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Tucson is known for being a trailblazer in voluntary partial publicly financed campaigns. Since 1985, both mayoral and council candidates have been eligible to receive matching public funds from the city. To become eligible, council candidates must receive 200 donations of $10 or more (300 for a mayoral candidate). Candidates must then agree to spending limits equal to 33¢ for every registered Tucson voter, or $79,222 in 2005 (the corresponding figures for mayor are 64¢ per registered voter, or $142,271 in 2003). In return, candidates receive matching funds from the city at a 1:1 ratio of public money to private donations. The only other limitation is that candidates may not exceed 75% of the limit by the date of the primary. Many cities, such as San Francisco and New York City, have copied this system, albeit with more complex spending and matching formulas.
Tucson has one daily newspaper, the morning Arizona Daily Star. Wick Communications publishes the daily legal paper The Daily Territorial, while Boulder, Colo.-based 10/13 Communications publishes Tucson Weekly (an "alternative" publication), Inside Tucson Business and the Explorer. TucsonSentinel.com is a nonprofit independent online news organization. Tucson Lifestyle Magazine, Lovin' Life News, DesertLeaf, and Zócalo Magazine are monthly publications covering arts, architecture, decor, fashion, entertainment, business, history, and other events. The Arizona Daily Wildcat is the University of Arizona's student newspaper, and the Aztec News is the Pima Community College student newspaper. The New Vision is the newspaper for the Roman Catholic Diocese of Tucson, and the Arizona Jewish Post is the newspaper of the Jewish Federation of Southern Arizona.
The Tucson metro area is served by many local television stations and is the 68th largest designated market area (DMA) in the U.S. with 433,310 homes (0.39% of the total U.S.). It is limited to the three counties of southeastern Arizona (Pima, Santa Cruz, and Cochise) The major television networks serving Tucson are: KVOA 4 (NBC), KGUN 9 (ABC), KMSB-TV 11 (Fox), KOLD-TV 13 (CBS), KTTU 18 (My Network TV) and KWBA 58 (The CW). KUAT-TV 6 is a PBS affiliate run by the University of Arizona (as is sister station KUAS 27).
Tucson's primary electrical power source is a coal and natural gas power-plant managed by Tucson Electric Power that is situated within the city limits on the south-western boundary of Davis-Monthan Air-force base adjacent to Interstate-10. The air pollution generated has raised some concerns as the Sundt operating station has been online since 1962 as is exempt from many pollution standards and controls due to its age. Solar has been gaining ground in Tucson with its ideal over 300 days of sunshine climate. Federal, state, and even local utility credits and incentives have also enticed residents to equip homes with solar systems. Davis-Monthan AFB has a 3.3 Megawatt (MW) ground-mounted solar photovoltaic (PV) array and a 2.7 MW rooftop-mounted PV array, both of which are located in the Base Housing area. The base will soon have the largest solar-generating capacity in the United States Department of Defense after awarding a contract on September 10, 2010, to SunEdison to construct a 14.5 MW PV field on the northwestern side of the base.
Perhaps the biggest sustainability problem in Tucson, with its high desert climate, is potable water supply. The state manages all water in Arizona through its Arizona Department of Water Resources (ADWR). The primary consumer of water is Agriculture (including golf courses), which consumes about 69% of all water. Municipal (which includes residential use) accounts for about 25% of use. Energy consumption and availability is another sustainability issue. However, with over 300 days of full sun a year, Tucson has demonstrated its potential to be an ideal solar energy producer.
In an effort to conserve water, Tucson is recharging groundwater supplies by running part of its share of CAP water into various open portions of local rivers to seep into their aquifer. Additional study is scheduled to determine the amount of water that is lost through evaporation from the open areas, especially during the summer. The City of Tucson already provides reclaimed water to its inhabitants, but it is only used for "applications such as irrigation, dust control, and industrial uses." These resources have been in place for more than 27 years, and deliver to over 900 locations.
To prevent further loss of groundwater, Tucson has been involved in water conservation and groundwater preservation efforts, shifting away from its reliance on a series of Tucson area wells in favor of conservation, consumption-based pricing for residential and commercial water use, and new wells in the more sustainable Avra Valley aquifer, northwest of the city. An allocation from the Central Arizona Project Aqueduct (CAP), which passes more than 300 mi (480 km) across the desert from the Colorado River, has been incorporated into the city's water supply, annually providing over 20 million gallons of "recharged" water which is pumped into the ground to replenish water pumped out. Since 2001, CAP water has allowed the city to remove or turn off over 80 wells.
Tucson's Sun Tran bus system serves greater Tucson with standard, express, regional shuttle, and on-demand shuttle bus service. It was awarded Best Transit System in 1988 and 2005. A 3.9-mile streetcar line, Sun Link, connects the University of Arizona campus with 4th Avenue, downtown, and the Mercado District west of Interstate 10 and the Santa Cruz River. Ten-minute headway passenger service began July 25, 2014. The streetcar utilizes Sun Tran's card payment and transfer system, connecting with the University of Arizona's CatTran shuttles, Amtrak, and Greyhound intercity bus service.
Cycling is popular in Tucson due to its flat terrain and dry climate. Tucson and Pima County maintain an extensive network of marked bike routes, signal crossings, on-street bike lanes, mountain-biking trails, and dedicated shared-use paths. The Loop is a network of seven linear parks comprising over 100 mi (160 km) of paved, vehicle-free trails that encircles the majority of the city with links to Marana and Oro Valley. The Tucson-Pima County Bicycle Advisory Committee (TPCBAC) serves in an advisory capacity to local governments on issues relating to bicycle recreation, transportation, and safety. Tucson was awarded a gold rating for bicycle-friendliness by the League of American Bicyclists in 2006.
Armenia is a unitary, multi-party, democratic nation-state with an ancient cultural heritage. Urartu was established in 860 BC and by the 6th century BC it was replaced by the Satrapy of Armenia. In the 1st century BC the Kingdom of Armenia reached its height under Tigranes the Great. Armenia became the first state in the world to adopt Christianity as its official religion. In between the late 3rd century to early years of the 4th century, the state became the first Christian nation. The official date of state adoption of Christianity is 301 AD. The ancient Armenian kingdom was split between the Byzantine and Sasanian Empires around the early 5th century.
Between the 16th century and 19th century, the traditional Armenian homeland composed of Eastern Armenia and Western Armenia came under the rule of the Ottoman and successive Iranian empires, repeatedly ruled by either of the two over the centuries. By the 19th century, Eastern Armenia had been conquered by the Russian Empire, while most of the western parts of the traditional Armenian homeland remained under Ottoman rule. During World War I, Armenians living in their ancestral lands in the Ottoman Empire were systematically exterminated in the Armenian Genocide. In 1918, after the Russian Revolution, all non-Russian countries declared their independence from the Russian empire, leading to the establishment of the First Republic of Armenia. By 1920, the state was incorporated into the Transcaucasian Socialist Federative Soviet Republic, and in 1922 became a founding member of the Soviet Union. In 1936, the Transcaucasian state was dissolved, transforming its constituent states, including the Armenian Soviet Socialist Republic, into full Union republics. The modern Republic of Armenia became independent in 1991 during the dissolution of the Soviet Union.
The exonym Armenia is attested in the Old Persian Behistun Inscription (515 BC) as Armina ( ). The ancient Greek terms Ἀρμενία (Armenía) and Ἀρμένιοι (Arménioi, "Armenians") are first mentioned by Hecataeus of Miletus (c. 550 BC – c. 476 BC). Xenophon, a Greek general serving in some of the Persian expeditions, describes many aspects of Armenian village life and hospitality in around 401 BC. He relates that the people spoke a language that to his ear sounded like the language of the Persians. According to the histories of both Moses of Chorene and Michael Chamchian, Armenia derives from the name of Aram, a lineal descendant of Hayk.
