, at the age of 10. She then placed eighth in a field of eight at the 1924 Winter Olympics, at the age of eleven. During the 1924 program, she skated over to the side of the rink several times to ask her coach for directions, but by the next Olympiad, she needed no such assistance.  Henie won the first of an unprecedented ten consecutive World Figure Skating Championships in 1927 at the age of fourteen. The results of 1927 World Championships, where Henie won in 3–2 decision (or 7 vs. 8 ordinal points) over the defending Olympic and World Champion Herma Szabo of Austria, was controversial, as three of the five judges that gave Henie first-place ordinals were Norwegian (1 + 1 + 1 + 2 + 2 = 7 points) while Szabo received first-place ordinals from an Austrian and a German Judge (1 + 1 + 2 + 2 + 2 = 8 points). Henie went on to win first of her three Olympic gold medals the following year, became one of the youngest figure skating Olympic champions. She defended her Olympic titles in 1932 and in 1936, and her world titles annually until 1936. She also won six consecutive European championships from 1931 to 1936. Henie's unprecedented three Olympic gold medals haven't been matched by any ladies' single skater since; neither are her achievements as ten-time consecutive World Champion. While Irina Slutskaya of Russia won her seventh European Championship in 2006 to become the most successful ladies' skater in European Championships, Henie retains record of most consecutive titles, sharing it with Katarina Witt of Eastern Germany/Germany (1983–1988).  Towards the end of her career, she began to be strongly challenged by younger skaters including Cecilia Colledge, Megan Taylor, and Hedy Stenuf. However, she held off these competitors and went on to win her third Olympic title at the 1936 Winter Olympics, albeit in very controversial circumstances with Cecilia Colledge finishing a very close second. Indeed, after the school figures section at the 1936 Olympic competition, Colledge and Henie were virtually neck and neck with Colledge trailing by just a few points. As Sandra Stevenson recounted in her article in "The Independent" of 21 April 2008, "the closeness [of the competition] infuriated Henie, who, when the result for that section was posted on a wall in the competitors' lounge, swiped the piece of paper and tore it into little pieces. The draw for the free skating [then] came under suspicion after Henie landed the plum position of skating last, while Colledge had to perform second of the 26 competitors. The early start was seen as a disadvantage, with the audience not yet whipped into a clapping frenzy and the judges known to become freer with their higher marks as the event proceeded. Years later, a fairer, staggered draw was adopted to counteract this situation".  During her competitive career, Henie traveled widely and worked with a variety of foreign coaches. At home in Oslo, she trained at Frogner Stadium, where her coaches included Hjørdis Olsen and Oscar Holte. During the latter part of her competitive career she was coached primarily by the American Howard Nicholson in London. In addition to traveling to train and compete, she was much in demand as a performer at figure skating exhibitions in both Europe and North America. Henie became so popular with the public that police had to be called out for crowd control on her appearances in various disparate cities such as Prague and New York City. It was an open secret that, in spite of the strict amateurism requirements of the time, Wilhelm Henie demanded "expense money" for his daughter's skating appearances. Both of Henie's parents had given up their own pursuits in Norway—leaving Leif to run the fur business—in order to accompany Sonja on her travels and act as her managers.  Henie is credited with being the first figure skater to adopt the short skirt costume in figure skating, wear white boots, and make use of dance choreography. Her innovative skating techniques and glamorous demeanor transformed the sport permanently and confirmed its acceptance as a legitimate sport in the Winter Olympics.

Professional and film career.

After the 1936 World Figure Skating Championships, Henie gave up her amateur status and took up a career as a professional performer in acting and live shows. While still a girl, Henie had decided that she wanted to move to California and become a movie star when her competitive days were over, without considering that her thick accent might hinder her acting ambitions.  In 1936, following a successful ice show in Los Angeles orchestrated by her father to launch her film career, Hollywood studio chief Darryl Zanuck signed her to a long term contract at Twentieth Century Fox, which made her one of the highest-paid actresses of the time. After the success of her first film, "One in a Million" (1936), Henie's position was assured and she became increasingly demanding in her business dealings with Zanuck. Henie also insisted on having total control of the skating numbers in her films such as "Second Fiddle" (1939).  Henie tried to break the musical comedy mould with the anti-Nazi film "Everything Happens at Night" (1939) and "It's a Pleasure" (1945), a skating variation of the often-told "A Star Is Born" tale about alcoholic-star-in-decline-helps-newcomer-up. It was her only film shot in Technicolor, but it was not as huge at the box office as her other films and also proved her limitations as a dramatic actress in her only dramatic film.  When Zanuck realized her limits in the pseudo-dramatic vein, he cast her in more musical comedies; "Sun Valley Serenade" (1941) with Glenn Miller, John Payne, The Nicholas Brothers, and hit songs such as "In the Mood", "Chattanooga Choo Choo", "It Happened in Sun Valley", and "I Know Why (And So Do You)", followed by "Iceland" (1942) with Jack Oakie, Payne, and the hit song "There Will Never Be Another You", and finally "Wintertime" (1943) with Cesar Romero, Carole Landis, Cornel Wilde, and Oakie. Sonja had by now developed a comedy flair and these films were all among the top box-office hits for 20th Century-Fox the respective years. Eight Sonja Henie movies crossed the magical $100 million domestic gross mark. That is a percentage of 72.72% of her movies listed. Happy Landing (1938) was her biggest box office hit.  In addition to her film career at Fox from 1936 to 1943, Henie formed a business arrangement with Arthur Wirtz, who produced her touring ice shows under the name of "Hollywood Ice Revue". Wirtz also acted as Henie's financial advisor. At the time, figure skating and ice shows were not yet an established form of entertainment in the United States. Henie's popularity as a film actress attracted many new fans and instituted skating shows as a popular new entertainment. Throughout the 1940s, Henie and Wirtz produced lavish musical ice skating extravaganzas at Rockefeller Center's Center Theatre attracting millions of ticket buyers.  At the height of her fame, Henie brought as much as $2 million per year from her shows and touring activities. She also had numerous lucrative endorsement contracts, and deals to market skates, clothing, jewelry, dolls, and other merchandise branded with her name. These activities made her one of the wealthiest women in the world in her time.  Henie broke off her arrangement with Wirtz in 1950 and for the next three seasons produced her own tours under the name "Sonja Henie Ice Revue". It was an ill-advised decision to set herself up in competition with Wirtz, whose shows now featured the new Olympic champion Barbara Ann Scott. Since Wirtz controlled the best arenas and dates, Henie was left playing smaller venues and markets already saturated by other touring ice shows such as Ice Capades. The collapse of a section of bleachers during a show in Baltimore, Maryland, in 1952 compounded the tour's legal and financial woes.  In 1953, Henie formed a new partnership with Morris Chalfen to appear in his European "Holiday On Ice" tour, which proved to be a great success. She produced her own show at New York's Roxy Theatre in January 1956. However, a subsequent South American tour in 1956 was a disaster. Henie was drinking heavily at that time and could no longer keep up with the demands of touring, and this marked her retirement from skating. She did try to make a film series at her own expense; a series that would serve as a travelogue to several cities. Paris and London were mentioned, but only "Hello London" (1958) was made with her own backing, co-starring Michael Wilding and special guest star Stanley Holloway. While her ice show numbers were still worth watching, the film received few distributors and poor reviews, ending her film career.  Her autobiography "Mitt livs eventyr", was published in 1938 which was translated and released as "Wings on My Feet" in 1940, and which was republished in a revised edition in 1954. At the time of her death, Henie was planning a comeback for a television special that would have aired in January 1970. She was to have danced to "Lara's Theme" from "Doctor Zhivago".

Nazi controversy.

