title: Block cipher mode of operation

text: A block cipher works on units of a fixed size (known as a "block size"), but messages come in a variety of lengths. So some modes (namely ECB and CBC) require that the final block be padded before encryption. Several padding schemes exist. The simplest is to add null bytes to the plaintext to bring its length up to a multiple of the block size, but care must be taken that the original length of the plaintext can be recovered; this is trivial, for example, if the plaintext is a C style string which contains no null bytes except at the end. Slightly more complex is the original DES method, which is to add a single one bit, followed by enough zero bits to fill out the block; if the message ends on a block boundary, a whole padding block will be added. Most sophisticated are CBC-specific schemes such as ciphertext stealing or residual block termination, which do not cause any extra ciphertext, at the expense of some additional complexity. Schneier and Ferguson suggest two possibilities, both simple: append a byte with value 128 (hex 80), followed by as many zero bytes as needed to fill the last block, or pad the last block with "n" bytes all with value "n".


title: Block cipher mode of operation

text: CFB, OFB and CTR modes do not require any special measures to handle messages whose lengths are not multiples of the block size, since the modes work by XORing the plaintext with the output of the block cipher. The last partial block of plaintext is XORed with the first few bytes of the last keystream block, producing a final ciphertext block that is the same size as the final partial plaintext block. This characteristic of stream ciphers makes them suitable for applications that require the encrypted ciphertext data to be the same size as the original plaintext data, and for applications that transmit data in streaming form where it is inconvenient to add padding bytes.


title: Block cipher mode of operation

text: A number of modes of operation have been designed to combine secrecy and authentication in a single cryptographic primitive. Examples of such modes are , , integrity-aware parallelizable mode (IAPM), OCB, EAX, CWC, CCM, and GCM. Authenticated encryption modes are classified as single-pass modes or double-pass modes. Some single-pass authenticated encryption algorithms, such as OCB mode, are encumbered by patents, while others were specifically designed and released in a way to avoid such encumberment.


title: Block cipher mode of operation

text: In addition, some modes also allow for the authentication of unencrypted associated data, and these are called AEAD (authenticated encryption with associated data) schemes. For example, EAX mode is a double-pass AEAD scheme while OCB mode is single-pass.


title: Block cipher mode of operation

text: Galois/counter mode (GCM) combines the well-known counter mode of encryption with the new Galois mode of authentication. The key feature is the ease of parallel computation of the Galois field multiplication used for authentication. This feature permits higher throughput than encryption algorithms.


title: Block cipher mode of operation

text: GCM is defined for block ciphers with a block size of 128 bits. Galois message authentication code (GMAC) is an authentication-only variant of the GCM which can form an incremental message authentication code. Both GCM and GMAC can accept initialization vectors of arbitrary length. GCM can take full advantage of parallel processing and implementing GCM can make efficient use of an instruction pipeline or a hardware pipeline. The CBC mode of operation incurs pipeline stalls that hamper its efficiency and performance.


title: Block cipher mode of operation

text: Like in CTR, blocks are numbered sequentially, and then this block number is combined with an IV and encrypted with a block cipher , usually AES. The result of this encryption is then XORed with the plaintext to produce the ciphertext. Like all counter modes, this is essentially a stream cipher, and so it is essential that a different IV is used for each stream that is encrypted.


title: Block cipher mode of operation

text: The ciphertext blocks are considered coefficients of a polynomial which is then evaluated at a key-dependent point , using finite field arithmetic. The result is then encrypted, producing an authentication tag that can be used to verify the integrity of the data. The encrypted text then contains the IV, ciphertext, and authentication tag.


title: Block cipher mode of operation

text: "Counter with cipher block chaining message authentication code" (counter with CBC-MAC; CCM) is an authenticated encryption algorithm designed to provide both authentication and confidentiality. CCM mode is only defined for block ciphers with a block length of 128 bits.


title: Block cipher mode of operation

text: SIV synthesizes an internal IV using the pseudorandom function S2V. S2V is a keyed hash is based on CMAC, and the input to the function is:


title: Block cipher mode of operation

text: SIV can support external nonce-based authenticated encryption, in which case one of the authenticated data fields is utilized for this purpose. RFC5297 specifies that for interoperability purposes the last authenticated data field should be used external nonce.


title: Block cipher mode of operation

text: Owing to the use of two keys, the authentication key K and encryption key K, naming schemes for SIV AEAD-variants may lead to some confusion; for example AEAD_AES_SIV_CMAC_256 refers to AES-SIV with two AES-128 keys and not AES-256.


title: Block cipher mode of operation

text: AES-GCM-SIV is a mode of operation for the Advanced Encryption Standard which provides similar performance to Galois/counter mode as well as misuse resistance in the event of the reuse of a cryptographic nonce. The construction is defined in RFC 8452.


title: Block cipher mode of operation

text: AES-GCM-SIV synthesizes the internal IV. It derives a hash of the additional authenticated data and plaintext using the POLYVAL Galois hash function. The hash is then encrypted an AES-key, and used as authentication tag and AES-CTR initialization vector.


title: Block cipher mode of operation

text: AES-GCM-SIV is an improvement over the very similarly named algorithm GCM-SIV, with a few very small changes (e.g. how AES-CTR is initialized), but which yields practical benefits to its security "This addition allows for encrypting up to 2 messages with the same key, compared to the significant limitation of only 2 messages that were allowed with GCM-SIV."


title: Block cipher mode of operation

text: Many modes of operation have been defined. Some of these are described below. The purpose of cipher modes is to mask patterns which exist in encrypted data, as illustrated in the description of the weakness of ECB.


title: Block cipher mode of operation

text: Different cipher modes mask patterns by cascading outputs from the cipher block or other globally deterministic variables into the subsequent cipher block. The inputs of the listed modes are summarized in the following table:


title: Block cipher mode of operation

text: The simplest (and not to be used anymore) of the encryption modes is the electronic codebook (ECB) mode (named after conventional physical codebooks). The message is divided into blocks, and each block is encrypted separately.


title: Block cipher mode of operation

text: The disadvantage of this method is a lack of diffusion. Because ECB encrypts identical plaintext blocks into identical ciphertext blocks, it does not hide data patterns well.


title: Block cipher mode of operation

text: A striking example of the degree to which ECB can leave plaintext data patterns in the ciphertext can be seen when ECB mode is used to encrypt a bitmap image which uses large areas of uniform color. While the color of each individual pixel is encrypted, the overall image may still be discerned, as the pattern of identically colored pixels in the original remains in the encrypted version.


title: Block cipher mode of operation

text: ECB mode can also make protocols without integrity protection even more susceptible to replay attacks, since each block gets decrypted in exactly the same way.


title: Block cipher mode of operation

text: Ehrsam, Meyer, Smith and Tuchman invented the cipher block chaining (CBC) mode of operation in 1976. In CBC mode, each block of plaintext is XORed with the previous ciphertext block before being encrypted. This way, each ciphertext block depends on all plaintext blocks processed up to that point. To make each message unique, an initialization vector must be used in the first block.


title: Block cipher mode of operation

text: CBC has been the most commonly used mode of operation. Its main drawbacks are that encryption is sequential (i.e., it cannot be parallelized), and that the message must be padded to a multiple of the cipher block size. One way to handle this last issue is through the method known as ciphertext stealing. Note that a one-bit change in a plaintext or initialization vector (IV) affects all following ciphertext blocks.


title: Block cipher mode of operation

text: Decrypting with the incorrect IV causes the first block of plaintext to be corrupt but subsequent plaintext blocks will be correct. This is because each block is XORed with the ciphertext of the previous block, not the plaintext, so one does not need to decrypt the previous block before using it as the IV for the decryption of the current one. This means that a plaintext block can be recovered from two adjacent blocks of ciphertext. As a consequence, decryption "can" be parallelized. Note that a one-bit change to the ciphertext causes complete corruption of the corresponding block of plaintext, and inverts the corresponding bit in the following block of plaintext, but the rest of the blocks remain intact. This peculiarity is exploited in different padding oracle attacks, such as POODLE.


title: Block cipher mode of operation

text: "Explicit initialization vectors" takes advantage of this property by prepending a single random block to the plaintext. Encryption is done as normal, except the IV does not need to be communicated to the decryption routine. Whatever IV decryption uses, only the random block is "corrupted". It can be safely discarded and the rest of the decryption is the original plaintext.


title: Block cipher mode of operation

text: The "propagating cipher block chaining" or "plaintext cipher-block chaining" mode was designed to cause small changes in the ciphertext to propagate indefinitely when decrypting, as well as when encrypting. In PCBC mode, each block of plaintext is XORed with both the previous plaintext block and the previous ciphertext block before being encrypted. Like with CBC mode, an initialization vector is used in the first block.


title: Block cipher mode of operation

text: Unlike CBC, decrypting PCBC with the incorrect IV (initialization vector) causes all blocks of plaintext to be corrupt.


title: Block cipher mode of operation

text: PCBC is used in Kerberos v4 and WASTE, most notably, but otherwise is not common. On a message encrypted in PCBC mode, if two adjacent ciphertext blocks are exchanged, this does not affect the decryption of subsequent blocks. For this reason, PCBC is not used in Kerberos v5.


title: Block cipher mode of operation

text: The "cipher feedback" (CFB) mode, in its simplest form uses the entire output of the block cipher. In this variation, it is very similar to CBC, makes a block cipher into a self-synchronizing stream cipher. CFB decryption in this variation is almost identical to CBC encryption performed in reverse:


title: Block cipher mode of operation

text: NIST SP800-38A defines CFB with a bit-width. "The CFB mode also requires an integer parameter, denoted s, such that 1 ≤ s ≤ b. In the specification of the CFB mode below, each plaintext segment (Pj) and ciphertext segment (Cj) consists of s bits. The value of s is sometimes incorporated into the name of the mode, e.g., the 1-bit CFB mode, the 8-bit CFB mode, the 64-bit CFB mode, or the 128-bit CFB mode."


title: Block cipher mode of operation

text: CFB-1 is considered self synchronizing and resilient to loss of ciphertext; "When the 1-bit CFB mode is used, then the synchronization is automatically restored b+1 positions after the inserted or deleted bit. For other values of s in the CFB mode, and for the other confidentiality modes in this recommendation, the synchronization must be restored externally." (NIST SP800-38A). I.e. 1-bit loss in a 128-bit-wide block cipher like AES will render 129 invalid bits before emitting valid bits.


