Richard Leakey (19 December 1944 – 2 January 2022) was a Kenyan politician,  paleoanthropologist and conservationist. He was second of the three sons of the anthropologists Louis Leakey and Mary Leakey. In 2007, he was elected a Fellow of the Royal Society.

Early life
A high school dropout, Leakey discovered his love of paleontology when he led an expedition to a fossil site he had discovered while flying.  Frustrated by the lack of recognition he received for his accomplishments (due to his lack of qualifications), Leakey left for England to catch up on his education. However, after six months, Leakey returned home to continue his safaris.  He never completed his degree.

In 1965 he married Margaret Cropper. Their daughter Anna was born in 1969, the same year that Richard and Margaret divorced. He then married his colleague Meave Epps in 1970. They had two daughters, Louise (born 1972) and Samira (1974).

Leakey was diagnosed with a terminal kidney disease in 1969. Ten years later he became seriously ill, but received a kidney transplant from his brother Philip and recovered to full health.

In 1993, a small propeller-driven plane piloted by Richard Leakey crashed, crushing his lower legs. Both legs were later amputated. Sabotage was suspected but never proved. In a few months Richard Leakey was walking again on artificial limbs.

Leakey said in his autobiography that he was an atheist.

Teenage entrepreneur
Richard chose to support himself. He borrowed 500 pounds from his parents for a Land Rover, and went into the trapping and skeleton supply business with Kamoya Kimeu.

Richard was already a skilled horseman, outdoorsman, Land Rover mechanic, archaeologist and expedition leader. He learned to identify bones. All these skills pointed to a path he did not yet wish to take, simply because his father was on it.

The bone business turned into a safari business in 1961. In 1962 he got a private airplane pilot licence and took tours to Olduvai. It was from a casual aerial survey that he noted the potential of Lake Natron's shores for paleontology. He went looking for fossils in a Land Rover, but could find none, until his parents assigned Glynn Isaac to go with him.

Louis was so impressed with their finds that he gave them National Geographic money for a month's expedition.chapter 18 They explored in the vicinity of Peninj near the lake, where Richard was in charge of the administrative details. Bored, he returned to Nairobi temporarily, but at that moment, Kamoya Kimeu discovered a fossil of Australopithecus boisei. A second expedition left Richard feeling that he was being excluded from the most significant part of the operation, the scientific analysis.

Expeditions led by Richard Leakey

Koobi Fora
During the Omo expedition of 1967, Richard visited Nairobi and on the return flight the pilot flew over Lake Rudolph (now Lake Turkana) to avoid a thunderstorm. The map led Richard to expect volcanic rock below him but he saw sediments. Visiting the region by helicopter, he saw tools and fossils everywhere. In his mind, he was already planning a new enterprise.

In 1969 the discovery of a cranium of Paranthropus boisei caused great excitement. A Homo habilis skull and a Homo erectus skull, discovered in 1972 and 1975, respectively, were among the most significant finds of Leakey's earlier expeditions. In 1978 an intact cranium of Homo erectus was discovered.

Leakey and Donald Johanson were at the time considered to be the most famous palaeoanthoropologists, and scientifically their views on human evolution were differing, a scientific rivalry that gained public attention. This culminated at the Cronkite's Universe talk show hosted by Walter Cronkite in New York in 1981, where Leakey and Johanson held a fierce debate on live TV show.

West Turkana
Turkana Boy — discovered by Kamoya Kimeu, a member of the Leakeys' team in 1984 — was the nearly complete skeleton of a Homo ergaster (though some, including Leakey, call it erectus) who died 1.6 million years ago at about age 9-12.

Leakey and Roger Lewin describe the experience of this find and their interpretation of it, in their book Origins reconsidered (1992).  Shortly after the discovery of Turkana Boy, Leakey and his team made the discovery of a skull (known as 'Black Skull') of a new species, Australopithecus aethiopicus (or Paranthropus aethiopicus).

Richard shifted away from paleontology in 1989, but his wife Meave Leakey and daughter Louise Leakey still continue paleontological research in Northern Kenya.

Conservation

In 1989 Richard Leakey was appointed the head of the Wildlife Conservation and Management Department (WMCD) by President Daniel Arap Moi in response to the international outcry over the poaching of elephants and the impact it was having on the wildlife of Kenya.

The department was replaced by Kenya Wildlife Service (KWS) in 1990, and Leakey became its first chairman. With characteristically bold steps Leakey created special, well-armed anti-poaching units that were authorized to shoot poachers on sight. The poaching menace was dramatically reduced. Impressed by Leakey's transformation of the KWS, the World Bank approved grants worth $140 million. Richard Leakey, President Arap Moi and the WMCD made the international news headlines when a stockpile of 12 tons of ivory was burned in 1989 in Nairobi National Park.

Richard Leakey wrote about his experiences at the KWS in his book Wildlife Wars: my battle to save Kenya's elephants (2001).

Politics
In May 1995 Richard Leakey joined a group of Kenyan intellectuals in launching a new political party — the Safina Party, which in Swahili means "Noah's Ark".

"If KANU and Mr. Moi will do something about the deterioration of public life, corruption and mismanagement, I'd be happy to fight alongside them. If they won't, I want somebody else to do it," announced Richard Leakey. The Safina party was routinely harassed and even its application to become an official political party was not approved until 1997.

In 1999, Moi appointed Richard Leakey as Cabinet Secretary and overall head of the civil service. Moi's hand was forced: the international donor institutions insisted as a pre-condition for the resumption of donor funds. Leakey's second stint in the civil service lasted until 2001 when he was forced to resign again.

Later activities
Leakey joined the Department of Anthropology faculty at Stony Brook University, New York in 2002. He is currently a Professor of Anthropology at Stony Brook, where he is Chair of the Turkana Basin Institute.

In 2004, Richard Leakey founded and chaired WildlifeDirect, a Kenya-based charitable organization. The charity was established to provide support to conservationists in Africa directly on the ground via the use of blogs. This enables individuals anywhere to play a direct and interactive role in the survival of some of the world's most precious species.  The organization played a significant role in the saving of Congo's mountain gorillas in Virunga National Park in January 2007 after a rebel uprising threatened to eliminate the highly vulnerable population.

In April 2007 he was appointed interim chairman of Transparency International, Kenya branch.

Death
Leakey died on 2 January 2022 at his home near Nairobi at the age of 77.

Family tree

References

1944 births
2022 deaths
Anthropologists
Paleontologists
Atheists
People from Nairobi
Autobiographers
Civil servants
Leakey family

Richard Leakey


Emporio or Emporeio (), also known as Nimborios (), is a village on the island of Santorini, Greece. It is located 12 km from Fira, near the Profitis Ilias Mountains.

According to the 2011 census, the community of Emporio has 3,085 permanent inhabitants. The community consists of the villages Emporeio, Perissa, Agios Georgios and Exomytis.

Among other attractions, Emporio boasts the old Goulas Castle and some churches, such as Saint Nicholas Marmaritis.

References

Emporio

Santorini
Populated places in Thira (regional unit)

Emporio, Santorini


Troilus and Cressida is a play by William Shakespeare. It is a tragedy. Shakespeare's sources were probably Greek mythology, and also the works of Homer and Geoffrey Chaucer. The first known performance was on 7 February 1604. The first known printing of the play dates to 1609. The play is about the Trojan War and two lovers, Troilus and Cressida.

Plays by William Shakespeare
1600s plays

Troilus and Cressida


The Köppen climate classification is one of the most widely used climate classification systems.  It was developed by Wladimir Köppen, a German climatologist, around 1900 (with several further modifications by himself, notably in 1918 and 1936).  It is based on the concept that native vegetation is the best expression of climate, thus climate zone boundaries have been selected with vegetation distribution in mind.

System
Group A is tropical. The average temperature in the coolest month must be at least 18° C.
Group B is arid - desert and steppe/semi-arid. The average precipitation must be less than a certain amount that depends on the temperature.
Group C is mesothermal, the subtropical and temperate climates. The warmest months must have an average greater than 10° C and the coldest month must have a temperature between 0 or -3° C and 18° C. This group includes humid subtropical, Mediterranean, highland, and oceanic.
Group D is microthermal or continental (hot/warm summers and cold winters) and subarctic (short warm summers and cold winters). The warmest months must have an average greater than 10° C and the coldest months must have an average of less than 0 or -3° C.
Group E is polar and alpine. The warmest month must have an average temperature less than 10° C.

Related pages
 Climatology

References

Climate

Köppen climate classification


Laissez-faire is short for, "laissez-faire, laissez-passer," a French phrase meanin idiomatically "leave tae dae, leave tae pass" or mair accurate "lat things abee, lat thaim pass". First uised bi the aichteent century Physiocrats as an injunction agin govrenment interficherin wi tred an troke, it is nou uised as a synonym for strict free mercat economics. Laissez-faire economic policy is in direct contrast tae statist economic policy. Adam Smith played a lairge role in popularizin laissez-faire economic theories in Inglis-speakin kintras, thou he wis tuithie o a nummer o aspects o whit is currently thocht o as laissez-faire (sic as want o govrenment regulation o business practices).

Laissez-faire (imperative) is distinct frae laisser faire (infinitive) that refers tae a careless attitude in the application o a policy, impleein a want o conseederation, or thocht.

Economics

Laissez-faire


Nation Radio Scotland  (formerly XFM Scotland (2014), 96.3 Rock Radio  Real XS, Q96 and 96.3QFM) is a Scottish Independent Local Radio station for Renfrewshire, Glasgow and West Central Scotland, owned by Nation Broadcasting.

As of September 2023, the station broadcasts to a weekly audience of 120,000, according to RAJAR.

History
The station launched in January 2007 as 96.3 Rock Radio, a classic rock station owned by GMG Radio who had bought the licence previously owned by UTV Radio and branded as Q96, a mainstream music station. The station shared news and sport coverage with associated stations Real Radio and Smooth Radio but carried emphasis on Renfrewshire issues to fulfill its licensing requirement, such as lead sport stories from St Mirren.

