title: Chai Vang

text: By that time Vang was chasing Joey Crotteau, who fled down a trail. Vang sprinted to cut the corner to the trail to close the gap, and shot him in the lower back at about 65 yards. Vang reloaded, approached closer as Crotteau struggled forward, and shot him again. Vang then closed in and shot him twice more from behind, putting the final shot into his head.


title: Chai Vang

text: Vang, after reversing his blaze-orange jacket to its camo side, hid near a curve in the trail when he heard the ATV approaching. Thinking Jessica and Laski were likely armed and looking for him, Vang waited until they passed. When he fired, the bullet struck Jessica in the left buttock, and struck Laski, shattering his lower spine and abdomen. Vang ran over, shot Laski through the back, and then stepped behind Jessica, and fired a shot through her neck. Vang returned to retrieve his scope and leave. As he neared the site, he and Hesebeck came face to face. Vang said, “You're not dead yet?” and raised his rifle to shoot. He fired as Hesebeck grabbed Willers’ rifle with his right hand and dove for cover. Shots zipped past over Hesebeck’s head.


title: Chai Vang

text: Though he could point but not aim the rifle because of his wounded left arm, Hesebeck tried to shoot back. But when he pulled the trigger, the safety was still engaged. He dragged the unfamiliar rifle alongside his body to feel for the safety, and pushed it in. He pointed it again and fired once. He then heard a slight metallic sound from Vang’s rifle, and realized Vang was out of bullets.


title: Chai Vang

text: Vang fled the scene on foot and discarded his remaining ammunition, later stating that he did not want to shoot anyone else. Vang eventually came across another hunter riding an ATV (who had no affiliation with the victims), and this hunter offered to give him a ride, eventually taking him to Vang's cabin. Vang was arrested when he returned to his cabin five hours after the shooting. An officer waiting for Vang placed him into custody and transported him to the Sawyer County Jail. His bail was set at $2.5 million.


title: Chai Vang

text: The victims were part of a group of about 15 people who made an annual opening-weekend trip to the Crotteau-Willers property. Among those killed were father and son Robert and Joey Crotteau and Willers' daughter Jessica Willers.


title: Chai Vang

text: There have been conflicting reports about what may have led to the shootings. According to subsequent oral statements by Vang, one of the local hunters, Terry Willers, took the first shot at him from about 100 feet (30 m) away, and therefore the shootings were in self-defense. No shell casing was ever recovered from Willers' gun even though during the trial Hesebeck admitted to firing a single shot later during the incident when Vang, noticing that Hesebeck was still alive, fired at him again. Hesebeck testified no shot was fired before Vang started shooting. Additional forensic analysis of Willers' gun was not performed by the local law enforcement which caused the court to take a break from trial. The statements of both Vang and Hesebeck state that Vang removed the scope from his rifle before firing his first shot. Vang stated that race was a factor, alleging that during the verbal dispute, some of the local hunters yelled out racial slurs at him such as "chink" and "gook." On the stand, Hesebeck admitted that Robert Crotteau had called Vang a "Hmong a--hole." Hesebeck also admitted that he told law enforcement that Robert Crotteau had problems with trespassers in the past, specifically citing Hmong hunters, who often travel to Wisconsin from Minnesota to hunt. The term "Mud Duck" is often used in Western Wisconsin to refer to Minnesota residents, similar to "Cheesehead" being used to describe Wisconsin residents. Willers used this term to describe Chai Vang when he radioed back to the cabin. Though the term does not necessarily have a racial connotation, the defense argued that it did, due to the fact that Willers and the others did not know at the time that Vang was from Minnesota.


title: Chai Vang

text: The criminal complaint states that Vang shot four of his attackers in the back, and Vang himself admits he shot one attacker in the back. He also shot many of them multiple times. The prosecution made use of these facts in arguing against the claim of self-defense.


title: Chai Vang

text: The trial of Chai Soua Vang began Saturday, September 10, 2005 at the Sawyer County Courthouse in Hayward. Due to pre-trial publicity within the Twin Cities and Duluth-Superior media markets, twelve jurors and two alternates were selected from Dane County, and transported by bus approximately northwest to Sawyer County, where they were sequestered.


title: Chai Vang

text: Vang told the jury he feared for his life and began firing only after another hunter's shot nearly hit him. He detailed for the jurors how the other hunters approached him, and how he responded by shooting at each one. He says he shot two of the victims in the back because they were "disrespectful." He recounted with clarity how he killed each victim. While saying on the stand, "(he wished) it wasn't happening," Vang contended that three of the hunters deserved to die:


title: Chai Vang

text: Vang further testified that Joseph Crotteau deserved to die "because he accused me of giving him the finger and tried to cut in front of me to stop me from leaving." And Laski deserved to die because he had a gun & was using it to threaten a life, he said. Vang re-enacted his deeds while on the stand, using his hands and arms to imitate the motions of firing a rifle. Vang's lawyers commented that some of his abnormal remarks were due to the language barrier. Therefore, when Vang responded affirmatively to the question that Mr. Crotteau and Mr. Laski "deserved to die," his meaning implied that the men contributed to the circumstances that led to their deaths.


title: Chai Vang

text: On September 16, 2005, Chai Soua Vang was found guilty of all six charges of first degree intentional homicide and three charges of attempted homicide. On November 8, 2005, he was sentenced to six consecutive life terms plus seventy years (forty for two counts of attempted homicide plus five additional years for each count of homicide in the first degree); a sentence of life without parole. At the time, Wisconsin was one of 12 states in the United States that did not have the death penalty.


title: Narvik

text: Narvik is located on the shores of the Ofotfjorden. The municipality is part of the traditional district of Ofoten of Northern Norway, inside the Arctic Circle. The municipality of Narvik borders the municipality of Hamarøy to the southwest, Evenes to the northwest, Bardu, Gratangen, Lavangen and Tjeldsund (in Troms og Finnmark county) to the north, and Norrbotten County (Lapland) in Sweden to the south and east.


title: Narvik

text: The municipality is the 10th largest by area out of the 356 municipalities in Norway. Narvik is the 57th most populous municipality in Norway with a population of 21,530. The municipality's population density is and its population has decreased by 2% over the previous 10-year period.


title: Narvik

text: The municipality of Narvik was established on 1 January 1902 when the village of Narvik received status as a proper town and was separated from the large municipality of Ankenes. Initially, the town-municipality of Narvik had 3,705 residents. On 1 January 1974, the municipality of Ankenes was merged with the town-municipality of Narvik, forming a new, larger municipality of Narvik. After the merger, the new municipality of Narvik had 19,780 residents. On 1 January 1999, a small area of Narvik Municipality (population: 9) was transferred to the neighboring Evenes Municipality.


title: Narvik

text: On 1 January 2020, the municipality of Narvik was merged with the neighboring Ballangen Municipality and the eastern half of Tysfjord Municipality to form a new, larger municipality of Narvik. This occurred because in 2017, the municipal government agreed to the merger and the Parliament of Norway required Tysfjord to be split up.


title: Narvik

text: The coat of arms was adopted on 20 June 2019 for use starting in 2020. The arms are blue with a white image of the mountain Stetind. The arms were designed by Eirik Djupvik.


title: Narvik

text: The old arms were granted on 1 June 1951. The arms showed a gold-coloured anchor on a red background. The anchor symbolises Narvik's status as an important port (the largest harbour in North Norway).


title: Narvik

text: Narvik is named after the old "Narvik" farm ("Narduigh" – 1567), since the town is built on its ground.


title: Narvik

text: The Old Norse form of the port was probably "*Knarravík", The first element is the genitive pluralis of "knarr" 'merchant ship' – the last element is "vík" 'inlet'. The name "Knarravík" (modern forms "Knarvik" or "Narvik") is found several places along the Norwegian coast (and three places in the old Norwegian province of Bohuslän), and it refers to good, natural ports.


title: Narvik

text: The port was once called "Victoriahavn" after Queen Victoria of the United Kingdom, however Sweden's Crown Princess Victoria was also honoured.


title: Narvik

text: The history of Narvik as a settlement began in the Bronze Age. Not very much is known about these people, but the Vikings lived in this area.


title: Narvik

text: Narvik was developed as an all-year ice free port for the Swedish Kiruna and Gällivare iron mines. The history of modern Narvik begins in the 1870s, when the Swedish government began to understand the potential of the iron ore mines in Kiruna, Sweden. Obtaining iron ore from Kiruna had one significant problem in that there was no suitable Swedish port. The nearest Swedish port, Luleå, had limitations. It was covered with ice all winter, it is far from Kiruna, and it allows only medium-sized bulk freight vessels. Narvik offered a port which is ice-free thanks to the warm Gulf Stream, and is naturally large, allowing boats of virtually any size to anchor, up to long and deep. The Swedish company "(Gällivarre Aktiebolag)" built the Iron Ore Line ("Malmbanan") to Riksgränsen on the Norway–Sweden border. The Norwegian Ofotbanen railway line connects Narvik to the Swedish border.


title: Narvik

text: Swedish mining corporation LKAB still ships the majority of its ore from Narvik (a total 25 million tons a year). It is an important employer and landowner in Narvik, although its influence is not as prominent as in the past.


title: Narvik

text: The port of Narvik proved to be strategically valuable in the early years of World War II and the town became a focal point of the Norwegian Campaign. In 1939, Germany's war industry depended upon iron ore mined in Kiruna and Malmberget in Sweden. During the summer season, this ore could be sent by cargo ship to Germany through the Baltic Sea via the Swedish port of Luleå on the Gulf of Bothnia. However, when the Gulf of Bothnia froze during the winter, more shipments of the ore needed to be transported through Narvik and, from there, down the west coast of Norway to Germany. The town of Narvik is linked by rail to Sweden, but not to any other towns in Norway. As a result, Narvik serves as a gateway to the ore fields of Sweden that cannot be easily reached from southern Norway via land. Winston Churchill realized that the control of Narvik meant stopping most German imports of iron ore during the winter of 1940. This would be advantageous to the Allies, and it might help shorten the war. Equally as important, later in the war, German submarines and warships based there threatened the allied supply line to the Soviet Union.