title: Block cipher mode of operation

text: CFB may also self synchronize in some special cases other than those specified. For example, a one bit change in CFB-128 with an underlying 128 bit block cipher, will re-synchronize after two blocks. (However, CFB-128 etc. will not handle bit loss gracefully; a one-bit loss will cause the decryptor to lose alignment with the encryptor)


title: Block cipher mode of operation

text: Like CBC mode, changes in the plaintext propagate forever in the ciphertext, and encryption cannot be parallelized. Also like CBC, decryption can be parallelized.


title: Block cipher mode of operation

text: CFB, OFB and CTR share two advantages over CBC mode: the block cipher is only ever used in the encrypting direction, and the message does not need to be padded to a multiple of the cipher block size (though ciphertext stealing can also be used for CBC mode to make padding unnecessary).


title: Block cipher mode of operation

text: The "output feedback" (OFB) mode makes a block cipher into a synchronous stream cipher. It generates keystream blocks, which are then XORed with the plaintext blocks to get the ciphertext. Just as with other stream ciphers, flipping a bit in the ciphertext produces a flipped bit in the plaintext at the same location. This property allows many error-correcting codes to function normally even when applied before encryption.


title: Block cipher mode of operation

text: Each output feedback block cipher operation depends on all previous ones, and so cannot be performed in parallel. However, because the plaintext or ciphertext is only used for the final XOR, the block cipher operations may be performed in advance, allowing the final step to be performed in parallel once the plaintext or ciphertext is available.


title: Block cipher mode of operation

text: It is possible to obtain an OFB mode keystream by using CBC mode with a constant string of zeroes as input. This can be useful, because it allows the usage of fast hardware implementations of CBC mode for OFB mode encryption.


title: Block cipher mode of operation

text: Using OFB mode with a partial block as feedback like CFB mode reduces the average cycle length by a factor of 2 or more. A mathematical model proposed by Davies and Parkin and substantiated by experimental results showed that only with full feedback an average cycle length near to the obtainable maximum can be achieved. For this reason, support for truncated feedback was removed from the specification of OFB.


title: Block cipher mode of operation

text: Like OFB, counter mode turns a block cipher into a stream cipher. It generates the next keystream block by encrypting successive values of a "counter". The counter can be any function which produces a sequence which is guaranteed not to repeat for a long time, although an actual increment-by-one counter is the simplest and most popular. The usage of a simple deterministic input function used to be controversial; critics argued that "deliberately exposing a cryptosystem to a known systematic input represents an unnecessary risk". However, today CTR mode is widely accepted, and any problems are considered a weakness of the underlying block cipher, which is expected to be secure regardless of systemic bias in its input. Along with CBC, CTR mode is one of two block cipher modes recommended by Niels Ferguson and Bruce Schneier.


title: Block cipher mode of operation

text: CTR mode has similar characteristics to OFB, but also allows a random-access property during decryption. CTR mode is well suited to operate on a multi-processor machine, where blocks can be encrypted in parallel. Furthermore, it does not suffer from the short-cycle problem that can affect OFB.


title: Block cipher mode of operation

text: If the IV/nonce is random, then they can be combined with the counter using any invertible operation (concatenation, addition, or XOR) to produce the actual unique counter block for encryption. In case of a non-random nonce (such as a packet counter), the nonce and counter should be concatenated (e.g., storing the nonce in the upper 64 bits and the counter in the lower 64 bits of a 128-bit counter block). Simply adding or XORing the nonce and counter into a single value would break the security under a chosen-plaintext attack in many cases, since the attacker may be able to manipulate the entire IV–counter pair to cause a collision. Once an attacker controls the IV–counter pair and plaintext, XOR of the ciphertext with the known plaintext would yield a value that, when XORed with the ciphertext of the other block sharing the same IV–counter pair, would decrypt that block.


title: Block cipher mode of operation

text: Note that the nonce in this diagram is equivalent to the initialization vector (IV) in the other diagrams. However, if the offset/location information is corrupt, it will be impossible to partially recover such data due to the dependence on byte offset.


title: Block cipher mode of operation

text: "Error propagation" properties describe how a decryption behaves during bit errors, i.e. how error in one bit cascades to different decrypted bits.


title: Block cipher mode of operation

text: For modern authenticated encryption (AEAD) or protocols with message authentication codes chained in MAC-Then-Encrypt order, any bit error should completely abort decryption and must not generate any specific bit errors to decryptor. I.e. if decryption succeeded, there should not be any bit error. As such error propagation is less important subject in modern cipher modes than in traditional confidentiality-only modes.


title: Block cipher mode of operation

text: It might be observed, for example, that a one-block error in the transmitted ciphertext would result in a one-block error in the reconstructed plaintext for ECB mode encryption, while in CBC mode such an error would affect two blocks. Some felt that such resilience was desirable in the face of random errors (e.g., line noise), while others argued that error correcting increased the scope for attackers to maliciously tamper with a message.


title: Block cipher mode of operation

text: However, when proper integrity protection is used, such an error will result (with high probability) in the entire message being rejected. If resistance to random error is desirable, error-correcting codes should be applied to the ciphertext before transmission.


title: Block cipher mode of operation

text: Many more modes of operation for block ciphers have been suggested. Some have been accepted, fully described (even standardized), and are in use. Others have been found insecure, and should never be used. Still others don't categorize as confidentiality, authenticity, or authenticated encryption – for example key feedback mode and Davies–Meyer hashing.


title: Block cipher mode of operation

text: Disk encryption often uses special purpose modes specifically designed for the application. Tweakable narrow-block encryption modes (LRW, XEX, and XTS) and wide-block encryption modes (CMC and EME) are designed to securely encrypt sectors of a disk (see disk encryption theory).


title: Block cipher mode of operation

text: Many modes use an initialization vector (IV) which, depending on the mode, may have requirements such as being only used once (a nonce) or being unpredictable ahead of its publication, etc. Reusing an IV with the same key in CTR, GCM or OFB mode results in XORing the same keystream with two or more plaintexts, a clear misuse of a stream, with a catastrophic loss of security. Deterministic authenticated encryption modes such as the NIST Key Wrap algorithm and the SIV (RFC 5297) AEAD mode do not require an IV as an input, and return the same ciphertext and authentication tag every time for a given plaintext and key. Other IV misuse-resistant modes such as AES-GCM-SIV benefit from an IV input, for example in the maximum amount of data that can be safely encrypted with one key, while not failing catastrophically if the same IV is used multiple times.


title: Block cipher mode of operation

text: Block ciphers can also be used in other cryptographic protocols. They are generally used in modes of operation similar to the block modes described here. As with all protocols, to be cryptographically secure, care must be taken to design these modes of operation correctly.


title: Block cipher mode of operation

text: There are several schemes which use a block cipher to build a cryptographic hash function. See one-way compression function for descriptions of several such methods.


title: Block cipher mode of operation

text: Cryptographically secure pseudorandom number generators (CSPRNGs) can also be built using block ciphers.


title: Block cipher mode of operation

text: Message authentication codes (MACs) are often built from block ciphers. CBC-MAC, OMAC and PMAC are examples.


title: Jet stream

text: Jet streams are fast flowing, narrow, meandering air currents in the atmospheres of some planets, including Earth. On Earth, the main jet streams are located near the altitude of the tropopause and are westerly winds (flowing west to east). Jet streams may start, stop, split into two or more parts, combine into one stream, or flow in various directions including opposite to the direction of the remainder of the jet.


title: Jet stream

text: The strongest jet streams are the polar jets, at above sea level, and the higher altitude and somewhat weaker subtropical jets at . The Northern Hemisphere and the Southern Hemisphere each have a polar jet and a subtropical jet. The northern hemisphere polar jet flows over the middle to northern latitudes of North America, Europe, and Asia and their intervening oceans, while the southern hemisphere polar jet mostly circles Antarctica, both all year round.


title: Jet stream

text: Jet streams are the product of two factors: the atmospheric heating by solar radiation that produces the large-scale polar, Ferrel, and Hadley circulation cells, and the action of the Coriolis force acting on those moving masses. The Coriolis force is caused by the planet's rotation on its axis. On other planets, internal heat rather than solar heating drives their jet streams. The polar jet stream forms near the interface of the polar and Ferrel circulation cells; the subtropical jet forms near the boundary of the Ferrel and Hadley circulation cells.


title: Jet stream

text: Other jet streams also exist. During the Northern Hemisphere summer, easterly jets can form in tropical regions, typically where dry air encounters more humid air at high altitudes. Low-level jets also are typical of various regions such as the central United States. There are also jet streams in the thermosphere.


title: Jet stream

text: Meteorologists use the location of some of the jet streams as an aid in weather forecasting. The main commercial relevance of the jet streams is in air travel, as flight time can be dramatically affected by either flying with the flow or against. Often, airlines work to fly 'with' the jet stream to obtain significant fuel cost and time savings . Dynamic North Atlantic Tracks are one example of how airlines and air traffic control work together to accommodate the jet stream and winds aloft that results in the maximum benefit for airlines and other users. Clear-air turbulence, a potential hazard to aircraft passenger safety, is often found in a jet stream's vicinity, but it does not create a substantial alteration on flight times.


title: Jet stream

text: The first indications of this phenomenon came from American professor Elias Loomis in the 1800s, when he proposed a powerful air current in the upper air blowing west to east across the United States as an explanation for the behaviour of major storms. After the 1883 eruption of the Krakatoa volcano, weather watchers tracked and mapped the effects on the sky over several years. They labelled the phenomenon the "equatorial smoke stream". In the 1920s, a Japanese meteorologist, Wasaburo Oishi, detected the jet stream from a site near Mount Fuji. He tracked pilot balloons, also known as pibals (balloons used to determine upper level winds), as they rose into the atmosphere. Oishi's work largely went unnoticed outside Japan because it was published in Esperanto. American pilot Wiley Post, the first man to fly around the world solo in 1933, is often given some credit for discovery of jet streams. Post invented a pressurized suit that let him fly above . In the year before his death, Post made several attempts at a high-altitude transcontinental flight, and noticed that at times his ground speed greatly exceeded his air speed.