On 28 July 2011 it was announced that GMG Radio would be rebranding sister station 106.1 Rock Radio as Real Radio XS for its Manchester audience. Around the same time, the managing director announced his departure from the station and entered talks with GMG Radio on buying out the station along with a group of private investors. Two months later, GMG announced the station would not be sold off and would be rebranded as '96.3 Real Radio XS' at the end of October 2011.

Following the sale of GMG Radio to Global Radio, and the resulting sale of several stations to Communicorp to operate mostly under brand licences from Global, more detail about how this would affect Real XS was confirmed. Whilst Capital Scotland would be among the stations taken over by Communicorp, Real XS in Paisley would be retained by Global, alongside 105.2 Smooth Radio and Real Radio Scotland, with Real relaunched as Heart (with all Real stations) and Real XS taking the Xfm affiliation. This would result in XS retaining local programming at key times, but during networked hours taking these shows from Xfm London, as Xfm Manchester already did, rather than taking programmes from Real XS in Manchester, which was sold to Communicorp and continues as an independent classic rock station.

It was confirmed in March 2014 that the relaunch would take place on 7 April. At other times, the station simulcast Xfm London output.

The station was based at Baillieston to the east of Glasgow and broadcast as XFM to Renfrewshire, Ayrshire, West Central Scotland and Central Scotland until the end of 2015.

XFM Scotland ceased transmission on 96.3 FM at around 6:20pm on Sunday 13 September 2015, after Global Radio decided to hand the licence back to Ofcom, ahead of XFM's relaunch as Radio X. The licence was readvertised for Glasgow and The West of Scotland, with Rockscot Ltd. being the successful applicant. Online test transmissions commenced on Monday 2 October 2017. On 13 March 2018, Rock Radio Ltd was sold to Nation Broadcasting, leading to the departure of the Rockscot management.

It was later confirmed that the station would launch as 'Nation Radio Scotland' in the autumn of 2018. The station will share branding with Nation's regional station in South Wales but is not permitted to share any programming. Test transmissions for 96.3FM began on 30 August, with an official launch on Monday 3 September.

References

External links

Radio X (United Kingdom)
Radio stations in Glasgow
2007 establishments in Scotland
Adult contemporary radio stations in the United Kingdom
Nation Broadcasting

Nation Radio Scotland


Bulldozers are crawling machines which have blades. These machines are used for pushing large amounts of dirt or rubble during demolition or construction. They have claw-like devices in the rear to loosen materials which are densely compacted.

Bulldozers are structurally different from excavators, but in many respects their functions are similar. If we talk about universal types of construction equipment, then bulldozers are used when a large amount of work is expected. According to the method of movement, the bulldozers are divided into wheeled and tracked. This construction equipment is used for levelling the soil layer, digging trenches, as well as for transporting bulk cargo. The bulldozer is an economical and efficient construction assistant.

References

Machines

Bulldozer


The Borodin Quartet is a string quartet that was founded in 1945 in what was then the Soviet Union. The four players have not always been the same people: there have been some changes to the group, but it is one of the world's longest lasting string quartets. In 2005 they celebrated their 60th anniversary. Until he retired in 2007 the cellist Valentin Berlinsky had almost always been the cellist of the quartet.

When they started they were known as the Moscow Philharmonic Quartet. In 1955 the quartet changed its name to Borodin Quartet, named after the composer Alexander Borodin who composed two famous string quartets.

They often got invitations to play in the West, but the Soviet communist government would not allow them to travel out of their country. The quartet had to accept the concerts that their government allowed them to do. They played at the funerals of the dictator Stalin and the composer Sergei Prokofiev which were on the same day (both men died on 5 March 1953. However, they were not paid anything for either event.

The quartet knew the composer Dmitri Shostakovich very well. They performed his quartets, and Shostakovich often listened to them practising and discussed with them the way he wanted them to be played. The quartet often played piano quintets with the pianist Sviatoslav Richter.

When they started in 1945 their cellist was Mstislav Rostropovich. Rudolf Barshai was their viola player. Very soon afterwards Rostropovich found he had too many other engagements, so he got Valentin Berlinsky to be their cellist. The four men who then formed the quartet signed an oath in their own blood that they would be faithful and stay together as a group. They stayed together for 20 years. Then Rostislav Dubinsky, the first violinist, defected to the West and the second violinist, Jaroslav Alexandrov, retired because of bad health. With two new players, the quartet spend two years practising together before they performed again in public.

When Communism collapsed and the Soviet Union broke up, the quartet still continued to be very famous. They travelled abroad a lot, performing in places such as London.

They have made many recordings including all Shostakovich's string quartets and all Beethoven quartets.

Other websites
 The Borodin Quartet Official Website

String quartets

Borodin Quartet


Yomi (黄泉), the Japanese word for the underworld in which horrible creatures guard the exits. According to Shinto mythology as related in Kojiki, this is where the dead go to exist and rot forever. When one eats at the hearth of Yomi it is impossible to return to the land of the living.

Overview
Yomi is similar to Hades or Hell. In the Shintoist tradition, Yomi is known because Izanami retreated to that place after her death. Izanagi followed her there and when he returned, he washed himself, creating Amaterasu, Susanoo, and Tsukuyomi. (See Japanese mythology.)

Yomi is different from Christian Hell in that all souls go there, no matter their actions in life; and one does not receive punishment for evils made when alive. It is a dirty and polluted place. In Japanese tradition, pollution is usually associated to evil. By the tradition of Kojiki, Yomi is usually believed to be underground, and its entrance to be located in Izumo province.

Yomi is ruled over by Izanami no Mikoto, the Grand Deity of Yomi (Yomotsu-Ōkami 黄泉大神).  According to Kojiki. The entrance to Yomi was blocked by Izanagi when he returned to Earth, using a great boulder (Chibiki-no-Iwa 千引の岩) at the base of the slope that leads to Yomi (Yomotsu Hirasaka 黄泉平坂).

Japanese mythology
Shinto
Afterlife

Yomi


The Toyota Fortuner is a medium-sized SUV based on the Toyota Hilux. Oreeginally assembled ae in Thailand, but later an aa in Indonesie an ither kintras, the Fortuner is biggit on the well-establisht platform o the Toyota Hilux pickup truck. It features three rows o seats an is available in rear-wheel drive or fower-wheel drive amang ithers.  The Fortuner is pairt o Toyota's IMV project in Thailand, which an aa includes the Toyota Hilux an the Innova (in Indonesie). The caur wis designed in Thailand bi Thai an Japanese ingineers.

A nummer o ingine options is available dependin on the kintra o sale, includin a 2.7 liter 2TR-FE an 4.0 liter 1GR-FE V6 petrol wi Variable Valve Timing an 2.5 2KD-FTV an 3.0 1KD-FTV common rail variable geometry turbochairger Diesel models.

Trim levels are G an G Luxury for rear-wheel drive diesel an petrol, an V for fower-wheel drive Diesel an petrol. The common rail turbo intercooled diesel haes functional scoop on its huid.

In 2007 Toyota Thailand dropped the fower-wheel drive petrol model an replaced it wi a twa-wheel drive petrol version.

This caur wis the best sellin in its category (SUV/PPV) in the Philippines an currently Thailand.

The Fortuner is no offered in Japan, Europe an North Americae, whaur the Hilux Surf is for the Japanese mercat an 4Runner in North Americae represent Toyota in the medium sized pick-up based SUV mercat.

Fortuner
Sport utility vehicles

Toyota Fortuner


In mathematics, the theta divisor Θ is the divisor in the sense of algebraic geometry defined on an abelian variety A over the complex numbers (and principally polarized) by the zero locus of the associated Riemann theta-function. It is therefore an algebraic subvariety of A of dimension dim A − 1.

Classical theory

Classical results of Bernhard Riemann describe Θ in another way, in the case that A is the Jacobian variety J of an algebraic curve (compact Riemann surface) C. There is, for a choice of base point P on C, a standard mapping of C to J, by means of the interpretation of J as the linear equivalence classes of divisors on C of degree 0. That is, Q on C maps to the class of Q − P. Then since J is an algebraic group, C may be added to itself k times on J, giving rise to subvarieties Wk.

If g is the genus of C, Riemann proved that Θ is a translate on J of Wg − 1. He also described which points on Wg − 1 are non-singular: they correspond to the effective divisors D of degree g − 1 with no associated meromorphic functions other than constants. In more classical language, these D do not move in a linear system of divisors on C, in the sense that they do not dominate the polar divisor of a non constant function.

Riemann further proved the Riemann singularity theorem, identifying the multiplicity of a point p = class(D) on Wg − 1 as the number of linearly independent meromorphic functions with pole divisor dominated by D, or equivalently as h0(O(D)), the number of linearly independent global sections of the holomorphic line bundle associated to D as Cartier divisor on C.

Later work

The Riemann singularity theorem was extended by George Kempf in 1973, building on work of David Mumford and Andreotti - Mayer, to a description of the singularities of points p = class(D) on  Wk for 1 ≤ k ≤ g − 1. In particular he computed their multiplicities also in terms of the number of independent meromorphic functions associated to D (Riemann-Kempf singularity theorem).

More precisely, Kempf mapped J locally near p to a family of matrices coming from an exact sequence which computes h0(O(D)), in such a way that Wk corresponds to the locus of matrices of less than maximal rank.  The multiplicity then agrees with that of the point on the corresponding rank locus.  Explicitly, if

h0(O(D)) = r + 1,

the multiplicity of Wk at class(D) is the binomial coefficient

When k = g − 1, this is r + 1, Riemann's formula.

Notes

References

Theta functions
Algebraic curves
Bernhard Riemann

Theta divisor


Adventist Health Studies (AHS) is a series of long-term medical research projects of Loma Linda University with the intent to measure the link between lifestyle, diet, disease and mortality of Seventh-day Adventists.