Henie's connections with Adolf Hitler and other high-ranking Nazi officials made her the subject of controversy before, during, and after World War II. During her amateur skating career, she performed often in Germany and was a favorite of German audiences and of Hitler personally. As a wealthy celebrity, she moved in the same social circles as royalty and heads of state and made Hitler's acquaintance as a matter of course. During the shooting of "Second Fiddle" (1939), she greeted the then Crown-Prince couple of Norway Olav and Märtha during their US tour. Through the years, her shows and later art exhibitions drew the attention of such people as Princess Margaret, Countess of Snowdon and Gustaf VI Adolf of Sweden and she met with them.  Controversy appeared first when Henie greeted Hitler with a Nazi salute at the 1936 Winter Olympics in Garmisch-Partenkirchen and after the Games she accepted an invitation to lunch with Hitler at his resort home in nearby Berchtesgaden, where Hitler presented Henie with an autographed photo with a lengthy inscription. She was strongly denounced in the Norwegian press for this. In her revised 1954 biography, she states that no Norwegian judge was in the panel for the 1936 Olympics—as she was entitled to as a Norwegian. She therefore made the most of it and won her third Olympic medal. When she—as a gold medal winner—passed Hitler's tribune with silver medalist Cecilia Colledge and bronze medalist Vivi-Anne Hultén, neither she nor the others honored Hitler with the Nazi salute. The 1936 European Figure Skating Championships also took place in Berlin and neither Henie, Colledge, nor Megan Taylor paid obeisance to Hitler.  In her film "Everything Happens at Night" (1939), Ray Milland and Robert Cummings star as rival reporters hot on the trail of Hugo Norden (Maurice Moscovich). Norden, a Nobel Prize winner, was supposedly murdered by the Gestapo, but is rumored to be in hiding and writing anonymous dispatches advocating world peace. When Geoffrey and Ken track Norden to a small village in the Swiss Alps, they soon find themselves competing over the affections of beautiful Louise (Henie), who has a deeper connection to the missing Nobel laureate than the reporters realize. When Geoffrey and Ken get so distracted by romance that they begin to neglect their assignments, it almost leads to disaster as the Gestapo sets out to silence Norden once and for all. Released on 22 December 1939, it was banned in Nazi Germany.  Through her 1940 marriage to Dan Topping she had become an American citizen. As such, she was not eligible to speak Norway's cause and with producer Alexander Korda, who was set to produce the propaganda film That Hamilton Woman, could have faced deportation. The Senate Subcommittee (Senate Foreign Relations) dealt with such matters. After the bombing of Pearl Harbor, when America was no longer neutral, Henie pulled in uniform and visited and gave money to Little Norway. All Norwegians got free tickets to her shows during the war and she paid and held parties for them.  During the occupation of Norway by Nazi Germany, German troops saw Hitler's autographed photo prominently displayed at the piano in the Henie family home in Landøya, Asker. As a result, none of Henie's properties in Norway were confiscated or damaged by the Germans. Henie became a naturalized citizen of the United States in 1940. Like many Hollywood stars, she supported the U.S. war effort through USO and similar activities. After the Japanese attack, she invited the boys from Little Norway to her ice shows, gave the mechanics a plane as well a substantial sum of money to their educational fund. But her first rejection before the US entered the war was never to be forgotten. For this, she was condemned by many Norwegians and Norwegian-Americans. After the war, Henie was mindful that many of her countrymen considered her to be a quisling. However, she made a triumphant return to Norway with the Holiday on Ice tour in 1953 and 1955. The Norwegian Royal Family attended both events and indeed attended her funeral in 1969. The Royal Family were very mindful of whom they supported after the war and Norwegians looked to them as role models in that respect.

Personal life.

Henie was married three times, to Dan Topping (1940–1946), Winthrop Gardiner Jr. (1949–1956), and the Norwegian shipping magnate and art patron Niels Onstad (1956–1969) (her death). After her retirement in 1956, Henie and Onstad settled in Oslo and accumulated a large collection of modern art that formed the basis for the Henie Onstad Kunstsenter at Høvikodden in Bærum near Oslo.  She studied in Oslo together with Martin Stixrud and Erna Andersen who was her competitor and skate club member.

Death.

Henie was diagnosed with chronic lymphocytic leukemia in the mid-1960s. She died of the disease at age 57 in 1969 during a flight from Paris to Oslo. She is buried with Onstad in Oslo on the hilltop overlooking the Henie Onstad Art Centre.  Sonja Henie films gross https://www.ultimatemovierankings.com/sonja-henie-movies/

Sonja Henie (8 April 1912 – 12 October 1969) was a Norwegian figure skater and film star. She was a three-time Olympic Champion (1928, 1932, 1936) in women's Singles, a ten-time World Champion (1927–1936) and a six-time European Champion (1931–1936). Henie won more Olympic and World titles than any other ladies' figure skater. At the height of her acting career, she was one of the highest-paid stars in Hollywood and starred in a series of box-office hits, including "Thin Ice" (1937), Happy Landing (1938 film), "My Lucky Star" (1938), "Second Fiddle" (1939) and "Sun Valley Serenade" (1941).

Sonja Henie (8. dubna 1912, Oslo - 12. října 1969) byla norská krasobruslařka a filmová herečka. Třikrát vyhrála olympijské hry, desetkrát světový šampionát a šestkrát mistrovství Evropy.


Life.

Childhood.

Felix Mendelssohn was born on 3 February 1809, in Hamburg, at the time an independent city-state, in the same house where, a year later, the dedicatee and first performer of his Violin Concerto, Ferdinand David, would be born. Mendelssohn's father, the banker Abraham Mendelssohn, was the son of the German Jewish philosopher Moses Mendelssohn, whose family was prominent in the German Jewish community. Until his baptism at age seven, Mendelssohn was brought up largely without religion. His mother, Lea Salomon, was a member of the Itzig family and a sister of Jakob Salomon Bartholdy. Mendelssohn was the second of four children; his older sister Fanny also displayed exceptional and precocious musical talent.  The family moved to Berlin in 1811,

Surname.

Abraham Mendelssohn renounced the Jewish religion prior to Felix's birth; he and his wife decided not to have Felix circumcised, in contravention of the Jewish tradition. Felix and his siblings were at first brought up without religious education; on March 21, 1816, they were baptized in a private ceremony in the family's Berlin apartment by the Reformed Protestant minister of the Jerusalem Church, at which time Felix was given the additional names Jakob Ludwig. Abraham and his wife Lea were baptised in 1822, and formally adopted the surname Mendelssohn Bartholdy (which they had used since

Career.

Musical education.

Mendelssohn began taking piano lessons from his mother when he was six, and at seven was tutored by Marie Bigot in Paris. Later in Berlin, all four Mendelssohn children studied piano with Ludwig Berger, who was himself a former student of Muzio Clementi. From at least May 1819 Mendelssohn (initially with his sister Fanny) studied counterpoint and composition with Carl Friedrich Zelter in Berlin. This was an important influence on his future career. Zelter had almost certainly been recommended as a teacher by his

Early maturity.

Mendelssohn probably made his first public concert appearance at the age of nine, when he participated in a chamber music concert accompanying a horn duo. He was a prolific composer from an early age. As an adolescent, his works were often performed at home with a private orchestra for the associates of his wealthy parents amongst the intellectual elite of Berlin. Between the ages of 12 and 14, Mendelssohn wrote 12 string symphonies for such concerts, and a number of chamber works. His first work, a piano quartet, was published when he was 13. It was probably Abraham Mendelssohn who procured the publication of this quartet by the house of Schlesinger. In 1824 the 15-year-old wrote his first symphony for full orchestra (in C minor, Op. 11).  At age 16 Mendelssohn wrote his String Octet in E-flat major, a work which has been regarded as "mark[ing] the beginning of his maturity as a composer." This Octet and his Overture to Shakespeare's

Meeting Goethe and conducting Bach.

In 1821 Zelter introduced Mendelssohn to his friend and correspondent Johann Wolfgang von Goethe (then in his seventies), who was greatly impressed by the child, leading to perhaps the earliest confirmed comparison with Mozart in the following conversation between Goethe and Zelter:  Mendelssohn was invited to meet Goethe on several later occasions, and set a number of Goethe's poems to music. His other compositions inspired by Goethe include the overture "Calm Sea and Prosperous Voyage" (Op. 27, 1828), and the cantata "Die erste Walpurgisnacht" ("The First Walpurgis Night", Op. 60, 1832).  In 1829, with the backing of Zelter and the assistance of the actor Eduard Devrient, Mendelssohn arranged and conducted a performance in Berlin of Bach's "St Matthew Passion". Four

Düsseldorf.

On Zelter's death in 1832, Mendelssohn had hopes of succeeding him as conductor of the Singakademie; but at a vote in January 1833 he was defeated for the post by Carl Friedrich Rungenhagen. This may have been because of Mendelssohn's youth, and fear of possible innovations; it was also suspected by some to be attributable to his Jewish ancestry. Following this rebuff, Mendelssohn divided most of his professional time over the next few years between Britain and Düsseldorf, where he was appointed musical director (his first paid post as a musician) in 1833.  In the spring of that year Mendelssohn directed the Lower Rhenish Music Festival

Leipzig and Berlin.