title: Jet stream

text: German meteorologist Heinrich Seilkopf is credited with coining a special term, "Strahlströmung" (literally "jet current"), for the phenomenon in 1939. Many sources credit real understanding of the nature of jet streams to regular and repeated flight-path traversals during World War II. Flyers consistently noticed westerly tailwinds in excess of in flights, for example, from the US to the UK. Similarly in 1944 a team of American meteorologists in Guam, including Reid Bryson, had enough observations to forecast very high west winds that would slow World War II bombers travelling to Japan.


title: Jet stream

text: Polar jet streams are typically located near the 250 hPa (about 1/4 atmosphere) pressure level, or above sea level, while the weaker subtropical jet streams are much higher, between . Jet streams wander laterally dramatically, and changes in their altitude. The jet streams form near breaks in the tropopause, at the transitions between the polar, Ferrel and Hadley circulation cells, and whose circulation, with the Coriolis force acting on those masses, drives the jet streams. The polar jets, at lower altitude, and often intruding into mid-latitudes, strongly affect weather and aviation. The polar jet stream is most commonly found between latitudes 30° and 60° (closer to 60°), while the subtropical jet streams are located close to latitude 30°. These two jets merge at some locations and times, while at other times they are well separated. The northern polar jet stream is said to "follow the sun" as it slowly migrates northward as that hemisphere warms, and southward again as it cools.


title: Jet stream

text: The width of a jet stream is typically a few hundred kilometres or miles and its vertical thickness often less than .


title: Jet stream

text: Jet streams are typically continuous over long distances, but discontinuities are also common. The path of the jet typically has a meandering shape, and these meanders themselves propagate eastward, at lower speeds than that of the actual wind within the flow. Each large meander, or wave, within the jet stream is known as a Rossby wave (planetary wave). Rossby waves are caused by changes in the Coriolis effect with latitude. Shortwave troughs, are smaller scale waves superimposed on the Rossby waves, with a scale of long, that move along through the flow pattern around large scale, or longwave, "ridges" and "troughs" within Rossby waves. Jet streams can split into two when they encounter an upper-level low, that diverts a portion of the jet stream under its base, while the remainder of the jet moves by to its north.


title: Jet stream

text: The wind speeds are greatest where temperature differences between air masses are greatest, and often exceed . Speeds of have been measured.


title: Jet stream

text: The jet stream moves from West to East bringing changes of weather. Meteorologists now understand that the path of jet streams affects cyclonic storm systems at lower levels in the atmosphere, and so knowledge of their course has become an important part of weather forecasting. For example, in 2007 and 2012, Britain experienced severe flooding as a result of the polar jet staying south for the summer.


title: Jet stream

text: In general, winds are strongest immediately under the tropopause (except locally, during tornadoes, tropical cyclones or other anomalous situations). If two air masses of different temperatures or densities meet, the resulting pressure difference caused by the density difference (which ultimately causes wind) is highest within the transition zone. The wind does not flow directly from the hot to the cold area, but is deflected by the Coriolis effect and flows along the boundary of the two air masses.


title: Jet stream

text: All these facts are consequences of the thermal wind relation. The balance of forces acting on an atmospheric air parcel in the vertical direction is primarily between the gravitational force acting on the mass of the parcel and the buoyancy force, or the difference in pressure between the top and bottom surfaces of the parcel. Any imbalance between these forces results in the acceleration of the parcel in the imbalance direction: upward if the buoyant force exceeds the weight, and downward if the weight exceeds the buoyancy force. The balance in the vertical direction is referred to as hydrostatic. Beyond the tropics, the dominant forces act in the horizontal direction, and the primary struggle is between the Coriolis force and the pressure gradient force. Balance between these two forces is referred to as geostrophic. Given both hydrostatic and geostrophic balance, one can derive the thermal wind relation: the vertical gradient of the horizontal wind is proportional to the horizontal temperature gradient. If two air masses, one cold and dense to the North and the other hot and less dense to the South, are separated by a vertical boundary and that boundary should be removed, the difference in densities will result in the cold air mass slipping under the hotter and less dense air mass. The Coriolis effect will then cause poleward-moving mass to deviate to the East, while equatorward-moving mass will deviate toward the west. The general trend in the atmosphere is for temperatures to decrease in the poleward direction. As a result, winds develop an eastward component and that component grows with altitude. Therefore, the strong eastward moving jet streams are in part a simple consequence of the fact that the Equator is warmer than the North and South poles.


title: Jet stream

text: The thermal wind relation does not explain why the winds are organized into tight jets, rather than distributed more broadly over the hemisphere. One factor that contributes to the creation of a concentrated polar jet is the undercutting of sub-tropical air masses by the more dense polar air masses at the polar front. This causes a sharp north-south pressure (south-north potential vorticity) gradient in the horizontal plane, an effect which is most significant during double Rossby wave breaking events. At high altitudes, lack of friction allows air to respond freely to the steep pressure gradient with low pressure at high altitude over the pole. This results in the formation of planetary wind circulations that experience a strong Coriolis deflection and thus can be considered 'quasi-geostrophic'. The polar front jet stream is closely linked to the frontogenesis process in midlatitudes, as the acceleration/deceleration of the air flow induces areas of low/high pressure respectively, which link to the formation of cyclones and anticyclones along the polar front in a relatively narrow region.


title: Jet stream

text: A second factor which contributes to a concentrated jet is more applicable to the subtropical jet which forms at the poleward limit of the tropical Hadley cell, and to first order this circulation is symmetric with respect to longitude. Tropical air rises to the tropopause, and moves poleward before sinking; this is the Hadley cell circulation. As it does so it tends to conserve angular momentum, since friction with the ground is slight. Air masses that begin moving poleward are deflected eastward by the Coriolis force (true for either hemisphere), which for poleward moving air implies an increased westerly component of the winds (note that deflection is leftward in the southern hemisphere).


title: Jet stream

text: Jupiter's atmosphere has multiple jet streams, caused by the convection cells that form the familiar banded color structure; on Jupiter, these convection cells are driven by internal heating. The factors that control the number of jet streams in a planetary atmosphere is an active area of research in dynamical meteorology. In models, as one increases the planetary radius, holding all other parameters fixed, the number of jet streams decreases.


title: Jet stream

text: The subtropical jet stream rounding the base of the mid-oceanic upper trough is thought to be one of the causes most of the Hawaiian Islands have been resistant to the long list of Hawaii hurricanes that have approached. For example, when Hurricane Flossie (2007) approached and dissipated just before reaching landfall, the U.S. National Oceanic and Atmospheric Administration (NOAA) cited vertical wind shear as evidenced in the photo.


title: Jet stream

text: On Earth, the northern polar jet stream is the most important one for aviation and weather forecasting, as it is much stronger and at a much lower altitude than the subtropical jet streams and also covers many countries in the Northern Hemisphere, while the southern polar jet stream mostly circles Antarctica and sometimes the southern tip of South America. Thus, the term "jet stream" in these contexts usually implies the northern polar jet stream.


title: Jet stream

text: The location of the jet stream is extremely important for aviation. Commercial use of the jet stream began on 18 November 1952, when Pan Am flew from Tokyo to Honolulu at an altitude of . It cut the trip time by over one-third, from 18 to 11.5 hours. Not only does it cut time off the flight, it also nets fuel savings for the airline industry. Within North America, the time needed to fly east across the continent can be decreased by about 30 minutes if an airplane can fly with the jet stream, or increased by more than that amount if it must fly west against it.


title: Jet stream

text: Associated with jet streams is a phenomenon known as clear-air turbulence (CAT), caused by vertical and horizontal wind shear caused by jet streams. The CAT is strongest on the cold air side of the jet, next to and just under the axis of the jet. Clear-air turbulence can cause aircraft to plunge and so present a passenger safety hazard that has caused fatal accidents, such as the death of one passenger on United Airlines Flight 826.


title: Jet stream

text: Scientists are investigating ways to harness the wind energy within the jet stream. According to one estimate of the potential wind energy in the jet stream, only one percent would be needed to meet the world's current energy needs. The required technology would reportedly take 10–20 years to develop.


title: Jet stream

text: There are two major but divergent scientific articles about jet stream power. Archer & Caldeira claim that the Earth's jet streams could generate a total power of 1700 terawatts (TW) and that the climatic impact of harnessing this amount would be negligible. However, Miller, Gans, & Kleidon claim that the jet streams could generate a total power of only 7.5 TW and that the climatic impact would be catastrophic.


title: Jet stream

text: Near the end of World War II, from late 1944 until early 1945, the Japanese Fu-Go balloon bomb, a type of fire balloon, was designed as a cheap weapon intended to make use of the jet stream over the Pacific Ocean to reach the west coast of Canada and the United States. Relatively ineffective as weapons, they were used in one of the few attacks on North America during World War II, causing six deaths and a small amount of damage. However, the Japanese were world leaders in biological weapons research at this time. The Japanese Imperial Army's Noborito Institute cultivated anthrax and plague "Yersinia pestis"; furthermore, it produced enough cowpox viruses to infect the entire United States.


title: Jet stream

text: Emperor Hirohito did not permit deployment of biological weapons on the basis of a report by President Staff Officer Umezu on 25 October 1944. Consequently, biological warfare using Fu-Go balloons was not implemented.


title: Jet stream

text: El Niño-Southern Oscillation (ENSO) influences the average location of upper-level jet streams, and leads to cyclical variations in precipitation and temperature across North America, as well as affecting tropical cyclone development across the eastern Pacific and Atlantic basins. Combined with the Pacific Decadal Oscillation, ENSO can also impact cold season rainfall in Europe. Changes in ENSO also change the location of the jet stream over South America, which partially affects precipitation distribution over the continent.


title: Jet stream

text: During El Niño events, increased precipitation is expected in California due to a more southerly, zonal, storm track. During the Niño portion of ENSO, increased precipitation falls along the Gulf coast and Southeast due to a stronger than normal, and more southerly, polar jet stream. Snowfall is greater than average across the southern Rockies and Sierra Nevada mountain range, and is well below normal across the Upper Midwest and Great Lakes states. The northern tier of the lower 48 exhibits above normal temperatures during the fall and winter, while the Gulf coast experiences below normal temperatures during the winter season. The subtropical jet stream across the deep tropics of the Northern Hemisphere is enhanced due to increased convection in the equatorial Pacific, which decreases tropical cyclogenesis within the Atlantic tropics below what is normal, and increases tropical cyclone activity across the eastern Pacific. In the Southern Hemisphere, the subtropical jet stream is displaced equatorward, or north, of its normal position, which diverts frontal systems and thunderstorm complexes from reaching central portions of the continent.