Several bronze-era states flourished in the area of Greater Armenia, including the Hittite Empire (at the height of its power), Mitanni (South-Western historical Armenia), and Hayasa-Azzi (1500–1200 BC). The Nairi people (12th to 9th centuries BC) and the Kingdom of Urartu (1000–600 BC) successively established their sovereignty over the Armenian Highland. Each of the aforementioned nations and tribes participated in the ethnogenesis of the Armenian people. A large cuneiform lapidary inscription found in Yerevan established that the modern capital of Armenia was founded in the summer of 782 BC by King Argishti I. Yerevan is the world's oldest city to have documented the exact date of its foundation.
During the late 6th century BC, the first geographical entity that was called Armenia by neighboring populations was established under the Orontid Dynasty within the Achaemenid Empire, as part of the latters' territories. The kingdom became fully sovereign from the sphere of influence of the Seleucid Empire in 190 BC under King Artaxias I and begun the rule of the Artaxiad dynasty. Armenia reached its height between 95 and 66 BC under Tigranes the Great, becoming the most powerful kingdom of its time east of the Roman Republic.
In the next centuries, Armenia was in the Persian Empire's sphere of influence during the reign of Tiridates I, the founder of the Arsacid dynasty of Armenia, which itself was a branch of the eponymous Arsacid dynasty of Parthia. Throughout its history, the kingdom of Armenia enjoyed both periods of independence and periods of autonomy subject to contemporary empires. Its strategic location between two continents has subjected it to invasions by many peoples, including the Assyrians (under Ashurbanipal, at around 669–627 BC, the boundaries of the Assyrian Empire reached as far as Armenia & the Caucasus Mountains), Medes, Achaemenid Persians, Greeks, Parthians, Romans, Sassanid Persians, Byzantines, Arabs, Seljuks, Mongols, Ottomans, successive Iranian Safavids, Afsharids, and Qajars, and the Russians.
After the Marzpanate period (428–636), Armenia emerged as the Emirate of Armenia, an autonomous principality within the Arabic Empire, reuniting Armenian lands previously taken by the Byzantine Empire as well. The principality was ruled by the Prince of Armenia, and recognized by the Caliph and the Byzantine Emperor. It was part of the administrative division/emirate Arminiya created by the Arabs, which also included parts of Georgia and Caucasian Albania, and had its center in the Armenian city, Dvin. The Principality of Armenia lasted until 884, when it regained its independence from the weakened Arab Empire under King Ashot I Bagratuni.
In 1045, the Byzantine Empire conquered Bagratid Armenia. Soon, the other Armenian states fell under Byzantine control as well. The Byzantine rule was short lived, as in 1071 Seljuk Turks defeated the Byzantines and conquered Armenia at the Battle of Manzikert, establishing the Seljuk Empire. To escape death or servitude at the hands of those who had assassinated his relative, Gagik II, King of Ani, an Armenian named Roupen, went with some of his countrymen into the gorges of the Taurus Mountains and then into Tarsus of Cilicia. The Byzantine governor of the palace gave them shelter where the Armenian Kingdom of Cilicia was eventually established on 6 January 1198 under King Leo I, a descendant of Prince Roupen.
The Seljuk Empire soon started to collapse. In the early 12th century, Armenian princes of the Zakarid noble family drove out the Seljuk Turks and established a semi-independent Armenian principality in Northern and Eastern Armenia, known as Zakarid Armenia, which lasted under the patronage of the Georgian Kingdom. The noble family of Orbelians shared control with the Zakarids in various parts of the country, especially in Syunik and Vayots Dzor, while the Armenian family of Hasan-Jalalians controlled provinces of Artsakh and Utik as the Kingdom of Artsakh.
In the 16th century, the Ottoman Empire and Safavid Empire divided Armenia. From the early 16th century, both Western Armenia and Eastern Armenia fell under Iranian Safavid rule. Owing to the century long Turco-Iranian geo-political rivalry that would last in Western Asia, significant parts of the region were frequently fought over between the two rivalling empires. From the mid 16th century with the Peace of Amasya, and decisively from the first half of the 17th century with the Treaty of Zuhab until the first half of the 19th century, Eastern Armenia was ruled by the successive Iranian Safavid, Afsharid and Qajar empires, while Western Armenia remained under Ottoman rule.
While Western Armenia still remained under Ottoman rule, the Armenians were granted considerable autonomy within their own enclaves and lived in relative harmony with other groups in the empire (including the ruling Turks). However, as Christians under a strict Muslim social system, Armenians faced pervasive discrimination. When they began pushing for more rights within the Ottoman Empire, Sultan ‘Abdu’l-Hamid II, in response, organized state-sponsored massacres against the Armenians between 1894 and 1896, resulting in an estimated death toll of 80,000 to 300,000 people. The Hamidian massacres, as they came to be known, gave Hamid international infamy as the "Red Sultan" or "Bloody Sultan."
During the 1890s, the Armenian Revolutionary Federation, commonly known as Dashnaktsutyun, became active within the Ottoman Empire with the aim of unifying the various small groups in the empire that were advocating for reform and defending Armenian villages from massacres that were widespread in some of the Armenian-populated areas of the empire. Dashnaktsutyun members also formed fedayi groups that defended Armenian civilians through armed resistance. The Dashnaks also worked for the wider goal of creating a "free, independent and unified" Armenia, although they sometimes set aside this goal in favor of a more realistic approach, such as advocating autonomy.
The Ottoman Empire began to collapse, and in 1908, the Young Turk Revolution overthrew the government of Sultan Hamid. In April 1909, the Adana massacre occurred in the Adana Vilayet of the Ottoman Empire resulting in the deaths of as many as 20,000–30,000 Armenians. The Armenians living in the empire hoped that the Committee of Union and Progress would change their second-class status. Armenian reform package (1914) was presented as a solution by appointing an inspector general over Armenian issues.
When World War I broke out leading to confrontation between the Ottoman Empire and the Russian Empire in the Caucasus and Persian Campaigns, the new government in Istanbul began to look on the Armenians with distrust and suspicion. This was because the Imperial Russian Army contained a contingent of Armenian volunteers. On 24 April 1915, Armenian intellectuals were arrested by Ottoman authorities and, with the Tehcir Law (29 May 1915), eventually a large proportion of Armenians living in Anatolia perished in what has become known as the Armenian Genocide.
The genocide was implemented in two phases: the wholesale killing of the able-bodied male population through massacre and subjection of army conscripts to forced labour, followed by the deportation of women, children, the elderly and infirm on death marches leading to the Syrian desert. Driven forward by military escorts, the deportees were deprived of food and water and subjected to periodic robbery, rape, and massacre. There was local Armenian resistance in the region, developed against the activities of the Ottoman Empire. The events of 1915 to 1917 are regarded by Armenians and the vast majority of Western historians to have been state-sponsored mass killings, or genocide.
Turkish authorities deny the genocide took place to this day. The Armenian Genocide is acknowledged to have been one of the first modern genocides. According to the research conducted by Arnold J. Toynbee, an estimated 600,000 Armenians died during deportation from 1915–16). This figure, however, accounts for solely the first year of the Genocide and does not take into account those who died or were killed after the report was compiled on the 24th May 1916. The International Association of Genocide Scholars places the death toll at "more than a million". The total number of people killed has been most widely estimated at between 1 and 1.5 million.
