Daily Archives: January 5, 2017

Mythology of Stargate – Wikipedia

Posted: January 5, 2017 at 11:10 am

In the fictional universe of the Stargate franchise, the people of Earth have encountered numerous extraterrestrial races on their travels through the Stargate. In addition to a diversity of alien life, there is also an abundance of other humans, scattered across the cosmos by advanced aliens in the distant past. Some of the most significant species in Stargate SG-1 are the Goa'uld, the Asgard, and the Replicators. Stargate Atlantis, set in the Pegasus galaxy, introduced the Wraith and the Asurans. One of the most influential species in Stargate, the Ancients, have moved on to a higher plane of existence. For practical reasons of television productions, almost all of the alien and human cultures in the Stargate's fictional universe speak native English. Because of the time constraints of an hour-long episode, it would become a major hindrance to the story each week if the team had to spend a sizeable part of each episode learning to communicate with a new species.[1]

Stargate SG-1 explains the human population in the Milky Way galaxy by revealing that the alien Goa'uld transplanted humans from Earth to other planets for slave labor. Many of these populations were subsequently abandoned, often when deposits of the precious fictional mineral naqahdah were exhausted, and developed into their own unique societies.[2] Some of these extraterrestrial human civilizations have become much more technologically advanced than Earth, the in-show rationale being that they never suffered the setback of the Dark Ages. The most advanced of these humans were the Tollan, although they were destroyed by the Goa'uld in Season 5's Between Two Fires.[3] The human populations of the Pegasus galaxy are the product of Ancient seeding.[4] few human races in Pegasus are technologically advanced, as the Wraith destroy any civilization that could potentially pose a threat.[5] There are also large numbers of humans in the Ori galaxy, where they empower the Ori through worship.[6]

Stargate SG-1 takes place mostly in the Milky Way galaxy. Brad Wright and Jonathan Glassner tried to stay true to the feature film, but also wanted Stargate SG-1 to be unique in its own way.[7]Stargate SG-1 gradually evolved away from the basic premise of the film and developed its own unique mythological superstructure.[8]Stargate SG-1 elaborated on the film's Egyptian hybrid mythology and mixed in other historical mythologies, coming up with a mythological superstructure that explains the existence of all of the other mythologies in the overarching Stargate narrative.[9] The series expands upon Egyptian mythology (notably the Egyptian gods Apep/Apophis, and Anubis as Goa'uld villains), Norse mythology (notably the god Thor as an Asgard ally), Arthurian legend (notably Merlin as an Ancient ally), and many other mythologies like Greek and Roman mythology. SG-1 does not introduce new alien races as often as some other science fiction television series.[10] Most civilizations that the Goa'uld had transplanted maintain much of their original Earth culture, and Stargate SG-1 does not equate civilization with technology like many other sci-fi shows do.[11] Newly encountered races or visited planets are integrated into the mythology, although plotlines of individual episodes are often new, self-standing and accessible for new audiences, giving a compelling internal coherence.[12]

Stargate Atlantis is set in the Pegasus Galaxy and explores the adventures of an "elite expedition" from Earth. The gate address to the legendary city Atlantis is discovered on Earth by Daniel Jackson at the end of 7th season/start of the 8th season of Stargate SG-1. The Earth expedition has a multi-nation civilian leadership and a predominantly United States military faction providing security. The intent of establishing a diplomatic mission with inhabitants of the galaxy and a permanent human base in the city of Atlantis for scientific and military research and exploration are driving goals for the humans.[13]

Stargate Universe was conceived as "a completely separate, third entity" in the live-action Stargate franchise.[14] Although it is firmly entrenched in pre-established Stargate mythology, Stargate Universe has diverged in a new direction.[15] Like the first two series in the franchise, Stargate Universe takes place during the present time, not in the distant future.[14]

The show is set on the Ancient ship Destiny. Destiny was part of an Ancient experiment to seed the universe with Stargates millions of years ago but which was lost because of the Ancients' ascension. Ships were sent ahead of the Destiny to seed the universe with Stargates. The Destiny itself was intended to follow a pre-programmed course to explore these galaxies; the Destiny was left unmanned at the time of the Ancients' ascension. To reach this ship, an address would have to be dialled consisting of nine chevrons. The destination of this ninth chevron was previously unknown.[16] The series starts when a team of soldiers and scientists from Earth step through the Stargate to find the Destiny[17] after their base is attacked; unable to return to Earth, they must fend for themselves aboard the ship as it takes them to the far reaches of the universe.[18][19][20] The show was more serialized than its predecessors.[21]

The show is more relationship-based and more arc-driven[22] and will involve more space-based action than SG-1 or Atlantis.[18] "Survival and sacrifice" were the two main themes that were discussed at the preliminary script stages of the show,[23] and the first episode deals with a failing life support system.[24]Stargate Universe will be "a lot darker" than the previous Stargate series,[25] although humor will remain part of the franchise.[26] The show focuses mostly on the people aboard the ship instead of planet-based exploration,[22] and in Brad Wright's words will be "hopefully exploring the truly alien, and avoiding the rubber faced English-speaking one".[26] Despite the focus on survival, the show "will also focus on exploration and adventure and, by extension, the occasional alien encounter as well".[27] A single dominant villain race like on SG-1 and Atlantis are not featured.[26]

A Stargate is a fictional device that allows practical, rapid travel between two distant locations. The first Stargate appears in the 1994 film Stargate, and subsequently carries over to Stargate SG-1 and its spin-offs. In these productions the Stargate functions as a plot generator, allowing the main characters to visit alien planets without the need for spaceships or any other fictional technology.

Within the Stargate fictional universe, Stargates are large metal rings with nine "chevrons" spaced equally around their circumference. Pairs of Stargates function by generating an artificial stable wormhole between them, allowing one-way travel through. The symbols on the inner ring of the Stargate correspond to constellations and serve to map out coordinates for various destination planets.[2][28] A typical Stargate measures 6.7m (22ft) in diameter, weighs 29,000kg (64,000lb),[29] and is made of the fictional heavy mineral "naqahdah".[2] The Stargates were created millions of years ago by an alien race known as the Ancients;[30] their modern history begins when Egyptologist Daniel Jackson deciphers their workings in the Stargate film.[28]

The Stargate device sets apart SG-1 from other science fiction shows by allowing modern-day people to travel to other planets in an instant,[31] although scholar Dave Hipple argued that SG-1 "also deploys [science fiction] stereotypes both to acknowledge forebears and to position itself as a deserving heir".[32] With the help of the central Stargate device, the premise of Stargate SG-1 combines ancient cultures, present-day political and social concerns, aliens and advanced technologies.[8] Near-instantaneous interplanetary travel allows a fundamental difference in plot structure and set design from other series. There is a disjunction between politics on Earth and the realities of fighting an interstellar war.[33] The Stargate also helps to speed up the exposition of the setting.[12]

The Ancients are the original builders of the Stargate network. At the time of their introduction in SG-1's "Maternal Instinct" (season 3), they have long Ascended beyond corporeal form into a higher plane of existence. The humans of Earth are the "second evolution" of the Ancients. The Ancients (originally known as the Alterans) colonized the Milky Way galaxy millions of years ago and built a great empire. They also colonized the Pegasus galaxy and seeded human life there, before being driven out by the Wraith. The civilization of the Ancients in the Milky Way was decimated thousands of years ago by a plague, and those who did not learn to ascend died out. With few exceptions, the ascended Ancients respect free will and refuse to interfere in the affairs of the material galaxy. However, their legacy is felt profoundly throughout the Stargate universe, from their technologies (such as Stargates and Atlantis, to the Ancient Technology Activation gene, that they introduced into the human genome through interbreeding) as well as many of the antagonists in the series, having resulted from failures or negligence on the part of the Ancients.

The Ancients were a small percentage of the Alteran Population, the remainder focused more on religious pursuits than scientific ones. Upon ascending to their higher plane of existence, they discovered ways of gaining strength by convincing material humans to abandon their wills to the ascendants' desires. The Ori created the religion of Origin to gain power from the humans who practiced their religion. Priors, missionaries of the Origin religion, attempted to forcefully introduce their belief system to the Milky Way Galaxy. Their ways of conversion brought forth indiscriminate intimidation, terror and consequences. The people of Earth fought vehemently against this oppressive force and encouraged the people of the Milky Way Galaxy to defend their cultures and beliefs. The ascended Ancients did not become involved in the struggle and thereby allow the humans from Earth to maintain their role as heroic defenders.[10]

Aschen[34] are a technologically advanced (much more so than humans) race, from a world designated P4C-970. Aschen are a rather unemotional people (described as a "race of accountants"), and can't tolerate loud noises which humans normally can. Typically, the Aschen will approach a prospective world, invite them into the Aschen Confederation, and provide that world with advanced medicines and technology; however, the Aschen then secretly target that world with a variety of covert means (including biological weapons), intended to severely reduce that planet's population and thus create a new farming world to use for the Aschen's benefit. In the Episode 2001[35] it is mentioned that the Volian homeworld was such a target; the Volians were formerly a prosperous technological civilization but reduced to little more than a few scattered farming communities. The Aschen also have the ability to turn a Jovian-type planet into a second sun to increase crop yields, and also possess a form of teleportation.

A benevolent race that, according to the mythology of Stargate, gave rise to Norse mythology on Earth and inspired accounts of the Roswell Greys. The Asgard can no longer reproduce and therefore perpetuate themselves by transferring their minds into new clone bodies as necessary. Extremely advanced technologically, the threat of their intervention shields many planets in the Milky Way from Goa'uld attack, including Earth.[36] They also provide much assistance to Earth in the way of technology, equipment, and expertise. Their main adversary in Stargate SG-1 are the mechanical Replicators, against which they enlist the aid of SG-1 on several occasions. The entire Asgard civilization chooses to self-destruct in "Unending", due to the degenerative effects of repeated cloning. A small rogue colony of Asgard, known as the Vanir, still exist in the Pegasus galaxy. They were able to slow cloning's diminishing returns by experimenting on humans.

