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After a disappointing showing at Monza a controversial denial of championship points from a Mirage win at the Spa event, Ford saw limited opportunity for taking the Manufacturers' title again and instead concentrated on a last hurrah at Le Mans, where the leading Mark IV, driven by Dan Gurney and A.J. Foyt, won handily. Ferrari took the Manufacturers' title for 1967, edging up-and-coming Porsche by two points. The Ford-Ferrari War was ended by new rules for 1968 that eliminated the P4s and Mark IVs from eligibility for the Sports Prototype class with a 3-litre engine capacity limit. The GT40s met the production requirement and 5 litre limit for homologation in the new Group 4 class. |
Ferrari found the production requirement for homologating the P4 under Group 4 daunting and withdrew from competition in the sport-racer classes. Neither Ford nor Ferrari fielded a factory team for the Manufacturers' Championship that year; however, the John Wyer team running the Group 4 GT40s brought home the title for Ford and in 1969 achieved wins with the GT40 at Sebring and Le Mans. When Ferrari was able to enter a homologated car for 1970, the class they competed in was dominated by the Porsche 917. Several cars of the original 24-hours race have survived and have been restored to their former glory. |
The crowd-pleasing Mini Marcos was club raced, rallied and hill climbed, road registered twice and repainted five times only to be stolen in the night of 30 October 1975 from beneath a flat in Paris. Three days earlier Marcos-boss Harold Dermott had made a deal to buy the car with the intention to restore it and put on museum display. Several people searched for the car ever since, but it was only found back in December 2016 in Portugal by Dutchman Jeroen Booij. Legacy in popular culture Go Like Hell The race became the subject of a 2009 book, detailing the race and the famous background rivalry between Enzo Ferrari and Henry Ford II, by A.J. |
Baime titled "Go Like Hell"—the words shouted by Bruce McLaren to Chris Amon as they drove to their famous victory. Chris Amon was interviewed in 2016: Rumors of a movie adaptation of the book, an Amazon best seller, circulated from 2013 to 2015. The book attained a "4.5 star" rating by book review website GoodReads.com. The 24 Hour War A 2016 documentary film, produced and directed by Americans Nate Adams and comedian Adam Carolla, features the Le Mans rivalry between Ferrari and Ford. The production was well received critically, attaining a "100%" rating on review aggregate website Rotten Tomatoes. Ford v Ferrari Ford v Ferrari (known as Le Mans '66 in the UK and other territories) is a sports drama film distributed by 20th Century Fox, based on the rivalry between Ford and Ferrari for dominance at Le Mans. |
Directed by James Mangold, starring Matt Damon and Christian Bale in the roles of Carroll Shelby and Ken Miles, respectively. The film was released on November 15, 2019. At the 92nd Academy Awards, the film received four nominations, including Best Picture and Best Sound Mixing, and won for Best Sound Editing and Best Film Editing. Official results Finishers Results taken from Quentin Spurring's book, officially licensed by the ACO Class Winners are in Bold text. Did not finish Did not start Class winners Note: setting a new Distance Record. Index of thermal efficiency Note: Only the top ten positions are included in this set of standings. |
Index of performance Taken from Moity's book. Note: Only the top ten positions are included in this set of standings. A score of 1.00 means meeting the minimum distance for the car, and a higher score is exceeding the nominal target distance. |
Statistics Taken from Quentin Spurring's book, officially licensed by the ACO Fastest Lap in practice – D.Gurney, #3 Ford GT40 Mk II – 3:30.6secs; Fastest Lap – D.Gurney, #3 Ford GT40 Mk II – 3:30.6secs; Distance – Winner's Average Speed – Attendance – 350 000 Challenge Mondial de Vitesse et Endurance standings As calculated after Le Mans, Round 4 of 4 Citations References Armstrong, Douglas, English editor (1967) Automobile Year #14 1966–67 Lausanne: Edita S.A. Clarke, R.M., editor (1997) Le Mans 'The Ford and Matra Years 1966–1974' Cobham, Surrey: Brooklands Books Clausager, Anders (1982) Le Mans London: Arthur Barker Ltd Fox, Charles (1973) The Great Racing Cars & Drivers London: Octopus Books Ltd Laban, Brian (2001) Le Mans 24 Hours London: Virgin Books Moity, Christian (1974) The Le Mans 24 Hour Race 1949–1973 Radnor, Pennsylvania: Chilton Book Co Spurring, Quentin (2010) Le Mans 1960–69 Yeovil, Somerset: Haynes Publishing External links Racing Sports Cars – Le Mans 24 Hours 1966 entries, results, technical detail. |
Retrieved 20 March 2018 Le Mans History – Le Mans History, hour-by-hour (incl. pictures, YouTube links). Retrieved 20 March 2018 World Sports Racing Prototypes – results, reserve entries & chassis numbers. Retrieved 20 March 2018 Team Dan – results & reserve entries, explaining driver listings. Retrieved 20 March 2018 Unique Cars & Parts – results & reserve entries. Retrieved 20 March 2018 Formula 2 – Le Mans results & reserve entries. Retrieved 20 March 2018 YouTube "This Time Tomorrow" – Colour film by Ford about their race (30mins). Retrieved 8 April 2018 YouTube "Eight Metres" – Colour film about the race & the finish (30mins). |
Retrieved 8 April 2018 YouTube – Colour film about the start & the finish (5mins). Retrieved 8 April 2018 YouTube – Silent b/w footage including start (2mins). Retrieved 8 April 2018 YouTube "British Pathé" – Silent b/w footage including start (2mins). Retrieved 8 April 2018 YouTube – modern footage interviewing the pit crew of Ford #1 (5mins). Retrieved 8 April 2018 Category:24 Hours of Le Mans races Le Mans Category:1966 in French motorsport |
The three-toed sloths are arboreal neotropical mammals (also known as "three-fingered" sloths). They are the only members of the genus Bradypus and the family Bradypodidae. The four living species of three-toed sloths are the brown-throated sloth, the maned sloth, the pale-throated sloth, and the pygmy three-toed sloth. In complete contrast to past morphological studies, which tended to place Bradypus as the sister group to all other folivorans, molecular studies place them nested within the sloth superfamily Megatherioidea, making them the only surviving members of that radiation. Extant species Evolution A study of mitochondrial cytochrome b and 16S rRNA sequences suggests that B. torquatus diverged from B. variegatus and B. tridactylus about 12 million years ago, while the latter two split 5 to 6 million years ago. |
The diversification of B. variegatus lineages was estimated to have started 4 to 5 million years ago. Relation to the two-toed sloth Both types of sloth tend to occupy the same forests; in most areas, a particular species of three-toed sloth and a single species of the somewhat larger and generally faster-moving two-toed sloth will jointly predominate. Although similar in overall appearance, the two genera are placed in different families. Recent phylogenetic analyses support the morphological data from the 1970s and 1980s that the two genera are not closely related and that each adopted their arboreal lifestyles independently. From morphological studies it was unclear from which ground-dwelling sloth taxa the three-toed sloths evolved or whether they retained their arboreality from the last common ancestor of extant sloths. |
The two-toed sloths were thought on the basis of morphology to nest phylogenetically within one of the divisions of ground-dwelling Caribbean sloths. Our understanding of sloth phylogeny has recently been greatly revised by molecular studies, based on collagen and mitochondrial DNA sequences. These investigations consistently place three-toed sloths within Megatherioidea, close to Megalonyx, megatheriids and nothrotheriids, and two-toed sloths close to mylodontids, while moving the Caribbean sloths to a separate, basal branch of the sloth evolutionary tree. These results provide further strong support for the long-held belief that arboreality arose separately in the two genera via convergent paths. Characteristics Famously slow-moving, a sloth travels at an average speed of . |
Three-toed sloths are about the size of a small dog or a large cat, with the head and body having a combined length around and a weight of . Unlike the two-toed sloths, they also have short tails of , and they have three clawed toes on each limb. All sloths have three digits on their hindlimbs; the difference is found in the number of digits on the forelimbs; thus they are sometimes referred to as three-fingered sloths. However, sloths are generally regarded as quadrupeds. Behavior Unlike the two-toed sloth, three-toed sloths are agile swimmers. They are still slow in trees. |
