title: Indie pop

text: Despite their relatively minor commercial success (their third album was sardonically titled "They Could Have Been Bigger than the Beatles"), the Television Personalities are highly regarded by critics and have been widely influential, especially on the C86 generation. Simon Reynolds has said that "what we now know as indie music was invented in Scotland," with reference to the emergence of Postcard Records in 1979. However, some have posited that concept of indie music did not crystallise until the late 1980s and early 1990s. Brisbane band "the Go-Betweens" were an early influential indie pop band, releasing their first single "Lee Remick" in 1978. American indie pop band Beat Happening's 1985 eponymous debut album was also influential in the development of the indie pop sound, particularly in North America. In the early 1990s, English indie pop influenced and branched off to a variety of styles. The US, which did not have as much of a scene in the 1980s, had many indie pop enthusiasts by the mid 1990s. Most of the modern notion of indie music stems from "NME"s 1986 compilation "C86", which collects many guitar bands who were inspired by the early psychedelic sounds of 1960s garage rock.


title: Indie pop

text: Names that indie pop fans use for themselves are "popkids" and "popgeeks", and for the music they listen to, "p!o!p", "twee", "anorak" and "C86". Abebe says that the Scottish group the Pastels typified the "hip end of 'anorak': Their lazy melodies, lackadaisical strum, and naive attitude transformed the idea of the rock band into something casual, intimate, and free from the pretense of cool".


title: Indie pop

text: Everett True, a writer for "NME" in the 1980s, believes that "C86" was not the main factor behind indie pop, arguing that Sarah Records was more responsible for sticking to a particular sound, and that: "C86 didn't actually exist as a sound, or style. ... I find it weird, bordering on surreal, that people are starting to use it as a description again". Geoff Taylor, a member of the band Age of Chance, added: "We never considered ourselves part of any scene. I’m not sure that the public at large did either, to be honest. We were just an independent band around at that same time as the others."


title: Indie pop

text: Bob Stanley, a "Melody Maker" journalist in the late 1980s and founding member of pop band Saint Etienne, acknowledges that participants at the time reacted against lazy labelling, but insists they shared an approach: "Of course the 'scene', like any scene, barely existed. Like squabbling Marxist factions, groups who had much in common built up petty rivalries. The June Brides and the Jasmine Minks were the biggest names at Alan McGee's Living Room Club and couldn't stand the sight of each other. Only when the Jesus and Mary Chain exploded and stole their two-headed crown did they realise they were basically soulmates. Manic Street Preachers bassist Nicky Wire remembers that it was the bands' very independence that gave the scene coherence: "People were doing everything themselves - making their own records, doing the artwork, gluing the sleeves together, releasing them and sending them out, writing fanzines because the music press lost interest really quickly."


title: Indie pop

text: Many of the actual "C86" bands distanced themselves from the scene cultivated around them by the UK music press - in its time, "C86" became a pejorative term for its associations with so-called "shambling" (a John Peel-coined description celebrating the self-conscious primitive approach of some of the music) and underachievement.


title: Indie pop

text: Twee pop is a subgenre of indie pop that originates from "C86". Characterised by its simplicity and perceived innocence, some of its defining features are boy-girl harmonies, catchy melodies, and lyrics about love. For many years, most bands were distributed by Sarah Records (in the UK) and K Records (in the US).


title: Indie pop

text: Shibuya-kei is a Japanese style from the 1990s that was embraced by indie pop enthusiasts, partly because many of its bands were distributed in the United States through major indie labels like Matador and Grand Royal. Out of all the Japanese groups from the scene, Pizzicato Five was the closest in achieving mainstream success in the US.


title: Indie pop

text: Chamber pop is a subgenre of indie pop that features lush orchestrations. Heavily influenced by Brian Wilson and Burt Bacharach, the majority of Louis Phillipe's productions for él Records embodied the sophisticated use of orchestras and voices that typified the style, whilst the Divine Comedy were the most popular chamber pop act of the Britpop era.


title: V/H/S

text: V/H/S is a 2012 American found footage horror anthology film and the first installment in the "V/H/S" franchise created by Brad Miska and Bloody Disgusting and produced by Miska and Roxanne Benjamin. It features a series of found footage shorts written and directed by Adam Wingard, David Bruckner, Ti West, Glenn McQuaid, Joe Swanberg, and the filmmaking collective Radio Silence.


title: V/H/S

text: The film debuted at the 2012 Sundance Film Festival in January 2012, and was released on demand on August 31, 2012. The film made its limited theatrical premiere in the United States on October 5, 2012, and in the United Kingdom on January 18, 2013.


title: V/H/S

text: The film spawned five sequels, "V/H/S/2", "", "V/H/S/94, V/H/S/99", "V/H/S/85" and two spin-offs, "Siren" and "Kids vs. Aliens", as well as a miniseries "V/H/S: Video Horror Shorts" on Snapchat's Snap Originals platform.


title: V/H/S

text: In an interview with IndieWire, producer Brad Miska revealed the process in which they developed "V/H/S", which included a "trust-fall" style of filmmaking. All of the relationships came through the long history of Bloody Disgusting.


title: V/H/S

text: The film is presented as an anthology of short horror films, built into a frame narrative which acts as its own short horror film. Each short film is linked together with the concept of found footage (each segment is from the VHS tapes found in the room).


title: V/H/S

text: The frame narrative focuses on a criminal gang who film their exploits, which include smashing the walls, windows, and light fixtures of an abandoned house and sexually assaulting a woman in a parking lot. An anonymous source offers them a large sum of money to break into a house and steal a single VHS videotape. The gang accept the task, eager to expand their criminal enterprises.


title: V/H/S

text: Shane, Patrick, and Clint are three friends who have rented a motel room to fulfill Shane's intent of bringing women back for sex. Clint is wearing glasses that have been outfitted with a hidden camera and microphone that will allow them to turn their planned encounter into an amateur porn video. While the three men are bar-hopping, Clint encounters Lily, a mysterious young woman who appears unusually shy and says little other than "I like you."


title: V/H/S

text: In addition to picking up Lily, the men also succeed in convincing another young woman, Lisa, to return to their motel room. Lisa passes out as Shane attempts to initiate sex while Patrick discourages him from continuing. Lily continues awkwardly coming on to Clint, but it is Shane who comes on to her instead. Clint notices that Lily's feet are clawed and have scales as he undresses her, but Shane and Patrick are oblivious. Lily appears responsive, pushing Shane onto his back and then beginning to undress Clint, seemingly beginning a threesome. Overwhelmed, Clint goes to the bathroom. Patrick disrobes and attempts to take Clint's place, but Lily has made it clear that she dislikes Patrick.


title: V/H/S

text: Moments later, Patrick bursts into the bathroom with a large cut on his hand, claiming that Lily bit him. When they approach Shane, Lily suddenly sprouts fangs, then attacks and kills Shane. Clint and Patrick hide in the bathroom until Patrick, still nude, arms himself with a shower curtain rod and returns to the room. Clint tries to wake Lisa as Patrick attempts to fight Lily, but she subdues and pounces on him, drinking his blood and ripping off his genitals. Clint escapes the room, but ends up falling down a stairwell, breaking his wrist in the process. Lily catches up to Clint, her face hideously contorted, but instead of attacking, she attempts to perform fellatio. As Clint is unresponsive, Lily believes he has rejected her and starts to cry, then growl angrily. Clint flees, begging bystanders for help, but he is suddenly lifted into the sky by Lily, who has transformed into a winged creature, revealing that Lily was actually a succubus on the hunt for a mate. The glasses fall off Clint's face as Lily carries him away, hitting the ground before the footage ends.


title: V/H/S

text: Back in the frame story, one of the criminals discovers that Brad, the person who stayed to watch the tape, is missing. Meanwhile, the other criminals search the basement and discover hundreds of unmarked VHS tapes, and begin collecting them all to ensure they get the right one. One of them manages to catch a glimpse of a strange figure wandering off when they gather the tapes. The criminal still upstairs, Rox, replaces the tape in the VCR with a different one and settles down to watch it.


title: V/H/S

text: Sam and Stephanie are a married couple travelling to Arizona for their honeymoon, with Stephanie recording and documenting everything along the way. That night, they visit a Wild West-themed attraction known as "Wild West Junction", where Stephanie receives a prediction from a mechanical fortune teller dressed as a prospector. The prediction claims that she will soon be happily reunited with a loved one, and that she is also very trusting and is easily taken advantage of. Sometime later, a strange woman comes to Sam and Stephanie's motel room and awkwardly tries to convince Sam (off camera) to give her a ride somewhere the next day.


title: V/H/S

text: A group of 20-somethings, Joey, Spider, and Samantha, accompany their new friend, Wendy, on her annual trip to a lake located in a nearby forest. Joey films the group as Wendy leads them through the woods, occasionally mentioning "accidents" that took the lives of her friends. When the camera scans certain areas, glitched images of mutilated bodies appear in the film. They also discover the mutilated corpse of a pig nearby, shortly before Wendy mentions that everyone is going to die. Relaxing and smoking weed by the lake, Wendy tells the others that the lake is the same place where a murderer killed many people years earlier, but the group laughs it off as a joke.


title: V/H/S

text: Told entirely through a series of computer video chats, Emily tells her boyfriend James, an aspiring doctor, about a strange bump on her arm and how it reminds her of an accident she had when she was younger. After showing James around her apartment, Emily hears noises outside her door. After investigating the room, Emily witnesses a small, ghostly, childlike entity rush into her room and slam the door shut, leading her to believe that her apartment is haunted. Hearing the noises again the next night, Emily attempts to investigate some more, only to discover the entity again when she turns on the light. She questions her landlord about the disturbances, but the landlord claims that no children have ever lived in the apartment complex, nor have any people ever died there, but Emily is unconvinced. During her next video chat with James, Emily nonchalantly digs into the bump on her arm with a scalpel and a meat fork to find out what exactly the bump is, but James urges her to stop before the wound becomes infected, promising to check on it himself when he arrives in a week.


title: V/H/S

text: On Halloween night 1998, Tyler, dressed as a teddy bear implanted with a nanny cam, meets his friends, Chad, Matt, and Paul (dressed as the Unabomber, a pirate, and a Marine, respectively) as they head out to a Halloween party at a friend's house, only to end up at the wrong place. Thinking that they are the first ones to arrive, the quartet sneak inside. They begin to experience paranormal phenomena, but believe that they are at a realistic haunted house attraction and have fun with it.