Seventh-day Adventists have a lower risk than other Americans of certain diseases, and many researchers hypothesize that this is due to dietary and other lifestyle habits.
This provides a special opportunity to answer scientific questions about how diet and other health habits affect the risk of suffering from many chronic diseases.<ref
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Two studies on Adventist health involving 24,000 and 34,000 Californian Adventists were conducted over the last 40 years.
Although not sponsored by the Adventist church itself, the church is supportive of the studies.
These studies have been the subject of significant national media coverage on programs such as ABC News: World News Tonight, Good Morning America and in the National Geographic feature article "Longevity: The Secrets of a Long Life".<ref
name="natgeo"></ref>

There is a third larger ongoing study that includes Adventists throughout the United States and Canada.

Studies

Adventist Mortality Study
The first major study of Adventists began in 1960, and has become known as the Adventist Mortality Study. Consisting of 22,940 California Adventists, it entailed an intensive 5-year follow-up and a more informal 25-year follow-up.

<blockquote>"...[The] Adventist Mortality Study (1960–1965) did indicate that Adventist men lived 6.2 years longer than non-Adventist men in the concurrent American Cancer Society Study and Adventist women had a 3.7-year advantage over their counterparts. These statistics were based on life table analyses."<ref
name="AMS"></ref></blockquote>
Specifically, comparing death rates of Adventist compared to other Californians:
Death rates from all cancers was 40% lower for Adventist men and 24% lower for Adventist women
Lung cancer 79% lower
Colorectal cancer 38% lower
Breast cancer 15% lower
Coronary heart disease 34% lower for Adventist men, 2% lower for Adventist women

Adventist Health Study 1 (AHS-1)
An additional study (1974–1988) involved approximately 34,000 Californian Adventists over 25 years of age. Unlike the mortality study, the purpose was to find out which components of the Adventist lifestyle give protection against disease.

The data from the study have been studied for more than a decade and the findings are numerous – linking diet to cancer and coronary heart disease.

Specifically:
On average Adventist men live 7.3 years longer and Adventist women live 4.4 years longer than other Californians.
Five simple health behaviors promoted by the Seventh-day Adventist Church for more than 100 years (not smoking, eating a plant-based diet, eating nuts several times per week, regular exercise, and maintaining normal body weight) increase life span up to 10 years.
Reducing consumption of red and white meat was associated with a decrease of colon cancer.
Eating legumes was protective against colon cancer.
Eating nuts several times a week reduces the risk of heart attack by up to 50%.
Eating whole meal bread instead of white bread reduced non-fatal heart attack risk by 45%.
Drinking 5 or more glasses of water a day may reduce heart disease by 50%.
Men who had a high consumption of tomatoes reduced their risk of prostate cancer by 40%.
Drinking soy milk more than once daily may reduce prostate cancer by 70%.

Adventist Health Air Pollution Study (ASHMOG)
This is a sub-study of AHS-1. It began in 1976 and is still being conducted. It includes 6,328 Adventists from California.
The study was funded by the Environmental Protection Agency.

The study linked the effects of various indoor and outdoor pollutants with respiratory diseases and lung cancer.

Adventist Health Study 2 (AHS-2)
The current study which began in 2002 with a goal of 125,000 Adventists continues to explore the links between lifestyle, diet and disease among the broader base of Seventh-day Adventists in America and Canada. As of May 2006 it had an enrollment of 96,741.

Dr. Gary Fraser with a team of researchers from the School of Public Health at Loma Linda University is conducting the study which is funded by the National Cancer Institute.
In July 2011, National Institutes of Health awarded AHS-2 a $5.5 million 5-year grant to continue the study.

While the study is on-going, some findings have been reported:
"The 5-unit BMI difference between vegans and nonvegetarians indicates a substantial potential of vegetarianism to protect against obesity. Increased conformity to vegetarian diets protected against risk of type 2 diabetes after lifestyle characteristics and BMI were taken into account. Pesco- and semi-vegetarian diets afforded intermediate protection."
"A vegetarian dietary pattern is associated with a more favorable profile of MRFs and a lower risk of MetS."
"Men with higher intake of dairy foods, but not nondairy calcium, had a higher risk of prostate cancer compared with men having lower intakes. Associations were nonlinear, suggesting greatest increases in risk at relatively low doses."

Adventist Religion & Health Study (AHRS)
This sub-study of AHS-2 began in 2006 and is funded by the National Institute on Aging.
It is also known as the Biopsychosocial Religion and Health Study (BRHS).

The study has exceeded its goal of 10,000 participants with 11,835 subjects as of 2008.

See also
 Adventist Health International

References

External links
 Loma Linda University Adventist Health Studies
 "Adventist Health Studies: Past, Present and Future" by Gary E. Fraser. Adventist Review June 25, 2009

Determinants of health
American medical research
Seventh-day Adventist Church
Loma Linda University
Cohort studies

Adventist Health Studies


Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand and silt can be carried in suspension in river water and on reaching the sea bed deposited by sedimentation; if buried, they may eventually become sandstone and siltstone (sedimentary rocks) through lithification.

Sediments are most often transported by water (fluvial processes), but also wind (aeolian processes) and glaciers. Beach sands and river channel deposits are examples of fluvial transport and deposition, though sediment also often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of aeolian transport and deposition. Glacial moraine deposits and till are ice-transported sediments.

Classification

Sediment can be classified based on its grain size, grain shape, and composition.

Grain size

Sediment size is measured on a log base 2 scale, called the "Phi" scale, which classifies particles by size from "colloid" to "boulder".

Shape

The shape of particles can be defined in terms of three parameters. The form is the overall shape of the particle, with common descriptions being spherical, platy, or rodlike. The roundness is a measure of how sharp grain corners are. This varies from well-rounded grains with smooth corners and edges to poorly rounded grains with sharp corners and edges. Finally, surface texture describes small-scale features such as scratches, pits, or ridges on the surface of the grain.

Form

Form (also called sphericity) is determined by measuring the size of the particle on its major axes. William C. Krumbein proposed formulas for converting these numbers to a single measure of form, such as

where , , and  are the long, intermediate, and short axis lengths of the particle. The form  varies from 1 for a perfectly spherical particle to very small values for a platelike or rodlike particle.

An alternate measure was proposed by Sneed and Folk:

which, again, varies from 0 to 1 with increasing sphericity.

Roundness

Roundness describes how sharp the edges and corners of particle are. Complex mathematical formulas have been devised for its precise measurement, but these are difficult to apply, and most geologists estimate roundness from comparison charts. Common descriptive terms range from very angular to angular to subangular to subrounded to rounded to very rounded, with increasing degree of roundness.

Surface texture
Surface texture describes the small-scale features of a grain, such as pits, fractures, ridges, and scratches. These are most commonly evaluated on quartz grains, because these retain their surface markings for long periods of time. Surface texture varies from polished to frosted, and can reveal the history of transport of the grain; for example, frosted grains are particularly characteristic of aeolian sediments, transported by wind. Evaluation of these features often requires the use of a scanning electron microscope.

Composition
Composition of sediment can be measured in terms of:
 Parent rock lithology
 Mineral composition
 Chemical make-up

This leads to an ambiguity in which clay can be used as both a size-range and a composition (see clay minerals).

Sediment transport

Sediment is transported based on the strength of the flow that carries it and its own size, volume, density, and shape. Stronger flows will increase the lift and drag on the particle, causing it to rise, while larger or denser particles will be more likely to fall through the flow.

Fluvial processes: rivers, streams, and overland flow

Particle motion
Rivers and streams carry sediment in their flows. This sediment can be in a variety of locations within the flow, depending on the balance between the upwards velocity on the particle (drag and lift forces), and the settling velocity of the particle. These relationships are shown in the following table for the Rouse number, which is a ratio of sediment settling velocity (fall velocity) to upwards velocity.

where
  is the settling velocity
  is the von Kármán constant
  is the shear velocity

If the upwards velocity is approximately equal to the settling velocity, sediment will be transported downstream entirely as suspended load. If the upwards velocity is much less than the settling velocity, but still high enough for the sediment to move (see Initiation of motion), it will move along the bed as bed load by rolling, sliding, and saltating (jumping up into the flow, being transported a short distance then settling again). If the upwards velocity is higher than the settling velocity, the sediment will be transported high in the flow as wash load.

As there are generally a range of different particle sizes in the flow, it is common for material of different sizes to move through all areas of the flow for given stream conditions.

Fluvial bedforms

Sediment motion can create self-organized structures such as ripples, dunes, or antidunes on the river or stream bed. These bedforms are often preserved in sedimentary rocks and can be used to estimate the direction and magnitude of the flow that deposited the sediment.

Surface runoff

Overland flow can erode soil particles and transport them downslope. The erosion associated with overland flow may occur through different methods depending on meteorological and flow conditions.
 If the initial impact of rain droplets dislodges soil, the phenomenon is called rainsplash erosion.
 If overland flow is directly responsible for sediment entrainment but does not form gullies, it is called "sheet erosion".
 If the flow and the substrate permit channelization, gullies may form; this is termed "gully erosion".

Key fluvial depositional environments

The major fluvial (river and stream) environments for deposition of sediments include:
 Deltas (arguably an intermediate environment between fluvial and marine)
 Point bars
 Alluvial fans
 Braided rivers
 Oxbow lakes
 Levees
 Waterfalls

Aeolian processes: wind

Wind results in the transportation of fine sediment and the formation of sand dune fields and soils from airborne dust.

Glacial processes

Glaciers carry a wide range of sediment sizes, and deposit it in moraines.

Mass balance

The overall balance between sediment in transport and sediment being deposited on the bed is given by the Exner equation. This expression states that the rate of increase in bed elevation due to deposition is proportional to the amount of sediment that falls out of the flow. This equation is important in that changes in the power of the flow change the ability of the flow to carry sediment, and this is reflected in the patterns of erosion and deposition observed throughout a stream. This can be localized, and simply due to small obstacles; examples are scour holes behind boulders, where flow accelerates, and deposition on the inside of meander bends. Erosion and deposition can also be regional; erosion can occur due to dam removal and base level fall. Deposition can occur due to dam emplacement that causes the river to pool and deposit its entire load, or due to base level rise.