title: Jet stream

text: Across North America during La Niña, increased precipitation is diverted into the Pacific Northwest due to a more northerly storm track and jet stream. The storm track shifts far enough northward to bring wetter than normal conditions (in the form of increased snowfall) to the Midwestern states, as well as hot and dry summers. Snowfall is above normal across the Pacific Northwest and western Great Lakes. Across the North Atlantic, the jet stream is stronger than normal, which directs stronger systems with increased precipitation towards Europe.


title: Jet stream

text: Evidence suggests the jet stream was at least partly responsible for the widespread drought conditions during the 1930s Dust Bowl in the Midwest United States. Normally, the jet stream flows east over the Gulf of Mexico and turns northward pulling up moisture and dumping rain onto the Great Plains. During the Dust Bowl, the jet stream weakened and changed course traveling farther south than normal. This starved the Great Plains and other areas of the Midwest of rainfall, causing extraordinary drought conditions.


title: Jet stream

text: Since the early 2000s, climate models have consistently identified that global warming will gradually push jet streams poleward. In 2008, this was confirmed by observational evidence, which proved that from 1979 to 2001, the northern jet stream moved northward at an average rate of per year, with a similar trend in the Southern Hemisphere jet stream. Climate scientists have hypothesized that the jet stream will also gradually weaken as a result of global warming. Trends such as Arctic sea ice decline, reduced snow cover, evapotranspiration patterns, and other weather anomalies have caused the Arctic to heat up faster than other parts of the globe, in what is known as the Arctic amplification. In 2021-2022, it was found that since 1979, the warming within the Arctic Circle has been nearly four times faster than the global average, and some hotspots in the Barents Sea area warmed up to seven times faster than the global average. While the Arctic remains one of the coldest places on Earth today, the temperature gradient between it and the warmer parts of the globe will continue to diminish with every decade of global warming as the result of this amplification. If this gradient has a strong influence on the jet stream, then it will eventually become weaker and more variable in its course, which would allow more cold air from the polar vortex to leak mid-latitudes and slow the progression of Rossby Waves, leading to more persistent and more extreme weather.


title: Jet stream

text: The hypothesis above is closely associated with Jennifer Francis, who had first proposed it in a 2012 paper co-authored by Stephen J. Vavrus. While some paleoclimate reconstructions have suggested that the polar vortex becomes more variable and causes more unstable weather during periods of warming back in 1997, this was contradicted by climate modelling, with PMIP2 simulations finding in 2010 that the Arctic oscillation was much weaker and more negative during the Last Glacial Maximum, and suggesting that warmer periods have stronger positive phase AO, and thus less frequent leaks of the polar vortex air. However, a 2012 review in the "Journal of the Atmospheric Sciences" noted that "there [has been] a significant change in the vortex mean state over the twenty-first century, resulting in a weaker, more disturbed vortex.", which contradicted the modelling results but fit the Francis-Vavrus hypothesis. Additionally, a 2013 study noted that the then-current CMIP5 tended to strongly underestimate winter blocking trends, and other 2012 research had suggested a connection between declining Arctic sea ice and heavy snowfall during midlatitude winters.


title: Jet stream

text: In 2013, further research from Francis connected reductions in the Arctic sea ice to extreme summer weather in the northern mid-latitudes, while other research from that year identified potential linkages between Arctic sea ice trends and more extreme rainfall in the European summer, At the time, it was also suggested that this connection between Arctic amplification and jet stream patterns was involved in the formation of Hurricane Sandy and played a role in the Early 2014 North American cold wave In 2015, Francis' next study concluded that highly amplified jet-stream patterns are occurring more frequently in the past two decades. Hence, continued heat-trapping emissions favour increased formation of extreme events caused by prolonged weather conditions.


title: Jet stream

text: Studies published in 2017 and 2018 identified stalling patterns of Rossby waves in the northern hemisphere jet stream as the culprit behind other almost stationary extreme weather events, such as the 2018 European heatwave, the 2003 European heat wave, 2010 Russian heat wave or the 2010 Pakistan floods, and suggested that these patterns were all connected to Arctic amplification. Further work from Francis and Vavrus that year suggested that amplified Arctic warming is observed as stronger in lower atmospheric areas because the expanding process of warmer air increases pressure levels which decreases poleward geopotential height gradients. As these gradients are the reason that cause west to east winds through the thermal wind relationship, declining speeds are usually found south of the areas with geopotential increases. In 2017, Francis explained her findings to the "Scientific American": "A lot more water vapor is being transported northward by big swings in the jet stream. That's important because water vapor is a greenhouse gas just like carbon dioxide and methane. It traps heat in the atmosphere. That vapor also condenses as droplets we know as clouds, which themselves trap more heat. The vapor is a big part of the amplification story—a big reason the Arctic is warming faster than anywhere else."


title: Jet stream

text: In a 2017 study conducted by climatologist Dr. Judah Cohen and several of his research associates, Cohen wrote that "[the] shift in polar vortex states can account for "most" of the recent winter cooling trends over Eurasian midlatitudes". A 2018 paper from Vavrus and others linked Arctic amplification to more persistent hot-dry extremes during the midlatitude summers, as well as the midlatitude winter continental cooling. Another 2017 paper estimated that when the Arctic experiences anomalous warming, primary production in the North America goes down by between 1% and 4% on average, with some states suffering up to 20% losses. A 2021 study found that a stratospheric polar vortex disruption is linked with extreme cold winter weather across parts of Asia and North America, including the February 2021 North American cold wave. Another 2021 study identified a connection between the Arctic sea ice loss and the increased size of wildfires in the Western United States.


title: Jet stream

text: However, because the specific observations are considered short-term observations, there is considerable uncertainty in the conclusions. Climatology observations require several decades to definitively distinguish various forms of natural variability from climate trends. This point was stressed by reviews in 2013 and in 2017. A study in 2014 concluded that Arctic amplification significantly decreased cold-season temperature variability over the Northern Hemisphere in recent decades. Cold Arctic air intrudes into the warmer lower latitudes more rapidly today during autumn and winter, a trend projected to continue in the future except during summer, thus calling into question whether winters will bring more cold extremes. A 2019 analysis of a data set collected from 35 182 weather stations worldwide, including 9116 whose records go beyond 50 years, found a sharp decrease in northern midlatitude cold waves since the 1980s.


title: Jet stream

text: Moreover, a range of long-term observational data collected during 2010s and published in 2020s now suggests that the intensification of Arctic amplification since the early 2010s was not linked to significant changes on midlatitude atmospheric patterns. State-of-the-art modelling research of PAMIP (Polar Amplification Model Intercomparison Project) improved upon the 2010 findings of PMIP2 - it did find that sea ice decline would weaken the jet stream and increase the probability of atmospheric blocking, but the connection was very minor, and typically insignificant next to interannual variability. In 2022, a follow-up study found that while the PAMIP average had likely underestimated the weakening caused by sea ice decline by 1.2 to 3 times, even the corrected connection still amounts to only 10% of the jet stream's natural variability.


title: Jet stream

text: Additionally, a 2021 study found that while jet streams had indeed slowly moved polewards since 1960 as was predicted by models, they did not weaken, in spite of a small increase in waviness. A 2022 re-analysis of the aircraft observational data collected over 2002–2020 suggested that the North Atlantic jet stream had actually strengthened. Finally, a 2021 study was able to reconstruct jet stream patterns over the past 1,250 years based on Greenland ice cores, and found that all of the recently observed changes remain within range of natural variability: the earliest likely time of divergence is in 2060, under the Representative Concentration Pathway 8.5 which implies continually accelerating greenhouse gas emissions.


title: Jet stream

text: The polar-night jet stream forms mainly during the winter months when the nights are much longer, hence polar nights, in their respective hemispheres at around 60° latitude. The polar night jet moves at a greater height (about ) than it does during the summer. During these dark months the air high over the poles becomes much colder than the air over the Equator. This difference in temperature gives rise to extreme air pressure differences in the stratosphere, which, when combined with the Coriolis effect, create the polar night jets, that race eastward at an altitude of about . The polar vortex is circled by the polar night jet. The warmer air can only move along the edge of the polar vortex, but not enter it. Within the vortex, the cold polar air becomes increasingly cold with neither warmer air from lower latitudes nor energy from the Sun entering during the polar night.


title: Jet stream

text: A barrier jet in the low levels forms just upstream of mountain chains, with the mountains forcing the jet to be oriented parallel to the mountains. The mountain barrier increases the strength of the low level wind by 45 percent. In the North American Great Plains a southerly low-level jet helps fuel overnight thunderstorm activity during the warm season, normally in the form of mesoscale convective systems which form during the overnight hours. A similar phenomenon develops across Australia, which pulls moisture poleward from the Coral Sea towards cut-off lows which form mainly across southwestern portions of the continent.


title: Jet stream

text: Coastal low-level jets are related to a sharp contrast between high temperatures over land and lower temperatures over the sea and play an important role in coastal weather, giving rise to strong coast parallel winds. Most coastal jets are associated with the oceanic high-pressure systems and thermal low over land. These jets are mainly located along cold eastern boundary marine currents, in upwelling regions offshore California, Peru-Chile, Benguela, Portugal, Canary and West Australia, and offshore Yemen—Oman.


title: Jet stream

text: A valley exit jet is a strong, down-valley, elevated air current that emerges above the intersection of the valley and its adjacent plain. These winds frequently reach speeds of up to at heights of above the ground. Surface winds below the jet tend to be substantially weaker, even when they are strong enough to sway vegetation.


title: Jet stream

text: Valley exit jets are likely to be found in valley regions that exhibit diurnal mountain wind systems, such as those of the dry mountain ranges of the US. Deep valleys that terminate abruptly at a plain are more impacted by these factors than are those that gradually become shallower as downvalley distance increases.


title: Jet stream

text: The mid-level African easterly jet occurs during the Northern Hemisphere summer between 10°N and 20°N above West Africa, and the nocturnal poleward low-level jet occurs in the Great Plains of east and South Africa. The low-level easterly African jet stream is considered to play a crucial role in the southwest monsoon of Africa, and helps form the tropical waves which move across the tropical Atlantic and eastern Pacific oceans during the warm season. The formation of the thermal low over northern Africa leads to a low-level westerly jet stream from June into October.