title: Narvik

text: Churchill proposed laying a naval minefield in Norwegian territorial waters around Narvik (referred to as "the Leads"), or else occupying the town with Allied troops. The Allies hoped that they might be able to use an occupied Narvik as a base from which to secure the Swedish ore fields and/or to send supplies and reinforcements to Finland, then fighting the Finnish Winter War with the Soviet Union. Plans to lay a minefield around Narvik or to seize the town met with debate within the British government – since both plans would mean a violation of Norway's neutrality and sovereignty.


title: Narvik

text: Finally, on 8 April 1940, the British Admiralty launched Operation Wilfred, an attempt to lay anti-shipping minefields around Narvik in Norwegian territorial waters. Coincidentally, Germany launched its invasion of Norway (Operation Weserübung) on the next day. During this invasion, ten German destroyers, each carrying 200 mountain infantry soldiers, were sent to Narvik. The outdated Norwegian coastal defence ships and attempted to resist the invasion, but both Norwegian warships were sunk after a short and uneven battle. The Royal Navy quickly dispatched several ships to Narvik, including the battleship , and during the Battles of Narvik, the British took control of the coast, destroying the German destroyers that had brought the invasion force to Narvik, as well as other German ships in the area.


title: Narvik

text: On 12 April 1940, the first convoys of Allied soldiers were sent under Major-General Pierse Joseph Mackesy to Narvik. The Admiralty urged Mackesy to conduct an assault on Narvik from the sea as soon as possible. However, Mackesy believed that the German harbour defences were too strong for such an invasion to take place. The Admiralty argued that a naval bombardment of Norway would enable the troops to land safely, but General Mackesy refused to subject Norwegian citizens to such a bombardment, and instead he chose to land his troops near Narvik and wait until the snow melted to take over the town.


title: Narvik

text: Coordinated by the Norwegian General Carl Gustav Fleischer, Norwegian, French, Polish, and British forces recaptured Narvik on 28 May 1940. This is also considered the first Allied infantry victory in World War II. However, by that time, the Allies were losing the Battle of France and the evacuation from Dunkirk was underway. Since the Nazi German invasion of France had made Scandinavia largely irrelevant, and since the valuable troops assigned to Narvik were badly needed elsewhere, the Allies withdrew from Narvik on 8 June 1940 in Operation Alphabet. The same day, while operating in the Narvik area, the German battleships and sank the British aircraft carrier during the withdrawal from this battle. Without support from the Allied naval task force, the Norwegians were outnumbered, and they had to lay down their arms in Norway on 10 June 1940. This was not a complete capitulation, since the Norwegians kept on fighting guerrilla operations inland.


title: Narvik

text: Possession of the Ofotfjord was also important to the German Kriegsmarine (navy) since it provided a refuge for warships like the "pocket battleship" and the battleship outside the range (at the time) of air attacks from Scotland. Also, possibly U-boats could be based at Narvik.


title: Narvik

text: The municipality is governed by a municipal council of elected representatives, which in turn elect a mayor. The municipality falls under the Ofoten District Court and the Hålogaland Court of Appeal.


title: Narvik

text: The municipal council () of Narvik is made up of 41 representatives that are elected to four year terms. The party breakdown of the council is as follows:


title: Narvik

text: The municipality of Narvik covers large areas outside the town itself. Some of the other settlements in the municipality are Bjerkvik (located at the head of the Herjangsfjord), Håkvik, Beisfjord (along the Beisfjorden) and Skjomen. The eastern part, towards the border with Sweden, is dominated by mountains, and Storsteinfjellet reaches . There are also valleys and lakes, including the lakes Gautelisvatnet, Hartvikvatnet, Indre Sildvikvatnet, Iptojávri, Kjårdavatnet, Lossivatnet, Sealggajávri and Unna Guovdelisjávri.


title: Narvik

text: The town itself is situated near the innermost part of the deep Ofotfjorden, but even here the mountains, going almost straight up from the blue fjord, reach as high as in Skjomen, where the glacier Frostisen can be seen. Other fjords in Narvik include Skjomen, Beisfjorden, Herjangsfjorden, and Rombaken.


title: Narvik

text: Forests cover the lower parts of the mountains (below 500 metres), but near the summits, the snow can stay most of the summer. Narvik has well prepared slopes for alpine skiing, some of which end almost in the town centre.


title: Narvik

text: Narvik features a boreal climate (Köppen climate classification: Dfc) with mild winters for this climate type, or a subpolar oceanic climate (Cfc), depending on winter threshold ( as used in the US or as in the original classification). It is close to a humid continental climate due to a mild September.


title: Narvik

text: As Narvik is inside the arctic circle, the climate is very mild for the latitude. The mountains surrounding the town give shelter from some of the strong winds typical for coastal areas, but the easterlies can be strong with especially strong wind gusts.


title: Narvik

text: The all-time high was set 9 July 2014. July 2014 is warmest month on record with mean and average daily high . The all-time low was recorded on 1 February 1980. Coldest month on record is February 1966 with mean and average daily low . The average date for the first overnight freeze in autumn when the low goes below is October 13 (1981-2010).


title: Narvik

text: The light varies considerably in Narvik since the sun is below the horizon from late November until mid-January; when there is only a bluish light for a few hours around noon. The mountains surrounding the town in reality extend this period from early November until the end of January. The light is often intense in March and April, with long daylight hours and snow cover since the snow melts in lowland areas in April, but stays in the mountains for several months. The "midnight sun" is above the horizon from 25 May to 20 July (57 days), and the period with continuous daylight lasts a bit longer, from approximately 10 May to the end of July, polar night from 5 December to 6 January (33 days). There is also a transitional period with twilight in the night, so it is not possible to see any stars at night from the last days of April until early August.


title: Narvik

text: The town of Narvik is a commercial centre for some of the neighbouring municipalities. Narvik University College has approximately 1,200 students. There are some high-tech businesses in Narvik (among them Natech ) and the largest research institute in Northern Norway, Norut Narvik.


title: Narvik

text: Narvik was one of the first areas in the world to be affected by the financial crisis of 2007–2008. It lost the equivalent of $18 million in August 2007 after it invested in Citigroup securities. As the Norwegian government refused to bail them out, Narvik was forced to implement severe budget cuts.


title: Narvik

text: Narvik has access to numerous outdoor activities. This is the best known location in northern Norway for alpine skiing.


title: Narvik

text: There are lifts, and several of the slopes are floodlit. There is also a cable car to Fagernesfjellet, with a view and the possibility to walk even higher up in the mountains. Narvik Winter Festival () takes place in early March. Mountain hiking is very popular in the area, and the mountain area near the Swedish border has several places of accommodation. A signed mountain bike route is also available. Wreck diving attracts divers to Narvik, as there are a lot of wrecks in or near the harbour, and more spread out in the fjord. Fishing in the fjord or in lakes and streams is a popular leisure activity. There are salmon rivers in Skjomen, Beisfjord and Bjerkvik.


title: Narvik

text: The port of Narvik is ice-free and well protected from the weather. The port consists of three waterfront sections: LKAB bulk port, central port area with piers and deep-water harbor at Fagernes with intermodal facilities. Approximately of cargo are annually shipped from the ports of Narvik. By 2015, the port had handled 1.1 billion tonnes of ore. Most of this iron ore. In 2015 the port installed a pier with 18 suction cups to moor ships, expected to save 40 minutes of mooring time. Each cup is 2x2 meters.


title: Narvik

text: A present and historical key to land transportation to Narvik is the Ofoten Line railway from northern Sweden across the mountains to this port town. Goods like iron ore shipped via this railroad make Narvik an important seaport. The railway has stops at Bjørnfjell Station, Katterat Station, Søsterbekk Station, and Narvik Station.


title: Narvik

text: European route E6 crosses through the municipality using three bridges: Skjomen Bridge, Beisfjord Bridge and Hålogaland Bridge. There is also the Rombak Bridge used for E6 until 2018. There are road connections from Narvik across the mountains eastwards to Abisko and Kiruna, Sweden (via European route E10). One Narvik citizen lets other citizens use his Tesla cars at will.


title: Narvik

text: Narvik is served by Harstad/Narvik Airport, Evenes which is by road from Narvik and has regular flights to Oslo, Trondheim, Bodø, Tromsø and Andenes.


title: Narvik

text: The Narvik War Museum ("Narvik Krigsmuseum") covers the war years 1940–1945. The museum displays the Victoria Cross awarded posthumously to Captain Bernard Warburton-Lee of the British Royal Navy and a rare German Enigma coding machine.


title: Narvik

text: Museum Nord - Narvik tells of the development of the ice-free harbour of Narvik and the rapid transformation of the town over the past century. The building that houses Museum Nord - Narvik was erected in 1902 as the head office of the Norwegian state railway company, "Norges statsbaner" and was designed by architect, Paul Due.


title: Narvik

text: The Church of Norway has four parishes () within the municipality of Narvik. It is part of the Ofoten prosti (deanery) in the Diocese of Sør-Hålogaland.


title: Narvik

text: Narvik appeared in Battlefield V, a First-person shooter video game, based on WWII. The map's setting, in Narvik, specifically depicts the Allied landings at the city on the 28th of May. The setting's location, depicts a snowy, mountainside battlefield, featuring tanks, planes, and infantry. the playable area includes the rail yard, loading bay, town, and ore deposit.


title: Lil Peep discography

text: Lil Peep was an American recording artist who released two studio albums, five mixtapes, and fourteen extended plays throughout his lifetime.


title: Lil Peep discography

text: His studio album "Come Over When You're Sober, Pt. 1" was released in August 2017 and peaked at number thirty-eight on the "Billboard" 200. The album spawned four singles: "Benz Truck (гелик)", "The Brightside", "Awful Things" and "Save That Shit". In January 2018, his first posthumous single "Spotlight" with Marshmello was released. It was then followed by "4 Gold Chains" with Clams Casino and "Falling Down" with fellow deceased rapper XXXTentacion in the same year. Shortly after, the original version was released, "Sunlight on Your Skin", with a verse featuring American rapper, iLoveMakonnen.