Shores and shallow seas

Seas, oceans, and lakes accumulate sediment over time. The sediment can consist of terrigenous material, which originates on land, but may be deposited in either terrestrial, marine, or lacustrine (lake) environments, or of sediments (often biological) originating in the body of water. Terrigenous material is often supplied by nearby rivers and streams or reworked marine sediment (e.g. sand). In the mid-ocean, the exoskeletons of dead organisms are primarily responsible for sediment accumulation.

Deposited sediments are the source of sedimentary rocks, which can contain fossils of the inhabitants of the body of water that were, upon death, covered by accumulating sediment. Lake bed sediments that have not solidified into rock can be used to determine past climatic conditions.

Key marine depositional environments

The major areas for deposition of sediments in the marine environment include:
 Littoral sands (e.g. beach sands, runoff river sands, coastal bars and spits, largely clastic with little faunal content)
 The continental shelf (silty clays, increasing marine faunal content).
 The shelf margin (low terrigenous supply, mostly calcareous faunal skeletons)
 The shelf slope (much more fine-grained silts and clays)
 Beds of estuaries with the resultant deposits called "bay mud".

One other depositional environment which is a mixture of fluvial and marine is the turbidite system, which is a major source of sediment to the deep sedimentary and abyssal basins as well as the deep oceanic trenches.

Any depression in a marine environment where sediments accumulate over time is known as a sediment trap.

The null point theory explains how sediment deposition undergoes a hydrodynamic sorting process within the marine environment leading to a seaward fining of sediment grain size.

Environmental issues

Erosion and agricultural sediment delivery to rivers
One cause of high sediment loads is slash and burn and shifting cultivation of tropical forests. When the ground surface is stripped of vegetation and then seared of all living organisms, the upper soils are vulnerable to both wind and water erosion. In a number of regions of the earth, entire sectors of a country have become erodible. For example, on the Madagascar high central plateau, which constitutes approximately ten percent of that country's land area, most of the land area is devegetated, and gullies have eroded into the underlying soil to form distinctive gulleys called lavakas. These are typically  wide,  long and  deep. Some areas have as many as 150 lavakas/square kilometer, and lavakas may account for 84% of all sediments carried off by rivers. This siltation results in discoloration of rivers to a dark red brown color and leads to fish kills.

Erosion is also an issue in areas of modern farming, where the removal of native vegetation for the cultivation and harvesting of a single type of crop has left the soil unsupported. Many of these regions are near rivers and drainages. Loss of soil due to erosion removes useful farmland, adds to sediment loads, and can help transport anthropogenic fertilizers into the river system, which leads to eutrophication.

The Sediment Delivery Ratio (SDR) is fraction of gross erosion (interill, rill, gully and stream erosion) that is expected to be delivered to the outlet of the river. The sediment transfer and deposition can be modelled with sediment distribution models such as WaTEM/SEDEM. In Europe, according to WaTEM/SEDEM model estimates the Sediment Delivery Ratio is about 15%.

Coastal development and sedimentation near coral reefs

Watershed development near coral reefs is a primary cause of sediment-related coral stress. The stripping of natural vegetation in the watershed for development exposes soil to increased wind and rainfall, and as a result, can cause exposed sediment to become more susceptible to erosion and delivery to the marine environment during rainfall events. Sediment can negatively affect corals in many ways, such as by physically smothering them, abrading their surfaces, causing corals to expend energy during sediment removal, and causing algal blooms that can ultimately lead to less space on the seafloor where juvenile corals (polyps) can settle.

When sediments are introduced into the coastal regions of the ocean, the proportion of land, marine and organic-derived sediment that characterizes the seafloor near sources of sediment output is altered. In addition, because the source of sediment (i.e. land, ocean, or organically) is often correlated with how coarse or fine sediment grain sizes that characterize an area are on average, grain size distribution of sediment will shift according to relative input of land (typically fine), marine (typically coarse), and organically-derived (variable with age) sediment.  These alterations in marine sediment characterize the amount of sediment that is suspended in the water column at any given time and sediment-related coral stress.

Biological considerations
In July 2020, marine biologists reported that aerobic microorganisms (mainly), in "quasi-suspended animation", were found in organically-poor sediments, up to 101.5 million years old, 250 feet below the seafloor in the South Pacific Gyre (SPG) ("the deadest spot in the ocean"), and could be the longest-living life forms ever found.

See also

References

Further reading

Sedimentology
Environmental soil science
Petrology

Sediment


Theodor Otto Helm (9 April 1843 – 25 December 1920) was an Austrian music critic and writer.

Theodor Otto Helm was a leading figure in Viennese musical life and a prominent music critic in Vienna for fifty years (1866–1916). While Helm specialized in criticism of the works of Ludwig van Beethoven, Anton Bruckner, Johannes Brahms, Richard Wagner, Franz Liszt, and Antonín Dvořák, he also wrote on younger composers including Béla Bartók, Gustav Mahler, and Arnold Schoenberg. Heavily involved in the Vienna music scene, including the Wiener Akademischer Wagner Verein, Helm counted both Bruckner and Brahms as close acquaintances.

Biography

In 1853 Helm began his studies at the Benedictine Schottengymnasium in Vienna. He eventually focused his efforts on studying law. Helm received his PhD in 1870. He taught as an instructor of the history of music and aesthetics at the conservatory of  since beginning in 1874. In 1900 he was named professor.

Helm began his writing career in Vienna's Neues Fremdenblatt in 1867. He continued his essays and music criticisms in , a Leipzig weekly, (1870–1905) and continued with the paper when subsumed by the Neue Zeitschrift für Musik.

Helm's greatest work is arguably his 1885 Beethovens Streichquartette: Versuch einer technischen Analyse dieser Werke im Zusammenhange mit ihren geistigen Gehalt (Leipzig, 1885). This analysis of Beethoven's string quartets is considered seminal work and has been reprinted many times by publishers across the world.

He contributed freelance writings to Pester Lloyd (a German newspaper issued in Budapest) and the Viennese Salonblatt and the  (1884–1901)

While initially critical of Bruckner's work, in 1883 Helm converted in his views and became one of Bruckner's strongest advocates, penning dozens of glowing reviews throughout the rest of Bruckner's life. Bruckner and Helm regularly corresponded between 1883 until Bruckner's death in 1896. Often Bruckner was seeking a favorable review from Helm in Deutsche Zeitung, albeit second hand account, of a non-Vienna venue concert. On occasion Bruckner visited Helm at his home at III Rochusgasse 10 in Vienna to visit and go over his symphonic scores with Helm. Bruckner showed appreciation for Helm's appreciation of his work by sending him a case of his favorite wine along with a letter of gratitude.

In 1902 Helm founded a three-year Bruckner Celebration (Akademische Gesangverein), six years after the composer's death. However the well known annual Bruckner festival was not founded until 1929.

Ever the Viennese loyalist, Helm preferred Hans Richter and the lush string section of the Vienna Philharmonic over the "Prussian precision" of the Berlin Philharmonic.

Helm attended the funerals ceremonies of Anton Bruckner (1896), Johannes Brahms (1897), and probably Johann Strauss II (1899), and Hugo Wolf (1903) all in Vienna.

Helm not only appreciated fine composition and performances but also excellent acoustics. After the opening concert in the Golden Hall of the Musikverein (Grosse Musikvereinssaal), Helm commented on the impressive acoustics: "This achievement, is partly a stroke of pure luck (unfortunately acoustics still cannot be precisely forecast or calculated), and on the other hand it is undeniably merited by the excellent architect Hansen..."

Aesthetic objectivity

While many view Helm in the conservative German nationalist camp, he was simultaneously regarded as one of the "most fair-minded and balanced Viennese critics" in Vienna. As Helm approached middle age, the Deutsche Zeitung was still a liberal paper. However, in 1884 as the paper took a decidedly anti-Semitic turn, Helm was hired as the chief music critic for Deutsche Zeitung and attempted to maintain his critical objectivity in his writings against the politics of the editors. Over the subsequent decades, Deutsche Zeitung touted itself as a highly anti-semitic German nationalist newspaper.

Some criticized Helm for writing to pander to the political views of his audience and thus for writing contradictory reviews of a given performance. He was attacked in the press for being a "helmet without a head". Hugo Wolf retaliated to a critical review by calling Helm "an idiot".

Other argued that Helm sought to not let the political bias of the management taint his writings. Helm's political comments seem "to be added almost reluctantly, even gratuitously, as if he were bowing to the wish of management". His criticism of Brahms included comments deriding his liberal supporters more often than Brahms' works which Helm generally held in high regard.

As further evidence of Helm's rejection of German nationalistic bias, Helm collaborated with both the Jewish critic Hirshfeld and Slavic critic Lvovsky

Personal life

Theodor Otto Helm was born on 9 April 1843, in Vienna. His parents Dr. Julius Helm (1813–1844) and Julie Freiin von Forstern had married a year earlier, in 1842. Theodor was their only child. Julius Helm died when Theodor was only one year old. Theodor's mother died when he was 15, leaving Theodor in the care of Julius's uncle, general-auditor Friedrich Drahtschmidt v. Märentheim (1801-1885), who was friends of Robert and Clara Schumann.

While in school, Helm became friends with a classmate Richard Müller whose father was Dr. Karl Müller (1813–1868), director of the Erzherzogliche Gallerie, later renamed the Albertina museum, and a prominent music critic from nobility. The elder Müller was largely responsible for introducing young Theodor to Vienna's musical events and salons. Upon Karl Müller's death, Helm replaced Müller as music critic for the Neues Fremdenblatt.

Helm married Irene Dorothea Müller (1844–1911), Karl Müller's daughter on 1 June 1869.

In 1870 Theodor and Irene Helm had their first child Julius. Tragically, Irene completely lost her hearing in 1870. It is not clear if this was a complication related to childbirth. As a very young boy Julius studied violin under Johannes Brahms, who suspected that Julius was a musical genius. Sadly, Julius died at the early age of five years and nine months.