The muscles that sloths use to grip and produce a pulling motion are much more prominent than those that produce a pushing motion. This means that they struggle to support their body weight when walking on all four limbs, so travelling on the ground is a dangerous and laborious process. Three-toed sloths are arboreal (tree-dwelling), with a body adapted to hang by their limbs. Large, curved claws and muscles specifically adapted for strength and stamina help sloths to keep a strong grip on tree branches. The abdominal organs close to their diaphragm (such as their stomach, liver and kidneys) are attached to their lower ribs (or pelvic girdle in the latter case) by fibrinous adhesions, which prevent the weight of these organs from compressing their lungs when hanging, making inhalation easier. |
They live high in the canopy, but descend once a week to defecate on the forest floor. During this week-long interval their feces and urine accumulate to about a third of their total body mass. It takes about a month for a single leaf to pass through their four-chambered stomach and digestive tract. Although they get most of their fluids from the leaves that they eat, they have been observed drinking directly from rivers. Because of their slow metabolism, they do not need to ingest many leaves on a daily basis; however, when ambient temperatures are high, the symbiotic microbes and bacteria present in their gut will break down and ferment food at a faster rate. |
Conversely, when temperatures are lower, sloths will consume less, which is opposite to what has been observed in most other mammals. Their long, coarse fur often appears greenish, not due to pigment, but to algae growing on it. Sloths' greenish color and their sluggish habits provide an effective camouflage; hanging quietly, sloths resemble a bundle of leaves. They move between different trees up to four times a day, although they prefer to keep to a particular type of tree, which varies between individuals, perhaps as a means of allowing multiple sloths to occupy overlapping home ranges without competing with each other. |
Three-toed sloths are predominantly diurnal, although they can be active at any hour of the day, while two-toed sloths are nocturnal. Lifecycle Members of this genus tend to live around 25 to 30 years, reaching sexual maturation at three to five years of age. Three-toed sloths do not have a mating season and breed year round. Females give birth to a single young after a gestation period around six months. The offspring cling to their mother's bellies for around nine months. They are weaned around nine months of age, when the mother leaves her home territory to her offspring and moves elsewhere. |
Adults are solitary, and mark their territories using anal scent glands and dung middens. Male three-toed sloths are attracted to females in estrus by their screams echoing throughout the canopy. Sloth copulation lasts an average of 25 minutes. Male three-toed sloths are strongly polygamous, and exclude competitors from their territory. Males are also able to compete with one another within small habitable territories. The home ranges used by wild brown-throated three-toed sloths in Costa Rica include cacao, pasture, riparian forests, peri-urban areas and living fence-rows. For the first few months after giving birth, mothers remain at just one or two trees, and guide their young. |
At about five to seven months of age, when the young have become more independent, mothers expand their resources and leave their young in new areas. During natal dispersion, three-toed sloths prefer tropical forests, often using riparian forest habitat to disperse. The home range for mothers are larger than those of young. After separation, only the mothers use the cacao agro forest, but both use riparian forest. Different types of trees are used by both mother and young, which indicates that this agricultural matrix provides an important habitat type for these animals. Dentition and skeleton Three-toed sloths have no incisor or canine teeth, just a set of peg-shaped cheek teeth that are not clearly divided into premolars and molars, and lack homology with those teeth in other mammals, thus are referred to as molariforms. |
The molariform dentition in three-toed sloths is simple and can be characterized as dental formula of: . Three-toed sloths are unusual amongst the mammals in possessing as many as nine cervical vertebrae, which may be due to mutations in the homeotic genes. All other mammals have seven cervical vertebrae, other than the two-toed sloth and the manatee, which have only six. References External links "Three-toed sloth." Passport to Knowledge. 21 Feb. 2009 Category:Sloths Category:Mammals described in 1758 Category:Taxa named by Carl Linnaeus |
Ada Health GmbH is a company based in Berlin which produces Ada, a symptom checker app. It was founded by Claire Novorol, a British pediatrician, Martin Hirsch and Daniel Nathrath. Nathrath is a graduate of the University of Houston Law Center. The company has raised $69.3 million since it was founded in 2011. The app started out as a platform service for doctors and was adapted in 2016 to focus on the bits patients could understand. The app takes reported symptoms, matches them with symptoms of patients of similar age and gender, and reports the statistical likelihood that the patient has a certain condition. |
The detailed report, compiled by Ada, can be sent to a doctor as a PDF. The app is available in English, German, Spanish and Portuguese. In September 2018 it had been downloaded about five million times. It is free of charge and has the highest consumer ranks among similar apps. It is to be made available in Swahili and in Romanian thanks to funding from the Bill & Melinda Gates Foundation and Fondation Botnar. Ada has been compared to WebMD, Babylon's GP at Hand app and Your.MD. In October 2017, when three apps were tested with symptoms from asthma, shingles, alcohol-related liver disease, and urinary tract infection, Ada performed very well; it asked about the most important symptoms and provided the best diagnoses. |
It produced diagrams showing which of the symptoms for each disease were present and the strength of the link, and a diagram of the percentage of people likely to have that diagnosis. Future plans include customizing the software to collect data on the prevalence of diseases, like malaria, which may help to prevent epidemics. In October 2019 a German IT security professional claimed that the Ada app was sending sensitive user-data (f.e. symptoms, IPs, Android ad IDs etc) to the Amplitude product analytics service (api.amplitude.com), and some German users' insurance provider to their Facebook Analytics account. References Category:2011 establishments in Germany Category:Medical technology companies of Germany Category:Companies based in Berlin Category:Health information technology companies Category:Private providers of NHS services |
The Albert R. Broccoli 007 Stage is one of the largest sound stages in the world. It is located at Pinewood Studios, Iver Heath, Buckinghamshire, England, and named after James Bond film producer Albert R. "Cubby" Broccoli. The stage was originally conceived in 1976 by production designer Ken Adam to house the set he had designed for the interior of the Liparus supertanker in the James Bond film The Spy Who Loved Me. The stage's construction cost $1.8 million. The stage was christened the "007 Stage" on 5 December 1976 during a ceremony attended by former British Prime Minister Harold Wilson. |
In contrast to the volcano crater set Adam had built for You Only Live Twice in 1966, the 007 Stage was to be a permanent structure that could be rented out to other productions. The 1976 stage measured 102 m by 41 m (334 ft by 136 ft) and was 12.5 m (40 ft 6 in) high. It had a maximum 4,220 m2 (45,424 sq ft) floor space. The stage featured a tank measuring 91 m by 22.5 m by 2.7 m (297 ft by 73 ft by 8 ft 10 in). According to 007stage.com, the water tank was an existing studio feature and the stage was created by constructing a building to completely enclose the tank. |
Technically, because it had no soundproofing, it was a "silent stage", the largest ever built. The 007 Stage burnt to the ground on 27 June 1984 towards the end of filming of Ridley Scott's Legend. It was rebuilt, and reopened in January 1985, with the new name, "Albert R. Broccoli 007 Stage", in time for filming to commence on A View to a Kill (1985). Another fire occurred on 30 July 2006. The fire occurred just after production ended on the Bond film Casino Royale while the Venetian piazza set was being dismantled. Eight fire engines took 90 minutes to bring the fire under control; a spokesman for the local fire brigade said gas canisters may have exploded inside the building. |