title: Lil Peep discography

text: Peep's first posthumous project, "Come Over When You're Sober, Pt. 2", was announced in October 2018 and was released on November 9, 2018. The project had three singles: "Cry Alone", "Runaway" and a remix of the song "Life", which was renamed "Life Is Beautiful". Both "Falling Down" and "Sunlight on Your Skin" were added as bonus tracks to the deluxe version of "Come Over When You're Sober, Pt. 2".


title: Lil Peep discography

text: Peep's second posthumous project, "Everybody's Everything", released on November 15, 2019, the second anniversary of Peep's death. This album was also the official soundtrack to an accompanying documentary of the same name about the late Lil Peep's life. The album contained singles from regular collaborator, producer and friend BigHead, including a formal re-release of their hit "Witchblades" and an official release of "Liar" and "Aquafina" featuring Rich the Kid.


title: SeaTac, Washington

text: SeaTac is a city in southern King County, Washington, United States. The city is an inner-ring suburb of Seattle and part of the Seattle metropolitan area. The name "SeaTac" is derived from the Seattle–Tacoma International Airport, itself a portmanteau of Seattle and Tacoma.


title: SeaTac, Washington

text: The city of SeaTac is in area and has a population of 31,454 according to the 2020 census. The city boundaries surround the Seattle–Tacoma International Airport (approximately in area), which is owned and operated by the Port of Seattle. The city includes the communities of Angle Lake, Bow Lake, McMicken Heights and Riverton Heights, which were established before the city's incorporation. Residents voted for incorporation on March 14, 1989, and the city incorporated in February 1990.


title: SeaTac, Washington

text: The Highline area, which includes modern-day SeaTac, Burien, most of Des Moines, and unincorporated communities such as White Center and Boulevard Park, was settled by Americans in the mid-1850s. The federal government finished construction of a military road from Fort Steilacoom to Fort Bellingham in 1860, passing through the Highline area to the east of modern-day SeaTac. One of the more prominent roads of travel from Seattle to Tacoma early in the 20th century is Des Moines Memorial Drive (originally called the High Line road), which passes directly through the middle of the region, particularly through SeaTac and Burien especially.


title: SeaTac, Washington

text: Incorporating the area as a city was proposed by local residents in the 1980s, while a competing proposal sought annexation into Des Moines or another city. Local residents voted for incorporation on March 14, 1989, and the city incorporated on February 28, 1990. Des Moines amended their annexation territory following the decision. The original ballot used the name "Sea-Tac", but the incorporation petition to the county government omitted the hyphen. In 2014, Gavin Kelly of The Resolution Foundation wrote that "A generation ago SeaTac was what Americans would call a middle-class town. A jet-fueller or baggage handler could earn a decent living."


title: SeaTac, Washington

text: SeaTac is governed by a city council which consists of seven elected councilpersons. The city "has contracted with the King County Sheriff's Office for law enforcement since incorporation in 1990." Deputies assigned to SeaTac wear city uniforms and drive patrol cars marked with the city logo. There are currently 51 patrol officers, detectives, and support staff assigned full-time to the city.


title: SeaTac, Washington

text: In January 2014 the SeaTac Fire Department entered a 20-year contract with Kent Fire Department Regional Fire Authority (RFA) to form the Puget Sound Regional Fire Authority. SeaTac's three fire stations, Station 45, 46, and 47, joined Kent's Station 73 to make up RFA's West Battalion.


title: SeaTac, Washington

text: The Seatac Municipal Court, located in the City Hall, is a court of limited jurisdiction. The judge is authorized by the Revised Code of Washington to preside over civil infractions, traffic infractions, criminal misdemeanor and gross misdemeanor violations, and civil orders for protection.


title: SeaTac, Washington

text: Public Works is responsible for planning, design, construction and maintenance of streets, transportation improvements, surface water utility, and solid waste and recycling programs.


title: SeaTac, Washington

text: In 2013, voters in the city narrowly passed a minimum wage of $15 per hour for employees of airport-related businesses, such as hotels, parking lots and car rental agencies. In a later appeals court decision, the $15 minimum wage was reversed for employees working entirely on Port of Seattle property within the city limits but still applies to employees of airport-related businesses in the city proper. Union workshops are exempt from the $15 minimum wage. However, the Washington Supreme Court in August 2015 reversed the King County Superior Court ruling, which said that SeaTac did not have authority to set a minimum wage at the airport. The Supreme Court rejected the argument that the wage did not apply because the airport is owned by the Port of Seattle. The Court stated that Proposition 1 can be enforced at Seattle–Tacoma International Airport because there is no indication that it will interfere with airport operations and that federal labor law does not preempt the provision protecting workers from retaliation.


title: SeaTac, Washington

text: The city is home to over 900 licensed businesses, nearly 80 of which are Fortune 1000 companies. They employ nearly 40,000 employees in the city of SeaTac and generate local sales of approximately $3.7 billion.


title: SeaTac, Washington

text: Alaska Airlines and Horizon Air are headquartered in the city. Four airlines have operations at 18000 Pacific Highway South (also known as 18000 International Boulevard) in the city, including Asiana Airlines, EVA Air, Hainan Airlines, and China Airlines.


title: SeaTac, Washington

text: SeaTac's Department of Community and Economic Development was formed in early 2011 to create a one-stop permitting center, increase the level of service and assist in the facilitation of economic development by creating a more cohesive approach to real estate development and job creation. The new department has four divisions: Economic Development, Planning, Engineering Review, and Building Services.


title: SeaTac, Washington

text: In 2013, the City of SeaTac Proposition No. 1 passed with 50.64% of the vote to raise the minimum wage to $15 per hour.


title: SeaTac, Washington

text: According to the United States Census Bureau, the city has a total area of , of which, is land and is water.


title: SeaTac, Washington

text: As of 2000 the median income for a household in the city was $41,202, and the median income for a family was $47,630. Males had a median income of $34,396 versus $28,984 for females. The per capita income for the city was $19,717. About 9.8% of families and 11.5% of the population were below the poverty line, including 15.5% of those under age 18 and 8.1% of those age 65 or over.


title: SeaTac, Washington

text: SeaTac's population has grown steadily since the 2000 Census, and is projected to grow 5.06% by 2022, a rate higher than the US rate of 3.77%, but lower than King County's 7.46%. SeaTac has considerable ethnic diversity. Only 51.76% of the age 5+ population reportedly spoke only English at home; some 13.90% spoke Spanish at home, considerably higher than King County's 6.82%, but only somewhat higher than the US's overall 13.16%. Languages spoken at home also include those from Asia-Pacific at 10.74%, Indo-European languages at 10.06%, and other languages at 13.54%.


title: SeaTac, Washington

text: As of the census of 2010, there were 26,909 people, 9,533 households, and 5,913 families residing in the city. The population density was . There were 10,360 housing units at an average density of . The racial makeup of the city was 45.9% White (39.5% Non-Hispanic White), 16.8% African American, 1.5% Native American, 14.5% Asian, 3.6% Pacific Islander, 11.6% from other races, and 6.0% from two or more races. Hispanic or Latino of any race were 20.3% of the population.


title: SeaTac, Washington

text: There were 9,533 households, of which 33.2% had children under the age of 18 living with them, 40.6% were married couples living together, 14.0% had a female householder with no husband present, 7.4% had a male householder with no wife present, and 38.0% were non-families. 28.8% of all households were made up of individuals, and 7.5% had someone living alone who was 65 years of age or older. The average household size was 2.72 and the average family size was 3.38.


title: SeaTac, Washington

text: The median age in the city was 34.5 years. 23.1% of residents were under the age of 18; 10.3% were between the ages of 18 and 24; 31.8% were from 25 to 44; 25.2% were from 45 to 64; and 9.7% were 65 years of age or older. The gender makeup of the city was 52.4% male and 47.6% female.


title: SeaTac, Washington

text: Highline Public Schools is the school district with the majority of the city in its boundaries. Elementary schools serving the Highline sections of the city include Bow Lake Elementary School in SeaTac, Madrona Elementary School in SeaTac, McMicken Heights Elementary School in SeaTac, and Cedarhurst Elementary School in Burien. Most residents are zoned to Chinook Middle School and Tyee Educational Complex in the city, while some are zoned to Sylvester Middle School and Highline High School in Burien. With the opening of Glacier Middle School in north SeaTac, residents north of the airport are generally zoned there and subsequently to Highline High School given the proximity of that area to Burien.


title: SeaTac, Washington

text: Tyee Educational Complex housing three independent schools: The Academy of Citizenship and Empowerment, and Odyssey: The Essential School. It then has been transformed back to Tyee High School - a single school in the 2017–18 school year.


title: SeaTac, Washington

text: In 2004, Highline Public Schools reorganized some of its high schools, including Tyee, into having smaller programs on larger campuses.


title: SeaTac, Washington

text: Angle Lake Park, a park at Angle Lake, has a barbecue area, a boat launch, a fishing pier, playground equipment, an open recreation area, swimming facilities, a stage, toilet facilities, and a spray park. In the swimming area lifeguards are on duty during the summer months.


title: SeaTac, Washington

text: Des Moines Creek Trail Park, consisting of , has a paved trail for bicyclists and pedestrians; off-street parking spaces are located at the trail head.


title: SeaTac, Washington

text: The Grandview Park, an off leash dog area, has open areas, benches, fencing, a kiosk, waste receptacles, "sani-cans," and trails.


title: SeaTac, Washington

text: The Neighborhood Park at SeaTac Community Center has a half court basketball court a skate park, playground equipment, a picnic area, a climbing boulder, and parking.


title: SeaTac, Washington

text: The North SeaTac Park has the SeaTac Community Center, baseball, soccer (football), and softball fields, a disk golf course, an outdoor basketball court, an open area, playground equipment, a picnic shelter, toilet facilities, BMX track and paved walking trails.