Although the Russian Caucasus Army of Imperial forces commanded by Nikolai Yudenich and Armenians in volunteer units and Armenian militia led by Andranik Ozanian and Tovmas Nazarbekian succeeded in gaining most of Ottoman Armenia during World War I, their gains were lost with the Bolshevik Revolution of 1917.[citation needed] At the time, Russian-controlled Eastern Armenia, Georgia, and Azerbaijan attempted to bond together in the Transcaucasian Democratic Federative Republic. This federation, however, lasted from only February to May 1918, when all three parties decided to dissolve it. As a result, the Dashnaktsutyun government of Eastern Armenia declared its independence on 28 May as the First Republic of Armenia under the leadership of Aram Manukian.
At the end of the war, the victorious powers sought to divide up the Ottoman Empire. Signed between the Allied and Associated Powers and Ottoman Empire at Sèvres on 10 August 1920, the Treaty of Sèvres promised to maintain the existence of the Armenian republic and to attach the former territories of Ottoman Armenia to it. Because the new borders of Armenia were to be drawn by United States President Woodrow Wilson, Ottoman Armenia was also referred to as "Wilsonian Armenia." In addition, just days prior, on 5 August 1920, Mihran Damadian of the Armenian National Union, the de facto Armenian administration in Cilicia, declared the independence of Cilicia as an Armenian autonomous republic under French protectorate.
In 1920, Turkish nationalist forces invaded the fledgling Armenian republic from the east. Turkish forces under the command of Kazım Karabekir captured Armenian territories that Russia had annexed in the aftermath of the 1877–1878 Russo-Turkish War and occupied the old city of Alexandropol (present-day Gyumri). The violent conflict finally concluded with the Treaty of Alexandropol on 2 December 1920. The treaty forced Armenia to disarm most of its military forces, cede all former Ottoman territory granted to it by the Treaty of Sèvres, and to give up all the "Wilsonian Armenia" granted to it at the Sèvres treaty. Simultaneously, the Soviet Eleventh Army, under the command of Grigoriy Ordzhonikidze, invaded Armenia at Karavansarai (present-day Ijevan) on 29 November. By 4 December, Ordzhonikidze's forces entered Yerevan and the short-lived Armenian republic collapsed.
Armenia was annexed by Bolshevist Russia and along with Georgia and Azerbaijan, it was incorporated into the Soviet Union as part of the Transcaucasian SFSR (TSFSR) on 4 March 1922. With this annexation, the Treaty of Alexandropol was superseded by the Turkish-Soviet Treaty of Kars. In the agreement, Turkey allowed the Soviet Union to assume control over Adjara with the port city of Batumi in return for sovereignty over the cities of Kars, Ardahan, and Iğdır, all of which were part of Russian Armenia.
The TSFSR existed from 1922 to 1936, when it was divided up into three separate entities (Armenian SSR, Azerbaijan SSR, and Georgian SSR). Armenians enjoyed a period of relative stability under Soviet rule. They received medicine, food, and other provisions from Moscow, and communist rule proved to be a soothing balm in contrast to the turbulent final years of the Ottoman Empire. The situation was difficult for the church, which struggled under Soviet rule. After the death of Vladimir Lenin, Joseph Stalin took the reins of power and began an era of renewed fear and terror for Armenians.
Fears decreased when Stalin died in 1953 and Nikita Khruschev emerged as the Soviet Union's new leader. Soon, life in Soviet Armenia began to see rapid improvement. The church, which suffered greatly under Stalin, was revived when Catholicos Vazgen I assumed the duties of his office in 1955. In 1967, a memorial to the victims of the Armenian Genocide was built at the Tsitsernakaberd hill above the Hrazdan gorge in Yerevan. This occurred after mass demonstrations took place on the tragic event's fiftieth anniversary in 1965.
During the Gorbachev era of the 1980s, with the reforms of Glasnost and Perestroika, Armenians began to demand better environmental care for their country, opposing the pollution that Soviet-built factories brought. Tensions also developed between Soviet Azerbaijan and its autonomous district of Nagorno-Karabakh, a majority-Armenian region separated by Stalin from Armenia in 1923. About 484,000 Armenians lived in Azerbaijan in 1970. The Armenians of Karabakh demanded unification with Soviet Armenia. Peaceful protests in Yerevan supporting the Karabakh Armenians were met with anti-Armenian pogroms in the Azerbaijani city of Sumgait. Compounding Armenia's problems was a devastating earthquake in 1988 with a moment magnitude of 7.2.
Gorbachev's inability to alleviate any of Armenia's problems created disillusionment among the Armenians and fed a growing hunger for independence. In May 1990, the New Armenian Army (NAA) was established, serving as a defence force separate from the Soviet Red Army. Clashes soon broke out between the NAA and Soviet Internal Security Forces (MVD) troops based in Yerevan when Armenians decided to commemorate the establishment of the 1918 First Republic of Armenia. The violence resulted in the deaths of five Armenians killed in a shootout with the MVD at the railway station. Witnesses there claimed that the MVD used excessive force and that they had instigated the fighting.
Further firefights between Armenian militiamen and Soviet troops occurred in Sovetashen, near the capital and resulted in the deaths of over 26 people, mostly Armenians. The pogrom of Armenians in Baku in January 1990 forced almost all of the 200,000 Armenians in the Azerbaijani capital Baku to flee to Armenia. On 17 March 1991, Armenia, along with the Baltic states, Georgia and Moldova, boycotted a nationwide referendum in which 78% of all voters voted for the retention of the Soviet Union in a reformed form.
Ter-Petrosyan led Armenia alongside Defense Minister Vazgen Sargsyan through the Nagorno-Karabakh War with neighboring Azerbaijan. The initial post-Soviet years were marred by economic difficulties, which had their roots early in the Karabakh conflict when the Azerbaijani Popular Front managed to pressure the Azerbaijan SSR to instigate a railway and air blockade against Armenia. This move effectively crippled Armenia's economy as 85% of its cargo and goods arrived through rail traffic. In 1993, Turkey joined the blockade against Armenia in support of Azerbaijan.
The Karabakh war ended after a Russian-brokered cease-fire was put in place in 1994. The war was a success for the Karabakh Armenian forces who managed to capture 16% of Azerbaijan's internationally recognised territory including Nagorno-Karabakh itself. Since then, Armenia and Azerbaijan have held peace talks, mediated by the Organisation for Security and Co-operation in Europe (OSCE). The status of Karabakh has yet to be determined. The economies of both countries have been hurt in the absence of a complete resolution and Armenia's borders with Turkey and Azerbaijan remain closed. By the time both Azerbaijan and Armenia had finally agreed to a ceasefire in 1994, an estimated 30,000 people had been killed and over a million had been displaced.
International observers of Council of Europe and US Department of State have questioned the fairness of Armenia's parliamentary and presidential elections and constitutional referendum since 1995, citing polling deficiencies, lack of cooperation by the Electoral Commission, and poor maintenance of electoral lists and polling places. Freedom House categorized Armenia in its 2008 report as a "Semi-consolidated Authoritarian Regime" (along with Moldova, Kosovo, Kyrgyzstan, and Russia) and ranked Armenia 20th among 29 nations in transition, with a Democracy Score of 5.21 out of 7 (7 represents the lowest democratic progress).
Armenia presently maintains good relations with almost every country in the world, with two major exceptions being its immediate neighbours, Turkey and Azerbaijan. Tensions were running high between Armenians and Azerbaijanis during the final years of the Soviet Union. The Nagorno-Karabakh War dominated the region's politics throughout the 1990s. The border between the two rival countries remains closed up to this day, and a permanent solution for the conflict has not been reached despite the mediation provided by organisations such as the OSCE.
Turkey also has a long history of poor relations with Armenia over its refusal to acknowledge the Armenian Genocide. Turkey was one of the first countries to recognize the Republic of Armenia (the 3rd republic) after its independence from the USSR in 1991. Despite this, for most of the 20th century and early 21st century, relations remain tense and there are no formal diplomatic relations between the two countries due to Turkey's refusal to establish them for numerous reasons. During the Nagorno-Karabakh War and citing it as the reason, Turkey illegally closed its land border with Armenia in 1993. It has not lifted its blockade despite pressure from the powerful Turkish business lobby interested in Armenian markets.
