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Frankfurt Stock Exchange

The Frankfurt Stock Exchange is the world's 10th largest stock exchange by market capitalization. Located in Frankfurt, the Frankfurt Stock Exchange is owned and operated by Deutsche Börse AG and Börse Frankfurt Zertifikate AG, it is located in the district of Innenstadt and within the central business district known as Bankenviertel. With 90 per cent of its turnover generated in Germany, namely at the two trading venues Xetra and Börse Frankfurt, the Frankfurt Stock Exchange is the largest of the seven regional securities exchanges in Germany; the trading indices are DAX, DAXplus, CDAX, DivDAX, LDAX, MDAX, SDAX, TecDAX, VDAX and EuroStoxx 50. Through its Deutsche Börse Cash Market business section, Deutsche Börse AG now operates two trading venues at the Frankfurt Stock Exchange. Xetra is the reference market for exchange trading in exchange traded funds. In 2015, 90 per cent of all trading in shares at all German exchanges was transacted through the Xetra. With regard to DAX listings, Xetra has 60 per cent market share throughout Europe.

Trading times on trading days are from 9.00 a.m. to 5.30 p.m. The prices on Xetra serve as the basis for calculating the best-known German share index. Over 200 trading participants from 16 European countries, plus Hong Kong and the United Arab Emirates, are connected via Xetra servers in Frankfurt/Main. Börse Frankfurt is the trading venue for private investors with more than one million securities of German and international issuers. So named Specialists on the trading floor attend to the trading of the securities. Trading at the Frankfurt Stock Exchange is governed by clear rules, which apply for all trading participants. Independent market surveillance is made up of the Trading Surveillance Office, the Exchange Supervisory Authority attached to the Hessian Ministry of Economic Affairs and Regional Development, the Federal Financial Supervisory Authority. With a view to improving the continuity of prices and to avoid mistrades, several protective mechanisms are in place for the trading venues Xetra and Börse Frankfurt.

These include volatility interruption, market order interruption, liquidity interruption measures. The origins of the Frankfurt Stock Exchange go back to medieval trade fairs in the 11th century. By the 16th century Frankfurt developed into a wealthy and busy city with an economy based on trade and financial services. In 1585 a bourse was established to set up fixed currency exchange rates, considered to mark the'birth' of the stock exchange. During the following centuries Frankfurt developed into one of the world's first stock exchanges - next to London and Paris. Bankers like Mayer Amschel Rothschild and Max Warburg had substantial influence on Frankfurt's financial trade. In 1879 Frankfurt Stock Exchange moved into its new building at Börsenplatz, it was only in 1949 after World War II that the Frankfurt Stock Exchange established as the leading stock exchange in Germany with incoming national and international investments. During the 1990s the Frankfurt Stock Exchange was bourse for the Neuer Markt as part of the worldwide dot-com boom.

In 1993 the Frankfurter Wertpapierbörse became Deutsche Börse AG, operating businesses for the exchange. From the early 1960s onwards the Frankfurt Stock Exchange took advantage of the close by Bundesbank which decided on financial policies in Europe until the introduction of the euro in 2002. Since the exchange profits from the presence of the European Central Bank in Frankfurt. In 2002 and 2004 Deutsche Börse was in advanced negotiations to take over London Stock Exchange, which were broken off in 2005. A further merger bid was blocked by the European Commission in 2017. Financial Market Integration in a Wider European Union International financial centres: rivals or partner? Assessment on Frankfurt's failed take-over of LSE Deutsche Börse Cash Market - Organisation of the FWB Website of trading venue Xetra Website of trading venue Börse Frankfurt Federation of European Securities Exchanges, Brussels Clippings about Frankfurt Stock Exchange in the 20th Century Press Archives of the ZBW

Embassy of Germany, Brasília

The Embassy of Germany in Brasília is Germany's embassy to Brazil. It is located on Avenida das Nações, Lote 25, Quadra 807; the embassy building was designed by German architect Hans Scharoun. The current ambassador is Georg Witschel. There are several consulates located through Brazil: Consulate General in Porto Alegre Consulate General in Recife Consulate General in Rio de Janeiro Consulate General in São Paulo as well as several Honorary Consuls in Anápolis, Belém, Belo Horizonte, Cuiabá, Fortaleza, Manaus, Ribeirão Preto, Rolândia, Salvador and Vitória

Uracil

Uracil is one of the four nucleobases in the nucleic acid of RNA that are represented by the letters A, G, C and U. The others are adenine and guanine. In RNA, uracil binds to adenine via two hydrogen bonds. In DNA, the uracil nucleobase is replaced by thymine. Uracil is a demethylated form of thymine. Uracil is a common and occurring pyrimidine derivative; the name "uracil" was coined in 1885 by the German chemist Robert Behrend, attempting to synthesize derivatives of uric acid. Discovered in 1900 by Alberto Ascoli, it was isolated by hydrolysis of yeast nuclein, it is a unsaturated compound that has the ability to absorb light. Based on 12C/13C isotopic ratios of organic compounds found in the Murchison meteorite, it is believed that uracil and related molecules can be formed extraterrestrially. In 2012, an analysis of data from the Cassini mission orbiting in the Saturn system showed that Titan's surface composition may include uracil. In RNA, uracil base-pairs with adenine and replaces thymine during DNA transcription.