title: SeaTac, Washington

text: The Sunset Park has baseball/softball fields, soccer fields, tennis courts, toilet facilities, and paved walking trails.


title: SeaTac, Washington

text: The Valley Ridge Park has baseball/softball fields with synthetic turf, outdoor basketball courts, a community center, a hockey court, playground equipment, a skate park, soccer fields with synthetic turf, tennis courts, toilet facilities.


title: SeaTac, Washington

text: The Tyee Valley Golf Course is an 18-hole golf course and also served as the 1988 and 1989 USA Cross Country Championships running course.


title: SeaTac, Washington

text: SeaTac is served by three major highways: State Route 99 (International Boulevard), State Route 518, and the Airport Expressway. Portions of Interstate 5 and State Route 509 also lie within the city limits.


title: SeaTac, Washington

text: The city is also served by several public transportation services: Link light rail stops at two stations in the city, at SeaTac/Airport station and Angle Lake station; King County Metro operates several bus routes in the area, including the RapidRide A Line on International Boulevard and RapidRide F Line on Southcenter Boulevard; some Sound Transit Express regional bus routes terminate or serve the SeaTac area, primarily the airport and other transit hubs.


title: Nixon's Enemies List

text: "Nixon's Enemies List" is the informal name of what started as a list of President of the United States Richard Nixon's major political opponents compiled by Charles Colson, written by George T. Bell (assistant to Colson, special counsel to the White House), and sent in memorandum form to John Dean on September 9, 1971. The list was part of a campaign officially known as "Opponents List" and "Political Enemies Project".


title: Nixon's Enemies List

text: The list became public knowledge on June 27, 1973, when Dean mentioned during hearings with the Senate Watergate Committee that a list existed containing those whom the president did not like. Journalist Daniel Schorr, who happened to be on the list, managed to obtain a copy of it later that day.


title: Nixon's Enemies List

text: A longer second list was made public by Dean on December 20, 1973, during a hearing with the Congressional Joint Committee on Internal Revenue Taxation.


title: Nixon's Enemies List

text: The official purpose, as described by the White House Counsel's Office, was to "screw" Nixon's political enemies, by means of tax audits from the Internal Revenue Service, and by manipulating "grant availability, federal contracts, litigation, prosecution, etc." In a memorandum from John Dean to Lawrence Higby (August 16, 1971), Dean explained the purpose of the list:


title: Nixon's Enemies List

text: The twenty names in the memo were as follows, although a master list of Nixon's political opponents with additional names was developed later.


title: Nixon's Enemies List

text: According to Dean, Colson later compiled hundreds of names on a "master list" which changed constantly. On December 20, 1973, the Congressional Joint Committee on Internal Revenue Taxation concluded that people on the "Enemies" list had "not" been subjected to an unusual number of tax audits. The report revealed a second list of about 576 (with some duplicates) supporters and staffers of George McGovern's 1972 presidential campaign given to Internal Revenue Commissioner Johnnie Walters by John Dean on September 11, 1972. "The Washington Post" printed the entire list the next day, but "The New York Times" reported just a few paragraphs on page 21.


title: Nixon's Enemies List

text: Newsman Daniel Schorr and actor Paul Newman stated, separately, that inclusion on the list was their greatest accomplishment. When this list was released, Schorr read it live on television, not realizing that he was on the list until he came to his own name. Author Hunter S. Thompson remarked he was disappointed he was not on it.


title: Nixon's Enemies List

text: In the United States, the term "enemies list" has come to be used in contexts not associated with Richard Nixon. For example, satirist P. J. O'Rourke's 1989 "A Call for a New McCarthyism" in "The American Spectator" has a hybrid blacklist and enemies list, suggesting that, contrary to the spirits of these lists, the subjects there should be overexposed, not suppressed, "so that a surfeited public rebels in disgust."


title: Nixon's Enemies List

text: In Philip Roth's "Our Gang", which was published in 1971, two years before the list was first mentioned in public, the Nixon parody character Trick E. Dixon begins to compile a rudimentary list of five political enemies. It includes Jane Fonda and the Black Panthers who were on the real-life expanded master list, The Berrigans (who were not) and Curt Flood.


title: Nixon's Enemies List

text: In "Homer's Enemy" (1997), an 8th-season episode of "The Simpsons", Moe Szyslak shows off his own enemies list, which Barney Gumble quickly appraises as Nixon's list, with the latter's name crossed out and replaced with Moe's. Moe promptly adds Barney to the list for his insolence. A later episode made likely reference to the list when Homer falls from a shoddy chair that breaks, then remarks that the chair's manufacturer "just made the list!".


title: Nixon's Enemies List

text: In "Futurama"s first episode, "Space Pilot 3000" (1999), Fry and Bender walk through a room of live preserved heads of famous people. When Fry knocks over Nixon's jar, Nixon says "That's it, you just made my list!"


title: Nixon's Enemies List

text: In a "BoJack Horseman" second season episode called "The Shot" (2015), the title character and Todd visit the Nixon Presidential Library with the intent of stealing a scaled-down replica of the library. Mounted on the walls are Nixon's Enemy and "Frenemy" Lists. Walt Disney is included on the Enemy List.


title: Systems biology

text: Systems biology is the computational and mathematical analysis and modeling of complex biological systems. It is a biology-based interdisciplinary field of study that focuses on complex interactions within biological systems, using a holistic approach (holism instead of the more traditional reductionism) to biological research.


title: Systems biology

text: Particularly from the year 2000 onwards, the concept has been used widely in biology in a variety of contexts. The Human Genome Project is an example of applied systems thinking in biology which has led to new, collaborative ways of working on problems in the biological field of genetics. One of the aims of systems biology is to model and discover emergent properties, properties of cells, tissues and organisms functioning as a system whose theoretical description is only possible using techniques of systems biology. These typically involve metabolic networks or cell signaling networks.


title: Systems biology

text: As a field of study, particularly, the study of the interactions between the components of biological systems, and how these interactions give rise to the function and behavior of that system (for example, the enzymes and metabolites in a metabolic pathway or the heart beats).


title: Systems biology

text: As a paradigm, systems biology is usually defined in antithesis to the so-called reductionist paradigm (biological organisation), although it is consistent with the scientific method. The distinction between the two paradigms is referred to in these quotations: "the reductionist approach has successfully identified most of the components and many of the interactions but, unfortunately, offers no convincing concepts or methods to understand how system properties emerge ... the pluralism of causes and effects in biological networks is better addressed by observing, through quantitative measures, multiple components simultaneously and by rigorous data integration with mathematical models." (Sauer "et al.") "Systems biology ... is about putting together rather than taking apart, integration rather than reduction. It requires that we develop ways of thinking about integration that are as rigorous as our reductionist programmes, but different. ... It means changing our philosophy, in the full sense of the term." (Denis Noble)


title: Systems biology

text: As a series of operational protocols used for performing research, namely a cycle composed of theory, analytic or computational modelling to propose specific testable hypotheses about a biological system, experimental validation, and then using the newly acquired quantitative description of cells or cell processes to refine the computational model or theory. Since the objective is a model of the interactions in a system, the experimental techniques that most suit systems biology are those that are system-wide and attempt to be as complete as possible. Therefore, transcriptomics, metabolomics, proteomics and high-throughput techniques are used to collect quantitative data for the construction and validation of models.


title: Systems biology

text: As the application of dynamical systems theory to molecular biology. Indeed, the focus on the dynamics of the studied systems is the main conceptual difference between systems biology and bioinformatics.


title: Systems biology

text: As a socioscientific phenomenon defined by the strategy of pursuing integration of complex data about the interactions in biological systems from diverse experimental sources using interdisciplinary tools and personnel.


title: Systems biology

text: Systems biology was begun as a new field of science around 2000, when the Institute for Systems Biology was established in Seattle in an effort to lure "computational" type people who it was felt were not attracted to the academic settings of the university. The institute did not have a clear definition of what the field actually was: roughly bringing together people from diverse fields to use computers to holistically study biology in new ways. A Department of Systems Biology at Harvard Medical School was launched in 2003. In 2006 it was predicted that the buzz generated by the "very fashionable" new concept would cause all the major universities to need a systems biology department, thus that there would be careers available for graduates with a modicum of ability in computer programming and biology. In 2006 the National Science Foundation put forward a challenge to build a mathematical model of the whole cell. In 2012 the first whole-cell model of "Mycoplasma genitalium" was achieved by the Karr Laboratory at the Mount Sinai School of Medicine in New York. The whole-cell model is able to predict viability of "M. genitalium" cells in response to genetic mutations.


title: Systems biology

text: An earlier precursor of systems biology, as a distinct discipline, may have been by systems theorist Mihajlo Mesarovic in 1966 with an international symposium at the Case Institute of Technology in Cleveland, Ohio, titled "Systems Theory and Biology". Mesarovic predicted that perhaps in the future there would be such as thing as "systems biology". Other early precursors that focused on the view that biology should be analyzed as a system, rather than a simple collection of parts, were Metabolic Control Analysis, developed by Henrik Kacser and Jim Burns later thoroughly revised, and Reinhart Heinrich and Tom Rapoport, and Biochemical Systems Theory developed by Michael Savageau


title: Systems biology

text: According to Robert Rosen in the 1960s, holistic biology had become passé by the early 20th century, as more empirical science dominated by molecular chemistry had become popular. Echoing him forty years later in 2006 Kling writes that the success of molecular biology throughout the 20th century had suppressed holistic computational methods. By 2011 the National Institutes of Health had made grant money available to support over ten systems biology centers in the United States, but by 2012 Hunter writes that systems biology had not lived up to the hype, having promised more than it achieved, which had caused it to become a somewhat minor field with few practical applications. Nonetheless, proponents hoped that it might once prove more useful in the future.


title: Systems biology

text: An important milestone in the development of systems biology has become the international project Physiome.


title: Systems biology

text: According to the interpretation of systems biology as using large data sets using interdisciplinary tools, a typical application is metabolomics, which is the complete set of all the metabolic products, metabolites, in the system at the organism, cell, or tissue level.


