Symbiogenesis, or endosymbiotic theory, is an evolutionary theory of the origin of eukaryotic cells from prokaryotic organisms, first articulated in 1905 and 1910 by the Russian botanist Konstantin Mereschkowski, advanced and substantiated with microbiological evidence by Lynn Margulis in 1967. It holds that the organelles distinguishing eukaryote cells evolved through symbiosis of individual single-celled prokaryotes; the theory holds that mitochondria, plastids such as chloroplasts, other organelles of eukaryotic cells are descended from free-living prokaryotes taken one inside the other in endosymbiosis. Mitochondria appear to be phylogenetically related to Rickettsiales proteobacteria, chloroplasts to nitrogen-fixing filamentous cyanobacteria. Among the many lines of evidence supporting symbiogenesis are that new mitochondria and plastids are formed only through binary fission, that cells cannot create new ones otherwise; the Russian botanist Konstantin Mereschkowski first outlined the theory of symbiogenesis in his 1905 work, The nature and origins of chromatophores in the plant kingdom, elaborated it in his 1910 The Theory of Two Plasms as the Basis of Symbiogenesis, a New Study of the Origins of Organisms.
Mereschkowski knew of the work of botanist Andreas Schimper, who had observed in 1883 that the division of chloroplasts in green plants resembled that of free-living cyanobacteria, who had himself tentatively proposed that green plants had arisen from a symbiotic union of two organisms. In 1918 the French scientist Paul Jules Portier published Les Symbiotes, in which he claimed that the mitochondria originated from a symbiosis process. Ivan Wallin advocated the idea of an endosymbiotic origin of mitochondria in the 1920s; the Russian botanist Boris Kozo-Polyansky became the first to explain the theory in terms of Darwinian evolution. In his 1924 book A New Principle of Biology. Essay on the Theory of Symbiogenesis, he wrote, "The theory of symbiogenesis is a theory of selection relying on the phenomenon of symbiosis." These theories did not gain traction until more detailed electron-microscopic comparisons between cyanobacteria and chloroplasts, combined with the discovery that plastids and mitochondria contain their own DNA led to a resurrection of the idea of symbiogenesis in the 1960s.
Lynn Margulis advanced and substantiated the theory with microbiological evidence in a 1967 paper, On the origin of mitosing cells. In her 1981 work Symbiosis in Cell Evolution she argued that eukaryotic cells originated as communities of interacting entities, including endosymbiotic spirochaetes that developed into eukaryotic flagella and cilia; this last idea has not received much acceptance, because flagella lack DNA and do not show ultrastructural similarities to bacteria or to archaea. According to Margulis and Dorion Sagan, "Life did not take over the globe by combat, but by networking". Christian de Duve proposed that the peroxisomes may have been the first endosymbionts, allowing cells to withstand growing amounts of free molecular oxygen in the Earth's atmosphere. However, it now appears that peroxisomes may be formed de novo, contradicting the idea that they have a symbiotic origin; the fundamental theory of symbiogenesis as the origin of mitochondria and chloroplasts is now accepted.
According to Keeling and Archibald, the usual way to distinguish organelles from endosymbionts is by their reduced genome sizes. As an endosymbiont evolves into an organelle, most of their genes are transferred to the host cell genome; the host cell and organelle need to develop a transport mechanism that enables the return of the protein products needed by the organelle but now manufactured by the cell. Cyanobacteria and α-proteobacteria are the most related free-living organisms to plastids and mitochondria respectively. Both cyanobacteria and α-proteobacteria maintain a large genome encoding thousands of proteins. Plastids and mitochondria exhibit a dramatic reduction in genome size when compared with their bacterial relatives. Chloroplast genomes in photosynthetic organisms are 120-200kb encoding 20-200 proteins and mitochondrial genomes in humans are 16kb and encode 37 genes, 13 of which are proteins. Using the example of the freshwater amoeboid, Paulinella chromatophora, which contains chromatophores found to be evolved from cyanobacteria and Archibald argue that this is not the only possible criterion.
Nowack and her colleagues performed gene sequencing on the chromatophore and found that only 867 proteins were encoded by these photosynthetic cells. Comparisons with their closest free living cyanobacteria of the genus Synechococcus revealed that chromatophores underwent a drastic genome shrinkage. Chromatophores contained genes that were accountable for photosynthesis but were deficient in genes that could carry out other biosynthetic functions.
Tracy Clayton is an American writer best known as the co-host of the critically acclaimed BuzzFeed podcast Another Round, on hiatus since 2017. Her work has been recognized by Fast Company and The Root, who described her as "a superstar at BuzzFeed, the millennial-driven media powerhouse where she writes big, funny things." Clayton was laid off from BuzzFeed in September 2018 amid company-wide downsizing. She hosts the Netflix podcast Strong Black Legends, for which she interviews iconic Black Americans in the entertainment industry. Clayton is from Louisville and received her bachelor's degree from Transylvania University in Lexington. Before joining BuzzFeed full-time in 2014, Clayton wrote for Madame Noire, Uptown Magazine, The Urban Daily, PostBourgie and The Root, she developed the popular Tumblr, "Little Known Black History Facts", now a feature on Another Round. She was named the Ida B. Wells Media Expert-in-Residence at Wake Forest University's Anna Julia Cooper Center from 2016–2017. Clayton and her co-worker Heben Nigatu launched the first episode of Another Round, produced by BuzzFeed, on March 25, 2015.