title: Poinsettia

text: The poinsettia ( or ) ("Euphorbia pulcherrima") is a commercially important flowering plant species of the diverse spurge family Euphorbiaceae. Indigenous to Mexico and Central America, the poinsettia was first described by Europeans in 1834. It is particularly well known for its red and green foliage and is widely used in Christmas floral displays. It derives its common English name from Joel Roberts Poinsett, the first United States Minister to Mexico, who is credited with introducing the plant to the US in the 1820s. Poinsettias are shrubs or small trees, with heights of . Though often stated to be highly toxic, the poinsettia is not dangerous to pets or children. Exposure to the plant, even consumption, most often results in no effect, though it can cause nausea, vomiting, or diarrhea.


title: Poinsettia

text: Wild poinsettias occur from Mexico to southern Guatemala, growing on mid-elevation, Pacific-facing slopes. One population in the Mexican state of Guerrero is much further inland, however, and is thought to be the ancestor of most cultivated populations. Wild poinsettia populations are highly fragmented, as their habitat is experiencing largely unregulated deforestation. They were cultivated by the Aztecs for use in traditional medicine. They became associated with the Christmas holiday and are popular seasonal decorations. Every year in the US, approximately 70 million poinsettias of many cultivated varieties are sold in a six-week period. Many of these poinsettias are grown by Paul Ecke Ranch, which serves half the worldwide market and 70% of the US market.


title: Poinsettia

text: The poinsettia was described as a new species in 1834 by German scientist Johann Friedrich Klotzsch. Klotzsch credited Carl Ludwig Willdenow with the species name ""pulcherrima"", and the authority is given as Willd. ex Klotzsch. The holotype had been collected in Mexico during an 1803–1804 expedition by Alexander von Humboldt and Aimé Bonpland.


title: Poinsettia

text: It was known by the common name "poinsettia" as early as 1836, derived from Joel Roberts Poinsett, a botanist and the first US Minister to Mexico. Possibly as early as 1826, Poinsett began sending poinsettias from Mexico back to his greenhouses in South Carolina. Prior to poinsettia, it was known as "Mexican flame flower" or "painted leaf".


title: Poinsettia

text: "Euphorbia pulcherrima" is a shrub or small tree, typically reaching a height of . The plant bears dark green dentate leaves that measure in length. The colored bracts—which are normally flaming red, with cultivars being orange, pale green, cream, pink, white, or marbled—are often mistaken for flower petals because of their groupings and colors, but are actually leaves. The colors of the bracts are created through photoperiodism, meaning that they require darkness (at least fourteen hours at a time for 6–8 weeks in a row) to change color. The plants also require abundant light during the day for the brightest color.


title: Poinsettia

text: The flowers of the poinsettia are unassuming. They are grouped within the cyathia (small yellow structures found in the center of each leaf bunch, or false flowers). Nothing is known about pollination in wild poinsettias, though wasps are noted to occasionally visit the cyathia. All flowers in the Euphorbiaceae are unisexual (either male or female only), and they are often very small in size. In "Euphorbia", the flowers are reduced even more and then aggregated into an inflorescence or cluster of flowers.


title: Poinsettia

text: Pulcherrol and pulcherryl acetate are among the components of latex. Triterpenes are found in aerial part of this plant including latex and leaves. One of the triterpenoid skeleton is investigated as foundation to drugs for Alzheimer's disease.


title: Poinsettia

text: Poinsettias are popularly, though incorrectly, said to be toxic to humans and other animals. This misconception was spread by a 1919 urban legend of a two-year-old child dying after consuming a poinsettia leaf. In 1944, the plant was included in H. R. Arnold's book "Poisonous Plants of Hawaii" on this premise. Though Arnold later admitted that the story was hearsay and that poinsettias were not proven to be poisonous, the plant was thus thought deadly. In 1970 the US Food and Drug Administration published a newsletter stating erroneously that "one poinsettia leaf can kill a child", and in 1980 they were prohibited from nursing homes in a county in North Carolina due to this supposed toxicity.


title: Poinsettia

text: An attempt to determine a poisonous dose of poinsettia to rats failed, even after reaching experimental doses equivalent to consuming 500 leaves, or nearly of sap. Contact with any part of the plant by children or pets often has no effect, though it may cause nausea, diarrhea, or vomiting if swallowed. External exposure to the plant may result in a skin rash for some. A survey of more than 20,000 calls to the American Association of Poison Control Centers from 1985–1992 related to poinsettia exposure showed no fatalities. In 92.4% of calls, there was no effect from exposure, and in 3.4% of calls there were minor effects, defined as "minimally bothersome". Similarly, a cat or dog's exposure to poinsettias rarely necessitates medical treatment. If ingested, mild drooling or vomiting can occur, or rarely, diarrhea. In rare cases, exposure to the eye may result in eye irritation. Skin exposure to the sap may cause itchiness, redness, or swelling. It can induce asthma and allergic rhinitis in certain groups of people.


title: Poinsettia

text: The poinsettia occurs in North and Central America, from Mexico to southern Guatemala. Its range is about long, encompassing mid-elevation tropical dry forests. Most wild populations are on Pacific-facing slopes in steep canyons. Populations were once found in rolling hill areas, though many have gone extinct. It has been hypothesized that the inaccessibility of the canyons may protect the wild populations from human disturbance. There is a somewhat anomalous population of wild poinsettias in the northern part of the Mexican state of Guerrero and Oaxaca, which is much further inland in the hot and seasonally dry forests than the rest of the species' range. Genetic analyses showed that the wild populations in northern Guerrero are the likely ancestors of most cultivated poinsettias.


title: Poinsettia

text: The tropical dry forests where wild poinsettias grow experience largely unregulated deforestation, resulting in habitat loss. Its natural habitat is thus highly fragmented, particularly near metropolitan areas such as Taxco. Population sizes are frequently very small, with as few as a dozen individuals. Populations can be up to several hundred individuals, but this is not typical. A conservation risk typical for species with wild and cultivated populations is the contamination of the wild gene pool by hybridization with cultivated individuals. This has not been documented in wild poinsettias, though, as cultivars seldom flower and do not produce fruits. As of 2012, wild poinsettias are not protected by Mexican law.


title: Poinsettia

text: Aztec people use the plant to produce red dye and as an antipyretic medication. In Nahuatl, the language of the Aztecs, the plant is called "Cuetlaxochitl", meaning "flower that grows in residues or soil". Today it is known in Mexico and Guatemala as "flor de Nochebuena" or simply "nochebuena", meaning 'Christmas Eve flower'. In Spain it is known as "Flor de Pascua" or "Pascua", meaning Easter flower. In Chile and Peru, the plant became known as the crown of the Andes.


title: Poinsettia

text: The plant's association with Christmas began in 16th-century Mexico, where legend tells of a girl, commonly called Pepita or María, who was too poor to provide a gift for the celebration of Jesus' birthday and was inspired by an angel to gather weeds from the roadside and place them in front of the church altar. Crimson blossoms sprouted from the weeds and became poinsettias. From the 17th century, Franciscan friars in Mexico included the plants in their Christmas celebrations. The star-shaped leaf pattern is said to symbolize the Star of Bethlehem, and the red color represents the blood sacrifice of Jesus's crucifixion.


title: Poinsettia

text: Poinsettias are popular Christmas decorations in homes, churches, offices, and elsewhere across North America, as a result of an extensive marketing campaign by the Ecke family that began by shipping free poinsettias to television stations for use on-air. In the US, December 12 is National Poinsettia Day, marking the anniversary of Joel Roberts Poinsett's death.


title: Poinsettia

text: The Aztecs were the first to cultivate poinsettias. Cultivation in the US began when diplomat Joel Roberts Poinsett sent some of the plants back to his greenhouses in South Carolina in the 1820s. Specific details about its spread from there are largely unverifiable, but it was exhibited at the Pennsylvania Horticultural Society's 1829 Philadelphia Flower Show by Colonel Robert Carr. Carr described it as "a new "Euphorbia" with bright scarlet bracts or floral leaves, presented to the Bartram Collection by Mr. Poinsett, United States Minister of Mexico."


title: Poinsettia

text: The poinsettia is the world's most economically important potted plant. Each year in the US, approximately 70 million poinsettias are sold in a period of six weeks, at a value of US$250 million. In Puerto Rico, where poinsettias are grown extensively in greenhouses, the industry is valued at $5 million annually. There are over 100 cultivated varieties of poinsettia that have been patented in the US.


title: Poinsettia

text: To produce extra axillary buds that are necessary for plants containing multiple flowers, a phytoplasma infection—whose symptoms include the proliferation of axillary buds—is used. The discovery of the role phytoplasmas play in the growth of axillary buds is credited to Ing-Ming Lee of the USDA Agricultural Research Service.


title: Poinsettia

text: Albert Ecke emigrated from Germany to Los Angeles in 1900, opening a dairy and orchard in the Eagle Rock area. He became intrigued by the plant and sold them from street stands. His son, Paul Ecke, developed the grafting technique, but it was the third generation of Eckes, Paul Ecke Jr., who was responsible for advancing the association between the plant and Christmas.


title: Poinsettia

text: Besides changing the market from mature plants shipped by rail to cuttings sent by air, he sent free plants to television stations for them to display on air from Thanksgiving to Christmas. He also appeared on television programs like "The Tonight Show" and Bob Hope's Christmas specials to promote the plants.


title: Poinsettia

text: Until the 1990s, the Ecke family, who had moved their operation to Encinitas, California, in 1923, had a virtual monopoly on poinsettias owing to a technique that made their plants much more attractive. They produced a fuller, more compact plant by grafting two varieties of poinsettia together. A poinsettia left to grow on its own will naturally take an open, somewhat weedy look. The Eckes' technique made it possible to get every seedling to branch, resulting in a bushier plant.


title: Poinsettia

text: In the late 1980s, university researcher John Dole discovered the method previously known only to the Eckes and published it, allowing competitors to flourish, particularly those using low-cost labor in Latin America. The Ecke family's business, now led by Paul Ecke III, decided to stop producing plants in the US, but as of 2008, they still served about 70 percent of the domestic market and 50 percent of the worldwide market.