On 10 October 2009, Armenia and Turkey signed protocols on normalisation of relationships, which set a timetable for restoring diplomatic ties and reopening their joint border. The ratification of those had to be made in the national parliaments. In Armenia it passed through the required by legislation approval of the Constitutional Court and was sent to the parliament for the final ratification. The President had made multiple public announcements, both in Armenia and abroad, that as the leader of the political majority of Armenia he assured the ratification of the protocols if Turkey also ratified them. Despite this, the process stopped, as Turkey continuously added more preconditions to its ratification and also "delayed it beyond any reasonable time-period".
Due to its position between two unfriendly neighbours, Armenia has close security ties with Russia. At the request of the Armenian government, Russia maintains a military base in the northwestern Armenian city of Gyumri as a deterrent against Turkey.[citation needed] Despite this, Armenia has also been looking toward Euro-Atlantic structures in recent years. It maintains good relations with the United States especially through its Armenian diaspora. According to the US Census Bureau, there are 427,822 Armenians living in the country.
Armenia is also a member of the Council of Europe, maintaining friendly relations with the European Union, especially with its member states such as France and Greece. A 2005 survey reported that 64% of Armenia's population would be in favor of joining the EU. Several Armenian officials have also expressed the desire for their country to eventually become an EU member state, some[who?] predicting that it will make an official bid for membership in a few years.[citation needed] In 2004 its forces joined KFOR, a NATO-led international force in Kosovo. It is also an observer member of the Eurasian Economic Community and the Non-Aligned Movement.
The Armenian Army, Air Force, Air Defence, and Border Guard comprise the four branches of the Armed Forces of the Republic of Armenia. The Armenian military was formed after the collapse of the Soviet Union in 1991 and with the establishment of the Ministry of Defence in 1992. The Commander-in-Chief of the military is the President of Armenia, Serzh Sargsyan. The Ministry of Defence is in charge of political leadership, currently headed by Colonel General Seyran Ohanyan, while military command remains in the hands of the General Staff, headed by the Chief of Staff, who is currently Colonel General Yuri Khatchaturov.
Armenia is member of Collective Security Treaty Organisation (CSTO) along with Belarus, Kazakhstan, Kyrgyzstan, Russia, Tajikistan and Uzbekistan. It participates in NATO's Partnership for Peace (PiP) program and is in a NATO organisation called Euro-Atlantic Partnership Council (EAPC). Armenia has engaged in a peacekeeping mission in Kosovo as part of non-NATO KFOR troops under Greek command. Armenia also had 46 members of its military peacekeeping forces as a part of the Coalition Forces in Iraq War until October 2008.
Within each province are communities (hamaynkner, singular hamaynk). Each community is self-governing and consists of one or more settlements (bnakavayrer, singular bnakavayr). Settlements are classified as either towns (kaghakner, singular kaghak) or villages (gyugher, singular gyugh). As of 2007[update], Armenia includes 915 communities, of which 49 are considered urban and 866 are considered rural. The capital, Yerevan, also has the status of a community. Additionally, Yerevan is divided into twelve semi-autonomous districts.
The economy relies heavily on investment and support from Armenians abroad. Before independence, Armenia's economy was largely industry-based – chemicals, electronics, machinery, processed food, synthetic rubber, and textile – and highly dependent on outside resources. The republic had developed a modern industrial sector, supplying machine tools, textiles, and other manufactured goods to sister republics in exchange for raw materials and energy. Recently, the Intel Corporation agreed to open a research center in Armenia, in addition to other technology companies, signalling the growth of the technology industry in Armenia.
Agriculture accounted for less than 20% of both net material product and total employment before the dissolution of the Soviet Union in 1991. After independence, the importance of agriculture in the economy increased markedly, its share at the end of the 1990s rising to more than 30% of GDP and more than 40% of total employment. This increase in the importance of agriculture was attributable to food security needs of the population in the face of uncertainty during the first phases of transition and the collapse of the non-agricultural sectors of the economy in the early 1990s. As the economic situation stabilized and growth resumed, the share of agriculture in GDP dropped to slightly over 20% (2006 data), although the share of agriculture in employment remained more than 40%.
Like other newly independent states of the former Soviet Union, Armenia's economy suffers from the breakdown of former Soviet trading patterns. Soviet investment in and support of Armenian industry has virtually disappeared, so that few major enterprises are still able to function. In addition, the effects of the 1988 Spitak earthquake, which killed more than 25,000 people and made 500,000 homeless, are still being felt. The conflict with Azerbaijan over Nagorno-Karabakh has not been resolved. The closure of Azerbaijani and Turkish borders has devastated the economy, because Armenia depends on outside supplies of energy and most raw materials. Land routes through Georgia and Iran are inadequate or unreliable. The GDP fell nearly 60% between 1989 and 1993, but then resumed robust growth. The national currency, the dram, suffered hyperinflation for the first years after its introduction in 1993.
Nevertheless, the government was able to make wide-ranging economic reforms that paid off in dramatically lower inflation and steady growth. The 1994 cease-fire in the Nagorno-Karabakh conflict has also helped the economy. Armenia has had strong economic growth since 1995, building on the turnaround that began the previous year, and inflation has been negligible for the past several years. New sectors, such as precious-stone processing and jewellery making, information and communication technology, and even tourism are beginning to supplement more traditional sectors of the economy, such as agriculture.
This steady economic progress has earned Armenia increasing support from international institutions. The International Monetary Fund (IMF), World Bank, European Bank for Reconstruction and Development (EBRD), and other international financial institutions (IFIs) and foreign countries are extending considerable grants and loans. Loans to Armenia since 1993 exceed $1.1 billion. These loans are targeted at reducing the budget deficit and stabilizing the currency; developing private businesses; energy; agriculture; food processing; transportation; the health and education sectors; and ongoing rehabilitation in the earthquake zone. The government joined the World Trade Organization on 5 February 2003. But one of the main sources of foreign direct investments remains the Armenian diaspora, which finances major parts of the reconstruction of infrastructure and other public projects. Being a growing democratic state, Armenia also hopes to get more financial aid from the Western World.
A liberal foreign investment law was approved in June 1994, and a law on privatisation was adopted in 1997, as well as a program of state property privatisation. Continued progress will depend on the ability of the government to strengthen its macroeconomic management, including increasing revenue collection, improving the investment climate, and making strides against corruption. However, unemployment, which currently stands at around 15%, still remains a major problem due to the influx of thousands of refugees from the Karabakh conflict.
In the 1988–89 school year, 301 students per 10,000 population were in specialized secondary or higher education, a figure slightly lower than the Soviet average. In 1989 some 58% of Armenians over age fifteen had completed their secondary education, and 14% had a higher education. In the 1990–91 school year, the estimated 1,307 primary and secondary schools were attended by 608,800 students. Another seventy specialized secondary institutions had 45,900 students, and 68,400 students were enrolled in a total of ten postsecondary institutions that included universities. In addition, 35% of eligible children attended preschools. In 1992 Armenia's largest institution of higher learning, Yerevan State University, had eighteen departments, including ones for social sciences, sciences, and law. Its faculty numbered about 1,300 teachers and its student population about 10,000 students. The National Polytechnic University of Armenia is operating since 1933.