Artificial life-forms composed of nanites, introduced in season 3 of Stargate Atlantis. They are similar to the human-form Replicators of Stargate SG-1 and so are called that in the show. The Asurans were created by the Ancients to combat the Wraith but were ultimately abandoned for being too dangerous. Extremely aggressive, the nanites thrived and built an advanced civilization. In season 4, Rodney McKay activates the Asurans' attack code, causing them to attack the Wraith, but this eventually comes to threaten all the inhabitants of Pegasus as the Asurans decide the best strategy is to starve the Wraith by eliminating all human life in the galaxy.

A't'trr: Microscopic aliens that feed on energy.

Crystalline species: Beings that can travel through electrical conductors and can enter the minds of humans through touch.

The Berzerker drones are a robotic war system with attack drones and motherships to control them. They appear to attack and destroy all not-self spacecraft. The Destiny crew speculate that their parent civilization is long dead, and that they just carry out their mission to destroy all non-native technology, destroying other races along the way.[37]

These bugs give the illusion of sand floating around. They can consume large volumes of water at a rapid rate considering they are such small entities. They seem to be intelligent creatures and are passive and helpful unless provoked, in which case they can be extremely lethal. They fly around in "swarms" and will attack together. They were the first species to be encountered in the Destiny expedition, though they were initially dismissed as a hallucination suffered by Matthew Scott. The creatures appeared to develop a rapport with Scott and aided him in his quest for Lime after he offered them water as a test of their sentience. The creatures also revived him on their home world when he collapsed due to the heat, through burrowing into the ground to release some water to wake him.

Energy beings

The Furlings are revealed as one of the alliance of four great races in "The Fifth Race", but virtually nothing else has been revealed about them in the series. In "Paradise Lost", Harry Maybourne leads SG-1 to a Furling teleportation arch that leads to an intended Utopian colony. Furling skeletons were originally planned to be featured in the episode, but the production of such proved to be too expensive.[38]Jack O'Neill concludes that the Furlings must be cute and cuddly creatures, based solely on their name. In "Citizen Joe", another character equates the Furlings to Ewoks based on their name.

The length of time that the Furling nature has remained a mystery in the series has given the producers the opportunity to tease fans with a running gag. When Executive Producer Robert C. Cooper was asked "Will we ever meet the Furlings?", his answer was "Who says we haven't?".[39] The writers later went on to state that although we have seen Furling technology and the Furling legacy, no actual Furling has ever appeared on the show. Joseph Mallozzi claimed that more about the Furlings would finally be revealed in Stargate SG-1's tenth season.[40] In a Sci Fi Channel advertisement for the 200th episode, Cooper stated that "We're finally going to get to see the Furlings." What was actually shown was an imagined scene from a script for a movie based on the fictional television series "Wormhole X-Treme!", a parody of Stargate SG-1 set in the Stargate SG-1 universe. The Furlings were depicted as Ewok-like, or Koala-like creatures that are destroyed by the Goa'uld soon after making contact with SG-1.

Gadmeer The society of the Gadmeer was a peaceful and technologically advanced one that lasted for over 10,000 years. Over a thousand years ago they were defeated by a superior power due to a lack of military technology and tactics, and thus their race apparently died out. To prevent their culture from vanishing they built a giant vessel which stored all their knowledge, including arts, mathematics and even the DNA samples of thousands of the plants and animals of their homeworld. [41]

The Goa'uld are the dominant race in the Milky Way and the primary adversaries from seasons 1 to 8 of Stargate SG-1. They are a parasitic species that resemble finned snakes, which can burrow themselves into a humanoid's neck and wrap around the spinal column. The Goa'uld symbiote then takes control of its host's body and mind, while providing longevity and perfect health. Thousands of years ago, the Goa'uld ruled over Earth, masquerading as gods from ancient mythologies. They transplanted humans throughout the galaxy to serve as slaves and hosts, and they created the Jaffa to serve as incubators for their larvae. The most powerful Goa'uld in the galaxy are collectively known as the System Lords.

The Goa'uld are the first and most prominent alien race encountered by the SGC, and also one of the few nonhumanoid species to appear in the early seasons of the series. The Goa'uld are branded as evil by their pretending to be gods and forcing people to submit to their quasireligious pronouncements.[10]

The humans of Earth play a central role in the story and mythology of the Stargate fictional universe. According to the Stargate film and Stargate SG-1, the parasitic Goa'uld ruled Earth thousands of years ago, posing as gods of ancient Earth mythologies, and transplanted Earth humans throughout the galaxy via the Stargate. Thus, the Goa'uld and their Jaffa servants know the humans of Earth as the "Tau'ri" ( or ), which means "the first ones" or "those of the first world" in their fictional language.[2] Earth is also known as "Midgard" by offworld humans protected by the Asgard, who masquerade as Norse gods.[42][43]Stargate SG-1 further extended the backstory of Earth humans by introducing the Ancients, an advanced race of humans from another galaxy. The Ancients regard the humans of Earth as their "second evolution",[44] and some of their number merged with primitive human populations 10,000 years ago after they returned to Earth from Atlantis.[4]

Five thousand years ago, the people of Earth rose up against their Goa'uld oppressors, and buried their Stargate.[28] The modern history of Earth and the Stargate begins when it is unearthed in Egypt in 1928. The device is brought to the United States in 1939 to keep it out of Nazi hands and eventually installed in a facility in Creek Mountain, Colorado (Cheyenne Mountain in Stargate SG-1).[28] In the events of the Stargate film, Dr. Daniel Jackson deciphers the workings of the Stargate and a team is sent through to the planet on the other side. In "Children of the Gods", taking place a year after the film, Stargate Command is established in response to an attack by the Goa'uld Apophis, and given the mandate to explore other worlds and obtain technologies that can be used to defend Earth. In the Stargate SG-1 spin-off Stargate Atlantis, the people of Earth establish a presence in the Pegasus galaxy. The ancients who occupied Atlantis in the Pegasus galaxy are often referred to as the "Atlanteans" (or simply "Lanteans"), after their occupation of Atlantis.

The writers had to strike a balance in the interaction between the explorers from Earth and advanced races (of which there were only few in the story) so that alliances could be developed where the advanced races do not give Earth all their technology and knowledge.[45]Stargate SG-1 emphasized its present-day-Earth story frame by frequently referencing popular culture, like The X-Files and Buffy the Vampire Slayer had done before.[32] According to one critic in 1997, Stargate SG-1 was designed to have no nationality, which might appeal to viewers all over the world.[46] The final episodes of season 7 (2004) brought a more global approach to the scenario when the Stargate Program was revealed to over a dozen nations, which further helped the international appeal of Stargate SG-1.[47]

A new race created by the Wraith Michael, first seen in "Vengeance". After being outcast by his own kind, Michael sought to combine iratus bug and human DNA to create new followers with the strengths of the Wraith but not their weaknesses. He destroys the Taranians, amongst others, as test subjects for his experiments. The first Hybrids are bestial in appearance, with carapaces and claws. The two-part episode "The Kindred" reveals that Michael has created more "refined" Hybrids using the abducted Athosian population. These Hybrids resemble the Wraith, but do not need to feed on humans. In "Search and Rescue", many of the Hybrids are killed by the destruction of Michael's cruiser, and the rest are captured by the Atlantis Expedition. They are transformed back into their original selves using Beckett's retrovirus. They are interred in a camp on the mainland by the IOA,[48] before being allowed to return to their people.[49] In the episode "Whispers", an Atlantis team discovers one of Michael's labs, containing earlier versions of his Hybrids that incorporate DNA from several other organisms in addition to the iratus bug. These vicious creatures are blind and hunt by sound, and can extrude a fog from gill slits on their necks that interferes with electronics.

The Jaffa (usually pronounced jah'FAH) are modified humans genetically engineered by the Goa'uld in antiquity to serve as soldiers and as incubators for their young. Their story is primarily told through Teal'c. The main difference between a Jaffa and a normal human is an abdominal pouch accessible from the outside by a X-shaped slit.[2] The pouch serves as an incubator for a larval Goa'uld. Implanted during a "coming of age" rite known as a prim'tah, the pouch improves the Goa'uld's ability to successfully take a host upon maturation from 50% to nearly 100%. The Goa'uld have a device capable of quickly transforming humans into Jaffa.[50] The larval symbiote grants the Jaffa enhanced strength, health, healing, and longevity (more than 150 years). However, the presence of the symbiote also replaces the Jaffa's immune system, and if removed the Jaffa will die a slow and painful death that can only be avoided by either acquiring a new symbiote or by lifelong regular injections of the drug tretonin which replaces the Goa'uld functions in the Jaffa body.[51] The Jaffa equivalent of puberty is the Age of Prata, at which time a prim'tah must be performed.[52] Jaffa do not require sleep, but must engage in a form of meditation called kel'no'reem to synchronize with their symbiote.[53] It is possible for a Jaffa to communicate with his/her symbiote through a dangerously deep state of kel'no'reem.[54]

Jaffa who are in service of a Goa'uld bear a black tattoo of their master's insignia on their foreheads. The highest-ranking Jaffa in the service of a Goa'uld is known as the First Prime and bears a raised gold insignia, made by baring the bone with a special knife and filling the wound with molten gold; Teal'c describes it as a painful process. Other high-ranking Jaffa may bear similar silver marks. The elite guard of powerful Goa'uld sometimes wear helmets shaped like that Goa'uld's symbolic animal; the helmets are made from articulated metal plates that can fold to reveal the face, and are intended to intimidate the Goa'uld's enslaved human populations. Helmeted Jaffa seen or mentioned in the series include the Horus Guards (falcon-headed, serving Ra and Heru-ur),[28][55] Serpent Guards (cobra-headed, serving Apophis),[2] and the Setesh Guards (Set animal-headed, serving Seth).[56] A jackal-headed (Anubis) guard also appears in service of Ra in the Stargate movie.