In 1872 Theodor and Irene had a daughter Gabriela Mathilde Helm. An accomplished pianist, she lived until 1945.

In 1875 Theodor and Irene Helm had a second son Theodor Ludwig Moritz Helm (1875–1963). Theodor Jr. attempted to emulate his father by publishing several critical essays on Anton Bruckner's music, but failing to follow his father's success while under the economic pressures of providing for his growing family, he later settled to work as a civil servant with the Postal Service.

Theodor Otto Helm died of old age on 25 December 1920. He was buried on 27 December 1920 in the Zentralfriedhof in Vienna, near the graves of his fellow critic Eduard Hanslick and the composers Beethoven, Brahms, Schubert, Goldmark, Wolf, Salieri and several members of the Strauss family.

Writings (selective list)
 Beethovens letzte Quartette, Tonhalle, 1868
 Beethovens Streichquartette: Versuch einer technischen Analyse dieser Werke im Zusammenhange mit ihren geistigen Gehalt (Leipzig, 1885, 3/1921/R)
 50 Jahre Wiener Musikleben, 1916 (autobiographie)

References

Sources

Further reading

Crawford Howie, Anton Bruckner: A Documentary Biography (vol 1 and 2), Lewiston, New York: Edwin Mellen Press, 2002
Krebs, Michael: Theodor Helm (1843–1920). Ein Musikschriftsteller im Umkreis von Anton Bruckner. – Diss. University Vienna 2000. ("Ursprünglich Beamter in Wien, dann Kritiker bei verschiedenen Tages- und Wochen-Zeitungen")
Mahler and his world, edited by Karen Painter, Princeton, New Jersey: Princeton University Press, 2002.

Walker, Frank, Hugo Wolf; a biography, New York: Knopf, 1952

External links

1843 births
1920 deaths
Austrian music critics
Austrian musicologists
Writers from Vienna
Burials at the Vienna Central Cemetery
19th-century musicologists

Theodor Helm


San Pancrazio  Airfield is an abandoned Second World War military airfield in Italy, located approximately 4 km northeast of San Pancrazio Salentino in the province of Brindisi in Apulia, on the south-east Italy coast.  Built in 1943 by United States Army Engineers,  the airfield was primarily a Fifteenth Air Force B-24 Liberator heavy bomber base used in the strategic bombing of Germany.   San Pancrazio  was also used by tactical aircraft of Twelfth Air Force in the Italian Campaign.

Known units assigned to the airfield were:
 82d Fighter Group, 3–10 October 1943, P-38 Lightning, (12AF)
 340th Bombardment Group, 16 October-19 November 1943, B-25 Mitchell, (12AF)
 376th Bombardment Group, 17 November 1943 – 19 April 1945, B-24 Liberator, (15AF)
 451st Bombardment Group, 5 March-6 April 1944, B-24 Liberator, (15AF)

San Pancrazio  Airfield is probably the best-preserved American heavy bomber base in Italy.   Most of the main runway and taxiways remain, along with numerous dispersal pads.  Numerous remains of wartime buildings are also visible.   After the war, the airfield may have been used as San Pancrazio Airport, but today several agricultural buildings are on the main runway.  The grass areas of the airfield are used as agricultural fields, but most of the concreted areas remain.

References

 Maurer, Maurer. Air Force Combat Units of World War II. Maxwell AFB, Alabama: Office of Air Force History, 1983. .

External links

Airfields of the United States Army Air Forces in Italy
Airports established in 1943

San Pancrazio Airfield


Samgyetang is Korean ginseng chicken soup. It's a food commonly eaten during the summer, especially on the three days called 'bok day's.

Samgyetang is made of a whole young chicken stuffed with sticky rice, ginseng, jujube, garlic, and ginger. The chicken is "closed" shut and cooked in a soup. The richness of the broth depends on the style of the cook, as is the added  ingredients that may be added. Some Samgyetang broths are cooked for hours. This broth is added to the chicken cooking separately to create a very rich soup. Other broths are lighter and clear.

Samgyetang is usually served with salt and pepper, which is put in a small separate dish to dip the meat. Some people like to add the seasoning directly into the soup. It is usually served with kkakdugi (radish kimchi) and some restaurants will offer regular kimchi as well.

Korean food
Soups

Samgyetang


The Punic Wars were a series of conflicts fought between Rome and Carthage between 264 and 146 BC. They were probably the largest wars in the ancient world. The term "Punic" comes from the Latin word Punicus (or Poenicus). This was the word the Romans used for the Carthaginians, due to their Phoenician ancestry.

The main cause of the Punic Wars was the clash of interests between the existing empire of Carthage and the expanding Roman Republic. What was at stake was control of the trading around the Mediterranean sea. Carthage lost the three wars.

 First Punic War 264 to 241 BC. Hannibal's father Hamilcar Barca was the Carthaginian general. Mainly fought on the sea and in Sicily. Rome came out on top as a dominant naval power, and Sicily was ceded to Rome.
 Second Punic War 218 to 201 BC. Hannibal was the Carthaginian general. Hannibal crossed the Alps with war elephants in order to attack Rome on land, because they had put their fortifications on the coast, expecting a naval attack. Carthage lost when Romans invaded Africa. This war cemented Rome as the most powerful state in the Western Mediterranean.
 Third Punic War 149 to 146 BC. Carthage lost again and their city was completely destroyed by the Romans.

Context
Carthage was a trading nation founded by Phoenicians. It was the dominant sea power in the western Mediterranean. It was a maritime empire, in contrast to the land-based Roman empire. The Romans decided they needed Sicily, which was then in Carthaginian hands. The consequence was a series of wars which lasted over a hundred years, and ended in the utter destruction of Carthage.

References

Other websites
 Punic Wars Timeline

Punic Wars


Gastric bypass surgery is a surgery in which the stomach is divided and the gastrointestinal tract is redirected. The surgery is performed on people who have morbid obesity or have type 2 diabetes, high blood pressure or other weight-related health problems.

As with all surgery, problems may occur. Some people could die after having the surgery.

Gastric bypass surgery can be done using methods that make only small incisions (cuts) into the abdomen. It is one of the most difficult surgeries to perform that way. Advantages of using those methods include that patients don't have to stay in the hospital as long, they have less pain, it doesn't take as long to recover, and the scars are smaller.

References

Surgery
Obesity

Gastric bypass surgery


SportsCenter is the daily sports news program of ESPN. It is widely spread out in the whole world, with famous citations in movies and international editions, as the SportsCenter Brasil (the Brazilian edition), the SportsCenter Asia and the Sportscentre (Canada). The SportsCenter Brasil has recently completed 3000 editions.

English-language television programs

SportsCenter


Dynamic random access memory is the most commonly used form of RAM.

DRAM is called dynamic (or active), because it must be refreshed all the time or it will lose the data which it is supposed to be storing. Because it loses data when power is removed, DRAM is called volatile. This word comes from the Latin adjective volātilis, which means "flying, fleeting, transitory".

Refreshing DRAM means reading the data from the DRAM and directly writing them back to the DRAM.
DRAM is made up of millions of very small capacitors. Each of these capacitors has a transistor to let energy in and out. The capacitor slowly loses energy, and if the DRAM is not refreshed, in the end one or more of the capacitors will let so much energy out, that for example a 1 will become a 0, so data will be lost or corrupted. Almost all computers refresh their DRAM many times per second.

Comparison DRAM and SRAM
DRAM is often compared to SRAM (Static RAM). SRAM is able to store data as long as power/energy is used. There is no need to refresh it. SRAM can also be faster than DRAM. But SRAM is much more expensive than DRAM. Also, SRAM uses more electric power and heats up much faster than DRAM.
DRAM and SRAM lose the data when the power to them is turned off, unlike non-volatile random-access memory.

Computer hardware
Computer memory

Dynamic random-access memory


Allen Francis Doyle is a fictional character created by Joss Whedon for the television series Angel. The character was portrayed by Glenn Quinn.  Doyle is a seer who receives prophetic visions from The Powers That Be, usually of people in peril. Half-human, half-demon, his demon heritage allows him to manage them without suffering any permanent damage. His half-Brachen demon physiology grants him the ability to shift from normal human to demonic appearance, in which he has heightened sense of smell and superior strength, speed, stamina, and dexterity, the last of which allows him to twist his head around in such a manner as to fake a broken neck. However, Doyle rarely used his Brachen powers, preferring to remain human, thus limiting his usefulness in a fight.

Character history
Doyle is an Irishman who was born to a human mother and a Brachen demon father. Doyle never knew his father or anyone on that side of his family, and his own demonic genes didn't physically manifest themselves until he was 21 years old. At that time, Doyle was a third grade teacher and a soup kitchen volunteer married to a woman named Harriet. He didn't take the news of his demonic heritage very well. In spite of Harriet's acceptance of his other side, his marriage ultimately disintegrated. Doyle hid behind the flimsy veneer of a ne'er-do-well hustler and con artist, seemingly more interested in where his next drink was coming from than helping others.

Later, he was approached by a fellow Brachen demon, Lucas, who told Doyle that the Scourge, a militant group of pure blood demons, was after all half-breeds and begged for Doyle's help.  Doyle turned Lucas away, believing this wasn't his problem. Soon after he received a vision, which he described as "splittin' migraines that come with pictures". The vision showed him a group of massacred Brachen demons. Doyle searched the city to find out if what he had seen was real – it was. These visions, which come from The Powers That Be, are what led Doyle to Angel. As Doyle says, "We all got something to atone for," and therefore the two join forces to fight evil in Los Angeles. Once Cordelia Chase joins the team, Angel Investigations is officially formed.

Doyle soon falls in love with Cordelia, but is afraid she will reject him upon finding out about his demonic heritage, especially when she makes it clear on multiple occasions that she considers many demons evil. He also forms a close, brotherly bond with Angel as the result of their shared Irish heritage and similar demonic backgrounds, although his combat skills were limited due to his dislike of his demon half, which meant that he rarely transformed despite the greater strength he possessed in that form. Despite Doyle's reluctance to discuss his past, Angel and Cordelia learn about him when Harriet returns to his life, wanting a divorce so she can marry an Ano-Movic demon named Richard Howard Straley, though she ultimately calls off the engagement after learning that obtaining the blessing of the Straley clan would require Richard to kill Doyle by eating his brain.