title: Systems biology

text: Items that may be a computer database include: phenomics, organismal variation in phenotype as it changes during its life span; genomics, organismal deoxyribonucleic acid (DNA) sequence, including intra-organismal cell specific variation. (i.e., telomere length variation); epigenomics/epigenetics, organismal and corresponding cell specific transcriptomic regulating factors not empirically coded in the genomic sequence. (i.e., DNA methylation, Histone acetylation and deacetylation, etc.); transcriptomics, organismal, tissue or whole cell gene expression measurements by DNA microarrays or serial analysis of gene expression; interferomics, organismal, tissue, or cell-level transcript correcting factors (i.e., RNA interference), proteomics, organismal, tissue, or cell level measurements of proteins and peptides via two-dimensional gel electrophoresis, mass spectrometry or multi-dimensional protein identification techniques (advanced HPLC systems coupled with mass spectrometry). Sub disciplines include phosphoproteomics, glycoproteomics and other methods to detect chemically modified proteins; glycomics, organismal, tissue, or cell-level measurements of carbohydrates; lipidomics, organismal, tissue, or cell level measurements of lipids.


title: Systems biology

text: The molecular interactions within the cell are also studied, this is called interactomics. A discipline in this field of study is protein-protein interactions, although interactomics includes the interactions of other molecules. Neuroelectrodynamics, where the computer's or a brain's computing function as a dynamic system is studied along with its (bio)physical mechanisms; and fluxomics, measurements of the rates of metabolic reactions in a biological system (cell, tissue, or organism).


title: Systems biology

text: In approaching a systems biology problem there are two main approaches. These are the top down and bottom up approach. The top down approach takes as much of the system into account as possible and relies largely on experimental results. The RNA-Seq technique is an example of an experimental top down approach. Conversely, the bottom up approach is used to create detailed models while also incorporating experimental data. An example of the bottom up approach is the use of circuit models to describe a simple gene network.


title: Systems biology

text: Various technologies utilized to capture dynamic changes in mRNA, proteins, and post-translational modifications. Mechanobiology, forces and physical properties at all scales, their interplay with other regulatory mechanisms; biosemiotics, analysis of the system of sign relations of an organism or other biosystems; Physiomics, a systematic study of physiome in biology.


title: Systems biology

text: Cancer systems biology is an example of the systems biology approach, which can be distinguished by the specific object of study (tumorigenesis and treatment of cancer). It works with the specific data (patient samples, high-throughput data with particular attention to characterizing cancer genome in patient tumour samples) and tools (immortalized cancer cell lines, mouse models of tumorigenesis, xenograft models, high-throughput sequencing methods, siRNA-based gene knocking down high-throughput screenings, computational modeling of the consequences of somatic mutations and genome instability). The long-term objective of the systems biology of cancer is ability to better diagnose cancer, classify it and better predict the outcome of a suggested treatment, which is a basis for personalized cancer medicine and virtual cancer patient in more distant prospective. Significant efforts in computational systems biology of cancer have been made in creating realistic multi-scale "in silico" models of various tumours.


title: Systems biology

text: The systems biology approach often involves the development of mechanistic models, such as the reconstruction of dynamic systems from the quantitative properties of their elementary building blocks. For instance, a cellular network can be modelled mathematically using methods coming from chemical kinetics and control theory. Due to the large number of parameters, variables and constraints in cellular networks, numerical and computational techniques are often used (e.g., flux balance analysis).


title: Systems biology

text: Other aspects of computer science, informatics, and statistics are also used in systems biology. These include new forms of computational models, such as the use of process calculi to model biological processes (notable approaches include stochastic π-calculus, BioAmbients, Beta Binders, BioPEPA, and Brane calculus) and constraint-based modeling; integration of information from the literature, using techniques of information extraction and text mining; development of online databases and repositories for sharing data and models, approaches to database integration and software interoperability via loose coupling of software, websites and databases, or commercial suits; network-based approaches for analyzing high dimensional genomic data sets. For example, weighted correlation network analysis is often used for identifying clusters (referred to as modules), modeling the relationship between clusters, calculating fuzzy measures of cluster (module) membership, identifying intramodular hubs, and for studying cluster preservation in other data sets; pathway-based methods for omics data analysis, e.g. approaches to identify and score pathways with differential activity of their gene, protein, or metabolite members. Much of the analysis of genomic data sets also include identifying correlations. Additionally, as much of the information comes from different fields, the development of syntactically and semantically sound ways of representing biological models is needed.


title: Systems biology

text: Researchers begin by choosing a biological pathway and diagramming all of the protein interactions. After determining all of the interactions of the proteins, mass action kinetics is utilized to describe the speed of the reactions in the system. Mass action kinetics will provide differential equations to model the biological system as a mathematical model in which experiments can determine the parameter values to use in the differential equations. These parameter values will be the reaction rates of each proteins interaction in the system. This model determines the behavior of certain proteins in biological systems and bring new insight to the specific activities of individual proteins. Sometimes it is not possible to gather all reaction rates of a system. Unknown reaction rates are determined by simulating the model of known parameters and target behavior which provides possible parameter values.


title: Systems biology

text: The use of constraint-based reconstruction and analysis (COBRA) methods has become popular among systems biologists to simulate and predict the metabolic phenotypes, using genome-scale models. One of the methods is the flux balance analysis (FBA) approach, by which one can study the biochemical networks and analyze the flow of metabolites through a particular metabolic network, by maximizing the object of interest.


title: Chopper (electronics)

text: In electronics, a chopper circuit is any of numerous types of electronic switching devices and circuits used in power control and signal applications. A chopper is a device that converts fixed DC input to a variable DC output voltage directly. Essentially, a chopper is an electronic switch that is used to interrupt one signal under the control of another.


title: Chopper (electronics)

text: In power electronics applications, since the switching element is either fully on or fully off, its losses are low and the circuit can provide high efficiency. However, the current supplied to the load is discontinuous and may require smoothing or a high switching frequency to avoid undesirable effects. In signal processing circuits, use of a chopper stabilizes a system against drift of electronic components; the original signal can be recovered after amplification or other processing by a synchronous demodulator that essentially un-does the "chopping" process.


title: Chopper (electronics)

text: For all the chopper configurations operating from a fixed DC input voltage, the average value of the output voltage is controlled by periodic opening and closing of the switches used in the chopper circuit.


title: Chopper (electronics)

text: In pulse-width modulation the switches are turned on at a constant chopping frequency. The total time period of one cycle of output waveform is constant. The average output voltage is directly proportional to the ON time of chopper. The ratio of ON time to total time is defined as duty cycle. It can be varied between 0 and 1 or between 0 and 100%. Pulse-width modulation (PWM), or pulse-duration modulation (PDM), is a technique used to encode a message into a pulsing signal. Although this modulation technique can be used to encode information for transmission, its main use is to allow the control of the power supplied to electrical devices, especially to inertial loads such as motors. The average value of voltage (and current) fed to the load is controlled by turning the switch between supply and load on and off at a fast rate. The longer the switch is on compared to the off periods, the higher the total power supplied to the load. The PWM switching frequency has to be much higher than what would affect the load (the device that uses the power), which is to say that the resultant waveform perceived by the load must be as smooth as possible. Typically switching has to be done several times a minute in an electric stove, 120 Hz in a lamp dimmer, from few kilohertz (kHz) to tens of kHz for a motor drive and well into the tens or hundreds of kHz in audio amplifiers and computer power supplies.


title: Chopper (electronics)

text: In frequency modulation, pulses of a fixed amplitude and duration are generated and the average value of output is adjusted by changing how often the pulses are generated.


title: Chopper (electronics)

text: In current limit control (CLC) technique, duty cycle is controlled by controlling the load current between maximum and minimum values. The chopper is switched ON and OFF periodically so that the load current is maintained between predetermined maximum and minimum values.


title: Chopper (electronics)

text: One classic use for a chopper circuit and where the term is still in use is in "chopper amplifiers". These are DC amplifiers. Some types of signals that need amplifying can be so small that an incredibly high gain is required, but very high gain DC amplifiers are much harder to build with low offset and 1/formula_1 noise, and reasonable stability and bandwidth. It's much easier to build an AC amplifier instead. A chopper circuit is used to break up the input signal so that it can be processed as if it were an AC signal, then integrated back to a DC signal at the output. In this way, extremely small DC signals can be amplified. This approach is often used in electronic instrumentation where stability and accuracy are essential; for example, it is possible using these techniques to construct pico-voltmeters and Hall sensors.


title: Chopper (electronics)

text: The input offset voltage of amplifiers becomes important when trying to amplify small signals with very high gain. Because this technique creates a very low input offset voltage amplifier, and because this input offset voltage does not change much with time and temperature, these techniques are also called "zero-drift" amplifiers (because there is no drift in input offset voltage with time and temperature). Related techniques that also give these zero-drift advantages are auto-zero and chopper-stabilized amplifiers.


title: Chopper (electronics)

text: Auto-zero amplifiers use a secondary auxiliary amplifier to correct the input offset voltage of a main amplifier. Chopper-stabilized amplifiers use a combination of auto-zero and chopper techniques to give some excellent DC precision specifications.


title: Chopper (electronics)

text: Take a general step-up chopper with voltage source formula_2 which is in series with the inductor formula_3, diode and the load with average voltage formula_4. The chopper switch would be in parallel with the series diode and load. Whenever the chopper switch is on, the output is shorted. Using Kirchhoff Voltage Law in determining inductor voltage,


title: Chopper (electronics)

text: where formula_7is the time were a load voltage is present and formula_8 the change current with respect to formula_7. Whenever the chopper switch is off and using Kirchhoff Voltage Law in determining inductor voltage with respect to average current within the turn-on time,


title: Chopper (electronics)

text: where formula_11is the time were a load voltage is zero. Equating both average current and taking the duty cycle formula_12,


title: Chopper (electronics)

text: Taking a general step-down chopper with voltage source formula_2 which is in series with the chopper switch, inductor, and the load with voltage formula_15. The diode would be in parallel with the series inductor and load. The same way by equating the average inductor current during the turn-on and turn-off time, we can get the average voltage by


title: Chopper (electronics)

text: where formula_4is the average output voltage, formula_17is the duty cycle and formula_2is the source voltage.