SG-1 encounters three notable Jaffa factions. The Hak'tyl ("liberation"), introduced in "Birthright", are a group of female Jaffa warriors founded by Ishta, High Priestess of the Goa'uld Moloc. When Moloc ordered that all female children born to his Jaffa be sacrificed, Ishta began secretly saving them on the planet Hak'tyl. The SGC assassinates Moloc in "Sacrifices". The Hak'tyl are a significant power in the Free Jaffa Nation, and are represented by Ka'lel on the High Council.[57] The Sodan are introduced in "Babylon" as a legendary group of Jaffa who, over 5,000 years ago, realized that the Goa'uld were not gods and rebelled against their Goa'uld master Ishkur. The Sodan worship the Ancients and seek Ascension as their ultimate goal. They do not have tattoos on their foreheads specifying allegiance to any System Lord. They are massacred by one of their own who had been infected by a Prior in "Arthur's Mantle". The third Jaffa faction are the Illac Renin ("Kingdom of the Path"), who follow Origin in the belief that the Ori will Ascend them upon death. Their leader, Arkad, is killed by Teal'c in "Talion".

Also called Anubis drones or Supersoldiers, the Kull Warriors are creatures created by the Goa'uld Anubis as a personal army to replace his Jaffa as foot soldiers. They consist of a genetically engineered humanoid form given life using Ancient healing technology, and implanted with a mentally "blank" Goa'uld symbiote to make it subservient. This results in a creature that is utterly obedient to its master.[58] A Kull Warrior possesses much greater strength and stamina than a human and are relentless and single-mindedly focused on their goal; they will ignore any enemies that stay out of their way.[58] The Kull Warrior is bonded to armour that is impervious to almost all firearms, energy weapons, and explosives. Stargate Command and the Tok'ra eventually find a way to counteract the Kull Warriors' life-sustaining energy.

One of the alliance of four great races, the Nox are a fairy-like people encountered by SG-1 on P3X-774 in "The Nox". They want nothing to do with humanity, viewing them as "young" and having "much to learn". The Nox can live to be hundreds of years old and have a great desire for wisdom and understanding. They are extreme pacifists and never employ violence for any reason, even to defend themselves. As they have the ability to render themselves and other objects invisible and intangible, as well as the ability to resurrect the dead, they never need to fight. They also have the ability to activate a Stargate wormhole without the use of a DHD. Although they outwardly seem to be primitive forest-dwellers, they possess advanced technology beyond that of the Goa'uld, including a floating city.[59] The Nox also appear in "Enigma" and "Pretense".

Not much is known of this species, but they seem to be a highly advanced race who are eager to obtain Destiny's secrets. They have attacked Destiny with the intention of boarding it on numerous occasions. They kidnapped Rush and Chloe in an attempt to gain key knowledge of destiny. During their captivity a locator beacon was implanted in Rush's body which enabled the aliens to track Destiny.

An ancient amphibious species which appear in the Season 1 episode "Fire and Water".

A major threat in the cosmos, the Ori are Ascended beings who use their advanced knowledge of the universe to force lesser beings to worship them. In essence, they used to be Ancients, however they split into separate groups due to different views of life. The Ori are religious while the Ancients prefer science. The Ori sway lesser-developed planets into worshiping them by promising Ascension through an invented and empty religion called "Origin". This religion states that they created humanity and as such are to be worshiped by their creations. It also promises its followers that, on death, they will Ascend. However, Origin was designed to channel energy from the human worshipers to the Ori. As such, the Ori never help anyone else Ascend because then they would have to share the power that they sap from their worshipers. Their ultimate goal is to completely destroy the Ascended Ancients, who they know as "the Others". All of their efforts, including their technology, are for the purpose of garnering worshipers.

As Ascended beings, the Ori do not interfere directly in the mortal plane. They use instead humans called Priors, which they artificially evolve so that they are one step from Ascension, giving the Priors godlike powers. Because the Ori have worshipers across the entire home galaxy of the Ancients, and use their knowledge to spread, they are nearly unstoppable. For example: Ori warships, built using conventional means while operated through the supernatural abilities of the Priors, are generally considered to be the most powerful vessels in the Stargate universe.

The Ori might be regarded as a shadow form of the Goa'uld, with the significant difference that the Ori promise transcension to their followers but never provide it.[10] The moral balance between the Ancients and the Ori clearly echoes that of the Goa'uld and the Tok'ra.

Reol The Reol are a race of humanoid aliens, supposedly from the Milky Way. They are a peaceful race who were almost wiped out by the Goa'uld. They were forced to abandon their home world because of the Goa'uld. Reol have a unique natural defense; one of their bodily secretions is used to create false memories and illusions when it comes into contact with a living creature. Their appearance are tall, lanky bipedal creatures with thick strands of hair and dark black eyes. Their heads appear almost skeletal in shape. The Reol have also decided not to embrace technology to the extent that no other species have. [41]

A potent mechanical lifeform using a kiron-based technology composed of building blocks using nanotechnology. They strive to increase their numbers and spread across the universe by assimilating advanced technologies. They are hostile to all other lifeforms in the universe, but are opposed primarily by the Asgard. In the episode "Unnatural Selection", the Replicators had developed human-form Replicators, based on the technology they extracted from their Android creator, that appear just like humans and are able to change their form. Standard Replicators are resistant to energy weapons, and can only be destroyed by projectile weapons. Human-form Replicators, on the other hand, are resistant to projectile weapons as well due to the change in their nature from large blocks to smaller units the size of organic cells (cell blocks).

In the episode "New Order (Part 2)", an Ancient weapon called the Replicator Disruptor was developed by Jack O'Neill while he still had the knowledge of the Ancients in his mind. It works by blocking the cohesion between the blocks that make up the Replicators. The Replicators in the Milky Way galaxy were wiped out by the Dakara Superweapon in the two-part episode "Reckoning" at the climax of Season 8. It has been indicated that the Asgard used the same technology to defeat the Replicators in their own home galaxy as well.

Re'tu: Invisible non-humanoid aliens. A small terrorist like group of these beings wage war on the Goa'uld by eliminating humans as their potential hosts. They operate in 5-man suicide units, which are capable of setting off an explosion equivalent to a small tactical nuke.

Sakari: An ancient silicon-based lifeform, which uses severe hallucinations into manipulating others. The Sekkari are an extinct civilization that distributed devices across the Pegasus galaxy. These "seed carriers" contained the means to begin their evolution again on other worlds, as well as a repository of knowledge to tell the Sekkari descendants everything that once was. They are also the only known silicon-based lifeform in both the Pegasus and the Milky Way galaxy.[41]

Serrakin: An advanced race that has lived together in a largely harmonious society on the planet Hebridan.

Shadow entity: Accidentally released from a container, it roams looking for energy to feed on, and the more it feeds, the more lethal it becomes.

Spirits: Advanced aliens that, for a millennium, have been the object of a religion among the Salish ago.

Stragoth: Aliens that use a frequency-based technology to mimic the appearance of other beings, i.e. humans.

The Unas (meaning "First Ones") are the original hosts used by the Goa'uld on their homeworld of P3X-888, first seen in "Thor's Hammer". A race of large and primitive humanoids, the Unas possess great physical strength and have been exploited for physical labor by both Goa'uld and humans.[60][61] Their strength is enhanced even further when they are taken as Goa'uld hosts, and the symbiote is additionally able to heal even grievous injuries.[42][62]

The Unas are a tribal society living in close-knit communities with defined territories. Each tribe is led by a dominant alpha male leader.[61][63] They have limited stone age-level technology, but are more culturally sophisticated than is apparent at first glance and have established codes of behavior and honor. One of the most valuable possessions of an Unas is a necklace made of bone, which prevents Goa'uld symbiotes from burrowing into their necks.[63] The Unas speak their own language that varies between planets but is close enough to be mutually intelligible.[61] Only Goa'uld-possessed Unas have been shown to speak any language other than their own.[42] In "The First Ones", Daniel Jackson is able to decipher the Unas language and befriend a young Unas named Chaka.

In "Beast of Burden", it is shown that a race of humans from another unnamed world use Unas as slaves. A group of slavers from this planet learn the location of the Unas home world, and launched an expedition to capture more Unas. On this expedition, Chaka was captured. SG-1 subsequently followed them to rescue Chaka, and although they were successful, Chaka chose to remain on the planet to lead a rebellion to free his people.

Unity: Alien life that forms unstable doubles of people.

The Ursini[64] first appear in "Awakening". They are small bipedal aliens, but are agile. Their skin is a greenish grey color. They were in pods when Destiny docked with the Seed Ship. These pods were subsequently found aboard a heavily damaged ship floating in space. The pods were uninhabited this time. When Telford was stranded on the Seed Ship with them, they used the pods to transfer their knowledge to him (by the use of a neural interface), and together they repaired the Seed Ship. Eventually coming to Destiny's rescue when it was being attacked by the same Drone Ships that destroyed the Ursini's ships.[65] It is learned that the seedship Ursini are the last of their race, as no communication with any other Ursini can be established. The Ursini die with the seedship on an attack run on the second Drone Command Ship.[37]

Water lifeform: Microscopic beings that live in, and control, water.