Methylation of uracil produces thymine. In DNA, the evolutionary substitution of thymine for uracil may have increased DNA stability and improved the efficiency of DNA replication. Uracil pairs with adenine through hydrogen bonding; when base pairing with adenine, uracil acts as both a hydrogen bond acceptor and a hydrogen bond donor. In RNA, uracil binds with a ribose sugar to form the ribonucleoside uridine; when a phosphate attaches to uridine, uridine 5'-monophosphate is produced. Uracil undergoes amide-imidic acid tautomeric shifts because any nuclear instability the molecule may have from the lack of formal aromaticity is compensated by the cyclic-amidic stability; the amide tautomer is referred to as the lactam structure, while the imidic acid tautomer is referred to as the lactim structure. These tautomeric forms are predominant at pH 7; the lactam structure is the most common form of uracil. Uracil recycles itself to form nucleotides by undergoing a series of phosphoribosyltransferase reactions.

Degradation of uracil produces the substrates aspartate, carbon dioxide, ammonia. C4H4N2O2 → H3NCH2CH2COO− + NH4+ + CO2Oxidative degradation of uracil produces urea and maleic acid in the presence of H2O2 and Fe2+ or in the presence of diatomic oxygen and Fe2+. Uracil is a weak acid; the first site of ionization of uracil is not known. The negative charge is placed on the oxygen anion and produces a pKa of less than or equal to 12; the basic pKa = -3.4, while the acidic pKa = 9.389. In the gas phase, uracil has 4 sites. Uracil is found in DNA, this may have been an evolutionary change to increase genetic stability; this is because cytosine can deaminate spontaneously to produce uracil through hydrolytic deamination. Therefore, if there were an organism that used uracil in its DNA, the deamination of cytosine would lead to formation of uracil during DNA synthesis. Uracil-DNA glycosylase excises uracil bases from double-stranded DNA; this enzyme would therefore recognize and cut out both types of uracil – the one incorporated and the one formed due to cytosine deamination, which would trigger unnecessary and inappropriate repair processes.

This problem is believed to have been solved in terms of evolution, i.e. by "tagging" uracil. Methylated uracil is identical to thymine. Hence the hypothesis that, over time, thymine became standard in DNA instead of uracil. So cells continue to use uracil in RNA, not in DNA, because RNA is shorter-lived than DNA, any potential uracil-related errors do not lead to lasting damage. Either there was no evolutionary pressure to replace uracil in RNA with the more complex thymine, or uracil has some chemical property, useful in RNA, which thymine lacks. Uracil-containing DNA still exists, for example in DNA of several phages Endopterygote development Hypermutations during the synthesis of vertebrate antibodies. In a scholarly article published in October 2009, NASA scientists reported having reproduced uracil from pyrimidine by exposing it to ultraviolet light under space-like conditions; this suggests that one possible natural original source for uracil in the RNA world could have been panspermia.

More in March 2015, NASA scientists reported that, for the first time, additional complex DNA and RNA organic compounds of life, including uracil and thymine, have been formed in the laboratory under outer space conditions, using starting chemicals, such as pyrimidine, found in meteorites. Pyrimidine, like polycyclic aromatic hydrocarbons, the most carbon-rich chemical found in the Universe, may have been formed in red giants or in interstellar dust and gas clouds, according to the scientists. There are many laboratory syntheses of uracil available; the first reaction is the simplest of the syntheses, by adding water to cytosine to produce uracil and ammonia: C4H5N3O + H2O → C4H4N2O2 + NH3The most common way to synthesize uracil is by the condensation of malic acid with urea in fuming sulfuric acid: C4H4O4 + NH2CONH2 → C4H4N2O2 + 2 H2O + COUracil can be synthesized by a double decomposition of thiouracil in aqueous chloroacetic acid. Photodehydrogenation of 5,6-diuracil, synthesized by beta-alanine reacting with urea, produces uracil.

Uracil undergoes regular reactions including oxidation and alkylation. While in the presence of phenol and sodium hypochlorite, uracil can be visualized in ultraviolet light. Uracil has the capability to react with elemental halogens because of the presence of more than one e