Doyle's past again comes back to haunt him when the Scourge returns, threatening the Listers, another tribe of human/demon hybrids. During the battle, Doyle sacrifices his own life to save his friends, the Listers, and the entire city of Los Angeles from the Beacon, a device which could destroy any being "tainted" with human blood. While trying to successfully deactivate the Beacon, the radiation from the weapon killed Doyle by literally vaporizing his entire body into dust and ash. In doing so, Doyle fulfills the Listers' prophecy of the "Promised One," the bringer purported to save them from the Scourge in the last days of the 20th century. Before Doyle dies, he shares a passionate kiss with Cordelia (who had only recently learned of – and accepted – Doyle's demonic heritage). Unbeknownst to her, he was also passing his visions on to her.

After Doyle's death, he briefly appears in the third-season episode "Birthday" and the fifth-season episode "You're Welcome," the former in a flashback and the latter courtesy of the Angel Investigations commercial he and Cordelia had made before he died, which Cordelia watches as she reflects on the team's history. In "Birthday", it is revealed that, in the alternate timeline that Cordelia has been sent to, Doyle passed his visions on to Angel before his death, and their power, along with the absence of Cordelia's humanizing influence, drove him insane.

In the fifth season of Angel, Lindsey McDonald briefly assumes Doyle's identity in an ultimately failed attempt to convince Angel and the others, that Spike, not Angel, is the subject of the Shanshu Prophecy. Angel and Cordelia both display great anger at this abuse of Doyle's name and legacy.

Writing and acting
Originally, it was Whistler, an ambiguous demon played by Max Perlich and first seen in the Buffy episode "Becoming, Part One," who was to be a supporting character in the spin-off series starring Angel, but instead, the character of Doyle was created with similar character traits. Quinn was asked if he knew Doyle was Irish before he auditioned, he responded "I went and I read it in American and Joss Whedon said 'Hey, let's do it in Irish and see where it takes us.'.. The Irish thing just really clicked."

Whedon considered killing off Doyle early on from the opening episodes, "That was always a plan, and clearly that character didn't mesh. He was a very popular character, but the mesh was very difficult in ways that made it hard to write. Glenn had a kind of intensity that was kind of like David [Boreanaz's], and David already has that. It could have gone a different way, but that was the plan we had and we decided to execute it. Glenn Quinn knew that it was an issue and he learned pretty early on. I said this is what we're going to do...' and I promised him a hero's exit." At the TCA Writers Guild of America West party in 2000, supervising producer David Fury stated, "Joss has bandied about, 'I love the idea of putting a character in the main credits as one of the stars of the show and then kill him right off the bat.' But in the case of Doyle, he didn't want to kill off Doyle. It just became a situation. The work situation became difficult... It's hard enough to make a television show without the headaches."

In an interview in Dreamwatch #118, David Fury discussed plans for Doyle to return to the show, perhaps in the role of a "big bad." However, Quinn died in December 2002 before anything could come of the talks.

Appearances

Canonical appearances
In Angel, Doyle was a series regular for part of the show's first season (1999). He appeared in nine episodes overall. After the events of "Parting Gifts", he disappeared from the opening credits.

Archived footage of the character appears in the episodes, "Birthday" and "You're Welcome".

Non-canonical appearances

Comics
In July 2006, IDW Comics released Doyle: Spotlight. It features Doyle shortly before his first encounter with Angel.

Doyle is also a main character in the following comics (ordered by chronology):
 Surrogates, Earthly Possessions, Angel #4, Hunting Ground

Novels
Doyle is a main character in the following novels (ordered by chronology):
 Not Forgotten, Close to the Ground, Soul Trade, Redemption, Shakedown, Hollywood Noir, Avatar, Bruja, and The Summoned

The Buffy/Angel crossover book, Monster Island, set in the third season of Angel also includes a story linked to Doyle and his father, who is a pure-blood supremacist who wanted to purge Doyle of his human half. Having learned of his son's death, Doyle's father – a full Brachen demon called Axtius, possessing sufficient strength to even go head-to-head with Angel in a fight – sends several demons to attack Harry, sending her to the hospital, and subsequently attempts to kill Angel, blaming him for his son's 'foolish attempt to save a pack of pitiful half-breeds'. In their final confrontation, Angel defeats Axtius when unarmed despite Axtius wielding a powerful mystical weapon, taunting the Brachen by saying that he would have been ashamed of Doyle's very human act of sacrifice and redemption, Axtius subsequently being incinerated by his former second-in-command for his failure.

Notes and references

Angel (1999 TV series) characters
Buffyverse demons
Fictional private investigators
Fictional Irish people
Fictional schoolteachers
Fictional con artists
Fictional characters with precognition
Fictional characters with superhuman strength
Fictional half-demons
Fictional characters from the 20th century
Television characters introduced in 1999
Fictional immigrants to the United States
Fictional demon hunters
Male characters in television
Fictional occult and psychic detectives

Allen Francis Doyle


The carbon cycle is the way carbon is stored and replaced on Earth. Some of the main events take hundreds of millions of years, others happen annually.

The main ways that carbon gets into the carbon cycle are volcanoes, and the burning of fossil fuels like coal and gas. Through most of history, volcanoes were the biggest source of carbon to the carbon cycle, but in the last hundred years, people burning fossil fuels have been adding about a hundred times more CO2 to the air than volcanoes. That is, for every ton of CO2 added to the air by volcanoes, about 100 tons of CO2 have been added to the air by people through combustion.

The main way carbon gets taken out of the atmosphere is by photosynthesis by living organisms.  Some of this gets released as they die and decompose, but a proportion gets buried in sediment.  This is shown in the diagram. Sediment turns to rock, and it is the carbonate rocks like limestone which contain the now-solid CO2.  Some of the carbon from plants also becomes part of the soil, where it can stay for a long time before decomposing.

Another process takes CO2 out of the air. Weathering by rain washes out CO2 in the form of dilute carbonic acid. This reacts with rock, helping to dissolve and destroy it. This also ends up as sediment.
"Weathering is a large consumer of the atmospheric carbon dioxide essential for dissolving rocks".

Some CO2 is also dissolved in the ocean.  Right now, the oceans are taking in more CO2 than they are releasing, every year.  However, this is making the oceans more acidic.

The store of carbon in sedimentary rock is far greater than the CO2 in the atmosphere (this is not shown in the diagram). Eventually it returns to the air as oceanic plates subduct in plate tectonics. At the margins of plate boundaries (and some other places) volcanoes form and spew out CO2. This completes the cycle.

Summary
The carbon cycle is a process where carbon is recycled through the ecosystem. The concentration of carbon in living matter (18%) is almost 100 times greater than its concentration in the earth (0.19%). So living things extract carbon from their nonliving environment. For life to continue, this carbon must be recycled. See the diagram for a detailed look at the carbon cycle. An example of a route carbon takes in this cycle is carbon dioxide in the atmosphere is absorbed by plants and used in photosynthesis to produce sugars which the plant uses for energy. When the plant dies, it decomposes and the carbon stored in the plant will, over millions of years, form into coal (a fossil fuel). The coal is burnt and gives off carbon dioxide which goes into the atmosphere.

At the moment, the carbon cycle, and how human activity is affecting it, is a big topic in international news. Fossil fuels are a non-renewable resource which means that they cannot be replaced easily. Our use of fossil fuels has nearly doubled every 20 years since 1900.  This release of carbon dioxide contributes to the greenhouse effect and acid rain.

The carbon cycle was discovered by Joseph Priestley and Antoine Lavoisier, and popularized by Humphry Davy.

Related pages
 Orbiting Carbon Observatory
 water cycle
 nitrogen cycle

References

Geochemistry
Ecology
Carbon

Carbon cycle


Mathias Sandorf is an 1885 adventure book by French writer Jules Verne. It was first serialized in Le Temps in 1885, and it was Verne's epic Mediterranean adventure. It employs many of the devices that had served well in his earlier novels: islands, cryptograms, surprise revelations of identity, technically advanced hardware and a solitary figure bent on revenge. Verne dedicated the novel to the memory of Alexandre Dumas, hoping to make Mathias Sandorf the Monte Cristo of Voyages extraordinaires (The Extraordinary Voyages) series.

Overview
In Trieste, 1867, two petty criminals, Sarcany and Zirone, intercept a carrier pigeon. They find a ciphered message attached to its leg and uncover a plot to liberate Hungary from Habsburg-Austrian rule. The two meet with Silas Toronthal, a corrupt banker and form a plan to deliver the conspirators to the police in exchange for a rich reward. The three Hungarian conspirators, Count Mathias Sandorf, Stephen Bathory and Ladislas Zathmar (in their Hungarian form: Sándor Mátyás, Báthory István and Szatmári László, respectively) are arrested and sentenced to death. They plot an escape, but are recaptured and killed one by one.

Fifteen years later, the renowned physician Dr. Antekirtt (actually Sandorf who survived by faking his death) sets out to avenge his friends. Enlisting the aid of two French acrobats, Pescade and Matifou, he scours the Mediterranean in search of those who planned the betrayal. Rich beyond all imagination, wielding great power and master of an island fortress filled with advanced weaponry, Dr. Antekirtt will not rest until justice is done.

The Wanderer's Tale: An Adventure Subgenre
In the generation after Dumas, Jules Verne wrote a number of Wanderer adventures. Three of the most notable, Michael Strogoff, The Steam House (La Maison à vapeur) and Mathias Sandorf, are set in three of Europe's great Empires: the Russian, the British (in India), and the Austrian. Their plots and themes have a good deal in common, as Jean Yves Tadie points out. Each one is about the empire's political troubles, each features a pursuer who is himself pursued, each has a trio of characters at its centre and each grants minor importance (compared with other Verne books) to machinery.