A vampire-like telepathic race who feed on the "life-force" of humans. While intelligent humanoids, they are genetically close to insects. They evolved in the Pegasus galaxy after a human population seeded by the Ancients was fed upon by an insect called the irratus bug, which has the ability to draw upon a human's life to heal itself. As they fed, the bugs incorporated human DNA into themselves, giving rise to the Wraith.[66] The Wraith too feed on humans, treating them akin to livestock and regarding the act of feeding as nothing more than natural predation.[4] Their existence is restricted to waking en masse every few centuries to replenish their health by galaxy-wide abductions of humans called "cullings." A small selection of Wraith were tasked with remaining active during this time to maintain watch on the galaxy to prevent human reprisals.[4]

The main antagonists in Stargate Atlantis, the Wraith, are the dominant species in the Pegasus Galaxy. They are biologically immortal hive-based humanoids who feed on the "life-force" of humans, causing them to "lose years" in a way similar to aging. The Wraith drove the Ancients out of Pegasus 10,000 years ago; they now maintain the human worlds of the Pegasus Galaxy as sources of food. The arrival of the Atlantis Expedition in the Pegasus Galaxy leads to the Wraith waking prematurely from their hibernation; the human population of the Pegasus Galaxy is not enough to sustain all of the waking Wraith. To sate their hunger, the Wraith try to get to Earth whose population is much bigger than that of the whole Pegasus Galaxy. This can only be achieved either through the Stargate or by getting more advanced Hyper drive technology, both of which are present in Atlantis. After the expedition tricked them into thinking the city was destroyed, the Wraith began a brutal civil war.

One Wraith, whom Sheppard named Todd, was particularly cooperative after he was rescued from the Genii by him; Todd subsequently aides the expedition's efforts for mutual gain.

Although most known habitable planets in the Stargate universe are populated by humans, there was once an Alliance of four great races. A strategic alliance of the four advanced species was built over many millennia since before the rise of the Goa'uld. In "The Torment of Tantalus", SG-1 discovers a meeting place for the alliance on the planet Heliopolis. There they find a chamber showing the written languages of the four races, as well as a hologram of a common language based on graphical representations of the 146 known (to them) chemical elements. This is possibly derived from the H. Beam Piper novelette Omnilingual in which a similar scene takes place. In the season 2 episode "The Fifth Race", Jack O'Neill learns from the Asgard that the alliance consisted of the Ancients, the Asgard, the Furlings, and the Nox. The Asgard also say that humanity has taken the first steps towards becoming "the Fifth Race". In the Stargate SG-1 finale "Unending", Thor declares the Tau'ri are the Fifth Race.

The Tok'ra (literally "against Ra", the Supreme System Lord) are a faction of Goa'uld symbiotes who are opposed to the Goa'uld culturally and militarily. Spawned by the queen Egeria, they live in true symbiosis with their hosts, both beings sharing the body equally and benefiting from each other. Although they have few members, the Tok'ra have fought the Goa'uld for thousands of years, favoring covert tactics and balancing the various System Lords against one another. Since season 2 of Stargate SG-1, the Tok'ra have become valuable allies of Earth.

The Athosians are a group of hunters, farmers, and traders from the planet Athos. First introduced in "Rising", they are the first humans encountered by the Atlantis Expedition in the Pegasus galaxy. The Athosians were once technologically advanced, but reverted to a pre-industrial state to avoid the Wraith. Following their contact with the Expedition, the Athosians move to Lantea and their leader, Teyla Emmagan, joins Major Sheppard's team. In "The Gift", it is revealed that some Athosians possess Wraith DNA, resulting from an old Wraith experiment to make humans more "palatable". This allows these individuals to sense the presence of Wraith, to tap into their telepathic communications, and to control Wraith technology. In the third season episode "The Return", the Athosians are asked to leave Lantea by a group of surviving Ancients reclaiming Atlantis from Earth. The Athosian population is subsequently found to have disappeared from New Athos in "Missing". The search for the missing Athosians and their fate at the hands of the rogue Wraith Michael contributes to a major plot arc near the end of the fourth season.

The Genii appear to be simple farmers, but are in fact a military society with technology comparable to 1940s Earth. First appearing in "Underground", the Genii were once a formidable human confederation until the Wraith vanquished the Ancients 10,000 years ago, and the subsequent victory forced them into hiding in subterranean bunkers during cullings. They have since built their entire civilization underground, and devoted their existence to developing technology such as fission bombs to destroy the Wraith. Their collective desire for revenge has made them paranoid and hostile towards others and they pursue their aims regardless of the cost to anyone else. They become enemies of the Atlantis Expedition in the first season when they attempted to seize an SG team's puddle jumper and weapons, and once try to invade Atlantis,[67][68] though after a coup d'etat in the second season they have been more favorable towards cooperation with the city.[69]

The Satedans are the people of Ronon Dex, who joins the Atlantis Expedition in the season 2 episode "Runner". In that episode, it is revealed that the Satedans were a civilization comparable in technology to Earth in the mid-20th century, but met the fate of all advanced civilizations in Pegasus when their homeworld Sateda (P3R-534) was devastated seven years ago by the Wraith. In "Trinity", Ronon discovers that some 300 Satedans survived the attack in shelters west of the capital and later moved onto other planets like Ballkan and Manaria. In "Reunion", Ronon encounters more Satedans, his former military comrades, who have been converted into Wraith worshipers.

The Travelers are humans who live on a fleet of ships to avoid the Wraith, introduced in "Travelers". Although not as technologically advanced as the Ancients, the Travelers possess hyperdrives and advanced weapons. Due to their population outgrowing their available space, the Travelers had been forced to abandon some of their people on planets. Their discovery of an Aurora-class battleship promised to solve this problem, but without the ATA gene they were unable to operate it. They kidnap John Sheppard and extort him to create an interface for them. Though uncooperative at first on account of his abduction, Sheppard and the Traveler leader Larrin eventually came to an understanding after a mutual experience with the Wraith. In "Be All My Sins Remember'd", the Travelers become concerned by the Asuran Replicator threat after one of their trading partners is wiped out. Several of their ships, including their Ancient battleship, join the Atlanteans and the Wraith in battling the Replicators over their homeworld. According to producers Joseph Mallozzi and Paul Mullie, the Travelers were created as a "wild card" like the Genii, but with advanced technology that would make them a "challenge" for the Atlantis team. Their lifestyle was devised as a way around the established fact that the Wraith wipe out any civilizations that approach them in technological advancement.[70]

Dakara is the planet where the Ancients first landed in the Milky Way Galaxy after fleeing the Alteran Galaxy. It is here where they later built a powerful device, capable of destroying existing life or creating it where there was none before, long before the galaxy was colonized by the Goa'uld or the humans.[71] Long after the Ancients disappeared, the Goa'uld System Lords eventually took possession of the planet, unknowing of its history. The place eventually became a holy ground for their Jaffa servant race since they held legends which described Dakara as the planet where their enslavement began. At the Temple of Dakara, Jaffa were given their strength and longevity through the first implantation of symbiotes. The temple is therefore the ultimate holy ground of the Goa'uld, who kept the Jaffa loyal by propagating lies that they were gods. The idea of stepping into Dakara was unthinkable to the free Jaffa.[72]

After the Replicators start to invade the galaxy in season 8, killing Goa'uld and taking over their fleets, Bra'tac and Teal'c decide this to be the best time to take over Dakara. Dakara easily falls to the rebellion, and the capture of the planet proves to the majority of Jaffa still in servitude that the Goa'uld were not in fact gods. This leads to a general revolt by the Jaffa against their masters. Also, the final battle with the Replicators occurs here which results in their destruction by the Dakara superweapon. Combined with the weakened state the Goa'uld are left in after their war with the Replicators, this resulted in the fall of the System Lords and the collapse of the Goa'uld Empire.[72] Shortly after, the Free Jaffa Nation is declared, with Dakara being made the capital.[71] Two seasons later, Adria sets course for Dakara, destroying the weapon and conquering the planet in the process.[73] After the loss of Dakara, the Free Jaffa Nation begins to fracture into several warring factions, some of which blame the Tau'ri for the devastation of Dakara.[74] In Stargate: The Ark of Truth SG-1 returns to the ruins of Dakara in search of the weapon that could stop the invasion of the Milky Way galaxy by the Ori Crusade.

Stargate Atlantis is set in the dwarf galaxy Pegasus. In reality, there are two galaxies in the Local Group called Pegasus Dwarf; the Pegasus Dwarf Spheroidal Galaxy and the Pegasus Dwarf Irregular Galaxy. It has not been explicitly stated which of these is the galaxy in Stargate Atlantis. However, in this discussion regarding the new McKay-Carter Intergalactic Gate Bridge, General Hank Landry states that the distance between the Pegasus and Milky Way galaxies is "three million light-years," suggesting that the series takes place in the Pegasus Dwarf Irregular Galaxy.[75] Also, in a few episodes the Pegasus galaxy has been seen from between the Milky Way and Pegasus, showing an irregular galaxy.

Unlike what happened in the Milky Way, the human population of the Pegasus galaxy is a product of Ancient seeding. The Lanteans arrived in the Pegasus galaxy via the Ancient city ship of Atlantis. As there was seldom interbreeding between the Ancients and humans, the ATA gene is virtually non-existent amongst the natives of Pegasus. Few human races in Pegasus surpass Earth in technological advancement, as the Wraith destroy any such civilizations as potential future threats to their dominance.