Filming had been completed on the stage several days before and it was being dismantled, so it did not delay production or release of the film. The damage to the building was extensive, causing the roof of the building to collapse. On 31 July 2006, Pinewood issued a statement indicating that the stage "will need to be demolished and rebuilt" and that there had been no casualties in the incident. The fire-damaged stage was demolished on 13–14 September. Construction on the new stage began on 18 September and was completed in under six months. The new stage was redesigned and included a number of new features including an increased working floor space area, enclosed stairwells to the gantry, a vehicle ramp into the tank, aircraft hangar-style loading doors, increased electrical power and better insulation. |
The new stage is 374 ft long, 158 ft wide, and 41–50 ft high (114 × 48 × 12–15 m). The stage is the biggest in Europe at around . An explosion shot in the sound stage on 4 June 2019 caused extensive damage to the external wall of the stage. |
Filmed in the 007 stage The Spy Who Loved Me (1977): The Liparus supertanker Superman: The Movie (1978) and Superman II (1980): Arctic ice floe and exterior entrance to Fortress of Solitude Moonraker (1979): Cable car closeups/Special effects model work for the space battle Superman II (1980): giant model of Metropolis streets and buildings Clash of the Titans (1981): Lair of the Stygian Witches and travelling matte work Dragonslayer (1981): exterior of dragon's lair; set built above tank so dragon could burst through the ground For Your Eyes Only (1981): The underwater wreck of the St. Georges Krull (1983): Swamp Octopussy (1983): Hangar explosion/Monsoon Palace courtyard and helipad for a JetRanger helicopter; helipad later removed from the "giant set" and rebuilt outside for landing and takeoff scenes of the Aérospatiale SA 360 Dauphin scenes. |
helicopter Superman III (1983): Supercomputer cave Legend (1984): Forest scene Arena (1985): Concert film and the video for "The Wild Boys" by Duran Duran Santa Claus: The Movie (1985): Santa's workshop A View to a Kill (1985): Zorin's silicon mine, scenes of flooding Little Shop of Horrors (1986): Skid Row set Batman (1989): The Batcave Alien 3 (1992): Blast furnace Interview with the Vampire (1994): Theatre of the Vampires Mary Reilly (1996) Mission: Impossible (1996): Full-size TGV model filmed against green screen for Channel Tunnel chase sequence Event Horizon (1997): "Second Containment area" and passageway with globe and rotating spikes The Fifth Element (1997): Interior of spaceship, scene of the big shootout Tomorrow Never Dies (1997): Interior of Elliot Carver's stealth boat; also, the HMS Devonshire underwater set The Avengers (1998): Sir August de Wynter's weather machine Still Crazy (1998): Indoor concert Joseph and the Amazing Technicolor Dreamcoat: Pharaoh scenes with big Sphinx head The World Is Not Enough (1999): Russian nuclear testing facility Lara Croft: Tomb Raider (2001): Stage divided into two: First tomb built on one side, second tomb built on the other side Die Another Day (2002): Gustav Graves' Ice Palace Lara Croft: Tomb Raider – The Cradle of Life (2003): Stage divided into two: Greek temple built on one side, African caves on the other side Alexander (2004): Babylon Palace on one side, Indian Palace on the other side Charlie and the Chocolate Factory (2005): The chocolate room with chocolate river The Da Vinci Code (2006): The Louvre gallery Casino Royale (2006): Venice piazza and interior of sinking hotel. |
Mamma Mia! |
(2008): Greek fishing village Quantum of Solace (2008): Sienese art gallery; cisterns and MI6 safehouse; sink hole; hotel elevator; three levels of walkways and staircases for ECO hotel Prince of Persia: The Sands of Time (2010): Alamut castle Harry Potter and the Deathly Hallows – Part 1 (2010): The frozen lake Pirates of the Caribbean: On Stranger Tides (2011): the Fountain of Youth Harry Potter and the Deathly Hallows – Part 2 (2011): The Dark Forest Intel Ultrabook: Egypt Commercial (2012): New York street and Egyptian street Prometheus (2012): Pyramid entrance, tunnels, and ampule chamber with giant statue head; set was so big that the 007 Stage had an annex added to its north side to accommodate 150 foot sloping incline towards entrance; ampule chamber later revamped to become pilot chamber with "jockey chair" Skyfall (2012): MI6's underground headquarters; Shanghai skyscraper atrium and offices with working elevator; underground platform; tunnels; and train crash Last Passenger (2013): Three days of pick-up shots. |
Jack Ryan: Shadow Recruit (2013): Water-filled "Wall Street vent facility." Maleficent (2014) Cinderella (2015): Ballroom; Cinderella's attic Everest (2015): Mountainous crags constructed using styrofoam and chips of soap/potato as snow, backed by huge green screens Spectre (2015): M's office and corridor; Palazzo Cadenza hall interior; full-scale replica of Westminster Bridge, laid with real tarmac, for full-scale helicopter crash and subsequent scenes. Assassin's Creed (2016): United Nations set; Abstergo complex including patient's room, hallway, recreation area, corridor and security room with exposed walls that make it look like it's built within an old Spanish church Emmerdale (2016), scenes of Aaron Dingle and Robert Sugden’s car submerged in water. |
Star Wars: The Last Jedi (2017): Canto Bight casino Solo: A Star Wars Story (2018): Corellian spaceport; Mimban trenches. No Time to Die (2020): Mock-up of research laboratory Porton Down. Controlled explosion resulted in partial damage to stage and injury of crew member outside stage Contrary to some sources (including IMDb), The Living Daylights did not film on the 007 Stage except for a music video by A-ha. Reports that parts of Supergirl were filmed on the 007 stage are not true. The Sulaco cargo bay set for Aliens was built on D stage. References External links Official page on 007 Stage The Pinewood Studios Group Pinewood Studios 007 Stage 007 Stage Category:British film studios Category:Buildings and structures in Buckinghamshire |
Creature Shock is a 1994 sci-fi first-person shooter game released on the PC and 3DO. The game was developed by Argonaut Games and published by Virgin Interactive. The game was later ported to the Philips CD-i, Sega Saturn and PlayStation video game systems. The title was one of the first extensive CD-ROM titles and used full-motion video for both cutscene and interactive portions. As a result, the game spans over a gigabyte in size and over two discs. Gameplay is divided into two portions: an on-rails shoot 'em up portion in which the player pilots a ship through various pre-rendered environments and an adventure-style first-person action portion where players chose between track-based paths at various nodes. |
Plot In 2123, the UNS Amazon is sent as part of an exploration fleet to various planets to determine new viable locations for settlement as the Earth is destroyed by human activity. En route to Saturn, the Amazon is ensnared by a massive alien being resembling a large asteroid. The protagonist, Commander Jason Barr, is sent to investigate the incident. He encounters heavy resistance on his way to Saturn, and after fighting through multitudes of alien ships, encounters the UNS Amazon almost completely absorbed by the organic asteroid. As he explores it, he comes into contact with what appears to be Captain Sumoki of the Amazon. |
However, she morphs into a demonic looking alien and attacks. Upon defeat, it reverts to the appearance of the Captain and Barr takes it back to the Moon base. The being is examined and determined to be an alien clone. Upon interrogation, it reveals an alien listening base located on Tethys. Barr heads to Tethys to find the base and destroy its communication uplink. Upon his arrival he encounters a probe which proceeds to scan his ship before heading back to the base. Barr chases it through the valleys, where he locates the base. He manages to complete his mission and escape the base before it's destroyed. |