title: Chopper (electronics)

text: Taking a general buck-boost chopper which works as stepup and down chopper, let the voltage source formula_2 be in series with the chopper switch, reverse biased diode, and the load with voltage formula_15. The inductor would be in parallel with the series diode and load. The same way by equating the average inductor current during the turn-on and turn-off time, we can get the average voltage by


title: Chopper (electronics)

text: where formula_4 is the average output voltage, formula_17is the duty cycle and formula_2is the source voltage.


title: Cement board

text: A cement board is a combination of cement and reinforcing fibers formed into sheets, of varying thickness that are typically used as a tile backing board. Cement board can be nailed or screwed to wood or steel studs to create a substrate for vertical tile and attached horizontally to plywood for tile floors, kitchen counters and backsplashes. It can be used on the exterior of buildings as a base for exterior plaster (stucco) systems and sometimes as the finish system itself.


title: Cement board

text: Cement board adds impact resistance and strength to the wall surface as compared to water resistant gypsum boards. Cement board is also fabricated in thin sheets with polymer modified cements to allow bending for curved surfaces.


title: Cement board

text: Cement bonded particle boards have treated wood flakes as reinforcement, whereas in cement fibre boards have cellulose fibre, which is a plant extract as reinforcement. Cement acts as binder in both the cases. The fire resistance properties of cement bonded blue particle boards and cement fibre boards are the same. In terms of load-bearing capacity, cement-bonded particle boards have higher capacity than cement fibre boards. Cement particle boards are manufactured from thickness making it suitable for high load bearing applications.


title: Cement board

text: These boards are made of a homogeneous mixture and hence are formed as single layer for any thickness. Cement fibre boards are more used in decorative applications and can be manufactured from thickness. Fibre boards are made in very thin layers, making it extremely difficult to manufacture high thickness boards. Many manufacturers use additives like mica, aluminium stearate and cenospheres in order to achieve certain board qualities. Typical cement fiber board is made of approximately 40-60% of cement, 20-30% of fillers, 8-10% of cellulose, 10-15% of mica. Other additives like above mentioned aluminium stearate and PVA are normally used in quantities less than 1%. Cenospheres are used only in low density boards with quantities between 10 and 15%. The actual recipe depends on available raw materials and other local factors.


title: Cement board

text: As a tile backing board, cement board has better long-term performance than paper-faced gypsum core products because it will not mildew or physically break down in the continued presence of moisture or leaks. Also cement board provides a stronger bond and support with tiles than typical gypsum board. Cement board is not waterproof. It absorbs moisture as well, but it has excellent drying properties. In areas continually exposed to water spray (i.e., showers) a waterproofing material is usually recommended behind the boards (i.e., plastic barrier) or as a trowel-applied product to the face of the boards behind the finish system (i.e., liquid membrane).


title: Cement board

text: One major disadvantage of cement board is the weight per square foot. It is approximately twice that of gypsum board, making handling by one person difficult. Cutting of cement board must also be done with carbide-tipped tools and saw blades. Due to its hardness, pre-drilling of fasteners is often recommended. Finally, cement board is initially more expensive than water resistant gypsum board but may provide better long term value.


title: Cement board

text: Cement board is hung with corrosion resistant screws or ring-shank nails. Cement board has very little movement under thermal stress, but the boards are usually installed with a slight gap at joints in shower pans, bathtubs, and each other. These joints are then filled with silicone sealant or the manufacturer's taping compounds before applying a finish. The filled joints are taped like conventional gypsum board, but with fiberglass tapes that provide additional water resistance. Combined with a water impermeable finish, cement board is a stable, durable backing board.


title: Cement board

text: There is a class of cement board strictly constructed of a Portland cement based core with glass fiber mat reinforcing at both faces. These panels can be immersed in water without any degradation (excluding freeze thaw cycles). These panels do not require the sealing of edges and penetrations to maintain their structural integrity. These Portland cement based products are smaller in size compared with the gypsum core based products. Typically they range in size from to . They are, as one would expect, considerably heavier than the gypsum core type panels.


title: Cement board

text: Portland cement based panels are ideal for truly wet locations like shower surrounds and for locations where a Portland cement based thin-set material is used for bonding tile and stone surfaces to a substrate. They are also ideal for floor tile and stone installations over a structural subfloor.


title: Cement board

text: Cement boards may be classified as water resistant as they are not affected by water exposure; however, they do allow penetration and passage of water and water vapor. To waterproof cement boards, a liquid or membrane waterproofing material is applied over its surface.


title: Cement board

text: Cement boards should not be confused with gypsum core backer boards. Gypsum core backer boards are affected by water and should not be used on wet exposure areas.


title: Long black

text: A long black is a style of coffee commonly found in Australia and New Zealand. It is similar to an Americano, but with a stronger aroma and taste.


title: Long black

text: A long black is made by pouring a double-shot of espresso or ristretto over hot water. Typically about 100–120 milliliters (3.5–4 ounces) of water is used but the measurement is considered to be flexible to individual taste. The smaller volume of water compared to an Americano is responsible for its stronger taste. Both retain the crema when brewed properly, though in the long black the crema will be more pronounced.


title: Hunarbaaz: Desh Ki Shaan

text: Hunarbaaz: Desh Ki Shaan is an Indian Hindi-language reality television show. Produced by Frames Production, the first episode of "Hunarbaaz: Desh Ki Shaan" premiered on 22 January 2022. Mithun Chakraborty, Parineeti Chopra and Karan Johar as the judges and Bharti Singh (Replaced By Surbhi Chandna) & Haarsh Limbachiyaa as the hosts. The First Season was won by Akash Singh.


title: Hunarbaaz: Desh Ki Shaan

text: "Hunarbaaz: Desh Ki Shaan" follows the format, in which contestants audition in front of three judges and a studio audience. Up until the semifinal and final rounds, the judges decide whether or not a contestant advances in the competition. During the semifinal and final rounds, viewers vote on which contestants will advance.


title: Hunarbaaz: Desh Ki Shaan

text: In contrast to other competition TV shows which feature a cast of celebrity judges, "Hunarbaaz" features a cast of celebrity experts and considers the viewers the judges. During each performance, the live studio audience is able to decide whether or not a contestant is sent through to the next round by using a voting panels.


title: Hunarbaaz: Desh Ki Shaan

text: While the live studio audience are considered the "judges", the judging panelists also may influence the vote with 10% of the voting power each.


title: Hunarbaaz: Desh Ki Shaan

text: The auditions are the first round where the acts are individually called to perform. With the start of the performance, voters have the option of voting just yes or no. If an expert votes yes, another 10% is added to the tally of the contestant.


title: Hunarbaaz: Desh Ki Shaan

text: Once the contestant reaches 80% of yes votes, the contestant goes to the next round of the competition.


title: Hunarbaaz: Desh Ki Shaan

text: This week's Judges' Votes was just an appreciation for the performances. And there was no elimination.


title: Hunarbaaz: Desh Ki Shaan

text: Parineeti Chopra was absent for this week. At the end of all performances, the judges decided to be eliminated two acts.


title: Hunarbaaz: Desh Ki Shaan

text: From this week onwards, the public votes were opened. And based on the public votes & judges scores, one act will be eliminated next week.


title: Hunarbaaz: Desh Ki Shaan

text: Based on the public votes & judges scores, two acts was eliminated and the season got the Top 7 acts.


title: Netaji Subhas University of Technology

text: Netaji Subhas University of Technology (NSUT), formerly Netaji Subhas Institute of Technology (NSIT) is a state university located in Dwarka, Delhi, India. In 2018, the institute was granted University status, changing its name to Netaji Subhas University of Technology (NSUT).


title: Netaji Subhas University of Technology

text: NSUT has a fully residential campus on 145 acres of land. Campus facilities include faculty and staff residences, student hostels, cooperative mess and a sports complex. The campus is divided into clusters of buildings. The administrative block contains important offices, banks, a post office, and an auditorium where major functions are held. The campus has four boys' hostels (one for each year) and two girls' hostels.


title: Netaji Subhas University of Technology

text: The Netaji Subhas University of Technology was ranked 22 in "The Week"-Hansa Research "Best Colleges Survey 2019: Top Engineering Colleges - All India".


title: History of biology

text: The history of biology traces the study of the living world from ancient to modern times. Although the concept of "biology" as a single coherent field arose in the 19th century, the biological sciences emerged from traditions of medicine and natural history reaching back to Ayurveda, ancient Egyptian medicine and the works of Aristotle and Galen in the ancient Greco-Roman world. This ancient work was further developed in the Middle Ages by Muslim physicians and scholars such as Avicenna. During the European Renaissance and early modern period, biological thought was revolutionized in Europe by a renewed interest in empiricism and the discovery of many novel organisms. Prominent in this movement were Vesalius and Harvey, who used experimentation and careful observation in physiology, and naturalists such as Linnaeus and Buffon who began to classify the diversity of life and the fossil record, as well as the development and behavior of organisms. Antonie van Leeuwenhoek revealed by means of microscopy the previously unknown world of microorganisms, laying the groundwork for cell theory. The growing importance of natural theology, partly a response to the rise of mechanical philosophy, encouraged the growth of natural history (although it entrenched the argument from design).


title: History of biology

text: Over the 18th and 19th centuries, biological sciences such as botany and zoology became increasingly professional scientific disciplines. Lavoisier and other physical scientists began to connect the animate and inanimate worlds through physics and chemistry. Explorer-naturalists such as Alexander von Humboldt investigated the interaction between organisms and their environment, and the ways this relationship depends on geography—laying the foundations for biogeography, ecology and ethology. Naturalists began to reject essentialism and consider the importance of extinction and the mutability of species. Cell theory provided a new perspective on the fundamental basis of life. These developments, as well as the results from embryology and paleontology, were synthesized in Charles Darwin's theory of evolution by natural selection. The end of the 19th century saw the fall of spontaneous generation and the rise of the germ theory of disease, though the mechanism of inheritance remained a mystery.


