Despite alien attacks such as in "Lost City" and "Ex Deus Machina", all attempts are made throughout the series to keep the existence of the Stargate Program secret, assuming there would be mass panic if the public found out. Several alternate-universe episodes address the public reaction to the revelation of the Stargate Program. Nevertheless, some conspiracy theorists in the series assume extraterrestrial activity at the highest levels of the military. A very few select civilians such as Martin Lloyd and Jeannie Miller are also aware of the existence of the Program.
The Stargate SG-1 premiere reveals the existence of another grave extra-terrestrial threat to Earth, Apophis, and that there are in fact thousands of planets accessible through the Stargate. As a result, the United States establishes Stargate Command inside Cheyenne Mountain and commissions nine teams (which increases to many more in the later seasons) to travel through the Gate to assess threats, open negotiations with other civilizations, and procure technology to defend Earth. The first SG mission to Apophis' homeworld, Chulak, sees the defection of Jaffa warrior Teal'c to Earth. In the early seasons of Stargate SG-1, SG teams from Earth fights battles against Apophis and the rest of Goa'uld the System Lords. Along the way, they make offworld allies including the Tok'ra and the Asgard,, support a growing rebellion amongst the Jaffa, and encounter a dangerous new threat from another galaxy, the mechanical Replicators. The Stargate Program also endures challenges from its own government; the ambitious Senator Robert Kinsey seeks to shut down and later control the SGC, and the activities of the unscrupulous N.I.D. threatens to destabilize Earth's offworld relations.
Season eight of Stargate SG-1 sees the final defeat of the System Lords and the Replicators, changing the political face of the galaxy. Dr. Daniel Jackson also discovers the address for the Ancients' Lost City of Atlantis in the Pegasus galaxy, and the international Atlantis Expedition is formed. In Pegasus Earth discovers more enemies, including the life-consuming Wraith and the nanite Asurans. A new enemy, the Ori, is introduced in the ninth season of SG-1. Their story arc is concluded in Stargate: The Ark of Truth with the defeat of the last Ori, the Ascended being Adria, and the turning of her armies.
The SGC base, where most episodes of SG-1 begin and end, is the main setting in Stargate SG-1 and occasionally features on Stargate Atlantis. Half a dozen stock shots of Cheyenne Mountain were filmed at the beginning of the series and re-used until season 8, but the producers did not decide until the beginning of season 9 to film new shots, thinking that Stargate SG-1 would be cancelled after each current year. The interior of the SGC base, together with the Atlantis set, is filmed at stages 5 and 6 at The Bridge Studios in Vancouver, Canada. As of August 2008, the SGC set is still standing to allow for future films.
Like the real Cheyenne Mountain Air Force Station, the SGC extends many levels beneath the ground (officially called sub-levels), thus protecting the base from most forms of attack including indirect nuclear detonations. In the Stargate universe, the base also serves to contain biological, chemical or alien hazards to the outside world by means of a 'lockdown' status. The briefing room and the SGC Commander's office is located at level 27, while the Gate Room with the Stargate and an elevated Control Room are at level 28. A long ramp in the middle of the Gateroom leading up to the Stargate allows vehicles (such as the MALP robot probe) to enter the Stargate. The Stargate may be lifted in and out through a ceiling that can open. The real Cheyenne Mountain Air Force Station denies fan theories of the existance of a Stargate in their Command Center.
The Stargate is equipped with a metallic barrier called the Iris to prevent hostile aliens from entering the SGC. Off-world SG teams additionally carry a GDO to identify themselves to the SGC. If nevertheless faced with an alien invasion, the facility has a self-destruct mechanism, which has been activated on more than one occation on the show. According to Col. Carter, the self-destruct is not powerful enough to destroy the Stargate or to disconnect an active wormhole, but it would bury the gate under 1000 meters of rock to stop incoming travelers.
The SGC base is typically commanded by a General and is staffed by subject matter experts and military support personnel, several elite special operations teams, and several SG teams, including SG-1. These offworld teams usually operate as teams of four, although that is not a requirement. The first leader of the SGC is Major General West in the film, followed by Major General George Hammond from season 1 through 7. Major General Bauer briefly replaces Hammond, who retires under duress in season 5's "Chain Reaction". Dr. Elizabeth Weir becomes the first civilian commander of the SGC after Hammond's reassignment in season 7's "Lost City". When Weir leaves the SGC in season 8's "New Order" to be in charge of the Atlantis Expedition early in Season 8, Brigadier General Jack O'Neill takes over for season 8 until he replaces Hammond as the commander of the Department of Homeworld Security in early season 9. Major General Hank Landry is leader of the SGC in seasons 9 and 10 and the two direct-to-DVD SG-1 films.