In Leipzig, Mendelssohn concentrated on developing the town's musical life by working with the orchestra, the opera house, the Thomanerchor (of which Bach had been a director), and the city's other choral and musical institutions. Mendelssohn's concerts included, in addition to many of his own works, three series of "historical concerts" featuring music of the eighteenth century, and a number of works by his contemporaries. He was deluged by offers of music from rising and would-be composers; among these was Richard Wagner, who submitted his early Symphony, the score of which, to Wagner's disgust, Mendelssohn lost or mislaid. Mendelssohn also revived interest in the music of Franz Schubert. Robert Schumann discovered the manuscript of Schubert's Ninth Symphony and sent it to Mendelssohn, who promptly premiered it in Leipzig on 21 March 1839, more than a decade after Schubert's death.  A landmark event during Mendelssohn's Leipzig years was the premiere of his oratorio "Paulus", (the English version of this is known as "St. Paul"), given at the Lower Rhenish Festival in Düsseldorf in 1836, shortly after the death

Mendelssohn in Britain.

Mendelssohn first visited Britain in 1829, where Moscheles, who had already settled in London, introduced him to influential musical circles. In the summer he visited Edinburgh, where he met among others the composer John Thomson, whom he later recommended for the post of Professor of Music at Edinburgh University. He made ten visits to Britain, lasting about 20 months; he won a strong following, which enabled him to make a good impression on British musical life. He composed and performed, and also edited for British publishers the first critical editions of oratorios of Handel and of the organ music of J. S. Bach. Scotland inspired two of his most famous works: the overture "The Hebrides" (also known as "Fingal's Cave"); and the "Scottish Symphony" (Symphony No. 3). An English Heritage blue plaque commemorating Mendelssohn's residence in London was placed at 4 Hobart Place in Belgravia, London, in 2013.  His

Death.

Mendelssohn suffered from poor health in the final years of his life, probably aggravated by nervous problems and overwork. A final tour of England left him exhausted and ill, and the death of his sister, Fanny, on 14 May 1847, caused him further distress. Less than six months later, on 4 November, aged 38, Mendelssohn died in Leipzig after a series of strokes. His grandfather Moses, Fanny, and both his parents had all died from similar apoplexies. Felix's funeral was held at the Paulinerkirche, Leipzig, and he was buried at the Dreifaltigkeitsfriedhof I in Berlin-Kreuzberg. The pallbearers included Moscheles, Schumann and Niels Gade. Mendelssohn had once described death, in a letter to a stranger, as a place "where it is to be hoped there is still music, but no more sorrow or partings."

Personal life.

Personality.

While Mendelssohn was often presented as equable, happy, and placid in temperament, particularly in the detailed family memoirs published by his nephew Sebastian Hensel after the composer's death, this was misleading. The music historian R. Larry Todd notes "the remarkable process of idealization" of Mendelssohn's character "that crystallized in the memoirs of the composer's circle", including Hensel's. The nickname "discontented Polish count" was given to Mendelssohn on account of his aloofness, and he referred to the epithet in his letters. He was frequently given to fits

Religion.

On 21 March 1816, at the age of seven years, Mendelssohn was baptised with his brother and sisters in a home ceremony by Johann Jakob Stegemann, minister of the Evangelical congregation of Berlin's Jerusalem Church and New Church. Although Mendelssohn was a conforming Christian as a member of the Reformed Church, he was both conscious and proud of his Jewish ancestry and notably of his connection with his grandfather, Moses Mendelssohn. He was the prime mover in proposing to the publisher Heinrich Brockhaus a complete edition of Moses's works, which continued with the support

Mendelssohn and his contemporaries.

Throughout his life Mendelssohn was wary of the more radical musical developments undertaken by some of his contemporaries. He was generally on friendly, if sometimes somewhat cool, terms with Hector Berlioz, Franz Liszt, and Giacomo Meyerbeer, but in his letters expresses his frank disapproval of their works, for example writing of Liszt that his compositions were "inferior to his playing, and [...] only calculated for virtuosos"; of Berlioz's overture "Les francs-juges" "[T]he orchestration is such a frightful muddle [...] that one ought to wash one's hands after handling one of his scores"; and of

Marriage and children.

Mendelssohn married Cécile Charlotte Sophie Jeanrenaud (10 October 1817 – 25 September 1853), the daughter of a French Reformed Church clergyman, on 28 March 1837. The couple had five children: Carl, Marie, Paul, Lili and Felix August. The second youngest child, Felix August, contracted measles in 1844 and was left with impaired health; he died in 1851. The eldest, Carl Mendelssohn Bartholdy (7 February 1838 – 23 February 1897), became

Jenny Lind.

Mendelssohn became close to the Swedish soprano Jenny Lind, whom he met in October 1844. Papers confirming their relationship had not been made public. In 2013, George Biddlecombe confirmed in the "Journal of the Royal Musical Association" that "The Committee of the Mendelssohn Scholarship Foundation possesses material indicating that Mendelssohn wrote passionate love letters to Jenny Lind entreating her to join him in an adulterous relationship and threatening suicide as a means of exerting pressure upon her, and that these letters were destroyed on being discovered after her death."  Mendelssohn met and worked with Lind many times, and started an opera, "Lorelei", for her, based on the legend of the Lorelei Rhine maidens; the opera was unfinished at his death. He is said to have tailored the aria "Hear Ye Israel", in

Music.

Composer.

Style.

Something of Mendelssohn's intense attachment to his personal vision of music is conveyed in his comments to a correspondent who suggested converting some of the "Songs Without Words" into lieder by adding texts: "What [the] music I love expresses to me, are not thoughts that are too "indefinite" for me to put into words, but on the contrary, too "definite"."  Schumann wrote of Mendelssohn that he was "the Mozart of the nineteenth century, the most brilliant musician, the one who most clearly sees through the contradictions of the age and for the first time reconciles them." This appreciation brings to the fore two

Early works.

The young Mendelssohn was greatly influenced in his childhood by the music of both J. S. Bach and C. P. E. Bach, and of Beethoven, Joseph Haydn and Mozart; traces of these composers can be seen in the 12 early string symphonies. These were written from 1821 to 1823, when he was between the ages of 12 and 14, principally for performance in the Mendelssohn household, and not published or publicly performed until long after his death.  His first published works were his three piano quartets (1822–1825; Op. 1 in C minor, Op. 2 in F minor and Op. 3

Symphonies.

Mendelssohn's mature symphonies are numbered approximately in the order of publication, rather than the order in which they were composed. The order of composition is: 1, 5, 4, 2, 3. The placement of No. 3 in this sequence is problematic because he worked on it for over a decade, starting the sketches soon after he began work on No. 5 but completing it after both Nos. 5 and 4.  The Symphony No. 1 in C minor for full orchestra was written in 1824, when Mendelssohn was aged 15. This work is experimental, showing the influences of Beethoven and Carl Maria von Weber. Mendelssohn conducted the symphony on his first visit to London in 1829, with the orchestra of the Philharmonic Society. For the third movement he substituted an orchestration of the Scherzo from his Octet. In this form

Other orchestral music.

Mendelssohn wrote the concert overture "The Hebrides" ("Fingal's Cave") in 1830, inspired by visits to Scotland around the end of the 1820s. He visited Fingal's Cave, on the Hebridean isle of Staffa, as part of his Grand Tour of Europe, and was so impressed that he scribbled the opening theme of the overture on the spot, including it in a letter he wrote home the same

Concertos.

The Violin Concerto in E minor, Op. 64 (1844), was written for Ferdinand David. David, who had worked closely with Mendelssohn during the piece's preparation, gave the premiere of the concerto on his Guarneri violin. Joseph Joachim called it one of the four great violin concertos along with those of Beethoven, Brahms, and Bruch.  Mendelssohn also wrote a lesser-known, early concerto for violin and strings in D minor (1822); four piano concertos ("no. 0"

Chamber music.

Mendelssohn's mature output contains numerous chamber works, many of which display an emotional intensity lacking in some of his larger works. In particular, his String Quartet No. 6, the last of his string quartets and his last major work – written following the death of his

Piano music.

The musicologist Glenn Stanley observes that "[u]nlike Brahms, unlike his contemporaries Schumann, Chopin and Liszt, and unlike [his] revered past masters...Mendelssohn did not regard the piano as a preferred medium for his most significant artistic statements". Mendelssohn's "Songs Without Words" ("Lieder ohne Worte"), eight cycles each containing six lyric pieces (two published posthumously), remain his most famous solo piano compositions. They became standard parlour recital items even during the composer's lifetime, and their overwhelming popularity,

Organ music.

Mendelssohn played and composed for organ from the age of 11 until his death. His primary organ works are the "Three Preludes

Opera.

Mendelssohn wrote some Singspiele for family performance in his youth. His opera "Die beiden Neffen" ("The Two Nephews") was rehearsed for him on his 15th birthday. 1829 saw "Die Heimkehr aus der Fremde" ("Son and Stranger" or "Return of the Roamer"), a comedy of mistaken identity written in honour of his parents' silver anniversary and unpublished during his lifetime. In 1825 he wrote a more sophisticated work, "Die Hochzeit des Camacho" ("Camacho's Wedding"), based on an episode in "Don Quixote", for public consumption. It was produced in Berlin in

Choral works.