His ship, however, gets caught in the data beam and he is pulled up through it. Regaining consciousness, he pilots the ship through several pieces of debris and destroys an awaiting alien ship. His ship is badly damaged in the process and crashes into the alien mothership. With no means of escape, he searches the ship and engages the leader in battle, finally defeating him on the bridge. He then accidentally activates the ship terraforming ability, changing its coordinates from Earth to Mars. With this Mars is transformed into a second Earth, providing humanity a new home. Version differences The PC and CD-i versions feature mouse support, and the CD-i version also supports the use of the CD-i light gun. |
All other versions of the game are compatible with standard controllers only. The PC and 3DO versions include three FMV exploration levels and two rail shooter levels. The CD-i and PlayStation versions and the Japanese release of the Saturn version contain only the three FMV exploration levels. Two versions were released for the Saturn: the Japanese release, which is similar to the PlayStation version, and the North American release, which is labeled as a "Special Edition". The Special Edition features slightly enhanced visuals and some options which do not appear in other versions of the game, but its main feature is two exclusive rail shooter levels with polygon graphics. |
These levels appear in the place of the PC version's two rail shooter levels, but bear no resemblance to them. They have a number of glitches; for instance, level 3 sometimes fails to end when the boss is defeated. Presumably due to space limitations, the Special Edition splits the final level into two levels, one on each disc. Sound disappears at set intervals during cutscenes in both Saturn versions. Ports In March 1994, Argonaut Software was signed as a third-party developer by Atari Corporation to develop games for the Atari Jaguar platform. A port of Creature Shock for the Atari Jaguar CD was announced at Spring ECTS '94 and SCES '94 as one of the first upcoming titles for the add-on and was also planned to be published by Virgin Interactive. |
The port was first showcased at E3 1995 and was slated for an August/Q3 1995 release, but development on the port was cancelled after the poor reception of a video demo showcased at Autumn ECTS '95 and several delays. Reception While hailed for its elaborate and beautiful artwork, the gameplay was razed. IGN stated in their 2 out of 10 review, "track-based shooters with lots of prerendered cut-shots are the bane of our existence. Woe to the hapless gamer who actually pays his hard earned money for these dogs. I warn you now: avoid Creature Shock like your life depends on it". |
A reviewer for Next Generation deemed Creature Shock "positive proof that a good game must consist of more than just flashy graphics and loud sound effects." He judged the game's limited level of interactivity to be utterly backwards, pointing out that the gameplay resembles the 1987 game After Burner. GamePros Captain Squideo gave the 3DO version a negative review, saying that despite the variety of gameplay styles, the gameplay feels routine due to the lack of multiple weapons. He also criticized that the cursor moves too slowly to keep up with enemies even when the player's technique is flawless. Reviewing the Saturn "Special Edition", Scary Larry called it "a poor man's Cyberia", saying that the game has imaginative visuals but grainy full motion video, a cursor that tends to get lost in the graphics, and a general lack of excitement and fun. |
A Next Generation critic said in a brief review that it "features great rendered graphics but drags with a low grade, point-and-click shooting interface." Notes References External links Creature Shock at GameFAQs Creature Shock at Giant Bomb Creature Shock at MobyGames Category:1994 video games Category:3DO Interactive Multiplayer games Category:Argonaut Games games Category:Cancelled Atari Jaguar games Category:CD-i games Category:DOS games Category:First-person shooters Category:Full motion video based games Category:PlayStation (console) games Category:Rail shooters Category:Sega Saturn games Category:Science fiction video games Category:Single-player video games Category:Video games developed in the United Kingdom |
Additive may refer to: Science Additive color, as opposed to subtractive color Additive function, a function in number theory Additive map, a function that preserves the addition operation Additive set-function – see Sigma additivity Additive inverse, an arithmetic concept Additive category, a preadditive category with finite biproducts Additive model, a statistical regression model Additive synthesis, an audio synthesis technique Additivity, in biochemistry, the simple sum of effects due to multiple causes – see Interaction § Biochemistry Additive genetic effects Engineering Feed additive Gasoline additive, a substance used to improve the performance of a fuel, lower emissions or clean the engine Oil additive, a substance used to improve the performance of a lubricant Weakly additive, the quality of preferences in some logistics problems Polymer additive Pit additive, a material aiming to reduce fecal sludge build-up and control odor in pit latrines, septic tanks and wastewater treatment plants Biodegradable additives Other uses Food additive, any substance added to food to improve flavor, appearance, shelf life, etc. |
Additive rhythm, a larger period of time constructed from smaller ones |
The 1991 Census of India was the 13th in a series of censuses held in India every decade since 1872. The population of India was counted as 838,583,988. The number of enumerators was 1.6 million. Religious demographics Hindus comprises 69.01 crore(81.53%) and Muslims were 10.67 crore(12.61%) in 1991 census. Population trends for major religious groups in India (1991) Language data The 1991 census recognizes 1,576 classified "mother tongues". According to the 1991 census, 22 'languages' had more than a million native speakers, 50 had more than 100,000 and 114 had more than 10,000 native speakers. The remaining accounted for a total of 566,000 native speakers (out of a total of 838 million Indians in 1991). |
The number of Sanskrit speakers in India in 1991 census was 49,736. Other statistics Census towns in 1991 census of India were 1,702. Jammu and Kashmir was excluded from Census-taking in 1991 due to Insurgency in Jammu and Kashmir. The number for J&K was derived by interpolation for the population of religious communities in the state. Census was not conducted in Assam in the previous census in 1981 due to separatist movements that time. The census data for Assam was done based on interpolation. See also Demographics of India Census town References External links Census Of India, 1991 Category:Censuses in India India Category:Political history of India |
Pyriproxyfen is a pesticide which is found to be effective against a variety of insects. It was introduced to the US in 1996, to protect cotton crops against whitefly. It has also been found useful for protecting other crops. It is also used as a prevention for flea control on household pets, for killing indoor and outdoor ants and roaches. Methods of application include aerosols, bait, carpet powders, foggers, shampoos and pet collars. Pyriproxyfen is a juvenile hormone analog and an insect growth regulator. It prevents larvae from developing into adulthood and thus rendering them unable to reproduce. In the US, pyriproxyfen is often marketed under the trade name Nylar. |
In Europe, pyriproxyfen is known under the brand names Cyclio (Virbac) and Exil Flea Free TwinSpot (Emax). Toxicity in mammals Pyriproxyfen has low acute toxicity. According to WHO and FAO, at elevated doses exceeding 5000 mg/kg of body weight, pyriproxyfen affects the liver in mice, rats and dogs. It also changes cholesterol levels, and may cause modest anemia at high doses. Rumor of link to microcephaly outbreak in Brazil Starting in 2014, pyriproxifen was put into Brazilian water supplies to fight the proliferation of mosquito larvae. This is in line with the World Health Organization (WHO)'s Pesticide Evaluation Scheme (WHOPES) for larvicides. |
In January 2016, the Brazilian Association for Collective Health (Abrasco; ) criticized the introduction of pyriproxyfen in Brazil. Abrasco demanded the "immediate suspension of [use of] pyriproxyfen and all growth inhibitors ... in drinking water." The organization is opposed to the use of growth inhibitors in the context of an ongoing outbreak of fetal malformation. On February 3, the rumor that pyriproxyfen, not the Zika virus, is the cause of the 2015-2016 microcephaly outbreak in Brazil was raised in a report of the Argentinean organization Physicians in the Crop-Sprayed Villages (PCST). It attracted wide media coverage. The statement from Abrasco was cited in the PCST report; subsequently, Abrasco clarified that position as an misinterpretation of their statement, saying "at no time did we state that pesticides, insecticides, or other chemicals are responsible for the increasing number of microcephaly cases in Brazil". |