(From Seven Types of Adventure: An Eniology of Major Genre by Martin Green Penn State Press).

Background on the novel
The fictional plot of Verne's book begins on May 18, 1867 - by which date preparations for the rising in Hungary are said to be almost complete. It is a matter of actual historical record - easily available to Verne in his research for the book - that on May 29, 1867, the Diet of Hungary ratified the Austro-Hungarian Compromise of 1867, under which the Hungarians gained a very considerable autonomy but shelved their demand for complete independence from Austria.

Though the compromise is not explicitly mentioned in the book, it is clear that the aim of Sandorf and his fellow conspirators is to avert this ratification, seize control of Buda (Pest, Buda and Óbuda were unified in 1873) and other major Hungarian cities, and get the Diet to declare instead a complete Hungarian independence - gambling that Austria, enfeebled by its recent defeat in the Austro-Prussian War, would have no choice but to accept this fait accompli. (If successful, such a move would have substantially changed later European history, up to the outbreak of World War I.)

The conduct of the Austrian authorities, once the conspiracy is discovered, can also be seen against the same background: The Austrians move in complete secrecy to arrest, court-martial and swiftly execute the radical Hungarians, while cementing the deal with their more amenable compatriots in the glare of publicity.

Verne's readers in 1885 could know, even before reading of the police arresting Sandorf and his friends, that the conspiracy would fail, that the moderate Hungarians' compromise with Austria would go ahead and that in fact Hungarians would prove fairly content with it.

Verne claimed that Sandorf was modeled on his publisher. Like Hetzel, a former exile, Sandorf has fervent patriotism and a high moral sense. Dr Antekirtt is a mixture of Hetzel and Bixio, one of the publisher's friends. Others see similarities with Hungarian freedom fighter Lajos Kossuth (who, like Sandorf, remained unreconciled to the compromise) and Austrian prince Ludwig Salvator.

The action moves from Trieste down the Adriatic coast, to Sicily and the shores of North Africa. "I wish my readers to learn everything they should know about the Mediterranean," Verne wrote Hetzel, "which is why the action transports them to twenty different places" (Simon Vierne, Jules Verne, Paris Ballard 1986). Several of the settings come from Verne's own travels, a rescue during a storm off Malta and visits to Catania and Etna.

Verne researched the Italian landscape by rereading some of Stendhal's works notably Promenades in Rome and The Charterhouse of Parma. Verne may have first heard about the foiba beneath the Pisino Castle in Charles Yriarte's works Les Bords de l'Adriatique (The Ports of the Adriatic) - (Hachette, Paris 1878) and Trieste e l'Istria (Trieste and Istria) - (Hachette, Paris 1875). Yriatre described the old castle as well as his trip down into the gorge. He also mentioned an experiment by a young nobleman, Count Esdorff, to find the end of the underground river. Unfortunately the count's boat never made it out of the cave.

The first edition was dedicated to Alexandre Dumas. His son was so moved by the love expressed in the dedication that he wrote a letter to Verne which said "I've been loving you for so long that I feel like your brother", and admitted that in literature Verne is Dumas' son more than he himself.

The steam yacht of doctor Antekirtt, Savarena, is a true portrait of Verne's own steam yacht which he bought from the eccentric millionaire marquis de Préaulx for 60,000 F.

Film, TV or theatrical adaptations

Mathias Sandorf was performed as a five-act play in Paris in the 1880s. It even played the Boston theatre in the fall of 1888 as well as at Niblo's Garden in New York in October 1888.

As a two-act musical (in Hungarian with subtitles), it was performed in 2022-2023

There have also been three screen adaptations of Mathias Sandorf. The first Mathias Sandorf was made in 1921 and directed by Henri Fescourt. It starred Yvette Andréyor, Romuald Joubé, Jean Toulout. During the 1920s Fescourt was one of the most successful directors working for Cineroman, and Mathias Sandorf, Les Gransa and Mandarin were among his most popular works.

In 1963 Georges Lampin directed another version Mathias Sandorf starring Louis Jourdan, Francisco Rabal, Renaud Mary and Serena Vergano.

The most recent screen version was a television miniseries made for French television in 1979. Directed by Jean-Pierre Decourt it starred Hungarian actor István Bujtor as Mathias Sandorf, Ivan Desny as Zathmar, and also Amadeus August, Claude Giraud, Monika Peitsch, Sissy Höfferer and Jacques Breuer.

References

External links

Read Chapter 1 of the classic edition reissued by ROH Press
Click to read the first two chapters of Ed Brumgach's new 2005 English translation.
Click to read the original French version.
Mathias Sandorf international list of first editions.
Mathias Sandorf Article and little known facts.

1885 French novels
Novels by Jules Verne
Novels set in Hungary
Novels set in Croatia
French novels adapted into films
French novels adapted into television shows
Fiction set in 1867
Novels set in the 1860s

Mathias Sandorf


The Transvaal (lit. beyond the Vaal [pale river]) is the name of an area of northern South Africa. At the start, it made up a great part of the independent Boer South African Republic. Before the Anglo-Boer War of 1899-1902 it became the Transvaal Colony. It is one of the original provinces of the Union of South Africa from 1910 until 1994 with capital in Pretoria. The province no longer exists, and its territory now forms the provinces of Gauteng, Limpopo and Mpumalanga and part of the North West Province. Even though it no longer exists as an administrative unit, the Transvaal is still a commonly used geographical term and retains its historical meaning.

Geography of South Africa

Transvaal


Nucleic acid secondary structure is the basepairing interactions within a single nucleic acid polymer or between two polymers. It can be represented as a list of bases which are paired in a nucleic acid molecule.
The secondary structures of biological DNAs and RNAs tend to be different: biological DNA mostly exists as fully base paired double helices, while biological RNA is single stranded and often forms complex and intricate base-pairing interactions due to its increased ability to form hydrogen bonds stemming from the extra hydroxyl group in the ribose sugar.

In a non-biological context, secondary structure is a vital consideration in the nucleic acid design of nucleic acid structures for DNA nanotechnology and DNA computing, since the pattern of basepairing ultimately determines the overall structure of the molecules.

Fundamental concepts

Base pairing

In molecular biology, two nucleotides on opposite complementary DNA or RNA strands that are connected via hydrogen bonds are called a base pair (often abbreviated bp). In the canonical Watson-Crick base pairing, adenine (A) forms a base pair with thymine (T) and guanine (G) forms one with cytosine (C) in DNA. In RNA, thymine is replaced by uracil (U). Alternate hydrogen bonding patterns, such as the wobble base pair and Hoogsteen base pair, also occur—particularly in RNA—giving rise to complex and functional tertiary structures.  Importantly, pairing is the mechanism by which codons on messenger RNA molecules are recognized by anticodons on transfer RNA during protein translation. Some DNA- or RNA-binding enzymes can recognize specific base pairing patterns that identify particular regulatory regions of genes.
Hydrogen bonding is the chemical mechanism that underlies the base-pairing rules described above. Appropriate geometrical correspondence of hydrogen bond donors and acceptors allows only the "right" pairs to form stably. DNA with high GC-content is more stable than DNA with low GC-content, but contrary to popular belief, the hydrogen bonds do not stabilize the DNA significantly and stabilization is mainly due to stacking interactions.

The larger nucleobases, adenine and guanine, are members of a class of doubly ringed chemical structures called purines; the smaller nucleobases, cytosine and thymine (and uracil), are members of a class of singly ringed chemical structures called pyrimidines. Purines are only complementary with pyrimidines: pyrimidine-pyrimidine pairings are energetically unfavorable because the molecules are too far apart for hydrogen bonding to be established; purine-purine pairings are energetically unfavorable because the molecules are too close, leading to overlap repulsion. The only other possible pairings are GT and AC; these pairings are mismatches because the pattern of hydrogen donors and acceptors do not correspond. The GU wobble base pair, with two hydrogen bonds, does occur fairly often in RNA.

Nucleic acid hybridization

Hybridization is the process of complementary base pairs binding to form a double helix.  Melting is the process by which the interactions between the strands of the double helix are broken, separating the two nucleic acid strands. These bonds are weak, easily separated by gentle heating, enzymes, or physical force. Melting occurs preferentially at certain points in the nucleic acid. T and A rich sequences are more easily melted than C and G rich regions. Particular base steps are also susceptible to DNA melting, particularly T A and T G base steps. These mechanical features are reflected by the use of sequences such as TATAA at the start of many genes to assist RNA polymerase in melting the DNA for transcription.

Strand separation by gentle heating, as used in PCR, is simple providing the molecules have fewer than about 10,000 base pairs (10 kilobase pairs, or 10 kbp). The intertwining of the DNA strands makes long segments difficult to separate. The cell avoids this problem by allowing its DNA-melting enzymes (helicases) to work concurrently with topoisomerases, which can chemically cleave the phosphate backbone of one of the strands so that it can swivel around the other. Helicases unwind the strands to facilitate the advance of sequence-reading enzymes such as DNA polymerase.

Secondary structure motifs

Nucleic acid secondary structure is generally divided into helices (contiguous base pairs), and various kinds of loops (unpaired nucleotides surrounded by helices). Frequently these elements, or combinations of them, are further classified into additional categories including, for example, tetraloops, pseudoknots, and stem-loops. Topological approaches can be used to categorize and compare complex structures that arise from combining these elements in various arrangements.

Double helix

The double helix is an important tertiary structure in nucleic acid molecules which is intimately connected with the molecule's secondary structure. A double helix is formed by regions of many consecutive base pairs.

The nucleic acid double helix is a spiral polymer, usually right-handed, containing two nucleotide strands which base pair together.  A single turn of the helix constitutes about ten nucleotides, and contains a major groove and minor groove, the major groove being wider than the minor groove. Given the difference in widths of the major groove and minor groove, many proteins which bind to DNA do so through the wider major groove.   Many double-helical forms are possible; for DNA the three biologically relevant forms are A-DNA, B-DNA, and Z-DNA, while RNA double helices have structures similar to the A form of DNA.