Mendelssohn's two large biblical oratorios, "St Paul" in 1836 and "Elijah" in 1846, are greatly influenced by J. S. Bach. The surviving fragments of an unfinished oratorio, "Christus", consist of a recitative, a chorus "There Shall a Star Come out of Jacob", and a male voice trio.  Strikingly different is the more overtly Romantic "Die erste Walpurgisnacht" ("The First Walpurgis Night"), a setting for chorus and orchestra of a ballad by Goethe describing pagan rituals of the Druids in the Harz mountains in the early days of Christianity. This score has been seen by the scholar Heinz-Klaus Metzger as a "Jewish protest against the domination of Christianity".  Mendelssohn wrote five settings from "The Book of Psalms" for chorus and orchestra. Schumann opined

Songs.

Mendelssohn wrote many songs, both for solo voice and for duet, with piano. It has been asserted that from 1819 (when he was 10) until his death there was "scarcely a single month in which he was not occupied with song composition". Many of these songs are simple, or slightly modified, strophic settings. Some, such as his best-known song "Auf Flügeln des Gesanges" ("On Wings of Song"), became popular. The scholar Susan Youens comments "If [Mendelssohn]'s emotional range in lied was narrower than Schubert's, that is hardly surprising: Schubert composed many more songs than Mendelssohn across a wider spectrum", and whilst Schubert had a declared intent to modernize the song style of his day, "[t]his was not Mendelssohn's mission."  A number of songs written by Mendelssohn's sister Fanny originally appeared under her brother's name; this may have been partly due to the prejudice of the family, and partly to her own retiring nature.

Performer.

During his lifetime, Mendelssohn became renowned as a keyboard performer, both on the piano and organ. One of his obituarists noted: "First and chiefest we esteem his pianoforte-playing, with its amazing elasticity of touch, rapidity, and power; next his scientific and vigorous organ playing [...] his triumphs on these instruments are fresh in public recollection. In his concerts and recitals Mendelssohn performed works by some of his German predecessors, notably Carl Maria von Weber,

Conductor.

Mendelssohn was a noted conductor, both of his own works and of those by other composers. At his London debut in 1829, he was noted for his innovatory use of a baton (then a great novelty). But his novelty also extended to taking great care over tempo, dynamics and the orchestral players themselves – both rebuking them when they were recalcitrant and praising them when they satisfied him. It was his success while conducting at the Lower Rhine music festival of 1836 that led to

Editor.

Mendelssohn's interest in baroque music was not limited to the Bach "St Matthew Passion" which he had revived in 1829. He was concerned in preparing and editing such music, whether for performance or for publication, to be as close as possible to the original intentions of the composers, including wherever possible a

Teacher.

Although Mendelssohn attributed great importance to musical education, and made a substantial commitment to the Conservatoire he founded in Leipzig, he did not greatly enjoy teaching and took only a very

Reputation and legacy.

The first century.

In the immediate wake of Mendelssohn's death, he was mourned both in Germany and England. However, the conservative strain in Mendelssohn, which set him apart from some of his more flamboyant contemporaries, bred a corollary condescension amongst some of them toward his music. Mendelssohn's relations with Berlioz, Liszt and others had been uneasy and equivocal. Listeners who had raised questions about Mendelssohn's talent included Heinrich Heine, who wrote in 1836 after hearing the oratorio "St. Paul" that his work was  characterized by a great, strict, very serious seriousness, a determined, almost importunate tendency to follow classical models, the finest, cleverest calculation, sharp intelligence and, finally, complete lack of naïveté. But is there in art any originality of genius without naïveté?  Such criticism of Mendelssohn for his very ability

Modern opinions.

Appreciation of Mendelssohn's work has developed over the last 50 years, together with the publication of a number of biographies placing his achievements in context. Mercer-Taylor comments on the irony that "this broad-based reevaluation of Mendelssohn's music is made possible, in part, by a general disintegration of the idea of a musical canon", an idea which Mendelssohn "as a conductor, pianist and scholar" had done so much to establish. The critic H. L. Mencken concluded that, if Mendelssohn indeed missed true greatness, he missed it "by a hair".  Charles Rosen, in a chapter on Mendelssohn in his 1995 book "The Romantic Generation", both praises and criticizes the composer. He calls him "the greatest child prodigy the history of Western music has ever known", whose command at age 16 surpassed that of Mozart or Chopin at 19, the possessor at an early age of a "control of large-scale structure unsurpassed by any composer of his generation", and a "genius" with a "profound" comprehension of Beethoven. Rosen believes that in the composer's later years, without

Notes and references.

Further reading.

There are numerous published editions and selections of Mendelssohn's letters.  The main collections of Mendelssohn's original musical autographs and letters are to

External links.

Recordings.

"See articles on

Jakob Ludwig Felix Mendelssohn Bartholdy (3 February 18094 November 1847), born and widely known as Felix Mendelssohn, was a German composer, pianist, organist and conductor of the early Romantic period. Mendelssohn's compositions include symphonies, concertos, piano music and chamber music. His best-known works include his overture and incidental music for "A Midsummer Night's Dream", the "Italian Symphony", the "Scottish Symphony", the oratorio "Elijah", the overture "The Hebrides", his mature Violin Concerto, and his String Octet. The melody for the Christmas carol "Hark! The Herald Angels Sing" is also his. Mendelssohn's "Songs Without Words" are his most famous solo piano compositions.

Jakob Ludwig Felix Mendelssohn Bartholdy (3. února 1809, Hamburk – 4. listopadu 1847, Lipsko) byl jeden z nejvýznamnějších německých romantických hudebních skladatelů.


Etymology.

The word "porcupine" comes from the middle or old French word "porcespin", which means thorn pig. Its roots derive from the Latin words "porcus" or pig and "spina" meaning thorns. Other colloquial names for the animal include quill pig. It is also referred to as the Canadian porcupine or common porcupine. The porcupine's scientific name, "Erethizon dorsatum", can be loosely translated as "the animal with the irritating back". Several Native American names exist, such as the Lakota name "pahin" meaning quill and the Chipewyan name "ts'l".

Taxonomy and evolution.

The North American porcupine migrated from South America, where all New World porcupines or hystricomorphs evolved. "Erethizon" appeared in North America shortly after the two continents joined together in the later Tertiary period. Other hystricomorphs also migrated, but "Erethizon" was the only one to survive north of Mexico. No known fossils are attributed to hystricomorphs prior to the late Tertiary period. Some fossils, such as species from the family Paramyidae, show resemblance to the porcupine, but they are so primitive and generalized that they could be ancestors to all later rodents.  South American hystricomorphs first appeared in the Lower Oligocene period. They are thought to have migrated from Africa, ancestors of the Old World porcupines or Hystricidae or they originated based on a migration of the North American Paramyidae.  The earliest appearance of "E. dorsatum" is from the Pleistocene era found along the Arroyo del Cedazo near Aguascalientes, Mexico.

Subspecies.

Seven subspecies of "E. dorsatum" are recognized. They are subdivided by different ranges across North America. By far the most common is "E. d. dorsatum", which ranges from Nova Scotia to Alberta and from Virginia to the Yukon. "E. d. picinum" occupies a small range in northeastern Quebec and Labrador. "E. d. couesi" is the most southern ranging from northern Mexico to Colorado. "E. d. bruneri" can be found in the midwest from Arkansas to Montana. The last three are found in the west. From south to north they are "E.d. epixanthum", "E. d. nigrescens", and "E. d. myops".

Description.

Porcupines are usually dark brown or black in color, with white highlights. They have a stocky body, a small face, short legs, and a short, thick tail. This species is the largest of the New World porcupines and is one of the largest North American rodents, second only to the American beaver in size. The head-and-body length is, not counting a tail of. The hind foot length is. Weight can range from. Weight in adult females can average some while 5 wild-caught males averaged.  The porcupine is the only native North American mammal with antibiotics in its skin. Those antibiotics prevent infection when a porcupine falls out of a tree and is stuck with its own quills upon hitting the ground. Porcupines fall out of trees fairly often because they are highly tempted by the succulent buds and twigs at the ends of the branches. The porcupine, the wolverine, and the skunk are the only North American mammals that have strongly contrasting black-and-white coloration, because they are the only mammals that benefit from letting other animals know where and what they are in the dark of night.

Quills.