They also condemned the behavior of the websites that spread the misinformation, adding that such "untruths...violates the anguish and suffering of the people in vulnerable positions". In addition, the coordinator for the PCST statement, Medardo Ávila Vazquez, acknowledged in an interview that "the group hasn’t done any lab studies or epidemiological research to support its assertions, but it argues that using larvicides may cause human deformities." On February 13, the Brazilian state of Rio Grande do Sul suspended pyriproxyfen's use, citing both Abrasco and PCST positions. The Health Minister of Brazil, Marcelo Castro, criticized this step, noting that the claim is "a rumor lacking logic and sense. |
It has no basis." They also noted that the insecticide is approved by the National Sanitary Monitoring Agency and "all regulatory agencies in the whole world". The manufacturer of the insecticide, Sumitomo Chemical, stated "there is no scientific basis for such a claim" and also referred to the approval of pyriproxyfen by the World Health Organization since 2004 and the United States Environmental Protection Agency since 2001. George Dimech, the director of Disease Control and Diseases of the Health Department of Pernambuco in Brazil, gave an interview to the BBC where he pointed out that the city of Recife has the current highest reported number of cases of microcephaly, yet pyriproxyfen is not used in the region, but another insecticide altogether. |
He added that "this lack of spatial correlation weakens the idea that the larvicide is the cause of the problem." In addition, the BBC interviewed researchers in Pernambuco, where no evidence has been found of the cases being linked to any environmental cause like an insecticide. Neurologist Vanessa van der Linden stated in an interview, "Clinically, the changes we see in the scans of babies suggest that the injuries were caused by congenital infection and not by larvicide, drug or vaccine." Noted skeptic David Gorski called the claim a conspiracy theory and pointed out that antivaccine proponents had also claimed that the Tdap vaccine was the cause of the microcephaly outbreak, due to its introduction in 2014, along with adding, "One can’t help but wonder what else the Brazilian Ministry of Health did in 2014 that cranks can blame microcephaly on." |
Gorski also pointed out the extensive physiochemical understanding of pyriproxyfen coded in the WHO Guidelines for Drinking-water Quality, which concluded in a past evaluation that the insecticide is not genotoxic, and that the doctor organization making the claim has been advocating against all pesticides since 2010, complicating their reliability. A professor from the University of Adelaide in Australia, stated that "The effect of pyriproxyfen on reproduction and fetal abnormalities is well studied in animals. In a variety of animal species even enormous quantities of pyriproxyfen do not cause the defects seen during the recent Zika outbreak." A colleague also from the University of Adelaide stated that "While the evidence that Zika virus is responsible for the rise in microcephaly in Brazil is not conclusive, the role of pyriproxyfen is simply not plausible." |
Another professor in Australia concluded that "insect development is quite different to human development and involves different hormones, developmental pathways and sets of genes, so it cannot be assumed that chemicals affecting insect development also influence mammalian development." See also Methoprene References External links Category:Insecticides Category:Pyridines Category:Phenol ethers |
Albumin transport function analysis by EPR spectroscopy (Albumin Transport Analysis test, ATA-test;) is an in vitro blood test that detects changes to the transport and molecular conformation of serum albumin using the method of EPR spectroscopy. The test is used for diagnosis of cancer, sepsis and toxemia. Principles The test is based on the interaction of spin-labeled fatty acids with serum albumin by means of EPR spectroscopy. A sample of blood serum is subjected to a spin probe 16-doxyl stearate. Spin probe molecules bind specifically to albumin molecules where they occupy two main positions: primary binding sites located in albumin domains, where their mobility is restricted the relatively spacious hydrophobic area between the protein domains in the interior of the albumin globule. |
The spin probe molecules bound on albumin have restricted mobility that changes the EPR spectrum, which reflects characteristics of the protein site where the spin probe is located and allows estimating the conformation of the albumin globule. Some part of the spin probe remains in the serum in the unbound state. The ratio of the fractions of bound and unbound spin probes allows estimating the functional activity of albumin molecules. Analysis of the EPR spectrum allows assessment of the conformation and functional activity of albumin molecules. The test material is 100 µl serum or plasma. The procedure includes mixing a serum sample with a spin probe reagent, incubating the mixture, measuring the EPR spectrum of a serum with a spin probe, and analyzing the EPR spectrum by calculating the conformation and functional indicators of albumin molecules. |
Applications Cancer diagnosis A specific change to the conformation of albumin molecules that is associated with the growth of a malignant tumor is caused by (or associated with) changes in the composition of metabolites carried by serum albumin during the growth of a malignant tumor (proliferating cancer cells uptake and release metabolites in abnormal quantities). Clinical studies of the EPR test of serum albumin showed diagnostic sensitivity and specificity of 90%. Clinical applications: as a screening test to detect cancer-specific metabolic alterations in patients; to determine whether the cancer growth has stopped or the disease is progressing; to determine when cancer treatment is effective or needs to be changed. |
Sepsis and toxemia Reduced functional activity of serum albumin (reduced binding efficacy) is associated with toxemia (an increase in the concentration of toxic molecules in the blood) and is manifested before other clinical symptoms. Clinical applications: prognosis and early diagnosis of sepsis (1 to 2 hours after surgery); diagnosis of severe preeclampsia (gestosis) in women in the 2nd and 3rd trimesters of pregnancy; diagnostics of the functional status of a kidney transplant early diagnosis of congenital pneumonia in newborns. References Category:Medical diagnosis Category:Cancer research |
Tempered or toughened glass is a type of safety glass processed by controlled thermal or chemical treatments to increase its strength compared with normal glass. Tempering puts the outer surfaces into compression and the interior into tension. Such stresses cause the glass, when broken, to crumble into small granular chunks instead of splintering into jagged shards as plate glass (a.k.a. annealed glass) does. The granular chunks are less likely to cause injury. As a result of its safety and strength, tempered glass is used in a variety of demanding applications, including passenger vehicle windows, shower doors, architectural glass doors and tables, refrigerator trays, mobile phone screen protectors, as a component of bulletproof glass, for diving masks, and various types of plates and cookware. |
Properties Tempered glass is physically and thermally stronger than normal glass. The greater contraction of the inner layer during manufacturing induces compressive stresses in the surface of the glass balanced by tensile stresses in the body of the glass. For glass to be considered tempered, this compressive stress on the surface of the glass should be a minimum of . For it to be considered safety glass, the surface compressive stress should exceed . As a result of the increased surface stress, if the glass is ever broken it only breaks into small circular pieces as opposed to sharp jagged shards. |
This characteristic makes tempered glass safe for high-pressure and explosion proof applications. It is this compressive stress that gives the tempered glass increased strength. This is because annealed glass, which has almost no internal stress, usually forms microscopic surface cracks, and in the absence of surface compression, any applied tension to the glass causes tension at the surface, which can drive crack propagation. Once a crack starts propagating, tension is further concentrated at the tip of the crack, causing it to propagate at the speed of sound in the material. Consequently, annealed glass is fragile and breaks into irregular and sharp pieces. |