title: Poinsettia

text: Poinsettias are susceptible to several diseases, mostly fungal, but also bacterial and parasitic. Conditions that promote poinsettia propagation also favor certain diseases. Fungal diseases affecting greenhouse poinsettia operations include "Pythium" root rot, "Rhizoctonia" root and stem rot, black root rot, scab, powdery mildew, and "Botrytis" blight. Bacterial diseases include bacterial soft rot and bacterial canker, while a viral disease is "Poinsettia mosaic virus". Infection by poinsettia branch-inducing phytoplasma is actually desirable, as it keeps the plants shorter with more flowers. It is the first known phytoplasma that has economically advantageous effects.


title: Rena Sofer

text: Rena Sherel Sofer (born December 2, 1968) is an American actress, known for her appearances in daytime television, episodic guest appearances, and made-for-television movies. In 1995, Sofer received a Daytime Emmy Award for her portrayal of Lois Cerullo in the soap opera "General Hospital". From 2013 to 2022, she played the role of Quinn Fuller on the CBS soap opera "The Bold and the Beautiful".


title: Rena Sofer

text: Sofer was born in Arcadia, California, the daughter of Susan Sofer (née Franzblau), a psychology professor, and Martin Sofer, an Orthodox rabbi.


title: Rena Sofer

text: She moved with her father and brother David to Teaneck, New Jersey, in 1970. However, when Sofer was 5 years old, they resided in Western Pennsylvania. They lived in Ambridge, Pennsylvania, where her father led Beth Samuels Jewish Center.


title: Rena Sofer

text: She later attended the Frisch School, a coeducational Modern Orthodox Jewish high school in Paramus, New Jersey. Sofer lived in North Bergen, New Jersey, where her father was rabbi of synagogue Temple Beth El. She graduated from North Bergen High School, then attended classes at Montclair State College.


title: Rena Sofer

text: Sofer first played Lois Marie Cerullo on "General Hospital". Her first appearance was in 1993 as a band manager. However, her first high-profile role was as Rocky McKenzie on the daytime soap opera "Loving" (1988–91).


title: Rena Sofer

text: Sofer is perhaps best known for her role as Lois Cerullo on "General Hospital" (December 15, 1993 – September 24, 1996). She later returned as a guest star (February 7–17, 1997; September 30 – October 2, 1997). Her portrayal of the outrageous Lois won Sofer a Daytime Emmy Award in 1995 for Outstanding Supporting Actress in a Drama Series.


title: Rena Sofer

text: In May 2013, it was announced that Sofer would join the CBS soap opera "The Bold and the Beautiful", in a newly created role of Quinn Fuller; her first episode aired on July 12. After nine years on the canvas, Sofer opted to end her run in the role of Quinn; she last aired onscreen on August 29, 2022.


title: Rena Sofer

text: Sofer has appeared in several high-profile prime time television series in a guest star/supporting cast member roles: "Seinfeld", "Melrose Place", "The Chronicle", "Ed", "Friends", "Spin City", "Blind Justice", "Ghost Whisperer", "24", "NCIS", and "Two and a Half Men".


title: Rena Sofer

text: Sofer briefly joined the cast of the NBC sitcom "Just Shoot Me!", playing the character Vicky Costa. The network later cast Sofer in the short-lived US remake of the UK series "Coupling".


title: Rena Sofer

text: In recent years, Rena Sofer has appeared in the NBC TV series "Heroes" as the recurring character Heidi Petrelli, wife of aspiring politician Nathan Petrelli (Adrian Pasdar). She appeared on "Two and a Half Men" in 2008, as a former girlfriend of the character Charlie Harper (Charlie Sheen). Rena also has guest starred on "Dirty Sexy Money" playing an intrepid reporter and played a ghost on "Ghost Whisperer". In early 2010, Sofer began a recurring role on "NCIS" as Attorney Margaret Allison Hart, a potential love interest for the character Leroy Jethro Gibbs (Mark Harmon). She had a brief guest role on "Bones" as a love interest for the character Seeley Booth (David Boreanaz).


title: Rena Sofer

text: In film, she appeared as a love interest of Ben Stiller's character in the film "Keeping the Faith", starring Jenna Elfman, Stiller and Edward Norton (who also directed). She also played a bride to-be with Melanie Griffith in Sidney Lumet's movie "A Stranger Among Us" and in Penelope Buitenhuis's movie "The Secret of Hidden Lake".


title: Rena Sofer

text: She played the P.E. teacher Ms. Desjarden in the television film adaptation of "Carrie" in 2002. She starred in the television movie "Always and Forever" which aired October 24, 2009 on the Hallmark Channel. She has been doing TV movies since 1992, when she starred as Andrea Larson in the television movie "".


title: Rena Sofer

text: Sofer and her "General Hospital" co-star Wally Kurth, who played her onscreen love interest, became involved as their characters' storyline progressed. In 1995, the actors were married and had a daughter, Rosabel Rosalind Kurth. In 1997, Sofer and Kurth divorced.


title: Rena Sofer

text: Sofer married television director and producer Sanford Bookstaver in 2003. On August 5, 2005, Sofer gave birth to her second daughter, her first with Bookstaver, in Los Angeles. Sofer and Bookstaver eventually divorced in 2017. In 2019, Sofer announced they had reconciled and in April announced their engagement, and they later remarried in 2019


title: Hipster (contemporary subculture)

text: The 21st-century hipster is a subculture (sometimes called hipsterism). Fashion is one of the major markers of hipster identity. Members of the subculture typically do not self-identify as hipsters, and the word "hipster" is often used as a pejorative for someone who is pretentious or overly concerned with appearing trendy.


title: Hipster (contemporary subculture)

text: Stereotypical fashion elements include vintage clothes, alternative fashion, or a mixture of different fashions, often including skinny jeans, checked shirts, knit beanies, a full beard or deliberately attention-grabbing moustache, and thick-rimmed or lensless glasses. The subculture is often associated with indie and alternative music. In the United States, it is mostly associated with perceived upper-middle-class white young adults who gentrify urban areas. The subculture has been critiqued as lacking authenticity, promoting conformity and embodying a particular ethic of consumption that seeks to commodify the idea of rebellion or counterculture.


title: Hipster (contemporary subculture)

text: The term "hipster" in its present usage first appeared in the 1990s and became widely used in the late 2000s and early 2010s, being derived from the earlier hipster movements of the 1940s.


title: Hipster (contemporary subculture)

text: In early 2000, both "The New York Times" and "Time Out New York" ("TONY") ran profiles of Williamsburg, Brooklyn, referring to "bohemians" and "arty East Village types," respectively. By 2003, when "The Hipster Handbook" was published by Williamsburg resident Robert Lanham, the term "hipster" (originally referring to the 1940s subculture) had come into widespread use in relation to Williamsburg and similar neighborhoods. "The Hipster Handbook" described hipsters as young people with "mop-top haircuts, swinging retro pocketbooks, talking on cell phones, smoking European cigarettes... strutting in platform shoes with a biography of Che Guevara sticking out of their bags." Lanham further describes hipsters: "You graduated from a liberal arts school whose football team hasn't won a game since the Reagan administration[,]" and "you have one Republican friend who you always describe as being your 'one Republican friend. Mark Greif dates the initial phase of the revival of the term "hipster" to refer to this subculture from 1999 to 2003. While hipsters usually come from affluent white families, they can come from a multitude of backgrounds. A running theme of hipsters is having parents who are supporters of former President Ronald Reagan.A similar phenomenon occurred in the United Kingdom, with young, comparatively affluent workers in the media and digital industries moving into traditionally working class areas of London such as Hoxton, Spitalfields, and, particularly, Shoreditch with the subsequent gentrification of these areas. The subculture was parodied in the magazine "Shoreditch Twat" (1999) and the television sitcom "Nathan Barley" (2005). The series, about a self-described "self-facilitating media node," led to the term "Nathan Barleys" being used pejoratively in London for the subculture it parodied.


title: Hipster (contemporary subculture)

text: In 2008, "Utne Reader" magazine writer Jake Mohan described "hipster rap" as "consisting of the most recent crop of MCs and DJs who flout conventional hip-hop fashions, eschewing baggy clothes and gold chains for tight jeans, big sunglasses, the occasional keffiyeh, and other trappings of the hipster lifestyle." He notes that the "old-school hip-hop website Unkut, and Jersey City rapper Mazzi" have criticized mainstream rappers whom they deem to be posers "for copping the metrosexual appearances of hipster fashion." "Prefix Mag" writer Ethan Stanislawski argues that there are racial elements to the rise of hipster rap. He claims that there "have been a slew of angry retorts to the rise of hipster rap," which he says can be summed up as "white kids want the funky otherness of hip-hop...without all the scary black people."


title: Hipster (contemporary subculture)

text: A 2009 "Time" magazine article described hipsters as follows: "take your grandmother's sweater and Bob Dylan's Wayfarers, add jean shorts, Converse All-Stars and a can of Pabst and bam — hipster."


title: Hipster (contemporary subculture)

text: "Slate" writer Brandon Stosuy noted that "Heavy metal has recently conquered a new frontier, making an unexpected crossover into the realm of hipsterdom." He argues that the "current revival seems to be a natural mutation from the hipster fascination with post-punk, noise, and no wave," which allowed even the "nerdiest indie kids to dip their toes into jagged, autistic sounds." He argues that a "byproduct" of this development was an "investigation of a musical culture that many had previously feared or fetishized from afar."


title: Hipster (contemporary subculture)

text: Fixed-gear bicycles are associated with the hipster subculture. "Slate" calls the bikes an "increasingly common hipster accessory." An association of hipsters with an increasing popularity of full beards dates from before 2010. In 2016, historian Alun Withey remarked that "The hipster beard, or lumberjack beard, is going to be the defining facial hair of this generation." Other hipster trends in the 2010s have included knitting, photography, horticulture, urban beekeeping, specialty coffee, craft beer, taxidermy, fedoras, and printing and bookbinding classes.