Although the Alpha Site is mentioned early on in Stargate SG-1, the first Alpha Site is only shown in the season 6 episode "Allegiance". In the story located on a planet designed P3X-984 that is unknown to the Goa'uld, this Alpha Site was shot in a gravel pit at Mount Seymour in North Vancouver. The set designers used a number of sets from season 4's "Prodigy" for the façade and filled the remaining gaps with the set decorator and transportation tents. After Anubis probes Jonas Quinn's mind in season 7's "Fallen" and learns of the first Alpha Site, a second Alpha site is built. Some months after its establishment, it falls under attack by several Kull Warriors in season 7's "Death Knell" and is abandoned. Peter DeLuise came up with this story idea when much wood was cut down in the Greater Vancouver Regional District (where outside locations of Stargate SG-1 were often filmed), looking like after an explosion. The third Alpha Site, on a planet designated P4X-650, is built inside a mountain and has a runway for the F-302. RepliCarter visits this facility in "Gemini", as part of a ruse to rid herself of Fifth and learn more about the Ancient Replicator disruptor.
Season 7's "Death Knell" shows a Beta Site on an unknown planet as a back-up facility operated by the SGC. Other Beta sites are mentioned in alternate realities – one equivalent to the Alpha Site in season 1's "There But For the Grace of God", and another is mentioned in season 3's "Point of View". A Gamma Site is shown in season 9's "The Scourge" as a research outpost established on a planet with unique radioactive ionosphere 24,000 light years from Earth. The base has several F-302's attached to it. At any given time more than 30 scientists conduct research in several fields including biology, botany, entomology and physics. After the auto-destruct of this Gamma Site, a new Gamma Site relays a message in "The Pegasus Project".
Throughout the run of Stargate SG-1, the work of the Rogue NID is associated with Colonel Harry Maybourne. The group initially uses the second Stargate unearthed in "Solitudes", and later bases their operations off-world or in disused warehouses throughout the Earth. The rogue elements justify their unscrupulous methods as defense from the Goa'uld attack on Earth regardless of considerations like inter-planetary diplomacy, criticising the diplomatic contacts and negotiations of the SGC as too slow. The leading shadow group of the rogue NID, "The Committee", are made up of various individual businessmen, politicians and corporations who wish to exploit alien technology for financial gain. The more prominent members of the rogue NID are later revealed to be Senator Robert Kinsey and Colonel Frank Simmons. The SGC puts an end to the rogue NID in "Smoke and Mirrors" after arresting and imprisoning the majority of its upper echelon.
The Trust is a shady interplanetary terrorist group composed of rogue ex-NID operatives and the international business and political cabal which funds them. The Trust is more radical in their methods and objectives than the Rogue NID, coming into direct conflict with the SGC and the U.S. Air Force several times. When the producers came up story ideas with this group, they found that Alias had used all the names they could think of. It was not until several weeks after they had decided on the name "Trust" that they found out that Alias had used that name as well. Faced with the choice to either go with the Trust or with what Joseph Mallozzi called "The Former Rogue Elements of the N.I.D. Now Working for Private Interests Bent on Global Domination", they chose the first option.
After Vice President Kinsey still shows his strong ties to the rogue ex-NID agents in season 7's "Inauguration" and is subsequently forced into resigning, the SGC learns the name "the Trust" in season 8's "Covenant". The Trust use a Goa'uld ship in "Endgame" to launch an all-out attack on the Goa'uld with symbiote poison, without regard to Jaffa or Tok'ra life. Season 8's "Full Alert" reveals that the Goa'uld have successfully infiltrated and captured some of Trust members, providing an immediate power base for the Goa'uld; Ba'al has taken control of the Trust by "Ex Deus Machina". The Trust last appears in Stargate SG-1 in season 10's "Memento Mori", capturing Vala to find an infinite treasure, but they also appear in the Stargate Atlantis season 2 episode "Critical Mass", planting an explosive device in the City of Atlantis.
After the defeat of Anubis's Fleet and the subsequent discovery of the Ancient outpost in Antarctica, an international committee is established to oversee it and the Atlantis expedition. The five permanent members of the UN Security Council and the signatory members of the Antarctic Treaty (including Jamaica, Philippines, Portugal, Croatia and Spain) sign the Gate Alliance Treaty, which specifies that all acquired alien technology will be shared between the member nations, in exchange for assistance in keeping the program secret. However, in the following three years, the US military interprets the treaty to only apply to non-military technology, which the Chinese delegate mentions as a sore point. Still, not all nations have been informed about the existence of the Stargate.
The most prominent IOA member is Richard Woolsey as a US representative. Two other American IOA members are James Merek (Currie Graham), shown in Stargate: The Ark of Truth, and Coolidge (Rob LaBelle), shown in "Midway". Representatives of other nations are shown in season 9's "The Scourge" – Russel Chapman of the United Kingdom (played by Andy Maton), Jean Lapierre of France (Mark Oliver), Chen Xiaoyi of China (Tamlyn Tomita), and Col. Chekov of Russia (Gary Chalk). When these representatives review operations at the SGC and Atlantis, members of both the SGC and the Atlantis expedition display a rather low opinion of the IOA. According to Dr. Elizabeth Weir in "No Man's Land", the IOA's inability to make final decisions is only a strategic maneuver to not take responsibility, therefore having a scapegoat (such as Weir herself) in case things go wrong.
Changes in [gamma]-secretase activity and specificity caused by the introduction of consensus aspartyl protease active motif in Presenilin 1.(Research article)
May 12, 2008; Authors: Donald B Carter ; Edwige Dunn ; Adele M Pauley ; Denise D McKinley ; Timothy J Fleck ; Brenda R...