title: History of biology

text: In the early 20th century, the rediscovery of Mendel's work led to the rapid development of genetics by Thomas Hunt Morgan and his students, and by the 1930s the combination of population genetics and natural selection in the "neo-Darwinian synthesis". New disciplines developed rapidly, especially after Watson and Crick proposed the structure of DNA. Following the establishment of the Central Dogma and the cracking of the genetic code, biology was largely split between "organismal biology"—the fields that deal with whole organisms and groups of organisms—and the fields related to "cellular and molecular biology". By the late 20th century, new fields like genomics and proteomics were reversing this trend, with organismal biologists using molecular techniques, and molecular and cell biologists investigating the interplay between genes and the environment, as well as the genetics of natural populations of organisms.


title: History of biology

text: The earliest humans must have had and passed on knowledge about plants and animals to increase their chances of survival. This may have included knowledge of human and animal anatomy and aspects of animal behavior (such as migration patterns). However, the first major turning point in biological knowledge came with the Neolithic Revolution about 10,000 years ago. Humans first domesticated plants for farming, then livestock animals to accompany the resulting sedentary societies.


title: History of biology

text: In around 3000 to 1200 BCE, the Ancient Egyptians and Mesopotamians made contributions to astronomy, mathematics, and medicine, which later entered and shaped Greek natural philosophy of classical antiquity, a period that profoundly influenced the development of what came to be known as biology.


title: History of biology

text: Over a dozen medical papyri have been preserved, most notably the Edwin Smith Papyrus (the oldest extant surgical handbook) and the Ebers Papyrus (a handbook of preparing and using materia medica for various diseases), both from around 1600 BCE.


title: History of biology

text: Ancient Egypt is also known for developing embalming, which was used for mummification, in order to preserve human remains and forestall decomposition.


title: History of biology

text: The Mesopotamians seem to have had little interest in the natural world as such, preferring to study how the gods had ordered the universe. Animal physiology was studied for divination, including especially the anatomy of the liver, seen as an important organ in haruspicy. Animal behavior too was studied for divinatory purposes. Most information about the training and domestication of animals was probably transmitted orally, but one text dealing with the training of horses has survived.


title: History of biology

text: The ancient Mesopotamians had no distinction between "rational science" and magic. When a person became ill, doctors prescribed both magical formulas to be recited and medicinal treatments. The earliest medical prescriptions appear in Sumerian during the Third Dynasty of Ur ( 2112 – 2004 BCE). The most extensive Babylonian medical text, however, is the "Diagnostic Handbook" written by the "ummânū", or chief scholar, Esagil-kin-apli of Borsippa, during the reign of the Babylonian king Adad-apla-iddina (1069 – 1046 BCE). In East Semitic cultures, the main medicinal authority was an exorcist-healer known as an "āšipu". The profession was passed down from father to son and was held in high regard. Of less frequent recourse was the "asu", a healer who treated physical symptoms using remedies composed of herbs, animal products, and minerals, as well as potions, enemas, and ointments or poultices. These physicians, who could be either male or female, also dressed wounds, set limbs, and performed simple surgeries. The ancient Mesopotamians also practiced prophylaxis and took measures to prevent the spread of disease.


title: History of biology

text: Observations and theories regarding nature and human health, separate from Western traditions, had emerged independently in other civilizations such as those in China and the Indian subcontinent. In ancient China, earlier conceptions can be found dispersed across several different disciplines, including the work of herbologists, physicians, alchemists, and philosophers. The Taoist tradition of Chinese alchemy, for example, emphasized health (with the ultimate goal being the elixir of life). The system of classical Chinese medicine usually revolved around the theory of yin and yang, and the five phases. Taoist philosophers, such as Zhuangzi in the 4th century BCE, also expressed ideas related to evolution, such as denying the fixity of biological species and speculating that species had developed differing attributes in response to differing environments.


title: History of biology

text: One of the oldest organised systems of medicine is known from ancient India in the form of Ayurveda, which originated around 1500 BCE from Atharvaveda (one of the four most ancient books of Indian knowledge, wisdom and culture).


title: History of biology

text: The ancient Indian Ayurveda tradition independently developed the concept of three humours, resembling that of the four humours of ancient Greek medicine, though the Ayurvedic system included further complications, such as the body being composed of five elements and seven basic tissues. Ayurvedic writers also classified living things into four categories based on the method of birth (from the womb, eggs, heat & moisture, and seeds) and explained the conception of a fetus in detail. They also made considerable advances in the field of surgery, often without the use of human dissection or animal vivisection. One of the earliest Ayurvedic treatises was the "Sushruta Samhita", attributed to Sushruta in the 6th century BCE. It was also an early materia medica, describing 700 medicinal plants, 64 preparations from mineral sources, and 57 preparations based on animal sources.


title: History of biology

text: The pre-Socratic philosophers asked many questions about life but produced little systematic knowledge of specifically biological interest—though the attempts of the atomists to explain life in purely physical terms would recur periodically through the history of biology. However, the medical theories of Hippocrates and his followers, especially humorism, had a lasting impact.


title: History of biology

text: The philosopher Aristotle was the most influential scholar of the living world from classical antiquity. Though his early work in natural philosophy was speculative, Aristotle's later biological writings were more empirical, focusing on biological causation and the diversity of life. He made countless observations of nature, especially the habits and attributes of plants and animals in the world around him, which he devoted considerable attention to categorizing. In all, Aristotle classified 540 animal species, and dissected at least 50. He believed that intellectual purposes, formal causes, guided all natural processes.


title: History of biology

text: Aristotle, and nearly all Western scholars after him until the 18th century, believed that creatures were arranged in a graded scale of perfection rising from plants on up to humans: the "scala naturae" or Great Chain of Being. Aristotle's successor at the Lyceum, Theophrastus, wrote a series of books on botany—the "History of Plants"—which survived as the most important contribution of antiquity to botany, even into the Middle Ages. Many of Theophrastus' names survive into modern times, such as "carpos" for fruit, and "pericarpion" for seed vessel. Dioscorides wrote a pioneering and encyclopaedic pharmacopoeia, "De Materia Medica", incorporating descriptions of some 600 plants and their uses in medicine. Pliny the Elder, in his "Natural History", assembled a similarly encyclopaedic account of things in nature, including accounts of many plants and animals.


title: History of biology

text: A few scholars in the Hellenistic period under the Ptolemies—particularly Herophilus of Chalcedon and Erasistratus of Chios—amended Aristotle's physiological work, even performing dissections and vivisections. Claudius Galen became the most important authority on medicine and anatomy. Though a few ancient atomists such as Lucretius challenged the teleological Aristotelian viewpoint that all aspects of life are the result of design or purpose, teleology (and after the rise of Christianity, natural theology) would remain central to biological thought essentially until the 18th and 19th centuries. Ernst W. Mayr argued that "Nothing of any real consequence happened in biology after Lucretius and Galen until the Renaissance." The ideas of the Greek traditions of natural history and medicine survived, but they were generally taken unquestioningly in medieval Europe.


title: History of biology

text: The decline of the Roman Empire led to the disappearance or destruction of much knowledge, though physicians still incorporated many aspects of the Greek tradition into training and practice. In Byzantium and the Islamic world, many of the Greek works were translated into Arabic and many of the works of Aristotle were preserved.


title: History of biology

text: During the High Middle Ages, a few European scholars such as Hildegard of Bingen, Albertus Magnus and Frederick II wrote on natural history. The rise of European universities, though important for the development of physics and philosophy, had little impact on biological scholarship.


title: History of biology

text: The European Renaissance brought expanded interest in both empirical natural history and physiology. In 1543, Andreas Vesalius inaugurated the modern era of Western medicine with his seminal human anatomy treatise "De humani corporis fabrica", which was based on dissection of corpses. Vesalius was the first in a series of anatomists who gradually replaced scholasticism with empiricism in physiology and medicine, relying on first-hand experience rather than authority and abstract reasoning. Via herbalism, medicine was also indirectly the source of renewed empiricism in the study of plants. Otto Brunfels, Hieronymus Bock and Leonhart Fuchs wrote extensively on wild plants, the beginning of a nature-based approach to the full range of plant life. Bestiaries—a genre that combines both the natural and figurative knowledge of animals—also became more sophisticated, especially with the work of William Turner, Pierre Belon, Guillaume Rondelet, Conrad Gessner, and Ulisse Aldrovandi.


title: History of biology

text: Artists such as Albrecht Dürer and Leonardo da Vinci, often working with naturalists, were also interested in the bodies of animals and humans, studying physiology in detail and contributing to the growth of anatomical knowledge. The traditions of alchemy and natural magic, especially in the work of Paracelsus, also laid claim to knowledge of the living world. Alchemists subjected organic matter to chemical analysis and experimented liberally with both biological and mineral pharmacology. This was part of a larger transition in world views (the rise of the mechanical philosophy) that continued into the 17th century, as the traditional metaphor of "nature as organism" was replaced by the "nature as machine" metaphor.


title: History of biology

text: Systematizing, naming and classifying dominated natural history throughout much of the 17th and 18th centuries. Carl Linnaeus published a basic taxonomy for the natural world in 1735 (variations of which have been in use ever since), and in the 1750s introduced scientific names for all his species. While Linnaeus conceived of species as unchanging parts of a designed hierarchy, the other great naturalist of the 18th century, Georges-Louis Leclerc, Comte de Buffon, treated species as artificial categories and living forms as malleable—even suggesting the possibility of common descent. Though he was opposed to evolution, Buffon is a key figure in the history of evolutionary thought; his work would influence the evolutionary theories of both Lamarck and Darwin.


title: History of biology

text: The discovery and description of new species and the collection of specimens became a passion of scientific gentlemen and a lucrative enterprise for entrepreneurs; many naturalists traveled the globe in search of scientific knowledge and adventure.