title: Hipster (contemporary subculture)

text: In 2017, the British logistics and marketing firm "MoveHub" published a "Hipster Index" for the United States. This first study drew from five data points: microbreweries, thrift stores, vegan restaurants and tattoo parlors, and they compounded this data with cities' rent inflation in the previous year. In the following year, "MoveHub" came out with a similar study, this time measuring the most Hipster cities in the world. The metrics were slightly different for this study: they measured vegan eateries, coffee shops, tattoo studios, vintage boutiques, and record stores. For the global study, they also limited their search to larger cities, with populations above 150,000 residents. For this reason, many American cities which ranked highly on the U.S. study in 2017 were not eligible for the 2018 study. iHeartRadio, a media and entertainment company, then took "MoveHub"'s 2018 study, and narrowed it down to the Canadian cities. All three of these tables are referenced in the following sections about regions which have large hipster cultures. Top of the world list is the city of Brighton in the UK, whose MP Caroline Lucas was the sole Green Party MP voted into the British Parliament in the 2010, 2015 and 2017 general elections.


title: Hipster (contemporary subculture)

text: In the above global index put out by "MoveHub," three of the ten most hipster-centric cities around the world were listed as being in either Oregon or Washington state: Portland, Seattle, and Spokane. Of the top 20 hipster cities in the U.S., six of them were in the Pacific Northwest. This includes, in order: Vancouver, Washington; Boise, Idaho; Tacoma, Washington; Spokane, Washington; Portland, Oregon; and Seattle, Washington.


title: Hipster (contemporary subculture)

text: While Canada as a whole is often known for their liberal philosophy and openness towards alternative living, some of the listed hipster cities in Canada are in the Canadian province of British Columbia, which is just north of Washington state, and this included three of the five top-ranking cities—Victoria, Kelowna, and Vancouver.


title: Hipster (contemporary subculture)

text: Young adults (Millennials) are increasingly influencing culture in a number of cities throughout the Southwest and Rocky Mountain region. These cities are gaining a distinctive artsy, alternative atmosphere which is strongly associated with the term "hipster", forming havens for alternative, liberal lifestyles and politics in the midst of regions which normally have a strong association with the GOP and very traditional, conservative values.


title: Hipster (contemporary subculture)

text: One of these cities is Austin, Texas, well known as the home of the South by Southwest Music Festival. Texas is well known for its loyalty to the Republican party, but Austin is one of the few locales in Texas that reliably vote Democratic. There are also several organic foods and cosmetics companies based out of the city. The neighborhood of East Austin is an especially popular neighborhood for hipster-types to live in.


title: Hipster (contemporary subculture)

text: Another example of a liberal enclave in a conservative state is Salt Lake City, Utah. In the 2016 Presidential Election, a majority of voters chose Democrat Hillary Clinton in only two Utah counties, both located right around Salt Lake City. On the aforementioned "MoveHub" list of the 20 most hipster cities in America, Salt Lake City placed No. 2 in the whole nation. In a state known for its Mormon faith, Salt Lake City has become a favorite residence of LGBT people, and has sprouted an impressive host of microbreweries. The city also has many vegan stores and hiking trails.


title: Hipster (contemporary subculture)

text: Denver is another often-cited example of a famous pilgrimage destination for Millennials. Denver has a burgeoning reputation for its microbreweries. The city is also well known as a hiking and skiing destination. The city reportedly has one of the most active and "fit" populations in the U.S. The city is one of the 10 most dog-friendly cities in America, and has the highest number per-capita of dog walkers and pet sitters. In the music industry, one of the most famous venues for concerts, and one which many bands profess as being their favorite to perform at, is Red Rocks Amphitheatre. Bands sometimes have to book popular dates as far as five years in advance.


title: Hipster (contemporary subculture)

text: Other locales in the Southwest region which made MoveHub's list of the 20 Most Hipster Cities include Tucson, Arizona; Santa Rosa, California; Reno, Nevada; and Albuquerque, New Mexico.


title: Hipster (contemporary subculture)

text: As hipsters—"young creatives" priced out of Bohemian urban neighborhoods in Brooklyn such as Williamsburg, Park Slope, and Greenpoint—moved into suburbs near New York City, "The New York Times" coined the neologism "Hipsturbia" to describe the hip lifestyle as lived in suburbia. Hastings-on-Hudson, Dobbs Ferry, Irvington, and Tarrytown, all in nearby Westchester County, were cited.


title: Hipster (contemporary subculture)

text: A minor trend of cross acculturation of Chabad Hasidism and Hipster subculture appeared within the New York Jewish community, beginning in the late 2000s. A significant number of members of the Chabad Hasidic community, mostly residing Crown Heights, Brooklyn, appear to now have adopted various cultural affinities as the local hipster subculture. These cross-acculturated Hasidim have been dubbed "Chabad hipsters" or "Hasidic hipsters." The Soho Synagogue, established by Chabad emissaries in SoHo, Manhattan, have branded themselves as a "hipster synagogue." The trend of Chabad Hasidic hipsters stands in contrast to the tensions experienced between the Satmar Hasidic community in Williamsburg and local hipsters.


title: Hipster (contemporary subculture)

text: The 2014 song "Brooklyn Baby" by Lana Del Rey is notable for containing satirical elements targeting the New York hipster subculture: its chorus highlights "a stable of cliches about hipsters, Brooklyn, millennials and other things Del Rey herself is known to idolize." These elements include: having a boyfriend in a band, drug use (of amphetamines and hydroponic marijuana), obsession with Lou Reed and Beat Generation poetry, wearing feathers in hair, collecting jazz records, playing different musical instruments, and self-proclaiming coolness.


title: Hipster (contemporary subculture)

text: There has been a parallel movement within the American Muslim community with members termed "mipsters."


title: Hipster (contemporary subculture)

text: The Soviet equivalent of the hipster or beatnik, known as stilyagi, first appeared during the mid 1950s and identified with the modern jazz scene. Their outfits were exaggerated caricatures of the costumes worn by western actors and musicians and typically incorporated bright colors, slim-fit pants, thick-soled shoes, vintage clothing from the 1920s and earlier, brightly colored socks, and plaid sportcoats. Following the release of a cult film in 2008, modern hipsters in Moscow and Saint Petersburg revived some aspects of this subculture.


title: Hipster (contemporary subculture)

text: Hipster racism is engaging in behaviors typically regarded as racist and defending them as being performed ironically or satirically. Rachel Dubrofsky and Megan W. Wood have described it as being supposedly "too hip and self-aware to actually mean the racist stuff one expresses." This might include wearing blackface and other performances of stereotyped African Americans, use of the word "nigger", and appropriating cultural dress. Talia Meer argues that hipster racism is rooted in what she calls "hipster exceptionalism," meaning "the idea that something ordinarily offensive or prejudiced is miraculously transformed into something clever, funny and socially relevant, by the assertion that said ordinarily offensive thing is ironic or satirical." As Leslie A. Hahner and Scott J. Varda described it, "those participating in acts of hipster racism understand those acts as racist when practiced by others, but rationalize their own racist performances through a presumed exceptionalism."


title: Hipster (contemporary subculture)

text: Nipsters are a right-wing neo-Nazi hipster movement that emerged in 2014. Nipsters have found ways to bypass the inhibition against right-wing extremist recruitment of adolescents in Germany through their indistinguishable similarity to and affiliation with the Hipster subculture. The media uses the term Nipster (a portmanteau of Nazi and Hipster) for people who combine Hipster style with right-wing and neo-Nazi extremism.


title: Hipster (contemporary subculture)

text: British neo-Nazi terrorist organisation National Action was said to have been a "mixture of hipsters and skinheads." "The National", a Scottish newspaper, described the group as consisting of mostly middle-class hipster neo-fascists.


title: Hipster (contemporary subculture)

text: Hipster sexism, also known as everyday sexism, or ironic sexism, is defined by Alissa Quart in "New York" magazine's fashion blog "The Cut" as "the objectification of women but in a manner that uses mockery, quotation marks, and paradox." It is a form of self-aware sexism that is deemed acceptable given that its perpetrators are conscious of the inherent sexism and objectification of women in whatever action or statement is being carried out by them. It is rooted in the idea that sexism is an outdated and archaic institution which people do not engage in anymore, thereby making the demonstration of sexism seem satirical and ironic.


title: Hipster (contemporary subculture)

text: Hipster sexism may be presented with derision and expressed as harmless. Quart posits that hipster sexism "is a distancing gesture, a belief that simply by applying quotations, uncool, questionable, and even offensive material about women can be alchemically transformed." She notes this form of sexism as having a particular public admissibility, saying that it perpetuates sexism in general due to a public tolerance based upon reasoning that instances of hipster sexism are humorous. Distinguishing socially critiquing comedy from hipster sexism, feminist discourse discusses hipster sexism as humor which, rather than offering critique, employs an evasive methodology which maintains stereotypes and prejudice. Psychology professor Octavia Calder-Dawe suggests that due to this, the practice of hipster sexism also unconsciously influences the idea that sexism should not be spoken of. Hipster sexism relates to postfeminism in that it downplays sexism at large by casually normalizing it on the basis that sexism has been eradicated and thus is not appropriate for serious consideration or discussion.


title: Hipster (contemporary subculture)

text: A tenet of hipster sexism is the casual use of derogatory words such as "bitch" and "slut," on the basis that such use is intended as ironic. Jessica Wakeman, a contributor to "The Frisky", suggests that the label "hipster sexism" enables casual sexism as a means of being ironic, and thus being seen as an acceptable form of sexism.


title: Hipster (contemporary subculture)

text: Quart coined the term "hipster sexism" in 2012, partly as a comment on "hipster racism," a term coined by Carmen Van Kerckhove circa 2007 which had been popularized earlier in 2012. She differentiated it from "classic sexism," which she describes as being "un-ironic, explicit, violent [and] banal."


title: Hipster (contemporary subculture)

text: A 2016 literature review in the "European Journal of Cultural Studies" summarised the hipster culture "as a translocal and layered phenomenon with contextually specific claims to authenticity". While noting that the identity markers realised by hipsters are often localised, it states that Christian Lorentzen of "Time Out New York" argues that "hipsterism fetishizes the authentic" elements of all of the "fringe movements of the postwar era—Beat, hippie, punk, even grunge," and draws on the "cultural stores of every unmelted ethnicity" and "gay style," and then "regurgitates it with a winking inauthenticity." He claims that this group of "18-to-34-year-olds," who are mostly white, "have defanged, skinned and consumed" all of these influences. Lorentzen says hipsters, "in their present undead incarnation," are "essentially people who think of themselves as being cooler than America," also referring to them as "the assassins of cool." He argues that metrosexuality is the hipster appropriation of gay culture, as a trait carried over from their "Emo" phase. He writes that "these aesthetics are assimilated—cannibalized—into a repertoire of meaninglessness, from which the hipster can construct an identity in the manner of a collage, or a shuffled playlist on an iPod." He also criticizes how the subculture's original menace has long been abandoned and has been replaced with "the form of not-quite-passive aggression called snark."