The show received positive critical acclaim. The A. V. Club described Clayton and Nigatu as "passionate and sharp in their distinct points of view." It was named to "Best of 2015" lists by iTunes, Slate and The Atlantic. An Okayplayer profile said, "known all over the digital world as one of the sharpest voices in the podcast game as well as Black Twitter, Tracy Clayton is one of the smartest people in whatever room she occupies." Elle praised Clayton and co-host Heben Nigatu's ability to "serve up a blend of humor and frank observation that not the most deft hosts can seem to replicate." Clayton made headlines in the fall when she pressed then-Presidential candidate Hillary Clinton to address the crime bill her husband passed as president:'o you look at the state of black America and think,'wow, we fucked this up for black people?' " The Guardian praised their work as "witty, intelligent." Writing for The Guardian, critic Sasha Frere-Jones called Clayton and Nigatu "leading American cultural critics."Clayton announced that she had been laid off by BuzzFeed on September 19, 2018, along with most of the other staffers who had worked on BuzzFeed's original podcasts.
On February 11, 2019, Netflix's Strong Black Lead initiative announced that they were launching a new podcast featuring interviews with legendary Black members of Hollywood, called Strong Black Legends, to be hosted by Clayton. The first podcast premiered on February 12, 2019 and Lynn Whitfield was the guest. Fast Company, "Most Creative People" The Root, The Root 100 Ebony, Power 100, "Disruptor" Clayton lives in Brooklyn. "Tracy Clayton Is Speaking Things Into Existence". Death, Sex & Money. 11 January 2017. Retrieved 9 March 2017. Official Twitter
Concealed shoes hidden in the fabric of a building have been discovered in many European countries, as well as in other parts of the world, since at least the early modern period. Independent researcher Brian Hoggard has observed that the locations in which these shoes are found – in chimneys, under floors, above ceilings, around doors and windows, in the roof – suggest that some may have been concealed as magical charms to protect the occupants of the building against evil influences such as demons and witches. Others may have been intended to bestow fertility on a female member of the household, or been an offering to a household deity. Concealed shoes have been found in many types of building, including country houses, public houses, a Benedictine monastery and a Baptist church; the earliest yet reported was discovered behind the choirstalls in Winchester Cathedral, which were installed in 1308. Northampton Museum maintains a Concealed Shoe Index, which by 2012 contained 1900 reports of discoveries from Britain and half from the 19th century.
The overwhelming majority have been worn, many have been repaired. Most finds are of about half of them belonging to children; the custom appears to have died out some time during the 20th century. Since at least the early modern period it was a common custom to hide objects such as written charms, dried cats, horse skulls, witch bottles in the structure of a building, but concealed shoes are by far the most common items discovered. Archaeologist Brian Hoggard has observed that the locations in which these shoes are found suggest that at least some were concealed as magical charms to protect the occupants of the building against evil influences; such hidden caches of objects are known by archaeologists as spiritual middens. Northampton Museum maintains a Concealed Shoe Index, which by 1998 contained more than 1100 reports of concealed shoes from Britain but some from as far away as Canada. By 2012 it had increased to 1900 entries, of which half date from the 19th century; the custom of concealing shoes in the fabric of a building appears to have more or less died out some time during the 20th century, although not entirely.
The shoe manufacturer Norvic incorporated a pair of their women's high-leg boots in the foundations of their new factory built in 1964, an more recent account comes from Knebworth House, where in 1991 an estate worker's shoe replaced an "old court shoe", discovered behind some panelling. Only 50 post-1900 instances of concealed shoes have been recorded. Concealed shoes have been discovered in several European countries, as well as in North America and Australia. Although deposits have been found throughout the United States they are concentrated in New England and the northeastern United States, the latter of, first colonised by immigrants from the East Anglia region of England. An analysis of the Concealed Shoe Index maintained by Northampton Museum, conducted by June Swann and published in 1996, reveals that the most common place of concealment is the chimney, fireplace or hearth, followed by under the floor or above the ceiling, as many concealed in the roof. Shoes have been found around doors and windows, under the stairs, among the foundations.
Concealed shoes have been discovered in many types of building: country cottages, town houses, manor houses, workhouses, public houses, two Oxford colleges, St John's and Queen's. They have been found in ecclesiastical buildings, including a Benedictine monastery in Germany and a Baptist church in Cheshire, England; the earliest concealed shoe yet reported was discovered behind the choirstalls in Winchester Cathedral, which were installed in 1308. Most of the concealed shoes found to date are made of leather, but wooden clogs and rubber galoshes have been reported, among others; the overwhelming majority have been worn, many show signs of repair. All ages are represented in the shoe sizes, from babies to adults, but there is little difference in the ratio of adult male to female shoes, at 21.5 per cent and 26.5 per cent respectively. Most finds are of single shoes, but some pairs have been discovered. About half of the shoes so far discovered belonged to children. Apart from their significance to folklore, concealed shoes give an important insight into what ordinary people have worn on their feet.