title: V/H/S

text: A joke ending was shot in one take by Radio Silence, in which the doors are unlocked and the boys get out just before the train smashes into their car. The boys walk away and talk about how much fun they had, and what a crazy night it was. Meanwhile, the train hits the car and it explodes behind them.


title: V/H/S

text: Trevor Groth, a programmer of midnight movies at the Sundance Film Festival, said, "I give this all the credit in the world because conceptually it shouldn't have worked for me. Personally, I'm bored by found-footage horror films, which this is. And omnibus attempts rarely work. But this one does. It's terrifying, and very well executed." Horror-Movies.ca reported that two people fainted during the premiere at Sundance.


title: V/H/S

text: At the 2012 Sundance Film Festival, Magnolia Pictures purchased the North American rights to the film for slightly over $1 million. The first theatrical release began in Russia September 7, 2012. Limited theatrical release began October 5, 2012 in the United States. The film was released onto DVD, Blu-ray, and digital download on December 4, 2012. It was released on the titular format of VHS on February 5, 2013.


title: V/H/S

text: The film holds a 57% approval rating on Rotten Tomatoes, based on 101 reviews with an average rating of 5.62/10. The website's critical consensus reads, "An uneven collection of found-footage horror films, "V/H/S" has some inventive scares but its execution is hit-and-miss." Metacritic, which assigns a weighted mean rating out of 100 to reviews from mainstream critics, the film holds an average score of 55, based on reviews from 21 critics, indicating "mixed or average reviews".


title: V/H/S

text: Most reviewers said that they felt the film was too long. "Variety" noted that "the segments vary in quality and the whole overstays its welcome at nearly two hours. Some trimming (perhaps relegating a weaker episode to a DVD extra) would increase theatrical chances."


title: V/H/S

text: "Empire" gave the film four stars out of five, saying that "the biggest twist is its consistently high quality ... anything goes, and all of it works". "The Hollywood Reporter" gave the film a mildly positive review, stating "Refreshingly, "V/H/S" promises no more than it delivers, always a plus with genre fare." "Fangoria" praised the film while remarking that "the mystery of why/how some of this stuff is even on VHS tapes to begin with" was a bit of a leap.


title: V/H/S

text: Sean O'Connell of "The Washington Post" gave the film a scathing review, saying that although "on paper, it's a clever concept" and "probably sounded great in the pitch meeting", it "loses all luster through some shoddy execution". He went on to criticise the "unwatchable shaky-cam technique" and "rough and amateurish" acting, though he did identify Swanberg's segment as the best. Likewise, Roger Ebert was among the critics who felt the film was overlong, giving the film one star out of four and saying that "None of the segments is particularly compelling. Strung together, it's way too much of a muchness."


title: V/H/S

text: A sequel, titled "V/H/S/2", was debuted at January 19 as part of Sundance 2013. The film was released via VOD on June 6, and theatrically on July 12. A third entry in the series, titled "", was released on Video on Demand on October 23, 2014, and in theatres on November 21 of the same year.


title: V/H/S

text: A spin-off based on the segment "Amateur Night", entitled "Siren" released theatrically on December 2, 2016.


title: V/H/S

text: A 4-episode miniseries "V/H/S: Video Horror Shorts" was released on Snap Originals on October 28, 2018.


title: V/H/S

text: A reboot titled "V/H/S/94" was released exclusively on Shudder on October 6, 2021. The sequel "V/H/S/99" debuted in the Midnight Madness stream at the 2022 Toronto International Film Festival and was released on Shudder October 20, 2022.


title: V/H/S

text: A second spin-off film "Kids vs. Aliens", a feature-length adaptation of "Slumber Party Alien Abduction", from Jason Eisener's segment from "V/H/S/2" premiered at Fantastic Fest in 2022 and is set to be released in 2023 by RLJE Films and Shudder.


title: Arachnid

text: Arachnida () is a class of joint-legged invertebrate animals (arthropods), in the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegaroons.


title: Arachnid

text: Almost all adult arachnids have eight legs, although the front pair of legs in some species has converted to a sensory function, while in other species, different appendages can grow large enough to take on the appearance of extra pairs of legs. The term is derived from the Greek word ("aráchnē", 'spider'), from the myth of the hubristic human weaver Arachne, who was turned into a spider.


title: Arachnid

text: Almost all extant arachnids are terrestrial, living mainly on land. However, some inhabit freshwater environments and, with the exception of the pelagic zone, marine environments as well. They comprise over 100,000 named species, of which 47,000 are species of spiders.


title: Arachnid

text: Almost all adult arachnids have eight legs, unlike adult insects which all have six legs. However, arachnids also have two further pairs of appendages that have become adapted for feeding, defense, and sensory perception. The first pair, the chelicerae, serve in feeding and defense. The next pair of appendages, the pedipalps, have been adapted for feeding, locomotion, and/or reproductive functions. In Solifugae, the palps are quite leg-like, so that these animals appear to have ten legs. The larvae of mites and Ricinulei have only six legs; a fourth pair usually appears when they moult into nymphs. However, mites are variable: as well as eight, there are adult mites with six or, like in Eriophyoidea, even four legs. And while the adult males in some members of Podapolipidae have six legs, the adult females have only a single pair.


title: Arachnid

text: Arachnids are further distinguished from insects by the fact they do not have antennae or wings. Their body is organized into two tagmata, called the prosoma, or cephalothorax, and the opisthosoma, or abdomen. (However, there is currently neither fossil nor embryological evidence that arachnids ever had a separate thorax-like division, so the validity of the term cephalothorax, which means a fused cephalon, or head, and thorax, has been questioned. There are also arguments against use of 'abdomen', as the opisthosoma of many arachnids contains organs atypical of an abdomen, such as a heart and respiratory organs.) The prosoma, or cephalothorax, is usually covered by a single, unsegmented carapace. The abdomen is segmented in the more primitive forms, but varying degrees of fusion between the segments occur in many groups. It is typically divided into a preabdomen and postabdomen, although this is only clearly visible in scorpions, and in some orders, such as the Acari, the abdominal sections are completely fused. A telson is present in scorpions, where it has been modified to a stinger, and into a flagellum in the Palpigradi, Schizomida (very short) and whip scorpions. At the base of the flagellum in the two latter groups there are gland who produce acetic acid as a chemical defense. Except for a pair of pectines in scorpions, and the spinnerets in spiders, the abdomen has no appendages.


title: Arachnid

text: Like all arthropods, arachnids have an exoskeleton, and they also have an internal structure of cartilage-like tissue, called the endosternite, to which certain muscle groups are attached. The endosternite is even calcified in some Opiliones.


title: Arachnid

text: Most arachnids lack extensor muscles in the distal joints of their appendages. Spiders and whipscorpions extend their limbs hydraulically using the pressure of their hemolymph. Solifuges and some harvestmen extend their knees by the use of highly elastic thickenings in the joint cuticle. Scorpions, pseudoscorpions and some harvestmen have evolved muscles that extend two leg joints (the femur-patella and patella-tibia joints) at once. The equivalent joints of the pedipalps of scorpions though, are extended by elastic recoil.


title: Arachnid

text: There are characteristics that are particularly important for the terrestrial lifestyle of arachnids, such as internal respiratory surfaces in the form of tracheae, or modification of the book gill into a book lung, an internal series of vascular lamellae used for gas exchange with the air. While the tracheae are often individual systems of tubes, similar to those in insects, ricinuleids, pseudoscorpions, and some spiders possess sieve tracheae, in which several tubes arise in a bundle from a small chamber connected to the spiracle. This type of tracheal system has almost certainly evolved from the book lungs, and indicates that the tracheae of arachnids are not homologous with those of insects.


title: Arachnid

text: Further adaptations to terrestrial life are appendages modified for more efficient locomotion on land, internal fertilisation, special sensory organs, and water conservation enhanced by efficient excretory structures as well as a waxy layer covering the cuticle.


title: Arachnid

text: The excretory glands of arachnids include up to four pairs of coxal glands along the side of the prosoma, and one or two pairs of Malpighian tubules, emptying into the gut. Many arachnids have only one or the other type of excretory gland, although several do have both. The primary nitrogenous waste product in arachnids is guanine.


title: Arachnid

text: Arachnid blood is variable in composition, depending on the mode of respiration. Arachnids with an efficient tracheal system do not need to transport oxygen in the blood, and may have a reduced circulatory system. In scorpions and some spiders, however, the blood contains haemocyanin, a copper-based pigment with a similar function to haemoglobin in vertebrates. The heart is located in the forward part of the abdomen, and may or may not be segmented. Some mites have no heart at all.


title: Arachnid

text: Arachnids are mostly carnivorous, feeding on the pre-digested bodies of insects and other small animals. But ticks, and many mites, are parasites, some of which are carriers of disease. The diet of mites also include tiny animals, fungi, plant juices and decomposing matter. Almost as varied is the diet of harvestmen, where we will find predators, decomposers and omnivores feeding on decaying plant and animal matter, droppings, animals and mushrooms. The harvestmen and some mites, such as the house dust mite, are also the only arachnids able to ingest solid food, which exposes them to internal parasites, although it is not unusual for spiders to eat their own silk. And one species of spider is mostly herbivorous. Scorpions, spiders and pseudoscorpions secrete venom from specialized glands to kill prey or defend themselves. Their venom also contains pre-digestive enzymes that helps breaking down the prey. The saliva of ticks contains anticoagulants and anticomplements, and several species produce a neurotoxin.


title: Arachnid

text: Arachnids produce digestive enzymes in their stomachs, and use their pedipalps and chelicerae to pour them over their dead prey. The digestive juices rapidly turn the prey into a broth of nutrients, which the arachnid sucks into a pre-buccal cavity located immediately in front of the mouth. Behind the mouth is a muscular, sclerotised pharynx, which acts as a pump, sucking the food through the mouth and on into the oesophagus and stomach. In some arachnids, the oesophagus also acts as an additional pump.


title: Arachnid

text: The stomach is tubular in shape, with multiple diverticula extending throughout the body. The stomach and its diverticula both produce digestive enzymes and absorb nutrients from the food. It extends through most of the body, and connects to a short sclerotised intestine and anus in the hind part of the abdomen.