Atlantis is an Ancient city equipped with intergalactic hyperdrive engines that serves as the base of operations for the main SGA characters, from which they explore other planets through the Stargate. According to the mythology of the show, the city was built by an advanced race known as the Ancients originally as a central outpost in prehistorical Antarctica, until an unexplained crisisinvolving a virulent plagueforced them to relocate the city to the planet Lantea in the Pegasus Galaxy. The Ancients (known as "Ancestors" to the denizens of Pegasus, "Lanteans" to the Wraith) submerged the city around 8,000 BCE to evade Wraith detection and returned via stargate to Earth, where survivor recollections formed the basis for the ancient Greek accounts of Lost City of Atlantis. As the humans from Earth inhabit the fabled City of the Ancestors after the series pilot of Stargate Atlantis, some Pegasus cultures believe the SGA members to be the Ancients returned.[4][76]

Ascension is a process by which sufficiently evolved sentient beings may shed their physical bodies and live eternally as pure energy on a higher plane of existence, where their capacity for learning and power grows exponentially. It is a mental, spiritual, or evolutionary enlightenment that can arise as the direct result of achieving a certain level of wisdom and self-knowledge. Ascension was once employed by the Ancients as a means to avoid several issues threatening their species with extinction, but it is sought by major powers on Earth and other races such as the Jaffa later. The concept is introduced in the SG-1 season 3 episode "Maternal Instinct" and becomes a central theme of Stargate SG-1 and Stargate Atlantis.

Ascension can happen in one of two ways: evolutionarily or spiritually. Ascension can occur when a human evolves the ability to use approximately 90% of his or her brain capacity.[77] The Ancients who ascended naturally reached this point without the aid of technology. They, however, developed the DNA Resequencer, a device capable of enhancing humans so that they would gain telepathy; telekinesis; superhuman senses, speed, and strength; precognition; perfect health; the ability to self-heal rapidly and the power to heal by touch; and the ability to use many parts of their mind and fully focus on a single thing.[78] Spiritual ascension can occur through meditation when one is pure of spirit and in the search for enlightenment,[71] has a fully opened mind,[79] and has shed one's fears and attachment to the mortal world.[80] In the process of ascension through meditation, many beings obtain the same supernatural abilities that users of the DNA resequencer receive. In some cases, however, no level of spiritualism can help with ascension: the Asgard's genetic degradation was so severe that they could not ascend, in spite of the fact that many of them would otherwise have been good candidates.

The ascended Ancients maintain a strict rule of noninterference in mortal affairs. If broken, this rule may result in forceful de-ascension or other punishment by the other ascended beings.[81] The Ori, on the other hand, seek to increase their power by any means, including destroying their former compatriots, the Ancients, in a crusade against the Milky Way Galaxy. The power of an ascended being can be negated through the Sangraal, a device that the Ancient Merlin gave up his life to create to battle the Ori.[82]

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Legaltech News – Law Technology News

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eDiscovery in 2016: A Comprehensive Guide for Legal Professionals Here you will find cutting-edge resources covering the latest trends and news in eDiscovery all dedicated to making you the best in your field. Complimentary White Paper: eDiscovery without Borders This white paper discusses the legal restrictions of foreign ESI, best practices for processing and review, and more. An In-House Counsel's Guide to eDiscovery For practiced in-house counsel, managing eDiscovery can be like suddenly living in a country where nobody speaks your language. This white paper offers best practices, a comprehensive map of the eDiscovery terrain, and tips for effective eDiscovery efforts. Complimentary White Paper: Mitigating Risk in Handling eDiscovery This white paper takes a deep dive on the subject of U.S Export Control laws and regulations, and how they dictate your eDiscovery efforts. Legal drafting technology with precision and reassurance Legal drafting can be time-consuming, costly, and - let's face it - less than stimulating. Learn how legal drafting technology can prove an essential partner here.

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IHS Technology The Source for Critical Information and …

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iPhone 7: analysis and teardown

Apple just released its new generation of iPhones: the iPhone 7 and iPhone 7 Plus. And weve got it covered.

Catch up with the expert take of our thought leaders on current hot issues, trendsetting topics and other provocative subjects.

IHS Technology provides analysis, data and expertise on everything from raw materials to networks to consumers.

January 5-8, 2017 | Las Vegas, NV

IHS shows a deep understanding of the industry and the underlying market trends...

Johan Jubbega, Senior VP Sales EMEA (Bosch Security Systems)

Market reports from IHS are a true asset, bringing real understanding...

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We are the leading source of information, insight and analytics in critical areas that shape the technology ecosystemfrom materials and components, to devices and equipment, to end markets and consumers. Clients worldwide rely on the independent insights of our 300+ analysts in sectors spanning IT, telecom, media, industrial, automotive, electronics, solar and more.

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Technology | NFL Football Operations

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Each week, millions of people watch NFL games on their televisions or in person. Increasingly, they also follow the action on a second or even a third screen. Smartphones, tablets and computers let fans follow their fantasy teams, talk about football on social media or even watch another game, all from the stadium or the couch.

We respect our traditions, but we embrace evolution.

Michelle McKenna-Doyle, NFL Chief Information Officer

Fans are certainly aware of how technology has changed their experience of watching games. They may not always notice, though, how technology has changed the game itself for the betterment of the league, coaches and players, and even the fans.

Television may have changed the league more than any other technology, and it certainly enabled many of the leagues biggest advancements. It fueled the dramatic increase in the NFLs popularity and profitability. The instant replay system emerged from and was a result of improved broadcast technology. Teams use footage to evaluate and coach players, and the league uses it to grade officials. Television also has led clubs to upgrade stadiums including the installation of enormous video displays to compete with the viewing experience at home.

Television isnt the only technology to have affected the game. Advancements have allowed the NFL to evaluate and improve officiating and protect players. Technology helps players and teams communicate and gives coaches the tools needed to create game plans and to adjust them on the fly.

Learn more abouttelevision's impact on the NFL

It speeds up the pace of games, ensures that each contest runs fairly and smoothly and improves the fan experience for those watching on television and those at the games.

State-of-the-art technology powers the command center the league uses to monitor games and evaluate its officials, drives the instant replay system that assists officials in getting calls right, and enables the wireless communications coaches, players and officials use during games.

Dean Blandino, NFL senior vice president of officiating, takes you behind the scenes at Art McNally GameDay Central the leagues officiating command center.

Technology provides players with electronic playbooks and position-specific game film on club-provided tablets. As the game unfolds, coaches can dissect opponents offense and defense on league-provided tablets.

Technology also helps better protect the players. Its impact is felt in sturdier playing surfaces and more advancedpads and helmets.It allows teams to keep electronic medical records to better treat players and allows certified athletic trainers to use video to spot possible concussions and other potential injuries during games.

All of this technology presents challenges for NFL Football Operations staff. This is particularly demanding on gameday, when it all must operate smoothly for a fast-paced, time-sensitive, live event that at best is unpredictable and is sometimes played in bad weather. Making it all work requires attention to detail and the technical knowledge to troubleshoot on the fly.

Game Operations staff must check every system before a game, identify and prevent radio frequency conflicts, and address technological problems, even as the action continues. A tremendous amount of coordination is required not only internally, but also with teams, broadcasters, stadium staff and emergency services.

Each week, NFL frequency coordinators must navigate countless spectrum conflicts. Licensed bandwidth from the Federal Communications Commission continues to shrink as demand continues to grow. Frequency coordinators make sure anyone using a wireless microphone, walkie-talkie or radio is on the correct channel to allow as many people as possible to access the bandwidth they need. Without this, the long list of people who need to access the spectrum each game could find themselves fighting over the same frequencies and unable to perform their jobs properly.

That massive collision is happening in our stadiums every weekend, said Michelle McKenna-Doyle, the leagues chief information officer. That has to get solved whether we buy, rent or partner with someone who owns frequency.

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Urban Dictionary: technology

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1) The application of science, math, engineering, art, and other fields of knowledge to create tools and implementations deemed useful by a society.

2) Anything that has to do with computers. Often misused by stupid people and corporations that market to said stupid people.

The latest technology is Blu-ray.

Lotsa space for your liquids.

Lotsa space for your liquids.

Your favorite word on a white mug.

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Soft and offensive. Just like you.

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

Something that will eventually destroy society, make obesity the new "average" weight, and cause mass unemployment.

Damn technology.

Lotsa space for your liquids.

Lotsa space for your liquids.

Your favorite word on a white mug.

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Soft and offensive. Just like you.

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

in economics: not a resource, but part of the production process. Anything that increases the performance of an resource without the change in resources.

In war, a country with the comparitive advantage in national defense, has a greater availability of technology that increases their performance without the need of a large quantity of troops.

Lotsa space for your liquids.

Lotsa space for your liquids.

Your favorite word on a white mug.

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Soft and offensive. Just like you.

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

n. anything that was invented after you were born

"Technology is killing me."

Lotsa space for your liquids.

Lotsa space for your liquids.

Your favorite word on a white mug.

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Soft and offensive. Just like you.

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

First coined by young ingenue Judy Alexander, "Technologies" is a term for any kind of awkward social interactions/dynamics. It can be used as either an adjective or a noun.

Or:

Don't listen to those girls and what they say about you, they don't know anything, it's just technologies.

Lotsa space for your liquids.

Lotsa space for your liquids.

Your favorite word on a white mug.

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Soft and offensive. Just like you.

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

Something that allows one to talk with hot babes on the internet all day.

"I love technology, but not as much as you, you see. Still, I love technology... Always and Forever"

Lotsa space for your liquids.

Lotsa space for your liquids.

Your favorite word on a white mug.

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Soft and offensive. Just like you.

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

A pleasure inducing entity for those who consider themselves gadgeteers. Involves locking oneself in one's room and playing with objects of a technological nature. Often times people with lisp's or strange voices who can not socialize normally because of their impediment are accustomed to a love of technological activities as well as hold a fondness for all sorts of gadgets.

"Technology rules!" (commonly shouted by gadgeteers in conjuction with a hand sign meaning "I am a loser!")

Lotsa space for your liquids.

Lotsa space for your liquids.

Your favorite word on a white mug.