On the other hand, the compressive stresses on a tempered glass contain the flaw and prevent its propagation or expansion. Any cutting or grinding must be done prior to tempering. Cutting, grinding, and sharp impacts after tempering will cause the glass to fracture. The strain pattern resulting from tempering can be observed by viewing through an optical polarizer, such as a pair of polarizing sunglasses. Uses Tempered glass is used when strength, thermal resistance, and safety are important considerations. Passenger vehicles, for example, have all three requirements. Since they are stored outdoors, they are subject to constant heating and cooling as well as dramatic temperature changes throughout the year. |
Moreover, they must withstand small impacts from road debris such as stones as well as automobile accidents. Because large, sharp glass shards would present additional and unacceptable danger to passengers, tempered glass is used so that if broken, the pieces are blunt and mostly harmless. The windscreen or windshield is instead made of laminated glass, which will not shatter into pieces when broken while side windows and the rear windshield are typically tempered glass. Other typical applications of tempered glass include: Balcony doors Athletic facilities Swimming pools Facades Shower doors and bathroom areas Exhibition areas and displays Computer towers or cases Buildings and structures Tempered glass is also used in buildings for unframed assemblies (such as frameless glass doors), structurally loaded applications, and any other application that would become dangerous in the event of human impact. |
Tempered and heat strengthened glass can be three to seven times stronger than annealed glass. Building codes in the United States require tempered or laminated glass in several situations including some skylights, near doorways and stairways, large windows, windows which extend close to floor level, sliding doors, elevators, fire department access panels, and near swimming pools. Household uses Tempered glass is also used in the home. Some common household furniture and appliances that use tempered glass are frameless shower doors, glass table tops, replacement glass, glass shelves, cabinet glass and glass for fireplaces. Food service "Rim-tempered" indicates that a limited area, such as the rim of the glass or plate, is tempered and is popular in food service. |
However, there are also specialist manufacturers that offer a fully tempered/toughened drinkware solution that can bring increased benefits in the form of strength and thermal shock resistance. In some countries these products are specified in venues that require increased performance levels or have a requirement for a safer glass due to intense usage. Tempered glass has also seen increased usage in bars and pubs, particularly in the United Kingdom and Australia, to prevent broken glass being used as a weapon. Tempered glass products can be found in hotels, bars, and restaurants to reduce breakages and increase safety standards. Cooking and baking Some forms of tempered glass are used for cooking and baking. |
Manufacturers and brands include Glasslock, Pyrex, Corelle, and Arc International. This is also the type of glass used for oven doors. Mobile devices Most touchscreen mobile devices use some form of toughened glass (such as Corning's Gorilla Glass), as do some aftermarket screen protectors for these devices. Manufacturing Tempered glass can be made from annealed glass via a thermal tempering process. The glass is placed onto a roller table, taking it through a furnace that heats it well above its transition temperature of to around . The glass is then rapidly cooled with forced air drafts while the inner portion remains free to flow for a short time. |
An alternative chemical toughening process involves forcing a surface layer of glass at least 0.1 mm thick into compression by ion exchange of the sodium ions in the glass surface with potassium ions (which are 30% larger), by immersion of the glass into a bath of molten potassium nitrate. Chemical toughening results in increased toughness compared with thermal tempering and can be applied to glass objects of complex shapes. Disadvantages Tempered glass must be cut to size or pressed to shape before tempering, and cannot be re-worked once tempered. Polishing the edges or drilling holes in the glass is carried out before the tempering process starts. |
Because of the balanced stresses in the glass, damage to any portion will eventually result in the glass shattering into thumbnail-sized pieces. The glass is most susceptible to breakage due to damage to the edge of the glass, where the tensile stress is the greatest, but shattering can also occur in the event of a hard impact in the middle of the glass pane or if the impact is concentrated (for example, striking the glass with a hardened point). Using tempered glass can pose a security risk in some situations because of the tendency of the glass to shatter completely upon hard impact rather than leaving shards in the window frame. |
The surface of tempered glass does exhibit surface waves caused by contact with flattening rollers, if it has been formed using this process. This waviness is a significant problem in manufacturing of thin film solar cells. The float glass process can be used to provide low-distortion sheets with very flat and parallel surfaces as an alternative for different glazing applications. Nickel sulfide defects can cause spontaneous breakage of tempered glass years after its manufacturing. History Francois Barthelemy Alfred Royer de la Bastie (1830–1901) of Paris, France is credited with first developing a method of tempering glass by quenching almost molten glass in a heated bath of oil or grease in 1874, the method patented in England on August 12, 1874, patent number 2783. |
Tempered glass is sometimes known as Bastie glass after de la Bastie. In 1877 the German Friedrich Siemens developed a different process, sometimes called compressed glass or Siemens glass, producing a tempered glass stronger than the Bastie process by pressing the glass in cool molds. The first patent on a whole process to make tempered glass was held by chemist Rudolph A. Seiden who was born in 1900 in Austria and emigrated to the United States in 1935. Though the underlying mechanism was not known at the time, the effects of "tempering" glass have been known for centuries. In about 1660, Prince Rupert of the Rhine brought the discovery of what are now known as "Prince Rupert's Drops" to the attention of King Charles II. |
These are teardrop-shaped bits of glass which are produced by allowing a molten drop of glass to fall into a bucket of water, thereby rapidly cooling it. They can withstand a blow from a hammer on the bulbous end without breaking, but the drops will disintegrate explosively into powder if the tail end is even slightly damaged. See also Gorilla glass Thermal stress Safety glass Borosilicate glass Laminated glass Fire glass Superglass Low-iron glass Stained glass Lead glass References Category:Glass engineering and science Category:Glass types Category:Glass physics pl:Hartowanie#Hartowanie szkła |
The Colorado Springs, CO Metropolitan Statistical Area is a United States Office of Management and Budget defined Metropolitan Statistical Area (MSA) located in the Colorado Springs region of the State of Colorado. The Census Bureau estimates that the population was 668,353 in 2012, a 3.52% increase since the 2010 United States Census. The Colorado Springs MSA is the 79th most populous MSA in the United States. The Colorado Springs MSA encompasses El Paso County and Teller County, Colorado. Approximately 88.40% percent of the MSA's population live in cities or CDPs. The Colorado Springs Metropolitan Statistical Area is the second most populous component of the Front Range Urban Corridor. |
Metropolitan Area Cities and Towns Unincorporated communities Altman Cascade Crystola Falcon Rush Truckton Yoder See also El Paso County, Colorado Teller County, Colorado Colorado census statistical areas Colorado metropolitan areas Combined Statistical Area Core Based Statistical Area Micropolitan Statistical Area Table of United States Combined Statistical Areas Table of United States Metropolitan Statistical Areas Table of United States Micropolitan Statistical Areas Table of United States primary census statistical areas Larger urban regions that contain the Colorado Springs Metropolitan Statistical Area: Front Range Urban Corridor South Central Colorado Urban Area Census statistical areas adjacent to Colorado Springs Metropolitan Statistical Area: Cañon City Micropolitan Statistical Area Denver-Aurora Metropolitan Statistical Area North Central Colorado Urban Area Pueblo Metropolitan Statistical Area References Category:Metropolitan areas of Colorado |