Stem-loop structures

The secondary structure of nucleic acid molecules can often be uniquely decomposed into stems and loops. The stem-loop structure (also often referred to as an "hairpin"), in which a base-paired helix ends in a short unpaired loop, is extremely common and is a building block for larger structural motifs such as cloverleaf structures, which are four-helix junctions such as those found in transfer RNA. Internal loops (a short series of unpaired bases in a longer paired helix) and bulges (regions in which one strand of a helix has "extra" inserted bases with no counterparts in the opposite strand) are also frequent.

There are many secondary structure elements of functional importance to biological RNAs; some famous examples are the Rho-independent terminator stem-loops and the tRNA cloverleaf. Active research is on-going to determine the secondary structure of RNA molecules, with approaches including both experimental and computational methods (see also the List of RNA structure prediction software).

Pseudoknots

A pseudoknot is a nucleic acid secondary structure containing at least two stem-loop structures in which half of one stem is intercalated between the two halves of another stem.  Pseudoknots fold into knot-shaped three-dimensional conformations but are not true topological knots.  The base pairing in pseudoknots is not well nested; that is, base pairs occur that "overlap" one another in sequence position. This makes the presence of general pseudoknots in nucleic acid sequences impossible to predict by the standard method of dynamic programming, which uses a recursive scoring system to identify paired stems and consequently cannot detect non-nested base pairs with common algorithms. However, limited subclasses of pseudoknots can be predicted using modified dynamic programs.
Newer structure prediction techniques such as stochastic context-free grammars are also unable to consider pseudoknots.

Pseudoknots can form a variety of structures with catalytic activity and several important biological processes rely on RNA molecules that form pseudoknots. For example, the RNA component of the human telomerase contains a pseudoknot that is critical for its activity. The hepatitis delta virus ribozyme is a well known example of a catalytic RNA with a pseudoknot in its active site. Though DNA can also form pseudoknots, they are generally not present in standard physiological conditions.

Secondary structure prediction

Most methods for nucleic acid secondary structure prediction rely on a nearest neighbor thermodynamic model. A common method to determine the most probable structures given a sequence of nucleotides makes use of a dynamic programming algorithm that seeks to find structures with low free energy. Dynamic programming algorithms often forbid pseudoknots, or other cases in which base pairs are not fully nested, as considering these structures becomes computationally very expensive for even small nucleic acid molecules. Other methods, such as stochastic context-free grammars can also be used to predict nucleic acid secondary structure.

For many RNA molecules, the secondary structure is highly important to the correct function of the RNA — often more so than the actual sequence. This fact aids in the analysis of non-coding RNA sometimes termed "RNA genes". One application of bioinformatics uses predicted RNA secondary structures in searching a genome for noncoding but functional forms of RNA. For example, microRNAs have canonical long stem-loop structures interrupted by small internal loops.

RNA secondary structure applies in RNA splicing in certain species. In humans and other tetrapods, it has been shown that without the U2AF2 protein, the splicing process is inhibited. However, in zebrafish and other teleosts the RNA splicing process can still occur on certain genes in the absence of U2AF2. This may be because 10% of genes in zebrafish have alternating TG and AC base pairs at the 3' splice site (3'ss) and 5' splice site (5'ss) respectively on each intron, which alters the secondary structure of the RNA. This suggests that secondary structure of RNA can influence splicing, potentially without the use of proteins like U2AF2 that have been thought to be required for splicing to occur.

Secondary structure determination
RNA secondary structure can be determined from atomic coordinates (tertiary structure) obtained by X-ray crystallography, often deposited in the Protein Data Bank. Current methods include 3DNA/DSSR and MC-annotate.

See also

DNA nanotechnology
Molecular models of DNA
DiProDB. The database is designed to collect and analyse thermodynamic, structural and other dinucleotide properties.
RNA CoSSMos

References

External links
MDDNA: Structural Bioinformatics of DNA
Abalone — Commercial software for DNA modeling
DNAlive: a web interface to compute DNA physical properties. Also allows cross-linking of the results with the UCSC Genome browser and DNA dynamics.

DNA
Biophysics
Molecular structure
RNA

Nucleic acid secondary structure


Adams Morgan is a culturally diverse neighborhood in Northwest Washington, D.C.. It is centered at the intersection of 18th Street and Columbia Road. Adams Morgan is the center of Washington's Hispanic immigrant community. It is a major night life area with many bars and restaurants, particularly along 18th Street (the primary commercial district) and Columbia Road. Much of the neighborhood has 19th- and early 20th-century row houses and apartment buildings.

Adjacent to Adams Morgan is Dupont Circle to the south, Kalorama-Sheridan to the southwest, Mount Pleasant to the north, and Columbia Heights to the east.  The neighborhood is bounded by Connecticut Avenue to the southwest, Rock Creek Park to the west, Harvard Street to the north, 16th Street to the east, and Florida Avenue to the south.

History
The name Adams Morgan was originally hyphenated. It is derived from the names of two, formerly segregated area elementary schools—the older, all-black Thomas P. Morgan Elementary School (now defunct) and the all-white John Quincy Adams Elementary School.  Pursuant to the 1954 Bolling v. Sharpe Supreme Court ruling, District schools were desegregated in 1955.  The Adams-Morgan Community Council, comprising both Adams and Morgan schools and the neighborhoods they served, was formed in 1958.  The city drew boundaries of the neighborhood through three preexisting neighborhoods – Washington Heights, Lanier Heights, and Meridian Hill – naming the resulting area after both schools.

In the late 1960s, a group of residents organized and worked with city officials to plan and construct a new elementary school and recreational complex that was conceived as a community hub, a concept that 40 years later has become a favored one in public school facilities design.  The development was named the Marie H. Reed Learning Center after Bishop Reed, a community activist, minister and leader.  It featured a daycare center, tennis and basketball courts, a solar-heated swimming pool, health clinic, athletic field and outdoor chess tables.

Cultural diversity

Adams Morgan, together with the nearby Mount Pleasant and Columbia Heights, serve as a gateway community for immigrants. Since the 1960s, the predominant international presence in both communities has been Latino, with the majority of immigrants coming from El Salvador, Guatemala and other Central American countries.  Since the early 1970s, like other areas of the nation, Adams Morgan had seen a growing influx of immigrants from Africa, Asia and the Caribbean, as well. Gentrification and the resulting high cost of housing, however, have displaced many immigrants and long-time African American residents, particularly those with young children. Many small businesses have also been displaced. The community still retains a degree of diversity, most evident in its array of international shops and restaurants.  Restaurants in Adams Morgan offer ethnic cuisines, among them Spanish, Ethiopian, Guatemalan, Mexican, Italian, Dutch, Vietnamese, Ghanaian, Cajun, Brazilian, Palestinian, Peruvian, Pakistani cuisine, Thai, Lebanese, Somali, and Chinese.

Adams Morgan also has become a thriving spot for night life, with a number of bars and clubs featuring live music. Over 90 establishments possess liquor licenses, putting it on level with other popular nightlife areas like Georgetown and Dupont Circle. Local stores along the 18th Street corridor were rapidly replaced with late-night establishments, leading to a moratorium on new liquor licenses by the Alcohol Beverage Control Board in 2000 after successful lobbying by resident groups. The moratorium was renewed in 2004, but eased to allow new restaurant licenses.

Although many immigrants and African-American residents have left Adams Morgan, the long-time institutions that meet the needs of Latinos and other non English-speaking residents ontinue to serve immigrants and their families.  Adams Morgan is home to Mary's Center, a clinic focusing on healthcare delivery to Spanish-speaking patients, and the Latino Economic Development Corporation, as well as numerous businesses and churches that employ and cater to immigrants. Adjacent Mt. Pleasant also hosts a number of commercial enterprises, social service agencies and other institutions that help to anchor local immigrants to the area.

Adams Morgan continues to show linguistic and cultural diversity of its public schools. Many of the families served live beyond the boundaries established for routine student enrollment; however, Adams, Reed, and H.D. Cooke elementary schools all have international populations, with children from well over 30 nations in attendance.  Latino and African-American children comprise the majority of students in the public schools, and virtually all are children of color.

The second Sunday of September, the neighborhood hosts the Adams Morgan Day Festival, a multicultural street celebration with live music and food and crafts booths.  And, weather permitting, every Saturday—except during the coldest winter months—local growers sell fresh, organically grown produce and herbs; baked and canned goods; cheeses; cold-pressed apple juice and fresh flowers at the farmers market, in operation in the same location for more than 30 years.  Also on summer Saturdays, the Western Art Market is open at the Marie Reed School.

In the 1960s, the neighborhood's attractions included the Avignon Freres bakery and restaurant, the Café Don restaurant, the Ontario motion picture theater, and the Showboat Lounge jazz nightclub.  In the 1980s, Hazel's featured live blues and jazz.  Its soul food offerings made it a favorite of black jazz musicians like Dizzy Gillespie when they came to town.

Transportation
The area is not directly served by the Metrorail system. The nearest station, Woodley Park-Zoo/Adams Morgan (Red Line) is in the Woodley Park neighborhood, but was renamed in 1999 to reflect the station's proximity to Adams Morgan. The nearest station on the Green Line is Columbia Heights. In March 2009, the Washington Metropolitan Area Transit Authority (WMATA) began operating a DC Circulator bus route connecting the center of Adams Morgan with both Metro stations. The area is also served by a number of WMATA Metrobus lines.

Politics
Adams Morgan is in the service area of Advisory Neighborhood Commission 1C.  The boundaries of ANC 1C are 16th Street NW on the east, Harvard Street NW and Rock Creek Park on the north, Rock Creek Park and Connecticut Avenue on the west, and Florida Avenue and U Street on the south.

References

Other websites

 Advisory Neighborhood Commission 1C
 Adams Morgan at Cultural Tourism DC
 Adams Morgan Neighborhood Crime Fighters

Neighborhoods in Washington, D.C.

Adams Morgan