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Soft and offensive. Just like you.

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

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Rationalism verses Empiricism – dummies.com

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The history of philosophy has seen many warring camps fighting battles over some major issue or other. One of the major battles historically has been over the foundations of all our knowledge. What is most basic in any human set of beliefs? What are our ultimate starting points for any world view? Where does human knowledge ultimately come from?

Empiricists have always claimed that sense experience is the ultimate starting point for all our knowledge. The senses, they maintain, give us all our raw data about the world, and without this raw material, there would be no knowledge at all. Perception starts a process, and from this process come all our beliefs. In its purest form, empiricism holds that sense experience alone gives birth to all our beliefs and all our knowledge. A classic example of an empiricist is the British philosopher John Locke (16321704).

Its easy to see how empiricism has been able to win over many converts. Think about it for a second. Its interestingly difficult to identify a single belief that you have that didnt come your way by means of some sense experience sight, hearing, touch, smell, or taste. Its natural, then, to come to believe that the senses are the sole source and ultimate grounding of belief.

But not all philosophers have been convinced that the senses fly solo when it comes to producing belief. We seem to have some beliefs that cannot be read off sense experience, or proved from any perception that we might be able to have. Because of this, there historically has been a warring camp of philosophers who give a different answer to the question of where our beliefs ultimately do, or should, come from.

Rationalists have claimed that the ultimate starting point for all knowledge is not the senses but reason. They maintain that without prior categories and principles supplied by reason, we couldnt organize and interpret our sense experience in any way. We would be faced with just one huge, undifferentiated, kaleidoscopic whirl of sensation, signifying nothing. Rationalism in its purest form goes so far as to hold that all our rational beliefs, and the entirety of human knowledge, consists in first principles and innate concepts (concepts that we are just born having) that are somehow generated and certified by reason, along with anything logically deducible from these first principles.

How can reason supply any mental category or first principle at all? Some rationalists have claimed that we are born with several fundamental concepts or categories in our minds ready for use. These give us what the rationalists call innate knowledge. Examples might be certain categories of space, of time, and of cause and effect.

We naturally think in terms of cause and effect. And this helps organize our experience of the world. We think of ourselves as seeing some things cause other things to happen, but in terms of our raw sense experience, we just see certain things happen before other things, and remember having seen such before-and-after sequences at earlier times. For example, a rock hits a window, and then the window breaks. We dont see a third thing called causation. But we believe it has happened. The rock hitting the window caused it to break. But this is not experienced like the flight of the rock or the shattering of the glass. Experience does not seem to force the concept of causation on us. We just use it to interpret what we experience. Cause and effect are categories that could never be read out of our experience and must therefore be brought to that experience by our prior mental disposition to attribute such a connection. This is the rationalist perspective.

Rationalist philosophers have claimed that at the foundations of our knowledge are propositions that are self-evident, or self-evidently true. A self-evident proposition has the strange property of being such that, on merely understanding what it says, and without any further checking or special evidence of any kind, we can just intellectually see that it is true. Examples might be such propositions as:

The claim is that, once these statements are understood, it takes no further sense experience whatsoever to see that they are true.

Descartes was a thinker who used skeptical doubt as a prelude to constructing a rationalist philosophy. He was convinced that all our beliefs that are founded on the experience of the external senses could be called into doubt, but that with certain self-evident beliefs, like I am thinking, there is no room for creating and sustaining a reasonable doubt. Descartes then tried to find enough other first principles utterly immune to rational doubt that he could provide an indubitable, rational basis for all other legitimate beliefs.

Philosophers do not believe that Descartes succeeded. But it was worth a try. Rationalism has remained a seductive idea for individuals attracted to mathematics and to the beauties of unified theory, but it has never been made to work as a practical matter.

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Logic: Rationalism vs. Empiricism – Theology

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D. Rationalism vs. Empiricism

Theories of knowledge divide naturally, theoretically and historically into the two rival schools of rationalism and empiricism. Neither rationalism nor empiricism disregards the primary tool of the other school entirely. The issue revolves on beliefs about necessary knowledge and empirical knowledge.

1. Rationalism

Rationalism believes that some ideas or concepts are independent of experience and that some truth is known by reason alone.

a. a priori

This is necessary knowledge not given in nor dependent upon experience; it is necessarily true by definition. For instance "black cats are black." This is an analytic statement, and broadly, it is a tautology; its denial would be self-contradictory.

2. Empiricism

Empiricism believes that some ideas or concepts are independent of experience and that truth must be established by reference to experience alone.

b. a posteriori

This is knowledge that comes after or is dependent upon experience. for instance "Desks are brown" is a synthetic statement. Unlike the analytic statement "Black cats are black", the synthetic statement "Desks are brown" is not necessarily true unless all desks are by definition brown, and to deny it would not be self-contradictory. We would probably refer the matter to experience.

Since knowledge depends primarily on synthetic statements -- statements that may be true or may be false -- their nature and status are crucial to theories of knowledge. The controvercial issue is the possibility of synthetic necessary knowledge -- that is, the possibility of having genuine knowledge of the world without the need to rely on experience. Consider these statements:

1) The sum of the angles of a triangle is 180 degrees.

2) Parallel lines never meet.

3) A whole is the sum of all its parts.

Rationalism may believe these to be synthetic necessary statements, universally treu, and genunie knowledge; i.e., they are not merely empty as the analytic or tautologous statemenst (Black cats are black) and are not dependent on experience for their truth value.

Empiricism denies that these statements are synthetic and necessary. Strict empriicism asserts that all such statements only appear to be necessary or a priori. Actually, they derive from experience.

Logical empiricism admits that these statements are ncessary but only because they are not really synthetic statements but analytic statements, which are true by definition alone and do not give us genuine knowledge of the world.

GENUINE KNOWLEDGE

Rationalism includes in genuine knowledge synthetic necessary statements (or, if this term is rejected, then those analytic necessary statements that "reveal reality" in terms of universally necessary truth; e.g., "An entity is what it is and not something else.")

Empiricism limits genuine knowledge to empirical statements. Necessary statements are empty (that is, they tell us nothing of the world).

Logical empiricism admits as genuine knowledge only analytic necessary (Black cats are black) or synthetic empirical statements (desks are brown). But the anyalytic necessary statements or laws of logic and mathematics derive from arbitrary rules of usage, definitions, and the like, and therefore reveal nothing about reality. (This is the antimetaphysical point of view).

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Rationalism vs. Empiricism Essay – 797 Words – StudyMode

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In Philosophy, there are two main positions about the source of all knowledge. These positions are called rationalism and empiricism. Rationalists believe that all knowledge is "innate", or is there when one is born, and that learning comes from intuition. On the other hand, empiricists believe that all knowledge comes from direct sense experience. In this essay, I will further explain each position, it's strengths and weaknesses, and how Kant discovered that there is an alternative to these positions. The thesis I defend in this essay is that knowledge can be of both positions.

According to Rationalists (such as Descartes), all knowledge must come from the mind. Rationalism is concerned with absolute truths that are universal (such as logic and mathematics), which is one of the strengths of this position. It's weakness lies in the fact that it is difficult to apply rationalism to particulars (which are everywhere in our daily life!) because it is of such an abstract nature.

According to Empiricists, such as John Locke, all knowledge comes from direct sense experience. Locke's concept of knowledge comes from his belief that the mind is a "blank slate or tabula rosa" at birth, and our experiences are written upon the slate. Therefore, there are no innate experiences. The strength of the empiricist position is that it is best at explaining particulars, which we encounter on a daily basis. The weakness of this position is that one cannot have direct experiences of general concepts, since we only experience particulars.

Noticing that rationalism and empiricism have opposing strengths and weaknesses, Kant attempted to bring the best of both positions together. In doing so he came up with a whole new position, which I will soon explain.

Kant claimed that there are 3 types of knowledge. The first type of knowledge he called "a priori", which means prior to experience. This knowledge corresponds to rationalist thinking, in that it holds knowledge to be...

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Rationalism vs. Empiricism Essay - 797 Words - StudyMode

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NATO: Russian Aircraft Intercepted 110 Times Above Baltic in 2016

Posted: at 10:49 am

Russian military aircraft near the Baltic Sea were intercepted by NATO jets 110 times in 2016.

The number of intercepts was lower than the 160 recorded in 2015 and the 140 in 2014, Lithuanias Ministry of Defense said in a statement to Baltic news agency BNS. NATO has confirmed these figures to Newsweek.

However, this greatly exceeds the number of aerial encounters above the Baltic Sea before Russias annexation of Crimea in 2014; in 2013, NATO jets intercepted Russian aircraft 43 times.

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Major General Thierry Dupont, commander of NATOs Combined Air Operations Center, says that the number of intercepts has increased since 2014 because Russia is flying more aircraft in Baltic airspace, but also because the alliance has increased its air policing capabilities.

The vast majority of the interceptions were made before any incursion into sovereign allied airspace, although over the last 12 months Estonia has reported at least six airspace violations by Russian jets. Moscow has denied the accusations.

One of NATOs roles is to preserve the integrity of the Allies airspace, Dupont tells Newsweek. Missions like the Baltic Air Policing (BAP) demonstrate NATOs resolve and capability to ensure protection across allies airspace, including those allies that do not have their own Air Policing assets.

According to Dupont, the drop in intercepts over the Baltic in 2016 could be due to a shift in Russias focus towards operations in Syria in 2016.

Overall allied scrambles increased in 2016, compared to 2014 and 2015, largely because they also now account for Turkish Air Force patrolswhich are often under NATO commandalong Turkeys border with Syria.

The BAP mission is a rotational deployment in which all NATO members can participate to provide the Baltic states with an air force, in the form of four-month deployments. On Thursday, the French and German deployments at NATOs bases in Siauliai, Lithuania, and in Amari, Estonia, will be replaced by a Dutch deployment.