title: Arachnid

text: Arachnids have two kinds of eyes: the lateral and median ocelli. The lateral ocelli evolved from compound eyes and may have a tapetum, which enhances the ability to collect light. With the exception of scorpions, which can have up to five pairs of lateral ocelli, there are never more than three pairs present. The median ocelli develop from a transverse fold of the ectoderm. The ancestors of modern arachnids probably had both types, but modern ones often lack one type or the other. The cornea of the eye also acts as a lens, and is continuous with the cuticle of the body. Beneath this is a transparent vitreous body, and then the retina and, if present, the tapetum. In most arachnids, the retina probably does not have enough light sensitive cells to allow the eyes to form a proper image.


title: Arachnid

text: In addition to the eyes, almost all arachnids have two other types of sensory organs. The most important to most arachnids are the fine sensory hairs that cover the body and give the animal its sense of touch. These can be relatively simple, but many arachnids also possess more complex structures, called trichobothria.


title: Arachnid

text: Finally, slit sense organs are slit-like pits covered with a thin membrane. Inside the pit, a small hair touches the underside of the membrane, and detects its motion. Slit sense organs are believed to be involved in proprioception, and possibly also hearing.


title: Arachnid

text: Arachnids may have one or two gonads, which are located in the abdomen. The genital opening is usually located on the underside of the second abdominal segment. In most species, the male transfers sperm to the female in a package, or spermatophore. The males in harvestmen and some mites have a penis. Complex courtship rituals have evolved in many arachnids to ensure the safe delivery of the sperm to the female. Members of many orders exhibit sexual dimorphism.


title: Arachnid

text: Arachnids usually lay yolky eggs, which hatch into immatures that resemble adults. Scorpions, however, are either ovoviviparous or viviparous, depending on species, and bear live young. Also some mites are ovoviviparous and viviparous, even if most lay eggs. In most arachnids only the females provide parental care, with harvestmen being one of the few exceptions.


title: Arachnid

text: The phylogenetic relationships among the main subdivisions of arthropods have been the subject of considerable research and dispute for many years. A consensus emerged from about 2010 onwards, based on both morphological and molecular evidence. Extant (living) arthropods are a monophyletic group and are divided into three main clades: chelicerates (including arachnids), pancrustaceans (the paraphyletic crustaceans plus insects and their allies), and myriapods (centipedes, millipedes and allies). The three groups are related as shown in the cladogram below. Including fossil taxa does not fundamentally alter this view, although it introduces some additional basal groups.


title: Arachnid

text: The extant chelicerates comprise two marine groups: sea spiders and horseshoe crabs, and the terrestrial arachnids. These have been thought to be related as shown below. (Pycnogonida (sea spiders) may be excluded from the chelicerates, which are then identified as the group labelled "Euchelicerata".) A 2019 analysis nests Xiphosura deeply within Arachnida.


title: Arachnid

text: Discovering relationships within the arachnids has proven difficult , with successive studies producing different results. A study in 2014, based on the largest set of molecular data to date, concluded that there were systematic conflicts in the phylogenetic information, particularly affecting the orders Acariformes, Parasitiformes and Pseudoscorpiones, which have had much faster evolutionary rates. Analyses of the data using sets of genes with different evolutionary rates produced mutually incompatible phylogenetic trees. The authors favoured relationships shown by more slowly evolving genes, which demonstrated the monophyly of Chelicerata, Euchelicerata and Arachnida, as well as of some clades within the arachnids. The diagram below summarizes their conclusions, based largely on the 200 most slowly evolving genes; dashed lines represent uncertain placements.


title: Arachnid

text: Tetrapulmonata, here consisting of Araneae, Amblypygi and Thelyphonida (Schizomida was not included in the study), received strong support. The addition of Scorpiones to produce a clade called Arachnopulmonata was also well supported. Pseudoscorpiones may also belong here, as all six orders share the same ancient whole genome duplication, and analyses support pseudoscorpions as the sister group of scorpions. Somewhat unexpectedly, there was support for a clade comprising Opiliones, Ricinulei and Solifugae, a combination not found in most other studies.


title: Arachnid

text: In early 2019, a molecular phylogenetic analysis placed the horseshoe crabs, Xiphosura, as the sister group to Ricinulei. It also grouped pseudoscorpions with mites and ticks, which the authors considered may be due to long branch attraction.


title: Arachnid

text: Morphological analyses including fossils tend to recover the Tetrapulmonata, including the extinct group the Haptopoda, but recover other ordinal relationships with low support.


title: Arachnid

text: A fossil arachnid in 100 million year old (mya) amber from Myanmar, "Chimerarachne yingi", has spinnerets (to produce silk); it also has a tail, like the Palaeozoic Uraraneida, some 200 million years after other known fossils with tails. The fossil resembles the most primitive living spiders, the mesotheles.


title: Arachnid

text: The subdivisions of the arachnids are usually treated as orders. Historically, mites and ticks were treated as a single order, Acari. However, molecular phylogenetic studies suggest that the two groups do not form a single clade, with morphological similarities being due to convergence. They are now usually treated as two separate taxa – Acariformes, mites, and Parasitiformes, ticks – which may be ranked as orders or superorders. The arachnid subdivisions are listed below alphabetically; numbers of species are approximate.


title: Arachnid

text: It is estimated that 98,000 arachnid species have been described, and that there may be up to 600,000 in total.


title: North American XB-70 Valkyrie

text: The North American Aviation XB-70 Valkyrie was the prototype version of the planned B-70 nuclear-armed, deep-penetration supersonic strategic bomber for the United States Air Force Strategic Air Command. Designed in the late 1950s by North American Aviation (NAA), the six-engined Valkyrie was capable of cruising for thousands of miles at Mach 3+ while flying at .


title: North American XB-70 Valkyrie

text: At these speeds, it was expected that the B-70 would be practically immune to interceptor aircraft, the only effective weapon against bomber aircraft at the time. The bomber would spend only a brief time over a particular radar station, flying out of its range before the controllers could position their fighters in a suitable location for an interception. Its high speed made the aircraft difficult to see on radar displays and its high-altitude and high-speed capabilities could not be matched by any contemporaneous Soviet interceptor or fighter aircraft.


title: North American XB-70 Valkyrie

text: The introduction of the first Soviet surface-to-air missiles in the late 1950s put the near-invulnerability of the B-70 in doubt. In response, the United States Air Force (USAF) began flying its missions at low level, where the missile radar's line of sight was limited by terrain. In this low-level penetration role, the B-70 offered little additional performance over the B-52 it was meant to replace, while being far more expensive with shorter range. Other alternate missions were proposed, but these were of limited scope. With the advent of intercontinental ballistic missiles (ICBMs) during the late 1950s, manned bombers were increasingly seen as obsolete.


title: North American XB-70 Valkyrie

text: The USAF eventually gave up fighting for its production and the B-70 program was canceled in 1961. Development was then turned over to a research program to study the effects of long-duration high-speed flight. As such, two prototype aircraft, designated "XB-70A", were built; these aircraft were used for supersonic test-flights during 1964–69. In 1966, one prototype crashed after colliding with a smaller aircraft while flying in close formation; the remaining Valkyrie bomber is in the National Museum of the United States Air Force near Dayton, Ohio.


title: North American XB-70 Valkyrie

text: In an offshoot of Boeing's MX-2145 manned boost-glide bomber project, Boeing partnered with RAND Corporation in January 1954 to explore what sort of bomber aircraft would be needed to deliver the various contemporary nuclear weapons under development. At the time, nuclear weapons weighed several tons, and the need to carry enough fuel to fly that payload from the continental United States to the Soviet Union demanded large bombers. They also concluded that after the release of the bombs, the aircraft would need supersonic speed to escape the critical blast-radius.


title: North American XB-70 Valkyrie

text: The aviation industry had been studying this problem for some time. From the mid-1940s, there was interest in using nuclear-powered aircraft in the bomber role. In a conventional jet engine, thrust is provided by heating air using jet fuel and accelerating it out a nozzle. In a nuclear engine, heat is supplied by a reactor, whose consumables last for months instead of hours. Most designs also carried a small amount of jet fuel for use during high-power portions of flight, such as takeoffs and high-speed dashes.


title: North American XB-70 Valkyrie

text: Another possibility being explored at the time was the use of boron-enriched "zip fuels", which improve the energy density of jet fuel by about 40 percent, and could be used in modified versions of existing jet engine designs. Zip fuels appeared to offer sufficient performance improvement to produce a strategic bomber with supersonic speed.


title: North American XB-70 Valkyrie

text: The U.S. Air Force (USAF) followed these developments closely, and in 1955 issued General Operational Requirement No. 38 for a new bomber, combining the payload and intercontinental range of the B-52 with the Mach 2 top speed of the Convair B-58 Hustler. The new bomber was expected to enter service in 1963. Both nuclear and conventional designs were considered. The nuclear-powered bomber was organized as "Weapon System 125A" and pursued simultaneously with the jet-powered version, "Weapon System 110A".


title: North American XB-70 Valkyrie

text: The USAF Air Research and Development Command's (ARDC) requirement for WS-110A asked for a chemical-fuel bomber with Mach 0.9 cruising speed and "maximum possible" speed during a entrance and exit from the target. The requirement also called for a payload and a combat radius of . The Air Force formed similar requirements for a WS-110L intercontinental reconnaissance system in 1955, but this was later canceled in 1958 due to better options. In July 1955, six contractors were selected to bid on WS-110A studies. Boeing and North American Aviation submitted proposals, and on 8 November 1955 were awarded contracts for Phase 1 development.


title: North American XB-70 Valkyrie

text: In mid-1956, initial designs were presented by the two companies. Zip fuel was to be used in the afterburners to improve range by 10 to 15 percent over conventional fuel. Both designs featured huge wing-tip fuel tanks that could be jettisoned when their fuel was depleted before a supersonic dash to the target. The tanks also included the outer portions of the wing, which would also be jettisoned to produce a smaller wing suitable for supersonic speeds. Both became trapezoidal wings after ejection, at that time the highest performance planform known. They also featured flush cockpits to maintain the highest fineness ratio possible in spite of its effects on visibility.


title: North American XB-70 Valkyrie

text: The two designs had takeoff weights of approximately with large fuel loads. The Air Force evaluated the designs, and in September 1956 deemed them too large and complicated for operations. General Curtis LeMay was dismissive, declaiming, "This is not an airplane, it's a three-ship formation." The USAF ended Phase 1 development in October 1956 and instructed the two contractors to continue design studies.