Several theories have been advanced to account for the incorporation of shoes into the fabric of a building, one of, that they served as some kind of fertility charm. There is a long-standing connection between shoes and fertility exemplified by the nursery rhyme, "There was an Old Woman Who Lived in a Shoe", the custom of casting a shoe after a bride as she leaves for her honeymoon or attaching shoes to the departing couple's car. Archaeologist Ralph Merrifield has observed that in the English county of Lancashire women who wished to conceive might try on the shoes of a woman who had just given birth, a custom known as smickling. Another theory, the one favoured by most scholars, argues that shoes were concealed to protect against evil influences such as demons, ghosts and familiars. Witches were believed to be attracted by the human scent of a shoe, after entering one found themselves trapped, as they are unable to reverse. Merrifield has suggested that an unofficial 14th-century English saint, John Schorne, may have been the source of the belief that shoes had the power to protect against evil.
Schorne was said to have succeeded in trapping the Devil in a boot, a legend that may have its origin in a more ancient folk belief, which the Church was attempting to convert into an "approved Christian rite". Archaeolo
Artavazik Church of the 7th century is located in a stone field one kilometer northeast just a little outside the village of Byurakan in the Aragatsotn Province of Armenia. The name of the church goes back to the Armenian king at the time, presumed to be the founder; the church is a small cruciform monocoque type structure with a long west arm and semicircular eastern apse, narrower by far than the other three arms. In the northeast corner adjacent to the apse is prayer room. Large portions of walls and a section of the gable roof at the western end are preserved, as well as a large section of the lower-drum of a belfry that rests above the front entry; the belfry had been added in the 13th century but has collapsed. Four tall and thin columns stood on the rim of a lower drum and once supported a narrower upper drum with a small conical dome above. A small portion of their footings may still be seen attached to the base drum; these lower and upper drums were both decorated with interwoven geometric knot designs that encircled the structural elements.
There was a large octagonal drum and dome that stood above the center of the church before the collapse of its main roof. Close to the church to the southwest are the remains of the badly damaged main dome. Behind the church and across a small ravine is a huge khachkar monument from the 13th century with a shed roof at the rear. Dum-Tragut, Armenien: 3000 Jahre Kultur zwischen West und Ost, Germany: Trescher Verlag Brady Kiesling, Rediscovering Armenia, p. 15. Kiesling, Rediscovering Armenia: Guide, Armenia: Matit Graphic Design Studio Armenian Architectural Studies Artavazik Church Pictures With Bellfry FindArmenia.com: Artavazik Church
The United States House of Representatives elections in California, 2004 was an election for California's delegation to the United States House of Representatives, which occurred as part of the general election of the House of Representatives on November 2, 2004. The districts after the 2000 census were gerrymandered to protect incumbents of both parties, so there was no change in the party balance, 33 Democrats and 20 Republicans; the following are the final results from the Secretary of State of California. California Legislative District Maps RAND California Election Returns: District Definitions 2004 General Election Returns for United States Congress California Elections Page 109th United States Congress Political party strength in California Political party strength in U. S. states United States House of Representatives elections, 2004
The Service-Oriented Localisation Architecture Solution, or SOLAS, enables the global conversation in communities and is an open source project of The Rosetta Foundation. SOLAS was conceived at The Rosetta Foundation Design Fest in San Francisco, 5–6 February 2011; the original design was further developed as an open translation and localisation space at the Localisation Research Centre at the University of Limerick in Ireland, part-financed by the Centre for Next Generation Localisation, a Centre for Science and Technology, supported by Science Foundation Ireland, the Irish Governments research funding agency, industry partners. A YouTube video was published on 18 February 2011. SOLAS was demonstrated at the AGIS event in Addis Ababa, Ethiopia, in December 2011; the SOLAS Design is based on the ORM Design Principles: O-pen, R-ight, M-inimalistic. SOLAS consists of SOLAS Productivity; the ORM Design Principles guiding the design of SOLAS were introduced by Reinhard Schäler, Director LRC at the University of Limerick, Ireland, at the LRC XVII - Social Localisation event and at TM-Europe.
SOLAS Match has been released under an open source GPL license and can be downloaded from the SOLAS web page. SOLAS has implemented open standards developed by the localisation community in OASIS and the W3C. SOLAS is made up of SOLAS Productivity. SOLAS Match is an open translation and localisation space that allow individuals with translation skills to find and download translation tasks in an intuitive and user-friendly way. SOLAS Match has been used by The Rosetta Foundation successfully in a number of pilot projects. SOLAS Productivity supports the work of individuals working on translation tasks by offering them an easy to use translation environment and access to language and linguistic resources. SOLAS Productivity consists of six components, all sharing an XLIFF-based common data layer: Workflow Recommender Localisation Knowledge Repository XLIFF Phoenix MT-Mapper LocConnect At the University of Limerick: SOLAS download