title: Hipster (contemporary subculture)

text: In a "Huffington Post" article entitled "Who's a Hipster?," Julia Plevin argues that the "definition of 'hipster' remains opaque to anyone outside this self-proclaiming, highly-selective circle." She claims that the "whole point of hipsters is that they avoid labels and being labeled. However, they all dress the same and act the same and conform in their non-conformity" to an "iconic carefully created sloppy vintage look."


title: Hipster (contemporary subculture)

text: Rob Horning developed a critique of hipsterism in his April 2009 article "The Death of the Hipster" in "PopMatters", exploring several possible definitions for the hipster. He muses that the hipster might be the "embodiment of postmodernism as a spent force, revealing what happens when pastiche and irony exhaust themselves as aesthetics," or might be "a kind of permanent cultural middleman in hypermediated late capitalism, selling out alternative sources of social power developed by outsider groups, just as the original 'white negros' evinced by Norman Mailer did to the original, pre-pejorative 'hipsters'—blacks." Horning also proposed that the role of hipsters may be to "appropriat[e] the new cultural capital forms, delivering them to mainstream media in a commercial form and stripping their inventors ... of the power and the glory." Horning argues that the "problem with hipsters" is the "way in which they reduce the particularity of anything you might be curious about or invested in into the same dreary common denominator of how 'cool' it is perceived to be," as "just another signifier of personal identity." Furthermore, he argues that the "hipster is defined by a lack of authenticity, by a sense of lateness to the scene" or the way that they transform the situation into a "self-conscious scene, something others can scrutinize and exploit."


title: Hipster (contemporary subculture)

text: Dan Fletcher in "Time" seems to support this theory, positing that stores like Urban Outfitters have mass-produced hipster chic, merging hipsterdom with parts of mainstream culture, thus overshadowing its originators' still-strong alternative art and music scene. According to Fletcher, "Hipsters manage to attract a loathing unique in its intensity. Critics have described the loosely defined group as smug, full of contradictions and, ultimately, the dead end of Western civilization."


title: Hipster (contemporary subculture)

text: Elise Thompson, an editor for the LA blog "LAist", argues that "people who came of age in the 70s and 80s punk rock movement seem to universally hate 'hipsters'," which she defines as people wearing "expensive 'alternative' fashion[s]," going to the "latest, coolest, hippest bar...[and] listen[ing] to the latest, coolest, hippest band." Thompson argues that hipsters "don't seem to subscribe to any particular philosophy ... [or] ... particular genre of music." Instead, she argues that they are "soldiers of fortune of style" who take up whatever is popular and in style, "appropriat[ing] the style[s]" of past countercultural movements such as punk, while "discard[ing] everything that the style stood for."


title: Hipster (contemporary subculture)

text: Drawing from Pierre Bourdieu's work and Thomas Frank's theories of co-optation, Zeynep Arsel and Craig Thompson argue that in order to segment and co-opt the indie marketplace, mass media and marketers have engaged in commercial "mythmaking" and contributed to the formation of the contemporary discourse about hipsters. They substantiate this argument using a historical discourse analysis of the term and its use in the popular culture, based on Arsel's dissertation that was published in 2007. Their claim is that the contemporary depiction of hipster is generated through mass media narratives with different commercial and ideological interests. In other words, hipster is less of an objective category, and more of a culturally- and ideologically-shaped and mass-mediated modern mythology that appropriates the indie consumption field and eventually turns into a form of stigma. Arsel and Thompson also interview participants of the indie culture (DJs, designers, writers) to better understand how they feel about being labeled as one. Their findings demonstrate three strategies for dissociation from the hipster stereotype: aesthetic discrimination, symbolic demarcation, and proclaiming sovereignty. These strategies, empowered by one's status in the indie field (or their cultural capital) enable these individuals to defend their field dependent cultural investments and tastes from devaluing hipster mythology.


title: Hipster (contemporary subculture)

text: Arsel and Thompson's work seeks to explain why people who are ostensibly fitting the hipster stereotype profusely deny being one: they argue that hipster mythology devalues their tastes and interests and thus they have to socially distinguish themselves from this cultural category and defend their tastes from devaluation. To succeed in denying being a hipster, while looking, acting, and consuming like one, Arsel and Thompson suggest that these individuals demythologize their existing consumption practices by engaging in rhetorics and practices that symbolically differentiate their actions from the hipster stigma.


title: Hipster (contemporary subculture)

text: Mark Greif, a founder of "n+1" and an assistant professor at The New School, in a "New York Times" editorial, states that "hipster" is often used by youth from disparate economic backgrounds to jockey for social position. He questions the contradictory nature of the label, and the way that no one thinks of themselves as a hipster: "Paradoxically, those who used the insult were themselves often said to resemble hipsters—they wore the skinny jeans and big eyeglasses, gathered in tiny enclaves in big cities, and looked down on mainstream fashions and 'tourists'." He believes the much-cited difficulty in analyzing the term stems from the fact that any attempt to do so provokes universal anxiety, since it "calls everyone's bluff." Like Arsel and Thompson, he draws from "La Distinction" by Pierre Bourdieu to conclude that young, upper-middle-class graduates who move to urban centers are ridiculed as "liberal arts college grads with too much time on their hands"; although "ignored in the urban hierarchy," they have cultural capital. Members of the upper class – ridiculed in turn as "trust fund hipsters" – "convert real capital into 'cultural capital'." At the bottom are the lower-middle-class young, who "seem most authentic but are also often the most socially precarious." Without the capital of the other groups, they depend on their fashion sense to maintain a sense of superiority.


title: Hipster (contemporary subculture)

text: Greif's efforts puts the term "hipster" into a socioeconomic framework rooted in the petit bourgeois tendencies of a youth generation unsure of their future social status. The cultural trend is indicative of a social structure with heightened economic anxiety and lessened class mobility.


title: Hipster (contemporary subculture)

text: In 21st-century society, there are inevitably people who refuse to conform to the dominant culture and seek to do the exact opposite; given enough time, the anti-conformists will become more homogeneous with respect to their own subculture, making their behavior the opposite to any claims of counterculture. This synchronization occurs even if more than two choices are available, such as multiple styles of beard rather than whether or not to have a beard. Mathematician Jonathan Touboul of Brandeis University who studies how information propagation through society affects human behavior calls this the hipster effect.


title: Rope (film)

text: Rope is a 1948 American psychological crime thriller film directed by Alfred Hitchcock, based on the 1929 play of the same name by Patrick Hamilton. The film was adapted by Hume Cronyn with a screenplay by Arthur Laurents.


title: Rope (film)

text: The film was produced by Hitchcock and Sidney Bernstein as the first of their Transatlantic Pictures productions. Starring James Stewart, John Dall and Farley Granger, this is the first of Hitchcock's Technicolor films, and is notable for taking place in real time and being edited so as to appear as four long shots through the use of stitched together long takes. It is the second of Hitchcock's "limited setting" films, the first being "Lifeboat" (1944). The original play was said to be inspired by the real-life murder of 14-year-old Bobby Franks in 1924 by University of Chicago students Nathan Leopold and Richard Loeb.


title: Rope (film)

text: Two brilliant young aesthetes, Brandon Shaw and Phillip Morgan, strangle to death their former classmate from prep school, David Kentley, in their Manhattan penthouse apartment. They commit the crime as an intellectual exercise: they want to prove their superiority by committing the "perfect murder".


title: Rope (film)

text: After hiding the body in a large antique wooden chest, Brandon and Phillip host a dinner party at the apartment, which has a panoramic view of Manhattan's skyline. The guests, who are unaware of what has happened, include the victim's father, Mr. Kentley, and aunt, Mrs. Atwater; his mother is unable to attend because of a cold. Also present are David's fiancée, Janet Walker, and her former lover, Kenneth Lawrence, who was once David's close friend.


title: Rope (film)

text: Brandon uses the chest containing the body as a buffet table for the food, just before their housekeeper, Mrs. Wilson, arrives to help with the party.


title: Rope (film)

text: Brandon and Phillip's idea for the murder was inspired years earlier by conversations with their prep-school housemaster, publisher Rupert Cadell. While they were at school, Rupert had discussed with them, in an apparently approving way, the intellectual concepts of Nietzsche's Superman, as a means of showing one's superiority over others. He, too, is among the guests at the party since Brandon, in particular, thinks that he would approve of their "work of art."


title: Rope (film)

text: Brandon's subtle hints about David's absence indirectly lead to a discussion on the "art of murder." Brandon appears calm and in control, although when he first speaks to Rupert, he is nervously excited and stammering. Phillip, on the other hand, is visibly upset and morose. He does not conceal it well and starts to drink too much.


title: Rope (film)

text: When David's aunt, Mrs. Atwater, who fancies herself a fortune-teller, tells him that his hands will bring him great fame, she refers to his skill at the piano, but he appears to think this refers to the notoriety of being a strangler.


title: Rope (film)

text: However, much of the conversation focuses on David and his strange absence, which worries the guests. A suspicious Rupert quizzes a fidgety Phillip about this and some of the inconsistencies raised in conversation. For example, Phillip vehemently denies ever strangling a chicken at the Shaws' farm, although Rupert has seen Phillip strangle several. Phillip later complains to Brandon about having had a "rotten evening," not because of David's murder, but because of Rupert's questioning.


title: Rope (film)

text: As the evening goes on, David's father and fiancée begin to worry because he has neither arrived nor phoned. Brandon increases the tension by playing matchmaker between Janet and Kenneth.


title: Rope (film)

text: Mrs. Kentley calls, overwrought because she has not heard from David, and Mr. Kentley decides to leave. He takes with him some books Brandon has given him, tied together with the rope Brandon and Phillip used to strangle his son.


title: Rope (film)

text: When Rupert leaves, Mrs. Wilson accidentally hands him David's monogrammed hat, further arousing his suspicion. Rupert returns to the apartment a short while after everyone else has departed, pretending that he has left his cigarette case behind. He asks for a drink and then stays to theorize about David's disappearance.