On the basis of the expansion and development of Yerevan State University a number of higher educational independent Institutions were formed including Medical Institute separated in 1930 which was set up on the basis of medical faculty. In 1980 Yerevan State Medical University was awarded one of the main rewards of the former USSR – the Order of Labor red Banner for training qualified specialists in health care and valuable service in the development of Medical Science. In 1995 YSMI was renamed to YSMU and since 1989 it has been named after Mkhitar Heratsi, the famous medieval doctor. Mkhitar Heratsi was the founder of Armenian Medical school in Cilician Armenia. The great doctor played the same role in Armenian Medical Science as Hippocrates in Western, Galen in Roman, Ibn Sīnā in Arabic medicine.
Foreign students' department for Armenian diaspora established in 1957 later was enlarged and the enrollment of foreign students began. Nowadays the YSMU is a Medical Institution corresponding to international requirements, trains medical staff for not only Armenia and neighbor countries, i.e. Iran, Syria, Lebanon, Georgia, but also many other leading countries all over the world. A great number of foreign students from India, Nepal, Sri Lanka, the USA and Russian Federation study together with Armenian students. Nowadays the university is ranked among famous higher Medical Institutions and takes its honorable place in the World Directory of Medical Schools published by the WHO.
Other educational institutions in Armenia include the American University of Armenia and the QSI International School of Yerevan. The American University of Armenia has graduate programs in Business and Law, among others. The institution owes its existence to the combined efforts of the Government of Armenia, the Armenian General Benevolent Union, U.S. Agency for International Development, and the University of California. The extension programs and the library at AUA form a new focal point for English-language intellectual life in the city. Armenia also hosts a deployment of OLPC – One Laptopschool Per child XO laptop-tablet schools.
Instruments like the duduk, the dhol, the zurna, and the kanun are commonly found in Armenian folk music. Artists such as Sayat Nova are famous due to their influence in the development of Armenian folk music. One of the oldest types of Armenian music is the Armenian chant which is the most common kind of religious music in Armenia. Many of these chants are ancient in origin, extending to pre-Christian times, while others are relatively modern, including several composed by Saint Mesrop Mashtots, the inventor of the Armenian alphabet. Whilst under Soviet rule, Armenian classical music composer Aram Khatchaturian became internationally well known for his music, for various ballets and the Sabre Dance from his composition for the ballet Gayane.
The Armenian Genocide caused widespread emigration that led to the settlement of Armenians in various countries in the world. Armenians kept to their traditions and certain diasporans rose to fame with their music. In the post-Genocide Armenian community of the United States, the so-called "kef" style Armenian dance music, using Armenian and Middle Eastern folk instruments (often electrified/amplified) and some western instruments, was popular. This style preserved the folk songs and dances of Western Armenia, and many artists also played the contemporary popular songs of Turkey and other Middle Eastern countries from which the Armenians emigrated.
Richard Hagopian is perhaps the most famous artist of the traditional "kef" style and the Vosbikian Band was notable in the 1940s and 1950s for developing their own style of "kef music" heavily influenced by the popular American Big Band Jazz of the time. Later, stemming from the Middle Eastern Armenian diaspora and influenced by Continental European (especially French) pop music, the Armenian pop music genre grew to fame in the 1960s and 1970s with artists such as Adiss Harmandian and Harout Pamboukjian performing to the Armenian diaspora and Armenia; also with artists such as Sirusho, performing pop music combined with Armenian folk music in today's entertainment industry.
Other Armenian diasporans that rose to fame in classical or international music circles are world-renowned French-Armenian singer and composer Charles Aznavour, pianist Sahan Arzruni, prominent opera sopranos such as Hasmik Papian and more recently Isabel Bayrakdarian and Anna Kasyan. Certain Armenians settled to sing non-Armenian tunes such as the heavy metal band System of a Down (which nonetheless often incorporates traditional Armenian instrumentals and styling into their songs) or pop star Cher. In the Armenian diaspora, Armenian revolutionary songs are popular with the youth. These songs encourage Armenian patriotism and are generally about Armenian history and national heroes.
Yerevan Vernissage (arts and crafts market), close to Republic Square, bustles with hundreds of vendors selling a variety of crafts on weekends and Wednesdays (though the selection is much reduced mid-week). The market offers woodcarving, antiques, fine lace, and the hand-knotted wool carpets and kilims that are a Caucasus specialty. Obsidian, which is found locally, is crafted into assortment of jewellery and ornamental objects. Armenian gold smithery enjoys a long tradition, populating one corner of the market with a selection of gold items. Soviet relics and souvenirs of recent Russian manufacture – nesting dolls, watches, enamel boxes and so on – are also available at the Vernisage.
The National Art Gallery in Yerevan has more than 16,000 works that date back to the Middle Ages, which indicate Armenia's rich tales and stories of the times. It houses paintings by many European masters as well. The Modern Art Museum, the Children’s Picture Gallery, and the Martiros Saryan Museum are only a few of the other noteworthy collections of fine art on display in Yerevan. Moreover, many private galleries are in operation, with many more opening every year, featuring rotating exhibitions and sales.
A wide array of sports are played in Armenia, the most popular among them being wrestling, weightlifting, judo, association football, chess, and boxing. Armenia's mountainous terrain provides great opportunities for the practice of sports like skiing and climbing. Being a landlocked country, water sports can only be practiced on lakes, notably Lake Sevan. Competitively, Armenia has been successful in chess, weightlifting and wrestling at the international level. Armenia is also an active member of the international sports community, with full membership in the Union of European Football Associations (UEFA) and International Ice Hockey Federation (IIHF). It also hosts the Pan-Armenian Games.
Prior to 1992, Armenians would participate in the Olympics representing the USSR. As part of the Soviet Union, Armenia was very successful, winning plenty of medals and helping the USSR win the medal standings at the Olympics on numerous occasions. The first medal won by an Armenian in modern Olympic history was by Hrant Shahinyan (sometimes spelled as Grant Shaginyan), who won two golds and two silvers in gymnastics at the 1952 Summer Olympics in Helsinki. To highlight the level of success of Armenians in the Olympics, Shahinyan was quoted as saying:
Football is also popular in Armenia. The most successful team was the FC Ararat Yerevan team of the 1970s who won the Soviet Cup in 1973 and 1975 and the Soviet Top League in 1973. The latter achievement saw FC Ararat gain entry to the European Cup where – despite a home victory in the second leg – they lost on aggregate at the quarter final stage to eventual winner FC Bayern Munich. Armenia competed internationally as part of the USSR national football team until the Armenian national football team was formed in 1992 after the split of the Soviet Union. Armenia have never qualified for a major tournament although recent improvements saw the team to achieve 44th position in the FIFA World Rankings in September 2011. The national team is controlled by the Football Federation of Armenia. The Armenian Premier League is the highest level football competition in Armenia, and has been dominated by FC Pyunik in recent seasons. The league currently consists of eight teams and relegates to the Armenian First League.
Due to the lack of success lately on the international level, in recent years, Armenia has rebuilt 16 Soviet-era sports schools and furnished them with new equipment for a total cost of $1.9 million. The rebuilding of the regional schools was financed by the Armenian government. $9.3 million has been invested in the resort town of Tsaghkadzor to improve the winter sports infrastructure because of dismal performances at recent winter sports events. In 2005, a cycling center was opened in Yerevan with the aim of helping produce world class Armenian cyclists. The government has also promised a cash reward of $700,000 to Armenians who win a gold medal at the Olympics.
Armenian cuisine is as ancient as the history of Armenia, a combination of different tastes and aromas. The food often has quite a distinct aroma. Closely related to eastern and Mediterranean cuisine, various spices, vegetables, fish, and fruits combine to present unique dishes. The main characteristics of Armenian cuisine are a reliance on the quality of the ingredients rather than heavily spicing food, the use of herbs, the use of wheat in a variety of forms, of legumes, nuts, and fruit (as a main ingredient as well as to sour food), and the stuffing of a wide variety of leaves.