title: North American XB-70 Valkyrie

text: While the original proposals were being studied, advances in supersonic flight were proceeding rapidly. The narrow delta was establishing itself as a preferred planform for supersonic flight, replacing earlier designs like the swept-wing and trapezoidal layouts seen on designs like the Lockheed F-104 Starfighter and the earlier WS-110 concepts. Engines able to cope with higher temperatures were also under development, allowing for sustained supersonic speeds.


title: North American XB-70 Valkyrie

text: This work led to an interesting discovery: when an engine was optimized specifically for high speed, it burned perhaps twice as much fuel at that speed than when it was running at subsonic speeds. However, the aircraft would be flying as much as four times as fast. Thus its most economical cruise speed, in terms of fuel per mile, was its maximum speed. This was entirely unexpected and implied that there was no point in the dash concept; if the aircraft was able to reach Mach 3, it may as well fly its entire mission at that speed. The question remained whether such a concept was technically feasible, but by March 1957, engine development and wind tunnel testing had progressed enough to suggest that it was.


title: North American XB-70 Valkyrie

text: WS-110 was redesigned to fly at Mach 3 for the entire mission. Zip fuel was retained for the engine's afterburner to increase range. Both North American and Boeing returned new designs with very long fuselages and large delta wings. They differed primarily in engine layout; the NAA design arranged its six engines in a semi-circular duct under the rear fuselage, while the Boeing design used separate podded engines located individually on pylons below the wing, like the Hustler.


title: North American XB-70 Valkyrie

text: North American scoured available literature to find any additional advantage. This led them to an obscure report by two NACA wind tunnel experts, who wrote a report in 1956 titled "Aircraft Configurations Developing High Lift-Drag Ratios at High Supersonic Speeds". Known today as compression lift, the idea was to use the shock wave generated off the nose or other sharp points on the aircraft as a source of high-pressure air. By carefully positioning the wing in relation to the shock, the shock's high pressure could be captured on the bottom of the wing and generate additional lift. To take maximum advantage of this effect, they redesigned the underside of the aircraft to feature a large triangular intake area far forward of the engines, better positioning the shock in relation to the wing. The six individually-podded engines were repositioned, three in each of two separate ducts, under the fuselage.


title: North American XB-70 Valkyrie

text: North American improved on the basic concept by adding a set of drooping wing-tip panels that were lowered at high speed. This helped trap the shock wave under the wing between the downturned wing tips. It also added more vertical surface to the aircraft to maintain directional stability at high speeds. NAA's solution had an additional advantage, as it decreased the surface area of the rear of the wing when the panels were moved into their high-speed position. This helped offset the natural rearward shift of the center of pressure, or "average lift point", with increasing speeds. Under normal conditions this caused an increasing nose-down trim, which had to be offset by moving the control surfaces, increasing drag. When the wing tips were drooped, the lifting area of the wings was lessened, moving the lift forward and reducing trim drag.


title: North American XB-70 Valkyrie

text: The buildup of heat due to skin friction during sustained supersonic flight had to be addressed. During a Mach 3 cruise, the aircraft would reach an average of , with leading edges reaching , and up to in engine compartments. NAA proposed building their design out of sandwich panels, with each panel consisting of two thin sheets of stainless steel brazed to opposite faces of a honeycomb-shaped foil core. Expensive titanium would be used only in high-temperature areas like the leading edge of the horizontal stabilizer, and the nose. To cool the interior, the XB-70 pumped fuel en route to the engines through heat exchangers.


title: North American XB-70 Valkyrie

text: On 30 August 1957, the Air Force decided that enough data were available on the NAA and Boeing designs that a competition could begin. On 18 September, the Air Force issued operational requirements that called for a cruising speed of Mach 3.0 to 3.2, an over-target altitude of , a range of up to , and a gross weight not to exceed . The aircraft would have to use the hangars, runways and handling procedures used by the B-52. On 23 December 1957, the North American proposal was declared the winner of the competition, and on 24 January 1958, a contract was issued for Phase 1 development.


title: North American XB-70 Valkyrie

text: In February 1958, the proposed bomber was designated "B-70", with the prototypes receiving the "X" experimental prototype designation. The name "Valkyrie" was the winning submission in early 1958, selected from 20,000 entries in a USAF "Name the B-70" contest. The Air Force approved an 18-month program acceleration in March 1958 that rescheduled the first flight to December 1961. But in late 1958 the service announced that this acceleration would not be possible due to lack of funding. In December 1958, a Phase II contract was issued. The mockup of the B-70 was reviewed by the Air Force in March 1959. Provisions for air-to-surface missiles and external fuel tanks were requested afterward. At the same time, North American was developing the F-108 supersonic interceptor. To reduce program costs, the F-108 would share two of the engines, the escape capsule, and some smaller systems with the B-70. In early 1960, North American and the USAF released the first drawing of the XB-70 to the public.


title: North American XB-70 Valkyrie

text: The B-70 was planned to use a high-speed, high-altitude bombing approach that followed a trend of bombers flying progressively faster and higher since the start of manned bomber use. Through that same period, only two weapons proved effective against bombers: fighter aircraft and anti-aircraft artillery (AAA). Flying higher and faster made it more difficult for both; higher speeds allowed the bomber to fly out of range of the weapons more quickly, while higher altitudes increased the time needed for fighters to climb to the bombers, and greatly increased the size of the AAA weapons needed to reach those altitudes.


title: North American XB-70 Valkyrie

text: As early as 1942, German flak commanders had already concluded that AAA would be essentially useless against jet aircraft, and began development of guided missiles to fill this role. Most forces reached the same conclusion soon after, with both the US and UK starting missile development programs before the war ended. The UK's Green Mace was one of the last attempts to develop a useful high-altitude AAA weapon, but its development ended in 1957.


title: North American XB-70 Valkyrie

text: Interceptor aircraft with ever-improving performance remained the only effective anti-bomber weapons by the early 1950s, and even these were having problems keeping up with the latest designs; Soviet interceptors during the late 1950s could not intercept the high-altitude U-2 reconnaissance aircraft, despite its relatively low speeds. It was later discovered that flying faster also made radar detection much more difficult due to an effect known as the blip-to-scan ratio, and any reduction in tracking efficiency would further interfere with the operation and guidance of fighters.


title: North American XB-70 Valkyrie

text: The introduction of the first effective anti-aircraft missiles by the late 1950s changed this picture dramatically. Missiles could stand ready for immediate launch, eliminating operational delays like the time needed to get the pilot into the cockpit of a fighter. Guidance did not require wide-area tracking or calculation of an intercept course: a simple comparison of the time needed to fly to the altitude of the target returned the required deflection. Missiles also had greater altitude capability than any aircraft and improving this to adapt to new aircraft was a low-cost development path. The US was aware of Soviet work in the field, and had reduced the expected operational lifetime of the U-2, knowing that it would become vulnerable to these missiles as they were improved. In 1960, a U-2 flown by Gary Powers was shot down by one of the earliest Soviet guided air-defence missiles, the S-75 Dvina, known in the west as the SA-2 Guideline.


title: North American XB-70 Valkyrie

text: Faced with this problem, military doctrine had already started shifting away from high-altitude supersonic bombing toward low-altitude "penetration". Radar is line-of-sight, so aircraft could dramatically shorten detection distances by flying close to the Earth and hiding behind terrain. Missile sites spaced to overlap in range when attacking bombers at high altitudes would leave large gaps between their coverage for bombers flying at lower levels. With an appropriate map of the missile sites, the bombers could fly between and around the defenses. Additionally, early missiles generally flew unguided for a period of time before the radar systems were able to track the missile and start sending it guidance signals. With the SA-2 missile, this minimum altitude was roughly .


title: North American XB-70 Valkyrie

text: Flying at low level provided protection against fighters as well. Radars of the era did not have the ability to look down (see look-down/shoot-down); if a higher altitude aircraft's radar was aimed down to detect targets at a lower altitude, the reflection of the ground would overwhelm the signal returned from a target. An interceptor flying at normal altitudes would be effectively blind to bombers far below it. The interceptor could descend to lower altitudes to increase the amount of visible sky, but doing so would limit its radar range in the same way as the missile sites, as well as greatly increasing fuel use and thus reducing mission time. The Soviet Union would not introduce an interceptor with look-down capability until 1972 with the High Lark radar in the MiG-23M, and even this model had very limited capability.


title: North American XB-70 Valkyrie

text: Strategic Air Command found itself in an uncomfortable position; bombers had been tuned for efficiency at high speeds and altitudes, performance that had been purchased at great cost in both engineering and financial terms. Before the B-70 was to replace the B-52 in the long-range role, SAC had introduced the B-58 Hustler to replace the Boeing B-47 Stratojet in the medium-range role. The Hustler was expensive to develop and purchase, and required enormous amounts of fuel and maintenance in comparison to the B-47. It was estimated that it cost three times as much to operate as the much larger and longer-ranged B-52.


title: North American XB-70 Valkyrie

text: The B-70, designed for even higher speeds, altitudes and range than the B-58, suffered even more in relative terms. At high altitudes, the B-70 was as much as four times as fast as the B-52, but at low altitudes it was limited to only Mach 0.95, only modestly faster than the B-52 at the same altitudes. It also had a smaller bombload and shorter range. Its only major advantage would be its ability to use high speed in areas without missile cover, especially on the long journey from the US to USSR. The value was limited; the USAF's doctrine stressed that the primary reason for maintaining the bomber force in an era of ICBMs was that the bombers could remain in the air at long ranges from their bases and were thus immune to sneak attack. In this case, the higher speed would be used for only a short period of time between the staging areas and the Soviet coastline.


title: North American XB-70 Valkyrie

text: Adding to the problems, the zip fuel program was canceled in 1959. After burning, the fuel turned into liquids and solids that increased wear on moving turbine engine components. Although the B-70 was intended to use zip only in the afterburners, and thus avoid this problem, the enormous cost of the zip program for such limited gains led to its cancellation. This by itself was not a fatal problem, however, as newly developed high-energy fuels like JP-6 were available to make up some of the difference. Most of the range lost in the change from zip fuel was restored by filling one of the two bomb bays with a fuel tank. However, another problem arose when the XF-108 program was canceled in September 1959, which ended the shared development that benefited the B-70 program.