The most distinguishing feature of the porcupine is its coat of quills. An adult porcupine has about 30,000 quills that cover all of its body except its underbelly, face, and feet. Quills are modified hairs formed into sharp, barbed, hollow spines. They are used primarily for defense, but also serve to insulate their bodies during winter. Porcupines do not throw their quills, but when threatened, they contract the muscles near the skin, which causes the quills to stand up and out from their bodies. When the quills are in this position, they become easier to detach from the body, especially when a porcupine swings its tail toward an attacker. The barbs at the tail tip become lodged in the flesh of an attacker and are difficult and painful to remove. The quills are normally flattened against the body and in this position are less easily dislodged.

Stench.

The North American porcupine has a strong odor to warn away predators, which it can increase when agitated. The smell has been described as similar to strong human body odor, goats, or some cheeses. The odor is generated by a patch of skin called the rosette, on the lower back where modified quills serve as osmetrichia to broadcast the smell. The characteristic odor comes from the R-enantiomer of delta-decalactone. Not present is the S-enantiomer which smells like coconut and is used in flavorings and perfumes.

Distribution and habitat.

North American porcupines range from Canada, Alaska, and into northern Mexico. They are commonly found in coniferous and mixed forested areas, but have adapted to harsh environments such as shrublands, tundra, and deserts. They make their dens in hollow trees or in rocky areas.

Ecology.

Diet.

During the summer, they eat twigs, roots, stems, berries, and other vegetation. In the winter, they mainly eat conifer needles and tree bark. Porcupines are selective in their eating; for example out of every 1,000 trees in the Catskill Mountains, porcupines will only eat from 1-2 linden trees and one big toothed aspen.

Behavior.

Porcupines are nearsighted and slow-moving. They are mainly active at night (nocturnal); on summer days, they often rest in trees. They do not hibernate, but sleep in and stay close to their dens in winter. The strength of the porcupine's defense has given it the ability to live a solitary life, unlike many herbivores, which must move in flocks or herds. Consequently, the porcupine has "an extraordinary ability to learn complex mazes and to remember them as much as a hundred days afterward".

Defense.

The North American porcupine has specific behaviors to warn or defend against predators. The defense strategy is based on aposematism in several modalities. It has a strong warning odor which it can increase when agitated. When threatened, an adult porcupine can bristle its quills, displaying a white stripe down its back, and use its teeth to make a warning, clacking sound. If the olfactory, visual, and auditory warnings fail, then it can rely on its quills. An adult porcupine when attacked turns its rear to the predator. When approached, the porcupine can swing its tail at an attacker's face. Despite popular myth, the porcupine does not throw its quills. Instead, when a quill comes in contact with the attacker, it can easily penetrate and become embedded in its skin. Each quill contains microscopic barbs which allow it to stick into the flesh of an attacker. This strategy is successful against most attacks. With a face full of quills, an attacking creature often retreats. The porcupine's last line of defense is to climb a tree.

Predators.

Natural predators of this species include fishers (a cat-sized mustelid), wolverines, coyotes, wolves, American black bears, and cougars, as well as humans. The only known avian predators of this species are golden eagles and great horned owls. In many cases, injury or even death may occur in the predator from embedded porcupine quills even if they are successful in dispatching the porcupine.  The North American porcupine is most at risk from the fisher ("Martes pennanti"). Fishers are related to the weasel, with males sometimes exceeding a mass of. Fishers have two advantages that make them capable hunters of the porcupine. First, they are agile tree climbers. If a fisher locates a porcupine, it cannot hide by fleeing into a tree because the fisher can pursue it and force it down to the ground. A porcupine can sometimes defend itself by facing the trunk on a branch and presenting its tail to the fisher. If the fisher manages to force a porcupine down to the ground, the porcupine will try to present its hindquarters and tail to the attacker, but the fisher is quick and agile. As it circles the porcupine, every chance it gets, it bites the face. After repeated attacks, the porcupine eventually weakens, allowing the fisher to flip the porcupine over and rip open the porcupine's underbelly, thus killing it. The fisher will then consume the porcupine through the chest and abdomen, avoiding the quills. One study suggested that since male fishers are considerably larger than females (often weighing on average twice as much), only males are likely to hunt porcupines. It appears that female fishers usually favor prey such as snowshoe hares.  Another effective predator is the cougar. It does not bother with quill avoidance, but tolerates them. Some individuals have been found with dozens of quills embedded in their gums to no ill effect. It can climb trees, so its favorite method is to position itself below the porcupine and knock it to the ground, where it is quickly dispatched. Other predators, such as canids, may attack but do not pose much of a threat. In some parts of the Great Basin, cougars have greatly decreased numbers of porcupines in mountainous forests through predation. However, in some cases porcupine quills have indeed killed cougars, although usually this is after the cougar has already consumed the porcupine.

Reproduction.

Female porcupines are solitary for most of the year except during the fall when breeding season begins. At this time, they secrete a thick mucus which mixes with their urine. The resulting odor attracts males in the vicinity. Males that approach a female do not automatically begin mating. The first male that comes along typically sits in the same tree below a female. If another male approaches, he may fight for the right to mate. Once a dominant male is successful, he approaches the female and uses a spray of his urine on the female. Only a few drops touch the female, but the chemical reaction allows the female to fully enter estrus. Once this is accomplished high in the tree, the mating process takes place on the ground. When porcupines are mating, they tighten their skin and hold their quills flat, so as not to injure each other. Mating may occur repeatedly until the female loses interest and climbs back into the tree.  The North American porcupine has a long gestation period relative to other rodents. The female's pregnancy lasts for 202 days. By contrast, the North American beaver, which is comparable in size, has a gestation period of 128 days. The eastern grey squirrel ("Sciurus carolinensis") has a gestation period of just 44 days. Porcupines give birth to a single young. At birth, they weigh about 450 g, which increases to nearly 1 kg after the first two weeks. They do not gain full adult weight until the end of the second summer about 4.5 kg. Their quills harden soon after birth.  Female porcupines provide all parental care. For the first two weeks, the young rely on their mother for sustenance. After this, they learn to climb trees and start to forage. They continue to nurse for up to four months, which coincides with the fall mating season. They stay close to their mothers. Mother porcupines do not defend their young, but have been known to care for them even after death. In one case, when a baby had fallen to its death from a tree, the mother came down and stayed by her baby's side for hours waiting vainly for the baby to revive.

Life expectancy.

North American porcupines have a relatively long life expectancy. Some individuals have been found to live up to 30 years of age. Common causes of mortality include predation and starvation. Porcupines can also die from falling out of a tree. They are also killed by motor vehicles.

Porcupines and humans.

They are considered by some to be a pest because of the damage that they often inflict on trees and wooden and leather objects. Plywood is especially vulnerable because of the salts added during manufacture. The quills are used by Native Americans to decorate articles such as baskets and clothing. Porcupines are edible and were an important source of food, especially in winter, to the native peoples of Canada's boreal forests. They move slowly (having few threats in its natural environment which would give it the need to flee quickly) and are often hit by vehicles while crossing roads.  Porcupines are infamous among backpackers and backpacking publications for their love of salt. More specifically, for eating road salt covered boots left outside of tents overnight. They have a similar reputation among forestry workers of all types for trying to eat their sweat soaked (and thus salty) gloves and the similarly sweat covered wood handles on tools.

Conservation status.

Globally, the North American porcupine is listed as a species of least concern. It is common throughout its range except in some U.S. states in the southeast part of its range. For example, it is listed as a species in need of conservation in Maryland. As of 1999, 15 remnant populations remain scattered throughout north-central Mexico. They live in riparian forests, mesquite scrubland, grasslands, and thorn forests. They are threatened by hunting and habitat loss. As of 1994, it was listed as an endangered species in Mexico.

The North American porcupine ("Erethizon dorsatum"), also known as the Canadian porcupine or common porcupine, is a large rodent in the New World porcupine family. The beaver is the only rodent in North America that is larger than the North American porcupine. The porcupine is a caviomorph rodent whose ancestors rafted across the Atlantic from Africa to Brazil over 40 million years ago, and then migrated to North America during the Great American Interchange after the Isthmus of Panama rose 3 million years ago.

Urzon kanadský ("Erethizon dorsatum") je severoamerický hlodavec. Vzhledem připomíná dikobraza, s nímž bývá laiky zaměňován. Na rozdíl od něj má kratší a měkčí ostny a dovede šplhat po stromech.


Description.