The Riley RM Series is an executive car which was produced by Riley from 1945 to 1955. It was the last model developed independently by Riley prior to the 1952 merger of Riley's still new owner Nuffield, with Austin to form BMC. The RM series was originally produced in Coventry, but in 1949 production moved to the MG works at Abingdon. The RM models were marketed as the Riley 1½ Litre and the Riley 2½ Litre. There were three types of RM vehicles produced. All used Riley engines with four cylinders in-line, hemispherical combustion chambers and twin camshafts mounted high at the sides of the cylinder block. |
The RMA was a large saloon, and was replaced by the RME. Both used a 1.5 L (1496 cc) 12 hp (RAC Rating), developed before WWII. The RMB was a longer car: it was replaced by the RMF. Both cars used a larger engine, new in 1937, a 2.5 L 16 hp (RAC Rating) "Big Four". The RMC and RMD were limited-production cars, an open 2 or 3-seater Roadster and a 4-seater Drophead. __TOC__ Kestrel The RM was inspired by Riley Motors' successful and stylish pre-war 1½ and 2½ Litre Kestrel Saloons but the new cars featured a new chassis. |
The new chassis with its Riley "torsionic" independent front-wheel suspension incorporated the experience of the wartime years. The RM series was new because the patterns of dies for the old models were destroyed in the air raids on Coventry. Riley RMA The RMA was the first post-war Riley. It was announced in August 1945 with the news it would become available in the autumn. It used the 1.5 L engine and was equipped with hydro-mechanical brakes and an independent suspension using torsion bars in front. The body frame (not to be confused with the chassis) was made of wood in the English tradition, and the car featured traditional styling. |
The car was capable of reaching . The RMA was produced from 1945 until 1952 when it was replaced by the RME. Riley RMB The 2.5 L (2443 cc) RMB was a lengthened RMA launched a year later in 1946. It used the 2.5 L (2443 cc) "Big Four" engine with twin SU carburettors, starting with 90 hp (67 kW) but increasing to 100 hp (75 kW) for 1948 with a top speed. The wheelbase was longer and the overall length was a full longer. The RMB was replaced by the RMF for 1952. A car tested by The Motor magazine in 1949 had a top speed of and could accelerate from 0– in 16.8 seconds. |
A fuel consumption of was recorded. The test car cost £1224 including taxes. Riley RMC The RMC (Roadster) was an open 2-door, single bench seat, 2/3-seater version of the RMB, with a large rear deck area and fold-flat windscreen. Announced in March 1948 it was delivered to Geneva just too late to be exhibited at the Geneva Motor Show. Primarily designed for the North American export market it was normally fitted with left-hand drive. The gear change lever was on the steering column. The bonnet and radiator were lowered and the bonnet catches were arranged to be operated internally. Extra over-riders were fitted to the bumpers and the fuel tank was enlarged to 20-gallons. |
Eighteen months later in September 1949 Riley announced future production would include a small quota of cars with right-hand drive. Riley attributed this to a slight increase in the supply of steel. Instead of side windows it was supplied with flexible celluloid-glazed side curtains with a hole for hand signals and, when deployed, flimsy synthetic roofing over a light metal frame. It shared that car's 2.5 L engine, and could reach . Just over 500 were built from 1948 until 1951. Both the back and front of the car bore a remarkable likeness to a 1934 Ford V8. Riley RMD The RMD (drophead) was a traditional 2-door cabriolet, the last cabriolet to wear the Riley name. |
It used the same 2.5 L 100 hp (75 kW) engine as the RMB, on which it was based. Just over 500 were produced between 1949 and 1951. This new body was first displayed in October 1948 at London's Earls Court Motor Show. Riley RME Released in 1952, the RME was an improved RMA. It still used the 1.5 L four and featured a fully hydraulic braking system. The body had an enlarged rear window with curved glass. To improve acceleration the rear axle ratio was changed from 4.89:1 to 5.125:1. When the 2.5 L (2443 cc) car ended production in October 1953 a switch to no running boards was amongst many updates to the RME including wholly new shaped front mudguards. |
Produced from 1952, it was discontinued in 1955 and ultimately its place in the range went in 1957 to the much shorter and unrelated, intended but unused, replacement for the Morris Minor — Riley One-Point-Five also sold as Wolseley 1500 and Morris Major. An RME tested by The Motor magazine in 1952 had a top speed of and could accelerate from 0– in 29.5 seconds. A fuel consumption of was recorded. The test car cost £1,339 including taxes. Riley RMF The RMF replaced the RMB in 1952. It shared that car's 2.5 L "Big Four" engine as well as the mechanical updates from the RME. |
The RMH Riley Pathfinder, the last automobile to use the Riley "Big Four" engine, and thus considered to be the last "real" Riley by purists, took its place after 1953 and continued in production until 1957. Riley 2½-litre Big Four Bibliography A-Z of Cars 1945–1970. Michael Sedgwick and Mark Gillies. Bayview Books. 1989. Book by James Taylor - RILEY RM-SERIES - Book by John Price Williams - The Legendary RMs - Ramsey, John. The Swapmeet and Toyfair Catalogue of British Diecast Model Toys. Swapmeet Toys and Models Ltd. p. 29. References RM Category:1950s cars Category:Rear-wheel-drive vehicles Category:Luxury vehicles Category:Executive cars Category:Sedans Category:Convertibles Category:Cars introduced in 1945 |
Carrier-sense multiple access with collision detection (CSMA/CD) is a media access control (MAC) method used most notably in early Ethernet technology for local area networking. It uses carrier-sensing to defer transmissions until no other stations are transmitting. This is used in combination with collision detection in which a transmitting station detects collisions by sensing transmissions from other stations while it is transmitting a frame. When this collision condition is detected, the station stops transmitting that frame, transmits a jam signal, and then waits for a random time interval before trying to resend the frame. CSMA/CD is a modification of pure carrier-sense multiple access (CSMA). |
CSMA/CD is used to improve CSMA performance by terminating transmission as soon as a collision is detected, thus shortening the time required before a retry can be attempted. With the growing popularity of Ethernet switches in the 1990s, IEEE 802.3 deprecated Ethernet repeaters in 2011, making CSMA/CD and half-duplex operation less common and less important. Procedure The following procedure is used to initiate a transmission. The procedure is complete when the frame is transmitted successfully or a collision is detected during transmission. Is a frame ready for transmission? If not, wait for a frame. Is medium idle? If not, wait until it becomes ready. |
Start transmitting and monitor for collision during transmission. Did a collision occur? If so, go to collision detected procedure. Reset retransmission counters and complete frame transmission. The following procedure is used to resolve a detected collision. The procedure is complete when retransmission is initiated or the retransmission is aborted due to numerous collisions. Continue transmission (with a jam signal instead of frame header/data/CRC) until minimum packet time is reached to ensure that all receivers detect the collision. Increment retransmission counter. Was the maximum number of transmission attempts reached? If so, abort transmission. Calculate and wait the random backoff period based on number of collisions. |
Re-enter main procedure at stage 1. Methods for collision detection are media dependent. On a shared, electrical bus such as 10BASE5 or 10BASE2, collisions can be detected by comparing transmitted data with received data or by recognizing a higher than normal signal amplitude on the bus. On all other media, a carrier sensed on the receive channel while transmitting triggers a collision event. Repeaters or hubs detect collisions on their own and propagate jam signals. The collision recovery procedure can be likened to what happens at a dinner party, where all the guests talk to each other through a common medium (the air). |
