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SUMMARY / RELATED TOPICS

Fibroblast

A fibroblast is a type of biological cell that synthesizes the extracellular matrix and collagen, produces the structural framework for animal tissues, plays a critical role in wound healing. Fibroblasts are the most common cells of connective tissue in animals. Fibroblasts have a branched cytoplasm surrounding an elliptical, speckled nucleus having two or more nucleoli. Active fibroblasts can be recognized by their abundant rough endoplasmic reticulum. Inactive fibroblasts are smaller, spindle-shaped, have a reduced amount of rough endoplasmic reticulum. Although disjointed and scattered when they have to cover a large space, when crowded locally align in parallel clusters. Unlike the epithelial cells lining the body structures, fibroblasts do not form flat monolayers and are not restricted by a polarizing attachment to a basal lamina on one side, although they may contribute to basal lamina components in some situations. Fibroblasts can migrate over substratum as individual cells, again in contrast to epithelial cells.

While epithelial cells form the lining of body structures, it is fibroblasts and related connective tissues which sculpt the "bulk" of an organism. The life span of a fibroblast, as measured in chick embryos, is 57 ± 3 days. Fibroblasts and fibrocytes are two states of the same cells, the former being the activated state, the latter the less active state, concerned with maintenance and tissue metabolism. There is a tendency to call both forms fibroblasts; the suffix "-blast" is used in cellular biology to denote a stem cell or a cell in an activated state of metabolism. Fibroblasts are morphologically heterogeneous with diverse appearances depending on their location and activity. Though morphologically inconspicuous, ectopically transplanted fibroblasts can retain positional memory of the location and tissue context where they had resided, at least over a few generations; this remarkable behavior may lead to discomfort in the rare event that they stagnate there excessively. The main function of fibroblasts is to maintain the structural integrity of connective tissues by continuously secreting precursors of the extracellular matrix.

Fibroblasts secrete the precursors of all the components of the extracellular matrix the ground substance and a variety of fibers. The composition of the extracellular matrix determines the physical properties of connective tissues. Like other cells of connective tissue, fibroblasts are derived from primitive mesenchyme, thus they express the intermediate filament protein vimentin, a feature used as a marker to distinguish their mesodermal origin. However, this test is not specific as epithelial cells cultured in vitro on adherent substratum may express vimentin after some time. In certain situations epithelial cells can give rise to fibroblasts, a process called epithelial-mesenchymal transition. Conversely, fibroblasts in some situations may give rise to epithelia by undergoing a mesenchymal to epithelial transition and organizing into a condensed, laterally connected true epithelial sheet; this process is seen in many developmental situations, as well as in wound healing and tumorigenesis.

Fibroblasts make collagen fibres, glycosaminoglycans and elastic fibers, growing individuals' fibroblasts are dividing and synthesizing ground substance. Tissue damage stimulates induces the production of fibroblasts. Besides their known role as structural components, fibroblasts play a critical role in an immune response to a tissue injury, they are early players in initiating inflammation in the presence of invading microorganisms. They induce chemokine synthesis through the presentation of receptors on their surface. Immune cells respond and initiate a cascade of events to clear the invasive microorganisms. Receptors on the surface of fibroblasts allow regulation of hematopoietic cells and provide a pathway for immune cells to regulate fibroblasts. Fibroblasts, like the tumor-associated host fibroblasts, play a crucial role in immune regulation through TAF-derived extracellular matrix components and modulators. TAF are known to be significant in the inflammatory response as well as immune suppression in tumors.

TAF-derived ECM components initiate the ECM remodeling. The ECM remodeling is described as changes in the ECM as a result of enzyme activity which can lead to degradation of the ECM. Immune regulation of tumors is determined by the ECM remodeling because the ECM is responsible for regulating a variety of functions, such as proliferation and morphogenesis of vital organs. In many tumor types those related to the epithelial cells, ECM remodeling is common. Examples of TAF-derived ECM components include Tenascin and Thrombospondin-1, which can be found in sites of chronic inflammation and carcinomas respectively. Immune regulation of tumors can occur through the TAF-derived modulators. Although these modulators may sound similar to the TAF-derived ECM components, they differ in the sense that they are responsible for the variation and turnover of the ECM. Cleaved ECM molecules can play a critical role in immune regulation. Proteases like matrix metalloproteineases and the uPA system are known to cleave the ECM.

These proteases are derived from fibroblasts. Mouse embryonic fibroblasts are used as "feeder cells" in human embryonic stem cell research. However, many researchers are phasing out

2004 IAAF World Outdoor Meetings

The 2004 IAAF World Outdoor Meetings was the second edition of the annual global series of one-day track and field competitions organized by the International Association of Athletics Federations. The series had four levels: 2004 IAAF Golden League, IAAF Super Grand Prix, IAAF Grand Prix and IAAF Grand Prix II. There were 6 Golden League meetings, 8 Super Grand Prix category meetings, 9 IAAF Grand Prix category meetings and 11 Grand Prix II meetings, making a combined total of 34 meetings for the series; the series hosted the same number of meetings as the previous year. The Qatar Athletic Super Grand Prix was added to Super Grand Prix, the Helsinki Grand Prix was dropped from the Grand Prix circuit and the Cena Slovenska - Slovak Gold Grand Prix II meeting was replaced by the Grande Premio Rio de Atletismo. Three meetings changed venue from 2003: the Bislett Games moved from Oslo to Bergen due to stadium developments, the Athens Grand Prix Tsiklitiria was moved from Trikala to Heraklion, the Brother Znamensky Memorial moved from Tula, Russia to Kazan.