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NATO: Russian Aircraft Intercepted 110 Times Above Baltic in 2016

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DNA replication – Wikipedia

Posted: at 10:45 am

In molecular biology, DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. This process occurs in all living organisms and is the basis for biological inheritance. DNA is made up of a double helix of two complementary strands. During replication, these strands are separated. Each strand of the original DNA molecule then serves as a template for the production of its counterpart, a process referred to as semiconservative replication. Cellular proofreading and error-checking mechanisms ensure near perfect fidelity for DNA replication.[1][2]

In a cell, DNA replication begins at specific locations, or origins of replication, in the genome.[3] Unwinding of DNA at the origin and synthesis of new strands results in replication forks growing bi-directionally from the origin. A number of proteins are associated with the replication fork to help in the initiation and continuation of DNA synthesis. Most prominently, DNA polymerase synthesizes the new strands by adding nucleotides that complement each (template) strand. DNA replication occurs during the S-stage of interphase.

DNA replication can also be performed in vitro (artificially, outside a cell). DNA polymerases isolated from cells and artificial DNA primers can be used to initiate DNA synthesis at known sequences in a template DNA molecule. The polymerase chain reaction (PCR), a common laboratory technique, cyclically applies such artificial synthesis to amplify a specific target DNA fragment from a pool of DNA.

DNA usually exists as a double-stranded structure, with both strands coiled together to form the characteristic double-helix. Each single strand of DNA is a chain of four types of nucleotides. Nucleotides in DNA contain a deoxyribose sugar, a phosphate, and a nucleobase. The four types of nucleotide correspond to the four nucleobases adenine, cytosine, guanine, and thymine, commonly abbreviated as A,C, G and T. Adenine and guanine are purine bases, while cytosine and thymine are pyrimidines. These nucleotides form phosphodiester bonds, creating the phosphate-deoxyribose backbone of the DNA double helix with the nuclei bases pointing inward (i.e., toward the opposing strand). Nucleotides (bases) are matched between strands through hydrogen bonds to form base pairs. Adenine pairs with thymine (two hydrogen bonds), and guanine pairs with cytosine (stronger: three hydrogen bonds).

DNA strands have a directionality, and the different ends of a single strand are called the "3' (three-prime) end" and the "5' (five-prime) end". By convention, if the base sequence of a single strand of DNA is given, the left end of the sequence is the 5' end, while the right end of the sequence is the 3' end. The strands of the double helix are anti-parallel with one being 5' to 3', and the opposite strand 3' to 5'. These terms refer to the carbon atom in deoxyribose to which the next phosphate in the chain attaches. Directionality has consequences in DNA synthesis, because DNA polymerase can synthesize DNA in only one direction by adding nucleotides to the 3' end of a DNA strand.

The pairing of complementary bases in DNA (through hydrogen bonding) means that the information contained within each strand is redundant. Phosphodiester (intra-strand) bonds are stronger than hydrogen (inter-strand) bonds. This allows the strands to be separated from one another. The nucleotides on a single strand can therefore be used to reconstruct nucleotides on a newly synthesized partner strand.[4]

DNA polymerases are a family of enzymes that carry out all forms of DNA replication.[6] DNA polymerases in general cannot initiate synthesis of new strands, but can only extend an existing DNA or RNA strand paired with a template strand. To begin synthesis, a short fragment of RNA, called a primer, must be created and paired with the template DNA strand.

DNA polymerase adds a new strand of DNA by extending the 3' end of an existing nucleotide chain, adding new nucleotides matched to the template strand one at a time via the creation of phosphodiester bonds. The energy for this process of DNA polymerization comes from hydrolysis of the high-energy phosphate (phosphoanhydride) bonds between the three phosphates attached to each unincorporated base. Free bases with their attached phosphate groups are called nucleotides; in particular, bases with three attached phosphate groups are called nucleoside triphosphates. When a nucleotide is being added to a growing DNA strand, the formation of a phosphodiester bond between the proximal phosphate of the nucleotide to the growing chain is accompanied by hydrolysis of a high-energy phosphate bond with release of the two distal phosphates as a pyrophosphate. Enzymatic hydrolysis of the resulting pyrophosphate into inorganic phosphate consumes a second high-energy phosphate bond and renders the reaction effectively irreversible.[Note 1]

In general, DNA polymerases are highly accurate, with an intrinsic error rate of less than one mistake for every 107 nucleotides added.[7] In addition, some DNA polymerases also have proofreading ability; they can remove nucleotides from the end of a growing strand in order to correct mismatched bases. Finally, post-replication mismatch repair mechanisms monitor the DNA for errors, being capable of distinguishing mismatches in the newly synthesized DNA strand from the original strand sequence. Together, these three discrimination steps enable replication fidelity of less than one mistake for every 109 nucleotides added.[7]

The rate of DNA replication in a living cell was first measured as the rate of phage T4 DNA elongation in phage-infected E. coli.[8] During the period of exponential DNA increase at 37C, the rate was 749 nucleotides per second. The mutation rate per base pair per replication during phage T4 DNA synthesis is 1.7 per 108.[9]

DNA replication, like all biological polymerization processes, proceeds in three enzymatically catalyzed and coordinated steps: initiation, elongation and termination.

For a cell to divide, it must first replicate its DNA.[10] This process is initiated at particular points in the DNA, known as "origins", which are targeted by initiator proteins.[3] In E. coli this protein is DnaA; in yeast, this is the origin recognition complex.[11] Sequences used by initiator proteins tend to be "AT-rich" (rich in adenine and thymine bases), because A-T base pairs have two hydrogen bonds (rather than the three formed in a C-G pair) and thus are easier to strand separate.[12] Once the origin has been located, these initiators recruit other proteins and form the pre-replication complex, which unzips the double-stranded DNA.

DNA polymerase has 5'-3' activity. All known DNA replication systems require a free 3' hydroxyl group before synthesis can be initiated (note: the DNA template is read in 3' to 5' direction whereas a new strand is synthesized in the 5' to 3' directionthis is often confused). Four distinct mechanisms for DNA synthesis are recognized:

The first is the best known of these mechanisms and is used by the cellular organisms. In this mechanism, once the two strands are separated, primase adds RNA primers to the template strands. The leading strand receives one RNA primer while the lagging strand receives several. The leading strand is continuously extended from the primer by a DNA polymerase with high processivity, while the lagging strand is extended discontinuously from each primer forming Okazaki fragments. RNase removes the primer RNA fragments, and a low processivity DNA polymerase distinct from the replicative polymerase enters to fill the gaps. When this is complete, a single nick on the leading strand and several nicks on the lagging strand can be found. Ligase works to fill these nicks in, thus completing the newly replicated DNA molecule.

The primase used in this process differs significantly between bacteria and archaea/eukaryotes. Bacteria use a primase belonging to the DnaG protein superfamily which contains a catalytic domain of the TOPRIM fold type.[13] The TOPRIM fold contains an / core with four conserved strands in a Rossmann-like topology. This structure is also found in the catalytic domains of topoisomerase Ia, topoisomerase II, the OLD-family nucleases and DNA repair proteins related to the RecR protein.

The primase used by archaea and eukaryotes, in contrast, contains a highly derived version of the RNA recognition motif (RRM). This primase is structurally similar to many viral RNA-dependent RNA polymerases, reverse transcriptases, cyclic nucleotide generating cyclases and DNA polymerases of the A/B/Y families that are involved in DNA replication and repair. In eukaryotic replication, the primase forms a complex with Pol .[14]

Multiple DNA polymerases take on different roles in the DNA replication process. In E. coli, DNA Pol III is the polymerase enzyme primarily responsible for DNA replication. It assembles into a replication complex at the replication fork that exhibits extremely high processivity, remaining intact for the entire replication cycle. In contrast, DNA Pol I is the enzyme responsible for replacing RNA primers with DNA. DNA Pol I has a 5' to 3' exonuclease activity in addition to its polymerase activity, and uses its exonuclease activity to degrade the RNA primers ahead of it as it extends the DNA strand behind it, in a process called nick translation. Pol I is much less processive than Pol III because its primary function in DNA replication is to create many short DNA regions rather than a few very long regions.

In eukaryotes, the low-processivity enzyme, Pol , helps to initiate replication because it forms a complex with primase.[15] In eukaryotes, leading strand synthesis is thought to be conducted by Pol ; however, this view has recently been challenged, suggesting a role for Pol .[16] Primer removal is completed Pol [17] while repair of DNA during replication is completed by Pol .

As DNA synthesis continues, the original DNA strands continue to unwind on each side of the bubble, forming a replication fork with two prongs. In bacteria, which have a single origin of replication on their circular chromosome, this process creates a "theta structure" (resembling the Greek letter theta: ). In contrast, eukaryotes have longer linear chromosomes and initiate replication at multiple origins within these.>[18]

The replication fork is a structure that forms within the nucleus during DNA replication. It is created by helicases, which break the hydrogen bonds holding the two DNA strands together. The resulting structure has two branching "prongs", each one made up of a single strand of DNA. These two strands serve as the template for the leading and lagging strands, which will be created as DNA polymerase matches complementary nucleotides to the templates; the templates may be properly referred to as the leading strand template and the lagging strand template.

DNA is always synthesized in the 5' to 3' direction. Since the leading and lagging strand templates are oriented in opposite directions at the replication fork, a major issue is how to achieve synthesis of nascent (new) lagging strand DNA, whose direction of synthesis is opposite to the direction of the growing replication fork.

The leading strand is the strand of nascent DNA which is being synthesized in the same direction as the growing replication fork. A polymerase "reads" the leading strand template and adds complementary nucleotides to the nascent leading strand on a continuous basis.