Bacteria (i/bækˈtɪəriə/; singular: bacterium) constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep portions of Earth's crust. Bacteria also live in symbiotic and parasitic relationships with plants and animals. They are also known to have flourished in manned spacecraft.
There are typically 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water. There are approximately 5×1030 bacteria on Earth, forming a biomass which exceeds that of all plants and animals. Bacteria are vital in recycling nutrients, with many of the stages in nutrient cycles dependent on these organisms, such as the fixation of nitrogen from the atmosphere and putrefaction. In the biological communities surrounding hydrothermal vents and cold seeps, bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. On 17 March 2013, researchers reported data that suggested bacterial life forms thrive in the Mariana Trench, which with a depth of up to 11 kilometres is the deepest part of the Earth's oceans. Other researchers reported related studies that microbes thrive inside rocks up to 580 metres below the sea floor under 2.6 kilometres of ocean off the coast of the northwestern United States. According to one of the researchers, "You can find microbes everywhere — they're extremely adaptable to conditions, and survive wherever they are."
There are approximately ten times as many bacterial cells in the human flora as there are human cells in the body, with the largest number of the human flora being in the gut flora, and a large number on the skin. The vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system, and some are beneficial. However, several species of bacteria are pathogenic and cause infectious diseases, including cholera, syphilis, anthrax, leprosy, and bubonic plague. The most common fatal bacterial diseases are respiratory infections, with tuberculosis alone killing about 2 million people per year, mostly in sub-Saharan Africa. In developed countries, antibiotics are used to treat bacterial infections and are also used in farming, making antibiotic resistance a growing problem. In industry, bacteria are important in sewage treatment and the breakdown of oil spills, the production of cheese and yogurt through fermentation, and the recovery of gold, palladium, copper and other metals in the mining sector, as well as in biotechnology, and the manufacture of antibiotics and other chemicals.
Once regarded as plants constituting the class Schizomycetes, bacteria are now classified as prokaryotes. Unlike cells of animals and other eukaryotes, bacterial cells do not contain a nucleus and rarely harbour membrane-bound organelles. Although the term bacteria traditionally included all prokaryotes, the scientific classification changed after the discovery in the 1990s that prokaryotes consist of two very different groups of organisms that evolved from an ancient common ancestor. These evolutionary domains are called Bacteria and Archaea.
The ancestors of modern bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, about 4 billion years ago. For about 3 billion years, most organisms were microscopic, and bacteria and archaea were the dominant forms of life. In 2008, fossils of macroorganisms were discovered and named as the Francevillian biota. Although bacterial fossils exist, such as stromatolites, their lack of distinctive morphology prevents them from being used to examine the history of bacterial evolution, or to date the time of origin of a particular bacterial species. However, gene sequences can be used to reconstruct the bacterial phylogeny, and these studies indicate that bacteria diverged first from the archaeal/eukaryotic lineage. Bacteria were also involved in the second great evolutionary divergence, that of the archaea and eukaryotes. Here, eukaryotes resulted from the entering of ancient bacteria into endosymbiotic associations with the ancestors of eukaryotic cells, which were themselves possibly related to the Archaea. This involved the engulfment by proto-eukaryotic cells of alphaproteobacterial symbionts to form either mitochondria or hydrogenosomes, which are still found in all known Eukarya (sometimes in highly reduced form, e.g. in ancient "amitochondrial" protozoa). Later on, some eukaryotes that already contained mitochondria also engulfed cyanobacterial-like organisms. This led to the formation of chloroplasts in algae and plants. There are also some algae that originated from even later endosymbiotic events. Here, eukaryotes engulfed a eukaryotic algae that developed into a "second-generation" plastid. This is known as secondary endosymbiosis.
Bacteria display a wide diversity of shapes and sizes, called morphologies. Bacterial cells are about one-tenth the size of eukaryotic cells and are typically 0.5–5.0 micrometres in length. However, a few species are visible to the unaided eye — for example, Thiomargarita namibiensis is up to half a millimetre long and Epulopiscium fishelsoni reaches 0.7 mm. Among the smallest bacteria are members of the genus Mycoplasma, which measure only 0.3 micrometres, as small as the largest viruses. Some bacteria may be even smaller, but these ultramicrobacteria are not well-studied.
Most bacterial species are either spherical, called cocci (sing. coccus, from Greek kókkos, grain, seed), or rod-shaped, called bacilli (sing. bacillus, from Latin baculus, stick). Elongation is associated with swimming. Some bacteria, called vibrio, are shaped like slightly curved rods or comma-shaped; others can be spiral-shaped, called spirilla, or tightly coiled, called spirochaetes. A small number of species even have tetrahedral or cuboidal shapes. More recently, some bacteria were discovered deep under Earth's crust that grow as branching filamentous types with a star-shaped cross-section. The large surface area to volume ratio of this morphology may give these bacteria an advantage in nutrient-poor environments. This wide variety of shapes is determined by the bacterial cell wall and cytoskeleton, and is important because it can influence the ability of bacteria to acquire nutrients, attach to surfaces, swim through liquids and escape predators.
Many bacterial species exist simply as single cells, others associate in characteristic patterns: Neisseria form diploids (pairs), Streptococcus form chains, and Staphylococcus group together in "bunch of grapes" clusters. Bacteria can also be elongated to form filaments, for example the Actinobacteria. Filamentous bacteria are often surrounded by a sheath that contains many individual cells. Certain types, such as species of the genus Nocardia, even form complex, branched filaments, similar in appearance to fungal mycelia.
Bacteria often attach to surfaces and form dense aggregations called biofilms or bacterial mats. These films can range from a few micrometers in thickness to up to half a meter in depth, and may contain multiple species of bacteria, protists and archaea. Bacteria living in biofilms display a complex arrangement of cells and extracellular components, forming secondary structures, such as microcolonies, through which there are networks of channels to enable better diffusion of nutrients. In natural environments, such as soil or the surfaces of plants, the majority of bacteria are bound to surfaces in biofilms. Biofilms are also important in medicine, as these structures are often present during chronic bacterial infections or in infections of implanted medical devices, and bacteria protected within biofilms are much harder to kill than individual isolated bacteria.
Even more complex morphological changes are sometimes possible. For example, when starved of amino acids, Myxobacteria detect surrounding cells in a process known as quorum sensing, migrate toward each other, and aggregate to form fruiting bodies up to 500 micrometres long and containing approximately 100,000 bacterial cells. In these fruiting bodies, the bacteria perform separate tasks; this type of cooperation is a simple type of multicellular organisation. For example, about one in 10 cells migrate to the top of these fruiting bodies and differentiate into a specialised dormant state called myxospores, which are more resistant to drying and other adverse environmental conditions than are ordinary cells.
The bacterial cell is surrounded by a cell membrane (also known as a lipid, cytoplasmic or plasma membrane). This membrane encloses the contents of the cell and acts as a barrier to hold nutrients, proteins and other essential components of the cytoplasm within the cell. As they are prokaryotes, bacteria do not usually have membrane-bound organelles in their cytoplasm, and thus contain few large intracellular structures. They lack a true nucleus, mitochondria, chloroplasts and the other organelles present in eukaryotic cells. Bacteria were once seen as simple bags of cytoplasm, but structures such as the prokaryotic cytoskeleton and the localization of proteins to specific locations within the cytoplasm that give bacteria some complexity have been discovered. These subcellular levels of organization have been called "bacterial hyperstructures".
Many important biochemical reactions, such as energy generation, use concentration gradients across membranes. The general lack of internal membranes in bacteria means reactions such as electron transport occur across the cell membrane between the cytoplasm and the periplasmic space. However, in many photosynthetic bacteria the plasma membrane is highly folded and fills most of the cell with layers of light-gathering membrane. These light-gathering complexes may even form lipid-enclosed structures called chlorosomes in green sulfur bacteria. Other proteins import nutrients across the cell membrane, or expel undesired molecules from the cytoplasm.