The bulk of a zipper consists of two rows of protruding teeth, which may be made to interdigitate, linking the rows, carrying from tens to hundreds of specially shaped metal or plastic teeth. These teeth can be either individual or shaped from a continuous coil, and are also referred to as "elements". The slider, operated by hand, moves along the rows of teeth. Inside the slider is a Y-shaped channel that meshes together or separates the opposing rows of teeth, depending on the direction of the slider's movement. The word "zipper" is onomatopoetic, because it was named for the sound the device makes when used, a high-pitched "zip."  In many jackets and similar garments, the opening is closed completely when the slider is at the top end. Some jackets have double-separating zippers with two sliders on the tape. When the sliders are on opposite ends of the tape, the jacket is closed. If the lower slider is raised then the bottom part of the jacket may be opened to allow more comfortable sitting or bicycling. When both sliders are lowered then the zipper may be totally separated.  Bags, suitcases and other pieces of luggage also often feature two sliders on the tape: the part of the zipper between them is unfastened. When the two sliders are located next to each other, which can be at any point along the tape, the zipper is fully closed.  Zippers may:  These variations are achieved by sewing one end of the zipper together, sewing both ends together, or allowing both ends of the zipper to fall completely apart.  A zipper costs relatively little, but if it fails, the garment may be unusable until the zipper is repaired or replaced—which can be quite difficult and expensive. Problems often lie with the zipper slider; when it becomes worn it does not properly align and join the alternating teeth. With separating zippers, the insertion pin may tear loose from the tape; the tape may even disintegrate from use. If a zipper fails, it can either jam (i.e. get stuck) or partially break off.

History.

In 1851, Elias Howe received a patent for an "Automatic, Continuous Clothing Closure". He did not try seriously to market it, missing recognition he might otherwise have received. Howe's device was more like an elaborate drawstring than a true slide fastener.  Forty-two years later, in 1891, Whitcomb Judson, who invented a pneumatic street railway, marketed a "Clasp Locker". The device served as a (more complicated) hook-and-eye shoe fastener. With the support of businessman Colonel Lewis Walker, Judson launched the Universal Fastener Company to manufacture the new device. The clasp locker had its public debut at the 1893 Chicago World's Fair and met with little commercial success. Judson is sometimes given credit as the inventor of the zipper, but he never made a practical device.  The Universal Fastener Company moved to Hoboken, New Jersey, in 1901, reorganized as the Fastener Manufacturing and Machine Company. Gideon Sundback, a Swedish-American electrical engineer, was hired to work for the company in 1906. Good technical skills and a marriage to the plant-manager's daughter Elvira Aronson led Sundback to the position of head designer. The company moved to Meadville, Pennsylvania, where it operated for most of the 20th century under the name Talon, Inc. Sundback worked on improving the fastener and in 1909 he registered a patent in Germany. The US rights to this invention were in the name of the Meadville company (operating as the Hookless Fastener Co.), but Sundback retained non-U.S. rights and used these to set up in subsequent years Lightning Fastner Co. in St. Catharines, Ontario. Sundback's work with this firm has led to the common misperception that he was Canadian and that the zipper originated in that country.  Gideon Sundback increased the number of fastening elements from four per inch (about one every 6.4 mm) to ten or eleven (around every 2.5 mm), introduced two facing rows of teeth that pulled into a single piece by the slider, and increased the opening for the teeth guided by the slider. The patent for the "Separable Fastener" was issued in 1917. Gideon Sundback also created the manufacturing machine for the new device. The "S-L" or "scrapless" machine took a special Y-shaped wire and cut scoops from it, then punched the scoop dimple and nib, and clamped each scoop on a cloth tape to produce a continuous zipper chain. Within the first year of operation, Sundback's machinery was producing a few hundred feet (around 100 meters) of fastener per day. In March of the same year, Mathieu Burri, a Swiss inventor, improved the design by adding a lock-in system attached to the last teeth, but his version never got into production due to conflicting patents.  In 1923 during a trip to Europe Sundback sold his European rights to Martin Othmar Winterhalter who improved the design by using ribs and grooves instead of Sundback's joints and jaws and started producing with his company Riri on a large scale first in Germany, then in Switzerland. The popular North American term "zipper", (UK "zip", or occasionally "zip-fastener"), came from the B. F. Goodrich Company in 1923. The company opted to use Gideon Sundback's fastener on a new type of rubber boots (or galoshes) and referred to it as the zipper, and the name stuck. The two chief uses of the zipper in its early years were for closing boots and tobacco pouches. Zippers began being used for clothing in 1925 by Schott Bros. on leather jackets.  In the 1930s, a sales campaign began for children's clothing featuring zippers. The campaign praised zippers for promoting self-reliance in young children by making it possible for them to dress in self-help clothing. The zipper beat the button in 1937 in the "Battle of the Fly", after French fashion designers raved over zippers in men's trousers. "Esquire" declared the zipper the "Newest Tailoring Idea for Men" and among the zippered fly's many virtues was that it would exclude "The Possibility of Unintentional and Embarrassing Disarray."  The most recent innovation in the zipper's design was the introduction of models that could open on both ends, as on jackets. Today the zipper is by far the most widespread fastener, and is used on clothing, luggage, leather goods, and various other objects.

Types.

Air and water tightness.

Airtight zippers were first developed by NASA for making high-altitude pressure suits and later space suits, capable of retaining air pressure inside the suit in the vacuum of space.  The airtight zipper is built like a standard toothed zipper, but with a waterproof sheeting (which is made of fabric-reinforced polyethylene and is bonded to the rest of the suit) wrapped around the outside of each row of zipper teeth. When the zipper is closed, the two facing sides of the plastic sheeting are squeezed tightly against one another (between the C-shaped clips) both above and below the zipper teeth, forming a double seal.  This double-mated surface is good at retaining both vacuum and pressure, but the fit must be very tight, to press the surfaces together firmly. Consequently, these zippers are typically very stiff when zipped shut and have minimal flex or stretch. They are hard to open and close because the zipper anvil must bend apart teeth that are being held under tension. They can also be derailed (and damage the sealing surfaces) if the teeth are misaligned while straining to pull the zipper shut.  For waterproof and airtight applications one can differentiate between the following three main zipper types:

water- & airtight zippers.

In general, the zippers have a right and left pair of fastener tapes in which element rows (teeth, coil) are formed. In such a waterproof & airtight zippers are coupled with each other such that facing side edge parts of the right and left waterproof tapes are in close contact with each other, which prevents water from entering into the tape back surface side from the tape top surface side (or into the tape top surface side from the tape back surface side) via a gap between the right and left waterproof tapes. The water- & airtight zippers includes at least one slider and a slider stopper elements (bottom stop, docking end, pin-box).

splash-proof zippers.

The waterproof- and airtight zippers are very common where sophisticated requirements has to be covered, such as on

water-resistant zip-lock & magnetic zippers.

A less common water-resistant zipper is includes a molded plastic ridge seal similar to the mating surfaces on a ziploc bag. Such a zipper is easier to open and close than a clipped version, and the slider has a gap above the zipper teeth for separating the ridge seal. This seal is structurally weak against internal pressure (cross tension stability), and can be separated by pressure within the sealed container pushing outward on the ridges, which simply flex and spread apart, potentially allowing air or liquid entry through the spread-open ridges. Ridge-sealed zippers are sometimes used on lower-cost products.

Anti-slide zipper locks.

Some zippers include a designed ability for the slider to hold in a steady open or closed position, resisting forces that would try to move the slider and open the zipper unexpectedly. There are two common ways this is accomplished:  The zipper handle can have a short protruding pin stamped into it, which inserts between the zipper teeth through a hole on the slider, when the handle is folded down flat against the zipper teeth. This appears on some brands of trousers. The handle of the fly zipper is folded flat against the teeth when it is not in use, and the handle is held down by both slider hinge tension and the fabric flap over the fly.  The slider can also have a two-piece hinge assembly attaching the handle to the slider, with the base of the hinge under spring tension and with protruding pins on the bottom that insert between the zipper teeth. To move the zipper, the handle is pulled outward against spring tension, lifting the pins out from between the teeth as the slider moves. When the handle is released the pins automatically engage between the zipper teeth again. They are called "auto-lock sliders".  A three-piece version of the above uses a tiny pivoting arm held under tension inside the hinge. Pulling on the handle from any direction lifts the pivoting arm's pins out of the zipper teeth so that the slider can move.

Components.

The components of a zipper are:

Manufacturing.

Forbes reported in 2003 that although the zipper market in the 1960s was dominated by Talon Zipper (USA) and Optilon (Germany), Japanese manufacturer YKK grew to become the industry giant by the 1980s. YKK held 45 percent of world market share, followed by Optilon (8 percent) and Talon Zipper (7 percent).  Indian Tex Corp has also emerged as a significant supplier to the apparel industry.  In Europe, Cremalleras Rubi company established in 1926 in Spain, continues to compete with the big multinationals selling over 30 million zippers in 2012.  In 2005, "The Guardian" reported that China had 80 percent of the international market. Most of its product is made in Qiaotou, Yongjia County.