title: North American XB-70 Valkyrie

text: At two secret meetings on 16 and 18 November 1959, the Chairman of the Joint Chiefs of Staff, Air Force General Twining, recommended the Air Force's plan for the B-70 to reconnoiter and strike rail-mobile Soviet ICBMs, but the Chief of Staff of the Air Force, General White, admitted the Soviets would "be able to hit the B-70 with rockets" and requested the B-70 be downgraded to "a bare minimum research and development program" at $200 million for fiscal year 1960 (equivalent to $ billion today). President Eisenhower responded that the reconnaissance and strike mission was "crazy" since the nuclear mission was to attack known production and military complexes, and emphasized that he saw no need for the B-70 since the ICBM is "a cheaper, more effective way of doing the same thing". Eisenhower also identified that the B-70 would not be in manufacturing until "eight to ten years from now" and "said he thought we were talking about bows and arrows at a time of gunpowder when we spoke of bombers in the missile age". In December 1959 the Air Force announced the B-70 project would be cut to a single prototype, and most of the planned B-70 subsystems would no longer be developed.


title: North American XB-70 Valkyrie

text: Then interest increased due to the politics of presidential campaign of 1960. A central plank of John F. Kennedy's campaign was that Eisenhower and the Republicans were weak on defense, and pointed to the B-70 as an example. He told a San Diego audience near NAA facilities, "I endorse wholeheartedly the B-70 manned aircraft." Kennedy also made similar campaign claims regarding other aircraft: near the Seattle Boeing plant he affirmed the need for B-52s and in Fort Worth he praised the B-58.


title: North American XB-70 Valkyrie

text: The Air Force changed the program to full weapon development and awarded a contract for an XB-70 prototype and 11 YB-70s in August 1960. In November 1960, the B-70 program received a $265 million (equivalent to $ billion today) appropriation from Congress for FY 1961. Nixon, trailing in his home state of California, also publicly endorsed the B-70, and on 30 October Eisenhower helped the Republican campaign with a pledge of an additional $155 million ($ billion today) for the B-70 development program.


title: North American XB-70 Valkyrie

text: On taking office in January 1961, Kennedy was informed that the missile gap was an illusion. On 28 March 1961, after $800 million (equivalent to $ billion today) had been spent on the B-70 program, Kennedy canceled the project as "unnecessary and economically unjustifiable" because it "stood little chance of penetrating enemy defenses successfully." Instead, Kennedy recommended "the B-70 program be carried forward essentially to explore the problem of flying at three times the speed of sound with an airframe potentially useful as a bomber." After Congress approved $290 million ($ billion today) of B-70 "add-on" funds to the President's 12 May 1960 modified FY 1961 budget, the Administration decided on a "Planned Usage" of only $100 million ($ million today) of these funds. The Department of Defense subsequently presented data to Congress that the B-70 would add little performance for the high cost.


title: North American XB-70 Valkyrie

text: However, after becoming the new Air Force Chief of Staff in July 1961, Curtis LeMay increased his B-70 advocacy, including interviews for August "Reader's Digest" and November "Aviation Week" articles, and allowing a 25 February General Electric tour at which the press was provided artist conceptions of, and other info about, the B-70. Congress had also continued B-70 appropriations in an effort to resurrect bomber development. After Secretary of Defense Robert McNamara explained again to the House Armed Services Committee (HASC) on 24 January 1962 that the B-70 was unjustifiable, LeMay subsequently argued for the B-70 to both the House and Senate committees—and was chastised by McNamara on 1 March. By 7 March 1962, the HASC, 21 of whose members had B-70 work in their districts, had written an appropriations bill to "direct"—by law—the Executive Branch to use all of the nearly $500 million (equivalent to $ billion today) appropriated for the RS-70 (see Variants). McNamara was unsuccessful with an address to the HASC on 14 March, but a 19 March 1962 11th hour White House Rose Garden agreement between Kennedy and HASC chairman Carl Vinson retracted the bill's language and the bomber remained canceled.


title: North American XB-70 Valkyrie

text: The XB-70s were intended to be used for the advanced study of aerodynamics, propulsion, and other subjects related to large supersonic transports. The crew was reduced to only the two pilots, as a navigator and a bombardier were not needed for this research role. The production order was reduced to three prototypes in March 1961 with the third aircraft to incorporate improvements from the previous prototype. The order was later reduced to two experimental XB-70As, named Air Vehicle 1 and 2 (AV-1 and AV-2). XB-70 No. 1 was completed on 7May 1964, and rolled out on 11May 1964 at Palmdale, California. One report stated "nothing like it existed anywhere". AV-2 was completed on 15 October 1964. The manufacture of the third prototype (AV-3) was canceled in July 1964 before completion. The first XB-70 carried out its maiden flight in September 1964 and many more test flights followed.


title: North American XB-70 Valkyrie

text: The data from the XB-70 test flights and aerospace materials development were used in the later B-1 bomber program, the American supersonic transport (SST) program, and via espionage, the Soviet Union's Tupolev Tu-144 SST program. The development of the Lockheed U-2 and the SR-71 Blackbird reconnaissance aircraft, as well as the XB-70, prompted Soviet aerospace engineers to design and develop their high-altitude and high-speed MiG-25 interceptor.


title: North American XB-70 Valkyrie

text: The Valkyrie was designed to be a high-altitude Mach 3 bomber with six engines. Harrison Storms shaped the aircraft with a canard surface and a delta wing, which was built largely of stainless steel, sandwiched honeycomb panels, and titanium. The XB-70 was designed to use supersonic technologies developed for the Mach 3 SM-64 Navaho, as well as a modified form of the Navaho's inertial guidance system.


title: North American XB-70 Valkyrie

text: The XB-70 used compression lift, which resulted from a shock wave generated by the leading edge of the engine intake splitter below the apex of the wing. At Mach 3 cruising speed, the shock wave is bent back about 65 degrees and the wing is superimposed on the shock system which has a pressure 40 pounds per square foot higher under the aircraft than in front of the shock. The compression lift provided five percent of the total lift. Camber was added to the wing leading edge inboard of the folding tips to improve subsonic handling and reduce supersonic drag. The outer portions of the wings were hinged to pivot downward by 65 degrees, acting as a type of variable-geometry wingtip device. This increased the aircraft's directional stability at supersonic speeds, shifted the center of pressure to a more favorable position at high speeds, and caused the shock originating at the intake splitter to reflect from the vertical tip surface giving additional compression lift.


title: North American XB-70 Valkyrie

text: Like a number of other delta-wing aircraft designed for supersonic speeds (Concorde, Tu-144, FD2), the Valkyrie needed a feature to improve the pilot's view during nose-high low-speed flight and on the ground. An outer windshield and ramp, which could be lowered, was provided enabling viewing through the fixed cockpit windshield. With the ramp raised into its high-speed position, the forebody was more streamlined. Rain removal and windshield anti-ice was accomplished by utilizing bleed air from the engines. The lower forward section included a radar bay, and production machines were to be equipped with a refueling receptacle on the upper surface of the forward fuselage.


title: North American XB-70 Valkyrie

text: The XB-70 was equipped with six General Electric YJ93-GE-3 turbojet engines, which used JP-6 jet fuel, specially formulated for the mission requirements. The engine was stated to be in the "30,000-pound class", but actually produced with afterburner and without afterburner. The Valkyrie used fuel for cooling; it was pumped through heat exchangers before reaching the engines. To reduce the likelihood of autoignition, nitrogen was injected into the JP-6 during refueling, and the "fuel pressurization and inerting system" vaporized a supply of liquid nitrogen to fill the fuel tank vent space and maintain tank pressure.


title: North American XB-70 Valkyrie

text: The XB-70's maiden flight was on 21 September 1964. In the first flight test, between Palmdale and Edwards AFB, one engine had to be shut down shortly after take-off, and an undercarriage malfunction warning meant that the flight was flown with the undercarriage down as a precaution, limiting speed to – about half that planned. During landing, the rear wheels of the port side main gear locked, the tires ruptured, and a fire started.


title: North American XB-70 Valkyrie

text: The Valkyrie first became supersonic (Mach 1.1) on the third test flight on 12 October 1964, and flew above Mach 1 for 40 minutes during the following flight on 24 October. The wing tips were also lowered partially in this flight. XB-70 No. 1 surpassed Mach 3 on 14 October 1965 by reaching Mach 3.02 at . The first aircraft was found to suffer from weaknesses in the honeycomb panels, primarily due to inexperience with fabrication and quality control of this new material. On two occasions, honeycomb panels failed and were torn off during supersonic flight, necessitating a Mach 2.5 limit being placed on the aircraft.


title: North American XB-70 Valkyrie

text: The deficiencies discovered on AV-1 were almost completely solved on the second XB-70, which first flew on 17 July 1965. On 3 January 1966, XB-70 No. 2 attained a speed of Mach 3.05 while flying at . AV-2 reached a top speed of Mach 3.08 and maintained it for 20 minutes on 12 April 1966. On 19 May 1966, AV-2 reached Mach 3.06 and flew at Mach 3 for 32 minutes, covering in 91 minutes of total flight.


title: North American XB-70 Valkyrie

text: A joint NASA/USAF research program was conducted from 3 November 1966 to 31 January 1967 for measuring the intensity and signature of sonic booms for the National Sonic Boom Program. Testing was planned to cover a range of sonic boom overpressures on the ground similar to but higher than those anticipated from the proposed American SST. In 1966, AV-2 was selected for the program and was outfitted with test sensors. It flew the first sonic boom test on 6 June 1966, attaining a speed of Mach 3.05 at . Two days later, AV-2 crashed following a mid-air collision with an F-104 while flying in a multi-aircraft formation. Sonic boom and later testing continued with XB-70A #1.


title: North American XB-70 Valkyrie

text: The second flight research program (NASA NAS4-1174) investigated "control of structural dynamics" from 25 April 1967 through the XB-70's last flight in 1969. At high altitude and high speed, the XB-70A experienced unwanted changes in altitude. NASA testing from June 1968 included two small vanes on the nose of AV-1 for measuring the response of the aircraft's stability augmentation system. AV-1 flew a total of 83 flights.


title: North American XB-70 Valkyrie

text: The XB-70's last supersonic flight took place on 17 December 1968. On 4 February 1969, AV-1 took its final flight to Wright-Patterson Air Force Base for museum display (now the National Museum of the United States Air Force). Flight data was collected on this subsonic trip. North American Rockwell completed a four-volume report on the B-70 that was published by NASA in April 1972.


title: North American XB-70 Valkyrie

text: On 7 May 1965, a three-foot piece of the apex of the wing broke off in flight and caused extensive damage to five of the six engines. They were sent to GE and repaired. The sixth engine was inspected and re-installed in the aircraft.