Bacteria do not have a membrane-bound nucleus, and their genetic material is typically a single circular DNA chromosome located in the cytoplasm in an irregularly shaped body called the nucleoid. The nucleoid contains the chromosome with its associated proteins and RNA. The phylum Planctomycetes and candidate phylum Poribacteria may be exceptions to the general absence of internal membranes in bacteria, because they appear to have a double membrane around their nucleoids and contain other membrane-bound cellular structures. Like all living organisms, bacteria contain ribosomes, often grouped in chains called polyribosomes, for the production of proteins, but the structure of the bacterial ribosome is different from that of eukaryotes and Archaea. Bacterial ribosomes have a sedimentation rate of 70S (measured in Svedberg units): their subunits have rates of 30S and 50S. Some antibiotics bind specifically to 70S ribosomes and inhibit bacterial protein synthesis. Those antibiotics kill bacteria without affecting the larger 80S ribosomes of eukaryotic cells and without harming the host.
Some bacteria produce intracellular nutrient storage granules for later use, such as glycogen, polyphosphate, sulfur or polyhydroxyalkanoates. Certain bacterial species, such as the photosynthetic Cyanobacteria, produce internal gas vesicles, which they use to regulate their buoyancy – allowing them to move up or down into water layers with different light intensities and nutrient levels. Intracellular membranes called chromatophores are also found in membranes of phototrophic bacteria. Used primarily for photosynthesis, they contain bacteriochlorophyll pigments and carotenoids. An early idea was that bacteria might contain membrane folds termed mesosomes, but these were later shown to be artifacts produced by the chemicals used to prepare the cells for electron microscopy. Inclusions are considered to be nonliving components of the cell that do not possess metabolic activity and are not bounded by membranes. The most common inclusions are glycogen, lipid droplets, crystals, and pigments. Volutin granules are cytoplasmic inclusions of complexed inorganic polyphosphate. These granules are called metachromatic granules due to their displaying the metachromatic effect; they appear red or blue when stained with the blue dyes methylene blue or toluidine blue. Gas vacuoles, which are freely permeable to gas, are membrane-bound vesicles present in some species of Cyanobacteria. They allow the bacteria to control their buoyancy. Microcompartments are widespread, membrane-bound organelles that are made of a protein shell that surrounds and encloses various enzymes. Carboxysomes are bacterial microcompartments that contain enzymes involved in carbon fixation. Magnetosomes are bacterial microcompartments, present in magnetotactic bacteria, that contain magnetic crystals.
In most bacteria, a cell wall is present on the outside of the cell membrane. The cell membrane and cell wall comprise the cell envelope. A common bacterial cell wall material is peptidoglycan (called "murein" in older sources), which is made from polysaccharide chains cross-linked by peptides containing D-amino acids. Bacterial cell walls are different from the cell walls of plants and fungi, which are made of cellulose and chitin, respectively. The cell wall of bacteria is also distinct from that of Archaea, which do not contain peptidoglycan. The cell wall is essential to the survival of many bacteria, and the antibiotic penicillin is able to kill bacteria by inhibiting a step in the synthesis of peptidoglycan.
Gram-positive bacteria possess a thick cell wall containing many layers of peptidoglycan and teichoic acids. In contrast, gram-negative bacteria have a relatively thin cell wall consisting of a few layers of peptidoglycan surrounded by a second lipid membrane containing lipopolysaccharides and lipoproteins. Lipopolysaccharides, also called endotoxins, are composed of polysaccharides and lipid A that is responsible for much of the toxicity of gram-negative bacteria. Most bacteria have the gram-negative cell wall, and only the Firmicutes and Actinobacteria have the alternative gram-positive arrangement. These two groups were previously known as the low G+C and high G+C Gram-positive bacteria, respectively. These differences in structure can produce differences in antibiotic susceptibility; for instance, vancomycin can kill only gram-positive bacteria and is ineffective against gram-negative pathogens, such as Haemophilus influenzae or Pseudomonas aeruginosa. If the bacterial cell wall is entirely removed, it is called a protoplast, whereas if it is partially removed, it is called a spheroplast. β-Lactam antibiotics, such as penicillin, inhibit the formation of peptidoglycan cross-links in the bacterial cell wall. The enzyme lysozyme, found in human tears, also digests the cell wall of bacteria and is the body's main defense against eye infections.
Acid-fast bacteria, such as Mycobacteria, are resistant to decolorization by acids during staining procedures. The high mycolic acid content of Mycobacteria, is responsible for the staining pattern of poor absorption followed by high retention. The most common staining technique used to identify acid-fast bacteria is the Ziehl-Neelsen stain or acid-fast stain, in which the acid-fast bacilli are stained bright-red and stand out clearly against a blue background. L-form bacteria are strains of bacteria that lack cell walls. The main pathogenic bacteria in this class is Mycoplasma (not to be confused with Mycobacteria).
Fimbriae (sometimes called "attachment pili") are fine filaments of protein, usually 2–10 nanometres in diameter and up to several micrometers in length. They are distributed over the surface of the cell, and resemble fine hairs when seen under the electron microscope. Fimbriae are believed to be involved in attachment to solid surfaces or to other cells, and are essential for the virulence of some bacterial pathogens. Pili (sing. pilus) are cellular appendages, slightly larger than fimbriae, that can transfer genetic material between bacterial cells in a process called conjugation where they are called conjugation pili or "sex pili" (see bacterial genetics, below). They can also generate movement where they are called type IV pili (see movement, below).
Certain genera of Gram-positive bacteria, such as Bacillus, Clostridium, Sporohalobacter, Anaerobacter, and Heliobacterium, can form highly resistant, dormant structures called endospores. In almost all cases, one endospore is formed and this is not a reproductive process, although Anaerobacter can make up to seven endospores in a single cell. Endospores have a central core of cytoplasm containing DNA and ribosomes surrounded by a cortex layer and protected by an impermeable and rigid coat. Dipicolinic acid is a chemical compound that composes 5% to 15% of the dry weight of bacterial spores. It is implicated as responsible for the heat resistance of the endospore.
Endospores show no detectable metabolism and can survive extreme physical and chemical stresses, such as high levels of UV light, gamma radiation, detergents, disinfectants, heat, freezing, pressure, and desiccation. In this dormant state, these organisms may remain viable for millions of years, and endospores even allow bacteria to survive exposure to the vacuum and radiation in space. According to scientist Dr. Steinn Sigurdsson, "There are viable bacterial spores that have been found that are 40 million years old on Earth — and we know they're very hardened to radiation." Endospore-forming bacteria can also cause disease: for example, anthrax can be contracted by the inhalation of Bacillus anthracis endospores, and contamination of deep puncture wounds with Clostridium tetani endospores causes tetanus.
Bacteria exhibit an extremely wide variety of metabolic types. The distribution of metabolic traits within a group of bacteria has traditionally been used to define their taxonomy, but these traits often do not correspond with modern genetic classifications. Bacterial metabolism is classified into nutritional groups on the basis of three major criteria: the kind of energy used for growth, the source of carbon, and the electron donors used for growth. An additional criterion of respiratory microorganisms are the electron acceptors used for aerobic or anaerobic respiration.
Carbon metabolism in bacteria is either heterotrophic, where organic carbon compounds are used as carbon sources, or autotrophic, meaning that cellular carbon is obtained by fixing carbon dioxide. Heterotrophic bacteria include parasitic types. Typical autotrophic bacteria are phototrophic cyanobacteria, green sulfur-bacteria and some purple bacteria, but also many chemolithotrophic species, such as nitrifying or sulfur-oxidising bacteria. Energy metabolism of bacteria is either based on phototrophy, the use of light through photosynthesis, or based on chemotrophy, the use of chemical substances for energy, which are mostly oxidised at the expense of oxygen or alternative electron acceptors (aerobic/anaerobic respiration).