Mechanism.

From, the following mechanism of the zipper improved by Gideon Sundback in 1917 is explained:  The zipper is analogous in function to a drawstring, but different in mechanism. A draw string works by tension in the string drawing together the eyelets of the piece together because the tension acts to straighten the string and so forces the eyelets toward a line. The zipper works by an elastic, that is, reversible, deformation of the "locking members" (teeth). The zipper teeth are shaped and sized so that the forces which act on the zipper when the garment it is sewn on is worn cannot unlock the teeth. The slider constrains the teeth positions, moves them along a given path, and acts on the teeth one-by-one in its "Y-shaped channel" and so can reversibly lock and unlock them. This is a lock and key design. In Sundback's invention the teeth are symmetric with "exterior and interior rounded surfaces" that are "elongated transversely". The teeth have a material part ("external projection") and a space ("internal recess"). The material part of one tooth is slightly smaller than the space on the other and so shaped to act as a "contractible jaw"--the jaw is elastically opened and then closed as it goes over the other tooth. The "snug fit" that results when "one member nests within the recess of an adjoining member" is a stable locked state. The maximum force when the slider operates is in between the unlocked and locked positions, giving two stable mechanical equilibria. The "snug fit" is stable not only to forces from wear that act in the same direction as those of the slider but to transverse and longitudinal (both perpendicular) forces.  The zipper is analogous in mechanism to a bobby pin, where the person's hand slides hair into and out of the pin's "contractible jaw".

In popular culture.

Zippers have entered into urban legends. American folklorist Jan Brunvand noted that "The zipper has been the subject of jokes and legends since... the 1920s". Those stories reflect "modern anxieties and desires", emphasizing embarrassments and accidents, primarily involving the flies of men's trousers in stories such as "The Unzipped Stranger" and "The Unzipped Fly".

Durability and repairs.

The zipper is often the least durable component in any garment or type of equipment. Most often the zipper fails to close due to a worn or bent slider not being able to apply the necessary force to the sides of the teeth to cause them to interlock. This problem can sometimes be redressed by using small pliers to carefully squeeze the back part of the slider together a fraction of a millimeter. This can compensate for the wear of the slider. The slider is typically made as a magnesium diecast which breaks easily. It is necessary to reduce the force on the pliers before it can be felt that the slider actually gives in. If it is not yet possible to successfully close the zipper, the pressure applied to the slider should only gradually be increased. Another way to reduce the gap of the open end of the slider is by preparing a small block of wood by sawing a slot into one end so that it fits over the upper arm of the slider. Then a hammer can be used to exact a force onto the slider by carefully hitting the wood.  When the protective coating of the diecast slider has been worn off by prolonged usage, the material can corrode. The corrosion products are usually metal salts which can accumulate and block the slider from moving. When this happens the salt can often be dissolved by submerging the slider in vinegar or another mild acid. Otherwise the slider needs to be removed and replaced.

References.

A zipper, zip, fly, dingy, or zip fastener, formerly known as a clasp lock/locker, is a commonly used device for binding the edges of an opening of fabric or other flexible material, such as on a garment or a bag. It is used in clothing (e.g., jackets and jeans), luggage and other bags, sporting goods, camping gear (e.g. tents and sleeping bags), and other items. Zippers come in all different sizes, shapes, and colors. Whitcomb L. Judson, who was an American inventor from Chicago, is sometimes given credit as the inventor of the zipper, but he never made a practical device. The method, still in use today, is based on interlocking teeth. Initially, it was titled the "hookless fastener" and was later redesigned to become more reliable.

Zip či zdrhovadlo je zařízení sloužící ke spojování dvou částí dohromady. Je nejčastěji využíván na oděvech, ale má mnohé další využití (na batozích, kufrech, sportovním vybavení a u pomůcek pro kempování).


History.

Earl Sutherland of Vanderbilt University won a Nobel Prize in Physiology or Medicine in 1971 "for his discoveries concerning the mechanisms of the action of hormones", especially epinephrine, via second messengers (such as cyclic adenosine monophosphate, cyclic AMP).

Synthesis.

Cyclic AMP is synthesized from ATP by adenylate cyclase located on the inner side of the plasma membrane and anchored at various locations in the interior of the cell. Adenylate cyclase is "activated" by a range of signaling molecules through the activation of adenylate cyclase stimulatory G (G)-protein-coupled receptors. Adenylate cyclase is "inhibited" by agonists of adenylate cyclase inhibitory G (G)-protein-coupled receptors. Liver adenylate cyclase responds more strongly to glucagon, and muscle adenylate cyclase responds more strongly to adrenaline.  cAMP decomposition into AMP is catalyzed by the enzyme phosphodiesterase.

Functions.

cAMP is a second messenger, used for intracellular signal transduction, such as transferring into cells the effects of hormones like glucagon and adrenaline, which cannot pass through the plasma membrane. It is also involved in the activation of protein kinases. In addition, cAMP binds to and regulates the function of ion channels such as the HCN channels and a few other cyclic nucleotide-binding proteins such as Epac1 and RAPGEF2.

Role in eukaryotic cells.

cAMP is associated with kinases function in several biochemical processes, including the regulation of glycogen, sugar, and lipid metabolism.  In eukaryotes, cyclic AMP works by activating protein kinase A (PKA, or cAMP-dependent protein kinase). PKA is normally inactive as a tetrameric holoenzyme, consisting of two catalytic and two regulatory units (CR), with the regulatory units blocking the catalytic centers of the catalytic units.  Cyclic AMP binds to specific locations on the regulatory units of the protein kinase, and causes dissociation between the regulatory and catalytic subunits, thus enabling those catalytic units to phosphorylate substrate proteins.  The active subunits catalyze the transfer of phosphate from ATP to specific serine or threonine residues of protein substrates. The phosphorylated proteins may act directly on the cell's ion channels, or may become activated or inhibited enzymes. Protein kinase A can also phosphorylate specific proteins that bind to promoter regions of DNA, causing increases in transcription. Not all protein kinases respond to cAMP. Several classes of protein kinases, including protein kinase C, are not cAMP-dependent.  Further effects mainly depend on cAMP-dependent protein kinase, which vary based on the type of cell.  Still, there are some minor PKA-independent functions of cAMP, e.g., activation of calcium channels, providing a minor pathway by which growth hormone-releasing hormone causes a release of growth hormone.  However, the view that the majority of the effects of cAMP are controlled by PKA is an outdated one. In 1998 a family of cAMP-sensitive proteins with guanine nucleotide exchange factor (GEF) activity was discovered. These are termed Exchange proteins activated by cAMP (Epac) and the family comprises Epac1 and Epac2. The mechanism of activation is similar to that of PKA: the GEF domain is usually masked by the N-terminal region containing the cAMP binding domain. When cAMP binds, the domain dissociates and exposes the now-active GEF domain, allowing Epac to activate small Ras-like GTPase proteins, such as Rap1.

Additional role of secreted cAMP in social amoebae.

In the species "Dictyostelium discoideum", cAMP acts outside the cell as a secreted signal. The chemotactic aggregation of cells is organized by periodic waves of cAMP that propagate between cells over distances as large as several centimetres. The waves are the result of a regulated production and secretion of extracellular cAMP and a spontaneous biological oscillator that initiates the waves at centers of territories.

Role in bacteria.

In bacteria, the level of cAMP varies depending on the medium used for growth. In particular, cAMP is low when glucose is the carbon source. This occurs through inhibition of the cAMP-producing enzyme, adenylate cyclase, as a side-effect of glucose transport into the cell. The transcription factor cAMP receptor protein (CRP) also called CAP (catabolite gene activator protein) forms a complex with cAMP and thereby is activated to bind to DNA. CRP-cAMP increases expression of a large number of genes, including some encoding enzymes that can supply energy independent of glucose.  cAMP, for example, is involved in the positive regulation of the lac operon. In an environment with a low glucose concentration, cAMP accumulates and binds to the allosteric site on CRP (cAMP receptor protein), a transcription activator protein. The protein assumes its active shape and binds to a specific site upstream of the lac promoter, making it easier for RNA polymerase to bind to the adjacent promoter to start transcription of the lac operon, increasing the rate of lac operon transcription. With a high glucose concentration, the cAMP concentration decreases, and the CRP disengages from the lac operon.

Pathology.

Since cyclic AMP is a second messenger and plays vital role in cell signalling, it has been implicated in various disorders but not restricted to the roles given below:

Role in human carcinoma.

Some research has suggested that a deregulation of cAMP pathways and an aberrant activation of cAMP-controlled genes is linked to the growth of some cancers.