The lagging strand is the strand of nascent DNA whose direction of synthesis is opposite to the direction of the growing replication fork. Because of its orientation, replication of the lagging strand is more complicated as compared to that of the leading strand. As a consequence, the DNA polymerase on this strand is seen to "lag behind" the other strand.

The lagging strand is synthesized in short, separated segments. On the lagging strand template, a primase "reads" the template DNA and initiates synthesis of a short complementary RNA primer. A DNA polymerase extends the primed segments, forming Okazaki fragments. The RNA primers are then removed and replaced with DNA, and the fragments of DNA are joined together by DNA ligase.

As helicase unwinds DNA at the replication fork, the DNA ahead is forced to rotate. This process results in a build-up of twists in the DNA ahead.[19] This build-up forms a torsional resistance that would eventually halt the progress of the replication fork. Topoisomerases are enzymes that temporarily break the strands of DNA, relieving the tension caused by unwinding the two strands of the DNA helix; topoisomerases (including DNA gyrase) achieve this by adding negative supercoils to the DNA helix.[20]

Bare single-stranded DNA tends to fold back on itself forming secondary structures; these structures can interfere with the movement of DNA polymerase. To prevent this, single-strand binding proteins bind to the DNA until a second strand is synthesized, preventing secondary structure formation.[21]

Clamp proteins form a sliding clamp around DNA, helping the DNA polymerase maintain contact with its template, thereby assisting with processivity. The inner face of the clamp enables DNA to be threaded through it. Once the polymerase reaches the end of the template or detects double-stranded DNA, the sliding clamp undergoes a conformational change that releases the DNA polymerase. Clamp-loading proteins are used to initially load the clamp, recognizing the junction between template and RNA primers.[2]:274-5

At the replication fork, many replication enzymes assemble on the DNA into a complex molecular machine called the replisome. The following is a list of major DNA replication enzymes that participate in the replisome:[22]

Replication machineries consist of factors involved in DNA replication and appearing on template ssDNAs. Replication machineries include primosotors are replication enzymes; DNA polymerase, DNA helicases, DNA clamps and DNA topoisomerases, and replication proteins; e.g. single-stranded DNA binding proteins (SSB). In the replication machineries these components coordinate. In most of the bacteria, all of the factors involved in DNA replication are located on replication forks and the complexes stay on the forks during DNA replication. These replication machineries are called replisomes or DNA replicase systems. These terms are generic terms for proteins located on replication forks. In eukaryotic and some bacterial cells the replisomes are not formed.

Since replication machineries do not move relatively to template DNAs such as factories, they are called a replication factory.[24] In an alternative figure, DNA factories are similar to projectors and DNAs are like as cinematic films passing constantly into the projectors. In the replication factory model, after both DNA helicases for leading strands and lagging strands are loaded on the template DNAs, the helicases run along the DNAs into each other. The helicases remain associated for the remainder of replication process. Peter Meister et al. observed directly replication sites in budding yeast by monitoring green fluorescent protein(GFP)-tagged DNA polymerases . They detected DNA replication of pairs of the tagged loci spaced apart symmetrically from a replication origin and found that the distance between the pairs decreased markedly by time.[25] This finding suggests that the mechanism of DNA replication goes with DNA factories. That is, couples of replication factories are loaded on replication origins and the factories associated with each other. Also, template DNAs move into the factories, which bring extrusion of the template ssDNAs and nascent DNAs. Meisters finding is the first direct evidence of replication factory model. Subsequent research has shown that DNA helicases form dimers in many eukaryotic cells and bacterial replication machineries stay in single intranuclear location during DNA synthesis.[24]

The replication factories perform disentanglement of sister chromatids. The disentanglement is essential for distributing the chromatids into daughter cells after DNA replication. Because sister chromatids after DNA replication hold each other by Cohesin rings, there is the only chance for the disentanglement in DNA replication. Fixing of replication machineries as replication factories can improve the success rate of DNA replication. If replication forks move freely in chromosomes, catenation of nuclei is aggravated and impedes mitotic segregation.[25]

Eukaryotes initiate DNA replication at multiple points in the chromosome, so replication forks meet and terminate at many points in the chromosome; these are not known to be regulated in any particular way. Because eukaryotes have linear chromosomes, DNA replication is unable to reach the very end of the chromosomes, but ends at the telomere region of repetitive DNA close to the ends. This shortens the telomere of the daughter DNA strand. Shortening of the telomeres is a normal process in somatic cells. As a result, cells can only divide a certain number of times before the DNA loss prevents further division. (This is known as the Hayflick limit.) Within the germ cell line, which passes DNA to the next generation, telomerase extends the repetitive sequences of the telomere region to prevent degradation. Telomerase can become mistakenly active in somatic cells, sometimes leading to cancer formation. Increased telomerase activity is one of the hallmarks of cancer.

Termination requires that the progress of the DNA replication fork must stop or be blocked. Termination at a specific locus, when it occurs, involves the interaction between two components: (1) a termination site sequence in the DNA, and (2) a protein which binds to this sequence to physically stop DNA replication. In various bacterial species, this is named the DNA replication terminus site-binding protein, or Ter protein.

Because bacteria have circular chromosomes, termination of replication occurs when the two replication forks meet each other on the opposite end of the parental chromosome. E. coli regulates this process through the use of termination sequences that, when bound by the Tus protein, enable only one direction of replication fork to pass through. As a result, the replication forks are constrained to always meet within the termination region of the chromosome.[26]

Within eukaryotes, DNA replication is controlled within the context of the cell cycle. As the cell grows and divides, it progresses through stages in the cell cycle; DNA replication takes place during the S phase (synthesis phase). The progress of the eukaryotic cell through the cycle is controlled by cell cycle checkpoints. Progression through checkpoints is controlled through complex interactions between various proteins, including cyclins and cyclin-dependent kinases.[27] Unlike bacteria, eukaryotic DNA replicates in the confines of the nucleus.[28]

The G1/S checkpoint (or restriction checkpoint) regulates whether eukaryotic cells enter the process of DNA replication and subsequent division. Cells that do not proceed through this checkpoint remain in the G0 stage and do not replicate their DNA.

Replication of chloroplast and mitochondrial genomes occurs independently of the cell cycle, through the process of D-loop replication.

In vertebrate cells, replication sites concentrate into positions called replication foci.[25] Replication sites can be detected by immunostaining daughter strands and replication enzymes and monitoring GFP-tagged replication factors. By these methods it is found that replication foci of varying size and positions appear in S phase of cell division and their number per nucleus is far smaller than the number of genomic replication forks.

P. Heun et al.(2001) tracked GFP-tagged replication foci in budding yeast cells and revealed that replication origins move constantly in G1 and S phase and the dynamics decreased significantly in S phase.[25] Traditionally, replication sites were fixed on spatial structure of chromosomes by nuclear matrix or lamins. The Heuns results denied the traditional concepts, budding yeasts don't have lamins, and support that replication origins self-assemble and form replication foci.

By firing of replication origins, controlled spatially and temporally, the formation of replication foci is regulated. D. A. Jackson et al.(1998) revealed that neighboring origins fire simultaneously in mammalian cells.[25] Spatial juxtaposition of replication sites brings clustering of replication forks. The clustering do rescue of stalled replication forks and favors normal progress of replication forks. Progress of replication forks is inhibited by many factors; collision with proteins or with complexes binding strongly on DNA, deficiency of dNTPs, nicks on template DNAs and so on. If replication forks stall and the remaining sequences from the stalled forks are not replicated, the daughter strands have nick obtained un-replicated sites. The un-replicated sites on one parent's strand hold the other strand together but not daughter strands. Therefore, the resulting sister chromatids cannot separate from each other and cannot divide into 2 daughter cells. When neighboring origins fire and a fork from one origin is stalled, fork from other origin access on an opposite direction of the stalled fork and duplicate the un-replicated sites. As other mechanism of the rescue there is application of dormant replication origins that excess origins don't fire in normal DNA replication.

Most bacteria do not go through a well-defined cell cycle but instead continuously copy their DNA; during rapid growth, this can result in the concurrent occurrence of multiple rounds of replication.[29] In E. coli, the best-characterized bacteria, DNA replication is regulated through several mechanisms, including: the hemimethylation and sequestering of the origin sequence, the ratio of adenosine triphosphate (ATP) to adenosine diphosphate (ADP), and the levels of protein DnaA. All these control the binding of initiator proteins to the origin sequences.

Because E. coli methylates GATC DNA sequences, DNA synthesis results in hemimethylated sequences. This hemimethylated DNA is recognized by the protein SeqA, which binds and sequesters the origin sequence; in addition, DnaA (required for initiation of replication) binds less well to hemimethylated DNA. As a result, newly replicated origins are prevented from immediately initiating another round of DNA replication.[30]

ATP builds up when the cell is in a rich medium, triggering DNA replication once the cell has reached a specific size. ATP competes with ADP to bind to DnaA, and the DnaA-ATP complex is able to initiate replication. A certain number of DnaA proteins are also required for DNA replication each time the origin is copied, the number of binding sites for DnaA doubles, requiring the synthesis of more DnaA to enable another initiation of replication.

Researchers commonly replicate DNA in vitro using the polymerase chain reaction (PCR). PCR uses a pair of primers to span a target region in template DNA, and then polymerizes partner strands in each direction from these primers using a thermostable DNA polymerase. Repeating this process through multiple cycles amplifies the targeted DNA region. At the start of each cycle, the mixture of template and primers is heated, separating the newly synthesized molecule and template. Then, as the mixture cools, both of these become templates for annealing of new primers, and the polymerase extends from these. As a result, the number of copies of the target region doubles each round, increasing exponentially.[31]

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DNA replication - Wikipedia

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