Bacteria are further divided into lithotrophs that use inorganic electron donors and organotrophs that use organic compounds as electron donors. Chemotrophic organisms use the respective electron donors for energy conservation (by aerobic/anaerobic respiration or fermentation) and biosynthetic reactions (e.g., carbon dioxide fixation), whereas phototrophic organisms use them only for biosynthetic purposes. Respiratory organisms use chemical compounds as a source of energy by taking electrons from the reduced substrate and transferring them to a terminal electron acceptor in a redox reaction. This reaction releases energy that can be used to synthesise ATP and drive metabolism. In aerobic organisms, oxygen is used as the electron acceptor. In anaerobic organisms other inorganic compounds, such as nitrate, sulfate or carbon dioxide are used as electron acceptors. This leads to the ecologically important processes of denitrification, sulfate reduction, and acetogenesis, respectively.
These processes are also important in biological responses to pollution; for example, sulfate-reducing bacteria are largely responsible for the production of the highly toxic forms of mercury (methyl- and dimethylmercury) in the environment. Non-respiratory anaerobes use fermentation to generate energy and reducing power, secreting metabolic by-products (such as ethanol in brewing) as waste. Facultative anaerobes can switch between fermentation and different terminal electron acceptors depending on the environmental conditions in which they find themselves.
Lithotrophic bacteria can use inorganic compounds as a source of energy. Common inorganic electron donors are hydrogen, carbon monoxide, ammonia (leading to nitrification), ferrous iron and other reduced metal ions, and several reduced sulfur compounds. In unusual circumstances, the gas methane can be used by methanotrophic bacteria as both a source of electrons and a substrate for carbon anabolism. In both aerobic phototrophy and chemolithotrophy, oxygen is used as a terminal electron acceptor, whereas under anaerobic conditions inorganic compounds are used instead. Most lithotrophic organisms are autotrophic, whereas organotrophic organisms are heterotrophic.
Regardless of the type of metabolic process they employ, the majority of bacteria are able to take in raw materials only in the form of relatively small molecules, which enter the cell by diffusion or through molecular channels in cell membranes. The Planctomycetes are the exception (as they are in possessing membranes around their nuclear material). It has recently been shown that Gemmata obscuriglobus is able to take in large molecules via a process that in some ways resembles endocytosis, the process used by eukaryotic cells to engulf external items.
Unlike in multicellular organisms, increases in cell size (cell growth) and reproduction by cell division are tightly linked in unicellular organisms. Bacteria grow to a fixed size and then reproduce through binary fission, a form of asexual reproduction. Under optimal conditions, bacteria can grow and divide extremely rapidly, and bacterial populations can double as quickly as every 9.8 minutes. In cell division, two identical clone daughter cells are produced. Some bacteria, while still reproducing asexually, form more complex reproductive structures that help disperse the newly formed daughter cells. Examples include fruiting body formation by Myxobacteria and aerial hyphae formation by Streptomyces, or budding. Budding involves a cell forming a protrusion that breaks away and produces a daughter cell.
In the laboratory, bacteria are usually grown using solid or liquid media. Solid growth media, such as agar plates, are used to isolate pure cultures of a bacterial strain. However, liquid growth media are used when measurement of growth or large volumes of cells are required. Growth in stirred liquid media occurs as an even cell suspension, making the cultures easy to divide and transfer, although isolating single bacteria from liquid media is difficult. The use of selective media (media with specific nutrients added or deficient, or with antibiotics added) can help identify specific organisms.
Most laboratory techniques for growing bacteria use high levels of nutrients to produce large amounts of cells cheaply and quickly. However, in natural environments, nutrients are limited, meaning that bacteria cannot continue to reproduce indefinitely. This nutrient limitation has led the evolution of different growth strategies (see r/K selection theory). Some organisms can grow extremely rapidly when nutrients become available, such as the formation of algal (and cyanobacterial) blooms that often occur in lakes during the summer. Other organisms have adaptations to harsh environments, such as the production of multiple antibiotics by Streptomyces that inhibit the growth of competing microorganisms. In nature, many organisms live in communities (e.g., biofilms) that may allow for increased supply of nutrients and protection from environmental stresses. These relationships can be essential for growth of a particular organism or group of organisms (syntrophy).
Bacterial growth follows four phases. When a population of bacteria first enter a high-nutrient environment that allows growth, the cells need to adapt to their new environment. The first phase of growth is the lag phase, a period of slow growth when the cells are adapting to the high-nutrient environment and preparing for fast growth. The lag phase has high biosynthesis rates, as proteins necessary for rapid growth are produced. The second phase of growth is the log phase, also known as the logarithmic or exponential phase. The log phase is marked by rapid exponential growth. The rate at which cells grow during this phase is known as the growth rate (k), and the time it takes the cells to double is known as the generation time (g). During log phase, nutrients are metabolised at maximum speed until one of the nutrients is depleted and starts limiting growth. The third phase of growth is the stationary phase and is caused by depleted nutrients. The cells reduce their metabolic activity and consume non-essential cellular proteins. The stationary phase is a transition from rapid growth to a stress response state and there is increased expression of genes involved in DNA repair, antioxidant metabolism and nutrient transport. The final phase is the death phase where the bacteria run out of nutrients and die.
Most bacteria have a single circular chromosome that can range in size from only 160,000 base pairs in the endosymbiotic bacteria Candidatus Carsonella ruddii, to 12,200,000 base pairs in the soil-dwelling bacteria Sorangium cellulosum. Spirochaetes of the genus Borrelia are a notable exception to this arrangement, with bacteria such as Borrelia burgdorferi, the cause of Lyme disease, containing a single linear chromosome. The genes in bacterial genomes are usually a single continuous stretch of DNA and although several different types of introns do exist in bacteria, these are much rarer than in eukaryotes.
Bacteria, as asexual organisms, inherit identical copies of their parent's genes (i.e., they are clonal). However, all bacteria can evolve by selection on changes to their genetic material DNA caused by genetic recombination or mutations. Mutations come from errors made during the replication of DNA or from exposure to mutagens. Mutation rates vary widely among different species of bacteria and even among different clones of a single species of bacteria. Genetic changes in bacterial genomes come from either random mutation during replication or "stress-directed mutation", where genes involved in a particular growth-limiting process have an increased mutation rate.
Transduction of bacterial genes by bacteriophage appears to be a consequence of infrequent errors during intracellular assembly of virus particles, rather than a bacterial adaptation. Conjugation, in the much-studied E. coli system is determined by plasmid genes, and is an adaptation for transferring copies of the plasmid from one bacterial host to another. It is seldom that a conjugative plasmid integrates into the host bacterial chromosome, and subsequently transfers part of the host bacterial DNA to another bacterium. Plasmid-mediated transfer of host bacterial DNA also appears to be an accidental process rather than a bacterial adaptation.
Transformation, unlike transduction or conjugation, depends on numerous bacterial gene products that specifically interact to perform this complex process, and thus transformation is clearly a bacterial adaptation for DNA transfer. In order for a bacterium to bind, take up and recombine donor DNA into its own chromosome, it must first enter a special physiological state termed competence (see Natural competence). In Bacillus subtilis, about 40 genes are required for the development of competence. The length of DNA transferred during B. subtilis transformation can be between a third of a chromosome up to the whole chromosome. Transformation appears to be common among bacterial species, and thus far at least 60 species are known to have the natural ability to become competent for transformation. The development of competence in nature is usually associated with stressful environmental conditions, and seems to be an adaptation for facilitating repair of DNA damage in recipient cells.

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