Role in prefrontal cortex disorders.

Recent research suggests that cAMP affects the function of higher-order thinking in the prefrontal cortex through its regulation of ion channels called hyperpolarization-activated cyclic nucleotide-gated channels (HCN). When cAMP stimulates the HCN, the channels open, closing the brain cell to communication and thus interfering with the function of the prefrontal cortex. This research, especially the cognitive deficits in age-related illnesses and ADHD, is of interest to researchers studying the brain.

Cyclic adenosine monophosphate (cAMP, cyclic AMP, or 3',5'-cyclic adenosine monophosphate) is a second messenger important in many biological processes. cAMP is a derivative of adenosine triphosphate (ATP) and used for intracellular signal transduction in many different organisms, conveying the cAMP-dependent pathway. It should not be confused with 5'-AMP-activated protein kinase (AMP-activated protein kinase).

Cyklický adenosinmonofosfát (cAMP, cyklický AMP) je derivátem adenosintrifosfátu (ATP) a většina prokaryotických i eukaryotických buněk ho využívá jako vnitrobuněčného druhého posla v řadě signálních drah. Působí tak obvykle jako aktivátor proteinkináz. Většina funkcí cAMP u mnohobuněčných organizmů, jako je člověk, je spjata s proteinkinázou A. Cyklický AMP se váže na tuto kinázu a aktivuje ji, čímž spouští rozličné buněčné procesy.


Command and service module.

The major part of the Apollo spacecraft was a three-man vehicle designed for Earth orbital, translunar, and lunar orbital flight, and return to Earth. This consisted of a "command module" supported by a "service module", built by North American Aviation (later North American Rockwell).

Command module (CM).

The command module was the control center for the Apollo spacecraft and living quarters for the three crewmen. It contained the pressurized main crew cabin, crew couches, control and instrument panel, Primary Guidance, Navigation and Control System, communications systems, environmental control system, batteries, heat shield, reaction control system to provide attitude control, forward docking hatch, side hatch, five windows, and a parachute recovery system. It was the only part of the Apollo/Saturn space vehicle that returned to Earth intact.

Service module (SM).

The service module was unpressurized and contained a main service propulsion engine and hypergolic propellant to enter and leave lunar orbit, a reaction control system to provide attitude control and translational capability, fuel cells with hydrogen and oxygen reactants, radiators to dump waste heat into space, and a high gain antenna. The oxygen was also used for breathing, and the fuel cells produced water for drinking and environmental control. On Apollo 15, 16 and 17 it also carried a scientific instrument package, with a mapping camera and a small sub-satellite to study the Moon.  A major portion of the service module was taken up by propellant and the main rocket engine. Capable of multiple restarts, this engine placed the Apollo spacecraft into and out of lunar orbit, and was used for mid-course corrections between the Earth and the Moon.  The service module remained attached to the command module throughout the mission. It was jettisoned just prior to reentry into the Earth's atmosphere.

Lunar Module (LM).

The Apollo Lunar Module was a separate vehicle designed to land on the Moon and return to lunar orbit, and was the first true "spaceship" since it flew solely in the vacuum of space. It consisted of a "descent stage" and an "ascent stage". It supplied life support systems for two astronauts for up to four to five days on the Apollo 15, 16 and 17 missions. The spacecraft was designed and manufactured by the Grumman Aircraft Company.  The descent stage contained the landing gear, landing radar antenna, descent propulsion system, and fuel to land on the Moon. It also had several cargo compartments used to carry, among other things: the Apollo Lunar Surface Experiment Packages ALSEP, the modularized equipment transporter (MET) (a hand-pulled equipment cart used on Apollo 14), the Lunar Rover (Apollo 15, 16 and 17), a surface television camera, surface tools, and lunar sample collection boxes.  The ascent stage contained the crew cabin, instrument panels, overhead hatch/docking port, forward hatch, optical and electronic guidance systems, reaction control system, radar and communications antennas, ascent rocket engine and propellant to return to lunar orbit and rendezvous with the Apollo Command and Service Modules.

Spacecraft–lunar module adapter (SLA).

The spacecraft–LM adapter (SLA), built by North American Aviation (Rockwell), was a conical aluminum structure that connected the service module to the Saturn S-IVB rocket stage. It also protected the LM, the service propulsion system engine nozzle, and the launch vehicle to service module umbilical during launch and ascent through the atmosphere.  The SLA was composed of four fixed tall panels bolted to the Instrument Unit on top of the S-IVB stage, which were connected via hinges to four panels which would open from the top similar to flower petals.  The SLA was made from thick aluminum honeycomb material. The exterior of the SLA was covered by a thin () layer of cork and painted white to minimize thermal stresses during launch and ascent.  The service module was bolted to a flange at the top of the longer panels, and power to the SLA multiply-redundant pyrotechnics was provided by an umbilical. Because a failure to separate from the S-IVB stage could leave the crew stranded in orbit, the separation system used multiple signal paths, multiple detonators and multiple explosive charges where the detonation of one charge would set off another even if the detonator on that charge failed to function.  Once in space, the astronauts pressed the 'CSM/LV Sep' button on the control panel to separate the CSM from the launch vehicle. Detonating cord was ignited around the flange between the SM and SLA, and along the joints between the four SLA panels, releasing the SM and blowing apart the connections between the panels. Dual-redundant pyrotechnic thrusters at the lower end of the SLA panels then fired to rotate them around the hinges at 30-60 degrees per second.  On all flights through Apollo 7, the SLA panels remained hinged to the S-IVB and opened to a 45-degree angle, as originally designed. But as the Apollo 7 crew practiced rendezvous with the S-IVB/SLA containing a dummy docking target, one panel did not open to the full 45 degrees, raising concern about the possibility of collision between the spacecraft and the SLA panels during docking and extraction of the LM in a lunar mission. This led to a redesign using a spring-loaded hinge release system which released the panels at the 45 degree angle and pushed them away from the S-IVB at a velocity of about 8 km/h (5 m.p.h.), putting them a safe distance away by the time the astronauts pulled the CSM away, rotated it through 180 degrees, and came back for docking.  The LM was connected to the SLA at four points around the lower panels. After the astronauts docked the CSM to the LM, they blew charges to separate those connections and a guillotine severed the LM-to-instrument-unit umbilical. After the charges fired, springs pushed the LM away from the S-IVB and the astronauts were free to continue their trip to the Moon.

Launch escape system (LES).

The Apollo launch escape system (LES) was built by the Lockheed Propulsion Company. Its purpose was to abort the mission by pulling the CM (the crew cabin) away from the launch vehicle in an emergency, such as a pad fire before launch, guidance failure, or launch vehicle failure likely to lead to an imminent explosion.  The LES included three wires that ran down the exterior of the launch vehicle. If the signals from any two of the wires were lost, the LES would activate automatically. Alternatively, the Commander could activate the system manually using one of two translation controller handles, which were switched to a special abort mode for launch. When activated, the LES would fire a solid fuel escape rocket and open a canard system to direct the CM away from, and off the path of, a launch vehicle in trouble. The LES would then jettison and the CM would land with its parachute recovery system.  If the emergency happened on the launch pad, the LES would lift the CM to a sufficient height to allow the recovery parachutes to deploy safely before coming in contact with the ground.  In the absence of an emergency, the LES was routinely jettisoned about 20 or 30 seconds after the launch vehicle's second-stage ignition, using a separate solid-fuel rocket motor manufactured by the Thiokol Chemical Company. Abort modes after this point would be accomplished without the LES. The LES was carried but never used on four uncrewed Apollo flights, and fifteen crewed Apollo, Skylab, and Apollo-Soyuz Test Project flights.

Current locations of spacecraft.

The disposition of all command modules, and all unflown service modules is listed at Apollo command and service module#CSMs produced. (All flown service modules burned up in the Earth's atmosphere at termination of the missions.)  The disposition of all lunar modules is listed at Apollo Lunar Module#Lunar modules produced.

The Apollo spacecraft was composed of three parts designed to accomplish the American Apollo program's goal of landing astronauts on the Moon by the end of the 1960s and returning them safely to Earth. The expendable (single-use) spacecraft consisted of a combined command and service module (CSM) and an Apollo Lunar Module (LM). Two additional components complemented the spacecraft stack for space vehicle assembly: a spacecraft–LM adapter (SLA) designed to shield the LM from the aerodynamic stress of launch and to connect the CSM to the Saturn launch vehicle and a launch escape system (LES) to carry the crew in the command module safely away from the launch vehicle in the event of a launch emergency.

Apollo je kosmická loď, vyvinutá v rámci programu Apollo (přistání lidí na Měsíci). Později byla použita i v programu Sojuz-Apollo a Skylab.