title: North American XB-70 Valkyrie

text: On 14 October 1965, AV-1 surpassed Mach 3, but heat and stress damaged the honeycomb panels, leaving of the leading edge of the left wing missing. The first aircraft was limited to Mach 2.5 afterwards.


title: North American XB-70 Valkyrie

text: On 8 June 1966, XB-70A No. 2 was in close formation with four other aircraft (an F-4 Phantom, an F-5, a T-38 Talon, and an F-104 Starfighter) for a photoshoot at the behest of General Electric, manufacturer of the engines of all five aircraft. After the photoshoot, the F-104 drifted into the XB-70's right wingtip, flipped and rolled inverted over the top of the Valkyrie, before striking the bomber's vertical stabilizers and left wing. The F-104 then exploded, destroying the Valkyrie's vertical stabilizers and damaging its left wing. Despite the loss of both vertical stabilizers and damage to the wings, the Valkyrie flew straight for 16 seconds before it entered an uncontrollable spin and crashed north of Barstow, California. NASA Chief Test Pilot Joe Walker (F-104 pilot) and Carl Cross (XB-70 co-pilot) were killed. Al White (XB-70 pilot) ejected, sustaining serious injuries, including the crushing of his arm by the closing clamshell-like escape crew capsule moments prior to ejection.


title: North American XB-70 Valkyrie

text: The USAF summary report of the accident investigation stated that, given the position of the F-104 relative to the XB-70, Walker, the F-104 pilot, would not have been able to see the XB-70's wing, except by uncomfortably looking back over his left shoulder. The report said that it was likely that Walker maintained his position by looking at the fuselage of the XB-70, forward of his position. The F-104 was estimated to be to the side of the fuselage of the XB-70 and below. The report concluded that from that position, without appropriate sight cues, Walker was unable to properly perceive his motion relative to the Valkyrie, leading to his aircraft drifting into the XB-70's wing. The accident investigation also pointed to the wake vortex from the XB-70's right wingtip as the reason for the F-104's sudden roll over and into the bomber.


title: North American XB-70 Valkyrie

text: Valkyrie AV-1 (AF Ser. No. 62-0001) is on display at the National Museum of the United States Air Force at Wright-Patterson AFB near Dayton, Ohio. The aircraft was flown to the museum on 4 February 1969, following the conclusion of the XB-70 testing program. The Valkyrie became the museum's signature aircraft, appearing on Museum letterhead, and even appearing as the chief design feature for the Museum's restaurant, the "Valkyrie Cafe". In 2011, the XB-70 was on display in the museum's Research & Development Hangar alongside other experimental aircraft. After completion of the fourth hangar at the museum's main campus, the XB-70 was moved there in late October 2015.


title: Transcendentalism

text: Transcendentalism is a philosophical movement that developed in the late 1820s and 1830s in New England. A core belief is in the inherent goodness of people and nature, and while society and its institutions have corrupted the purity of the individual, people are at their best when truly "self-reliant" and independent. Transcendentalists saw divine experience inherent in the everyday, rather than believing in a distant heaven. Transcendentalists saw physical and spiritual phenomena as part of dynamic processes rather than discrete entities.


title: Transcendentalism

text: Transcendentalism is one of the first philosophical currents that emerged in the United States; it is therefore a key early point in the history of American philosophy. Emphasizing subjective intuition over objective empiricism, its adherents believe that individuals are capable of generating completely original insights with little attention and deference to past masters. It arose as a reaction, to protest against the general state of intellectualism and spirituality at the time. The doctrine of the Unitarian church as taught at Harvard Divinity School was closely related.


title: Transcendentalism

text: Transcendentalism emerged from "English and German Romanticism, the Biblical criticism of Johann Gottfried Herder and Friedrich Schleiermacher, the skepticism of David Hume", and the transcendental philosophy of Immanuel Kant and German idealism. Perry Miller and Arthur Versluis regard Emanuel Swedenborg and Jakob Böhme as pervasive influences on transcendentalism. It was also strongly influenced by Hindu texts on philosophy of the mind and spirituality, especially the Upanishads.


title: Transcendentalism

text: Transcendentalism is closely related to Unitarianism, a religious movement in Boston in the early nineteenth century. It started to develop after Unitarianism took hold at Harvard University, following the elections of Henry Ware as the Hollis Professor of Divinity in 1805 and of John Thornton Kirkland as President in 1810. Transcendentalism was not a rejection of Unitarianism; rather, it developed as an organic consequence of the Unitarian emphasis on free conscience and the value of intellectual reason. The transcendentalists were not content with the sobriety, mildness, and calm rationalism of Unitarianism. Instead, they longed for a more intense spiritual experience. Thus, transcendentalism was not born as a counter-movement to Unitarianism, but as a parallel movement to the very ideas introduced by the Unitarians.


title: Transcendentalism

text: Transcendentalism became a coherent movement and a sacred organization with the founding of the Transcendental Club in Cambridge, Massachusetts, on September 12, 1836, by prominent New England intellectuals, including George Putnam (Unitarian minister), Ralph Waldo Emerson, and Frederic Henry Hedge. Other members of the club included Amos Bronson Alcott, Orestes Brownson, Theodore Parker, Henry David Thoreau, William Henry Channing, James Freeman Clarke, Christopher Pearse Cranch, Convers Francis, Sylvester Judd, and Jones Very. Female members included Sophia Ripley, Margaret Fuller, Elizabeth Peabody, Ellen Sturgis Hooper, and Caroline Sturgis Tappan. From 1840, the group frequently published in their journal "The Dial", along with other venues.


title: Transcendentalism

text: By the late 1840s, Emerson believed that the movement was dying out, and even more so after the death of Margaret Fuller in 1850. "All that can be said", Emerson wrote, "is that she represents an interesting hour and group in American cultivation". There was, however, a second wave of transcendentalists later in the 19th century, including Moncure Conway, Octavius Brooks Frothingham, Samuel Longfellow and Franklin Benjamin Sanborn. Notably, the transcendence of the spirit, most often evoked by the poet's prosaic voice, is said to endow in the reader a sense of purpose. This is the underlying theme in the majority of transcendentalist essays and papers—all of which are centered on subjects which assert a love for individual expression. The group was mostly made up of struggling aesthetes, the wealthiest among them being Samuel Gray Ward, who, after a few contributions to "The Dial", focused on his banking career.


title: Transcendentalism

text: Transcendentalists are strong believers in the power of the individual. It is primarily concerned with personal freedom. Their beliefs are closely linked with those of the Romantics, but differ by an attempt to embrace or, at least, to not oppose the empiricism of science.


title: Transcendentalism

text: Transcendentalists desire to ground their religion and philosophy in principles based upon the German Romanticism of Johann Gottfried Herder and Friedrich Schleiermacher. Transcendentalism merged "English and German Romanticism, the Biblical criticism of Herder and Schleiermacher, the skepticism of Hume", and the transcendental philosophy of Immanuel Kant (and of German idealism more generally), interpreting Kant's "a priori" categories as "a priori" knowledge. Early transcendentalists were largely unacquainted with German philosophy in the original and relied primarily on the writings of Thomas Carlyle, Samuel Taylor Coleridge, Victor Cousin, Germaine de Staël, and other English and French commentators for their knowledge of it. The transcendental movement can be described as an American outgrowth of English Romanticism.


title: Transcendentalism

text: Transcendentalists believe that society and its institutions—particularly organized religion and political parties—corrupt the purity of the individual. They have faith that people are at their best when truly self-reliant and independent. It is only from such real individuals that true community can form.


title: Transcendentalism

text: Even with this necessary individuality, transcendentalists also believe that all people are outlets for the "Over-Soul". Because the Over-Soul is one, this unites all people as one being. Emerson alludes to this concept in the introduction of the "American Scholar" address, "that there is One Man, - present to all particular men only partially, or through one faculty; and that you must take the whole society to find the whole man". Such an ideal is in harmony with Transcendentalist individualism, as each person is empowered to behold within him or herself a piece of the divine Over-Soul.


title: Transcendentalism

text: In recent years there has been a distinction made between individuality and individualism. Both advocate the unique capacity of the individual. Yet individualism is decidedly anti-government, whereas individuality sees all facets of society necessary, or at least acceptable for the development of the true individualistic person. Whether the Transcendentalists believed in individualism or individuality remains to be determined. Whitman embraced all facets of life, which seems more like individuality, which is more in tune with what the Indian spiritual tradition advocates; i.e. the True Individual, the yogic attainment of true individuality.


title: Transcendentalism

text: While firmly rooted in the western philosophical traditions of Platonism, Neoplatonism, and German idealism, Transcendentalism was also directly influenced by Indian religions. Thoreau in "Walden" spoke of the Transcendentalists' debt to Indian religions directly:


title: Transcendentalism

text: In 1844, the first English translation of the Lotus Sutra was included in "The Dial", a publication of the New England Transcendentalists, translated from French by Elizabeth Palmer Peabody.


title: Transcendentalism

text: Transcendentalists differ in their interpretations of the practical aims of will. Some adherents link it with utopian social change; Brownson, for example, connected it with early socialism, but others consider it an exclusively individualist and idealist project. Emerson believed the latter. In his 1842 lecture "The Transcendentalist", he suggested that the goal of a purely transcendental outlook on life was impossible to attain in practice:


title: Transcendentalism

text: Transcendentalists have a deep gratitude and appreciation for nature, not only for aesthetic purposes, but also as a tool to observe and understand the structured inner workings of the natural world. Emerson emphasizes the Transcendental beliefs in the holistic power of the natural landscape in "Nature:"In the woods, we return to reason and faith. There I feel that nothing can befall me in life, — no disgrace, no calamity, (leaving me my eyes,) which nature cannot repair. Standing on the bare ground, — my head bathed by the blithe air, and uplifted into infinite space, — all mean egotism vanishes. I become a transparent eye-ball; I am nothing; I see all; the currents of the Universal Being circulate through me; I am part or particle of God.


title: Transcendentalism

text: The conservation of an undisturbed natural world is also extremely important to the Transcendentalists. The idealism that is a core belief of Transcendentalism results in an inherent skepticism of capitalism, westward expansion, and industrialization. As early as 1843, in "Summer on the Lakes," Margaret Fuller noted that "the noble trees are gone already from this island to feed this caldron", and in 1854, in "Walden," Thoreau regards the trains which are beginning to spread across America's landscape as a "winged horse or fiery dragon" that "sprinkle[s] all the restless men and floating merchandise in the country for seed".