Performances on designated events on the circuit earned athletes points which qualified them for entry to the 2004 IAAF World Athletics Final, held on 18–19 September in Monaco

TGK PG

TGK PG is an automated cargo spacecraft project to replace Progress-MS as the Russian logistic vehicle to the ISS. It was requested for development to take advantage of the increased lift capacity of the Soyuz-2.1b. The initial development contract was awarded to RSC Energia by Roscosmos on December 11, 2015; the spacecraft is not expected to fly before 2020. Born out of the need to reduce the flights to the ISS from 2018 onward, it was designed as a radical departure from the Progress design, it would incorporate technologies developed from the Orel and Progress-MS projects. One critical characteristic would be a 370 days on-orbit design life, compared to the 210 days of the Progress and Soyuz; this would allow less ships to be launched per year while maintaining a full complement on the station. It would consist of a service module on the aft, an unpressurized propellant cluster of six tanks on the center, a pressurized module with docking adapter on the fore and a truss structure connecting all the parts.

It would use the reaction control system of the Progress-MS and an orbital manoeuvring rocket engine developed for another spacecraft. The new design would have a single deposit of propellant that could be used by the spacecraft or to refuel the space station. Comparison of space station cargo vehicles Progress spacecraft – an expendable cargo vehicle in use by the Russian Federal Space Agency Automated Transfer Vehicle – a retired expendable cargo vehicle used by the ESA Cygnus spacecraft – an expendable cargo vehicle developed by Northrop Grumman under American CRS program in use. H-II Transfer Vehicle – an expendable cargo vehicle in use by JAXA Dream Chaser Cargo System - a cargo variant of the reusable SNC's spaceplane Dragon cargo spacecraft - a reusable cargo vehicle developed by SpaceX, under American CRS program in use. RussianSpaceWeb TGK PG

2013 Acropolis Rally

The 2013 Acropolis Rally was the sixth round of the 2013 World Rally Championship season. The event was based in Loutraki and started on 31 May and was concluded on 2 June after fourteen special stages, totaling 306 competitive kilometres. Jari-Matti Latvala took his first win of the 2013 season, his first win for Volkswagen on the Acropolis Rally; the opening forty-seven kilometre stage proved to be difficult, claiming three high-profile victims in Sébastien Ogier, Mads Østberg and Mikko Hirvonen in short order, Evgeny Novikov emerged as the surprise early leader, building up a thirty-second advantage at the end of the first leg. The Russian's lead was short-lived, as he developed a puncture early in the second leg and was forced to limp back to the service park. Latvala took control of the rally while Andreas Mikkelsen in the third factory-supported Polo R began to work his way up through the points-paying positions, he missed out on a podium finish of his own, as Dani Sordo and Thierry Neuville each took their second podium finish of the season with second and third place respectively.

Latvala's result was challenged by Citroën, who believed his car was in violation of the technical regulations, but the protest was dismissed and Latvala's result was confirmed, allowing him to secure second place in the drivers' championship standings behind team-mate Ogier. Eleven World Rally Cars were entered into the event, as were sixteen WRC-2 entries and tend for the JWRC

Parkhill Mill

The Parkhill Mill is an historic mill complex at 1 Oak Hill Road in Fitchburg, Massachusetts. Built between 1885 and 1915, it was one of three mill complexes of the Parkill Company, one of the city's largest employers of the period; the mill complex was added to the National Register of Historic Places in 2008. The complex has been restored and is used by a variety of public and private businesses, as residential space; the Parkhill Mill complex is located west of downtown Fitchburg, on the south bank of the Nashua River east of Oak Hill Road and north of Cleghorn Street. The complex consists of four buildings. Other features of the complex include its original brick chimney stack, a former railroad bridge spanning the Nashua River; the main mill buildings are four stories in height, are built out of red brick. Windows are set in segmented-arch openings, the roof is of low pitch, with a projecting eave adorned with exposed rafters; the oldest portion of the complex, part of the U's base, was built in 1885 by Andrew Cleghorn, a Scottish immigrant who operated it as a textile mill.

He sold the mill to John Parkhill, his brother-in-law, in 1889. Parkhill was a Scottish immigrant who had worked for many years in the mills of Adams, Massachusetts. Parkhill had begun his business in a former chair factory in 1879, expanded into a second complex in Fitchburg in 1887 before buying this one; the Parkhill Manufacturing Company principally produced gingham fabrics, at its peak employed more than 1,000 people. This mill complex include two other buildings, which were located in the central space of the U, now occupied by a parking lot for the building tenants and visitors. National Register of Historic Places listings in Worcester County, Massachusetts

Heinz Pototschnig

Heinrich "Heinz" Pototschnig was an Austrian writer and physician. Pototschnig was born in Graz. After World War II and after he graduated in medicine, he moved to Carinthia, where he practised in Villach and started writing, his works include narratives, lyric poetry and radio plays. In 1962 he became editor of Der Bogen, edited by Hans Leb before. In 1977 he participated in the first edition of Klagenfurt, he died in Villach. Theodor Körner Prize, 1965 and 1971 Peter Rosegger Prize, 1969 Great golden decoration of Styria, 1984 Cultural award of Villach, 1994 Schatten schrägen ins Licht. Gedichte. 1961 Nachtkupfer, 1962 Den Rest teilen die Sterne, 1963 Lotungen. Lyrische Legende für Stimmen. 1965 Die grünen Schnäbel - Zehn Geschichten über Kinder. 1970 Die Grenze, 1974 Die Wanderung, 1976 Der Sommer mit den Enten, 1977 Westdrift. Gedichte. 1990 Aus Spiegeln keine Wiederkehr, 1991 Sei Stein und allein, 1994 Nach dem Abschied, 1997 Heinz Pototschnig in the German National Library catalogue