Before speaking, each guest politely waits for the current speaker to finish. If two guests start speaking at the same time, both stop and wait for short, random periods of time (in Ethernet, this time is measured in microseconds). The hope is that by each choosing a random period of time, both guests will not choose the same time to try to speak again, thus avoiding another collision. Jam signal The jam signal or jamming signal is a signal that carries a 32-bit binary pattern sent by a data station to inform the other stations of the collision and that they must not transmit. |
The maximum jam-time is calculated as follows: The maximum allowed diameter of an Ethernet installation is limited to 232 bits. This makes a round-trip-time of 464 bits. As the slot time in Ethernet is 512 bits, the difference between slot time and round-trip-time is 48 bits (6 bytes), which is the maximum "jam-time". This in turn means: A station noting a collision has occurred is sending a 4 to 6 byte long pattern composed of 16 1-0 bit combinations. Note: The size of this jam signal is clearly above the minimum allowed frame-size of 64 bytes. The purpose of this is to ensure that any other node which may currently be receiving a frame will receive the jam signal in place of the correct 32-bit MAC CRC, this causes the other receivers to discard the frame due to a CRC error. |
Late collision A late collision is a type of collision that happens further into the packet than is allowed for by the protocol standard in question. In 10 megabit shared medium Ethernet, if a collision error occurs after the first 512 bits of data are transmitted by the transmitting station, a late collision is said to have occurred. Importantly, late collisions are not re-sent by the NIC unlike collisions occurring before the first 64 octets; it is left for the upper layers of the protocol stack to determine that there was loss of data. As a correctly set up CSMA/CD network link should not have late collisions, the usual possible causes are full-duplex/half-duplex mismatch, exceeded Ethernet cable length limits, or defective hardware such as incorrect cabling, non-compliant number of hubs in the network, or a bad NIC. |
Local collision A local collision is a collision that occurs at the NIC as opposed to on the wire. A NIC cannot detect a local collisions without attempting to send information. On UTP cable, a local collision is detected on the local segment only when a station detects a signal on the RX pair at the same time it is sending on the TX pair. Since the two signals are on different pairs there is no characteristic change in the signal. Collisions are only recognized on UTP when the station is operating in half-duplex. The only functional difference between half and full-duplex operation in this regard is whether or not the transmit and receive pairs are permitted to be used simultaneously. |
Channel capture effect The channel capture effect is a phenomenon where one user of a shared medium "captures" the medium for a significant time. During this period (usually 16 frames), other users are denied use of the medium. This effect was first seen in networks using CSMA/CD on Ethernet. Because of this effect, the most data-intense connection dominates the multiple-access wireless channel. This happens in Ethernet links because of the way nodes "back off" from the link and attempt to re-access it. In the Ethernet protocol, when a communication collision happens (when two users of the medium try to send at the same time), each user waits for a random period of time before re-accessing the link. |
However, a user will wait ("back off") for a random amount of time proportional to the number of times it has successively tried to access the link. The channel capture effect happens when one user continues to "win" the link. For example, user A and user B both try to access a quiet link at the same time. Since they detect a collision, user A waits for a random time between 0 and 1 time units and so does user B. Let's say user A chooses a lower back-off time. User A then begins to use the link and B allows it to finish sending its frame. |
If user A still has more to send, then user A and user B will cause another data collision. A will once again choose a random back-off time between 0 and 1, but user B will choose a back-off time between 0 and 3 – because this is B's second time colliding in a row. Chances are A will "win" this one again. If this continues, A will most likely win all the collision battles, and after 16 collisions (the number of tries before a user backs down for an extended period of time), user A will have "captured" the channel. |
The ability of one node to capture the entire medium is decreased as the number of nodes increases. This is because as the number of nodes increases, there is a higher probability that one of the "other" nodes will have a lower back-off time than the capturing node. The channel capture effect creates a situation where one station is able to transmit while others are continually backing off, thus leading to a situation of short-term unfairness. Yet, the situation is long-term fair because every station has the opportunity to "capture" the medium once one station is done transmitting. The efficiency of the channel is increased when one node has captured the channel. |
A negative side effect of the capture effect would be the idle time created due to stations backing off. Once one station is finished transmitting on the medium, large idle times are present because all other stations were continually backing off. In some instances, back-off can occur for so long that some stations actually discard packets because maximum attempt limits have been reached. Applications CSMA/CD was used in now-obsolete shared media Ethernet variants (10BASE5, 10BASE2) and in the early versions of twisted-pair Ethernet which used repeater hubs. Modern Ethernet networks, built with switches and full-duplex connections, no longer need to use CSMA/CD because each Ethernet segment, or collision domain, is now isolated. |
CSMA/CD is still supported for backwards compatibility and for half-duplex connections. The IEEE 802.3 standard, which defines all Ethernet variants, for historical reasons still bore the title "Carrier sense multiple access with collision detection (CSMA/CD) access method and physical layer specifications" until 802.3-2008, which uses new name "IEEE Standard for Ethernet". See also Carrier-sense multiple access with collision avoidance (CSMA/CA) Notes References IEEE 802.3 Category:Media access control Category:Ethernet zh:载波侦听多路访问#CSMA/CD |
Zero Order Phase is the debut solo album by former Nevermore guitarist Jeff Loomis. It was released on September 30, 2008 through Century Media Records. The album was produced by Neil Kernon and features guest appearances by guitarists Ron Jarzombek, Pat O'Brien, and the jazz bassist Michael Manring. An instrumental album, Zero Order Phase was recorded in March 2008 at Robert Lang Studios in Seattle, Washington. In addition to Loomis on guitar, keyboards and bass, the album features ex-Nevermore member Mark Arrington on drums. History Jeff Loomis explained in an interview that the album had been written after the end of This Godless Endeavor tour. |
Loomis wrote two months before starting production. Zero Order Phase was recorded during a month and a half, at the Robert Lang Studios in Richmond Beach, Washington, with producer Neil Kernon and featuring the former Nevermore drummer, Mark Arrington. The choice of Kernon to produce the album had been made several years before while both he and Loomis were working on the third Nevermore album Dreaming Neon Black. Loomis told Kernon that "if I ever did a solo project he would produce it." During the recordings Loomis commented about the album's production, saying: "Being able to do this entire recording with Neil [Kernon] is really amazing as well. |
We've done some great work in the past, but being able to focus on an entire instrumental record is going to be great". The album also features several guest appearances. Ron Jarzombek splits solos with Loomis on "Jato Unit", former Nevermore bandmate Pat O'Brien-who joined Cannibal Corpse after recording The Politics of Ecstasy-on "Race Against Disaster", jazz musician Michael Manring on "Cashmere Shiv" and producer Kernon playing a fretless guitar solo on the same track. As Loomis explained in an interview with Komodo Rock, because the guest musicians lived in different parts of the United States, he e-mailed recordings of the rhythm guitar and drums. |
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