title: History of biology

text: Extending the work of Vesalius into experiments on still living bodies (of both humans and animals), William Harvey and other natural philosophers investigated the roles of blood, veins and arteries. Harvey's "De motu cordis" in 1628 was the beginning of the end for Galenic theory, and alongside Santorio Santorio's studies of metabolism, it served as an influential model of quantitative approaches to physiology.


title: History of biology

text: In the early 17th century, the micro-world of biology was just beginning to open up. A few lensmakers and natural philosophers had been creating crude microscopes since the late 16th century, and Robert Hooke published the seminal "Micrographia" based on observations with his own compound microscope in 1665. But it was not until Antonie van Leeuwenhoek's dramatic improvements in lensmaking beginning in the 1670s—ultimately producing up to 200-fold magnification with a single lens—that scholars discovered spermatozoa, bacteria, infusoria and the sheer strangeness and diversity of microscopic life. Similar investigations by Jan Swammerdam led to a new interest in entomology and built the basic techniques of microscopic dissection and staining.


title: History of biology

text: As the microscopic world was expanding, the macroscopic world was shrinking. Botanists such as John Ray worked to incorporate the flood of newly discovered organisms shipped from across the globe into a coherent taxonomy, and a coherent theology (natural theology). Debate over another flood, the Noachian, catalyzed the development of paleontology; in 1669 Nicholas Steno published an essay on how the remains of living organisms could be trapped in layers of sediment and mineralized to produce fossils. Although Steno's ideas about fossilization were well known and much debated among natural philosophers, an organic origin for all fossils would not be accepted by all naturalists until the end of the 18th century due to philosophical and theological debate about issues such as the age of the earth and extinction.


title: History of biology

text: Up through the 19th century, the scope of biology was largely divided between medicine, which investigated questions of form and function (i.e., physiology), and natural history, which was concerned with the diversity of life and interactions among different forms of life and between life and non-life. By 1900, much of these domains overlapped, while natural history (and its counterpart natural philosophy) had largely given way to more specialized scientific disciplines—cytology, bacteriology, morphology, embryology, geography, and geology.


title: History of biology

text: The term "biology" in its modern sense appears to have been introduced independently by Thomas Beddoes (in 1799), Karl Friedrich Burdach (in 1800), Gottfried Reinhold Treviranus ("Biologie oder Philosophie der lebenden Natur", 1802) and Jean-Baptiste Lamarck ("Hydrogéologie", 1802). The word itself appears in the title of Volume 3 of Michael Christoph Hanow's "Philosophiae naturalis sive physicae dogmaticae: Geologia, biologia, phytologia generalis et dendrologia", published in 1766.


title: History of biology

text: Before "biology," there were several terms used for the study of animals and plants. "Natural history" referred to the descriptive aspects of biology, though it also included mineralogy and other non-biological fields; from the Middle Ages through the Renaissance, the unifying framework of natural history was the "scala naturae" or Great Chain of Being. "Natural philosophy" and "natural theology" encompassed the conceptual and metaphysical basis of plant and animal life, dealing with problems of why organisms exist and behave the way they do, though these subjects also included what is now geology, physics, chemistry, and astronomy. Physiology and (botanical) pharmacology were the province of medicine. "Botany", "Zoology", and (in the case of fossils) "Geology" replaced "natural history" and "natural philosophy" in the 18th and 19th centuries before "biology" was widely adopted. To this day, "botany" and "zoology" are widely used, although they have been joined by other sub-disciplines of biology.


title: History of biology

text: Widespread travel by naturalists in the early-to-mid-19th century resulted in a wealth of new information about the diversity and distribution of living organisms. Of particular importance was the work of Alexander von Humboldt, which analyzed the relationship between organisms and their environment (i.e., the domain of natural history) using the quantitative approaches of natural philosophy (i.e., physics and chemistry). Humboldt's work laid the foundations of biogeography and inspired several generations of scientists.


title: History of biology

text: The emerging discipline of geology also brought natural history and natural philosophy closer together; the establishment of the stratigraphic column linked the spatial distribution of organisms to their temporal distribution, a key precursor to concepts of evolution. Georges Cuvier and others made great strides in comparative anatomy and paleontology in the late 1790s and early 19th century. In a series of lectures and papers that made detailed comparisons between living mammals and fossil remains Cuvier was able to establish that the fossils were remains of species that had become extinct—rather than being remains of species still alive elsewhere in the world, as had been widely believed. Fossils discovered and described by Gideon Mantell, William Buckland, Mary Anning, and Richard Owen among others helped establish that there had been an 'age of reptiles' that had preceded even the prehistoric mammals. These discoveries captured the public imagination and focused attention on the history of life on earth. Most of these geologists held to catastrophism, but Charles Lyell's influential "Principles of Geology" (1830) popularised Hutton's uniformitarianism, a theory that explained the geological past and present on equal terms.


title: History of biology

text: The most significant evolutionary theory before Darwin's was that of Jean-Baptiste Lamarck; based on the inheritance of acquired characteristics (an inheritance mechanism that was widely accepted until the 20th century), it described a chain of development stretching from the lowliest microbe to humans. The British naturalist Charles Darwin, combining the biogeographical approach of Humboldt, the uniformitarian geology of Lyell, Thomas Malthus's writings on population growth, and his own morphological expertise, created a more successful evolutionary theory based on natural selection; similar evidence led Alfred Russel Wallace to independently reach the same conclusions.


title: History of biology

text: The 1859 publication of Darwin's theory in "On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life" is often considered the central event in the history of modern biology. Darwin's established credibility as a naturalist, the sober tone of the work, and most of all the sheer strength and volume of evidence presented, allowed "Origin" to succeed where previous evolutionary works such as the anonymous "Vestiges of Creation" had failed. Most scientists were convinced of evolution and common descent by the end of the 19th century. However, natural selection would not be accepted as the primary mechanism of evolution until well into the 20th century, as most contemporary theories of heredity seemed incompatible with the inheritance of random variation.


title: History of biology

text: Wallace, following on earlier work by de Candolle, Humboldt and Darwin, made major contributions to zoogeography. Because of his interest in the transmutation hypothesis, he paid particular attention to the geographical distribution of closely allied species during his field work first in South America and then in the Malay archipelago. While in the archipelago he identified the Wallace line, which runs through the Spice Islands dividing the fauna of the archipelago between an Asian zone and a New Guinea/Australian zone. His key question, as to why the fauna of islands with such similar climates should be so different, could only be answered by considering their origin. In 1876 he wrote "The Geographical Distribution of Animals", which was the standard reference work for over half a century, and a sequel, "Island Life", in 1880 that focused on island biogeography. He extended the six-zone system developed by Philip Sclater for describing the geographical distribution of birds to animals of all kinds. His method of tabulating data on animal groups in geographic zones highlighted the discontinuities; and his appreciation of evolution allowed him to propose rational explanations, which had not been done before.


title: History of biology

text: The scientific study of heredity grew rapidly in the wake of Darwin's "Origin of Species" with the work of Francis Galton and the biometricians. The origin of genetics is usually traced to the 1866 work of the monk Gregor Mendel, who would later be credited with the laws of inheritance. However, his work was not recognized as significant until 35 years afterward. In the meantime, a variety of theories of inheritance (based on pangenesis, orthogenesis, or other mechanisms) were debated and investigated vigorously. Embryology and ecology also became central biological fields, especially as linked to evolution and popularized in the work of Ernst Haeckel. Most of the 19th century work on heredity, however, was not in the realm of natural history, but that of experimental physiology.


title: History of biology

text: Over the course of the 19th century, the scope of physiology expanded greatly, from a primarily medically oriented field to a wide-ranging investigation of the physical and chemical processes of life—including plants, animals, and even microorganisms in addition to man. "Living things as machines" became a dominant metaphor in biological (and social) thinking.


title: History of biology

text: Advances in microscopy also had a profound impact on biological thinking. In the early 19th century, a number of biologists pointed to the central importance of the cell. In 1838 and 1839, Schleiden and Schwann began promoting the ideas that (1) the basic unit of organisms is the cell and (2) that individual cells have all the characteristics of life, though they opposed the idea that (3) all cells come from the division of other cells. Thanks to the work of Robert Remak and Rudolf Virchow, however, by the 1860s most biologists accepted all three tenets of what came to be known as cell theory.


title: History of biology

text: Cell theory led biologists to re-envision individual organisms as interdependent assemblages of individual cells. Scientists in the rising field of cytology, armed with increasingly powerful microscopes and new staining methods, soon found that even single cells were far more complex than the homogeneous fluid-filled chambers described by earlier microscopists. Robert Brown had described the nucleus in 1831, and by the end of the 19th century cytologists identified many of the key cell components: chromosomes, centrosomes mitochondria, chloroplasts, and other structures made visible through staining. Between 1874 and 1884 Walther Flemming described the discrete stages of mitosis, showing that they were not artifacts of staining but occurred in living cells, and moreover, that chromosomes doubled in number just before the cell divided and a daughter cell was produced. Much of the research on cell reproduction came together in August Weismann's theory of heredity: he identified the nucleus (in particular chromosomes) as the hereditary material, proposed the distinction between somatic cells and germ cells (arguing that chromosome number must be halved for germ cells, a precursor to the concept of meiosis), and adopted Hugo de Vries's theory of pangenes. Weismannism was extremely influential, especially in the new field of experimental embryology.


title: History of biology

text: By the mid-1850s the miasma theory of disease was largely superseded by the germ theory of disease, creating extensive interest in microorganisms and their interactions with other forms of life. By the 1880s, bacteriology was becoming a coherent discipline, especially through the work of Robert Koch, who introduced methods for growing pure cultures on agar gels containing specific nutrients in Petri dishes. The long-held idea that living organisms could easily originate from nonliving matter (spontaneous generation) was attacked in a series of experiments carried out by Louis Pasteur, while debates over vitalism vs. mechanism (a perennial issue since the time of Aristotle and the Greek atomists) continued apace.