title: Transcendentalism

text: Transcendentalism is, in many aspects, the first notable American intellectual movement. It has inspired succeeding generations of American intellectuals, as well as some literary movements.


title: Transcendentalism

text: Transcendentalism influenced the growing movement of "Mental Sciences" of the mid-19th century, which would later become known as the New Thought movement. New Thought considers Emerson its intellectual father. Emma Curtis Hopkins ("the teacher of teachers"), Ernest Holmes (founder of Religious Science), Charles and Myrtle Fillmore (founders of Unity), and Malinda Cramer and Nona L. Brooks (founders of Divine Science) were all greatly influenced by Transcendentalism.


title: Transcendentalism

text: Transcendentalism is also influenced by Hinduism. Ram Mohan Roy (1772–1833), the founder of the Brahmo Samaj, rejected Hindu mythology, but also the Christian trinity. He found that Unitarianism came closest to true Christianity, and had a strong sympathy for the Unitarians, who were closely connected to the Transcendentalists. Ram Mohan Roy founded a missionary committee in Calcutta, and in 1828 asked for support for missionary activities from the American Unitarians. By 1829, Roy had abandoned the Unitarian Committee, but after Roy's death, the Brahmo Samaj kept close ties to the Unitarian Church, who strove towards a rational faith, social reform, and the joining of these two in a renewed religion. Its theology was called "neo-Vedanta" by Christian commentators, and has been highly influential in the modern popular understanding of Hinduism, but also of modern western spirituality, which re-imported the Unitarian influences in the disguise of the seemingly age-old Neo-Vedanta.


title: Transcendentalism

text: Major figures in the transcendentalist movement were Ralph Waldo Emerson, Henry David Thoreau, Margaret Fuller, and Amos Bronson Alcott. Some other prominent transcendentalists included Louisa May Alcott, Charles Timothy Brooks, Orestes Brownson, William Ellery Channing, William Henry Channing, James Freeman Clarke, Christopher Pearse Cranch, John Sullivan Dwight, Convers Francis, William Henry Furness, Frederic Henry Hedge, Sylvester Judd, Theodore Parker, Elizabeth Palmer Peabody, George Ripley, Thomas Treadwell Stone, Jones Very, and Walt Whitman.


title: Transcendentalism

text: Early in the movement's history, the term "Transcendentalists" was used as a pejorative term by critics, who were suggesting their position was beyond sanity and reason. Nathaniel Hawthorne wrote a novel, "The Blithedale Romance" (1852), satirizing the movement, and based it on his experiences at Brook Farm, a short-lived utopian community founded on transcendental principles.


title: Transcendentalism

text: Edgar Allan Poe wrote a story, "Never Bet the Devil Your Head" (1841), in which he embedded elements of deep dislike for transcendentalism, calling its followers "Frogpondians" after the pond on Boston Common. The narrator ridiculed their writings by calling them "metaphor-run" lapsing into "mysticism for mysticism's sake", and called it a "disease". The story specifically mentions the movement and its flagship journal "The Dial", though Poe denied that he had any specific targets. In Poe's essay "The Philosophy of Composition" (1846), he offers criticism denouncing "the excess of the suggested meaning... which turns into prose (and that of the very flattest kind) the so-called poetry of the so-called transcendentalists".


title: Gunshot wound

text: A gunshot wound (GSW) is a penetrating injury caused by a projectile (e.g. a bullet) from a gun (typically firearm or air gun). Damages may include bleeding, bone fractures, organ damage, wound infection, loss of the ability to move part of the body and, in more severe cases, death. Damage depends on the part of the body hit, the path the bullet follows through the body, and the type and speed of the bullet. Long-term complications can include lead poisoning and post-traumatic stress disorder (PTSD).


title: Gunshot wound

text: Factors that determine rates of gun violence vary by country. These factors may include the illegal drug trade, easy access to firearms, substance misuse including alcohol, mental health problems, firearm laws, social attitudes, economic differences and occupations such as being a police officer. Where guns are more common, altercations more often end in death.


title: Gunshot wound

text: Before management begins it should be verified the area is safe. This is followed by stopping major bleeding, then assessing and supporting the airway, breathing, and circulation. Firearm laws, particularly background checks and permit to purchase, decrease the risk of death from firearms. Safer firearm storage may decrease the risk of firearm-related deaths in children.


title: Gunshot wound

text: In 2015, about a million gunshot wounds occurred from interpersonal violence. In 2016, firearms resulted in 251,000 deaths globally, up from 209,000 in 1990. Of these deaths 161,000 (64%) were the result of assault, 67,500 (27%) were the result of suicide, and 23,000 (9%) were accidents. In the United States, guns resulted in about 40,000 deaths in 2017. Firearm-related deaths are most common in males between the ages of 20 to 24 years. Economic costs due to gunshot wounds have been estimated at US$140 billion a year in the United States.


title: Gunshot wound

text: Trauma from a gunshot wound varies widely based on the bullet, velocity, mass, entry point, trajectory, affected anatomy, and exit point. Gunshot wounds can be particularly devastating compared to other penetrating injuries because the trajectory and fragmentation of bullets can be unpredictable after entry. Moreover, gunshot wounds typically involve a large degree of nearby tissue disruption and destruction caused by the physical effects of the projectile correlated with the bullet velocity classification.


title: Gunshot wound

text: The immediate damaging effect of a gunshot wound is typically severe bleeding with the potential for hypovolemic shock, a condition characterized by inadequate delivery of oxygen to vital organs. In the case of traumatic hypovolemic shock, this failure of adequate oxygen delivery is due to blood loss, as blood is the means of delivering oxygen to the body's constituent parts. Devastating effects can result when a bullet strikes a vital organ such as the heart, lungs or liver, or damages a component of the central nervous system such as the spinal cord or brain.


title: Gunshot wound

text: Common causes of death following gunshot injury include bleeding, low oxygen caused by pneumothorax, catastrophic injury to the heart and major blood vessels, and damage to the brain or central nervous system. Non-fatal gunshot wounds frequently have mild to severe long-lasting effects, typically some form of major disfigurement such as amputation because of a severe bone fracture and may cause permanent disability. A sudden blood gush may take effect immediately from a gunshot wound if a bullet directly damages larger blood vessels, especially arteries.


title: Gunshot wound

text: The degree of tissue disruption caused by a projectile is related to the cavitation the projectile creates as it passes through tissue. A bullet with sufficient energy will have a cavitation effect in addition to the penetrating track injury. As the bullet passes through the tissue, initially crushing then lacerating, the space left forms a cavity; this is called the permanent cavity. Higher-velocity bullets create a pressure wave that forces the tissues away, creating not only a permanent cavity the size of the caliber of the bullet but a temporary cavity or secondary cavity, which is often many times larger than the bullet itself. The temporary cavity is the radial stretching of tissue around the bullet's wound track, which momentarily leaves an empty space caused by high pressures surrounding the projectile that accelerate material away from its path. The extent of cavitation, in turn, is related to the following characteristics of the projectile:


title: Gunshot wound

text: Gunshot wounds are classified according to the speed of the projectile using the Gustilo open fracture classification:


title: Gunshot wound

text: Low velocity wounds are typical of small caliber handguns and display wound patterns like Gustilo Anderson Type 1 or 2 wounds


title: Gunshot wound

text: These are more typical of shotgun blasts or higher caliber handguns like magnums. The risk of infection from these types of wounds can vary depending on the type and pattern of bullets fired as well as the distance from the firearm.


title: Gunshot wound

text: Usually caused by powerful assault or hunting rifles and usually display wound pattern similar to Gustilo Anderson Type 3 wounds. The risk of infection is especially high due to the large area of injury and destroyed tissue.


title: Gunshot wound

text: Bullets from handguns are sometimes less than but with modern pistol loads, they usually are slightly above , while bullets from most modern rifles exceed . One recently developed class of firearm projectiles is the hyper-velocity bullet, such cartridges are usually either wildcats made for achieving such high speed or purpose-built factory ammunition with the same goal in mind. Examples of hyper velocity cartridges include the .220 Swift, .17 Remington and .17 Mach IV cartridges. The US military commonly uses 5.56mm bullets, which have a relatively low mass as compared with other bullets (40-62 grains); however, the speed of these bullets is relatively fast (Approximately , placing them in the high velocity category). As a result, they produce a larger amount of kinetic energy, which is transmitted to the tissues of the target. However, one must remember that high kinetic energy does not necessarily equate to high stopping power, as incapacitation usually results from remote wounding effects such as bleeding, rather than raw energy transfer. High energy does indeed result in more tissue disruption, which plays a role in incapacitation, but other factors such as wound size and shot placement play as big of, if not a bigger role in stopping power and thus, effectiveness. Muzzle velocity does not consider the effect of aerodynamic drag on the flight of the bullet for the sake of ease of comparison.


title: Gunshot wound

text: Medical organizations in the United States recommend a criminal background check being held before a person buys a gun and that a person who has convictions for crimes of violence should not be permitted to buy a gun. Safe storage of firearms is recommended, as well as better mental health care and removal of guns from those at risk of suicide. In an effort to prevent mass shootings greater regulations on guns that can rapidly fire many bullets is recommended.


title: Gunshot wound

text: Initial assessment for a gunshot wound is approached in the same way as other acute trauma using the advanced trauma life support (ATLS) protocol. These include:


title: Gunshot wound

text: Depending on the extent of injury, management can range from urgent surgical intervention to observation. As such, any history from the scene such as gun type, shots fired, shot direction and distance, blood loss on scene, and pre-hospital vitals signs can be very helpful in directing management. Unstable people with signs of bleeding that cannot be controlled during the initial evaluation require immediate surgical exploration in the operating room. Otherwise, management protocols are generally dictated by anatomic entry point and anticipated trajectory.


title: Gunshot wound

text: A gunshot wound to the neck can be particularly dangerous because of the high number of vital anatomical structures contained within a small space. The neck contains the larynx, trachea, pharynx, esophagus, vasculature (carotid, subclavian, and vertebral arteries; jugular, brachiocephalic, and vertebral veins; thyroid vessels), and nervous system anatomy (spinal cord, cranial nerves, peripheral nerves, sympathetic chain, brachial plexus). Gunshots to the neck can thus cause severe bleeding, airway compromise, and nervous system injury.


title: Gunshot wound

text: Initial assessment of a gunshot wound to the neck involves non-probing inspection of whether the injury is a penetrating neck injury (PNI), classified by violation of the platysma muscle. If the platysma is intact, the wound is considered superficial and only requires local wound care. If the injury is a PNI, surgery should be consulted immediately while the case is being managed. Of note, wounds should not be explored on the field or in the emergency department given the risk of exacerbating the wound.


title: Gunshot wound

text: Due to the advances in diagnostic imaging, management of PNI has been shifting from a "zone-based" approach, which uses anatomical site of injury to guide decisions, to a "no-zone" approach which uses a symptom-based algorithm. The no-zone approach uses a hard signs and imaging system to guide next steps. Hard signs include airway compromise, unresponsive shock, diminished pulses, uncontrolled bleeding, expanding hematoma, bruits/thrill, air bubbling from wound or extensive subcutaneous air, stridor/hoarseness, neurological deficits. If any hard signs are present, immediate surgical exploration and repair is pursued alongside airway and bleeding control. If there are no hard signs, the person receives a multi-detector CT angiography for better diagnosis. A directed angiography or endoscopy may be warranted in a high-risk trajectory for the gunshot. A positive finding on CT leads to operative exploration. If negative, the person may be observed with local wound care.


title: Gunshot wound

text: Important anatomy in the chest includes the chest wall, ribs, spine, spinal cord, intercostal neurovascular bundles, lungs, bronchi, heart, aorta, major vessels, esophagus, thoracic duct, and diaphragm. Gunshots to the chest can thus cause severe bleeding (hemothorax), respiratory compromise (pneumothorax, hemothorax, pulmonary contusion, tracheobronchial injury), cardiac injury (pericardial tamponade), esophageal injury, and nervous system injury.


title: Gunshot wound

text: Initial workup as outlined in the Workup section is particularly important with gunshot wounds to the chest because of the high risk for direct injury to the lungs, heart, and major vessels. Important notes for the initial workup specific for chest injuries are as follows. In people with pericardial tamponade or tension pneumothorax, the chest should be evacuated or decompressed if possible prior to attempting tracheal intubation because the positive pressure ventilation can cause hypotention or cardiovascular collapse. Those with signs of a tension pneumothorax (asymmetric breathing, unstable blood flow, respiratory distress) should immediately receive a chest tube (> French 36) or needle decompression if chest tube placement is delayed. FAST exam should include extended views into the chest to evaluate for hemopericardium, pneumothorax, hemothorax, and peritoneal fluid.


title: Gunshot wound

text: Those with cardiac tamponade, uncontrolled bleeding, or a persistent air leak from a chest tube all require surgery. Cardiac tamponade can be identified on FAST exam. Blood loss warranting surgery is 1–1.5 L of immediate chest tube drainage or ongoing bleeding of 200-300 mL/hr. Persistent air leak is suggestive of tracheobronchial injury which will not heal without surgical intervention. Depending on the severity of the person's condition and if cardiac arrest is recent or imminent, the person may require surgical intervention in the emergency department, otherwise known as an emergency department thoracotomy (EDT).


title: Gunshot wound

text: However, not all gunshot to the chest require surgery. Asymptomatic people with a normal chest X-ray can be observed with a repeat exam and imaging after 6 hours to ensure no delayed development of pneumothorax or hemothorax. If a person only has a pneumothorax or hemothorax, a chest tube is usually sufficient for management unless there is large volume bleeding or persistent air leak as noted above. Additional imaging after initial chest X-ray and ultrasound can be useful in guiding next steps for stable people. Common imaging modalities include chest CT, formal echocardiography, angiography, esophagoscopy, esophagography, and bronchoscopy depending on the signs and symptoms.


title: Gunshot wound

text: Important anatomy in the abdomen includes the stomach, small bowel, colon, liver, spleen, pancreas, kidneys, spine, diaphragm, descending aorta, and other abdominal vessels and nerves. Gunshots to the abdomen can thus cause severe bleeding, release of bowel contents, peritonitis, organ rupture, respiratory compromise, and neurological deficits.


title: Gunshot wound

text: The most important initial evaluation of a gunshot wound to the abdomen is whether there is uncontrolled bleeding, inflammation of the peritoneum, or spillage of bowel contents. If any of these are present, the person should be transferred immediately to the operating room for laparotomy. If it is difficult to evaluate for those indications because the person is unresponsive or incomprehensible, it is up to the surgeon's discretion whether to pursue laparotomy, exploratory laparoscopy, or alternative investigative tools.


title: Gunshot wound

text: Although all people with abdominal gunshot wounds were taken to the operating room in the past, practice has shifted in recent years with the advances in imaging to non-operative approaches in more stable people. If the person's vital signs are stable without indication for immediate surgery, imaging is done to determine the extent of injury. Ultrasound (FAST) and help identify intra-abdominal bleeding and X-rays can help determine bullet trajectory and fragmentation. However, the best and preferred mode of imaging is high-resolution multi-detector CT (MDCT) with IV, oral, and sometimes rectal contrast. Severity of injury found on imaging will determine whether the surgeon takes an operative or close observational approach.


title: Gunshot wound

text: Diagnostic peritoneal lavage (DPL) has become largely obsolete with the advances in MDCT, with use limited to centers without access to CT to guide requirement for urgent transfer for operation.


title: Gunshot wound

text: The four main components of extremities are bones, vessels, nerves, and soft tissues. Gunshot wounds can thus cause severe bleeding, fractures, nerve deficits, and soft tissue damage. The Mangled Extremity Severity Score (MESS) is used to classify the severity of injury and evaluates for severity of skeletal and/or soft tissue injury, limb ischemia, shock, and age. Depending on the extent of injury, management can range from superficial wound care to limb amputation.


title: Gunshot wound

text: Vital sign stability and vascular assessment are the most important determinants of management in extremity injuries. As with other traumatic cases, those with uncontrolled bleeding require immediate surgical intervention. If surgical intervention is not readily available and direct pressure is insufficient to control bleeding, tourniquets or direct clamping of visible vessels may be used temporarily to slow active bleeding. People with hard signs of vascular injury also require immediate surgical intervention. Hard signs include active bleeding, expanding or pulsatile hematoma, bruit/thrill, absent distal pulses and signs of extremity ischemia.


title: Gunshot wound

text: For stable people without hard signs of vascular injury, an injured extremity index (IEI) should be calculated by comparing the blood pressure in the injured limb compared to an uninjured limb in order to further evaluate for potential vascular injury. If the IEI or clinical signs are suggestive of vascular injury, the person may undergo surgery or receive further imaging including CT angiography or conventional arteriography.


title: Gunshot wound

text: In addition to vascular management, people must be evaluated for bone, soft tissue, and nerve injury. Plain films can be used for fractures alongside CTs for soft tissue assessment. Fractures must be debrided and stabilized, nerves repaired when possible, and soft tissue debrided and covered. This process can often require multiple procedures over time depending on the severity of injury.


title: Gunshot wound

text: In 2015, about a million gunshot wounds occurred from interpersonal violence. Firearms, globally in 2016, resulted in 251,000 deaths up from 209,000 in 1990. Of these deaths 161,000 (64%) were the result of assault, 67,500 (27%) were the result of suicide, and 23,000 were accidents. Firearm related deaths are most common in males between the ages of 20 to 24 years.


title: Gunshot wound

text: The countries with the greatest number of deaths from firearms are Brazil, United States, Mexico, Colombia, Venezuela, Guatemala, Bahamas and South Africa which make up just over half the total. In the United States in 2015 about half of the 44,000 people who died by suicide did so with a gun.


title: Gunshot wound

text: As of 2016, the countries with the highest rates of gun violence per capita were El Salvador, Venezuela, and Guatemala with 40.3, 34.8, and 26.8 violent gun deaths per 100,000 people respectively. The countries with the lowest rates of were Singapore, Japan, and South Korea with 0.03, 0.04, and 0.05 violent gun deaths per 100,000 people respectively.


title: Gunshot wound

text: In 2016, about 893 people died due to gunshot wounds in Canada (2.1 per 100,000). About 80% were suicides, 12% were assaults, and 4% percent were an accident.


title: Gunshot wound

text: In 2017, there were 39,773 deaths in the United States as a result gunshot wounds. Of these 60% were suicides, 37% were homicides, 1.4% were by law enforcement, 1.2% were accidents, and 0.9% were from an unknown cause. This is up from 37,200 deaths in 2016 due to a gunshot wound (10.6 per 100,000). With respect to those that pertain to interpersonal violence, it had the 31st highest rate in the world with 3.85 deaths per 100,000 people in 2016. The majority of all homicides and suicides are firearm-related, and the majority of firearm-related deaths are the result of murder and suicide. When sorted by GDP, however, the United States has a much higher violent gun death rate compared to other developed countries, with over 10 times the number of firearms assault deaths than the next four highest GDP countries combined. Gunshot violence is the third most costly cause of injury and the fourth most expensive form of hospitalization in the United States.


title: Gunshot wound

text: Until the 1880s, the standard practice for treating a gunshot wound called for physicians to insert their unsterilized fingers into the wound to probe and locate the path of the bullet. Standard surgical theory such as opening abdominal cavities to repair gunshot wounds, germ theory, and Joseph Lister's technique for antiseptic surgery using diluted carbolic acid, had not yet been accepted as standard practice. For example, sixteen doctors attended to President James A. Garfield after he was shot in 1881, and most probed the wound with their fingers or dirty instruments. Historians agree that massive infection was a significant factor in Garfield's death.


title: Gunshot wound

text: At almost the same time, in Tombstone, Arizona Territory, on 13 July 1881, George E. Goodfellow performed the first laparotomy to treat an abdominal gunshot wound. Goodfellow pioneered the use of sterile techniques in treating gunshot wounds, washing the person's wound and his hands with lye soap or whisky, and his patient, unlike the President, recovered. He became America's leading authority on gunshot wounds and is credited as the United States' first civilian trauma surgeon.


title: Gunshot wound

text: Mid-nineteenth-century handguns such as the Colt revolvers used during the American Civil War had muzzle velocities of just 230–260 m/s and their powder and ball predecessors had velocities of 167 m/s or less. Unlike today's high-velocity bullets, nineteenth-century balls produced almost little or no cavitation and, being slower moving, they were liable to lodge in unusual locations at odds with their trajectory.


title: Gunshot wound

text: Wilhelm Röntgen's discovery of X-rays in 1895 led to the use of radiographs to locate bullets in wounded soldiers.